Method for manufacturing light emitting device

• US 9,660,151 B2
• Filed: 05/19/2015
• Issued: 05/23/2017
• Est. Priority Date: 05/21/2014
• Status: Active Grant

• Current Assignee: Nichia Corporation
• Original Assignee: Nichia Corporation
• Inventors: Tamaki, Hiroto
• Primary Examiner(s): Niu, Xinning
• Assistant Examiner(s): Vu, Vu A
• Application Number:
  US14/716,627
• Publication Number:
  US 20150340547A1
• Time in Patent Office: 735 Days
• Field of Search: 438 29
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48257 connecting the wire to a die pad of the item
• CPC Class Codes: H01L 2224/73253 Bump and layer connectors
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/16195 Flat cap [not enclosing an internal cavity]
• CPC Class Codes: H01L 2933/0041 relating to wavelength conversion elements
• CPC Class Codes: H01L 33/502 Wavelength conversion materials
• CPC Class Codes: H01L 33/504 Elements with two or more wavelength conversion materials

Abstract

A method for manufacturing a light emitting device has: forming a first phosphor layer including a first phosphor that is based on KSF or quantum dots on a light emitting element by a method other than spraying, and forming a second phosphor layer including a second phosphor that is different from the first phosphor on the first phosphor layer by spraying.

Claims

1. A method for manufacturing a light emitting device comprising:

mounting a light emitting element on a base member;

forming a light blocking member after the mounting of the light emitting element to cover at least a side surface of the light emitting element such that the light blocking member contacts with at least a part of the side surface of the light emitting element, the light blocking member including a resin;

forming a first phosphor layer after the forming of the light blocking member, the first phosphor layer including a first phosphor that is based on KSF or quantum dots on the light emitting element by a method other than spraying; and

forming a second phosphor layer including a second phosphor that is different from the first phosphor on the first phosphor layer by spraying.

2. The method of manufacturing the light emitting device according to claim 1, wherein

the second phosphor is a phosphor with higher hardness than that of the first phosphor.

3. The method of manufacturing the light emitting device according to claim 1, wherein

the first phosphor layer is formed by potting.

4. The method of manufacturing the light emitting device according to claim 1, wherein

the second phosphor is a phosphor with better weather resistance than that of the first phosphor.

5. The method of manufacturing the light emitting device according to claim 1, wherein

the first phosphor further includes at least one selected from the group consisting of materials based on CaS, SrGa₂S₄, SrAl₂O₄ and CASN, and the second phosphor is at least one selected from the group consisting of materials based on garnet, β

-SiAlON and chlorosilicate.

6. The method of manufacturing the light emitting device according to claim 1, wherein

the second phosphor is a phosphor with higher water resistance than that of the first phosphor.

7. The method of manufacturing the light emitting device according to claim 1, wherein

a concentration of the first phosphor contained in the first phosphor layer is less than a concentration of the second phosphor contained in the second phosphor layer.

8. The method of manufacturing the light emitting device according to claim 1, wherein

the first phosphor and the second phosphor are in the form of particles, and the first phosphor has an average particle size that is larger than the average particle size of the second phosphor.

9. The method of manufacturing the light emitting device according to claim 1, wherein

a thickness of the first phosphor layer is more than a thickness of the second phosphor layer.

10. The method of manufacturing the light emitting device according to claim 1, wherein

a thickness of the first phosphor layer is 200 μ

m or less, and a thickness of the second phosphor layer is 100 μ

m or less.

11. The method of manufacturing the light emitting device according to claim 1, wherein the forming of the light blocking member includes forming the light blocking member before the forming of the first phosphor layer, the light blocking member has a recess which exposes the light emitting element, and

the forming of the first phosphor layer includes forming the first phosphor layer on the light emitting element exposed via the recess.

12. The method of manufacturing the light emitting device according to claim 11, wherein

the forming of the light blocking member includes forming the light blocking member to cover side surfaces of the light emitting element.

13. The method of manufacturing the light emitting device according to claim 11, wherein

the forming of the first phosphor layer includes forming the first phosphor layer such that the sides of the first phosphor layer are covered by the light blocking member.

14. The method of manufacturing the light emitting device according to claim 11, wherein

the forming of the second phosphor layer includes forming the second phosphor layer to cover an upper surface of the light blocking member.

15. The method of manufacturing the light emitting device according to claim 11, wherein the forming of the light blocking member includes:

forming the light blocking member to a height that covers the light emitting element, and

selectively-removing part of an upper surface of the light blocking member to expose an upper surface of the light emitting element, whereby forming the recess which exposes the light emitting element.

16. The method of manufacturing the light emitting device according to claim 1, further comprising

preparing a substrate including a base material provided with connection terminals that are electrically connected to the light emitting element, and

mounting the light emitting element on the substrate.

17. The method of manufacturing the light emitting device according to claim 1, wherein

the first phosphor and the second phosphor are in the form of particles

an average particle size of the first phosphor and the second phosphor is 30 μ

m or less.

18. The method of manufacturing the light emitting device according to claim 1, wherein

the first phosphor layer is formed with the first phosphor and a binder such that the concentration of the first phosphor at a position near the light emitting element is higher than that at other positions far from the light emitting element in the thickness direction of the first phosphor layer, and

the second phosphor layer is formed such that the concentration in which the second phosphor is contained in the second phosphor layer is substantially uniform.

19. The method of manufacturing the light emitting device according to claim 1, wherein

the second phosphor layer is formed by laminating a plurality of layers.