Manufacturing method for light emitting device

Patent metadata

Field	Value
Publication number	US-10734556-B2
Application number	US-201916393965-A
Country	US
Kind code	B2
Filing date	Apr 25, 2019
Priority date	Jul 29, 2016
Publication date	Aug 4, 2020
Grant date	Aug 4, 2020

Abstract

A method for manufacturing a light emitting device includes disposing on lateral surfaces of the light emitting element, a first wavelength converting member containing a first phosphor to convert the first light emitted from the light emitting element into a second light having a second peak wavelength longer than the first peak wavelength. The light emitting element provided with the first wavelength converting member is disposed on a base. A second wavelength converting member is disposed on the base. The second wavelength converting member covers an upper surface of the light emitting element provided with the first wavelength converting member and lateral surfaces of the first wavelength converting member provided opposite to additional lateral surfaces of the first wavelength converting member. The additional lateral surfaces face the lateral surface of the light emitting element. The second wavelength converting member contains a second phosphor.

First claim

What is claimed is:

1. A method for manufacturing a light emitting device, comprising:
disposing on a support material, a light emitting element to emit a first light having a first peak wavelength;
disposing on lateral surfaces of the light emitting element, a first wavelength converting member containing a first phosphor to convert the first light emitted from the light emitting element into a second light having a second peak wavelength longer than the first peak wavelength;
disposing on a base, the light emitting element provided with the first wavelength converting member; and
disposing a second wavelength converting member on the base, the second wavelength converting member covering an upper surface of the light emitting element provided with the first wavelength converting member and lateral surfaces of the first wavelength converting member disposed opposite to additional lateral surfaces of the first wavelength converting member, the additional lateral surfaces facing the lateral surfaces of the light emitting element, the second wavelength converting member containing a second phosphor.

2. The method according to claim 1 ,
wherein the base has a base upper surface and a recessed portion recessed from the base upper surface, the recessed portion having an opening provided in the base upper surface and a bottom surface opposite to the opening, and
wherein the light emitting element provided with the first wavelength converting member is disposed on the bottom surface of the recessed portion.

3. The method according to claim 1 , wherein the disposing a first wavelength converting member includes
disposing an uncured first resin containing the first phosphor between a plurality of light emitting elements on the support material,
hardening the first resin, and
cutting the first resin by forming grooves penetrating in a thickness direction between the light emitting elements.

4. The method according to claim 1 , wherein the forming a second wavelength converting member includes
disposing an uncured second resin containing the second phosphor particles in a recessed portion,
forcibly settling the second phosphor particles towards the bottom surface of the recessed portion, and
hardening the second resin.

5. The method according to claim 1 , wherein the light emitting element disposed on the support material has a reflective film disposed on the surface opposite to the support material.

6. The method according to claim 1 , wherein the first wavelength converting member is not disposed on the upper surface of the light emitting element when a first wavelength converting member is disposed.

7. The method according to claim 1 , wherein the second wavelength converting member is disposed to be in contact with the upper surface of the light emitting element when a second wavelength converting member is provided.

8. The method according to claim 1 , wherein the second wavelength converting member includes a portion which covers the base and in which the second wavelength converting member has a first concentration of the second phosphor at a height of the upper surface of the light emitting element in a height direction and a second concentration of the second phosphor at a height of a lower surface of the light emitting element in the height direction, the second concentration being higher than the first concentration such that the second phosphor reflects the second light when a second wavelength converting member is provided.

9. The method according to claim 1 , wherein the second wavelength converting member includes a first portion covering the upper surface of the light emitting element and a second portion covering the base and being separated from the first portion when a second wavelength converting member is provided.

10. The method according to claim 1 , wherein the second wavelength converting member includes a first portion covering the upper surface of the light emitting element, and a second portion covering the base and being separated from the first portion such that the first wavelength converting member is exposed from the second wavelength converting member between the first portion and the second portion when a second wavelength converting member is provided.

11. The method according to claim 1 , wherein the disposing a first wavelength converting member includes
disposing a plurality of light emitting elements at prescribed intervals on the support material,
disposing the first wavelength converting member between two adjacent light emitting elements on the support material, and
cutting the first wavelength converting member such that the first wavelength converting member remains on the lateral faces of the two adjacent light emitting elements.

12. The method according to claim 11 , wherein the disposing the first wavelength converting member employs a method of applying a slurry containing particles of the first phosphor.

13. The method according to claim 12 , wherein the method of applying a slurry includes one selected from the group consisting of spraying, silk screen printing, ink jetting, potting, and spin coating.

14. The method according to claim 1 ,
wherein the second wavelength converting member has a first cross-sectional area ranging from a height of the upper surface of the light emitting element to a middle height between the upper surface and a lower surface of the light emitting element in a height direction and has a first area ratio which is a percentage of a cross-sectional area of second phosphor particles taken along a plane in the first cross-sectional area,
wherein the second wavelength converting member has a second cross-sectional area ranging from the middle height to the base in the height direction and has a second area ratio which is a percentage of a cross-sectional area of the second phosphor particles taken along a plane in the second cross-sectional area, and
wherein the second area ratio being higher than the first area ratio when a second wavelength converting member is provided.

15. The method according to claim 1 ,
wherein the light emitting element emits blue light,
wherein the first phosphor emits red light, and
wherein the second phosphor emits green to yellow light.

16. The method according to claim 1 , wherein the second wavelength converting member has a portion in which the second phosphor is disposed in a form of a layer at least in a portion where the second wavelength converting member covers the base, a thickness of the layer being equal to or lower than three quarters of a height of the light emitting element when a second wavelength converting member is provided.

17. The method according to claim 16 , wherein the second wavelength converting member, at least in the portion disposed on the base, is substantially free from the second phosphor above three quarters of the height of the light emitting element in a height direction.

18. The method according to claim 1 ,
wherein the light emitting element has a reflective film at a lower surface, and
wherein the reflective film is to reflect the first light having the first peak wavelength and transmit the second light having the second peak wavelength.

19. The method according to claim 18 , wherein the reflective film is a distributed Bragg reflector (DBR) film, which is a dielectric multilayer film to reflect the first light having the first peak wavelength of the light emitting element and to transmit the second light having the second peak wavelength.

Assignees

• Nichia Corp

Inventors

• Iwakura Daisuke

Classifications

• H10W90/756

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

• H10W90/736

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

• H10W72/07554

  changes in dispositions · CPC title

• H10W72/884

  Die-attach connectors and bond wires · CPC title

• H10W72/547

  Dispositions of multiple bond wires · CPC title