Light emitting device

Patent metadata

Field	Value
Publication number	US-9634216-B2
Application number	US-201414911162-A
Country	US
Kind code	B2
Filing date	Aug 8, 2014
Priority date	Aug 9, 2013
Publication date	Apr 25, 2017
Grant date	Apr 25, 2017

Abstract

According to one embodiment of the present invention, the light emitting device includes an LED element, a side wall which surrounds the LED element, a phosphor layer which is fixed to the side wall with an adhesive layer therebetween, and is positioned above the LED element, and a metal pad as a heat dissipating member. The side wall includes an insulating base which surrounds the LED element and a metal layer which is formed on a side surface at the LED element side of the base, and is in contact with the metal pad and the adhesive layer. The adhesive layer includes a resin layer that includes a resin containing particles which have higher thermal conductivity than the resin or a layer that includes solder.

First claim

The invention claimed is:

1. A light-emitting device, comprising:
a light-emitting element that emits a light with a peak wavelength of not more than 480 nm;
a phosphor layer that is operable to convert a wavelength of the light emitted from the light-emitting element; and
a heat dissipating member that dissipates heat generated in the phosphor layer,
wherein the phosphor layer comprises a layer comprising a single crystal phosphor, a ceramic phosphor, a glass including a phosphor particle, a layer comprising a transparent substrate and a phosphor particle-including resin layer formed thereon,

wherein the phosphor layer comprises a layer covering upper and lateral sides of the light-emitting element and being directly connected to the heat dissipating member, or a layer covering the upper side of the light-emitting element and being connected via an adhesive layer to a sidewall surrounding the light-emitting element,
wherein the sidewall comprises a first sidewall or a second sidewall,
wherein the first sidewall comprises an insulating base surrounding the LED element and a metal layer that is formed on a side surface at the LED side of the base and is in contact with the heat dissipating member and the adhesive layer,
wherein the second sidewall comprises a ceramic or a metal in contact with the heat dissipating member and the adhesive layer, and
wherein the adhesive layer comprises a resin layer comprising a resin and a particle having a higher thermal conductivity than the resin, or a layer comprising a solder.

2. The light-emitting device according to claim 1 , wherein the phosphor layer comprises a layer connected to the sidewall via the adhesive layer,
wherein the heat dissipating member comprises a metal pad to be electrically connected to the light-emitting element, and
wherein the sidewall comprises the first sidewall, or the second sidewall comprising the ceramic.

3. The light-emitting device according to claim 1 , wherein the phosphor layer comprises a layer connected to the sidewall via the adhesive layer,
wherein the sidewall comprises the second sidewall comprising the metal, and
wherein the light-emitting element is insulated from the heat dissipating member.

4. The light-emitting device according to claim 1 , wherein the phosphor layer comprises a layer connected to the sidewall via the adhesive layer, and
wherein the heat dissipating member comprises a member comprising a same material as the base of the first sidewall comprising a ceramic and formed integrally with the base of the first sidewall, or a member comprising a same material as the second sidewall and formed integrally with the second sidewall.

5. The light-emitting device according to claim 1 , wherein the phosphor layer comprises a layer connected to the sidewall via the adhesive layer, and
the heat dissipating member comprises a reflector that is in contact with the base of the first sidewall comprising a ceramic or with the second sidewall and has an opening above the light-emitting element.

6. The light-emitting device according to claim 1 , wherein the heat dissipating member comprises a heat sink located under the light-emitting element.

7. The light-emitting device according to claim 1 , further comprising a light-emitting element-heat dissipating member to dissipate heat of the light-emitting element,
wherein the heat dissipating member is thermally separated from the light-emitting element-heat dissipating member.

8. The light-emitting device according to claim 1 , wherein a base material of the transparent substrate comprises glass, gallium oxide, zinc oxide, sapphire, silicon carbide or diamond.

9. The light-emitting device according to claim 1 , wherein the transparent substrate has a thermal conductivity of not less than 1 W/(m·K) and a transmittance of not less than 80% with respect to an emission wavelength of the light-emitting element and a fluorescence wavelength.

10. The light-emitting device according to claim 1 , wherein the phosphor particles comprise a particle of a single crystal phosphor.

11. The light-emitting device according to claim 1 , wherein the phosphor layer comprises a layer connected to the sidewall via the adhesive layer, wherein the phosphor layer comprises a metal film on a surface at a portion in contact with the adhesive layer, and
wherein the adhesive layer comprises a solder.

12. The light-emitting device according to claim 1 , wherein the phosphor layer comprises a layer connected to the sidewall via the adhesive layer, and
wherein the phosphor layer comprises a concavo-convex pattern that has a depth of not less than 10% of a thickness of the phosphor layer and is formed on a surface on the light-emitting element side at a portion in contact with the adhesive layer.

13. The light-emitting device according to claim 1 , wherein the phosphor layer comprises a layer connected to the sidewall via the adhesive layer, and
wherein the sidewall is fixed to the heat dissipating member by a screw.

14. The light-emitting device according to claim 1 , wherein the phosphor layer comprises a layer connected to the sidewall via the adhesive layer, and
wherein the adhesive layer has a thermal conductivity of not less than 3 W/(m·K).

15. The light-emitting device according to claim 1 , wherein the phosphor layer comprises a layer directly connected to the heat dissipating member, and
wherein the light-emitting device further comprises a structure that the lower portion of the phosphor layer is fitted to a groove formed on an upper surface of the heat dissipating member, a structure that a threaded groove formed on a side surface of the groove on the upper surface of the heat dissipating member is screw-fixed to a threaded groove formed on a side surface of the lower portion of the phosphor layer, or a structure that a threaded groove formed on the side surface of the upper portion of the heat dissipating member is screw-fixed to a threaded groove formed on an inner side surface of the lower portion of the phosphor layer.

16. The light-emitting device according to claim 1 , wherein a radiation flux density of light emitted from the light-emitting element and incident on the phosphor layer is not less than 1.8 W/cm 2 .

17. The light-emitting device according to claim 1 , wherein a rate of an area of the lower surface of the phosphor layer at a portion in contact with the adhesive layer with respect to an area of a region contributing to wavelength conversion is not less than 35%.

18. The light-emitting device according to claim 17 , wherein the rate is not less than 70%.

19. The light-emitting device according to claim 1 , wherein the phosphor layer is a layer comprising a transparent substrate and a phosphor particle-including resin layer formed thereon, and
wherein a mass concentration of the phosphor particles in the resin layer is not less than 50 mass %.

20. The light-emitting device according to claim 19 , wherein the mass concentration is not less than 57 mass %.

Assignees

• Koha Co Ltd
• Tamura Seisakusho Kk
• Nat Inst For Materials Science

Inventors

• Inomata Daisuke
• Sano Hiroaki
• Yoshida Seitaro
• Aoki Kazuo
• Shimamura Kiyoshi
• Garcia Villora Encarnacion Antonia

Classifications

• H10W90/756

  between a chip and a stacked lead frame, conducting package substrate or heat sink · CPC title

• H10W90/754

  between a chip and a stacked insulating package substrate, interposer or RDL · CPC title

• H10W90/736

  between a chip and a stacked lead frame, conducting package substrate or heat sink · CPC title

• H10W90/734

  between a chip and a stacked insulating package substrate, interposer or RDL · CPC title

• H10W90/00

  Package configurations · CPC title