Method of manufacturing light-emitting device including sealing materials with phosphor particles

• US 10,461,225 B2
• Filed: 02/25/2016
• Issued: 10/29/2019
• Est. Priority Date: 03/09/2015
• Status: Active Grant

• Current Assignee: Toyoda Gosei Company Limited (Toyota Motor Corporation)
• Original Assignee: Toyoda Gosei Company Limited (Toyota Motor Corporation)
• Inventors: Morimura, Yuta, Ito, Yuhki
• Primary Examiner(s): Ahmadi, Mohsen
• Assistant Examiner(s): Bauman, Scott E
• Application Number:
  US15/054,040
• Publication Number:
  US 20160268485A1
• Time in Patent Office: 1,342 Days
• Field of Search: 438 27, 257 98
• CPC Class Codes: H01L 2224/48091 Arched
• 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 2924/181 Encapsulation
• CPC Class Codes: H01L 2933/0041 relating to wavelength conversion elements
• CPC Class Codes: H01L 33/501 characterised by the materials, e.g. binder
• CPC Class Codes: H01L 33/504 Elements with two or more wavelength conversion materials
• CPC Class Codes: H01L 33/508 having a non-uniform spatial arrangement or non-uniform concentration, e.g. patterned wavelength conversion layer, wavelength conversion layer with a concentration gradient of the wavelength conversion material
• CPC Class Codes: H05B 33/04 Sealing arrangements , e.g. against humidity
• CPC Class Codes: H05B 33/10 Apparatus or processes specially adapted to the manufacture of electroluminescent light sources

Abstract

A method of manufacturing a light-emitting device includes providing a case including a recessed portion and mounting a light-emitting element on a bottom of the recessed portion, putting a first sealing material including a first phosphor particle into the recessed portion, putting a second sealing material including a second phosphor particle on the first sealing material in the recessed portion, and precipitating the second phosphor particle before the second sealing material cures. The second phosphor particle is located above the first phosphor particle after the first and second sealing materials cure.

Claims

1. A method of manufacturing a light-emitting device, the method comprising:

providing a case comprising a recessed portion and mounting a light-emitting element on a bottom of the recessed portion;

putting a first sealing material comprising a first phosphor particle into the recessed portion;

putting a second sealing material comprising a second phosphor particle on the first sealing material in the recessed portion;

precipitating the second phosphor particle before curing the second sealing material; and

curing the first sealing material and the second sealing material after the precipitating of the second phosphor particle,

wherein the second phosphor particle is located above the first phosphor particle after the first and second sealing materials cure,

wherein the precipitating of the second phosphor particle is conducted so as to form a layer of the second phosphor particle at a bottom of the second sealing material before the curing of the first sealing material and the second sealing material, and

wherein the first phosphor particle and the second phosphor particle are different in a degree of precipitation.

2. The method according to claim 1, wherein the second phosphor particle is completely precipitated before the second sealing material cures.

3. The method according to claim 1, wherein the first sealing material comprises a dispersant that improves dispersibility of the first phosphor particle.

4. The method according to claim 1, wherein the first sealing material has a lower refractive index than a top layer of the light-emitting element, and

wherein the second sealing material has a lower refractive index than the first sealing material.

5. The method according to claim 1, wherein the first phosphor particle has a longer fluorescence wavelength than the second phosphor particle.

6. The method according to claim 1, wherein the second sealing material has a lower refractive index than the first sealing material.

7. The method according to claim 1, wherein the precipitating the second phosphor particle comprises precipitating the second phosphor particle on an interface between the first sealing material and the second sealing material.

8. The method according to claim 1, further comprising:

heating the first sealing material to cure the first sealing material.

9. The method according to claim 8, further comprising:

after the second phosphor particle precipitates and an upper portion of the second sealing material becomes transparent, heating the second sealing material to cure the second sealing material.

10. The method according to claim 1, wherein said curing the first sealing material and the second sealing material is conducted such that opposing surfaces of the first sealing material and the second sealing material directly contact each other in an interface between the first sealing material and the second sealing material.

11. A method of manufacturing a light-emitting device, the method comprising:

disposing a first sealing material comprising a first phosphor particle into a case that holds a light-emitting element;

disposing a second sealing material comprising a second phosphor particle on the first sealing material in the case;

precipitating the second phosphor particle before curing the second sealing material; and

curing the first sealing material and the second sealing material after the precipitating of the second phosphor particle,

wherein the second phosphor particle is located above the first phosphor particle after the first and second sealing materials cure,

wherein the precipitating of the second phosphor particle is conducted so as to form a layer of the second phosphor particle at a bottom of the second sealing material before the curing of the first sealing material and the second sealing material, and

wherein the first phosphor particle and the second phosphor particle are different in a degree of precipitation.

12. The method according to claim 11, wherein the second phosphor particle is completely precipitated before the second sealing material cures.

13. The method according to claim 11, wherein the first sealing material has a lower refractive index than a superficial layer of the light-emitting element.

14. The method according to claim 11, wherein the second sealing material has a lower refractive index than the first sealing material.

15. The method according to claim 11, wherein the precipitating the second phosphor particle comprises precipitating the second phosphor particle on an interface between the first sealing material and the second sealing material.

16. The method according to claim 11, further comprising:

heating the first sealing material to cure the first sealing material.

17. The method according to claim 16, further comprising:

after the second phosphor particle precipitates and an upper portion of the second sealing material becomes transparent, heating the second sealing material to cure the second sealing material.

18. The method according to claim 11, wherein the first phosphor particle has a longer fluorescence wavelength than the second phosphor particle.