Light emitting device manufacturing method

• US 9,853,191 B2
• Filed: 12/09/2016
• Issued: 12/26/2017
• Est. Priority Date: 12/10/2015
• Status: Active Grant

• Current Assignee: Nichia Corporation
• Original Assignee: Nichia Corporation
• Inventors: Iwata, Hiroshi, Hosokawa, Shoji
• Primary Examiner(s): Jahan, Bilkis
• Application Number:
  US15/374,234
• Publication Number:
  US 20170170371A1
• Time in Patent Office: 382 Days
• Field of Search: None
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2933/0041 relating to wavelength conversion elements
• CPC Class Codes: H01L 2933/005 relating to encapsulations
• CPC Class Codes: H01L 2933/0058 relating to optical field-shaping elements
• CPC Class Codes: H01L 2933/0066 relating to arrangements for conducting electric current to or from the semiconductor body
• CPC Class Codes: H01L 33/504 Elements with two or more wavelength conversion materials
• CPC Class Codes: H01L 33/54 having a particular shape
• CPC Class Codes: H01L 33/56 Materials, e.g. epoxy or silicone resin
• CPC Class Codes: H01L 33/60 Reflective elements
• CPC Class Codes: H01L 33/62 Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls

Abstract

A light emitting device manufacturing method includes bonding an electrode of a light emitting element to a conductive member of a base. First wavelength conversion particles, second wavelength conversion particles and filling particles are electrodeposited on a surface of the light emitting element to form a wavelength conversion layer in which the filling particles are disposed among the first wavelength conversion particles and the second wavelength conversion particles. The first wavelength conversion particles contain aluminum. The second wavelength conversion particles have surfaces covered with covering material which contains aluminum. The filling particles contain aluminum. The filling particles have particle size smaller than particle sizes of both the first wavelength conversion particles and the second wavelength conversion particles. The filling particles have aspect ratio smaller than aspect ratios of both the first wavelength conversion particles and the second wavelength conversion particles.

Claims

1. A light emitting device manufacturing method comprising:

bonding an electrode of a light emitting element to a conductive member of a base; and

electrodepositing, on a surface of the light emitting element, first wavelength conversion particles containing aluminum, second wavelength conversion particles having surfaces covered with covering material containing aluminum, and filling particles that contain aluminum, that have particle size smaller than particle sizes of both the first wavelength conversion particles and the second wavelength conversion particles, and that have aspect ratio smaller than aspect ratios of both the first wavelength conversion particles and the second wavelength conversion particles, to form a wavelength conversion layer in which the filling particles are disposed among the first wavelength conversion particles and the second wavelength conversion particles.

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

wherein the surface of the light emitting element is covered with a first covering layer containing aluminum and being conductive, and

wherein the light emitting device manufacturing method comprises altering the first covering layer to a second covering layer which is insulate, after forming the wavelength conversion layer.

3. The light emitting device manufacturing method according to claim 1, comprising:

forming a light-transmissive resin covering the wavelength conversion layer, after forming the wavelength conversion layer.

4. The light emitting device manufacturing method according to claim 1, comprising:

forming a reflecting layer covering the wavelength conversion layer formed on the conductive member, after forming the wavelength conversion layer.

5. The light emitting device manufacturing method according to claim 1, wherein the particle size of the second wavelength conversion particles is larger than the particle size of the first wavelength conversion particles.

6. The light emitting device manufacturing method according to claim 1, wherein the aspect ratio of the second wavelength conversion particles is larger than the aspect ratio of the first wavelength conversion particles.

7. The light emitting device manufacturing method according to claim 1, wherein the particle size of the first wavelength conversion particles is in a range of 3.0 μ

m to 9.5 μ

m.

8. The light emitting device manufacturing method according to claim 1, wherein the particle size of the second wavelength conversion particles is in a range of 5.5 μ

m to 12.0 μ

m.

9. The light emitting device manufacturing method according to claim 1, wherein the particle size of the filling particles is in a range of 0.3 μ

m to 9.0 μ

m.

10. The light emitting device manufacturing method according to claim 1, wherein the aspect ratio of the filling particles is in a range of 1.0 to 1.3.

11. The light emitting device manufacturing method according to claim 1, wherein the first wavelength conversion particles are made of YAG.

12. The light emitting device manufacturing method according to claim 1, wherein a base material of the second wavelength conversion is SCASN.

13. The light emitting device manufacturing method according to claim 1, wherein the filling particles are made of aluminum oxide.

14. The light emitting device manufacturing method according to claim 1, wherein the covering material is aluminum oxide.

15. The light emitting device manufacturing method according to claim 1, wherein the first wavelength conversion particles, the second wavelength conversion particles, and filling particles are mixed to produce an electrodeposition bath liquid.

16. The light emitting device manufacturing method according to claim 15, wherein the electrode connected to the base is immersed in the electrodeposition bath liquid.