JP2015109391A - Light emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light emitting device which can improve color rendering property and achieve a high output of an optical output.SOLUTION: A light emitting device 1a comprises a mounting substrate 2, a light emitting element 3, a first wavelength conversion layer 4 which covers the light emitting element 3, and a second wavelength conversion layer 5 arranged away from the first wavelength conversion layer 4. The first wavelength conversion layer 4 is formed by a mixture of a first translucent material and a first wavelength conversion material which converts a wavelength of a pat of light emitted from the light emitting element 3 and emits light having a different wavelength. The second wavelength conversion layer 5 is formed by a mixture of a second translucent material and a second wavelength conversion material which converts a wavelength of a part of light emitted from the light emitting element 3 and emits light having a different wavelength. The second translucent material has heat resistance higher than that of the first translucent material. The second wavelength conversion material has heat resistance higher than that of the first wavelength conversion material. The light emitting device 1a comprises a heat insulation part 6 for inhibiting heat transfer between the light emitting element 3 and the second wavelength conversion layer 5 via the mounting substrate 2.

Description

  The present invention relates to a light emitting device including light emitting elements such as an LED chip (light emitting diode chip) and an LD chip (laser diode chip).

  Conventionally, as this type of light emitting device, for example, a light emitting device 130 configured as shown in FIG. 9 has been proposed (Patent Document 1).

  The light emitting device 130 includes an LED chip 104 as a light emitting element, a substrate 102 to which the LED chip 104 is fixed, and a sealing outer layer 108 having translucency. The light emitting device 130 includes a die bond agent 105 that fixes the LED chip 104 to the substrate 102. The light emitting device 130 includes a light emitting element surface layer 121 that is in close contact with the surface of the LED chip 104 and covers the LED chip 104.

  The sealing outer layer 108 is formed of a strong translucent resin or the like. The inside of the sealing outer layer 108 is hollow.

  The LED chip 104 emits ultraviolet light or near ultraviolet light. The sealing outer layer 108 contains a blue phosphor 110B. The light emitting element surface layer 121 contains a green phosphor 110G. The die bond agent 105 contains a red phosphor 110R.

  Moreover, as an illuminating device, the illuminating device 301 of the structure shown in FIG. 10, for example is proposed (patent document 2).

  The lighting device 301 includes at least one red LED 302, at least one blue LED 303, a support substrate 309, a side wall portion 310, a light exit window 307, a wavelength conversion material 305, and a reflective coating 311. .

  The wavelength converting material 305 can be re-emitted as green or greenish light at least a portion of the light emitted by the blue LED 303.

JP 2009-267039 A Special table 2012-507827 gazette

  In the field of light-emitting devices, not only the light-emitting device 130 and the lighting device 301 but also a further improvement in light output is desired.

  However, in the light emitting device 130, the junction temperature of the LED chip 104 is likely to increase due to the effects of heat generated in the green phosphor 110G of the light emitting element surface layer 121 and heat generated in the red phosphor 110R of the die bond agent 105. Become. For this reason, in the light emitting device 130, it is difficult to increase the optical output by increasing the input current.

  Further, in the light emitting device 130, the red phosphor 110R is easily affected by the heat of the LED chip 104, and the efficiency is lowered by the temperature quenching of the red phosphor 110R.

  Further, in the lighting device 301, the heat generated in the wavelength conversion material 305 is not easily dissipated to the support substrate 309, and the temperature of the wavelength conversion material 305 tends to increase. For this reason, in the illuminating device 301, if a phosphor having a large temperature quenching (for example, a red phosphor) is used as the wavelength conversion material 305, the efficiency is lowered. It is difficult.

  The present invention has been made in view of the above-described reasons, and an object of the present invention is to provide a light-emitting device capable of improving the color rendering properties and increasing the light output. .

  The light emitting device of the present invention includes a mounting substrate, a light emitting element mounted on the first surface side of the mounting substrate, a first wavelength conversion layer covering the light emitting element, and the light emission in the first wavelength conversion layer. And a second wavelength conversion layer disposed away from the first wavelength conversion layer on the side opposite to the element side. The first wavelength conversion layer is a mixture of a first light-transmitting material and a first wavelength conversion material that converts a part of the light emitted from the light emitting element to emit light of a different wavelength. Is formed. The second wavelength conversion layer is a mixture of a second translucent material and a second wavelength conversion material that converts a part of light emitted from the light emitting element to emit light of different wavelengths. Is formed. The second light transmissive material has higher heat resistance than the first light transmissive material. The second wavelength conversion material has higher heat resistance than the first wavelength conversion material. The light-emitting device of this invention is equipped with the heat insulation part which suppresses the heat transfer via the said mounting board | substrate between the said light emitting element and the said 2nd wavelength conversion layer.

  In this light emitting device, it is preferable that the first light transmissive material is a light transmissive resin and the second light transmissive material is glass.

  In this light-emitting device, it is preferable that the first wavelength conversion material is a red phosphor, and the second wavelength conversion material is a yellow phosphor.

  In the light emitting device, the second wavelength conversion layer is preferably formed in a plate shape.

  In this light emitting device, a plurality of the light emitting elements are provided on the first surface side of the mounting substrate, and only a part of the light emitting elements among the plurality of light emitting elements is covered with the first wavelength conversion layer. Is preferred.

  In this light emitting device, it is preferable that the second wavelength conversion layer is located on the inner side of the outer peripheral line of the projection region in the thickness direction of the light emitting element.

  In this light-emitting device, the second wavelength conversion layer is located on the inner side of the outermost line of the projection region in the thickness direction of the mounting substrate of the smallest convex polygon that includes all of the plurality of light-emitting elements. It is preferable.

  In the light emitting device of the present invention, the color rendering properties can be improved by providing the first wavelength conversion layer and the second wavelength conversion layer. Further, in the light emitting device of the present invention, the second light transmissive material having higher heat resistance than the first light transmissive material, and the second wavelength conversion material having higher heat resistance than the first wavelength conversion material. And the second wavelength conversion layer formed of a mixture is disposed away from the first wavelength conversion layer covering the light emitting element, and further includes the heat insulating portion. Therefore, in the light emitting device of the present invention, it is possible to reduce the amount of heat generated in the vicinity of the light emitting element and supply a larger current to the light emitting element. Is possible.

FIG. 1A is a schematic plan view showing the light emitting device of the first embodiment. FIG.1 (b) is BB schematic sectional drawing of Fig.1 (a). FIG. 2A is a schematic plan view showing a first modification of the light emitting device of the first embodiment. FIG.2 (b) is BB schematic sectional drawing of Fig.2 (a). FIG. 3 is a schematic cross-sectional view illustrating a second modification of the light-emitting device of Embodiment 1. FIG. 4 is a schematic cross-sectional view illustrating a third modification of the light-emitting device of Embodiment 1. FIG. 5 is a schematic cross-sectional view illustrating a fourth modification of the light emitting device of the first embodiment. FIG. 6A is a schematic plan view showing the light emitting device of the second embodiment. FIG. 6B is a schematic cross-sectional view taken along the line BB in FIG. FIG. 7 is a schematic cross-sectional view showing a first modification of the light emitting device of the second embodiment. FIG. 8 is a schematic cross-sectional view showing a second modification of the light emitting device of the second embodiment. FIG. 9 is a schematic cross-sectional view showing a conventional light emitting device. FIG. 10 is a schematic cross-sectional view of a conventional illumination device.

(Embodiment 1)
Below, the light-emitting device 1a of this embodiment is demonstrated based on Fig.1 (a) and (b).

  The light emitting device 1 a includes a mounting substrate 2, a light emitting element 3 mounted on the first surface 2 a side of the mounting substrate 2, a first wavelength conversion layer 4 covering the light emitting element 3, and a first wavelength conversion layer 4. And a second wavelength conversion layer 5 disposed away from the first wavelength conversion layer 4 on the side opposite to the light emitting element 3 side. The first wavelength conversion layer 4 is a mixture of a first translucent material and a first wavelength conversion material that converts a part of the light emitted from the light emitting element 3 to emit light of different wavelengths. Is formed. The second wavelength conversion layer 5 is a mixture of a second translucent material and a second wavelength conversion material that radiates light of different wavelengths by converting part of the light emitted from the light emitting element 3. Is formed. The second light transmissive material has higher heat resistance than the first light transmissive material. The second wavelength conversion material has higher heat resistance than the first wavelength conversion material. In addition, the light emitting device 1 a includes a heat insulating portion 6 that suppresses heat transfer through the mounting substrate 2 between the light emitting element 3 and the second wavelength conversion layer 5. Therefore, the light emitting device 1a can increase the light output of the light emitting element 3.

  Each component of the light emitting device 1a will be described in more detail below.

  The light emitting element 3 is constituted by an LED chip 30. The LED chip 30 includes a substrate 31 and includes a multilayer film 32 formed of a semiconductor material on the first surface 31 a side of the substrate 31. The multilayer film 32 includes a first conductivity type semiconductor layer and a second conductivity type semiconductor layer. The multilayer film 32 is formed such that the first conductivity type semiconductor layer is closer to the first surface 31a of the substrate 31 than the second conductivity type semiconductor layer. In other words, the second conductivity type semiconductor layer is formed on the opposite side of the first conductivity type semiconductor layer from the substrate 31 side. In the LED chip 30, the first conductivity type semiconductor layer is composed of an n-type semiconductor layer, and the second conductivity type semiconductor layer is composed of a p-type semiconductor layer. In the LED chip 30, the first conductivity type semiconductor layer may be constituted by a p-type semiconductor layer, and the second conductivity type semiconductor layer may be constituted by an n-type semiconductor layer.

  The substrate 31 has a function of supporting the multilayer film 32. The multilayer film 32 can be formed by an epitaxial growth method or the like. As the epitaxial growth method, a crystal growth method can be adopted. Examples of the crystal growth method include metal organic vapor phase epitaxy (MOVPE) method, hydride vapor phase epitaxy (HVPE) method, molecular beam epitaxy (MBE) method, and the like. Can be adopted. The multilayer film 32 may contain impurities such as hydrogen, carbon, oxygen, silicon, and iron that are inevitably mixed when the multilayer film 32 is formed. The substrate 31 can be constituted by, for example, a crystal growth substrate when the multilayer film 32 is formed.

  As the LED chip 30, for example, a blue LED chip that emits blue light can be adopted. When the LED chip 30 is composed of a GaN blue LED chip, for example, a sapphire substrate can be adopted as the substrate 31. The GaN-based blue LED chip is an LED chip that employs a GaN-based material as the semiconductor material of the multilayer film 32. Examples of the GaN-based material include GaN, AlGaN, InAlGaN, and the like. The substrate 31 only needs to be formed of a material that can efficiently transmit light emitted from the multilayer film 32, and is not limited to a sapphire substrate, and may be a GaN substrate, for example. In short, the substrate 31 is preferably a substrate that is transparent to the light emitted from the multilayer film 32. The LED chip 30 may have a configuration in which the multilayer film 32 includes a buffer layer interposed between the substrate 31 and the first conductivity type semiconductor layer. The LED chip 30 does not specifically limit the semiconductor material of the multilayer film 32. Further, the LED chip 30 does not particularly limit the emission wavelength. The LED chip 30 is not limited to a blue LED chip, and may be, for example, a purple LED chip that emits purple light.

  In the LED chip 30, the multilayer film 32 preferably includes a light emitting layer between the first conductive semiconductor layer and the second conductive semiconductor layer. In this case, the light emitted from the multilayer film 32 is light emitted from the light emitting layer, and the emission wavelength is defined by the material of the light emitting layer. The light emitting layer preferably has a single quantum well structure or a multiple quantum well structure, but is not limited thereto. For example, the LED chip 30 may form a double heterostructure with a first conductive semiconductor layer, a light emitting layer, and a second conductive semiconductor layer.

  The first conductivity type semiconductor layer is not limited to a single layer structure, and may have a multilayer structure. The second conductivity type semiconductor layer is not limited to a single layer structure, and may be a multilayer structure.

  The LED chip 30 is removed by etching a part of the multilayer film 32 from the surface side of the multilayer film 32 to the middle of the first conductivity type semiconductor layer. In short, the LED chip 30 has a mesa structure (not shown) formed by etching a part of the multilayer film 32. Thus, in the LED chip 30, a step is formed between the surface of the second conductivity type semiconductor layer and the surface of the first conductivity type semiconductor layer. In the LED chip 30, the first electrode 33 is formed on the exposed surface of the first conductivity type semiconductor layer, and the second electrode 34 is formed on the surface of the second conductivity type semiconductor layer. When the conductivity type (first conductivity type) of the first conductivity type semiconductor layer is n-type and the conductivity type (second conductivity type) of the second conductivity type semiconductor layer is p-type, the LED chip 30 is first The electrode 33 and the second electrode 34 constitute a negative electrode and a positive electrode, respectively. In the LED chip 30, when the first conductivity type is p-type and the second conductivity type is n-type, the first electrode 33 and the second electrode 34 constitute a positive electrode and a negative electrode, respectively. In any case, the LED chip 30 is provided with a first electrode 33 and a second electrode 34 on one surface side in the thickness direction of the LED chip 30.

  The chip size of the LED chip 30 is not particularly limited. When the planar shape is a rectangular shape, for example, a LED chip 30 having a chip size of 0.52 mm × 0.39 mm can be used. In addition, when the planar shape of the LED chip 30 is a square shape, for example, the chip size is 0.3 mm □ (0.3 mm × 0.3 mm), 0.45 mm □ (0.45 mm × 0.45 mm), 1 mm □. (1 mm × 1 mm) or the like can be used. The LED chip 30 is not limited to a planar shape or a chip size.

  The mounting substrate 2 is a substrate on which the light emitting element 3 is mounted. “Mounting” is a concept including arranging and mechanically connecting the light emitting elements 3 and electrically connecting them.

  The planar shape of the mounting substrate 2 is rectangular. The planar shape of the mounting substrate 2 is not limited to a rectangular shape, and may be, for example, a polygonal shape other than a rectangular shape, a circular shape, or the like.

  The mounting substrate 2 includes a support 20 and a first conductor portion 23 and a second conductor portion 24 which are formed in a predetermined pattern on the first surface 20a side of the support 20 and to which the light emitting element 3 is electrically connected. Prepare. The support 20 is formed in a flat plate shape. The mounting substrate 2 is formed so that the first conductor portion 23 and the second conductor portion 24 are spatially separated. The light emitting element 3 is flip-chip mounted on the mounting substrate 2. Thus, in the light emitting element 3, the first electrode 33 is electrically connected to the first conductor portion 23 via the first bump (not shown). In the light emitting element 3, the second electrode 34 is electrically connected to the second conductor portion 24 via a second bump (not shown). As a material of the first bump and the second bump, for example, Au is preferable.

  The support 20 can be constituted by, for example, a ceramic substrate. As a result, the light emitting device 1a can improve heat dissipation as compared with the case where the support 20 is made of a resin substrate, and the light output of the light emitting device 1a can be increased. Become.

  As a material of the ceramic substrate, for example, alumina ceramics or the like can be employed. The reflectance of the ceramic substrate can be adjusted by the type and concentration of the binder, additive, and the like. In the ceramic substrate, it is preferable that the surface constituting the first surface 20a of the support 20 has diffuse reflectivity. Thereby, the light emitting device 1a can suppress the light emitted from the light emitting element 3 to the ceramic substrate side from returning to the light emitting element 3.

  The ceramic substrate may have light diffusibility. Thereby, in the light emitting device 1a, the light emitted from the light emitting element 3 to the ceramic substrate side is diffused in the ceramic substrate. Therefore, the light emitting device 1a can further suppress the light emitted from the light emitting element 3 to the ceramic substrate side from returning to the light emitting element 3. In short, the light emitting device 1a can easily extract light from the peripheral region 202 of the projection region 201 of the light emitting element 3 on the first surface 20a of the support 20. Therefore, the light emitting device 1a can improve the light extraction efficiency, and can improve the total luminous flux. The projection region 201 of the light emitting element 3 on the first surface 20 a of the support 20 means a region where the light emitting element 3 is projected onto the first surface 20 a of the support 20 along the thickness direction of the light emitting element 3. Further, light is emitted from the peripheral region 202 on the first surface 20a of the support 20 in a portion where the first conductor portion 23 and the second conductor portion 24 are not formed.

  The light emitting device 1a may be configured such that the mounting substrate 2 includes a reflective layer that reflects light from the light emitting element 3 on the second surface 20b of the support 20 formed of a ceramic substrate. In addition, the light emitting device 1 a may be configured such that a reflective member that reflects light from the light emitting element 3 is disposed on the second surface 2 b of the mounting substrate 2. The reflective layer and the reflective member are preferably formed in a region wider than the vertical projection region of the light emitting element 3 on the second surface 20b of the support 20 formed of a ceramic substrate. In the light emitting device 1a, it is preferable that the reflective layer and the reflective member are made of metal from the viewpoint of heat dissipation. In the light emitting device 1a, it is preferable that the reflective layer and the reflective member are formed in a wider area from the viewpoint of heat dissipation. As a result, the light emitting device 1a can conduct the heat generated in the light emitting element 3 and conducted to the reflective layer and the reflective member over a wider range, and the heat dissipation can be further improved. .

  As the ceramic substrate, for example, an alumina substrate, an aluminum nitride substrate, or the like can be employed.

  The 1st conductor part 23 and the 2nd conductor part 24 can be comprised by the laminated film of Ni film | membrane and Au film | membrane, for example. The first conductor portion 23 and the second conductor portion 24 are not limited to the laminated film of the Ni film and the Au film. For example, the laminated film of the Cu film, the Ni film, the Pd film, and the Au film, the Cu film and the Ni film, A laminated film with an Au film, a laminated film with a Ti film, a Pt film, and an Au film can be employed. When the first conductor portion 23 and the second conductor portion 24 are formed of a laminated film, the uppermost layer film farthest from the support body 20 is formed of Au, and the lowermost layer film closest to the support body 20 is the support body. It is preferably formed of a material having high adhesiveness to 20. The 1st conductor part 23 and the 2nd conductor part 24 may be comprised not only with a laminated film but with a single layer film.

  The support body 20 is good also as a structure provided with the metal plate and the electrically insulating layer formed in the surface of this metal plate. As a result, the light emitting device 1a can improve heat dissipation, improve the reliability, and increase the light output of the light emitting device 1a, compared to the case where the support 20 is a resin substrate. Can be achieved. For example, an aluminum substrate, a copper substrate, or the like can be adopted as the metal plate. The mounting substrate 2 has a first conductor portion 23 and a second conductor portion 24 formed on an electrical insulating layer. The mounting substrate 2 can be formed by a metal base printed wiring board, for example.

The mounting substrate 2 can be configured to include a white resist layer. The resist layer preferably covers a portion of the electrical insulating layer where neither the first conductor portion 23 nor the second conductor portion 24 is formed. As a material for the resist layer, for example, a white resist can be employed. Examples of the white resist include a resin containing a white pigment. Examples of the white pigment include barium sulfate (BaSO ₄ ) and titanium dioxide (TiO ₂ ). Examples of the resin include a silicone resin. As the white resist, for example, “ASA COLOR (registered trademark) RESIST INK”, which is a white resist material made of silicone manufactured by Asahi Rubber Co., Ltd., can be used. The resist layer can be formed by, for example, a coating method. In the mounting substrate 2, the electrical insulating layer may be composed of a white resist layer.

  Since the light emitting device 1a includes the white resist layer, the light incident on the mounting substrate 2 from the light emitting element 3 is easily reflected on the surface of the resist layer. As a result, the light emitting device 1 a can suppress the light emitted from the light emitting element 3 from being absorbed by the mounting substrate 2. Therefore, the light emitting device 1a can improve the light output by improving the light extraction efficiency to the outside.

  In the first wavelength conversion layer 4, the first light transmissive material is preferably a light transmissive resin. As the translucent resin, for example, a silicone resin, an acrylic resin, an epoxy resin, or the like can be used.

In the first wavelength conversion layer 4, the first wavelength conversion material is preferably a red phosphor. The red phosphor is a phosphor that emits red light, which is light having a different wavelength, by converting a part of the light emitted from the light emitting element 3. As the red phosphor, for example, Eu ²⁺ activated nitride phosphor can be employed. Examples of the Eu ²⁺ activated nitride phosphor include (Sr, Ca) AlSiN ₃ : Eu ²⁺ and CaAlSiN ₃ : Eu ²⁺ . In the first wavelength conversion layer 4, the first wavelength conversion material is dispersed in the first light transmissive material.

  The first wavelength conversion layer 4 is formed so as to cover the surface of the light emitting element 3 other than the surface facing the mounting substrate 2. The first wavelength conversion layer 4 is formed in close contact with the light emitting element 3. The first wavelength conversion layer 4 can be formed, for example, so that the thickness on the surface of the light emitting element 3 is substantially the same. As a result, the light emitting device 1a can uniformize the optical path length from the light emitting element 3 to the surface 4a of the first wavelength conversion layer 4 regardless of the direction of light emission from the light emitting element 3, and color unevenness. Can be further suppressed. The first wavelength conversion layer 4 can be formed by, for example, a screen printing method or the like.

  The shape of the first wavelength conversion layer 4 is not particularly limited, and may be a hemispherical shape or a semi-elliptical spherical shape.

  As for the 2nd wavelength conversion layer 5, it is preferable that the 2nd translucent material is glass. The second light transmissive material is not limited to glass, and may be a light transmissive resin as long as it has higher heat resistance than the first light transmissive material. As the translucent resin, for example, a silicone resin, an acrylic resin, an epoxy resin, or the like can be used. The light emitting device 1a may employ a silicone resin as the first light transmissive material, and may employ a silicone resin having higher heat resistance than the first light transmissive material as the second light transmissive material.

In the second wavelength conversion layer 5, the second wavelength conversion material is preferably a yellow phosphor. The yellow phosphor is a phosphor that emits yellow light, which is light having a different wavelength, by converting a part of the light emitted from the light emitting element 3. As the yellow phosphor, for example, a Ce ³⁺ activated YAG (Yttrium Aluminum Garnet) phosphor, Eu ²⁺ activated oxynitride phosphor, or the like can be used. Examples of the Ce ³⁺ activated YAG phosphor include Y ₃ Al ₅ O ₁₂ : Ce ³⁺ . Examples of Eu ²⁺ activated oxynitride phosphors include SrSi ₂ O ₂ N ₂ : Eu ²⁺ . In the second wavelength conversion layer 5, the second wavelength conversion material is dispersed in the second light transmissive material.

  The second wavelength conversion layer 5 is preferably formed in a plate shape. Thereby, the light emitting device 1a can improve the moldability of the second wavelength conversion layer 5. The second wavelength conversion layer 5 employs a rectangular plate shape as the plate shape, but is not limited thereto, and may be a circular plate shape, for example.

  The light emitting device 1 a includes, for example, a frame portion 7 disposed so as to surround the light emitting element 3 and the first wavelength conversion layer 4 on the first surface 2 a side of the mounting substrate 2, and the second wavelength conversion layer 5 is the frame portion 7. It is preferable that it is joined. As a material of the frame portion 7, for example, ceramic or metal can be used. As a result, the light emitting device 1a can easily transfer the heat generated in the second wavelength conversion layer 5 to the mounting substrate 2 via the frame portion 7, compared to the case where the material of the frame portion 7 is resin. It becomes possible to suppress a decrease in efficiency of the second wavelength conversion material. The material of the frame portion 7 is preferably a material having a small difference in linear expansion coefficient from the support 20 in the mounting substrate 2. When the support 20 is a ceramic substrate, the material of the frame portion 7 is preferably the same material as the ceramic substrate. Moreover, when the support body 20 is comprised with the metal plate and the electrically insulating layer, the material of the flame | frame part 7 has the preferable material same as a metal plate.

  In the light emitting device 1 a, the first end portion 7 a on the side close to the mounting substrate 2 in the frame portion 7 and the mounting substrate 2 are joined. In the light emitting device 1 a, the second end 7 b far from the mounting substrate 2 in the frame portion 7 and the outer peripheral portion of the second wavelength conversion layer 5 are joined. It is preferable that the second end portion 7b of the frame portion 7 and the outer peripheral portion of the second wavelength conversion layer 5 are directly joined.

  The shape of the frame portion 7 is a rectangular frame shape, but is not limited thereto, and may be a circular frame shape (cylindrical shape), for example. The shape of the frame portion 7 is preferably set based on, for example, the shape of the second wavelength conversion layer 5 and the desired light distribution characteristics of the light emitting device 1a. The light emitting device 1a may have a configuration in which a light reflection layer is formed by applying a white paint on the inner surface of the frame portion 7. As the white paint, it is preferable to employ a material having a higher reflectance to visible light than the material of the frame portion 7.

  In the light emitting device 1 a, a package 10 is configured by the mounting substrate 2, the frame unit 7, and the second wavelength conversion layer 5. In the light emitting device 1 a, the frame portion 7 is preferably bonded to the mounting substrate 2 and the second wavelength conversion layer 5 so that the airtightness of the package 10 is ensured. A part of the first conductor portion 23 exposed outside the frame portion 7 constitutes a first terminal portion 27. In addition, a part of the second conductor portion 24 exposed outside the frame portion 7 constitutes the second terminal portion 28.

  In the light emitting device 1a, the shape of the support 20 is not limited to a flat plate shape. For example, in the light emitting device 1 a, the support 20 may have a shape in which a concave portion that houses the light emitting element 3 is formed, and the peripheral wall of the concave portion may also serve as the frame portion 7. In addition, the light emitting device 1a may be configured such that the frame portion 7 protrudes integrally from the first surface 20a of the support 20. In any case, in the light emitting device 1a, it is preferable that the mounting substrate 2 and the frame portion 7 are formed of a material having a higher thermal conductivity than the second wavelength conversion layer 5.

  In the light emitting device 1a, it is preferable that the first light transmissive material is a light transmissive resin and the second light transmissive material is glass. Thereby, the light emitting device 1 a can improve the heat resistance and moisture resistance of the second wavelength conversion layer 5. Moreover, the light emitting device 1a can reduce the thermal resistance from the center of the second wavelength conversion layer 5 to the mounting substrate 2. Thereby, the light emitting device 1a can suppress a decrease in efficiency of the second wavelength conversion material of the second wavelength conversion layer 5.

  In the light emitting device 1a, it is preferable that the first wavelength conversion material is a red phosphor and the second wavelength conversion material is a yellow phosphor. Thereby, the light emitting device 1a can improve color rendering properties. For example, the light emitting device 1a employs a blue LED chip as the light emitting element 3, employs a red phosphor as the first wavelength conversion material, and employs a yellow phosphor as the second wavelength conversion material, thereby providing high color rendering properties. White light can be obtained. That is, in the light emitting device 1a, the second wavelength conversion layer 5 includes blue light emitted from the light emitting element 3, red light emitted from the red phosphor, and yellow light emitted from the yellow phosphor. It is possible to emit white light with high color rendering properties. In addition, when the light emitting device 1a employs, for example, a YAG phosphor as the yellow phosphor of the second wavelength conversion material and uses glass as the second translucent material, the second wavelength conversion layer 5 is formed. It is possible to suppress the deterioration of the second wavelength conversion material sometimes. The second light transmissive material is preferably glass having a high visible light transmittance and a low softening point. The softening point of glass is preferably about 600 ° C. or lower.

  The first wavelength conversion material is not limited to one type of red phosphor, and for example, a plurality of types of red phosphors having different emission spectra may be employed. Further, the second wavelength conversion material is not limited to one type of yellow phosphor, and for example, a plurality of types of yellow phosphors having different emission spectra may be employed. The light emitting device 1a can further enhance the color rendering by adopting a plurality of types of red phosphors as the first wavelength conversion material. In addition, the light emitting device 1a can further enhance the color rendering by adopting a plurality of types of yellow phosphors as the second wavelength conversion material.

  The heat insulating portion 6 is configured to suppress heat transfer via the mounting substrate 2 between the light emitting element 3 and the second wavelength conversion layer 5. Thereby, the light emitting device 1a can suppress the heat generated in the light emitting element 3 from being transferred to the second wavelength conversion layer 5 through the mounting substrate 2, and the efficiency of the second wavelength conversion material is reduced. Can be suppressed. Further, the light emitting device 1a can suppress the heat generated in the second wavelength conversion layer 5 from being transferred to the light emitting element 3 through the mounting substrate 2, and suppress the increase in the junction temperature of the light emitting element 3. It becomes possible to do.

  The heat insulating portion 6 is formed in a groove 25 formed in the first surface 2 a of the mounting substrate 2. The groove 25 employs a rectangular annular shape as an annular shape, but is not limited thereto, and may be, for example, an annular shape. The groove 25 is not limited to an annular shape, and a plurality of grooves 25 may be formed as a shape such as a straight line or a curved line. When the light emitting device 1 a is configured to include a plurality of grooves 25, it is preferable that the grooves 25 are formed avoiding the first conductor portion 23 and the second conductor portion 24.

  In the light emitting device 1 a, the heat insulating portion 6 is formed of a material having a lower thermal conductivity than the support 20. As a material of the heat insulating part 6, for example, a silicone resin, an acrylic resin, an epoxy resin, a polycarbonate resin, or the like can be used. The heat insulating part 6 can be formed by, for example, potting or a printing method.

  In the light emitting device 1 a described above, the second wavelength conversion layer 5 is separated from the first wavelength conversion layer 4 covering the light emitting element 3. In the light emitting device 1 a, the heat resistance of the second light transmissive material of the second wavelength conversion layer 5 is higher than the heat resistance of the first light transmissive material of the first wavelength conversion layer 4. In the light emitting device 1 a, the heat resistance of the second wavelength conversion material of the second wavelength conversion layer 5 is higher than the heat resistance of the first wavelength conversion material of the first wavelength conversion layer 4. In addition, the light emitting device 1 a includes a heat insulating portion 6 that suppresses heat transfer through the mounting substrate 2 between the light emitting element 3 and the second wavelength conversion layer 5. The light emitting device 1 a includes the first wavelength conversion layer 4 and the second wavelength conversion layer 5, so that the color rendering properties can be improved. The light emitting device 1a is formed of a mixture of a second light transmissive material having higher heat resistance than the first light transmissive material and a second wavelength conversion material having higher heat resistance than the first wavelength conversion material. The second wavelength conversion layer 5 is disposed away from the first wavelength conversion layer 4 covering the light emitting element 3, and further includes a heat insulating portion 6. Thereby, the light emitting device 1a can reduce the amount of heat generated in the vicinity of the light emitting element 3, and can suppress the increase in the junction temperature of the light emitting element 3 and the temperature quenching of the first wavelength conversion material. Therefore, since the light emitting device 1a can supply a larger current to the light emitting element 3, it is possible to increase the light output.

  2A and 2B show a light emitting device 1b of a first modification of the light emitting device 1a. The light emitting device 1b has substantially the same basic configuration as the light emitting device 1a, and the mounting form of the light emitting element 3 is different. In addition, in the light-emitting device 1b, about the component similar to the light-emitting device 1a, the code | symbol same as the light-emitting device 1a is attached | subjected and description is abbreviate | omitted.

  In the light emitting device 1b, the light emitting element 3 is bonded to the mounting substrate 2 via a bonding portion (not shown). Thus, in the light emitting device 1b, the light emitting element 3 is mechanically connected to the mounting substrate 2.

  In the light emitting device 1 b, the first electrode 33 of the light emitting element 3 and the first conductor portion 23 of the mounting substrate 2 are electrically connected via the first wire 83. In the light emitting device 1 b, the second electrode 34 of the light emitting element 3 and the second conductor portion 24 of the mounting substrate 2 are electrically connected via the second wire 84. As the 1st wire 83 and the 2nd wire 84, a gold wire, a silver wire, a copper wire, an aluminum wire etc. are employable, for example.

  In the light emitting device 1b, the light emitting element 3 is bonded to the mounting region of the light emitting element 3 on the support 20 via a bonding portion.

  When the ceramic substrate is employed as the support 20 in the light emitting device 1b, it is preferable to employ, for example, a silicone resin, an epoxy resin, a hybrid material of a silicone resin and an epoxy resin, or the like as a material for the joint portion. Thereby, the light emitting device 1b can also make a part of the light emitted from the light emitting element 3 enter the ceramic substrate through the joint.

  The light emitting device 1b may be configured to be joined to a metal plate that constitutes a part of the support 20 via a joint. Thereby, in the light emitting device 1b, a heat transfer path for transferring the heat generated in the light emitting element 3 to the metal plate without passing through the electric insulating layer is formed as a heat transfer path of the heat generated in the light emitting element 3. . Therefore, the light emitting device 1b can improve heat dissipation.

  The light emitting device 1b may have a configuration in which the light emitting element 3 is mounted on a metal plate via a plate-like submount member (not shown). The material of the submount member is preferably a material having a higher thermal conductivity than the electrical insulating layer and a smaller difference in linear expansion coefficient from the light emitting element 3 than the metal plate. Thereby, the light-emitting device 1b transfers the heat generated in the light-emitting element 3 to the submount member and the metal plate without passing through the electrical insulating layer as the heat-transfer path of the heat generated in the light-emitting element 3. Is formed. Therefore, the light emitting device 1b can improve heat dissipation. As a material of the submount member, for example, AlN can be adopted. What is necessary is just to join a submount member and a metal plate via a junction part. As a material for the joining portion that joins the submount member and the metal plate, for example, lead-free solder such as AuSn or SnAgCu is preferable. When the light-emitting device 1b employs AuSn as a material for the joining portion that joins the submount member and the metal plate, before the metal layer made of Au or Ag is formed on the joining surface of the surface of the metal plate at the time of manufacture. Processing is required.

  FIG. 3 is a schematic cross-sectional view showing a light emitting device 1c of a second modification of the light emitting device 1a. The light emitting device 1c has substantially the same basic configuration as the light emitting device 1a, and the configuration of the heat insulating portion 6 is different. In addition, in the light-emitting device 1c, about the component similar to the light-emitting device 1a, the code | symbol same as the light-emitting device 1a is attached | subjected and description is abbreviate | omitted.

  The light emitting device 1 c is formed in a tapered shape in which the first end portion 7 a on the mounting substrate 2 side in the frame portion 7 becomes narrower as it approaches the first surface 2 a of the mounting substrate 2. Thus, in the light emitting device 1 c, the frame portion 7 is in linear contact with the first surface 2 a of the mounting substrate 2, and the first end portion 7 a of the frame portion 7 also serves as the heat insulating portion 6. Therefore, the light emitting device 1 c can be reduced in cost as compared with the case where the heat insulating portion 6 is formed separately from the frame portion 7.

  In the light emitting device 1c, the first end portion 7a of the frame portion 7 has a tapered shape. However, the present invention is not limited thereto, and for example, a plurality of concave portions are provided in the first end portion 7a, and a resin is embedded in each concave portion. The heat insulating part 6 may be formed.

  FIG. 4 is a schematic cross-sectional view showing a light emitting device 1d of a third modification of the light emitting device 1a. The light emitting device 1d has substantially the same basic configuration as the light emitting device 1a, and the shape of the frame portion 7 is different. In the light emitting device 1d, the same components as those of the light emitting device 1a are denoted by the same reference numerals as those of the light emitting device 1a, and description thereof is omitted.

  In the light emitting device 1d, the shape of the frame portion 7 is formed in a tapered cylindrical shape in which the opening area gradually increases as the distance from the first surface 2a of the mounting substrate 2 increases. Accordingly, the light emitting device 1d can also use the frame portion 7 as a reflector that reflects the light from each of the light emitting element 3 and the first wavelength conversion layer 4 to the second wavelength conversion layer 5 side. The frame portion 7 employs a tapered rectangular tube shape as the tapered tube shape, but is not limited thereto, and may be a tapered cylinder shape, for example.

  The light emitting device 1d can improve the light extraction efficiency compared to the light emitting device 1a because the frame portion 7 also serves as a reflector.

  FIG. 5 is a schematic cross-sectional view showing a light emitting device 1e of a fourth modification of the light emitting device 1a. The light emitting device 1e has substantially the same basic configuration as the light emitting device 1a. In addition, in the light-emitting device 1e, about the component similar to the light-emitting device 1a, the code | symbol same as the light-emitting device 1a is attached | subjected and description is abbreviate | omitted.

  In the light emitting device 1 e, the second wavelength conversion layer 5 is located inside the outer peripheral line of the projection region in the thickness direction of the light emitting element 3. In the light emitting device 1e, the shape of the frame portion 7 is formed in a reverse tapered cylindrical shape in which the opening area gradually decreases as the distance from the first surface 2a of the mounting substrate 2 increases. The frame portion 7 adopts a reverse tapered square cylindrical shape as a reverse tapered cylindrical shape, but is not limited thereto, and may be, for example, a reverse tapered cylindrical shape.

  Since the light emitting device 1e has a light emitting area smaller than that of the light emitting device 1a, when applied to a lighting device or the like, light distribution control by a reflector or a lens becomes easier and the light distribution angle can be made smaller. It becomes possible. Therefore, the illumination device to which the light emitting device 1e is applied can irradiate light on the external irradiated surface in a spot manner.

(Embodiment 2)
Below, the light-emitting device 1f of this embodiment is demonstrated based on Fig.6 (a) and (b).

  The light emitting device 1f is different from the light emitting device 1a of the first embodiment (see FIGS. 1A and 1B) in that a plurality of light emitting elements 3 are provided on the first surface 2a side of the mounting substrate 2. In the light emitting device 1f, the same components as those of the light emitting device 1a are denoted by the same reference numerals as those of the light emitting device 1a, and description thereof is omitted.

  Since the light emitting device 1f includes the plurality of light emitting elements 3 on the first surface 2a side of the mounting substrate 2, the light output of the light emitting device 1f can be increased.

  The light emitting device 1f can have a configuration in which a plurality of light emitting elements 3 are arranged in an array. For example, as illustrated in FIG. 6A, the light-emitting device 1 f may have a configuration in which a plurality of light-emitting elements 3 are arranged in a two-dimensional array.

  In the light emitting device 1f, a plurality of light emitting elements 3 are connected in series. The light-emitting device 1 f employs a connection form in which a plurality of light-emitting elements 3 are connected in series as an electrical connection form of the plurality of light-emitting elements 3, but is not limited to this. Alternatively, a connection form connected in parallel may be adopted. The mounting substrate 2 only needs to include the first conductor portion 23 and the second conductor portion 24 formed in a predetermined pattern based on the connection form of the plurality of light emitting elements 3.

  FIG. 7 is a schematic cross-sectional view showing a light emitting device 1g of a first modification of the light emitting device 1f. The basic configuration of the light emitting device 1g is substantially the same as that of the light emitting device 1f. In the light emitting device 1g, the same components as those of the light emitting device 1f are denoted by the same reference numerals as those of the light emitting device 1f, and description thereof is omitted.

  The light emitting device 1 g includes a plurality of light emitting elements 3 on the first surface 2 a side of the mounting substrate 2, and only some of the light emitting elements 3 among the plurality of light emitting elements 3 are covered with the first wavelength conversion layer 4. Thereby, the light emitting device 1g can improve the efficiency as compared with the light emitting device 1f.

  FIG. 8 is a schematic cross-sectional view showing a light emitting device 1h of a second modification of the light emitting device 1f. The light emitting device 1h has substantially the same basic configuration as the light emitting device 1f, and the shape of the frame portion 7 is different. In the light emitting device 1h, the same components as those of the light emitting device 1f are denoted by the same reference numerals as those of the light emitting device 1f, and description thereof is omitted.

  In the light emitting device 1h, the second wavelength conversion layer 5 is positioned on the inner side of the outermost line of the projection region in the thickness direction of the mounting substrate 2 having the smallest convex polygon that includes all of the plurality of light emitting elements 3. Yes. The convex polygon is a square, but is not limited to this, and may be, for example, a rectangle or a hexagon. In the light emitting device 1h, the shape of the frame portion 7 is formed in a reverse tapered cylindrical shape in which the opening area gradually decreases as the distance from the first surface 2a of the mounting substrate 2 increases. The frame portion 7 adopts a reverse tapered square cylindrical shape as a reverse tapered cylindrical shape, but is not limited thereto, and may be, for example, a reverse tapered cylindrical shape.

  Since the light emitting device 1h has a light emitting area smaller than that of the light emitting device 1f, when applied to a lighting device or the like, light distribution control by a reflector or a lens becomes easier and the light distribution angle can be made smaller. It becomes possible. Therefore, the illumination device to which the light emitting device 1f is applied can irradiate light on the external irradiated surface in a spot manner.

  By the way, the light emitting devices 1a to 1h can be used as light sources of various lighting devices. As the lighting device, for example, a lighting device in which any one of the light emitting devices 1a to 1h is used as a light source and a lamp (for example, a straight tube type LED lamp, a light bulb type lamp) or the like can be preferably cited. However, other lighting devices may be used.

  In the light emitting devices 1a to 1h, the light emitting element 3 is provided with the first electrode 33 and the second electrode 34 provided on one surface side in the thickness direction, but is not limited thereto. As the light emitting element 3, a structure in which the first electrode 33 is formed on one surface side in the thickness direction of the light emitting element 3 and the second electrode 34 is formed on the other surface side may be used.

  Moreover, although the light emitting devices 1a to 1h employ the LED chip 30 as the light emitting element 3, the present invention is not limited thereto, and for example, an LD chip may be employed.

  Each figure described in the above-described first and second embodiments is schematic, and the ratio of the size and thickness of each component does not necessarily reflect the actual dimensional ratio. . In addition, the materials, numerical values, and the like described in the first and second embodiments are merely preferable examples and are not limited thereto. Furthermore, the present invention can be appropriately modified in configuration without departing from the scope of its technical idea.

1a, 1b, 1c, 1d, 1e, 1f, 1g, 1h Light emitting device 2 Mounting substrate 2a First surface 3 Light emitting element 4 First wavelength conversion layer 5 Second wavelength conversion layer 6 Heat insulation portion

Claims (7)

A mounting substrate, a light emitting element mounted on the first surface side of the mounting substrate, a first wavelength conversion layer covering the light emitting element, and a side opposite to the light emitting element side in the first wavelength conversion layer A second wavelength conversion layer disposed away from the first wavelength conversion layer,
The first wavelength conversion layer is a mixture of a first light-transmitting material and a first wavelength conversion material that converts a part of the light emitted from the light emitting element to emit light of a different wavelength. Formed,
The second wavelength conversion layer is a mixture of a second translucent material and a second wavelength conversion material that converts a part of light emitted from the light emitting element to emit light of different wavelengths. Formed, and the second light transmissive material has higher heat resistance than the first light transmissive material, the second wavelength conversion material has higher heat resistance than the first wavelength conversion material,
A heat insulating part that suppresses heat transfer through the mounting substrate between the light emitting element and the second wavelength conversion layer;
A light emitting device characterized by that. The first translucent material is a translucent resin, and the second translucent material is glass.
The light-emitting device according to claim 1. The first wavelength conversion material is a red phosphor, and the second wavelength conversion material is a yellow phosphor.
The light-emitting device according to claim 1 or 2. The second wavelength conversion layer is formed in a plate shape,
The light-emitting device according to any one of claims 1 to 3. A plurality of the light emitting elements on the first surface side of the mounting substrate;
Of the plurality of light emitting elements, only some of the light emitting elements are covered with the first wavelength conversion layer,
The light emitting device according to claim 1, wherein the light emitting device is a light emitting device. The second wavelength conversion layer is located inside the outer peripheral line of the projection region in the thickness direction of the light emitting element,
The light emitting device according to claim 1, wherein the light emitting device is a light emitting device. The second wavelength conversion layer is located on the inner side of the outermost line of the projection region in the thickness direction of the mounting substrate of the smallest convex polygon containing all of the plurality of light emitting elements.
The light-emitting device according to claim 5.

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