WO2025244063A1 - Light-emitting device and illumination device - Google Patents

Abstract

This light-emitting device is provided with a substrate part, a wavelength conversion member, a first light-emitting element, and a first heat-dissipation member. The wavelength conversion member emits illumination light on the basis of excitation light. The first light-emitting element is positioned between the substrate part and the wavelength conversion member, and emits excitation light. The first heat-dissipation member is positioned between the substrate part and the wavelength conversion member so as to be spaced apart from the first light-emitting element, and has a thermal conductivity higher than the thermal conductivity of the wavelength conversion member.

Description

Light-emitting device and lighting device CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Japanese Application No. 2024-84598 (filed May 24, 2024) and Japanese Application No. 2024-225061 (filed December 20, 2024), the entire disclosures of which are incorporated herein by reference.

This disclosure relates to light-emitting devices and lighting devices.

Patent Document 1 describes technology related to lighting devices.

JP 2015-84384 A

A light-emitting device is disclosed.

In one embodiment, the light-emitting device comprises a substrate, a wavelength conversion member, a first light-emitting element, and a first heat dissipation member. The wavelength conversion member emits illumination light based on excitation light. The first light-emitting element is located between the substrate and the wavelength conversion member and emits excitation light. The first heat dissipation member is located between the substrate and the wavelength conversion member, spaced apart from the first light-emitting element, and has a thermal conductivity higher than that of the wavelength conversion member.

In one embodiment, the lighting device comprises the light-emitting device, a cylindrical body, and a second heat dissipation member. The cylindrical body houses the light-emitting device. The second heat dissipation member contacts the first heat dissipation member and the inner surface of the cylindrical body.

FIG. 1 is a cross-sectional view schematically showing an example of the configuration of a light emitting device according to the first embodiment. FIG. 2 is a plan view schematically illustrating an example of the configuration of the light emitting device according to the first embodiment. FIG. 3 is a cross-sectional view schematically showing an example of the configuration of the light emitting device according to the second embodiment. FIG. 4 is a plan view schematically showing an example of the configuration of the light emitting device according to the second embodiment. FIG. 5 is an exploded perspective view schematically illustrating an example of the configuration of an illumination device according to the third embodiment. FIG. 6 is a cross-sectional view schematically showing an example of the configuration of a light emitting device according to the fourth embodiment. FIG. 7 is a plan view schematically showing an example of the configuration of a light emitting device according to the fifth embodiment. FIG. 8 is a cross-sectional view schematically showing an example of the configuration of a light emitting device according to the fifth embodiment. FIG. 9 is a plan view schematically showing a first example of the configuration of the light emitting device according to the sixth embodiment. FIG. 10 is a plan view schematically showing a second example of the configuration of the light emitting device according to the sixth embodiment. FIG. 11 is a plan view schematically illustrating an example of the configuration of a light emitting device according to the seventh embodiment. FIG. 12 is a diagram schematically illustrating an example of the electrical configuration of a light emitting device. FIG. 13 is a graph showing an example of the wavelength dependency of the absorptance of a phosphor. FIG. 14 is a cross-sectional view schematically showing a first example of the configuration of the light emitting device according to the eighth embodiment. FIG. 15 is a cross-sectional view schematically showing a second example of the configuration of the light emitting device according to the eighth embodiment. FIG. 16 is a cross-sectional view schematically showing a first example of the configuration of a light emitting device according to the ninth embodiment. FIG. 17 is a perspective view schematically illustrating an example of the configuration of an intermediate member and a first heat transfer member according to a first example of the ninth embodiment. FIG. 18 is a graph schematically showing an example of the temperature dependence of the thermal conductivity of sapphire. FIG. 19 is a diagram schematically illustrating an example of the positional relationship between the first opening and the first resin member. FIG. 20 is a cross-sectional view schematically showing a second example of the configuration of the light emitting device according to the ninth embodiment. FIG. 21 is a perspective view schematically illustrating an example of the configuration of a wavelength conversion member, an intermediate member, a first heat transfer member, and a second heat transfer member according to a second example of the ninth embodiment. FIG. 22 is a cross-sectional view schematically showing a third example of the configuration of the light emitting device according to the ninth embodiment. FIG. 23 is a diagram schematically illustrating an example of how the fluorescent light travels inside the supporting member. FIG. 24 is a cross-sectional view schematically showing a fourth example of the configuration of the light emitting device according to the ninth embodiment. FIG. 25 is a cross-sectional view schematically showing a first example of the configuration of a light emitting device according to the tenth embodiment. FIG. 26 is a plan view schematically showing a first example of the configuration of the light emitting device according to the tenth embodiment. FIG. 27 is a cross-sectional view schematically showing a first specific example of the configuration of a light emitting device in which a pressing portion 65 is not provided. FIG. 28 is a cross-sectional view schematically showing a second specific example of the configuration of a light emitting device in which a pressing portion 65 is not provided. FIG. 29 is a cross-sectional view schematically showing a third specific example of the configuration of a light emitting device in which a pressing portion 65 is not provided. FIG. 30 is a plan view schematically showing a second example of the configuration of the light emitting device according to the tenth embodiment. FIG. 31 is a perspective view schematically illustrating a first example of the configuration of an illumination device according to an eleventh embodiment. FIG. 32 is a perspective view schematically illustrating a second example of the configuration of the illumination device according to the eleventh embodiment. FIG. 33 is a cross-sectional view schematically showing an example of the configuration of a light emitting device according to the twelfth embodiment. FIG. 34 is a cross-sectional view schematically showing an example of the configuration of a light emitting device according to the thirteenth embodiment.

A light-emitting device is known that includes a housing, an LED (Light Emitting Diode) element, and a fluorescent material. The housing has a recess, and the LED element is located within the recess. The fluorescent material has a plate-like shape and is located so as to cover the opening of the recess in the housing. The fluorescent material includes a plate-like transparent material and a plurality of phosphor particles dispersed within the transparent material. The interior of the recess in the housing may be filled with a transparent resin that covers the LED element. Excitation light emitted from the LED element passes through the transparent resin and enters the fluorescent material. Each phosphor particle in the fluorescent material absorbs the excitation light and emits fluorescence. The fluorescence is emitted into external space, for example as illumination light.

In such light-emitting devices, it is desirable to increase the brightness of the illumination light.

The inventor has created a light-emitting device 1 that can improve brightness. An example of the light-emitting device 1 is described below.

First Embodiment
<Light-emitting device>
Fig. 1 is a cross-sectional view schematically showing an example of a part of the configuration of a light-emitting device 1 according to a first embodiment. Fig. 2 is a plan view schematically showing an example of a part of the configuration of the light-emitting device 1. In Fig. 2, various parts are omitted as appropriate. Fig. 1 shows a cross section taken along line II of Fig. 2.

The light-emitting device 1 includes a substrate 2, a light-emitting element 3 (corresponding to an example of a first light-emitting element), a wavelength conversion member 4, a first resin member 51, and a first heat dissipation member 6. Below, we will first provide an overview of an example of each component of the light-emitting device 1, and then provide a detailed description of each component.

The light-emitting element 3 is located on the substrate 2. The light-emitting element 3 emits excitation light. The wavelength conversion member 4 is located on the opposite side of the light-emitting element 3 from the substrate 2. In other words, the light-emitting element 3 is located between the wavelength conversion member 4 and the substrate 2. The wavelength conversion member 4 emits illumination light based on the excitation light from the light-emitting element 3. The illumination light is emitted into an external illumination space. In addition to emitting illumination light, the wavelength conversion member 4 also generates heat. When the temperature of the wavelength conversion member 4 increases due to this heat, the luminous efficiency of the wavelength conversion member 4 decreases.

The first heat dissipation member 6 is located between the substrate portion 2 and the wavelength conversion member 4. The thermal conductivity of the first heat dissipation member 6 is higher than that of the wavelength conversion member 4. Therefore, heat generated in the wavelength conversion member 4 can be dissipated to the outside through the first heat dissipation member 6. This reduces the possibility that the luminous efficiency of the wavelength conversion member 4 will decrease due to heat.

The first resin member 51 is located between the substrate portion 2 and the wavelength conversion member 4, and has an annular shape that surrounds the light-emitting element 3 in a planar view. The first resin member 51 is located closer to the light-emitting element 3 than the first heat dissipation member 6. Conversely, the first heat dissipation member 6 is located outside the first resin member 51, and is adjacent to the first resin member 51 with a gap between them.

The first resin member 51 may be reflective to the excitation light. If the first resin member 51 is reflective, the excitation light traveling from the light-emitting element 3 toward the first resin member 51 is reflected by the first resin member 51, and a portion of the reflected light enters the wavelength conversion member 4. Therefore, the inner diameter of the first resin member 51 defines the incidence area of the excitation light on the wavelength conversion member 4. Because the first resin member 51 surrounds the light-emitting element 3 at a position closer to the light-emitting element 3 than the first heat dissipation member 6, the inner diameter of the first resin member 51 can be made smaller. This allows the incidence area of the wavelength conversion member 4 to be made smaller. In other words, the excitation light is concentrated in a narrower incidence area.

Since the wavelength conversion member 4 emits illumination light based on the excitation light, the incident area can correspond to the emission area of the illumination light. This allows the wavelength conversion member 4 to emit illumination light with a smaller output diameter and higher brightness. The total luminous flux of the illumination light may be, for example, 800 lumens or more. However, since high-brightness excitation light is incident on the wavelength conversion member 4, there is a high possibility of thermal degradation of the wavelength conversion member 4. However, in this embodiment, the light emitting device 1 includes the first heat dissipation member 6, which allows heat from the wavelength conversion member 4 to be effectively dissipated. Therefore, the light emitting device 1 can emit high-brightness illumination light with high reliability.

<Board>
As shown in FIG. 1 , the substrate unit 2 may include a substrate 21 and an insulating film 22. The substrate 21 may have a plate-like shape. The substrate 21 has a first surface 21a and a second surface 21b. The first surface 21a is a surface facing the second surface 21b in the thickness direction of the substrate 21. The first surface 21a and the second surface 21b may be flat surfaces. The substrate 21 may have a rectangular shape in a planar view. Here, a planar view refers to viewing an object with the line of sight along the thickness direction of the substrate 21. For example, the substrate 21 may have a square shape. The substrate 21 may have high thermal conductivity. This can improve the heat dissipation performance of the light-emitting device 1. The thermal conductivity of the substrate 21 may be higher than that of the wavelength conversion member 4, which will be described later. For example, the substrate 21 may be formed of a metal such as copper or aluminum, or a ceramic such as alumina.

The insulating film 22 is located on the first surface 21a of the substrate 21. The insulating film 22 may be located over the entire first surface 21a of the substrate 21. The insulating film 22 may be, for example, an oxide film or a nitride film.

As shown in FIG. 1, a conductive pattern 7 may be located on the insulating film 22. The conductive pattern 7 is a pattern for supplying power to the light-emitting element 3. The conductive pattern 7 is formed of a metal such as gold. The conductive pattern 7 includes a first conductive pattern 71 and a second conductive pattern 72. A DC voltage is applied between the first conductive pattern 71 and the second conductive pattern 72 by a power supply (not shown). The conductive pattern 7 can also be said to belong to the substrate portion 2. The substrate portion 2 can also be said to be a wiring board.

As shown in FIG. 2, the second conductive pattern 72 may include an element electrode 72a, an external electrode 72b, and wiring 72c. The element electrode 72a may have a circular shape in a planar view. The element electrode 72a may be located in the center of the substrate 21 in a planar view. As described below, the light-emitting element 3 is electrically connected to the element electrode 72a.

The external electrode 72b may be located at a corner of the substrate 21 in a plan view. The external electrode 72b may have a rectangular shape in a plan view. One end of the wiring 86 is connected to the external electrode 72b.

The wiring 72c electrically connects the element electrode 72a and the external electrode 72b. The wiring 72c has a strip shape and may extend linearly from the element electrode 72a to the external electrode 72b. The wiring 72c extends, for example, along a diagonal line of the substrate 21. The diameter of the element electrode 72a may be larger than the width of the wiring 72c, and the diagonal length of the external electrode 72b may be larger than the width of the wiring 72c.

As shown in FIG. 2, the first conductive pattern 71 may include an element electrode 71a, an external electrode 71b, and wiring 71c. As shown in FIG. 2, the element electrode 71a may have an arc shape concentric with the element electrode 72a. The element electrode 71a is aligned radially with the element electrode 72a at a distance. The element electrode 71a may be positioned radially outward of the element electrode 72a. The central angle of the element electrode 71a may be greater than 180 degrees. The wiring 72c extends, passing between both ends of the arc of the element electrode 71a. The light-emitting element 3 is electrically connected to the element electrode 71a, as described below.

In a plan view, the external electrode 71b may be located at a corner of the substrate 21 that is diagonally opposite the external electrode 72b. The external electrode 71b may have a rectangular shape in a plan view. One end of the wiring 85 is connected to the external electrode 71b.

The wiring 71c electrically connects the element electrode 71a and the external electrode 71b. The wiring 71c extends, for example, along a diagonal line of the substrate 21. The inner diameter of the element electrode 71a may be larger than the width of the wiring 71c, and the diagonal length of the external electrode 71b may be larger than the width of the wiring 71c.

<Light-emitting element>
The light-emitting element 3 emits excitation light. Monochromatic light such as purple, blue-violet, or blue is used as the excitation light. More specifically, the excitation light may be any of purple light having an intensity peak at a wavelength of 405 nanometers (nm), blue-violet light having an intensity peak at a wavelength of 420 nm, and blue light having an intensity peak at a wavelength of 450 nm.

The light-emitting element 3 is located on the substrate portion 2. The light-emitting element 3 may have a plate-like shape. The light-emitting element 3 may be located on the substrate portion 2 with its thickness direction aligned with the thickness direction of the substrate 21. The light-emitting element 3 has a first surface 3a and a second surface 3b that face each other in the thickness direction, with the second surface 3b located on the substrate portion 2 side. A first element electrode (not shown) may be formed on the first surface 3a, and a second element electrode (not shown) may be formed on the second surface 3b.

The light-emitting element 3 is, for example, a semiconductor light-emitting element. As a specific example, the light-emitting element 3 includes a p-type semiconductor layer, an n-type semiconductor layer, a first element electrode, and a second element electrode. The p-type semiconductor layer and the n-type semiconductor layer are adjacent in the thickness direction and can be bonded to each other. The first element electrode is connected to one of the p-type and n-type semiconductor layers, and the second element electrode is connected to the other of the p-type and n-type semiconductor layers. The first element electrode and the second element electrode are formed of, for example, metal. When a DC voltage is applied between the first element electrode and the second element electrode, excitation light is generated, for example, at the junction between the p-type semiconductor layer and the n-type semiconductor layer. The light-emitting element 3 is, for example, an LED (Light Emitting Diode) element.

As shown in FIG. 1, the light-emitting element 3 may be located on an element electrode 72a (corresponding to an example of a first electrode) of the second conductive pattern 72. The second element electrode on the second surface 3b of the light-emitting element 3 is electrically connected to the element electrode 72a. For example, the second element electrode of the light-emitting element 3 may be connected to the element electrode 72a by an electrode material such as solder. The first element electrode of the light-emitting element 3 is connected to the element electrode 71a of the first conductive pattern 71, for example, via a wire 31.

When a power supply (not shown) outputs a voltage between the first conductive pattern 71 and the second conductive pattern 72 via wiring 85 and wiring 86, the light-emitting element 3 emits excitation light. As the light is emitted, the light-emitting element 3 also generates heat. This heat is transferred to the substrate 21, for example, via the insulating film 22.

<Reflective material>
As shown in FIG. 1 , the light emitting device 1 may further include a reflective material 8. The reflective material 8 is located on the conductive pattern 7 and the insulating film 22 at a position adjacent to the light emitting element 3 in a planar view. The reflective material 8 may be located in an area that does not overlap with the light emitting element 3 in a planar view. The reflective material 8 may be in contact with the entire periphery of the side surface of the light emitting element 3. In a planar view, the reflective material 8 is located between the first heat dissipation member 6 (described below) and the light emitting element 3. The reflective material 8 has insulating properties. This reduces the possibility of a short circuit occurring between the first conductive pattern 71 and the second conductive pattern 72.

The reflector 8 is reflective to excitation light or illumination light. The reflectance (maximum value) of the reflector 8 to excitation light or illumination light may be, for example, 50% or more, 60% or more, 70% or more, 80% or more, or 90% or more. The reflector 8 is formed, for example, from resin.

<Wavelength conversion material>
The wavelength conversion member 4 is located on the opposite side of the substrate unit 2 with respect to the light-emitting element 3. In other words, the light-emitting element 3 is located between the wavelength conversion member 4 and the substrate unit 2. The wavelength conversion member 4 faces the light-emitting element 3 at an interval in the thickness direction of the substrate 21. Excitation light from the light-emitting element 3 is incident on the wavelength conversion member 4. The wavelength conversion member 4 emits illumination light based on the excitation light. The wavelength conversion member 4 absorbs, for example, the excitation light and emits illumination light having a wavelength different from the wavelength of the excitation light. The wavelength conversion member 4 contains, for example, a phosphor. In this case, the illumination light is fluorescence. The wavelength conversion member 4 may be made of an inorganic material. The wavelength conversion member 4 may be ceramic. The wavelength conversion member 4 may include any one of a sintered body, glass, crystallized glass, and crystal.

The crystal includes, for example _, polycrystalline ceramics obtained by dispersing phosphor particles in polycrystalline aluminum oxide ( _Al2O3 ) and sintering _the resulting material. The volume concentration of _Al2O3 is, for example, 80 vol% or more and 99.99 vol% or less, and the volume concentration of the phosphor particles is, for example, 0.01 vol% or more and 20 vol% or less. An example of the phosphor particles will be described later.

The glass contains, for example, calcium oxide (CaO ₂ ), Al ₂ O ₃ , silicon oxide (SiO ₂ ), aluminum nitride (AlN), and at least one of rare earth elements. The rare earth elements include at least one of cerium (Ce), praseodymium (Pr), europium (Eu), terbium (Tb), dysprosium (Dy), thulium (Tm), erbium (Er), and neodymium (Nd). The molar concentration of CaO ₂ is, for example, 0 mol% or more and 50 mol% or less, the molar concentration of Al ₂ O ₃ is, for example, 0 mol% or more and 30 mol% or less, the molar concentration of SiO ₂ is, for example, 5 mol% or more and 60 mol% or less, the molar concentration of AlN is, for example, 5 mol% or more and 40 mol% or less, and the molar concentration of the rare earth elements is, for example, 0.1 mol% or more and 20 mol% or less.

The crystallized glass contains, for example, Al ₂ O ₃ , SiO ₂ , and M, which will be described below, as a base glass. M includes at least one of magnesium oxide (MgO), CaO, strontium oxide (SrO), barium oxide (BaO), and yttrium oxide (Y ₂ O ₃ ). The molar concentration of SiO ₂ is, for example, 5 mol% or more and 50 mol% or less, the molar concentration of Al ₂ O ₃ is, for example, 10 mol% or more and 50 mol% or less, and the molar concentration of M is, for example, 5 mol% or more and 70 mol% or less. The crystallized glass may further contain at least one of titanium oxide (TiO ₂ ), zirconium oxide (ZrO ₂ ), phosphorus oxide (P ₂ O ₅ ), and lithium oxide (Li ₂ O). The molar concentration of the total amount of these is, for example, 0 mol% or more and 10 mol% or less. The crystallized glass may contain a rare earth element as an activator. Examples of the rare earth element are as described above. The molar concentration of the rare earth element is, for example, 0.01 mol % or more and 5 mol % or less.

The crystals include, for example, (Y,Gd) ₃ (Al,Ga) ₅ O ₁₂ :Ce ³⁺ single crystals or eutectic with sapphire.

Alternatively, the wavelength conversion member 4 may include a plurality of phosphor particles 41 and a binder layer 42 that binds the plurality of phosphor particles 41 together. Each of the plurality of phosphor particles 41 is, for example, a phosphor particle that absorbs excitation light and emits fluorescence. The plurality of phosphor particles 41 may include, for example, one or more types of phosphor particles that emit fluorescence of one or more wavelength spectra different from the wavelength spectrum of the excitation light in response to irradiation with excitation light. The one or more types of phosphor particles may include, for example, multiple types of phosphor particles that emit fluorescence having mutually different wavelength spectra in response to irradiation with excitation light. The multiple types of phosphor particles may include, for example, red phosphor particles, green phosphor particles, and blue phosphor particles. The red phosphor is a phosphor that emits red (R) fluorescence in response to irradiation with excitation light. The green phosphor is a phosphor that emits green (G) fluorescence in response to irradiation with excitation light. The blue phosphor is a phosphor that emits blue (B) fluorescence in response to irradiation with excitation light.

The phosphor that constitutes the multiple phosphor particles may be, for example, a phosphor containing a rare earth such as europium (Eu), cerium (Ce), or yttrium (Y) in the form of a compound such as a phosphate, oxide, silicate, nitride, fluoride, aluminate, or sulfide.

The red phosphor may be, for example, a phosphor whose peak fluorescence intensity wavelength in response to irradiation with excitation light is in the range of approximately 620 nm to 750 _nm . Examples of materials for the red phosphor include _CaAlSiN3 :Eu, _Y3O3S :Eu, _Y3O3 :Eu, SrCaClAlSiN3:Eu2 ⁺ _, and CaAlSi(ON) _{3 :} Eu. The red phosphor particles may be, for example, phosphor particles that do not contain phosphorus (P) (also referred to as non-phosphorus phosphor particles), or phosphor particles that contain nitride.

The green phosphor may be, for example, a phosphor whose peak fluorescence intensity wavelength in response to irradiation with excitation light is in the range of approximately 495 nm to 570 nm. Examples of materials that may be used for the green phosphor include β-sialon (β-SiAlON:Eu), SrSi ₂ (O, Cl) ₂ N ₂ :Eu, (Sr, Ba, Mg) ₂ SiO ₄ :Eu ₂ ²⁺ , ZnS:Cu, Al, and Zn ₂ SiO ₄ :Mn. For example, phosphor particles that do not contain phosphorus (P) (non-phosphorus phosphor particles) or phosphor particles containing nitride may be used as the phosphor particles of the green phosphor.

The blue phosphor may be, for example, a phosphor that emits fluorescent light in response to irradiation with excitation light with a peak intensity wavelength in the range of approximately 450 nm to 495 nm. Examples of materials that may be used for the blue phosphor include (Ba,Sr) _MgAl10O17 :Eu, _BaMgAl10O17 :Eu, (Sr,Ca,Ba) ₁₀ ( _PO4 ) _6Cl2 : _{Eu, (Sr,Ba)10 ( PO4 ) 6Cl2} : _{Eu ,} and α-sialon. Examples of phosphor particles that may be used for the blue phosphor include phosphor particles containing phosphorus (P) (also referred to as phosphorus-based phosphor particles), and phosphor particles containing nitride.

The particle size of the phosphor particles 41 may be, for example, approximately 5 micrometers (μm) to 50 μm.

The phosphor particles 41 generate heat when they absorb the excitation light. This can cause the temperature of the phosphor particles 41 to rise. If the temperature of the phosphor particles 41 increases, the luminous efficiency of the phosphor particles 41 may decrease. The luminous efficiency of the phosphor particles 41 here refers to, for example, the ratio of the number of photons of the fluorescent light from the phosphor particles 41 to the number of photons of the excitation light incident on the phosphor particles 41. If the temperature of the phosphor particles 41 increases too much, the phosphor particles 41 may quench. Such a decrease in the luminous efficiency and quenching of the phosphor particles 41 is undesirable, so it is desirable to mitigate the temperature rise of the phosphor particles 41.

The binder layer 42 is translucent for excitation light and fluorescence. The binder layer 42 bonds multiple phosphor particles 41 together. In other words, the wavelength conversion member 4 has a form in which multiple phosphor particles 41 are dispersed in the binder layer 42. The binder layer 42 may be made of, for example, resin or glass. In other words, the binder layer 42 includes an organic resin or an inorganic material. The binder layer 42 may include glass as a primary inorganic material. The term "primary component" refers to the component that is contained in the largest proportion (also referred to as the content) of the components constituting the substance. Glass is translucent, for example, to allow excitation light to penetrate into the interior of the wavelength conversion member 4 and to radiate fluorescence emitted by phosphor particles excited in response to irradiation with excitation light to the outside of the wavelength conversion member 4. In other words, glass is translucent, for example, to allow excitation light and fluorescence to pass through. The binder layer 42 may also be referred to as a glass matrix. If the binder layer 42 is formed from an inorganic material (e.g., a glass matrix), the binder layer 42 is less susceptible to thermal degradation than an organic resin.

For example, low-melting-point glass may be used as the glass constituting the binder layer 42. For example, oxide glass having a melting point (Tm) of 200 degrees Celsius (200°C) to 700°C may be used as the low-melting-point glass. The oxide glass serving as the low-melting-point glass has a glass transition point (Tg) in the range of 100°C to 600°C and a crystallization temperature (Tc) in the range of 150°C to 650°C. The oxide glass may be, for example, a _glass containing two or more oxides _selected from silicon _dioxide ( _SiO2 ), aluminum oxide ( _Al2O3 ), boron oxide ( _B2O3 ), sodium oxide ( _Na2O3 ), potassium oxide ( _K2O ), lithium oxide ( _Li2O ), calcium oxide (CaO), barium oxide (BaO), zinc oxide ₍ ZnO), lead monoxide (PbO), and diphosphorus pentoxide ( _P2O5 ) as its main components. In other words, the oxide glass may contain an oxide of a metal element or an oxide of a metalloid element.

The binder layer 42 contains, for example, an amorphous phase of glass. This amorphous phase may be, for example, the amorphous phase portion of a low-melting-point glass. The amorphous phase made of glass has translucency, allowing, for example, excitation light and fluorescent light to pass through.

<First resin member>
The first resin member 51 is located between the substrate unit 2 and the wavelength conversion member 4. As shown in FIG. 2, the first resin member 51 may have an annular shape in a planar view. The first resin member 51 may be located so as to surround the light-emitting element 3 in a planar view (see also FIG. 1). The first resin member 51 may also be called a dam member. In a planar view, the inner contour (i.e., inner peripheral edge) of the first resin member 51 may be located outside the contour of the light-emitting element 3. In other words, the light-emitting element 3 does not need to overlap the first resin member 51 in a planar view. In this case, the first resin member 51 can seal the light-emitting element 3 in a sealed space. The light-emitting element 3 may also partially overlap the first resin member 51 in a planar view. As shown in FIG. 1, the first resin member 51 may be in contact with the reflector 8 and the wavelength conversion member 4. The first resin member 51 may be bonded to the reflector 8 and the wavelength conversion member 4, respectively.

The first resin member 51 may be reflective to the excitation light. The reflectance of the first resin member 51 to the excitation light may be, for example, 50% or more, 60% or more, 70% or more, 80% or more, or 90% or more. The first resin member 51 may be reflective to the illumination light. The reflectance (maximum value) of the first resin member 51 to the illumination light may be, for example, 50% or more, 60% or more, 70% or more, 80% or more, or 90% or more. The first resin member 51 may have a white surface, for example.

The first resin member 51 may be insulating. The first resin member 51 includes a resin such as epoxy resin, phenolic resin, polyphthalamide, silicone resin, synthetic rubber, natural rubber, or silicone rubber. The first resin member 51 may include a reflective material with a refractive index significantly different from that of the above resin, such as a powder of at least one of titanium oxide, aluminum oxide, and magnesium oxide. Alternatively, the first resin member 51 may include a filler such as silver, aluminum, or aluminum oxide as a reflective material with high reflectivity. This can improve the reflectivity of the first resin member 51.

If the first resin member 51 is reflective, part of the excitation light emitted by the light-emitting element 3 is reflected by the first resin member 51 and enters the wavelength conversion member 4. This allows the excitation light to be concentrated on the part of the wavelength conversion member 4 that is surrounded by the first resin member 51 in a planar view. As a result, the wavelength conversion member 4 can emit illumination light with a smaller emission diameter and higher brightness. On the other hand, because high-brightness excitation light enters the wavelength conversion member 4, the amount of degradation due to heat increases.

The first resin member 51 can be formed as follows. That is, the first resin member 51 is applied in a ring shape before solidification and has a high viscosity, and then the first resin member before solidification is solidified using a curing agent, heat, light, or the like, thereby forming the first resin member 51. Here, solidification includes the hardening of the resin. Because the viscosity of the first resin member 51 before solidification is high, the first resin member 51 can be molded into a ring shape with high precision. In other words, the emission diameter can be adjusted with even greater precision.

As shown in FIG. 1, the first resin member 51 may partially face the element electrode 71a in the thickness direction of the substrate 21. In other words, at least a portion of the first resin member 51 may overlap at least a portion of the element electrode 71a in a planar view. This allows the inner diameter of the first resin member 51 to be made smaller. As a result, the wavelength conversion member 4 can emit illumination light with an even smaller emission diameter and higher brightness. At least a portion of the first resin member 51 may overlap at least a portion of the element electrode 72a. In this case, the wavelength conversion member 4 can emit illumination light with an even smaller emission diameter and higher brightness.

<First heat dissipation member>
The first heat dissipation member 6 is located between the substrate 2 and the wavelength conversion member 4. The first heat dissipation member 6 is located outside the first resin member 51 in a planar view. The first heat dissipation member 6 is not in contact with the first resin member 51 and is separated from the first resin member 51 in a planar view. In other words, the first heat dissipation member 6 is adjacent to the first resin member 51 at an interval in a direction parallel to the first surface of the substrate 21. The first heat dissipation member 6 may be located in a region avoiding the conductive pattern 7 in a planar view. The first heat dissipation member 6 may have a plate-like shape. The first heat dissipation member 6 may have a first surface 6a and a second surface 6b facing each other in the thickness direction of the substrate 21. The first surface 6a and the second surface 6b may be flat surfaces. A portion of the first surface 6a of the first heat dissipation member 6 may face the peripheral edge of the wavelength conversion member 4 in the thickness direction of the substrate 21. The portion of the first surface 6a of the first heat dissipation member 6 may be in contact with the peripheral portion of the wavelength conversion member 4. Here, the peripheral portion of the wavelength conversion member 4 may include, for example, a region within 0.5 mm from the outer periphery of the wavelength conversion member 4. The first heat dissipation member 6 allows heat from the wavelength conversion member 4 to be dissipated to the substrate portion 2. This reduces the risk of a decrease in luminous efficiency due to thermal quenching of the wavelength conversion member 4. Although brightness can be increased by making the first resin member 51 a reflective member, as described above, there is a risk that the degree of thermal degradation of the wavelength conversion member 4 may increase. For this reason, it is particularly effective to improve the heat dissipation properties of the phosphor in such lighting devices.

An adhesive member 23 may be positioned between the second surface 6b of the first heat dissipation member 6 and the insulating film 22 of the substrate portion 2. The adhesive member 23 may be, for example, heat dissipation grease. Heat dissipation grease may contain, for example, a resin such as silicone and a highly thermally conductive filler dispersed in the resin.

The first heat dissipation member 6 has a thermal conductivity higher than that of the wavelength conversion member 4. For example, the first heat dissipation member 6 may be made of a metal such as copper or aluminum, a ceramic such as alumina, or a single crystal such as sapphire.

As shown in FIG. 2, the first heat dissipation member 6 may include heat dissipation members 61 and 62. In a plan view, the heat dissipation members 61 and 62 are located on opposite sides of the conductive pattern 7. The heat dissipation members 61 and 62 may have the same shape. The first heat dissipation member 6 may have a substantially right-angled triangular shape, with a recess 6c formed on its hypotenuse. The recess 6c may be formed adjacent to the element electrode 71a in a plan view with a gap therebetween. The recess 6c may have an arc shape concentric with the element electrode 71a. This allows the gap between the first heat dissipation member 6 and the conductive pattern 7 to be narrowed. In other words, the area of the first heat dissipation member 6 can be increased. This effectively improves the heat dissipation performance of the light emitting device 1. The area of the first heat dissipation member 6 in a plan view may be more than half the area of the substrate 21.

<Filling material>
As shown in FIG. 1 , a filler 53 may be located in the region surrounded by the first resin member 51. The filler 53 may tightly cover the light-emitting element 3. In other words, the filler 53 may seal the light-emitting element 3. The filler 53 may be bonded to the wavelength conversion member 4 or the first resin member 51. The filler 53 has insulating properties and light-transmitting properties. For example, the transmittance of the filler 53 for excitation light may be 70% or more, 80% or more, 90% or more, or 95% or more. The transmittance (maximum value) of the filler 53 for illumination light may be 70% or more, 80% or more, 90% or more, or 95% or more. The filler 53 may be solid or liquid. As a specific example, the filler 53 may be a resin such as an epoxy resin or a silicone resin. A portion of the filler 53 may be located outside the first resin member 51 between the wavelength conversion member 4 and the substrate unit 2. The filler 53 can protect the light emitting element 3 from external factors such as moisture.

The filler 53 can be formed as follows. That is, the filler 53 can be formed by applying the filler 53 before solidification to an area inside the first resin member 51 and then solidifying the filler 53 before solidification using a curing agent, heat, light, or the like. The viscosity of the filler 53 before solidification may be lower than the viscosity of the first resin member 51 before solidification. In this way, the fluidity of the filler 53 before solidification is high, and the filler 53 before solidification can easily fill the space inside the first resin member 51.

In this light-emitting device 1, the light-emitting element 3 emits excitation light. Specifically, a portion of the excitation light from the light-emitting element 3 passes through the filler 53 and enters the wavelength conversion member 4. The light-emitting element 3 generates heat as it emits the excitation light. The heat generated by the light-emitting element 3 mainly travels through the insulating film 22 to the substrate 21 and is released to the outside.

The wavelength conversion member 4 emits illumination light based on the excitation light. The wavelength conversion member 4 generates heat as it emits this illumination light. The heat generated by the wavelength conversion member 4 is transferred mainly to the substrate 21 or to the outside via the first heat dissipation member 6. Because the thermal conductivity of the first heat dissipation member 6 is higher than that of the wavelength conversion member 4, it can effectively dissipate heat from the wavelength conversion member 4. This reduces the degree of thermal deterioration of the wavelength conversion member 4. In other words, the light emitting device 1 can continue to emit illumination light with high brightness for a longer period of time.

If the first resin member 51 is reflective to excitation light, excitation light traveling from the light-emitting element 3 toward the first resin member 51 is reflected by the first resin member 51, and some of the excitation light may enter the wavelength conversion member 4. Excitation light traveling from the light-emitting element 3 toward the element electrode 72a is reflected by the element electrode 72a, and as a result, some of the excitation light enters the wavelength conversion member 4. Excitation light from the side of the light-emitting element 3 is reflected by the reflector 8, and may enter the wavelength conversion member 4 while being reflected by other members.

Because the first resin member 51 surrounds the light-emitting element 3, the excitation light is incident on the wavelength conversion member 4 in an incident region surrounded by the first resin member 51. In other words, the excitation light is concentrated on the incident region of the wavelength conversion member 4. This allows the wavelength conversion member 4 to emit brighter illumination light with a smaller exit diameter. However, since brighter excitation light is incident on the wavelength conversion member 4, the degree of thermal degradation of the wavelength conversion member 4 increases. In this embodiment, the first heat dissipation member 6, which is located outside the first resin member 51, can effectively dissipate heat from the wavelength conversion member 4. This allows the light-emitting device 1 to emit brighter illumination light with high reliability.

If metal is used as the material for the first heat dissipation member 6, its high thermal conductivity will further improve the heat dissipation performance of the light emitting device 1. Furthermore, as shown in Figure 2, if the first heat dissipation member 6 is positioned in an area that does not overlap with the conductive pattern 7 in a planar view, insulation between the conductive first heat dissipation member 6 and the conductive pattern 7 can be more reliably ensured.

Now, let us consider a structure in which the first resin member 51 is not provided. In this structure, some of the excitation light from the light-emitting element 3 may be reflected by the side surface of the first heat dissipation member 6 and enter the wavelength conversion member 4. As a result, the excitation light may also enter the area of the wavelength conversion member 4 near the side surface of the first heat dissipation member 6. In other words, the incident area of the wavelength conversion member 4 becomes wider, which results in an increase in the emission diameter of the illumination light and a decrease in the brightness of the illumination light.

In contrast, in this embodiment, the first resin member 51 surrounds the light-emitting element 3 at a position closer to the light-emitting element 3 than the first heat dissipation member 6 in a planar view. Although the element electrodes 71a and 72a are also close to the light-emitting element 3 at a position closer to the light-emitting element 3, the proximity of the insulating first resin member 51 to the element electrodes 71a and 72a does not lead to electrical problems such as discharge. For example, the first resin member 51 can be positioned directly above the element electrode 71a. Furthermore, if the first resin member 51 is reflective, the first resin member 51 can narrow the incident area of the wavelength conversion member 4, thereby increasing the brightness of the illumination light while reducing the emission diameter of the illumination light.

Second Embodiment
Fig. 3 is a cross-sectional view schematically showing an example of a part of the configuration of the light emitting device 1 according to the second embodiment. Fig. 4 is a plan view schematically showing an example of a part of the configuration of the light emitting device 1 according to the second embodiment. The light emitting device 1 according to the second embodiment differs from the light emitting device 1 according to the first embodiment in the size of the wavelength conversion member 4 and the presence or absence of the intermediate member 5.

In the second embodiment, the indirect member 5 is located between the wavelength conversion member 4 and the first resin member 51. It can also be said that the indirect member 5 is located between the wavelength conversion member 4 and the first heat dissipation member 6. The indirect member 5 may have a plate-like shape. The indirect member 5 has a first surface 5a and a second surface 5b that face each other in the thickness direction. As shown in FIG. 4, the indirect member 5 may have a rectangular shape in a planar view. As an example, the indirect member 5 may have a square shape. One side of the indirect member 5 may be parallel to one side of the substrate 21.

Referring to FIG. 3, at least one of the first resin member 51 and the filler 53 may be in contact with the second surface 5b of the intermediate member 5. At least one of the first resin member 51 and the filler 53 may be bonded to the second surface 5b of the intermediate member 5. The peripheral edge of the lower surface of the intermediate member 5 faces a part of the upper surface of the first heat dissipation member 6 in the thickness direction. This peripheral edge of the intermediate member 5 may be in contact with this part of the first heat dissipation member 6, and a highly thermally conductive resin such as thermal grease may be located between the intermediate member 5 and the first heat dissipation member 6. Here, the peripheral edge of the intermediate member 5 may include an area within 1 mm from the outer periphery of the intermediate member 5.

The indirect member 5 is translucent to the excitation light. The transmittance of the indirect member 5 to the excitation light may be, for example, 80% or more, 90% or more, 95% or more, or 98% or more. The indirect member 5 may be translucent to the illumination light. The transmittance of the indirect member 5 to the illumination light may be, for example, 80% or more, 90% or more, 95% or more, or 98% or more. The indirect member 5 is formed, for example, from a transparent ceramic such as sapphire, glass, or crystallized glass.

The thermal conductivity of the indirect member 5 is higher than that of air and may be higher than that of the wavelength conversion member 4. If the indirect member 5 is sapphire, the thermal conductivity of the indirect member 5 is sufficiently higher than that of the wavelength conversion member 4. The thermal conductivity of the indirect member 5 may be lower than that of the first heat dissipation member 6.

The heat generated in the wavelength conversion member 4 is transferred via the intermediate member 5, which has high thermal conductivity, to the first heat dissipation member 6, which also has high thermal conductivity. This allows the temperature of the wavelength conversion member 4 to be further reduced.

The wavelength conversion member 4 is located on the first surface 5a of the intermediate member 5. As shown in FIG. 4, the wavelength conversion member 4 may have a circular shape in a planar view. The diameter of the wavelength conversion member 4 is shorter than one side of the intermediate member 5. In a planar view, the periphery of the wavelength conversion member 4 may be located outside the inner periphery of the first resin member 51. In other words, the diameter of the wavelength conversion member 4 may be larger than the inner diameter of the first resin member 51. This allows the excitation light to more appropriately enter the wavelength conversion member 4. Conversely, the amount of excitation light that does not enter the wavelength conversion member 4 can be reduced.

In plan view, the periphery of the wavelength conversion member 4 may be located inside the outer periphery of the first resin member 51. In other words, the diameter of the wavelength conversion member 4 may be smaller than the outer diameter of the first resin member 51. In this case, the size of the wavelength conversion member 4 can be reduced, which allows the light emitting device 1 to be made more compact and the cost of the light emitting device 1 to be reduced.

The wavelength conversion member 4 may contain multiple types of phosphor particles 41 and a binder layer 42. This can improve the wavelength conversion performance (i.e., luminous efficiency) of the wavelength conversion member 4. However, the breaking strength of the wavelength conversion member 4 alone is not very high. For this reason, the wavelength conversion member 4 may be fixed to the intermediate member 5. For example, the binder layer 42 of the wavelength conversion member 4 may be bonded to the first surface 5a of the intermediate member 5. Furthermore, the breaking strength of the intermediate member 5 may be higher than that of the wavelength conversion member 4. For example, if the intermediate member 5 is sapphire, the breaking strength of the intermediate member 5 is sufficiently higher than that of the wavelength conversion member 4. Specifically, the breaking strength can be evaluated as bending strength using a method that partially complies with JIS R1601 or ISO 23242. For example, if the intermediate member 5 is sapphire, the bending strength can reach 960 MPa. On the other hand, the bending strength of the wavelength conversion member 4 can reach 50 MPa. Therefore, the reliability of the light emitting device 1 can be improved compared to the first embodiment.

Third Embodiment
5 is an exploded perspective view schematically illustrating an example of the configuration of an illumination device 10 according to the third embodiment. The illumination device 10 includes a light-emitting device 1, a second heat dissipation member 91, a heat sink 92, and a cylindrical body 93.

The heat sink 92 has a first surface 92a that is larger than the second surface 21b of the substrate 21. The first surface 92a of the heat sink 92 may be in contact with the second surface 21b of the substrate 21, or a highly thermally conductive resin such as thermal grease may be positioned between the heat sink 92 and the substrate 21. The thermal conductivity of the heat sink 92 is higher than that of the wavelength conversion member 4. The heat sink 92 is formed from a metal such as copper or aluminum.

The heat sink 92 may include a plate portion 921 and a plurality of fins 922. The plate portion 921 has a first surface 92a. A plurality of fins 922 are provided on a second surface 92b of the plate portion 921, which is opposite the first surface 92a. The second surface 92b is the surface that faces the first surface 92a in the thickness direction of the plate portion 921. The multiple fins 922 protrude from the second surface 92b of the plate portion 921. This can improve the heat dissipation properties of the heat sink 92.

The second heat dissipation member 91 is in contact with the first heat dissipation member 6 of the light-emitting device 1. The second heat dissipation member 91 may have a plate-like shape. An opening 91a is formed in the center of the second heat dissipation member 91. The opening 91a penetrates the second heat dissipation member 91 in its thickness direction. The opening 91a may have a circular shape in a planar view. The second heat dissipation member 91 is attached to the light-emitting device 1 so that the light-emitting element 3 and the wavelength conversion member 4 are located within the opening 91a in a planar view. In a planar view, the opening 91a of the second heat dissipation member 91 may be larger than the outer periphery of the first resin member 51. In other words, the diameter of the opening 91a of the second heat dissipation member 91 may be larger than the outer diameter of the first resin member 51. In a planar view, the opening 91a may be larger than the wavelength conversion member 4. Illumination light from the wavelength conversion member 4 passes through the opening 91a of the second heat dissipation member 91.

The second heat dissipation member 91 may be in partial contact with the first surface 6a and side surfaces of the first heat dissipation member 6, or a highly thermally conductive resin such as thermal grease may be positioned between the second heat dissipation member 91 and the first heat dissipation member 6.

If the light emitting device 1 includes an intermediate member 5, the second heat dissipation member 91 may be in partial contact with the first surface 5a and the side surface 5c of the intermediate member 5. A highly thermally conductive resin such as thermal grease may be located between the second heat dissipation member 91 and the intermediate member 5.

The second heat dissipation member 91 may protrude outward beyond the substrate 21. The portion of the second heat dissipation member 91 that protrudes outward beyond the substrate 21 may be in contact with the first surface 92a of the heat sink 92. Alternatively, a highly thermally conductive resin such as thermal grease may be positioned between the second heat dissipation member 91 and the heat sink 92.

As shown in FIG. 5, the outer periphery of the second heat dissipation member 91 may be partially circular, and notches 91b may be formed at positions corresponding to the corners of the substrate 21. In other words, the second heat dissipation member 91 may have a petal-like shape in a plan view. A second heat dissipation member 91 having such a complex shape may be manufactured using, for example, a predetermined mold. The second heat dissipation member 91 may also be called a sleeve. The external electrode 71b and the external electrode 72b are exposed from the second heat dissipation member 91 at the corresponding notches 91b. Wiring 85 is connected to the external electrode 71b, and wiring 86 is connected to the external electrode 72b.

The thermal conductivity of the second heat dissipation member 91 is higher than that of air. The thermal conductivity of the second heat dissipation member 91 may be higher than that of the wavelength conversion member 4. The second heat dissipation member 91 may be made of, for example, a metal such as aluminum, a ceramic such as alumina, or a resin or rubber. The resin or rubber may contain a highly thermally conductive filler. The highly thermally conductive filler may contain at least one of silver, aluminum, aluminum oxide, and graphene, which have a higher thermal conductivity than the wavelength conversion member 4.

As shown in FIG. 5, the cylindrical body 93 may include a first arc portion 931 and a second arc portion 932. The first arc portion 931 and the second arc portion 932 have shapes obtained by dividing the cylindrical body 93 into two in the circumferential direction. The first arc portion 931 and the second arc portion 932 are joined in the circumferential direction to form the cylindrical body 93. In FIG. 5, the first arc portion 931 and the second arc portion 932 are shown separated from each other. A fixing member such as a locking portion for joining the first arc portion 931 and the second arc portion 932 to each other may be attached to the first arc portion 931 and the second arc portion 932.

The cylindrical body 93 is fixed to the heat sink 92. One peripheral end of the cylindrical body 93 is connected to the first surface 92a of the heat sink 92. The cylindrical body 93 houses the light-emitting device 1. The inner peripheral surface of the cylindrical body 93 is in contact with the outer peripheral surface of the second heat dissipation member 91. The cylindrical body 93 may have a cylindrical shape. The inner peripheral surface of the cylindrical body 93 can press against the outer peripheral surface of the second heat dissipation member 91. This improves the adhesion between the cylindrical body 93 and the second heat dissipation member 91. The higher the adhesion, the easier it is for heat to be transferred from the second heat dissipation member 91 to the cylindrical body 93.

The thermal conductivity of the cylindrical body 93 may be higher than that of air and higher than that of the wavelength conversion member 4. The cylindrical body 93 may be made of a metal such as aluminum.

As shown in FIG. 5, the second heat dissipation member 91 may have four notches 91b. The four notches 91b are formed at equally spaced positions in the circumferential direction, exposing four corners of the substrate 21, respectively. Two diagonally positioned notches 91b expose the external electrodes 71b and 72b, and wiring 85 and wiring 86 are connected to the external electrodes 71b and 72b, respectively. The remaining two notches 91b are not necessarily required, but may provide the technical significance described below.

In plan view, the portion 91c surrounded by two adjacent notches 91b protrudes toward the opposite side (i.e., outward) from the light-emitting element 3. Because many notches 91b are provided, the width of the portion 91c is relatively narrow. When this narrow portion 91c is pressed inward by the cylindrical body 93, the portion 91c is prone to deformation as follows: That is, the circumferential width of the portion 91c increases and the radial width decreases. When the portion 91c is pressed against the inner peripheral surface of the cylindrical body 93 with this deformation, the adhesion between the outer peripheral surface of the portion 91c and the inner peripheral surface of the cylindrical body 93 increases. The above-described elastic deformation is particularly easy when the second heat dissipation member 91 is made of an elastic material such as resin or rubber. To improve adhesion, it is sufficient to form three or more notches 91b, and five or more notches 91b may also be formed.

The cylindrical body 93 has a lead-out opening 93a for leading out the wiring 85 and a lead-out opening 93b for leading out the wiring 86.

An optical system (not shown), such as a lens, may be located inside the cylindrical body 93. The optical system may be positioned alongside the light-emitting device 1 in the thickness direction of the substrate 21. Illumination light from the wavelength conversion member 4 may be emitted to the outside through the optical system. The cylindrical body 93 may also be called a lens barrel.

In the third embodiment, the heat generated by the wavelength conversion member 4 passes through the first heat dissipation member 6 and the second heat dissipation member 91 in this order, and is then transferred to the heat sink 92 and the cylindrical body 93. This further improves the heat dissipation performance of the light emitting device 1. In the example described above, the second heat dissipation member 91 contacts the first surface 6a and the side surface of the first heat dissipation member 6. This allows the second heat dissipation member 91 to contact the first heat dissipation member 6 over a wider area, and to receive heat from the first heat dissipation member 6 over a wider area. This therefore further improves the heat dissipation performance of the light emitting device 1.

In the above example, the tubular body 93 has a cylindrical shape, but this is not necessarily limited to this. The tubular body 93 may also have a polygonal tubular shape. In this case, the outer peripheral surface of the second heat dissipation member 91 may have a polygonal shape that partially follows the inner peripheral surface of the tubular body 93.

Fourth Embodiment
6 is a cross-sectional view schematically illustrating an example of a portion of the configuration of a light emitting device 1 according to the fourth embodiment. The light emitting device 1 according to the fourth embodiment differs from the light emitting device 1 according to the first or second embodiment in the presence or absence of a second resin member 52. The second resin member 52 is located between the first resin member 51 and the first heat dissipation member 6. The thermal conductivity of the second resin member 52 is higher than that of air. The thermal conductivity of the second resin member 52 may be higher than that of the first resin member 51 or may be higher than that of the wavelength conversion member 4. The thermal conductivity of the second resin member 52 may be lower than that of the first heat dissipation member 6.

The second resin member 52 may be a resin containing a highly thermally conductive filler. The highly thermally conductive filler contains at least one of silver, aluminum, aluminum oxide, and graphene, which have a higher thermal conductivity than the wavelength conversion member 4. The resin may be, for example, an epoxy resin or a silicone resin.

As shown in FIG. 6, the second resin member 52 may be in contact with the intermediate member 5, the first heat dissipation member 6, and the reflector 8. If the intermediate member 5 is not provided, the second resin member 52 may be in contact with the wavelength conversion member 4. Referring to FIG. 2, the second resin member 52 may fill the space between the first resin member 51 and the first heat dissipation member 6 at least in the recess 6c. This allows the heat generated by the wavelength conversion member 4 to be effectively transferred to the first heat dissipation member 6 via the intermediate member 5 and the second resin member 52.

If the second resin member 52 is in contact with the first resin member 51, the second resin member 52 is likely to come into contact with a wider area of the intermediate member 5. This allows heat from the intermediate member 5 to be transferred more effectively to the first heat dissipation member 6. On the other hand, if the second resin member 52 is in contact with the reflector 8, the second resin member 52 is likely to come into contact with the entire side surface of the first heat dissipation member 6. This also allows heat from the wavelength conversion member 4 to be transferred more effectively to the first heat dissipation member 6.

The second resin member 52 may be bonded to at least one of the intermediate member 5, the first resin member 51, the first heat dissipation member 6, and the reflector 8. The second resin member 52 can be formed as follows. That is, the second resin member 52 before solidification is applied between the first resin member 51 and the first heat dissipation member 6, and the second resin member 52 before solidification is solidified using a curing agent, heat, or light, thereby forming the second resin member 52. The viscosity of the second resin member 52 before solidification is lower than the viscosity of the first resin member 51 before solidification. This makes it easier for the second resin member 52 to fill the space between the first resin member 51 and the first heat dissipation member 6.

The second resin member 52 may be reflective to the illumination light. For example, a reflective material such as silver, aluminum, or aluminum oxide may be used as the filler of the second resin member 52. The reflectance (maximum value) of the second resin member 52 to the illumination light may be, for example, 50% or more, 60% or more, 70% or more, 80% or more, or 90% or more. This allows the illumination light incident on the second resin member 52 from the wavelength conversion member 4 to be reflected. In the example of Figure 6, the illumination light emitted from the side surface of the wavelength conversion member 4 may pass through the indirect member 5 and enter the second resin member 52. The second resin member 52 reflects the illumination light. This increases the amount of illumination light emitted from the light emitting device 1.

On the other hand, since the illumination light travels into the illumination space from the second resin member 52, which is positioned further outward than the first resin member 51, the emission diameter of the light-emitting device 1 may widen. To reduce this widening of the emission diameter, the second resin member 52 may be absorbing illumination light. The second resin member 52 may be a black resin. For example, graphene or aluminum oxide may be used as the filler for the second resin member 52. The absorption rate (maximum value) of the illumination light by the second resin member 52 may be, for example, 50% or more, 60% or more, 70% or more, 80% or more, or 90% or more. This allows the second resin member 52 to effectively absorb illumination light incident on the second resin member 52 from the wavelength conversion member 4. This reduces the emission diameter of the light-emitting device 1.

Fifth Embodiment
Fig. 7 is a cross-sectional view schematically showing an example of a portion of the configuration of the light-emitting device 1 according to the fifth embodiment. Fig. 8 is a plan view schematically showing an example of a portion of the configuration of the light-emitting device 1 according to the fifth embodiment. The light-emitting device 1 according to the fifth embodiment differs from the light-emitting devices 1 according to the first to fourth embodiments in the presence or absence of an electronic component 35. The electronic component 35 is located between the substrate 2 and the wavelength conversion member 4, and in the example of Fig. 7, it is located between the reflector 8 and the intermediate member 5. Furthermore, the electronic component 35 is located between the first resin member 51 and the first heat dissipation member 6 in a plan view.

The electronic component 35 may be connected to the conductive pattern 7. As shown in FIG. 8, a first end of the electronic component 35 may be connected to the element electrode 71a, and a second end of the electronic component 35 may be connected to the wiring 72c. In this case, the electronic component 35 is connected in parallel to the light-emitting element 3. The electronic component 35 may be, for example, a protective element that protects the light-emitting element 3. As a specific example, the electronic component 35 may be a Zener diode. In this case, the electronic component 35 can protect the light-emitting element 3 from overvoltage or reverse voltage.

As a specific example, the first end of the electronic component 35 may be connected to the arc-shaped end of the element electrode 71a, and the second end of the electronic component 35 may be connected to the wiring 72c near the element electrode 72a. This allows the electronic component 35 to be positioned close to the light-emitting element 3, thereby protecting the light-emitting element 3 with greater precision.

Alternatively, the electronic component 35 may be a light-emitting element (corresponding to an example of a second light-emitting element). The electronic component 35 may be a semiconductor light-emitting element, and more specifically, an LED element. The electronic component 35 may emit light of a wavelength different from the excitation light of the light-emitting element 3. An example of the wavelength may be the same as that of the sixth embodiment described below.

Furthermore, the fourth embodiment may be adopted in the fifth embodiment. The second resin member 52 may cover and adhere to the electronic component 35. In other words, the second resin member 52 may seal the electronic component 35. In this case, the electronic component 35 can be protected from external factors such as moisture. If the electronic component 35 is a light-emitting element, the second resin member 52 is translucent to the light emitted by the electronic component 35.

Sixth Embodiment
9 is a plan view schematically showing a first example of a portion of the configuration of the light emitting device 1 according to the sixth embodiment. The light emitting device 1 according to the sixth embodiment differs from the light emitting devices 1 according to the first to fifth embodiments in terms of the number of light emitting elements 3. The light emitting device 1 according to the sixth embodiment includes a plurality of light emitting elements 3. In the sixth embodiment, the plurality of light emitting elements 3 are surrounded by the first resin member 51 in a planar view. In other words, the plurality of light emitting elements 3 are located within a region surrounded by the inner periphery of the first resin member 51 in a planar view. All of the plurality of light emitting elements 3 may be included within this region, and the plurality of light emitting elements 3 may not protrude from this region.

As shown in FIG. 9, multiple light-emitting elements 3 may be connected in parallel to one another. In the example of FIG. 9, light-emitting elements 3A to 3D are shown as the light-emitting elements 3. Light-emitting elements 3A to 3D are located on element electrodes 72a of the first conductive pattern 71. Light-emitting elements 3A to 3D may be arranged in a matrix in plan view. As in the first to fifth embodiments, each of light-emitting elements 3A to 3D has a second element electrode on the second surface 3b. The second element electrode of each of light-emitting elements 3A to 3D is electrically connected to element electrode 72a.

Each of the light-emitting elements 3A to 3D has a first element electrode on the first surface 3a, as in the first to fifth embodiments. The first element electrode of the light-emitting element 3A is connected to the element electrode 71a of the first conductive pattern 71 via wire 31A, the first element electrode of the light-emitting element 3B is connected to the element electrode 71a via wire 31B, the first element electrode of the light-emitting element 3C is connected to the element electrode 71a via wire 31C, and the first element electrode of the light-emitting element 3D is connected to the element electrode 71a via wire 31D.

FIG. 10 is a plan view schematically illustrating a second example of a portion of the configuration of the light-emitting device 1 according to the sixth embodiment. As shown in FIG. 10, multiple light-emitting elements 3 may be connected in series. In the example of FIG. 10, light-emitting elements 3A to 3D are also shown as the light-emitting elements 3. In the example of FIG. 10, the light-emitting device 1 includes a first conductive pattern 71, a second conductive pattern 72, an element electrode 73, an element electrode 74, and an element electrode 75. The element electrode 72a, the element electrode 73, the element electrode 74, and the element electrode 75 of the second conductive pattern 72 are located within a region surrounded by the inner periphery of the first resin member 51 in a plan view. These may be located on the insulating film 22, or may be arranged in a matrix.

Light-emitting element 3A is located on element electrode 72a, and the second element electrode of light-emitting element 3A is electrically connected to element electrode 72a. Light-emitting element 3B is located on element electrode 73, and the second element electrode of light-emitting element 3B is connected to element electrode 73. Like light-emitting element 3B, light-emitting element 3C is located on element electrode 74, and the second element electrode of light-emitting element 3C is connected to element electrode 74, and light-emitting element 3D is located on element electrode 75, and the second element electrode of light-emitting element 3D is connected to element electrode 75. The first element electrode of light-emitting element 3A is connected to element electrode 73 via wire 31A, the first element electrode of light-emitting element 3B is connected to element electrode 74 via wire 31B, the first element electrode of light-emitting element 3C is connected to element electrode 75 via wire 31C, and the first element electrode of light-emitting element 3D is connected to element electrode 71a via wire 31D.

In Figures 9 and 10, the multiple light-emitting elements 3 may have the same structure. That is, the multiple light-emitting elements 3 may output excitation light in the same wavelength range. Alternatively, at least one of the multiple light-emitting elements 3 may have a structure different from the other light-emitting elements 3. That is, at least one of the light-emitting elements 3 (corresponding to the second light-emitting element) may emit light having a peak wavelength in a wavelength range different from the wavelength range of light emitted by the other light-emitting elements 3 (corresponding to the first light-emitting element). For example, light-emitting element 3D may emit light having a peak wavelength in a wavelength range different from that of light-emitting elements 3A to 3C.

As a specific example, light-emitting elements 3A to 3C emit excitation light with a blue wavelength. Wavelength conversion member 4 contains YAG phosphor particles that emit fluorescence based on the excitation light. A light-emitting element that emits red light can be used for light-emitting element 3D. Light-emitting element 3D may be a semiconductor light-emitting element, such as an LED element. The light emitted by light-emitting element 3D does not need to be significantly converted by wavelength conversion member 4. In other words, light-emitting element 3D may emit light that is less absorbed by wavelength conversion member 4 than the excitation light emitted by light-emitting elements 3A to 3C. The red light from light-emitting element 3D can be emitted to the outside, mainly passing through filler 53 and wavelength conversion member 4.

While white light produced by YAG phosphor particles excited by blue excitation light is primarily lacking in red, the light-emitting element 3D can supplement this with red. In other words, the light-emitting device 1 can emit white light supplemented with red as illumination light. In other words, the color rendering properties of the illumination light can be improved.

Seventh Embodiment
11 is a plan view schematically illustrating an example of a portion of the configuration of a light-emitting device 1 according to the seventh embodiment. The light-emitting device 1 according to the seventh embodiment includes a plurality of light-emitting elements 3. In the seventh embodiment, the plurality of light-emitting elements 3 are surrounded by a first resin member 51 in a planar view. That is, the plurality of light-emitting elements 3 are located within a region surrounded by the inner peripheral edge of the first resin member 51 in a planar view. All of the plurality of light-emitting elements 3 may be included within the region, or the plurality of light-emitting elements 3 may not protrude from the region. In the seventh embodiment, a voltage different from the voltage applied to one of the other light-emitting elements 3 (corresponding to an example of a first light-emitting element) is input to one of the light-emitting elements 3 (corresponding to an example of a second light-emitting element).

As shown in FIG. 11, the light-emitting device 1 further includes a third conductive pattern 77. The third conductive pattern 77 includes an element electrode 77a, an external electrode 77b, and wiring 77c. As shown in FIG. 11, the element electrode 77a may have an arc shape in a plan view and may be adjacent to the element electrode 72a of the second conductive pattern 72 at an interval. The central angle of the element electrode 77a may be less than 180 degrees and may be concentric with the element electrode 71a of the first conductive pattern 71 and the element electrode 72a of the second conductive pattern 72. As shown in FIG. 11, the central angle of the element electrode 71a of the first conductive pattern 71 may also be less than 180 degrees, and the element electrode 71a may be aligned with the element electrode 77a at an interval in the circumferential direction.

In a plan view, the external electrode 77b may be located at a corner of the substrate 21 where the external electrodes 71b and 72b are not provided. The external electrode 71b may have a rectangular shape in a plan view. One end of the wiring 87 is connected to the external electrode 71b.

Wiring 77c electrically connects element electrode 77a and external electrode 77b. Wiring 77c has a strip shape and may extend linearly from element electrode 77a to external electrode 77b. Wiring 72c extends, for example, along a diagonal line of substrate 21. The diameter of element electrode 77a may be larger than the width of wiring 77c, and the diagonal length of external electrode 77b may be larger than the width of wiring 72c.

In the example of FIG. 11, light-emitting elements 3A to 3D are shown as the multiple light-emitting elements 3. As shown in FIG. 11, light-emitting elements 3A to 3D may be positioned on element electrode 72a, and the second element electrodes of light-emitting elements 3A to 3D may be electrically connected to element electrode 72a. Light-emitting elements 3A to 3D may be arranged in a matrix. The first element electrode of light-emitting element 3B (an example of a first light-emitting element) may be connected to element electrode 71a (an example of a first electrode) via wire 31B, and the first element electrode of light-emitting element 3C (an example of a first light-emitting element) may be connected to element electrode 71a via wire 31C. The first element electrode of light-emitting element 3A (an example of a second light-emitting element) may be connected to element electrode 77a (an example of a second electrode) via wire 31A, and the first element electrode of light-emitting element 3D (an example of a second light-emitting element) may be connected to element electrode 77a via wire 31D.

FIG. 12 is a diagram schematically illustrating an example of the electrical configuration of the light-emitting device 1. As shown in FIG. 12, wiring 85 and wiring 86 may be connected to a first power supply 81, and wiring 86 and wiring 87 may be connected to a second power supply 82. Wiring 86 may be grounded. The first power supply 81 and the second power supply 82 may output different voltages. Each of the first power supply 81 and the second power supply 82 may include a switching power supply circuit (not shown). The first power supply 81 and the second power supply 82 may output a variable DC voltage.

The control unit 80 may control the output voltages of the first power supply 81 and the second power supply 82. The control unit 80 is a control circuit and includes, for example, a central processing unit (CPU) and a memory unit. The memory unit includes non-transitory recording media that can be read by the CPU, such as read-only memory (ROM) and random access memory (RAM). The memory unit stores, for example, programs for controlling the first power supply 81 and the second power supply 82. The various functions of the control unit 80 are realized when the CPU executes the programs in the memory unit.

The control unit 80 may control the first power supply 81 using a predetermined first target value. The first target value is a target value for the first power supply 81 regarding voltage, current, or power. The first target value may be a value for causing light-emitting elements 3B and 3C to emit a predetermined amount of light. The control unit 80 may control the second power supply 82 using a predetermined second target value. The second target value is a target value for the second power supply 82 regarding voltage, current, or power. The second target value may be a value for causing light-emitting elements 3A and 3D to emit a predetermined amount of light. Therefore, each of the first power supply 81 and the second power supply 82 can output a voltage or current appropriate for each light-emitting element 3.

Light-emitting elements 3B and 3C emit a first light, and light-emitting elements 3A and 3D emit a second light having a wavelength spectrum different from that of the first light. As a specific example, light-emitting elements 3B and 3C emit purple excitation light, and light-emitting elements 3A and 3D emit blue light.

The wavelength conversion member 4 includes, for example, the red, green, and blue phosphors already described. Figure 13 is a graph showing an example of the wavelength dependence of the absorptance of phosphors. Graph G1 shows the wavelength dependence for the blue phosphor, graph G2 shows the wavelength dependence for the red phosphor, and graph G3 shows the wavelength dependence for the green phosphor. As shown in Figure 13, the wavelength dependence of the blue phosphor is greater than the wavelength dependence of the red and blue phosphors.

The peak wavelength of the excitation light from light-emitting element 3B and light-emitting element 3C can vary from one element to another due to manufacturing variations, etc. Therefore, if the content of blue phosphor in wavelength conversion member 4 is constant, variations between individual light-emitting elements 3 will cause variations in the illumination light from wavelength conversion member 4. In other words, the amount of blue component in the illumination light will fluctuate depending on the individual differences between light-emitting element 3B and light-emitting element 3C.

In the above example, light-emitting elements 3A and 3D emit blue light. At least a portion of this blue light passes through filler 53 and wavelength conversion member 4 and is emitted to the outside. Control unit 80 may control second power supply 82 using a second target value that corresponds to individual variations in light-emitting elements 3B and 3C. This second target value is set in advance, for example, through experiments or simulations. Specifically, control unit 80 controls first power supply 81 and second power supply 82 to cause light-emitting elements 3A to 3D to emit light, and sets a second target value for the output of second power supply 82 so that the evaluation value of the illumination light of light-emitting device 1 falls within a predetermined target range. The evaluation value may include at least one of color temperature and color deviation. The second target value is stored in advance in a storage unit (e.g., a memory) of control unit 80.

Explaining in more general terms, the wavelength conversion member 4 includes a first phosphor 41a that emits a first fluorescence (e.g., blue fluorescence) and a second phosphor 41b that emits a second fluorescence (e.g., red or green fluorescence) (see also Figure 1). The wavelength dependence of the absorption rate of the second phosphor 41b for excitation light is greater than the wavelength dependence of the first phosphor 41a. The light emitting device 1 includes a light emitting element 3 that emits excitation light for the wavelength conversion member 4 and a light emitting element 3 that emits light of the same color as the second fluorescence. Here, "light of the same color" refers to light having a peak wavelength closer to the wavelength of the second fluorescence of the second phosphor 41b than to the wavelength of the first fluorescence of the first phosphor 41a. The light emitting element 3 that emits light of the same color as the second phosphor 41b is powered by a second power source 82, and the light emitting element 3 that emits excitation light is powered by a first power source 81. The control unit 80 controls the second power source 82 using a second target value that corresponds to the wavelength variation of the excitation light. This allows individual variations in the light-emitting elements 3 that emit excitation light to be absorbed, allowing the light-emitting device 1 to emit more appropriate illumination light.

Eighth Embodiment
In the examples of the first to seventh embodiments, the first element electrode and the second element electrode of the light-emitting element 3 are located on the first surface 3 a and the second surface 3 b of the light-emitting element 3, respectively. However, this embodiment is not necessarily limited to this. For example, the first element electrode and the second element electrode may be located on the second surface 3 b of the light-emitting element 3.

FIG. 14 is a cross-sectional view schematically showing a first example of a portion of the configuration of a light-emitting device 1 according to the eighth embodiment. In the example of FIG. 14, the second surface 3b of the light-emitting element 3 is located across the element electrodes 71a and 72a. A first element electrode and a second element electrode are located on the second surface 3b of the light-emitting element 3, with the first element electrode connected to the element electrode 71a and the second element electrode connected to the element electrode 72a. For example, the first element electrode is connected to the element electrode 71a and the second element electrode is connected to the element electrode 72a by an electrode material such as solder.

Alternatively, the first element electrode and the second element electrode may be located on the first surface 3a of the light-emitting element 3. Figure 15 is a cross-sectional view schematically showing a second example of a portion of the configuration of the light-emitting device 1 according to the eighth embodiment. In the example of Figure 15, the light-emitting element 3 is formed on the substrate 21. That is, the second surface 3b of the light-emitting element 3 is in contact with the substrate 21. The insulating film 22 may be formed in the same layer as the light-emitting element 3, or may be adjacent to the light-emitting element 3 in a direction parallel to the first surface of the substrate 21. The insulating film 22 may be in contact with the side surface of the light-emitting element 3 and the substrate 21. In this case, it can be said that the substrate portion 2 on which the light-emitting element 3 is located does not include the insulating film 22.

The conductive pattern 7 is formed on the insulating film 22. In a plan view, the conductive pattern 7 is located in an area that avoids the light-emitting element 3. The first element electrode on the first surface 3a of the light-emitting element 3 is connected to the element electrode 71a of the first conductive pattern 71 via wire 31A, and the second element electrode on the first surface 3a of the light-emitting element 3 is connected to the element electrode 72a of the second conductive pattern 72 via wire 31B.

The light-emitting element 3 can also emit excitation light from the second surface 3b. Therefore, the substrate 21 may be reflective to the excitation light. The reflectance of the substrate 21 to the excitation light may be, for example, 50% or more, 60% or more, 70% or more, 80% or more, 90% or more, or 95% or more. The substrate 21 may be reflective to the illumination light. The reflectance (maximum value) of the substrate 21 to the illumination light may be, for example, 50% or more, 60% or more, 70% or more, 80% or more, 90% or more, or 95% or more. The thermal conductivity of the substrate 21 may be higher than that of the wavelength conversion member 4. The substrate 21 may be made of, for example, aluminum. Miro (registered trademark) material can be used for the substrate 21. Because the substrate 21 reflects at least one of the excitation light and the illumination light in this way, the reflective material 8 may not be provided.

Ninth Embodiment
Fig. 16 is a cross-sectional view schematically showing a first example of the configuration of the light-emitting device 1 according to the ninth embodiment. The light-emitting device 1 according to the first example of the ninth embodiment differs from the light-emitting devices 1 according to the first to eighth embodiments in the presence or absence of a first heat-transfer member 561. Fig. 17 is a perspective view schematically showing an example of the configuration of the intermediate member 5 and the first heat-transfer member 561 according to the first example of the ninth embodiment.

The first heat transfer member 561 is located on the opposite side of the intermediate member 5 from the wavelength conversion member 4 and is in contact with the second surface 5b of the intermediate member 5. The intermediate member 5 is formed, for example, from a transparent ceramic. Examples of _{the transparent ceramic include at least one of YAG (Y3Al5O12), Y2O3 , Sc2O3 , Lu2O3 , and sapphire} . The thermal conductivity of these transparent ceramics at room temperature is more than 10 times higher than that of glass at _room temperature (approximately 1.1 W/m·K). In particular, the thermal conductivity of sapphire is approximately 41 W/m·K, approximately 40 times higher than that of glass. Therefore, using sapphire as the material for the intermediate member 5 allows for more effective transfer of heat from the wavelength conversion member 4.

The thermal conductivity of the first heat transfer member 561 is higher than that of the wavelength conversion member 4 and is also higher than that of the indirect member 5. The thermal conductivity of the first heat transfer member 561 may be more than twice, or even more than five times, that of the indirect member 5. On the other hand, the transmittance of the first heat transfer member 561 for excitation light may be lower than that of the indirect member 5. The transmittance of the first heat transfer member 561 for excitation light may be, for example, 10% or less, 5% or less, 2% or less, or 1% or less. The transmittance (maximum value) of the first heat transfer member 561 for illumination light may also be, for example, 10% or less, 5% or less, 2% or less, or 1% or less. Because the transmittance of the first heat transfer member 561 may be low, the freedom in selecting the material for the first heat transfer member 561 can be improved. Therefore, a material with higher thermal conductivity can be used for the first heat transfer member 561. For example, metal may be used as the material of the first heat transfer member 561. Specific examples of materials that may be used for the first heat transfer member 561 include silver, copper, gold, aluminum, zinc, chromium, nickel, and tin, or an alloy containing at least one of these.

As shown in Figures 16 and 17, the first heat transfer member 561 may have a plate-like or sheet-like shape. The first heat transfer member 561 includes a first portion 571 and a second portion 572. The first portion 571 is the portion of the first heat transfer member 561 that faces the first heat dissipation member 6 in the thickness direction of the substrate 21. In other words, the first portion 571 is the portion that overlaps with the first heat dissipation member 6 in a planar view.

The second portion 572 is a portion of the first heat transfer member 561 that does not face the first heat dissipation member 6 in the thickness direction of the substrate 21. In other words, the second portion 572 is a portion that does not overlap the first heat dissipation member 6 in a planar view. The second portion 572 is connected to the first portion 571. In other words, the second portion 572 is continuous with the first portion 571. The second portion 572 is positioned in a state that protrudes from the first heat dissipation member 6 in a planar view. As shown in FIG. 16 , at least a portion of the second portion 572 is positioned closer to the first resin member 51 than the first heat dissipation member 6.

As shown in FIG. 16, the first heat transfer member 561 may face both the heat dissipation member 61 and the heat dissipation member 62. That is, the first heat transfer member 561 may have, as the first portion 571, a portion 5711 facing the heat dissipation member 61 and a portion 5712 facing the heat dissipation member 62. The second portion 572 may be located between portions 5711 and 5712.

The first heat transfer member 561 has a first opening 56a in a region facing at least a portion of the wavelength conversion member 4 in the thickness direction of the substrate 21. In other words, the first heat transfer member 561 is not located in this region. As shown in Figures 16 and 17, the first opening 56a is formed in the second portion 572. The first opening 56a may be surrounded by the second portion 572. As shown in Figure 17, the first opening 56a may have a circular shape in a planar view. The first opening 56a passes through the second portion 572. This first opening 56a is an opening that allows excitation light from the light-emitting element 3 to pass through to the wavelength conversion member 4 side.

The first heat transfer member 561 may be in contact with the entire second surface 5b of the intermediate member 5 except for the first opening 56a. The first heat transfer member 561 may be in contact with the second surface 5b of the intermediate member 5 in an unbonded state. For example, the first heat transfer member 561 may be a metal plate and arranged in a detachable state. Alternatively, the first heat transfer member 561 may be bonded to the second surface 5b of the intermediate member 5. When the first heat transfer member 561 is made of a metal, the first heat transfer member 561 may be formed on the second surface 5b of the intermediate member 5 by, for example, plating, spraying, or coating. When the first heat transfer member 561 is formed by plating, for example, the first heat transfer member 561 can be formed by vacuum deposition, sputtering, CVD (chemical vapor deposition), electroless plating, or the like using the material of the first heat transfer member 561 as a raw material, with the area of the intermediate member 5 other than the area where the first heat transfer member 561 will be formed masked to form the plated portion before placing the intermediate member 5 on the light emitting device 1. Alternatively, electrolytic plating may be performed on top of the first heat transfer member 561. In this case, the first heat transfer member 561 can be easily formed thicker, allowing for more effective heat transfer from the wavelength conversion member 4. Alternatively, the first heat transfer member 561 can be formed by forming a metal film for the first heat transfer member 561 on the entire surface of the intermediate member 5 alone by vacuum deposition, sputtering, CVD (chemical vapor deposition), or electroless plating, and then irradiating the metal film with laser light at the portions where the first opening 56a and the wavelength conversion member 4 will be formed to remove a portion of the metal film. In this case, the first heat transfer member 561 can be formed without a mask, and electrolytic plating may be performed on top of it in the same manner. Laser removal may also be performed after electrolytic plating. In this case, the first heat transfer member 561 may be a heat transfer film formed on the second surface 5b of the intermediate member 5.

Alternatively, the material of the first heat transfer member 561 may be an organic resin such as epoxy resin. Even in this case, the first heat transfer member 561 may be in contact with the second surface 5b of the intermediate member 5 in an unbonded state, or may be bonded to the second surface 5b of the intermediate member 5. The first heat transfer member 561 may be formed on the second surface 5b of the intermediate member 5 by, for example, painting. In this case, the first heat transfer member 561 may also be a heat transfer film.

In this light-emitting device 1, excitation light from the light-emitting element 3 enters the indirect member 5 through the area surrounded by the first resin member 51 and the first opening 56a. The excitation light then passes through the indirect member 5 and enters the wavelength conversion member 4. The wavelength conversion member 4 absorbs at least a portion of the excitation light and emits illumination light (i.e., fluorescent light) and heat.

A portion of the heat generated in the wavelength conversion member 4 is transferred to the second portion 572 of the first heat transfer member 561 via the interior of the intermediate member 5. This heat is transferred from the second portion 572 to the first portion 571 and then to the first heat dissipation member 6. Because the thermal conductivity of the first heat transfer member 561 is higher than that of the intermediate member 5, the heat generated in the wavelength conversion member 4 can be transferred more effectively to the first heat dissipation member 6. In other words, heat from a portion of the intermediate member 5 that is far from the first heat dissipation member 6 is also transferred to the first heat dissipation member 6 via the highly thermally conductive first heat transfer member 561. For example, heat from a portion of the intermediate member 5 near the first resin member 51 is transferred to the first heat dissipation member 6 via the first heat transfer member 561. This further improves the heat dissipation performance of the light emitting device 1. This further mitigates the temperature rise in the wavelength conversion member 4.

Finally, this can mitigate the temperature rise of the intermediate member 5 and reduce variations in the temperature distribution of the intermediate member 5. This can reduce the possibility of peeling between the wavelength conversion member 4 and the intermediate member 5 due to thermal expansion. Furthermore, if the intermediate member 5 is made of sapphire, a sudden change in temperature from high to low may cause cracks in the sapphire. For example, when the light emitting device 1 is used in a low-temperature environment, the temperature of the light emitting device 1 may drop suddenly. Cracks are more likely to occur the greater the temperature change. In this embodiment, the temperature rise of the intermediate member 5 is also mitigated, so even if a temperature drop occurs, the temperature change is relatively small, reducing the possibility of cracks occurring. In other words, the reliability of the light emitting device 1 can also be improved.

The thermal conductivity of transparent ceramics can have temperature dependence, decreasing as the temperature increases. Figure 18 is a graph schematically illustrating an example of the temperature dependence of the thermal conductivity of sapphire. As shown in Figure 18, the thermal conductivity of sapphire is approximately 41 W/mK at room temperature, but decreases to approximately 20 W/mK at 200 degrees Celsius. Therefore, if a transparent material with such temperature dependence is used for the intermediate member 5, the thermal conductivity of the intermediate member 5 will decrease due to the temperature increase associated with light emission from the wavelength conversion member 4. However, in the ninth embodiment, the first heat transfer member 561 is provided, thereby sufficiently improving the heat dissipation of the light emitting device 1 even in relatively high-temperature regions. For example, the thermal conductivity of the first heat transfer member 561 at 200 degrees Celsius may be higher than the thermal conductivity of the intermediate member 5 at 25 degrees Celsius. This allows the heat dissipation of the light emitting device 1 to be sufficiently improved in high-temperature regions. The thermal conductivity of the first heat transfer member 561 may have temperature dependency, decreasing as the temperature increases, but the decrease in thermal conductivity with respect to the amount of change in temperature may be smaller than the decrease in thermal conductivity of the intermediate member 5 with respect to that amount of change. This also allows the heat dissipation performance of the light emitting device 1 to be sufficiently improved in high-temperature regions.

Furthermore, since the first heat transfer member 561 can improve the heat dissipation performance of the light emitting device 1, the intermediate member 5 can be made even smaller. For example, the intermediate member 5 can be made thinner, or the diameter of the intermediate member 5 can be reduced. Since transparent ceramics (especially sapphire) are expensive, this can reduce manufacturing costs.

If the first heat transfer member 561 is bonded to the second surface 5b of the intermediate member 5, the gap between the first heat transfer member 561 and the intermediate member 5 can be reduced. This reduces the thermal resistance between the intermediate member 5 and the first heat transfer member 561. Therefore, heat can be more effectively transferred from the intermediate member 5 to the first heat transfer member 561. If the first heat transfer member 561 is in contact with the entire second surface 5b of the intermediate member 5 except for the first opening 56a, heat can be even more effectively transferred from the intermediate member 5 to the first heat dissipation member 6.

Next, an example of the positional relationship between the first opening 56a of the first heat transfer member 561 and the first resin member 51 will be described. Figure 19 is a diagram schematically showing an example of the positional relationship between the first opening 56a and the first resin member 51. As shown in Figure 19, in a plan view, the outline of the first opening 56a may be located outside the inner peripheral edge 51a of the first resin member 51. In other words, the outline of the first opening 56a may surround the inner peripheral edge 51a of the first resin member 51. The area of the first opening 56a may be larger than the area surrounded by the inner peripheral edge 51a of the first resin member 51. This allows more excitation light from the light-emitting element 3 to be incident on the wavelength conversion member 4.

As shown in FIG. 19, the outline of the first opening 56a may be located between the inner peripheral edge 51a and the outer peripheral edge 51b of the first resin member 51. Because the outline of this first opening 56a is formed by the second portion 572 of the first heat transfer member 561, the second portion 572 can be located near the excitation light incidence area of the wavelength conversion member 4 in a planar view. Therefore, the second portion 572 of the first heat transfer member 561 can be located near the heat-generating portion of the wavelength conversion member 4. Therefore, the first heat transfer member 561 can effectively transfer heat generated at the heat-generating portion to the first heat dissipation member 6.

Alternatively, the outline of the first opening 56a may be located outside the outer peripheral edge 51b of the first resin member 51. Even in this case, the presence of the second portion 572 of the first heat transfer member 561 makes it possible to improve the heat dissipation properties of the light emitting device 1.

Figure 20 is a cross-sectional view that schematically shows a second example of the configuration of the light-emitting device 1 according to the ninth embodiment. The light-emitting device 1 according to the second example of the ninth embodiment differs from the light-emitting device 1 according to the first example of the ninth embodiment in the presence or absence of the second heat-transfer member 562. Figure 21 is a perspective view that schematically shows an example of the configuration of the wavelength conversion member 4, the intermediate member 5, the first heat-transfer member 561, and the second heat-transfer member 562 according to the second example of the ninth embodiment.

The second heat transfer member 562 contacts the intermediate member 5 from the side opposite to the first heat transfer member 561. In other words, the second heat transfer member 562 contacts the first surface 5a of the intermediate member 5. The thermal conductivity of the second heat transfer member 562 is higher than that of the wavelength conversion member 4, and is also higher than that of the intermediate member 5. The thermal conductivity of the second heat transfer member 562 may be at least twice, or may be at least five times, the thermal conductivity of the intermediate member 5.

On the other hand, the transmittance of the second heat transfer member 562 for at least one of the excitation light and the illumination light may be lower than the transmittance of the intermediate member 5. The transmittance of the second heat transfer member 562 for at least one of the excitation light and the illumination light may be, for example, 10% or less, 5% or less, 2% or less, or 1% or less. Since the transmittance of the second heat transfer member 562 may be low, the degree of freedom in selecting the material of the second heat transfer member 562 can be improved. Therefore, a material with higher thermal conductivity can be used for the second heat transfer member 562. Any of the materials exemplified above as the material of the first heat transfer member 561 can be used as the material of the second heat transfer member 562. The second heat transfer member 562 may be made of the same material as the first heat transfer member 561.

The second heat transfer member 562 may be adjacent to the wavelength conversion member 4 in a plan view. As shown in Figures 20 and 21, the second heat transfer member 562 may have a second opening 56b. The outline of the second opening 56b may surround the wavelength conversion member 4. In other words, the wavelength conversion member 4 may be located inside the second opening 56b. In this case, the inner surface of the second heat transfer member 562 that forms the second opening 56b faces the side surface of the wavelength conversion member 4. In this way, the second heat transfer member 562 does not face the emission surface of the wavelength conversion member 4, and therefore does not substantially impede the emission of illumination light from the wavelength conversion member 4.

The second heat transfer member 562 may have a plate or sheet shape. The thickness of the second heat transfer member 562 may be equal to or less than the thickness of the wavelength conversion member 4. In other words, the surface of the second heat transfer member 562 opposite the intermediate member 5 may be flush with the emission surface of the wavelength conversion member 4 opposite the intermediate member 5, or may be located closer to the intermediate member 5 than the emission surface. This makes it possible to prevent illumination light emitted from the emission surface of the wavelength conversion member 4 from entering the second heat transfer member 562.

As described above, in the second example of the ninth embodiment, the light emitting device 1 includes the second heat transfer member 562. The second heat transfer member 562 receives heat generated in the wavelength conversion member 4, for example, via the intermediate member 5. The second heat transfer member 562 can dissipate heat to the outside, further improving the heat dissipation performance of the light emitting device 1.

The second heat transfer member 562 may be in contact with the first surface 5a of the indirect member 5 in an unbonded state. Alternatively, the second heat transfer member 562 may be bonded to the first surface 5a of the indirect member 5. The second heat transfer member 562 may be formed on the first surface 5a by, for example, plating, spraying, or coating. The formation method is the same as that of the first heat transfer member 561, and the second heat transfer member 562 may be formed at the same time as the first heat transfer member 561. In this case, plating may be performed while masking areas of the indirect member 5 other than those where the first heat transfer member 561 and the second heat transfer member 562 are bonded, or the entire surface of the indirect member 5 may be plated and then removed by irradiating the relevant areas of the metal film with laser light. The second heat transfer member 562 can also be considered a heat transfer film formed on the first surface 5a of the indirect member 5. If the second heat transfer member 562 is bonded to the first surface 5a of the indirect member 5, the gap between the second heat transfer member 562 and the first surface 5a of the indirect member 5 can be reduced. This allows heat to be transferred more effectively from the intermediate member 5 to the second heat transfer member 562.

The second heat transfer member 562 may be in contact with the entire first surface 5a of the intermediate member 5 except for the second opening 56b. This allows heat to be more effectively transferred from the intermediate member 5 to the second heat transfer member 562, and the second heat transfer member 562 can more effectively dissipate heat.

A portion of the illumination light (i.e., fluorescence) emitted by the wavelength conversion member 4 may pass through the indirect member 5 and be reflected by the first heat transfer member 561. The reflectance (maximum value) of the first heat transfer member 561 for the illumination light may be, for example, 50% or more, 60% or more, 70% or more, 80% or more, or 90% or more. The reflected illumination light may then pass through the indirect member 5 again and be incident on the second heat transfer member 562. As described above, the transmittance of the second heat transfer member 562 for the illumination light may be lower than the transmittance of the indirect member 5 for the illumination light. In this case, the illumination light cannot pass through the second heat transfer member 562 very much. This reduces the illumination light emitted into the illumination space from areas other than the emission surface of the wavelength conversion member 4. This allows the light emitting device 1 to emit higher-definition illumination light.

A portion of the excitation light reflected by the wavelength conversion member 4 may also be reflected by the first heat transfer member 561 and enter the second heat transfer member 562. The transmittance of the second heat transfer member 562 for excitation light may be lower than the transmittance of the indirect member 5 for excitation light. The transmittance of the second heat transfer member 562 for excitation light may be, for example, 10% or less, 5% or less, 2% or less, or 1% or less. In this case, the excitation light is not able to pass through the second heat transfer member 562 very much. This makes it possible to reduce the excitation light emitted into the illumination space from areas other than the wavelength conversion member 4. This allows the light emitting device 1 to emit illumination light with higher definition.

Figure 22 is a cross-sectional view schematically illustrating a third example of the configuration of the light-emitting device 1 according to the ninth embodiment. The light-emitting device 1 according to the third example of the ninth embodiment differs from the light-emitting device 1 according to the second example of the ninth embodiment in the presence or absence of a third heat transfer member 563.

The third heat transfer member 563 connects the periphery of the first heat transfer member 561 and the periphery of the second heat transfer member 562. The third heat transfer member 563 may be connected to the periphery of the first heat transfer member 561 around its entire circumference, or may be connected to the periphery of the second heat transfer member 562 around its entire circumference. The third heat transfer member 563 may be in contact with the side surface 5c of the intermediate member 5, and as an example, may be in contact with the side surface 5c of the intermediate member 5 around its entire circumference.

The thermal conductivity of the third heat transfer member 563 is higher than that of the wavelength conversion member 4 and also higher than that of the intermediate member 5. The thermal conductivity of the third heat transfer member 563 may be at least twice, or even five times, that of the intermediate member 5. On the other hand, the transmittance of the third heat transfer member 563 for at least one of the illumination light and the excitation light may be lower than that of the intermediate member 5. The transmittance of the third heat transfer member 563 for at least one of the illumination light and the excitation light may be, for example, 10% or less, 5% or less, 2% or less, or 1% or less. Since the transmittance of the third heat transfer member 563 may be low, the freedom in selecting the material for the third heat transfer member 563 can be improved. Therefore, a material with higher thermal conductivity can be used for the third heat transfer member 563. Any of the materials listed above as examples of the material for the first heat transfer member 561 can be used for the third heat transfer member 563. The third heat transfer member 563 may be made of the same material as the first heat transfer member 561 and the second heat transfer member 562.

As described above, in the third example of the ninth embodiment, the light-emitting device 1 includes the third heat-transfer member 563. Therefore, heat transferred from the intermediate member 5 to the second heat-transfer member 562 can be transferred to the first heat-dissipation member 6 via the third heat-transfer member 563 and the first heat-transfer member 561 in this order. This further improves the heat dissipation performance of the light-emitting device 1.

If the third heat transfer member 563 is in contact with the side surface 5c of the intermediate member 5, heat is transferred from the side surface 5c of the intermediate member 5 through the third heat transfer member 563 and the first heat transfer member 561 to the first heat dissipation member 6. This further improves the heat dissipation performance of the light emitting device 1. The third heat transfer member 563 may be in contact with the side surface 5c of the intermediate member 5 in an unbonded state. Alternatively, the third heat transfer member 563 may be bonded to the side surface 5c of the intermediate member 5. This further improves the heat dissipation performance of the light emitting device 1.

If the third heat transfer member 563 is made of the same material as the first heat transfer member 561 and the second heat transfer member 562, the first heat transfer member 561, the second heat transfer member 562, and the third heat transfer member 563 can be integrally formed on the indirect member 5 in the same process. For example, these can be formed integrally on the indirect member 5 by plating, spraying, or coating. This reduces the cost of the indirect member 5, the first heat transfer member 561, the second heat transfer member 562, and the third heat transfer member 563. In this case, at least the portion of the indirect member 5 on which the wavelength conversion member 4 is placed and the portion that will become the first opening 56a can be masked and plated, or the entire surface of the indirect member 5 can be plated and then laser light irradiated onto the relevant portions of the metal film to remove them.

A portion of the illumination light (i.e., fluorescent light) emitted by the wavelength conversion member 4 may pass through the intermediate member 5 and be reflected by the first heat transfer member 561. The reflected fluorescent light may then pass through the intermediate member 5 again and be reflected by the second heat transfer member 562. The reflectance (maximum value) of each of the first heat transfer member 561 and the second heat transfer member 562 for fluorescent light may be, for example, 50% or more, 60% or more, 70% or more, 80% or more, or 90% or more. In this case, the fluorescent light travels through the intermediate member 5 toward the side surface 5c while repeatedly being reflected by the first heat transfer member 561 and the second heat transfer member 562. Figure 23 is a diagram schematically illustrating an example of how fluorescent light travels inside the intermediate member 5. In the example of Figure 23, the fluorescent light is schematically indicated by an arrow. As the fluorescent light travels through the intermediate member 5 toward the side surface 5c, it enters the third heat transfer member 563.

The transmittance (maximum value) of the third heat transfer member 563 for illumination light (i.e., fluorescent light) may be lower than the transmittance (maximum value) of the indirect member 5 for illumination light. The transmittance of the third heat transfer member 563 for illumination light may be, for example, 10% or less, 5% or less, 2% or less, or 1% or less. In this case, fluorescent light does not pass through the third heat transfer member 563 very well. This makes it possible to reduce the amount of fluorescent light emitted into the illumination space from the side surface 5c of the indirect member 5. This allows the light emitting device 1 to emit illumination light with higher definition.

The reflectance (maximum value) of the third heat transfer member 563 for fluorescent light may be, for example, 50% or more, 60% or more, 70% or more, 80% or more, or 90% or more. In this case, a portion of the fluorescent light reflected by the third heat transfer member 563 may be emitted again into the illumination space through the wavelength conversion member 4. This allows the light emitting device 1 to emit illumination light with higher brightness.

The reflectance of each of the first heat transfer member 561 and the second heat transfer member 562 for the excitation light may be 50% or more, 60% or more, 70% or more, 80% or more, or 90% or more. In this case, the excitation light, like fluorescent light, travels inside the indirect member 5 toward the side surface 5c. The transmittance of the third heat transfer member 563 for the excitation light may be lower than the transmittance of the indirect member 5 for the excitation light. The transmittance of the third heat transfer member 563 for the excitation light may be, for example, 10% or less, 5% or less, 2% or less, or 1% or less. In this case, the excitation light is not able to pass through the third heat transfer member 563 very much. This makes it possible to reduce the excitation light emitted into the illumination space from the side surface 5c of the indirect member 5. This allows the light-emitting device 1 to emit higher-definition illumination light.

The reflectivity of the third heat transfer member 563 with respect to the excitation light may be, for example, 50% or more, 60% or more, 70% or more, 80% or more, or 90% or more. In this case, a portion of the excitation light reflected by the third heat transfer member 563 is incident again on the wavelength conversion member 4. This improves the brightness of the illumination light emitted by the wavelength conversion member 4. This allows the light emitting device 1 to emit illumination light with higher brightness.

In the above example, the light emitting device 1 includes the first resin member 51. However, in the ninth embodiment, the light emitting device 1 may not include the first resin member 51. Figure 24 is a cross-sectional view schematically showing a fourth example of the configuration of the light emitting device 1 according to the ninth embodiment. In the example of Figure 24, the light emitting device 1 does not include the first resin member 51. The first heat dissipation member 6 may be separated from the light emitting element 3 in a planar view. The first heat dissipation member 6 may also be separated from the conductive pattern 7. Therefore, even if the first heat dissipation member 6 is conductive, it is easy to ensure insulation between the first heat dissipation member 6 and each of the light emitting element 3 and the conductive pattern 7. On the other hand, the area of the portion of the intermediate member 5 that does not face the first heat dissipation member 6 is large. In the ninth embodiment, the second portion 572 of the first heat transfer member 561 contacts at least a portion of this portion, and further, the first portion 571 continuous with the second portion 572 faces the first heat dissipation member 6. As a result, heat from this portion of the intermediate member 5 is transferred to the first heat dissipation member 6 through the highly thermally conductive first heat transfer member 561. This also improves the heat dissipation performance of the light-emitting device 1 according to the fourth example of the ninth embodiment.

In a structure in which the light emitting device 1 does not include the first resin member 51, the first opening 56a of the first heat transfer member 561 can define the incident area of the wavelength conversion member 4. The thickness of the first heat transfer member 561 may be smaller than the thickness of the first heat dissipation member 6. Because the first heat transfer member 561 is thin, the first opening 56a can be formed in the first heat transfer member 561 with high shape precision. This allows the light emitting device 1 to emit illumination light with a more precise emission diameter.

The first heat dissipation member 6 may have an annular shape surrounding the light-emitting element 3 in a plan view. The filler 53 may fill the space inside the annular first heat dissipation member 6. In this structure, the first heat dissipation member 6 functions as a dam material. The first heat dissipation member 6 may surround the element electrodes 71a and 72a in a plan view. The wiring 71c and wiring 72c may pass through the substrate portion 2, unlike the example described above.

Tenth Embodiment
Fig. 25 is a cross-sectional view schematically showing a first example of the configuration of the light-emitting device 1 according to the tenth embodiment. Fig. 26 is a plan view schematically showing a first example of the configuration of the light-emitting device 1 according to the tenth embodiment. The light-emitting device 1 according to the first example of the tenth embodiment differs from the light-emitting devices 1 according to the first to ninth embodiments in the presence or absence of a pressing portion 65. The light-emitting device 1 may include a first heat-transfer member 561, a second heat-transfer member 562, and a third heat-transfer member 563, as in the ninth embodiment.

The pressing portion 65 presses the indirect member 5 toward the first heat dissipation member 6. This reduces the gap between the indirect member 5 and the first heat dissipation member 6. The factors that cause the gap between the indirect member 5 and the first heat dissipation member 6 will be described in detail later. In the tenth embodiment, the gap between the indirect member 5 and the first heat dissipation member 6 is reduced, thereby reducing the thermal resistance between the indirect member 5 and the first heat dissipation member 6. This allows heat to be transferred more effectively from the indirect member 5 to the first heat dissipation member 6.

25 and 26, the pressing portion 65 may include a pressing member 66 and a fastening member 67. The pressing member 66 includes a third portion 661 and a fourth portion 662. The third portion 661 is located on the opposite side of the intermediate member 5 from the first heat dissipation member 6. In other words, the third portion 661 is located on the first surface 5a side of the intermediate member 5. The third portion 661 faces the intermediate member 5 in the thickness direction of the substrate 21. The third portion 661 may be in contact with the first surface 5a of the intermediate member 5. Alternatively, when the second heat transfer member 562 is located on the first surface 5a of the intermediate member 5, the third portion 661 may be in contact with the second heat transfer member 562. The fourth portion 662 is located outside the intermediate member 5 in a planar view (see FIG. 26). The fourth portion 662 does not face the intermediate member 5 in the thickness direction of the substrate 21, but faces the first heat dissipation member 6. The fourth portion 662 is connected to the third portion 661. In other words, the fourth portion 662 is continuous with the third portion 661 and is positioned in a state where it protrudes from the third portion 661 to the outside of the intermediate member 5. A fastening through hole 65a is formed in the fourth portion 662. The through hole 65a penetrates the fourth portion 662 in the thickness direction of the substrate 21.

The fastening member 67 fastens the pressing member 66 to the first heat dissipation member 6 through a through hole 65a formed in the fourth portion 662. As a specific example, the fastening member 67 may include a bolt or a screw. That is, the fastening member 67 may include a screw head 671 and a threaded portion 672 (see Figure 25). The fastening member 67 is inserted into the through hole 65a of the fourth portion 662. The inner diameter of the through hole 65a is larger than the diameter of the threaded portion 672. As shown in Figure 25, a threaded hole may be formed in the first heat dissipation member 6 at a position opposite the through hole 65a. The threaded portion 672 is coupled to the first heat dissipation member 6 by screw action, and the screw head 671 of the fastening member 67 presses the pressing member 66 toward the first heat dissipation member 6. When the pressing member 66 is pressed toward the first heat dissipation member 6, the third portion 661 of the pressing member 66 presses the intermediate member 5 toward the first heat dissipation member 6.

In the example of Figure 25, a screw hole is formed in the first heat dissipation member 6, but this is not necessarily limited to this. A screw hole may also be formed in the substrate 21, and the threaded portion 672 may be connected to the substrate 21 by a screw action. Alternatively, the fastening member 67 may include a nut. The fastening member 67 may also fasten the pressing member 66 to the structure from the first heat dissipation member 6 to the substrate 21 by co-tightening.

As shown in Figures 25 and 26, the light emitting device 1 may include multiple pressing portions 65. As a specific example, the light emitting device 1 may include two pressing portions 65. Hereinafter, the two pressing portions 65 will also be referred to as the first pressing portion 651 and the second pressing portion 652, respectively. The pressing member 66 of the first pressing portion 651 may be positioned opposite the heat dissipation member 61 in the thickness direction of the substrate 21, and the pressing member 66 of the second pressing portion 652 may be positioned opposite the heat dissipation member 62 in the thickness direction of the substrate 21.

The pressing member 66 of the first pressing portion 651 may face the first corner 551 of the intermediate member 5 in the thickness direction of the substrate 21. The pressing member 66 of the second pressing portion 652 may face the second corner 552 diagonally opposite the first corner 551 of the intermediate member 5 in the thickness direction of the substrate 21. The first corner 551 of the intermediate member 5 may face the heat dissipation member 61 in the thickness direction of the substrate 21, and the second corner 552 of the intermediate member 5 may face the heat dissipation member 62 in the thickness direction of the substrate 21. As shown in FIG. 26 , each pressing member 66 may have a triangular shape in a plan view. Specifically, each pressing member 66 may have a right-angled triangular shape. Each pressing member 66 may be positioned such that the two sides other than the hypotenuse are aligned along the respective sides of the intermediate member 5.

Each pressing member 66 may have multiple through holes 65a formed therein. As a specific example, each pressing member 66 may have two through holes 65a formed therein. A first corner 551 of the intermediate member 5 may be located between the two through holes 65a of the first pressing portion 651, and a second corner 552 of the intermediate member 5 may be located between the two through holes 65a of the second pressing portion 652. As shown in FIG. 26 , each through hole 65a may be located near an acute corner of the pressing member 66. With this structure in which the corner of the intermediate member 5 is located between two through holes 65a, the pressing member 66 can more effectively press the corner of the intermediate member 5 toward the first heat dissipation member 6 by fastening the fastening member 67.

As described above, according to the tenth embodiment, the pressing portion 65 presses the intermediate member 5 toward the first heat dissipation member 6. This reduces the thermal resistance between the intermediate member 5 and the first heat dissipation member 6.

27 is a cross-sectional view schematically illustrating a first specific example of the configuration of a light-emitting device 1 in which a pressing portion 65 is not disposed. In this first specific example, a portion of the filler 53 is interposed between the first resin member 51 and the intermediate member 5. This is because the amount of filler 53 may be larger than the space inside the first resin member 51 within the manufacturing clearance range. By using a larger amount of filler 53 in this way, the filler 53 can be more securely bonded to the intermediate member 5. On the other hand, a gap may occur between the intermediate member 5 and the first heat dissipation member 6. Although the gap is exaggerated in the example of FIG. 27, it is actually smaller. With this structure, the end of the intermediate member 5 is open as a free end, so even if the light-emitting device 1 is subjected to an external impact, the impact can be dissipated from the intermediate member 5. Furthermore, even if there is a difference in the thermal expansion coefficient between the intermediate member 5 and the first heat dissipation member 6, thermal stress applied from the first heat dissipation member 6 to the intermediate member 5 can be almost completely avoided. Furthermore, when the second resin member 52 is not present, thermal stress caused by bonding between the second resin member 52 and the intermediate member 5 does not occur. However, this gap increases the thermal resistance between the intermediate member 5 and the first heat dissipation member 6.

Figure 28 is a cross-sectional view schematically showing a second specific example of the configuration of a light-emitting device 1 in which a pressing portion 65 is not arranged. In this second specific example, a portion of the first resin member 51 is located closer to the wavelength conversion member 4 than the first surface 6a of the first heat dissipation member 6. This is because a relatively large amount of the first resin member 51 may be used within the manufacturing clearance range. In this case, too, a gap is created between the intermediate member 5 and the first heat dissipation member 6. In the example of Figure 28, this gap is also exaggerated. With the structure of Figure 28, the light-emitting device 1 can also dissipate impacts from the intermediate member 5, reducing thermal stress generated in the intermediate member 5. However, this gap increases thermal resistance.

29 is a cross-sectional view schematically illustrating a third specific example of the configuration of a light-emitting device 1 in which a pressing portion 65 is not disposed. In the third specific example, a portion of the second resin member 52 is interposed between the intermediate member 5 and the first heat dissipation member 6. This is because a relatively large amount of the second resin member 52 may be used within the manufacturing clearance range. By using a larger amount of the second resin member 52 in this manner, the second resin member 52 can be more securely bonded to the intermediate member 5. On the other hand, since a portion of the second resin member 52, which has a lower thermal conductivity than the first heat dissipation member 6, is interposed between the intermediate member 5 and the first heat dissipation member 6, the thermal resistance between the intermediate member 5 and the first heat dissipation member 6 becomes relatively large. In the example of FIG. 29, the second resin member 52 is interposed between the intermediate member 5 and the first heat dissipation member 6, resulting in a gap between the intermediate member 5 and the first heat dissipation member 6. In the example of FIG. 29, the gap is also exaggerated. This structure reduces the thermal resistance in the path from the intermediate member 5 to the first heat dissipation member 6, thereby improving the heat dissipation performance of the optical light-emitting device 1 compared to the structures shown in Figures 27 and 28. Furthermore, the intermediate member 5 is less likely to peel off. However, this gap increases the thermal resistance.

In contrast, in the tenth embodiment, the pressing portion 65 presses the indirect member 5 toward the first heat dissipation member 6. This makes it possible to reduce the gap between the indirect member 5 and the first heat dissipation member 6, for example. Alternatively, it is possible to reduce the thickness of the second resin member 52 between the indirect member 5 and the first heat dissipation member 6. Therefore, it is possible to reduce the thermal resistance between the indirect member 5 and the first heat dissipation member 6.

The pressing portion 65 may be attached to the first heat dissipation member 6 at the timing described below during the manufacture of the light emitting device 1. First, the filling liquid, which is the filler material 53 before solidification, is applied to the space inside the solidified first resin member 51, and then the intermediate member 5 with the wavelength conversion member 4 attached is placed on top of the first resin member 51 and the first heat dissipation member 6. Next, the pressing portion 65 is attached to the intermediate member 5 and the first heat dissipation member 6. This presses the intermediate member 5 toward the first heat dissipation member 6, reducing the gap between the intermediate member 5 and the first heat dissipation member 6. At this time, the filling liquid may also be pressed by the intermediate member 5. This pressure causes the filling liquid to spread within the space inside the first resin member 51. This reduces the void within the space. Furthermore, the filling material may overflow between the intermediate member 5 and the first resin member 51. Next, with the pressing portion 65 attached, the filling liquid is solidified. In other words, the filling liquid solidifies and forms the filler material 53 while the gap between the intermediate member 5 and the first heat dissipation member 6 is reduced.

As described above, the intermediate member 5 can be reliably joined by the filler 53 while reducing the gap between the intermediate member 5 and the first heat dissipation member 6. This reduces the thermal resistance between the intermediate member 5 and the first heat dissipation member 6.

If the light emitting device 1 includes the second resin member 52, the pressing portion 65 may be attached at the timing described below. First, a filling liquid, which is the filler material 53 before solidification, is applied to the space inside the solidified first resin member 51, and a resin liquid, which is the second resin member 52 before solidification, is applied between the solidified first resin member 51 and the first heat dissipation member 6. Next, the indirect member 5 with the wavelength conversion member 4 attached is placed on top of the first resin member 51 and the first heat dissipation member 6. Next, the pressing portion 65 is attached to the indirect member 5 and the first heat dissipation member 6. This presses the indirect member 5 toward the first heat dissipation member 6. At this time, the filling liquid may be pressed by the indirect member 5 or may spill out between the indirect member 5 and the first resin member 51. Similarly, the resin liquid may be pressed by the indirect member 5 or may spill out between the indirect member 5 and the first heat dissipation member 6. Because the intermediate member 5 is pressed toward the first heat dissipation member 6, the gap between the intermediate member 5 and the first heat dissipation member 6 is reduced. As a result, the resin liquid spreads thinly between the intermediate member 5 and the first heat dissipation member 6. Next, with the pressing portion 65 attached, the filling liquid and resin liquid are solidified.

As described above, the intermediate member 5 can be reliably bonded by the filler 53 and the second resin member 52, while the gap between the intermediate member 5 and the first heat dissipation member 6 can be reduced. In other words, the thickness of the second resin member 52 can be reduced. Furthermore, because the resin liquid spreads thinly between the intermediate member 5 and the first heat dissipation member 6, the gap between the intermediate member 5 and the first heat dissipation member 6 can be more reliably reduced. Therefore, the thermal resistance between the intermediate member 5 and the first heat dissipation member 6 can be more reliably reduced.

Furthermore, in the above example, the pressing portion 65 includes a pressing member 66 and a fastening member 67. This allows the pressing member 66 to be attached to the first heat dissipation member 6 with a simpler structure, while pressing the indirect member 5 toward the first heat dissipation member 6.

Next, the thermal conductivity of the pressing portion 65 will be described. The thermal conductivity of the pressing member 66 of the pressing portion 65 may be higher than that of the wavelength conversion member 4, and may also be higher than that of the intermediate member 5. For example, the pressing member 66 is formed from at least one of a metal and a ceramic. Examples of metals that can be used include silver, copper, gold, aluminum, zinc, chromium, nickel, or tin, or an alloy containing at least one of these. Examples of ceramics that can be used include silicon carbide or aluminum nitride.

The thermal conductivity of the fastening member 67 may be higher than that of the wavelength conversion member 4, and may also be higher than that of the intermediate member 5. For example, the fastening member 67 is made of at least one of a metal and a ceramic. Examples of metals that can be used include iron, silver, copper, gold, aluminum, zinc, chromium, nickel, and tin, as well as alloys containing at least one of these (e.g., stainless steel). Examples of ceramics that can be used include silicon carbide and aluminum nitride.

As described above, when the thermal conductivity of the pressing member 66 is high, the pressing member 66 can more effectively dissipate the heat received from the intermediate member 5 to the outside. It is also possible to transfer heat from the pressing member 66 to the first heat dissipation member 6. For example, it is also possible to transfer heat from the pressing member 66 to the first heat dissipation member 6 via the fastening member 67. This further improves the heat dissipation performance of the light emitting device 1.

Next, the shape of the fourth portion 662 will be described. As shown in FIG. 25, a portion of the fourth portion 662 of the pressing member 66 may be located closer to the first heat dissipation member 6 than the third portion 661. In other words, the fourth portion 662 is located in a state where it protrudes closer to the first heat dissipation member 6 than the third portion 661. The amount by which the fourth portion 662 protrudes from the third portion 661 is equal to or less than the thickness of the intermediate member 5. As a result, the portion of the fourth portion 662 faces at least a portion of the side surface 5c of the intermediate member 5 in a direction parallel to the first surface of the substrate 21. The fourth portion 662 may cover at least a portion of the side surface 5c of the intermediate member 5. In other words, the fourth portion 662 may partially cover the side surface 5c of the intermediate member 5 from the outside. The side surface 5c of the intermediate member 5 may be partially covered by the fourth portion 662, or may be partially exposed. For example, when the intermediate member 5 is a rectangular plate-shaped member, the fourth portion 662 may cover the side surface of the corner of the intermediate member 5, or the fourth portion 662 may cover the entire intermediate member 5 other than the corners.

This structure allows the distance between the fourth portion 662 of the pressing member 66 and the first heat dissipation member 6 to be reduced. This reduces the thermal resistance between the pressing member 66 and the first heat dissipation member 6. This allows heat from the intermediate member 5 to be more effectively transferred to the first heat dissipation member 6 through the pressing member 66. Note that when the fastening member 67 is attached, the fourth portion 662 may be in contact with the first surface 6a of the first heat dissipation member 6.

Hereinafter, the surface of the fourth portion 662 that faces the side surface 5c of the indirect member 5 will also be referred to as the "facing surface."

The fluorescence and excitation light emitted from the side surface 5c of the intermediate member 5 are incident on the opposing surface of the fourth portion 662. The transmittance of the fourth portion 662 for at least one of the fluorescence and excitation light may be lower than the transmittance of the intermediate member 5. For example, the transmittance of the fourth portion 662 for at least one of the fluorescence and excitation light may be 10% or less, 5% or less, 2% or less, or 1% or less. This prevents at least one of the fluorescence and excitation light from passing through the fourth portion 662 of the pressing member 66 to a large extent. This reduces the amount of fluorescence or excitation light emitted from the side surface 5c of the intermediate member 5 into the illumination space. This allows the light-emitting device 1 to emit illumination light with higher definition.

At least one of the fluorescence and the excitation light may be absorbed by the fourth portion 662. For example, the fourth portion 662 may be formed of black silicon carbide. Alternatively, at least one of the fluorescence and the excitation light may be reflected by the fourth portion 662. For example, the reflectance of the fourth portion 662 for at least one of the fluorescence and the excitation light may be 50% or more, 60% or more, 70% or more, 80% or more, or 90% or more. The above-mentioned materials exemplified as materials for the pressing member 66 have high reflectance for the fluorescence and the excitation light. When aluminum is used for the pressing member 66, the fourth portion 662 may be anodized. At least one of the fluorescence and the excitation light reflected by the opposing surface of the fourth portion 662 may be incident on the wavelength conversion member 4 again through the indirect member 5. This allows the light emitting device 1 to emit illumination light with higher brightness.

Figure 30 is a plan view schematically showing a second example of the configuration of the light emitting device 1 according to the tenth embodiment. The light emitting device 1 according to the second example of the tenth embodiment differs from the light emitting device 1 according to the first example of the tenth embodiment in the configuration of the pressing member 66 of the pressing portion 65. As shown in Figure 30, the pressing member 66 may have an annular shape in plan view. The pressing member 66 may surround the wavelength conversion member 4 in plan view. In other words, the inner surface of the pressing member 66 may surround the side surface of the wavelength conversion member 4. The pressing member 66 may have an annular shape, and the wavelength conversion member 4 may have a disk shape. The inner diameter (diameter) of the pressing member 66 may be equal to or greater than the diameter of the wavelength conversion member 4.

The pressing member 66 includes a third portion 661 and a fourth portion 662. The third portion 661 faces the intermediate member 5, and the fourth portion 662 faces the first heat dissipation member 6 outside the intermediate member 5. As shown in FIG. 30, the third portion 661 may have an annular shape. That is, the third portion 661 may face the intermediate member 5 over the entire circumference of the wavelength conversion member 4. For example, the inner diameter (diameter) of the pressing member 66 may be shorter than one side of the intermediate member 5, and the outer diameter (diameter) of the pressing member 66 may be longer than one side of the intermediate member 5. In this case, the third portion 661 has an annular shape. On the other hand, the fourth portion 662 is separated into multiple portions. In the example of FIG. 30, four fourth portions 662 are located outside the intermediate member 5. Each fourth portion 662 may have an arch-shaped shape in a plan view.

On the other hand, although different from Figure 30, the inner diameter of the pressing member 66 may be longer than one side of the indirect member 5 and shorter than the diagonal of the indirect member 5. In this case, the multiple third portions 661 face the multiple corners of the indirect member 5, respectively. As a result, the inner diameter of the pressing member 66 is relatively large, and the diameter of the wavelength conversion member 4 can be made large. The outer diameter of the pressing member 66 may be longer than the diagonal of the indirect member 5. In this case, the fourth portion 662 has an annular shape. In other words, the fourth portion 662 is located outside the indirect member 5 all around the circumference.

As shown in FIG. 30, the fastening members 67 may be attached one-to-one to the sides of the indirect member 5. The fastening members 67 may be attached to positions adjacent to the center of each side of the indirect member 5 in a plan view. In this way, by fastening the fastening members 67, the pressing member 66 can press the indirect member 5 more evenly toward the first heat dissipation member 6.

According to the second example of the tenth embodiment, the third portion 661 of the pressing member 66 is in contact with the intermediate member 5 over a larger area. For example, the pressing member 66 can press all corners of the intermediate member 5. This allows heat from the intermediate member 5 to be effectively transferred to the outside or to the first heat dissipation member 6 through the pressing member 66. This further improves the heat dissipation performance of the light-emitting device 1.

The thickness of the third portion 661 of the pressing member 66 may be smaller than the thickness of the wavelength conversion member 4, but may also be larger. If the third portion 661 is thicker than the wavelength conversion member 4, the pressing member 66 can more effectively release heat to the outside. The third portion 661 may be thicker than the first heat dissipation member 6 and may also be thicker than the substrate 21.

Eleventh Embodiment
31 is a perspective view schematically illustrating a first example of the configuration of the lighting device 10 according to the eleventh embodiment. The lighting device 10 according to the first example of the eleventh embodiment differs from the lighting device 10 according to the third embodiment in the presence or absence of a pressing portion 65. In the eleventh embodiment, the light-emitting device 1 includes an indirect member 5.

In the eleventh embodiment, the second heat dissipation member 91 also functions as a pressing portion 65. Specifically, the second heat dissipation member 91 has a pressing member 66. As shown in FIG. 31 , a portion of the second heat dissipation member 91 faces a portion of the intermediate member 5 in the thickness direction of the substrate 21, and functions as a third portion 661 of the pressing member 66. As in the first example of the tenth embodiment, the second heat dissipation member 91 may include multiple third portions 661. As a specific example, the first heat dissipation member 6 may include two third portions 661. One third portion 661 may face the first corner portion 551 of the intermediate member 5, and the other third portion 661 may face the second corner portion 552 of the intermediate member 5.

As shown in FIG. 31 , the third portion 661 may form part of the outline of the opening 91a of the second heat dissipation member 91. The opening 91a of the second heat dissipation member 91 may have a shape that extends along a diagonal line connecting the third corner 553 and the fourth corner 554 of the intermediate member 5. The opening 91a may be an elongated hole that is long in the direction along the diagonal line. The second heat dissipation member 91 does not have to face the third corner 553 and the fourth corner 554 of the intermediate member 5 in the thickness direction of the board 21. In other words, in a plan view, the third corner 553 and the fourth corner 554 of the intermediate member 5 may be located inside the opening 91a.

As can be seen from FIG. 31, a portion of the second heat dissipation member 91 faces the first heat dissipation member 6 outside the intermediate member 5 in the thickness direction of the substrate 21, and functions as the fourth portion 662 of the pressing member 66. As with the first example of the tenth embodiment, the second heat dissipation member 91 may include multiple fourth portions 662. As a specific example, the second heat dissipation member 91 may include two fourth portions 662. One fourth portion 662 may face the heat dissipation member 61, and the other fourth portion 662 may face the heat dissipation member 62.

A through hole 65a is formed in the fourth portion 662 of the second heat dissipation member 91, and is penetrated by a fastening member 67. As in the first example of the tenth embodiment, multiple through holes 65a may be formed in each fourth portion 662. As a specific example, two through holes 65a may be formed in each fourth portion 662. As in the first example of the tenth embodiment, each corner of the intermediate member 5 may be located between two through holes 65a in each fourth portion 662.

By fastening the fastening member 67, the second heat dissipation member 91 is pressed toward the first heat dissipation member 6, and the third portion 661 of the second heat dissipation member 91 presses the intermediate member 5 toward the first heat dissipation member 6. This reduces the thermal resistance between the intermediate member 5 and the first heat dissipation member 6. This also reduces the thermal resistance between the fourth portion 662 of the second heat dissipation member 91 and the first heat dissipation member 6. This pressure also reduces the thermal resistance between the third portion 661 of the second heat dissipation member 91 and the intermediate member 5. This allows heat to be more effectively transferred from the intermediate member 5 to each of the first heat dissipation member 6 and the second heat dissipation member 91.

As in the third embodiment, portion 91c of the second heat dissipation member 91 may also face the heat sink 92. Portion 91c may be in contact with the first surface 92a of the heat sink 92, and a highly thermally conductive resin such as thermal grease may be positioned between portion 91c and the heat sink 92. With this structure, heat transferred from the intermediate member 5 to the second heat dissipation member 91, either directly or via the first heat dissipation member 6, can be transferred to the heat sink 92.

By fastening the fastening member 67, the portion 91c of the second heat dissipation member 91 may be pressed toward the heat sink 92. In this case, the thermal resistance between the portion 91c of the second heat dissipation member 91 and the heat sink 92 can be reduced. This allows heat to be transferred more effectively from the second heat dissipation member 91 to the heat sink 92.

As in the third embodiment, the second heat dissipation member 91 may be in contact with the inner circumferential surface of the cylindrical body 93. For example, portion 91c of the second heat dissipation member 91 may be in contact with the inner circumferential surface of the cylindrical body 93. This allows heat from the intermediate member 5 to be transferred to the cylindrical body 93 via the second heat dissipation member 91. This further improves the heat dissipation performance of the lighting device 10.

As in the tenth embodiment, a portion of the fourth portion 662 of the second heat dissipation member 91 may face at least a portion of the side surface 5c of the intermediate member 5 in a direction parallel to the first surface of the substrate 21. This reduces the possibility that fluorescence and excitation light will be emitted into the illumination space, even if fluorescence and excitation light are emitted from at least a portion of the side surface 5c of the intermediate member 5.

Figure 32 is a perspective view that schematically illustrates a second example of the configuration of the lighting device 10 according to the 11th embodiment. The lighting device 10 according to the second example of the 11th embodiment differs from the lighting device 10 according to the first example of the 11th embodiment in the configuration of the second heat dissipation member 91.

In the example of Figure 32, the second heat dissipation member 91 also functions as the pressing member 66. As shown in Figure 32, the opening 91a may have a circular shape in a plan view, and the second heat dissipation member 91 (specifically, the third portion 661) may face each of the first corner 551 to the fourth corner 554 of the intermediate member 5. In other words, the second heat dissipation member 91 may face all of the corners of the intermediate member 5. As shown in Figure 32, the third portion 661 of the second heat dissipation member 91 may form the entire outline of the opening 91a.

According to the second example of the eleventh embodiment, the third portion 661 of the second heat dissipation member 91 contacts the intermediate member 5 over a larger area. Therefore, by fastening the fastening member 67, the second heat dissipation member 91 can press the intermediate member 5 more evenly toward the first heat dissipation member 6. This allows heat from the intermediate member 5 to be more effectively transferred to the heat sink 92 or the cylindrical body 93 via the second heat dissipation member 91. This further improves the heat dissipation performance of the lighting device 10.

The second heat dissipation member 91 may be integrally formed from the same material, or may be composed of a combination of multiple members. These multiple members may be in contact with each other, or a highly thermally conductive resin may be positioned between the members. At least two of the multiple members may be formed from different materials. Here, the same material means that the main components are the same, and may contain different components.

<Twelfth and Thirteenth Embodiments>
As a twelfth embodiment, as shown in Fig. 33 , the light emitting device 1 may not include the first resin member 51, and the wavelength conversion member 4 may be placed on top of the first heat dissipation member 6. Furthermore, as a thirteenth embodiment, as shown in Fig. 34 , the light emitting device 1 may not include the first resin member 51, and the wavelength conversion member 4 may be placed on top of the first heat dissipation member 6 via an intermediate member 5. In any of the embodiments, the light emitting element 3 and the wavelength conversion member 4, which can be heat sources, are located apart in the thickness direction of the substrate 21, and therefore can be less susceptible to the thermal influence of each other.

In both the twelfth and thirteenth embodiments, a portion of the peripheral edge of the wavelength conversion member 4 may face the first heat dissipation member 6 in the thickness direction of the substrate 21. That is, in a plan view, a portion of the wavelength conversion member 4 may overlap the first heat dissipation member 6. A portion of the wavelength conversion member 4 may overlap the heat dissipation member 61, and another portion of the wavelength conversion member 4 may overlap the heat dissipation member 62. In the thirteenth embodiment, a portion of the peripheral edge of the intermediate member 5 may face the first heat dissipation member 6 in the thickness direction of the substrate 21. That is, in a plan view, a portion of the intermediate member 5 may overlap the first heat dissipation member 6. A portion of the intermediate member 5 may overlap the heat dissipation member 61, and another portion of the intermediate member 5 may overlap the heat dissipation member 62.

Furthermore, a filler 53 may be located in the area surrounded by the first heat dissipation member 6. The filler 53 may have the same characteristics as in the first embodiment, except that it is surrounded by the first resin member 51. The filler 53 may be located in at least the portion of the area surrounded by the first heat dissipation member 6 that covers the light-emitting element 3.

As mentioned above, the light-emitting device 1 and the lighting device 10 have been described in detail, but the above description is illustrative in all respects and this disclosure is not limited thereto. Furthermore, the various examples described above can be applied in combination as long as they are not mutually contradictory. It is understood that countless examples not illustrated can be envisioned without departing from the scope of this disclosure.

This disclosure includes the following:

In one embodiment, (1) the light-emitting device may include a substrate, a wavelength conversion member that emits illumination light based on excitation light, a first light-emitting element that is located between the substrate and the wavelength conversion member and emits the excitation light, and a first heat dissipation member that is located between the substrate and the wavelength conversion member and away from the first light-emitting element, and that has a thermal conductivity higher than that of the wavelength conversion member.

(2) The light-emitting device of (1) above may further include a first resin member located between the substrate portion and the wavelength conversion member and surrounding the first light-emitting element in a planar view, and the first heat dissipation member may be adjacent to the first resin member on the outside of the first resin member with a gap therebetween.

(3) In the light-emitting device of (1) or (2) above, the peripheral edge of the wavelength conversion member can be positioned outside the inner peripheral edge of the first resin member in a plan view.

(4) Any one of the light-emitting devices (1) to (3) above may further include an intermediate member having a first surface and a second surface, being translucent to the excitation light, and having a thermal conductivity higher than that of the wavelength conversion member, wherein the peripheral edge of the second surface of the intermediate member may face a portion of the first heat dissipation member, and the wavelength conversion member may be positioned on the first surface of the intermediate member.

(5) In the light-emitting device of (4) above, the wavelength conversion member can include a plurality of phosphor particles and a binder layer bonding the plurality of phosphor particles together, and the wavelength conversion member can be bonded to the intermediate member.

(6) In the light-emitting device of (4) or (5) above, the fracture strength of the intermediate member may be higher than the fracture strength of the wavelength conversion member.

(7) Any one of the light-emitting devices described in (4) to (6) above may further include a first heat transfer member that is in contact with the second surface of the intermediate member and has a thermal conductivity higher than that of the intermediate member, and the first heat transfer member may include a first portion that faces the first heat dissipation member and a second portion that is connected to the first portion and is located closer to the first resin member than the first heat dissipation member in a planar view, and may have a first opening that passes the excitation light from the first light-emitting element in a region that faces at least a portion of the wavelength conversion member.

(8) In the light-emitting device of (7) above, the outline of the first opening can be positioned outside the inner peripheral edge of the first resin member.

(9) In the light-emitting device of (7) or (8) above, the first heat transfer member can be joined to the intermediate member.

(10) The light-emitting device according to any one of (7) to (9) above may further include a second heat transfer member, the second heat transfer member having a thermal conductivity higher than that of the intermediate member, and being in contact with the first surface of the intermediate member.

(11) In the light-emitting device of (10) above, the second heat transfer member may have a second opening, and the outline of the second opening may surround the wavelength conversion member.

(12) The light-emitting device of (10) or (11) above may further include a third heat transfer member, the third heat transfer member having a thermal conductivity higher than that of the intermediate member, and the first heat transfer member and the second heat transfer member may be connected in contact with the side surface of the intermediate member.

(13) In the light-emitting device of (12) above, the transmittance of the third heat transfer member for the illumination light may be lower than the transmittance of the indirect member for the illumination light.

(14) In the light-emitting device of (13) above, the first heat transfer member, the second heat transfer member, and the third heat transfer member can be formed from the same material.

(15) Any one of the light-emitting devices (7) to (14) above may further include a pressing portion that presses the intermediate member toward the first heat dissipation member.

(16) In the light-emitting device of (15) above, the thermal conductivity of the pressing portion may be higher than the thermal conductivity of the wavelength conversion member.

(17) In the light-emitting device of (15) or (16) above, the pressing portion may include a pressing member and a fastening member, the pressing member may include a third portion located on the first surface side of the intermediate member and a fourth portion connected to the third portion and located outside the intermediate member, and the fastening member may fasten the pressing member to the first heat dissipation member through a through hole formed in the fourth portion.

(18) In the light-emitting device of (17) above, the fourth portion includes a portion that partially covers the side surface of the connecting member from the outside.

(19) Any one of the light-emitting devices (1) to (18) above may further include a second resin member positioned between the first resin member and the first heat dissipation member and having a thermal conductivity higher than that of air.

(20) The light-emitting device according to any one of (1) to (19) above may further include an electronic component located between the first resin member and the first heat dissipation member.

(21) In the light-emitting device of (20) above, the electronic component may include a protective element that protects the first light-emitting element.

(22) Any one of the light-emitting devices (1) to (21) above may further include a second light-emitting element that emits light having a wavelength different from the wavelength of the excitation light of the first light-emitting element.

(23) The light-emitting device of (22) above may include a first electrode connected to the first light-emitting element, and a second electrode connected to the second light-emitting element and to which a voltage different from the voltage applied to the first electrode is applied.

(24) In the light-emitting device of (23) above, the wavelength conversion member may include a first phosphor that emits a first fluorescence based on the excitation light and a second phosphor that emits a second fluorescence based on the excitation light, and the wavelength dependence of the absorption rate of the second phosphor for the excitation light may be greater than the wavelength dependence of the absorption rate of the first phosphor for the excitation light, and the second light-emitting element may emit light having a wavelength closer to the wavelength of the second fluorescence than to the wavelength of the first fluorescence.

(25) Any one of the light-emitting devices (1) to (24) above may include a first electrode connected to the first light-emitting element, and in a planar view, at least a portion of the first resin member may be positioned to overlap at least a portion of the first electrode, and the first heat dissipation member may be conductive and may be positioned in a region that avoids the first electrode in a planar view.

(26) Any one of the light-emitting devices (1) to (25) above may further include a reflector that is reflective to the excitation light, and the substrate portion may include a substrate, an insulating film on the substrate, and a first electrode located on the insulating film, the first light-emitting element may be located on the first electrode and connected to the first electrode, and the reflector may be located on the insulating film at a position adjacent to the first light-emitting element.

(27) In any one of the light-emitting devices (1) to (26) above, the substrate portion may include a substrate that is reflective to the excitation light, and the light-emitting device may include an insulating film located on the substrate at a position adjacent to the first light-emitting element, and a first electrode located on the insulating film and electrically connected to the first light-emitting element by a wire.

(28) The lighting device may include any one of the light-emitting devices (1) to (27) above, a cylindrical body that houses the light-emitting device, and a second heat-dissipating member that contacts the first heat-dissipating member and the inner surface of the cylindrical body.

(29) The lighting device may include the light-emitting device of (17) or (18) above, a cylindrical body that houses the light-emitting device, and a second heat-dissipating member that contacts the first heat-dissipating member and the inner surface of the cylindrical body, and the second heat-dissipating member may have the pressing member.

REFERENCE SIGNS LIST 1 Light emitting device 10 Lighting device 2 Substrate portion 21 Substrate 22 Insulating film 3 First light emitting element (light emitting element)
35 Electronic component 3A, 3D Second light-emitting element (light-emitting element)
3B, 3C First light-emitting element (light-emitting element)
4 Wavelength conversion member 41 Phosphor particles 41a First phosphor 41b Second phosphor 42 Binder layer 5 Intermediate member 5a First surface 5b Second surface 5c Side surface 51 First resin member 52 Second resin member 561 First heat transfer member 562 Second heat transfer member 563 Third heat transfer member 56a First opening 56b Second opening 571 First portion 572 Second portion 6 First heat dissipation member 65 Pressing portion 65a Through hole 66 Pressing member 661 Third portion 662 Fourth portion 67 Fastening member 71a First electrode (element electrode)
77a Second electrode (element electrode)
8 Reflector 91 Second heat dissipation member 93 Cylindrical body

Claims (29)

A substrate portion;
a wavelength conversion member that emits illumination light based on the excitation light;
a first light-emitting element located between the substrate portion and the wavelength converting member and emitting the excitation light;
a first heat dissipation member positioned between the substrate portion and the wavelength conversion member and spaced apart from the first light emitting element, the first heat dissipation member having a thermal conductivity higher than that of the wavelength conversion member. 2. The light emitting device according to claim 1,
a first resin member positioned between the substrate portion and the wavelength conversion member and surrounding the first light emitting element in a plan view;
the first heat dissipation member is adjacent to the first resin member at an interval outside the first resin member. 3. The light emitting device according to claim 2,
In a plan view, a peripheral edge of the wavelength conversion member is located outside an inner peripheral edge of the first resin member. 4. The light emitting device according to claim 1,
an intermediate member having a first surface and a second surface, being translucent to the excitation light, and having a thermal conductivity higher than that of the wavelength conversion member;
a peripheral portion of the second surface of the intermediate member faces a part of the first heat dissipation member,
The wavelength conversion member is located on the first surface of the supporting member. 5. The light emitting device according to claim 4,
the wavelength conversion member includes a plurality of phosphor particles and a binder layer that bonds the plurality of phosphor particles together,
The wavelength conversion member is joined to the intermediate member. 6. The light emitting device according to claim 4 or claim 5,
The light emitting device, wherein the fracture strength of the intermediate member is higher than the fracture strength of the wavelength conversion member. 7. The light emitting device according to claim 4,
a first heat transfer member in contact with the second surface of the intermediate member and having a thermal conductivity higher than that of the intermediate member;
The first heat transfer member is
a first portion facing the first heat dissipation member;
a second portion connected to the first portion and positioned closer to the first resin member than the first heat dissipation member in a planar view, and having a first opening in an area facing at least a portion of the wavelength conversion member that allows the excitation light from the first light-emitting element to pass through. 8. The light emitting device according to claim 7,
a contour of the first opening positioned outside an inner periphery of the first resin member; 9. The light emitting device according to claim 7 or claim 8,
The light emitting device, wherein the first heat transfer member is joined to the intermediate member. 10. The light emitting device according to claim 7,
Further comprising a second heat transfer member;
The second heat transfer member has a thermal conductivity higher than that of the intermediate member and is in contact with the first surface of the intermediate member. 11. The light emitting device according to claim 10,
the second heat transfer member has a second opening;
The outline of the second opening surrounds the wavelength converting member. 12. The light emitting device according to claim 10 or 11,
further comprising a third heat transfer member;
A light emitting device, wherein the third heat transfer member has a thermal conductivity higher than that of the intermediate member, and connects the first heat transfer member and the second heat transfer member while being in contact with a side surface of the intermediate member. 13. The light emitting device according to claim 12,
a transmittance of the third heat transfer member for the illumination light being lower than a transmittance of the intermediate member for the illumination light; 14. The light emitting device according to claim 13,
The light emitting device, wherein the first heat transfer member, the second heat transfer member, and the third heat transfer member are formed of the same material. 15. The light emitting device according to claim 7,
The light emitting device further includes a pressing portion that presses the intermediate member toward the first heat dissipation member. 16. The light emitting device according to claim 15,
The light emitting device, wherein the pressing portion has a thermal conductivity higher than that of the wavelength conversion member. 17. The light emitting device according to claim 15 or claim 16,
the pressing portion includes a pressing member and a fastening member,
The pressing member is
a third portion located on the first surface side of the intermediate member;
a fourth portion connected to the third portion and positioned outside the intermediate member,
The fastening member fastens the pressing member to the first heat dissipation member through a through hole formed in the fourth portion. 18. The light emitting device according to claim 17,
The fourth portion includes a portion that partially covers a side surface of the connecting member from the outside. 19. The light emitting device according to claim 1,
The light emitting device further comprises a second resin member positioned between the first resin member and the first heat dissipation member, the second resin member having a thermal conductivity higher than that of air. 20. The light emitting device according to claim 1,
The light emitting device further comprises an electronic component located between the first resin member and the first heat dissipation member. 21. The light emitting device according to claim 20,
The electronic component includes a protection element that protects the first light-emitting element. 22. The light emitting device according to claim 1,
The light emitting device further comprises a second light emitting element that emits light having a wavelength different from the wavelength of the excitation light of the first light emitting element. 23. The light emitting device according to claim 22,
a first electrode connected to the first light emitting element;
a second electrode connected to the second light-emitting element and applied with a voltage different from the voltage applied to the first electrode; 24. The light emitting device according to claim 23,
The wavelength conversion member is
a first fluorescent material that emits a first fluorescent light in response to the excitation light;
a second fluorescent material that emits a second fluorescent light based on the excitation light,
the wavelength dependence of the absorptance of the second phosphor with respect to the excitation light is greater than the wavelength dependence of the absorptance of the first phosphor with respect to the excitation light;
The second light-emitting element emits light having a wavelength closer to the wavelength of the second fluorescent light than to the wavelength of the first fluorescent light. 25. The light emitting device according to claim 1,
a first electrode connected to the first light-emitting element;
In a plan view, at least a portion of the first resin member is located at a position overlapping at least a portion of the first electrode,
The light emitting device, wherein the first heat dissipation member is electrically conductive and is located in a region that avoids the first electrode in a plan view. 26. The light emitting device according to claim 1,
further comprising a reflector having reflectivity for the excitation light,
The substrate portion is
A substrate;
an insulating film on the substrate;
a first electrode located on the insulating film;
the first light emitting element is located on the first electrode and connected to the first electrode;
The light-emitting device, wherein the reflector is located on the insulating film at a position adjacent to the first light-emitting element. 27. The light emitting device according to claim 1,
the substrate unit includes a substrate that is reflective to the excitation light,
The light emitting device comprises:
an insulating film located on the substrate at a position adjacent to the first light emitting element;
a first electrode located on the insulating film and electrically connected to the first light-emitting element by a wire; a light emitting device according to any one of claims 1 to 27;
a cylindrical body that houses the light emitting device;
a second heat dissipation member in contact with the inner circumferential surface of the cylindrical body; a light-emitting device according to claim 17 or 18;
a cylindrical body that houses the light emitting device;
a second heat dissipation member in contact with the first heat dissipation member and an inner circumferential surface of the cylindrical body,
The second heat dissipation member includes the pressing member.