JP2017034179A - Light-emitting module - Google Patents

Abstract

A novel light emitting module with high color rendering properties is provided. A light emitting module includes a light emitting element that emits ultraviolet light or short wavelength visible light, and a light wavelength conversion layer that emits visible light when excited by light emitted from the light emitting element. The light wavelength conversion layer 18 includes a first layer 20 and a second layer 22 provided on the opposite side of the light emitting element with the first layer 20 interposed therebetween. The first layer 20 and the second layer 22 include a red phosphor 24, a green phosphor 26, a yellow phosphor 30 and a blue phosphor 32. The first layer 20 includes at least one of a red phosphor 24 and a green phosphor 26. The second layer 22 includes at least one of a yellow phosphor 30 and a blue phosphor 32. [Selection] Figure 1

Description

  The present invention relates to a light emitting module.

  Conventionally, a white light source using an LED has been devised. For example, a blue light emitting diode mounted on the bottom surface of a cup-shaped recess, and a transparent resin portion in which two or more kinds of phosphors filled in the recess and excited by blue light to emit visible light other than blue are dispersed Has been devised (see Patent Document 1). The transparent resin portion of the light emitting device is composed of at least two layers having different phosphors, and a red phosphor having a relatively wide excitation spectrum is contained in the lower layer provided on the bottom surface side of the recess. The yellow phosphor having a relatively narrow excitation spectrum is contained in the upper layer provided on the opening side of the recess.

  In addition, the light emitting device includes a light emitting element that emits excitation light in a wavelength range of 370 nm to 420 nm on a substrate, and a wavelength conversion layer that converts the excitation light formed so as to cover the light emitting element into visible light. In the wavelength conversion layer, 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, and a fluorescence of 590 nm to 700 nm A light emitting device including a red phosphor that emits light has been devised (see Patent Document 2). In this light emitting device, a yellow phosphor and a red phosphor are contained in a second layer closer to the light emitting element than a first layer containing a blue phosphor and a green phosphor.

  Also, three types of phosphor layers that are disposed on the light extraction side of the ultraviolet light emitting element and emit wavelength converted light of red light, green light, and blue light by being excited by receiving light emitted from the ultraviolet light emitting element. A plate member for wavelength conversion in which at least two phosphor layers are laminated from the light emitting element side along the light extraction side, and red light as wavelength converted light of the three phosphor layers is used. A light emitting device has been devised in which the emitted red phosphor layer is disposed closer to the ultraviolet light emitting element than other phosphor layers (see Patent Document 3).

JP 2007-81090 A JP 2007-103512 A JP 2007-134656 A

  However, the above-described light emitting device has room for further improvement from the viewpoints of chromaticity and color rendering.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a novel light emitting module having high color rendering properties.

  In order to solve the above problems, a light-emitting module according to an aspect of the present invention includes a light-emitting element that emits ultraviolet light or short-wavelength visible light, and a light wavelength conversion layer that emits visible light when excited by light emitted from the light-emitting element. . The light wavelength conversion layer includes a first layer and a second layer provided on the opposite side of the light emitting element with the first layer interposed therebetween. The first layer and the second layer include a red phosphor, a green phosphor, a yellow phosphor, and a blue phosphor. The first layer includes at least one of a red phosphor and a green phosphor. The second layer includes at least one of a yellow phosphor and a blue phosphor.

  According to this aspect, since the four phosphors having different colors of excitation light are included, a novel light emitting module with high color rendering properties can be realized. In addition, since the red phosphor or green phosphor whose excitation spectrum exists to a relatively long wavelength side is included in the first layer close to the light emitting element, yellow light or blue light excited in the second layer Re-absorption by the first layer is suppressed, and color misregistration and light flux reduction are reduced.

  The first layer may include a red phosphor and a green phosphor. The second layer may include a yellow phosphor and a blue phosphor. As a result, since the red phosphor and the green phosphor whose excitation spectrum exists to a relatively long wavelength side are included in the first layer close to the light emitting element, yellow light or blue light excited in the second layer Is suppressed by the first layer, and color misregistration and a decrease in luminous flux are reduced.

  The first layer may include a red phosphor. The second layer may include a green phosphor, a yellow phosphor and a blue phosphor. As a result, the red phosphor having an excitation spectrum up to a relatively long wavelength side is included in the first layer close to the light emitting element, so that yellow light or blue light excited in the second layer is the first. Re-absorption by the layer is suppressed, and a color shift and a decrease in luminous flux are reduced.

You may further provide the board | substrate with which a light emitting element is mounted, and the conducting wire which electrically connects a light emitting element and a board | substrate. The first layer is a first resin layer having a modulus of elasticity of 10 ⁴ to 10 ⁵ Pa in which at least any temperature included in a range of −40 to 100 ° C. in which a red phosphor and a green phosphor are dispersed. You may have. The first resin layer may be provided so as to seal the conducting wire. Thereby, the stress acting on the conductor can be relaxed.

  The second layer may include a second resin layer having a Shore A hardness of 30 to 80 in which a yellow phosphor and a blue phosphor are dispersed. Thereby, a light emitting element is protected.

 It should be noted that any combination of the above-described constituent elements and a representation of the present invention converted between a method, an apparatus, a system, etc. are also effective as an aspect of the present invention.

  According to the present invention, a novel light emitting module with high color rendering properties can be realized.

1 is a cross-sectional view schematically showing an outline of a light emitting module according to Example 1. FIG. It is a figure which shows an example of the excitation spectrum and emission spectrum of a red fluorescent substance used in an Example. It is a figure which shows an example of the excitation spectrum of the green fluorescent substance used in an Example, and an emission spectrum. It is a figure which shows an example of the excitation spectrum and emission spectrum of yellow fluorescent substance used in an Example. It is a figure which shows an example of the excitation spectrum and emission spectrum of the blue fluorescent substance used in an Example. It is the side view which showed the outline of the light emitting module which concerns on Example 2 typically. It is AA sectional drawing of the light emitting module shown in FIG. It is a figure which shows the light emission spectrum of the light emitting module which concerns on Example 1, and the light emission spectrum of the light emitting module which concerns on the comparative example 1. It is a figure which shows the emission spectrum of the light emitting module which concerns on Example 2. FIG. 6 is a cross-sectional view schematically showing an outline of a light emitting module according to Example 3. FIG. It is a figure which shows the change of the emission spectrum in the light emitting module which concerns on Example 3. FIG.

  The present invention will be described below based on preferred embodiments with reference to the drawings. The same or equivalent components, members, and processes shown in the drawings are denoted by the same reference numerals, and repeated descriptions are omitted as appropriate. Further, the embodiments do not limit the invention but are exemplifications, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention.

(Light emitting module)
The light emitting module according to this embodiment includes a light emitting element that emits ultraviolet light or short wavelength visible light, and a light wavelength conversion layer that is excited by light emitted from the light emitting element and emits visible light. The light wavelength conversion layer includes a first layer and a second layer provided on the opposite side of the light emitting element with the first layer interposed therebetween. The first layer and the second layer include a red phosphor, a green phosphor, a yellow phosphor, and a blue phosphor. The first layer includes at least one of a red phosphor and a green phosphor. The second layer includes at least one of a yellow phosphor and a blue phosphor.

(Light emitting element)
The emission spectrum of the light-emitting element according to this embodiment is not particularly limited as long as it emits at least ultraviolet light or short-wavelength visible light, but from the viewpoint of the light emission efficiency of the light-emitting device, the peak of the emission spectrum. Is preferably in the wavelength region of 350 nm to 430 nm.

  Further, as specific examples of the light emitting element, for example, various light sources such as a semiconductor light emitting element such as an LED, an LD, and an EL, a light source for obtaining light emission from vacuum discharge or thermoluminescence, and an electron beam excitation light emitting element are used. it can. By using a semiconductor light emitting element as the light emitting element, a light emitting device with a small size, power saving, and long life can be obtained. As a suitable example of such a semiconductor light emitting device, an InGaN-based LED or LD having good light emission characteristics in a wavelength region near 400 nm can be given.

(Light wavelength conversion layer)
The light wavelength conversion layer according to the present embodiment is composed of a plurality of layers having different types and amounts of phosphors contained therein. The first layer close to the light emitting element preferably contains at least one of a red phosphor and a green phosphor. The second layer provided on the opposite side to the light emitting element with the first layer interposed therebetween preferably includes at least one of a yellow phosphor and a blue phosphor.

  Since the first layer and the second layer as a whole include at least four phosphors having different excitation light colors (for example, a red phosphor, a green phosphor, a yellow phosphor, and a blue phosphor), color rendering is performed. A highly efficient new light emitting module can be realized. In addition, since the red phosphor or the green phosphor having an excitation spectrum up to a relatively long wavelength side is included in the first layer close to the light emitting element, the first phosphor located farther from the light emitting element than the first layer. The yellow light or blue light excited by the second layer is suppressed from being reabsorbed by the first layer, and color misregistration and a decrease in luminous flux are reduced.

(First layer)
The first layer (i) contains mainly red phosphor and green phosphor, (ii) contains mainly red phosphor, (iii) contains mainly green phosphor, (iv) mainly red phosphor , Including green phosphor and yellow phosphor, (v) mainly including red phosphor, green phosphor and blue phosphor, (vi) mainly including red phosphor and yellow phosphor, (vii) mainly In the case of including a green phosphor and a yellow phosphor, Each phosphor is dispersed in a sealing resin such as silicone or a matrix phase of glass. In the light wavelength conversion layer according to the present embodiment, there may be a case where a phosphor having the same color as the phosphor included in the first layer is included in the second layer. For example, among phosphors of a certain color included in the entire light wavelength conversion layer, the first layer may contain 90% or more and the second layer may contain 10% or less. Alternatively, 95% or more may be contained in the first layer and 5% or less may be contained in the second layer. Alternatively, the first layer may contain 98% or more and the second layer may contain 2% or less.

  The density | concentration of the whole fluorescent substance contained in a 1st layer should just be 0.2 vol% or more, Preferably it is 0.5 vol% or more, More preferably, it is 0.8 vol% or more. When the concentration of the entire phosphor is 0.2 vol% or more, visible light with a sufficient luminous flux can be generated by the light emitted from the light emitting element. Moreover, the density | concentration of the whole fluorescent substance contained in a 1st layer should just be 1.5 vol% or less, Preferably it is 1.3 vol% or less, More preferably, it is 1.1 vol% or less. If the concentration of the entire phosphor is 1.5 vol% or less, the proportion of visible light that is excited by the phosphor is scattered and shielded by other phosphors is reduced, and the decrease in the luminous efficiency of the light emitting module is suppressed. .

(Second layer)
When the second layer includes (i) mainly a blue phosphor and a yellow phosphor, (ii) mainly includes a blue phosphor, a yellow phosphor and a green phosphor, (iii) mainly a blue phosphor and a yellow phosphor And (iv) a case where mainly a blue phosphor is included, and (v) a case where a yellow phosphor is mainly included. Each phosphor is dispersed in a sealing resin such as silicone or a matrix phase of glass. In the light wavelength conversion layer according to the present embodiment, there may be a case where a phosphor having the same color as the phosphor included in the second layer is included in the first layer. For example, among phosphors of a certain color contained in the entire light wavelength conversion layer, the second layer may contain 90% or more and the first layer may contain 10% or less. Alternatively, 95% or more may be contained in the second layer, and 5% or less may be contained in the first layer. Or you may make it contain 98% or more in a 2nd layer, and 2% or less in a 1st layer.

  The density | concentration of the whole fluorescent substance contained in a 2nd layer should just be 0.6 vol% or more, Preferably it is 0.8 vol% or more, More preferably, it is 0.9 vol% or more. When the concentration of the entire phosphor is 0.6 vol% or more, visible light with a sufficient luminous flux can be generated by the light emitted from the light emitting element. On the other hand, if the concentration of the whole phosphor is less than 0.6 vol%, the second layer (phosphor layer) becomes large (thick) in order to ensure sufficient conversion performance, and a large amount as a matrix phase Since materials are required, the cost is high. Moreover, the density | concentration of the whole fluorescent substance contained in a 2nd layer should just be 2.0 vol% or less, Preferably it is 1.5 vol% or less, More preferably, it is 1.2 vol% or less. If the concentration of the whole phosphor is 2.0 vol% or less, the ratio of the visible light excited by the phosphor being scattered and shielded by other phosphors is reduced, and the decrease in the luminous efficiency of the light emitting module is suppressed. .

(First resin layer)
The first resin layer is a matrix phase in which various phosphors contained in the first layer are dispersed. Specifically, as the first resin layer, a silicone resin having a storage elastic modulus of 10 ⁴ to 10 ⁵ Pa at least at any temperature included in the range of −40 to 100 ° C. is preferable. Moreover, the 1st resin layer may be provided so that a conducting wire (bonding wire) may be sealed. Thereby, the stress acting on the conductor can be relaxed.

(Second resin layer)
The second resin layer is a matrix phase in which various phosphors contained in the second layer are dispersed. Specifically, the second resin layer is preferably a silicone resin having a Shore A hardness of 30 to 80. Thereby, the light emitting element is protected in the light emitting module covered with the second resin layer.

(Red phosphor)
The red phosphor emits light having an emission spectrum peak wavelength in the range of 620 nm to 750 nm.
(I) (Ca _1−x Sr _x ) AlSiN ₃ : Eu ²⁺ (0 ≦ x <0.4)
(Ii) Sr ₂ Si ₅ N ₈ : Eu ²⁺
(Iii) (Ca, Sr, Ba) ₃ SiO ₅ : Eu ²⁺
The substance represented by the composition formula of

(Green phosphor)
The green phosphor emits light having an emission spectrum peak wavelength in the range of 495 nm to 570 nm.
(I) (Ba, Sr, Ca) ₂ SiO ₄ : Eu ²⁺
(Ii) (Ba, Sr) ₂ SiO ₄ : Eu ²⁺
(Iii) Sr ₂ SiO ₄ : Eu ²⁺
(Iv) Eu-activated β sialon (v) Ba ₃ Si ₆ O ₁₂ N ₂ : Eu ²⁺
(Vi) SrGa ₂ S ₄ : Eu ²⁺
(Vii) SrSi ₂ O ₂ N ₂ : Eu ²⁺
(Viii) (Ba, Sr) Si ₂ O ₂ N ₂ : Eu ²⁺
(Ix) SrAlO ₄ : Eu ²⁺
(X) (Sr, Ba) Al ₂ Si ₂ O ₈ : Eu ²⁺
(Xi) (Ba, Sr, Ca) ₂ (Mg, Zn) Si ₂ O ₇ : Eu ²⁺
_{(Xii) Sr 2 Si 3 O} 8 -2SrCl 2: Eu 2+
The substance represented by the composition formula of

(Yellow phosphor)
The yellow phosphor emits light having an emission spectrum peak wavelength in the range of 570 nm to 590 nm. For example, the general formula is (M ² _x , M ³ _y , M ⁴ _z ) _m M ¹ O ₃ X _{( 2 / n)}
(Here, M ¹ is at least one element including Si selected from the group consisting of Si, Ge, Ti, Zr and Sn, and M ² is at least Ca selected from the group consisting of Ca, Mg, Ba and Zn. M ³ is one or more elements containing at least Sr selected from the group consisting of Sr, Mg, Ba and Zn, X is at least one halogen element, M ⁴ is a rare earth element and Mn 1 or more elements including at least Eu ²⁺ selected from the group consisting of: m is in the range of 0.11 ≦ m ≦ 8/6, n is in the range of 5 ≦ n ≦ 7, and x and y , Z is a range satisfying x + y + z = 1, 0 <x <1, 0 <y <1, 0.01 ≦ z ≦ 0.3).

(Blue phosphor)
The blue phosphor emits light having an emission spectrum peak wavelength in the range of 435 nm to 495 nm, for example,
(I) BaMgAl ₁₀ O ₁₇ : Eu ²⁺
(Ii) (Sr, Ca, Ba) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu ²⁺
(Iii) Ba ₃ MgSi ₂ O ₈ : Eu ²⁺
(Iv) Sr ₃ MgSi ₂ O ₈ : Eu _{2+
(V) SiO 2 -CaI 2:} Eu 2+
(Vi) Sr ₄ Al ₁₄ O ₂₄ : Eu ²⁺
(Vii) (Ba, Sr, Ca) ₂ (B ₅ O ₉ ) X ₂ : Eu ²⁺ (X is a halogen element)
(Viii) (Sr, Ba) ₃ MgSi ₂ O ₈ : Eu ²⁺
(Ix) Ca _5-xy Mg _x (PO ₄ ) ₃ Cl: Eu ²⁺ _y
(X) Sr _5-y (PO ₄ ) ₃ Cl: Eu ²⁺ _y
(Xi) Ca _5-xy Sr _x (PO ₄ ) ₃ Cl: Eu ²⁺ _y
The substance represented by the composition formula of

(Other phosphors)
In addition to the above-described phosphors, or in place of some phosphors, an orange phosphor or another color phosphor may be used. The orange phosphor emits light having an emission spectrum peak wavelength in the range of 590 nm to 620 nm.

(Light emitting module manufacturing method)
Next, an example of a method for manufacturing the light emitting module according to the present embodiment will be described. First, one or a plurality of LED chips that emit near-ultraviolet rays or short-wavelength visible light are mounted on a substrate made of alumina, aluminum, glass-reinforced epoxy resin, or the like on which a circuit pattern is formed in advance. The mounting method is performed by, for example, a method in which an LED chip is packaged in advance and then solder-mounted, or a chip-on-board mounting in which an LED chip is bonded to a substrate with a die bonding material and then bonded to a gold wire.

  Immediately above each mounted LED chip, a phosphor that absorbs light emitted from the LED chip and converts it into green light, or a silicone resin that similarly contains a phosphor that converts into red light is mounted.

The mounting of the silicone resin as the first layer is (1) pre-molding the phosphor-containing silicone resin into a sheet and bonding the silicone resin to the substrate, or (2) applying the phosphor-containing silicone to the LED chip. It is carried out by curing after applying a constant amount of drop on the top. In this case, the resin (adhesion of (1), dripping of (2)) in contact with the LED chip has a storage elastic modulus of 10 ⁴ to 10 ⁵ Pa at at least one temperature included in the range of −40 to 100 ° C. A low modulus resin is preferred.

Next, a silicone resin (second layer) in which a blue phosphor or a yellow phosphor is dispersed is mounted. In particular,
(1) On the substrate on which the first layer described above is mounted, a silicone resin in which blue phosphor or yellow phosphor is dispersed is applied so as to have an appropriate thickness in the range of 3 to 15 mm. Heat cure.
(2) The mold is filled with a silicone resin in which a blue phosphor or a yellow phosphor is dispersed, a substrate on which the first layer is mounted is placed in the opening of the mold, and is cured by heating.
(3) Fill a mold with a silicone resin in which a blue phosphor or a yellow phosphor is dispersed, and heat cure. And the hardened | cured molded product is bonded together to the board | substrate which mounted the above-mentioned 1st layer using transparent resin.

[Example 1]
1 is a cross-sectional view schematically showing an outline of a light emitting module according to Example 1. FIG. A light emitting module 10 shown in FIG. 1 includes a ceramic substrate 12, an nUV-LED chip 14 mounted on the substrate 12 via a resin, a circuit pattern formed on the substrate 12, and an electrode of the nUV-LED chip 14. And a wire 16 made of pure gold and an optical wavelength conversion layer 18. The nUV-LED chip 14 is an LED chip that emits short-wavelength visible light having a peak in the vicinity of 405 nm.

  The light wavelength conversion layer 18 includes a first layer 20 and a second layer 22 provided on the opposite side of the nUV-LED chip 14 with the first layer 20 interposed therebetween. In the first layer 20, the red phosphor 24 and the green phosphor 26 are dispersed in the first resin layer 21. The second layer 22 is obtained by dispersing the yellow phosphor 30 and the blue phosphor 32 in the second resin layer 28.

In Example 1, the red phosphor 24 ((Ca, Sr) SiAlN ₃ is added to the relatively soft silicone resin (I) having a storage elastic modulus of 0.4 MPa so that the concentration of the entire phosphor becomes 1.0 vol%. : Eu ²⁺ ) and green phosphor 26 ((Ba, Sr) ₂ SiO ₄ : Eu ²⁺ ) were mixed at a weight ratio of 3: 1 and dispersed / vacuum defoamed to prepare a silicone resin (I) coating solution. The mixing ratio of the red phosphor 24 and the green phosphor 26 may be set as appropriate in the range of red phosphor: green phosphor = 65: 35 to 85:15 (weight ratio).

  Next, a silicone resin (I) coating solution in which the amount of the phosphor contained is adjusted is applied using a dispenser so that the nUV-LED chip 14 and the wire 16 on the substrate 12 are sealed. Thereby, the wire 16 is protected. The application amount is 0.010 to 0.015 g / chip. Then, it heat-hardens at 150 degreeC and 1 h, and the 1st layer 20 is formed.

Next, the blue phosphor 32 ((Ca, Sr) ₅ (PO) is added to a relatively hard silicone resin (II) having a storage elastic modulus of 5.5 MPa so that the concentration of the entire phosphor becomes 1.0 vol%. ₄ ) ₃ Cl: Eu ²⁺ ), yellow phosphor 30 ((Ca, Sr) ₇ (SiO ₃ ) ₆ Cl ₂ : Eu ²⁺ ) are mixed at a weight ratio of 3: 2, dispersed / vacuum defoamed to obtain a silicone resin (II) was prepared. Note that the mixing ratio of the blue phosphor 32 and the yellow phosphor 30 may be appropriately set in the range of blue phosphor: yellow phosphor = 50: 50 to 70:30 (weight ratio).

  Next, a silicone resin (II) in which the amount of the phosphor contained is adjusted is filled into a mold having a hemispherical cavity of φ10 mm. At this time, vacuum filling may be performed so as not to entrain air. And the board | substrate 12 is installed so that the cavity opening surface of the type | mold filled with silicone resin (II) may be block | closed, and it is made to carry out hardening joining by 150 degreeC and 1 hour heat processing.

  FIG. 2 is a diagram illustrating an example of an excitation spectrum and an emission spectrum of a red phosphor used in the examples. FIG. 3 is a diagram illustrating an example of an excitation spectrum and an emission spectrum of the green phosphor used in the examples. FIG. 4 is a diagram illustrating an example of an excitation spectrum and an emission spectrum of a yellow phosphor used in the examples. FIG. 5 is a diagram illustrating an example of an excitation spectrum and an emission spectrum of a blue phosphor used in the examples.

  As shown in FIG. 2, the peak wavelength λp of the emission spectrum L1 of the red phosphor according to Example 1 is in the range of 625 nm to 635 nm. The excitation end wavelength λe of the excitation spectrum L2 is in the range of 530 nm to 540 nm. Here, the excitation end wavelength λe indicates a wavelength at which the decrease in excitation intensity on the long wavelength side in the excitation spectrum L2 starts to decrease rapidly. The half-value wavelength λh of the excitation spectrum L2 is in the range of 560 nm to 570 nm. Here, the half-value wavelength λh indicates a wavelength at which the intensity Ih is 50% of the peak intensity Imax on the long wavelength side of the excitation spectrum L2.

  As shown in FIG. 3, the peak wavelength λp of the emission spectrum L3 of the green phosphor according to Example 1 is in the range of 520 nm to 530 nm. The excitation end wavelength λe of the excitation spectrum L4 is in the range of 450 nm to 460 nm. The half-value wavelength λh of the excitation spectrum L4 is in the range of 470 nm to 480 nm.

  As shown in FIG. 4, the peak wavelength λp of the emission spectrum L5 of the yellow phosphor according to Example 1 is in the range of 570 nm to 580 nm. The excitation end wavelength λe of the excitation spectrum L6 is in the range of 410 nm to 420 nm. The half-value wavelength λh of the excitation spectrum L6 is in the range of 435 nm to 445 nm.

  As shown in FIG. 5, the peak wavelength λp of the emission spectrum L7 of the blue phosphor according to Example 1 is in the range of 455 nm to 465 nm. The excitation end wavelength λe of the excitation spectrum L8 is in the range of 390 nm to 400 nm. Further, the half-value wavelength λh of the excitation spectrum L8 is in the range of 400 nm to 410 nm.

[Example 2]
FIG. 6 is a side view schematically showing an outline of the light emitting module according to the second embodiment. FIG. 7 is a cross-sectional view of the light emitting module shown in FIG.

  The light emitting module 110 shown in FIG. 6 includes a ceramic substrate 112, a plurality of nUV-LED chips 14 mounted on the substrate 112 via a resin, a circuit pattern formed on the substrate 112, and the nUV-LED chip 14. A wire 16 made of pure gold and an optical wavelength conversion layer 118 are provided.

  The light wavelength conversion layer 118 includes a first layer 120, a second layer 122 provided on the opposite side of the nUV-LED chip 14 across the first layer 120, a first layer 120, a second layer And a transparent layer 124 that joins the layer 122. The first layer 120 is obtained by dispersing the red phosphor 24 and the green phosphor 126 in the first resin layer 21. The second layer 122 is obtained by dispersing the yellow phosphor 30 and the blue phosphor 32 in the second resin layer 28. The transparent layer 124 may contain a phosphor used for the first layer 120 and the second layer 122.

In Example 2, the red phosphor 24 ((Ca, Sr) SiAlN ₃ was added to the relatively soft silicone resin (I) having a storage elastic modulus of 0.4 MPa so that the concentration of the entire phosphor was 1.0 vol%. : Eu ²⁺ ) and green phosphor 126 (β-sialon) were mixed at a weight ratio of 4: 1 and dispersed / vacuum defoamed to prepare a silicone resin (I) coating solution. The mixing ratio of the red phosphor 24 and the green phosphor 126 may be set as appropriate in the range of red phosphor: green phosphor = 65: 35 to 85:15 (weight ratio).

  The substrate 112 according to the second embodiment is a ceramic substrate having a length of 200 mm, and 24 nUV-LED chips 14 are mounted on the mounting surface at a pitch of 8 mm. Next, using a dispenser, a silicone resin (I) coating solution in which the amount of the phosphor contained is adjusted is applied so that the nUV-LED chip 14 and the wire 16 on the substrate 112 are sealed, The first layer 20 having a height of 1 mm, a width of 3 mm, and a length of less than 200 mm is formed by heat curing at 150 ° C. for 1 hour. Thereby, the wire 16 is protected.

Next, the blue phosphor 32 ((Ca, Sr) ₅ (PO) is added to a relatively hard silicone resin (II) having a storage elastic modulus of 5.5 MPa so that the concentration of the entire phosphor becomes 1.0 vol%. ₄ ) ₃ Cl: Eu ²⁺ ), yellow phosphor 30 ((Ca, Sr) ₇ (SiO ₃ ) ₆ Cl ₂ : Eu ²⁺ ) are mixed at a weight ratio of 1: 1, and dispersed / vacuum defoamed to obtain a silicone resin. (II) was prepared. Note that the mixing ratio of the blue phosphor 32 and the yellow phosphor 30 may be appropriately set in the range of blue phosphor: yellow phosphor = 50: 50 to 90:10 (weight ratio).

  Next, the silicone resin (II) in which the amount of the contained phosphor is adjusted is formed into a mold having a substantially triangular prism-shaped cavity (see FIG. 7) having a width of 10 mm, a depth of 8 mm, and a length of 200 mm. Fill. At this time, vacuum filling may be performed so as not to entrain air.

  Next, the above-described cavity mold filled with the silicone resin (II) is used as a lower mold, and an upper mold that closes the cavity is prepared. The upper mold has a convex shape with a width of 4 to 8 mm and a height of 1 to 3 mm at the center. After these lower and upper molds are clamped, they are placed in a heating furnace and heat treated at 150 ° C. for 1 h to cure the silicone resin, and then demolded to obtain a phosphor-containing silicone molded body.

  Accordingly, the silicone molded body has a groove having a width of 4 to 8 mm and a depth of 1 to 3 mm formed on the lower surface. The groove is filled with an adhesive transparent resin (for example, dimethyl silicone resin is suitable) to be the transparent layer 124, and the substrate 112 on which the first layer 20 is formed is laminated on the transparent layer 124. The transparent resin is cured by heat treatment at 150 ° C. for 1 hour, and the light emitting module 110 is manufactured.

[Comparative Example 1]
Blue phosphor 32 ((Ca, Sr) ₅ (PO ₄ ) ₃ is added to a relatively hard silicone resin (II) having a storage elastic modulus of 5.5 MPa so that the concentration of the entire phosphor becomes 1.0 vol%. Cl: Eu ²⁺ ) and yellow phosphor 30 ((Ca, Sr) ₇ (SiO ₃ ) ₆ Cl ₂ : Eu ²⁺ ) are mixed at a weight ratio of 1: 1 and dispersed / vacuum defoamed to obtain a silicone resin (II). It was created.

  Next, a silicone resin (II) in which the amount of the phosphor contained is adjusted is filled into a mold having a hemispherical cavity of φ10 mm. At this time, vacuum filling may be performed so as not to entrain air. And the board | substrate 12 is installed so that the cavity opening surface of the type | mold filled with silicone resin (II) may be block | closed, and it is made to carry out hardening joining by 150 degreeC and 1 hour heat processing. In addition, the light emitting module which concerns on the comparative example 1 is substantially the same as the structure of the light emitting module 10 except not having the 1st layer 20 in the light emitting module 10 which concerns on Example 1. FIG.

(Characteristic evaluation)
In the light emitting modules in Example 1, Example 2, and Comparative Example 1 described above, the average color rendering coefficient, color temperature, and chromaticity coordinates (cx, cy) were measured. The measurement results are shown in Table 1.

  As shown in Table 1, the light emitting module 10 according to Example 1 realizes light with high color rendering properties from daylight white to daylight. Further, the light emitting module 110 according to the second embodiment realizes light having a light bulb color and high color rendering properties. On the other hand, the color rendering properties of the light emitting module according to Comparative Example 1 remain similar to those of a general residential ceiling light.

  FIG. 8 is a diagram illustrating an emission spectrum of the light emitting module according to Example 1 and an emission spectrum of the light emitting module according to Comparative Example 1. As shown in FIG. 8, the light emitting module 10 according to Example 1 has improved intensities in the green and red wavelength regions of the emission spectrum as compared with the light emitting module according to Comparative Example 1.

  FIG. 9 is a diagram showing an emission spectrum of the light emitting module according to Example 2. As shown in FIG. 9, in the light emitting module 110 according to Example 2, the intensity of the emission spectrum in the green and red wavelength ranges is larger than the intensity in the yellow and blue wavelength ranges, and the color rendering is high and warm. It turns out that light emission of a certain light bulb color is realized.

  As described above, in the light emitting modules according to Example 1 and Example 2, the red phosphor and the green phosphor in which the excitation spectrum exists up to a relatively long wavelength side are included in the first layer 20 close to the nUV-LED chip. Therefore, yellow light and blue light excited by the second layer are suppressed from being absorbed by the first layer, and color misregistration and a decrease in light flux are reduced.

  The first layer may include a red phosphor, and the second layer may include a green phosphor, a yellow phosphor, and a blue phosphor. As a result, the red phosphor having an excitation spectrum up to a relatively long wavelength side is included in the first layer close to the light emitting element, so that yellow light or blue light excited in the second layer is the first. Re-absorption by the layer is suppressed, and a color shift and a decrease in luminous flux are reduced.

[Example 3]
The green phosphor 26 ((Ba, Sr) ₂ SiO ₄ : Eu ²⁺ ) used in Example 1 is an orthosilicate phosphor, and an oxynitride such as the green phosphor 126 used in Example 2 is used. Compared with the β-SiAlON-based phosphor, the cost is low. On the other hand, orthosilicate phosphors are ionic crystalline crystals that are easily hydrated and have low durability, and thus are strongly affected by heat and light energy. Therefore, there is a possibility that the green phosphor is deteriorated (light emission intensity is lowered) even at room temperature lighting. In particular, as in the case of the green phosphor 26 shown in the first embodiment, when it is arranged on the first layer 20 in the immediate vicinity of the nUV-LED chip 14, it is more strongly affected by heat and light energy.

  Therefore, the green phosphor 26 according to Example 3 is not contained in the first layer close to the nUV-LED chip 14 but in the second layer separated from the first layer. In addition to the orthosilicate green phosphor, it is clear that the configuration shown in Example 3 is effective from the viewpoint of preventing deterioration if it is a green phosphor that is easily affected by heat and light energy.

  FIG. 10 is a cross-sectional view schematically showing an outline of the light emitting module according to Example 3. As shown in FIG. A light emitting module 210 shown in FIG. 10 includes a ceramic substrate 112, a plurality of nUV-LED chips 114 mounted on the substrate 112 via a resin, a circuit pattern formed on the substrate 112, and the nUV-LED chip 14. A wire made of pure gold (not shown) for connecting the electrode and the light wavelength conversion layer 218.

  The light wavelength conversion layer 218 includes a first layer 220 and a second layer 222 provided on the opposite side of the nUV-LED chip 14 with the first layer 220 interposed therebetween. In the first layer 220, the red phosphor 24 and the first yellow phosphor 30 a are dispersed in the first resin layer 221. The second layer 222 is obtained by dispersing the green phosphor 26, the second yellow phosphor 30 b, and the blue phosphor 32 in the second resin layer 228.

  Here, the first yellow phosphor 30a and the second yellow phosphor 30b may be the same type of phosphor, or may be phosphors of different types. Here, the different types of phosphors include not only the case where the types of elements included in the phosphors are different, but also the case where the composition ratios of the elements included are the same, but different.

In Example 3, the red phosphor 24 (Ca _1-x AlSiN ₃ : Eu ²⁺⁾ is formed on the first resin layer 221 such as a silicone resin so that the concentration of the entire phosphor becomes 0.2 to 1.5 vol%. _x ) and the first yellow phosphor 30a ((Ca, Sr) ₇ (SiO ₃ ) ₆ Cl ₂ : Eu ²⁺ ) are mixed at a weight ratio of 80:20.

  Then, using a dispenser, a silicone resin coating solution in which the phosphor is mixed is applied so that the nUV-LED chip 14 and the like on the substrate 112 are sealed, and is heated and cured at 150 ° C. for 1 hour. Layer 220 is formed.

Next, an addition polymerization type silicone resin (MS-1002 (A / B) manufactured by Toray Dow Corning Co., Ltd.) is used so that the concentration of the entire phosphor becomes 0.5 to 5 vol%. , Sr) ₅ (PO ₄ ) ₃ Cl: Eu ²⁺ ), second yellow phosphor 30 b ((Ca, Sr) ₇ (SiO ₃ ) ₆ Cl ₂ : Eu ²⁺ ), green phosphor 26 ((Ba, Sr) ) ₂ SiO ₄ : Eu) was mixed in a weight ratio of 60:30:10. In that case, it mixes carefully with a self-revolving stirring de-mixing apparatus.

  Thereafter, the mixture is poured into an aluminum cutting die to form the second layer 222, and the substrate 112 on which the nUV-LED chip 14 is sealed with the first layer 220 is placed on the second layer, and the whole is placed. Was cured by heating to produce a white light emitting module 210.

  Using this light emitting module 210, a room temperature lighting test (If = 160 mA) was performed, and the emission spectra after the initial time and after 200 hours were compared. FIG. 11 is a diagram illustrating a change in the emission spectrum of the light emitting module according to Example 3. As shown in FIG. 11, the light emission module 210 has almost no change in the emission spectrum even when the lighting time is increased. In this evaluation, the light emitting module 210 was energized at 100 mA, and the emission characteristics of the emitted light were evaluated with a spectrum measuring apparatus (CAS140B) manufactured by Instrument System.

  As described above, the present invention has been described with reference to the above-described embodiment and examples. However, the present invention is not limited to the above-described embodiment, and the configuration of the embodiment is appropriately combined or replaced. Those are also included in the present invention. In addition, it is possible to appropriately change the combination and processing order in the embodiment based on the knowledge of those skilled in the art and to add various modifications such as various design changes to the embodiment. The described embodiments can also be included in the scope of the present invention.

  DESCRIPTION OF SYMBOLS 10 Light emitting module, 12 board | substrate, 14 nUV-LED chip, 16 wires, 18 light wavelength conversion layer, 20 1st layer, 21 1st resin layer, 22 2nd layer, 24 red fluorescent substance, 26 green fluorescent substance 28 second resin layer, 30 yellow phosphor, 32 blue phosphor, 110 light emitting module, 112 substrate, 118 light wavelength conversion layer, 120 first layer, 122 second layer, 124 transparent layer, 126 green phosphor body.

Claims (6)

A light emitting element emitting ultraviolet light or short wavelength visible light;
A light wavelength conversion layer that emits visible light that is excited by light emitted from the light emitting element, and
The light wavelength conversion layer is
A first layer, and a second layer provided on the opposite side of the light emitting element across the first layer,
The first layer and the second layer include a red phosphor, a green phosphor, a yellow phosphor and a blue phosphor,
The first layer includes at least one of the red phosphor and the green phosphor,
The second layer includes at least one of the yellow phosphor and the blue phosphor.
A light emitting module characterized by that. The first layer includes the red phosphor and the green phosphor,
The second layer includes the yellow phosphor and the blue phosphor.
The light-emitting module according to claim 1. The first layer includes the red phosphor,
The second layer includes the green phosphor, the yellow phosphor, and the blue phosphor.
The light-emitting module according to claim 1. The yellow phosphor includes a first yellow phosphor and a second yellow phosphor,
The first layer includes the red phosphor and the first yellow phosphor as the yellow phosphor,
The second layer includes the green phosphor, the blue phosphor, and the second yellow phosphor as the yellow phosphor.
The light-emitting module according to claim 1. A substrate on which the light emitting element is mounted;
A conductive wire that electrically connects the light emitting element and the substrate;
The first layer is a first resin layer in which the red phosphor and the green phosphor are dispersed and having an elastic modulus of 104 to 105 Pa at least in a temperature range of −40 to 100 ° C. Have
The light emitting module according to claim 1, wherein the first resin layer is provided so as to seal the conducting wire.   6. The second layer according to claim 1, wherein the second layer has a second resin layer having a Shore A hardness of 30 to 80 in which a yellow phosphor and a blue phosphor are dispersed. The light emitting module as described.