WO2012011528A1 - Light-emitting device and lighting device - Google Patents

Abstract

The disclosed light-emitting device is provided with: a substrate; a light-emitting element arranged on the main surface of the substrate; and a wavelength conversion member which is arranged on the light-emitting element, and which has an inner surface that faces the light-emitting element and an outer surface on the reverse side of the inner surface. The inner surface is a concave shaped curved surface. The outer surface has a flat surface and convex shaped curved surfaces positioned so as to enclose the flat surface. The flat surface is positioned so as to overlap with the light-emitting element, when viewed in the planar perspective.

Description

Light emitting device and lighting device

The present invention relates to a light emitting device and a lighting device provided with a light emitting element. The light emitting device and the lighting device can be suitably used for, for example, a backlight power source for an electronic display and a fluorescent lamp.

In recent years, development of light-emitting devices having light-emitting elements typified by LEDs has been underway. As a light emitting device, a configuration disclosed in Patent Document 1 is known. At least a part of the primary light emitted from the light emitting element is wavelength-converted into secondary light having a wavelength different from that of the primary light in the wavelength conversion member containing the phosphor. The wavelength-converted secondary light is emitted outside the light emitting device. In particular, when a light emitting device is used as a light source device of a lighting fixture that performs illumination with white light, a wavelength conversion member is preferably used in order to emit white light.

Patent Document 1 discloses a resin (wavelength conversion member) containing a fluorescent material whose inner surface has a concave dome shape. Compared with the case where the inner surface of the wavelength conversion member has a flat plate shape, when the inner surface has a concave shape, the incident angle of the light emitted from the light emitting element and entering the wavelength conversion member tends to be small. Therefore, it becomes difficult to reflect on the inner surface of the wavelength conversion member, and more light can enter the wavelength conversion member.

Further, when the outer surface has a convex shape corresponding to the concave shape of the inner surface of the wavelength conversion member, such as when the thickness of the wavelength conversion member is constant, the wavelength conversion of the light traveling in the wavelength conversion member The incident angle on the outer surface of the member tends to be small. Therefore, the amount of light extracted to the outside as the entire light emitting device can be increased.

However, when a light-emitting device is used as a light source device of a lighting fixture, emitted light from the light-emitting device is often emitted toward a generally flat irradiation surface. For this reason, the amount of light irradiated per unit area is relatively small in a portion located obliquely above the light emitting device on the irradiation surface compared to a portion located directly above the light emitting device on the irradiation surface. As a result, the variation in the amount of light irradiated between the portion located directly above the light emitting device on the irradiation surface and the portion located obliquely above the light emitting device becomes large, which may cause large light emission unevenness. .
JP 2004-343149 A

A light emitting device according to an aspect of the present invention includes a base, a light emitting element disposed on a main surface of the base, an inner surface disposed on the light emitting element and facing the light emitting element, and the light emitting element. A wavelength conversion member having an outer surface opposite to the inner surface. The inner surface of the wavelength conversion member is a concave curved surface. The outer surface of the wavelength conversion member has a flat surface and a convex curved surface positioned so as to surround the flat surface. The flat surface is positioned so as to overlap the light emitting element when viewed through.

It is a top view which shows the light-emitting device of 1st Embodiment. FIG. 2 is a cross-sectional view taken along the line AA of the light emitting device shown in FIG. It is sectional drawing which shows the light-emitting device of 2nd Embodiment. It is sectional drawing which shows the light-emitting device of 3rd Embodiment. It is sectional drawing which shows the light-emitting device of 4th Embodiment. It is sectional drawing which shows the light-emitting device of 5th Embodiment. It is sectional drawing which shows the light-emitting device of 6th Embodiment. It is a perspective sectional view showing an illuminating device concerning one embodiment of the present invention.

Hereinafter, a light-emitting device and a lighting device according to each embodiment of the present invention will be described in detail with reference to the drawings. However, in the drawings referred to below, for convenience of explanation, among the constituent members of each embodiment, only the main members necessary for explaining the present invention are shown in a simplified manner. Therefore, the light-emitting device according to the present invention can include arbitrary constituent members that are not shown in the drawings referred to in this specification. Moreover, the dimension of the member in each figure does not represent the dimension of an actual structural member, the dimension ratio of each member, etc. faithfully.

As shown in FIGS. 1 and 2, the light emitting device 1 of the first embodiment is provided with a base 3, a light emitting element 5 provided on the main surface of the base 3, and a light emitting element 5. And a wavelength conversion member 7. The wavelength conversion member 7 has an inner surface (lower surface in FIG. 2) facing the light emitting element 5 and an outer surface (upper surface in FIG. 2) opposite to the inner surface.

The inner surface of the wavelength conversion member 7 is a concave curved surface. The outer surface of the wavelength conversion member 7 has a flat surface and a convex curved surface positioned so as to surround the flat surface. The flat surface is positioned so as to overlap the light emitting element 5 when seen through the plane.

In the light emitting device 1 of the present embodiment, the wavelength conversion member 7 has a central portion 7d including a region overlapping the light emitting element 5 and a peripheral portion 7e positioned so as to surround the central portion 7d when seen in a plan view. Yes. For convenience, the outer surface of the central portion 7d is referred to as a central region 7a. For convenience, the outer surface of the peripheral portion 7e is referred to as a peripheral region 7b. In the light emitting device 1 of the present embodiment, the central region 7a corresponds to the flat surface described above. The peripheral area 7b corresponds to the convex curved surface described above.

When the entire outer surface of the wavelength conversion member 7 is flat, light traveling from the inside of the wavelength conversion member 7 to the outer surface is easily reflected on the outer surface. At this time, the incident angle of the light traveling obliquely upward from the light emitting element 5 to the outer surface of the wavelength converting member 7 is incident on the outer surface of the wavelength converting member 7 while the light traveling from the light emitting element 5 in the directly upward direction. It tends to be larger than the corner. For this reason, light traveling obliquely upward from the light emitting element 5 is relatively easily reflected on the outer surface as compared with light traveling in the upward direction from the light emitting element 5. As a result, it becomes difficult to reduce the variation between the amount of light emitted in the direction directly above the light emitting element 5 and the amount of light emitted obliquely above the light emitting element 5.

Further, when the wavelength conversion member 7 has a constant thickness and the entire outer surface is a convex curved surface, as already shown, the amount of light extracted to the outside as the entire light emitting device 1 is increased, thereby improving the luminous efficiency. Can be bigger. However, the amount of light irradiated per unit area of the portion located obliquely above the light emitting device 1 on the irradiation surface is relatively small as compared to the portion located directly above the light emitting device 1 on the irradiation surface. Therefore, there is a possibility that large light emission unevenness occurs.

On the other hand, in the light emitting device 1 of the present embodiment, the inner surface of the wavelength conversion member 7 is a concave curved surface. The outer surface of the wavelength conversion member 7 has a flat surface and a convex curved surface positioned so as to surround the flat surface. The flat surface is positioned so as to overlap the light emitting element 5 when seen through the plane.

Thereby, a portion whose outer surface is a flat surface (in the light emitting device 1 of the present embodiment, the central portion 7d whose outer surface is the central region 7a) can function as a concave lens. In addition, a portion whose outer surface is a convex curved surface (in the light emitting device 1 of the present embodiment, the peripheral portion 7e whose outer surface is the peripheral region 7b) can function as a convex lens. Since the central portion 7d including the portion that overlaps the light emitting element 5 when seen in a plan view functions as a concave lens, the light emitted from the central region 7a can be efficiently dispersed obliquely above the light emitting device 1. Therefore, it is possible to reduce variation in the amount of light irradiated in the direction directly above the light emitting device 1 on the irradiation surface and the amount of light irradiated in the obliquely upward direction of the light emitting device 1 on the irradiation surface.

Specifically, since the central region 7a is a flat surface, the light that travels through the wavelength conversion member 7 and enters the central region 7a is partially refracted by the central region 7a, thereby irradiating the surface. It becomes easy to advance to the part located diagonally above the light emitting device 1 in FIG. In addition, since light emitted in a direction directly above the light emitting element 5 having a relatively large amount of light is easily reflected in the central region 7a which is a flat surface, the amount of light emitted in the direction directly above the light emitting element 5 is reduced. Can be suppressed. Further, a part of the light incident on the central region 7a is reflected in the central region 7a as described above, travels in the wavelength conversion member 7, and reaches the peripheral region 7b. For this reason, it is possible to increase the amount of light irradiated to a portion located obliquely above the light emitting device 1 on the irradiation surface.

Also, for the light that travels through the wavelength conversion member 7 and reaches the peripheral region 7b, the incident angle to the peripheral region 7b can be easily reduced because the peripheral region 7b is a convex curved surface. Therefore, reflection of light in the peripheral region 7b can be suppressed, and the amount of light irradiated to a portion located obliquely above the light emitting device 1 on the irradiation surface can be increased. Therefore, it is possible to reduce the variation in the amount of light applied to the portion located on the irradiation surface immediately above the light emitting device 1 and the amount of light applied to the portion located on the irradiation surface obliquely above the light emitting device 1.

In the light emitting device 1 of the present embodiment, an insulating substrate is used as the base 3. Examples of the material for the insulating substrate include a ceramic material typified by alumina and mullite, or a glass ceramic material. Further, a composite material obtained by mixing a plurality of materials among these materials may be used. Further, a polymer resin in which fine particles of metal oxide are dispersed can be used as the material of the substrate 3. By dispersing the fine particles, it becomes easy to adjust the thermal expansion of the base 3 and to adjust the thermal conductivity. As the size of the substrate 3, for example, in the case of a flat plate shape, one side can be set to 2 mm or more and 20 mm or less. Moreover, as thickness of the base | substrate 3, it can set to 0.2 mm or more and 2 mm or less, for example.

A wiring conductor (not shown) that electrically connects the inside and outside of the base 3 is formed on the base 3. The wiring conductor contains a conductive material typified by tungsten, molybdenum, manganese, or copper. The wiring conductor is obtained, for example, by printing a metal paste obtained by adding an organic solvent to a powder such as tungsten on a ceramic green sheet serving as the base 3 in a predetermined pattern and firing together with the ceramic green sheet. A plating layer (not shown) such as nickel or gold is deposited on the surface of the wiring conductor exposed inside and outside the base 3 to prevent oxidation.

In addition, the upper surface of the base 3 is made of a metal material such as aluminum, silver, gold, copper, or platinum with a space between the wiring conductor and the plating layer in order to efficiently reflect light above the base 3. A metal reflective layer may be formed. In addition, for example, an insulating transparent member such as a silicone resin containing white ceramic powder is applied to a portion of the upper surface of the substrate 3 excluding a portion where the light emitting element 5 is mounted to form a reflective layer. May be. As a result, light emitted downward from the light emitting element 5 is diffusely reflected upward on the upper or lower surface of the reflective layer, so that the light emission efficiency can be increased.

A plurality of light emitting elements 5 are mounted on the substrate 3. Specifically, the plurality of light emitting elements 5 are electrically connected to the plating layer deposited on the surface of the wiring conductor formed on the substrate 3 via, for example, a brazing material or solder. In addition, although the light-emitting device 1 of this embodiment is provided with the some light emitting element 5, even if it is the structure provided with only one light emitting element 5, there is no problem.

The light emitting element 5 has a translucent base and an optical semiconductor layer formed on the translucent base. The light-transmitting substrate may be any substrate that can grow an optical semiconductor layer using a chemical vapor deposition method such as a metal organic chemical vapor deposition method or a molecular beam epitaxial growth method. As a material used for the translucent substrate, for example, sapphire, gallium nitride, aluminum nitride, zinc oxide, zinc selenide, silicon carbide, silicon, or zirconium diboride can be used. In addition, what is necessary is just to let the thickness of a translucent base | substrate be 50 micrometers or more and 1000 micrometers or less, for example.

The optical semiconductor layer includes a first semiconductor layer formed on the translucent substrate, a light emitting layer formed on the first semiconductor layer, and a second semiconductor layer formed on the light emitting layer. Yes.

The first semiconductor layer, the light emitting layer, and the second semiconductor layer are, for example, a group III nitride semiconductor, a group III-V semiconductor such as gallium phosphide or gallium arsenide, or a group III such as gallium nitride, aluminum nitride, or indium nitride. A group nitride semiconductor or the like can be used. The thickness of the first semiconductor layer is, for example, 1 μm to 5 μm, the thickness of the light emitting layer is, for example, 25 nm to 150 nm, and the thickness of the second semiconductor layer is, for example, 50 nm to 600 nm. Good. The light emitting element 5 configured as described above can be used as an element that emits excitation light in a wavelength range of, for example, 370 nm to 420 nm.

The light emitting device 1 of the present embodiment includes a frame body 9 disposed on the main surface of the base 3 so as to surround the light emitting element 5. The frame body 9 is made of a ceramic material having the same composition as the base body 3, and is laminated on the upper surface of the base body 3 and integrally fired. The frame body 9 is provided so as to surround the light emitting element 5 on the base 3. If the shape of the inner wall surface of the frame 9 is circular in plan view, the light emitted from the light emitting element 5 can be uniformly reflected in all directions and radiated to the outside very uniformly. Further, the frame body 9 may be bonded to the upper surface of the base 3.

As the size of the frame 9, for example, the diameter of the outer wall surface in a plan view can be set to 2 mm or more and 20 mm or less, and the diameter of the inner wall surface can be set to 1 mm or more and 19 mm or less. The thickness of the frame 9 in the height direction can be set to 1 mm or more and 10 mm or less. The thickness between the inner wall surface and the outer wall surface of the frame 9 is preferably 0.5 mm or more even at the thinnest place.

The frame body 9 may be made of a porous material formed by sintering a ceramic material such as aluminum oxide, titanium oxide, zirconium oxide or yttrium oxide in a desired shape. When the frame body 9 is made of the above porous material, the reflectance of the light emitted from the light emitting element 5 on the surface of the frame body 9 is prevented from being reduced, and the frame body 9 is mechanically used for a long time. Reduction of the strength is suppressed.

When the frame body 9 is made of a porous material, a part of the joining member 11 described later is easily impregnated inside the frame body 9. Therefore, the joining member 11 can be joined and fixed to the frame body 9 more firmly. In addition, the wavelength conversion member 7 can be more firmly bonded and fixed to the frame body 9 via the bonding member 11.

When the light emitting device 1 of the present embodiment is viewed in cross section, the inner wall surfaces of the frame body 9 facing each other are inclined so that the interval between the inner wall surfaces facing each other increases from the lower side to the upper side. Further, on the inclined inner wall surface of the frame body 9, for example, a metal layer made of tungsten, molybdenum, copper or silver, and a plating layer made of nickel or gold covering the metal layer may be formed. This plating layer has a function of efficiently reflecting the light emitted from the light emitting element 5.

The inclination angle of the inner wall surface of the frame body 9 is set to an angle of, for example, 55 degrees or more and 70 degrees or less with respect to the upper surface of the base 3. The surface roughness of the plating layer is set such that the arithmetic average roughness Ra is, for example, 1 μm or more and 3 μm or less.

Further, a step 9 a is provided inside the upper end of the frame body 9. The step 9 a of the frame body 9 is for supporting the wavelength conversion member 7. The step 9a is a part of the upper portion of the frame body 9 cut out inward, and can support the end of the wavelength conversion member 7. Note that a plating layer may be formed up to the surface of the step 9a. As the size of the step 9a, the width in the height direction is set to 0.5 mm or more and 3 mm or less, and the width in the thickness direction of the frame body 9 (lateral direction in FIG. 2) is set to 0.3 mm or more and 3 mm or less. Can do.

When light from the light emitting element 5 is wavelength-converted by the wavelength conversion member 7, heat is generated inside the wavelength conversion member 7 due to conversion loss. When the wavelength conversion member 7 and the plating layer are in contact with each other by forming the plating layer up to the surface of the step 9a, the heat generated in the wavelength conversion member 7 is applied to the frame body 9 in the plating layer. It becomes easy to dissipate heat through. By making the heat dissipation of the heat generated inside the wavelength conversion member 7 favorable, it is possible to suppress the wavelength conversion efficiency and transmittance of the wavelength conversion member 7 from being lowered. Moreover, it can suppress that the mechanical strength of the wavelength conversion member 7 falls.

The wavelength conversion member 7 in this embodiment is disposed above the light emitting element 5. Specifically, the wavelength conversion member 7 is positioned above the light emitting element 5 so as to face the light emitting element 5 with a gap. The wavelength conversion member 7 has a flange-shaped portion on the outer peripheral portion thereof and outside the peripheral portion 7e. The wavelength conversion member 7 is positioned on the frame body 9, and the collar-shaped part is supported by the frame body 9. The wavelength conversion member 7 has an inner surface facing the light emitting element 5 and an outer surface located on the side opposite to the inner surface.

The inner surface of the wavelength conversion member 7 has a concave curved shape. When the inner surface has a concave dome shape as compared with the case where the inner surface has a flat shape, the light emitted from the light emitting element 5 and incident on the wavelength converting member 7 is reflected on the inner surface of the wavelength converting member 7. Since it is difficult to reflect, more light can enter the wavelength conversion member 7.

The wavelength conversion member 7 is a member for converting the wavelength of at least a part of the light emitted from the light emitting element 5 and radiating it outside. Examples of the wavelength conversion member 7 include those containing a phosphor. Light emitted from the light emitting element 5 is incident on the inside of the wavelength conversion member 7, and the phosphor contained in the wavelength conversion member 7 is excited to emit wavelength-converted light.

Specifically, the wavelength conversion member 7 is made of a silicone resin, an acrylic resin, or an epoxy resin, and a configuration in which a phosphor is contained in the resin can be given as an example. Further, as a phosphor, a blue phosphor emitting fluorescence of 430 nm to 490 nm, a green phosphor emitting fluorescence of 500 nm to 560 nm, a yellow phosphor emitting fluorescence of 540 nm to 600 nm, or a fluorescence of 590 nm to 700 nm An example is one containing a red phosphor that emits.

Further, the phosphor is uniformly dispersed in the wavelength conversion member 7. The thermal conductivity of the wavelength conversion member 7 is set to, for example, 0.10 W / (m · K) or more and 0.30 W / (m · K) or less. As the size of the wavelength conversion member 7, for example, as shown in FIG. 1, the diameter can be set to 1 mm or more and 18 mm or less when the shape is circular when viewed in plan. The thickness of the wavelength conversion member 7 is set such that the smallest thickness portion is 0.7 mm or more and the thickest portion is 3 mm or less.

Although the resin member containing a phosphor is shown as an example of the wavelength conversion member 7, the wavelength conversion member 7 is not limited to the above configuration. For example, a light scattering agent such as titanium oxide or zinc oxide, or a phosphorescent material such as an iridium complex may be used in place of the phosphor described above. Further, instead of the resin member containing the phosphor, an oxide glass-based or fluorophosphate glass-based fluorescent glass using Eu ³⁺ as a fluorescent medium may be used.

The light emitting device 1 of the present embodiment has a plurality of light emitting elements 5. When the wavelength conversion member 7 is seen through, it is preferable that each light emitting element 5 overlaps the wavelength conversion member 7 in the central region 7a. The light emitted from each light emitting element 5 in the directly upward direction is easily reflected in the flat central region 7a, and the light emitted obliquely above the region where the plurality of light emitting elements 5 are disposed is a convex curved surface. It is because it becomes difficult to reflect in the peripheral area | region 7b which is a shape.

When the wavelength conversion member 7 is viewed in a cross section passing through the light emitting element 5 perpendicular to the main surface of the substrate 3, the flat surface portion, that is, the thickness T1 in the central portion 7d has a convex curved surface portion, that is, a peripheral edge. It is preferable that the thickness is larger than the thickness T2 in the portion 7e. Specifically, when the wavelength conversion member 7 is viewed in a cross section through the light emitting element 5 perpendicular to the main surface of the substrate 3, the thickness T1 at the smallest thickness in the central portion 7d is the thickness in the peripheral portion 7e. The thickness is preferably larger than the thickness T2 at the smallest portion. In particular, the ratio T1 / T2 between the thickness T1 in the central portion 7d and the thickness T2 in the peripheral portion 7e is more preferably about 1.2 to 5.

When the light-emitting element 5 has a laminated structure having a light-transmitting substrate and an optical semiconductor layer formed on the light-transmitting substrate as in this embodiment, the light emitted from the light-emitting element 5 is directly above the diagonally upper side. A relatively large amount of radiation is emitted. Therefore, more light is incident on the central portion 7 d of the wavelength conversion member 7 positioned in the direction immediately above the light emitting element 5 than the peripheral portion 7 e around the central portion 7 d and close to the frame body 9. When the thickness T1 in the central portion 7d is larger than the thickness T2 in the peripheral portion 7e, the light is emitted from the light emitting element 5 efficiently in the central portion 7d where relatively more light is incident as compared with the peripheral portion 7e. The wavelength conversion of the primary light can be performed. Therefore, the light emission efficiency of the light emitting device 1 can be improved.

Further, when the wavelength converting member 7 is viewed in a cross section passing through the light emitting element 5 perpendicular to the main surface of the substrate 3, the thickness T1 of the central portion in the central portion 7d is larger than the thickness T3 of the peripheral end portion in the central portion 7d. Is preferably small. Thereby, the durability of the wavelength conversion member 7 can be enhanced. In particular, the ratio T1 / T3 between the thickness T1 at the center and the thickness T3 at the peripheral edge is more preferably about 0.2 to 0.8.

As described above, the light emitted from the light emitting element 5 enters the inside of the wavelength conversion member 7, the phosphor contained in the wavelength conversion member 7 is excited, and the light whose wavelength is converted from the phosphor Radiated. At this time, since the wavelength conversion member 7 generates heat due to the loss of wavelength conversion, the wavelength conversion member 7 is thermally expanded. In the wavelength conversion member 7 of the present embodiment, thermal stress caused by this thermal expansion tends to concentrate on the boundary portion between the central region 7a and the peripheral region 7b having different outer surface shapes. However, when the thickness T1 of the central portion in the central portion 7d is smaller than the thickness T3 of the peripheral end portion in the central portion 7d as in the wavelength conversion member 7 in the present embodiment, the strength of the boundary portion is increased. Therefore, the boundary portion can be prevented from being greatly deformed or broken.

In addition, since light is likely to be multiple-reflected in the vicinity of the boundary portion between the central region 7a and the peripheral region 7b, the light loss at the boundary portion is likely to increase. However, since the thickness T1 of the central portion in the central portion 7d is smaller than the thickness T3 of the peripheral end portion in the central portion 7d, the amount of the phosphor existing in the vicinity of the boundary portion can be increased. As a result, light emission from the center portion 7d is increased, and unevenness in light emission between the central portion of the central portion 7d and the peripheral end portion of the central portion 7d can be reduced.

Further, the end of the wavelength conversion member 7 is positioned on the step 9 a of the frame 9, and the end of the wavelength conversion member 7 is surrounded by the frame 9. The light that has entered the wavelength conversion member 7 from the light emitting element 5 may reach the end within the wavelength conversion member 7. However, the reflected light can be returned into the wavelength conversion member 7 again by reflecting the light traveling from the end of the wavelength conversion member 7 toward the frame body 9 with the frame body 9. As a result, the phosphor is excited by the light that has returned to the wavelength conversion member 7 again, so that the light output of the light emitting device 1 can be improved.

The wavelength conversion member 7 has a concave curved surface on the inner surface where the curvature of the convex curved surface, that is, the curvature of the peripheral region 7b on the outer surface, when viewed in cross section through the light emitting element 5 perpendicular to the main surface of the substrate 3. It is preferable that the curvature is smaller than the curvature. In other words, it is preferable that the radius of curvature of the peripheral region 7b on the outer surface is larger than the radius of curvature of the inner surface. In particular, the ratio of the radius of curvature of the peripheral region 7b on the outer surface to the radius of curvature of the inner surface is more preferably about 1.1 to 2.0.

The end of the wavelength conversion member 7 is bonded and fixed to the step 9 a of the frame body 9 via a translucent bonding member 11. At this time, the bonding member 11 is bonded to the side surface, the upper surface, and the lower surface of the wavelength conversion member 7. In such a case, the possibility that the wavelength conversion member 7 peels from the bonding member 11 can be suppressed.

The thermal conductivity of the bonding member 11 is set to be larger than the thermal conductivity of the wavelength conversion member 7. The bonding member 11 is formed from the end position on the upper surface of the wavelength conversion member 7 to the end position on the lower surface of the wavelength conversion member 7. The joining member 11 is made of a translucent insulating resin such as a silicone resin, an acrylic resin, or an epoxy resin. Of the above members, it is preferable to use a silicone resin as the bonding member 11. This is because light of a short wavelength can be transmitted satisfactorily and the deterioration of transmittance due to light energy is small. In particular, when the wavelength of the light-emitting element 5 is 450 nm or less, a decrease in transmittance due to light energy is large, and therefore it is desirable to use a silicone resin as the wavelength conversion member 7.

Further, it is preferable that the joining member 11 includes a member constituting the wavelength conversion member 7. This is because the bondability between the bonding member 11 and the wavelength conversion member 7 can be improved. Moreover, since the difference between the thermal expansion coefficient of the joining member 11 and the thermal expansion coefficient of the wavelength conversion member 7 can be reduced, the joining of the joining member 11 and the wavelength conversion member 7 due to the difference in thermal expansion of these members. Stress generated on the surface can be reduced. The thermal conductivity of the joining member 11 is set to, for example, 0.14 W / (m · K) or more and 4.0 W / (m · K) or less.

The light emitting device 1 of the present embodiment further includes a light-transmitting sealing member 13 disposed on the light emitting element 5 between the light emitting element 5 and the wavelength conversion member 7. In other words, the translucent sealing member 13 is disposed on the light emitting element 5, and the wavelength conversion member 7 is disposed above the translucent sealing member 13. The sealing member 13 has a function of sealing the light emitting element 5 and transmitting light emitted from the light emitting element 5. The sealing member 13 is a region surrounded by the frame body 9 in a state where the light emitting element 5 is accommodated inside the frame body 9, and is filled up to a position lower than the height position of the step 9a. Therefore, there is a gap between the wavelength conversion member 7 and the sealing member 13 in the present embodiment.

It is preferable that at least a portion of the upper surface of the sealing member 13 positioned immediately above the light emitting element 5 is a plane parallel to the upper surface of the light emitting element 5. The light emitted from the upper surface of the light emitting element 5 and traveling inside the sealing member 13 and reaching the upper surface of the sealing member 13 is incident at an acute angle with respect to the upper surface of the sealing member 13. Reflecting on the upper surface of 13 is suppressed, and it becomes easy to radiate above the sealing member 13.

Furthermore, it is preferable that the entire upper surface of the sealing member 13 is a plane parallel to the upper surface of the light emitting element 5. When a gap is formed above the sealing member 13, the light is refracted to the side of the light emitting element 5 when proceeding from the sealing member 13 to the gap. Thereby, since the amount of light incident on the peripheral portion of the wavelength conversion member 7 can be increased, the light incident on the central portion 7d of the wavelength conversion member 7 and the light incident on the peripheral portion 7e of the wavelength conversion member 7 The variation of can be reduced. As a result, light emission unevenness in the wavelength conversion member 7 can be further suppressed.

It should be noted that the fact that the upper surface of the sealing member 13 is a plane parallel to the upper surface of the light emitting element 5 does not mean that it is strictly a planar shape. For example, if the top surface of the sealing member 13 inevitably occurs in the manufacturing process, and the side end surface of the sealing member 13 is joined to the inner peripheral surface of the frame body 9, sealing is performed. Some concave shape or convex shape is unavoidably generated at the side end portion of the sealing member 13 due to the wettability between the stop member 13 and the frame body 9.

Further, it is preferable that at least a part of the bonding member 11 is exposed to the gap between the wavelength conversion member 7 and the sealing member 13. This is because it is possible to increase the possibility that the light incident on the bonding member 11 is reflected upward on the surface of the bonding member 11 exposed in the gap having a refractive index smaller than that of the bonding member 11. Therefore, it is possible to reduce light loss caused by entering the sealing member 13 from the joining member 11 and repeating irregular reflection inside the light emitting device 1. Furthermore, the light traveling on the surface exposed to the gap of the bonding member 11 is easily reflected upward, and the light emitted to the outside of the light emitting device 1 through the upper surface of the bonding portion can be increased. As a result, the light emission efficiency of the light emitting device 1 can be increased.

Moreover, the sealing member 13 has a function of absorbing heat caused by photoelectric conversion of the light emitting element 5 and diffusing in the sealing member 13. Further, heat caused by light emitted from the light emitting element 5 is transmitted to the base 3 and the frame body 9 through the sealing member 13, so that the heat is easily diffused throughout the light emitting device 1. If heat concentrates at a specific location in the sealing member 13, the thermal expansion of the sealing member 13 becomes extremely large locally, and the sealing member 13 may be peeled off from the base 3. Further, when heat concentration occurs in the sealing member 13, the light emitting element 5 becomes high temperature, the wavelength of light emitted from the light emitting element 5 changes, and the emission color of the light emitting element 5 may greatly deviate from the desired light color. Occurs. In addition, as the sealing member 13, translucent insulating resin like a silicone resin, an acrylic resin, or an epoxy resin is used, for example. The thermal conductivity of the sealing member 13 is set to, for example, 0.14 W / (m · K) or more and 0.40 W / (m · K) or less.

Next, the light emitting device of the second embodiment will be described in detail with reference to the drawings. In addition, in each structure concerning this embodiment, about the structure which has the same function as 1st Embodiment, the same referential mark is attached and the detailed description is abbreviate | omitted.

As shown in FIG. 3, the light emitting device 1 of the second embodiment includes a wavelength conversion member 7 disposed on the light emitting element 5 similarly to the light emitting device 1 of the first embodiment. In the light emitting device 1 of the first embodiment, corners are formed at the boundary between the flat surface (center region 7a) and the convex curved surface (peripheral region 7b) of the wavelength conversion member 7, but in this embodiment. In the light emitting device 1, the peripheral region 7b of the wavelength conversion member 7 is smoothly connected to the central region 7a. In other words, no corner is formed at the boundary between the central region 7a and the peripheral region 7b of the wavelength conversion member 7.

As shown in the first embodiment, when a corner is formed at the boundary between the central region 7a and the peripheral region 7b of the wavelength conversion member 7, light is likely to be multiple-reflected in the vicinity of the boundary. However, in the wavelength conversion member 7 of the present embodiment, since the central region 7a and the peripheral region 7b are smoothly connected, the light emission from the wavelength conversion member 7 at the boundary between the central region 7a and the peripheral region 7b. Can be prevented from changing rapidly. Therefore, the light emission unevenness at the boundary portion can be reduced. Furthermore, since the stress generated in the wavelength conversion member 7 is not concentrated on the corner portion but is distributed around the corner portion, cracks and cracks generated due to the stress are suppressed, and the light emitting device 1 is long. Can operate normally over a period of time.

In the light emitting device 1 of the present embodiment, the central region 7a and the peripheral region 7b are smoothly connected to each other in that the boundary portion between the central region 7a and the peripheral region 7b is strictly smoothly connected. However, there is no problem even if a corner having a size of irregularities inevitably generated in the manufacturing process is formed on the outer surface of the wavelength conversion member 7 at the boundary between the central region 7a and the peripheral region 7b. For example, when the outer surface of the wavelength conversion member 7 is visually observed, the effect of the present embodiment can be sufficiently obtained as long as the boundary portion between the central region 7a and the peripheral region 7b cannot be visually recognized.

Next, the light emitting device of the third embodiment will be described in detail with reference to the drawings. In addition, in each structure concerning this embodiment, about the structure which has the same function as 1st Embodiment, the same referential mark is attached and the detailed description is abbreviate | omitted.

As shown in FIG. 4, the light emitting device 1 according to the third embodiment includes a wavelength conversion member 7 disposed on the light emitting element 5, similarly to the light emitting device 1 according to the first embodiment. Moreover, the inner surface (the lower surface in FIG. 4) facing the light emitting element 5 in the wavelength conversion member 7 is a concave curved surface.

The wavelength conversion member 7 has a central portion 7d including a region overlapping with the light emitting element 5 and a peripheral portion 7e positioned so as to surround the central portion 7d when seen in a plan view. The outer surface of the wavelength conversion member 7 has a central region 7a including a region overlapping the light emitting element 5 and a peripheral region 7b positioned so as to surround the central region 7a when seen through on a plane.

At this time, in the wavelength conversion member 7 in the light emitting device 1 of the first embodiment, the central region 7a is a flat surface and the peripheral region 7b is a convex curved surface, but the wavelength in the light emitting device 1 of the present embodiment. In the conversion member 7, the center area | region 7a and the peripheral area | region 7b are convex curved surfaces, respectively. However, in the cross section perpendicular to the main surface of the substrate 3, the curvature of the central region 7 a is smaller than the curvature of the peripheral region 7 b and the curvature of the inner surface, and the outer surface is similar to the light emitting device 1 of the first embodiment. The central portion 7d, which is the central region 7a, functions as a concave lens, and the peripheral portion 7e, whose outer surface is the peripheral region 7b, functions as a convex lens.

As described above, like the light emitting device 1 of the first embodiment, since the central portion 7d functions as a concave lens, the light emitted from the central region 7a can be efficiently dispersed obliquely above the light emitting device 1. it can. Therefore, it is possible to reduce the variation in the amount of light irradiated to the portion located directly above the light emitting device 1 on the irradiation surface and the amount of light irradiated to the portion positioned obliquely above the light emitting device 1 on the irradiation surface.

In the light emitting device 1 of the present embodiment, the curvature of the central region 7a is smaller than the curvature of the peripheral region 7b and the curvature of the inner surface. This is because the curvature radius of the central region 7a is the curvature radius of the peripheral region 7b and the curvature of the inner surface. In other words, it is larger than the radius. In particular, the ratio of the radius of curvature of the central region 7a to the radius of curvature of the peripheral region 7b and the ratio of the radius of curvature of the central region 7a to the radius of curvature of the inner surface are about 1.1 to 2.0, respectively. preferable.

Next, the light emitting device of the fourth embodiment will be described in detail with reference to the drawings. In addition, in each structure concerning this embodiment, about the structure which has the same function as 1st Embodiment, the same referential mark is attached and the detailed description is abbreviate | omitted.

As shown in FIG. 5, the light emitting device 1 of the fourth embodiment includes a wavelength conversion member 7 disposed on the light emitting element 5, similarly to the light emitting device 1 of the first embodiment. Further, the inner surface (the lower surface in FIG. 5) facing the light emitting element 5 in the wavelength conversion member 7 is a concave curved surface.

The wavelength conversion member 7 has a central portion 7d including a region overlapping with the light emitting element 5 and a peripheral portion 7e positioned so as to surround the central portion 7d when seen in a plan view. The outer surface of the wavelength conversion member 7 has a central region 7a including a region overlapping the light emitting element 5 and a peripheral region 7b positioned so as to surround the central region 7a when seen through on a plane.

At this time, in the wavelength conversion member 7 in the light emitting device 1 of the first embodiment, the central region 7a is a flat surface and the peripheral region 7b is a convex curved surface, but the wavelength in the light emitting device 1 of the present embodiment. In the conversion member 7, the central region 7a is a concave curved surface, and the peripheral region 7b is a convex curved surface.

The first region is not only when the central region 7a is a flat surface as in the light emitting device 1 of the first embodiment, but also when the central region 7a is a concave curved surface as in the light emitting device 1 of the present embodiment. Similar to the light emitting device 1 of the embodiment, the central portion 7d whose outer surface is the central region 7a functions as a concave lens, and the peripheral portion 7e whose outer surface is the peripheral region 7b functions as a convex lens.

Thus, like the light emitting device 1 of the first embodiment, since the central portion 7d functions as a concave lens, the light emitted from the central region 7a can be efficiently dispersed obliquely above the light emitting device 1. it can. Therefore, it is possible to reduce the variation in the amount of light irradiated to the portion located directly above the light emitting device 1 on the irradiation surface and the amount of light irradiated to the portion positioned obliquely above the light emitting device 1 on the irradiation surface.

Further, as compared with the light emitting device 1 of the first embodiment, when the central region 7a is a concave curved surface, more light emitted from the central region 7a is distributed obliquely above the light emitting device 1. Can do. Therefore, more light can be irradiated to the portion located obliquely above the light emitting device 1 on the irradiation surface. The light emitting device 1 of the present embodiment is particularly effective when it is desired to irradiate more light on a portion of the irradiation surface located obliquely above the light emitting device 1 than on the portion of the irradiation surface located immediately above the light emitting device 1. Become.

Next, the light emitting device of the fifth embodiment will be described in detail with reference to the drawings. In addition, in each structure concerning this embodiment, about the structure which has the same function as 1st Embodiment, the same referential mark is attached and the detailed description is abbreviate | omitted.

As shown in FIG. 6, the light emitting device 1 according to the fifth embodiment includes a wavelength conversion member 7 disposed on the light emitting element 5, similarly to the light emitting device 1 according to the first embodiment. And the wavelength conversion member 7 in this embodiment has the several recessed part 7c in the outer surface. In the light emitting device 1 of the present embodiment, when the outer surface of the wavelength conversion member 1 is seen in a plane, a region including a region overlapping the light emitting element and excluding a portion where the recess 7c is formed is a central region. A region that is located so as to surround the central region and has a convex curved surface except for a portion where the concave portion 7c is formed is defined as a peripheral region.

Although it is possible to increase the surface area of the wavelength conversion member 7 simply by increasing the wavelength conversion member 7, the volume of the wavelength conversion member 7 also increases in such a case, and thus the amount of light absorbed by the wavelength conversion member 7. Will also increase. Therefore, it becomes difficult to improve the light emission efficiency. Further, not only the surface of the wavelength conversion member 7 facing the outside of the light emitting device 1 but also the area of the surface facing the inside of the light emitting device 1 including the inner surface facing the light emitting element 5 is increased. Therefore, it becomes difficult to efficiently extract the light whose wavelength has been converted inside the wavelength conversion member 7 to the outside.

On the other hand, in the light emitting device 1 according to the present embodiment, the wavelength conversion member 7 has a concave inner surface and a plurality of concave portions 7c on the outer surface. The surface area of the surface of the conversion member 7 can be increased. For this reason, light that has been wavelength-converted inside the wavelength conversion member 7 can easily be emitted to the outside while making a large amount of light enter the wavelength conversion member 7, so that the light emission efficiency of the light-emitting device 1 can be improved.

The width of the recess 7c can be set to 0.4 mm to 4 mm, for example. In the present embodiment, the width of the recess 7c means the length of one side when the shape of the opening of the recess 7c is rectangular, and the shape of the opening of the recess 7c is oval. Means the major axis. The depth of the recess 7c can be set to 0.3 mm to 1.5 mm, for example.

Next, the light emitting device of the sixth embodiment will be described in detail with reference to the drawings. In addition, in each structure concerning this embodiment, about the structure which has the same function as 1st Embodiment, the same referential mark is attached and the detailed description is abbreviate | omitted.

As shown in FIG. 7, the light emitting device 1 according to the sixth embodiment includes a wavelength conversion member 7 disposed on the light emitting element 5, similarly to the light emitting device 1 according to the first embodiment. The light emitting device 1 according to the first embodiment includes a frame body 9 disposed on the main surface of the base 3 so as to surround the light emitting element 5. The light emitting device 1 according to the present embodiment includes the frame 9. The frame 9 is not provided, and the wavelength conversion member 7 is directly bonded to the base 3 via an adhesive (not shown). There is no problem even if the wavelength conversion member 7 is not directly provided with the frame body 9 and the wavelength conversion member 7 is directly bonded to the base 3 via an adhesive as in the light emitting device 1 of the present embodiment.

As the adhesive, an insulating resin such as a silicone resin, an acrylic resin, or an epoxy resin can be used in the same manner as the bonding member 11. In addition, although the translucent member is used as the joining member 11, in order to suppress that the emitted light from the light emitting element 5 before wavelength conversion leaks directly as an adhesive agent, it is colored like black It is preferable to use this member.

Next, a method for manufacturing the light emitting device 1 according to the above embodiment will be described.

First, the base 3 and the frame 9 are prepared. When the base body 3 and the frame body 9 are made of, for example, an aluminum oxide sintered body, an organic binder, a plasticizer and a solvent are added to and mixed with a raw material powder such as aluminum oxide, silicon oxide, magnesium oxide or calcium oxide. Get. In the sixth embodiment, only the base 3 needs to be prepared.

Then, the mixture of the base 3 and the frame 9 is filled with the mixture and dried, and then the base 3 and the frame 9 before sintering are taken out.

Also, a high melting point metal powder such as tungsten or molybdenum is prepared, and an organic binder, a plasticizer, a solvent, or the like is added to and mixed with the powder to obtain a metal paste. And it prints with the predetermined pattern on the ceramic green sheet used as the taken-out base | substrate 3, and bakes in the state which laminated | stacked the several ceramic green sheet.

Next, a plating layer is formed on the surface of the wiring conductor exposed on the upper and lower surfaces of the substrate 3 to prevent the wiring conductor from being oxidized. Then, the light emitting element 5 is electrically connected to the plating layer via solder.

Further, the frame body 9 is sintered at a desired temperature to be a porous sintered body, and is bonded to the upper surface of the substrate 3 so as to surround the light emitting element 5 with an adhesive made of silicone resin.

Then, the sealing member 13 is formed by filling the region surrounded by the frame body 9 with, for example, silicone resin and curing the silicone resin. In the sixth embodiment, since the frame body 9 is not used, a mold frame serving as a substitute for the frame body 9 is prepared, and the region surrounded by the base body 3 and the mold frame is filled with the sealing member 13. To be formed.

Next, the wavelength conversion member 7 is prepared. The wavelength conversion member 7 can be obtained by mixing a phosphor with uncured resin, filling the uncured wavelength conversion member 7 into a mold, curing, and taking it out, for example. At this time, by forming the shape of the mold in a desired shape in advance, the wavelength conversion member 7 having the outer surface of the desired shape can be obtained. That is, a form having a shape that is formed according to the shape of the wavelength conversion member 7 in the light emitting device 1 of each embodiment may be prepared in advance.

For example, the wavelength conversion member 7 in the light emitting device 1 of the first embodiment can be manufactured as follows. The flat central region 7a including the region overlapping the light emitting element 5 formed on the outer surface of the wavelength conversion member 7 and the peripheral region 7b having a convex curved surface located so as to surround the central region 7a are formed as described above. The frame can be formed by providing a flat surface corresponding to the central region 7a and a concave curved surface corresponding to the peripheral region 7b. A flat central region 7 a corresponding to the plane of the mold and a peripheral region 7 b having a convex curved shape corresponding to the concave curved surface of the mold are formed on the outer surface of the wavelength conversion member 7.

In addition, as a molding method of the wavelength conversion member 7, a general molding method represented by injection molding, extrusion molding, hollow molding, compression molding, and thermoforming may be appropriately used. The formation of the central region 7a and the peripheral region 7b of the wavelength conversion member 7 is not limited to the above method, and the wavelength conversion member 7 may be formed by scraping off a part of the outer surface of the wavelength conversion member 7 that has been hardened and taken out.

The wavelength conversion member 7 produced by the above method is bonded onto the step 9 a of the frame body 9 via the bonding member 11. Specifically, the joining member 11 is disposed on the step 9 a of the frame body 9, and the prepared wavelength conversion member 7 is disposed on the joining member 11. Thereafter, the wavelength conversion member 7 can be bonded onto the frame body 9 via the bonding member 11 by curing the bonding member 11. At this time, an excessive bonding member 11 is disposed on the step 9 a of the frame body 9 and is disposed while pressing the wavelength conversion member 7 against the bonding member 11, whereby a part of the bonding member 11 is disposed on the wavelength conversion member 7. Can be extruded onto the top surface. As a result, the bonding member 11 can be bonded to the side surface, the upper surface, and the lower surface of the wavelength conversion member 7.

Further, after the wavelength conversion member 7 is disposed on the step 9 a of the frame body 9, the step 9 a between the wavelength conversion member 7 and the frame body 9 so that a part of the bonding member 11 is bonded to the upper surface of the wavelength conversion member 7. Also, the bonding member 11 can be bonded to the side surface, the upper surface, and the lower surface of the wavelength conversion member 7 by filling the gap between the bonding member 11 with a dispenser or the like. As described above, the light-emitting device 1 of the above-described embodiment can be manufactured.

Next, a lighting device according to an embodiment of the present invention will be described.

As shown in FIG. 8, the illumination device 15 of the present embodiment includes a light emitting device 1 typified by the above embodiment, a mounting plate 17 on which the light emitting device 1 is mounted, and an electrical wiring 19 that energizes the light emitting device 1. And a light reflecting means 21 for reflecting the light emitted from the light emitting device 1.

The light emitting device 1 in the lighting device 15 of the present embodiment is placed on the mounting plate 17. At this time, as shown in FIG. 8, since the illumination device 15 of the present embodiment is formed so as to illuminate the lower part, the light-emitting device 1 is arranged so that the light-emitting element 5 is positioned below the base 3. And placed on the mounting plate 17. In the illumination device 15 of the present embodiment, light is emitted from the light emitting device 1 by energizing the light emitting device 1 through the electrical wiring 19. And it functions as the illuminating device 15 which illuminates a desired direction by reflecting said emitted light by the light reflection means 21.

The lighting device 15 may include only one light emitting device 1 or may include a plurality of light emitting devices 1 as shown in FIG. Further, when a plurality of light emitting devices 1 are provided, the light emitting devices 1 may be arranged in series or in parallel by the electric wiring 19.

Note that the present invention is not limited to the above-described embodiment, and various modifications may be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Light-emitting device 3 ... Base | substrate 5 ... Light-emitting element 7 ... Wavelength conversion member 7a ... Central area | region 7b ... Peripheral area | region 7c ... Recess 9 ... Frame 9a ... · Step 11 · · · Joining member 13 · · · Sealing member 15 · · · Lighting device 17 · · · Mounting plate 19 · · · Electrical wiring 21 · · · Light reflecting means

Claims (7)

A substrate;
A light emitting device disposed on the main surface of the substrate;
A wavelength conversion member having an inner surface facing the light emitting element and an outer surface opposite to the inner surface;
The inner surface is a concave curved surface;
The outer surface has a flat surface and a convex curved surface positioned so as to surround the flat surface,
The light-emitting device, wherein the flat surface is positioned so as to overlap the light-emitting element when viewed through. The light emitting device according to claim 1, wherein the convex curved surface is smoothly connected to the flat surface. The wavelength converting member is characterized in that the thickness of the flat surface portion is larger than the thickness of the convex curved surface portion when viewed in cross section through the light emitting element perpendicular to the main surface of the substrate. The light emitting device according to claim 1. The wavelength conversion member is characterized in that the curvature of the convex curved surface is smaller than the curvature of the concave curved surface when viewed in a cross section passing through the light emitting element perpendicular to the main surface of the substrate. Item 4. The light emitting device according to Item 1. The light-emitting device according to claim 1, further comprising a translucent sealing member disposed between the light-emitting element and the wavelength conversion member on the light-emitting element. A substrate;
A light emitting device disposed on the main surface of the substrate;
A wavelength conversion member having an inner surface facing the light emitting element,
The inner surface is a concave curved surface;
The wavelength converting member has a central portion forming a concave lens and a peripheral portion forming a convex lens positioned so as to surround the central portion;
The light emitting device, wherein the central portion is positioned so as to overlap the light emitting element when seen through in plan view. The light-emitting device according to any one of claims 1 to 6, a mounting plate on which the light-emitting device is mounted, an electrical wiring for energizing the light-emitting device, and a light reflecting means for reflecting light emitted from the light-emitting device And a lighting device.

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