Light emitting device and method for manufacturing the same

• US 9,337,405 B2
• Filed: 08/27/2013
• Issued: 05/10/2016
• Est. Priority Date: 08/31/2012
• Status: Active Grant

• Current Assignee: Nichia Corporation
• Original Assignee: Nichia Corporation
• Inventors: Baike, Ikuko, Yamada, Takao, Suzuki, Ryo
• Primary Examiner(s): Malsawma, Lex
• Assistant Examiner(s): LE, LONG HUYNH
• Application Number:
  US14/011,628
• Publication Number:
  US 20140061704A1
• Time in Patent Office: 987 Days
• US Class Current: 1/1
• CPC Class Codes: H01L 2224/16 of an individual bump connector
• CPC Class Codes: H01L 2933/0066 relating to arrangements for conducting electric current to or from the semiconductor body
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• 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 method for manufacturing a light emitting device comprises (a) preparing a structure including a substrate, a semiconductor layer formed on the substrate, and a p-side electrode and an n-side electrode formed on the semiconductor layer; (b) preparing a support member including a p-side wiring and an n-side wiring on the same surface thereof; (c) electrically connecting the p-side electrode and the n-side electrode of the structure to the p-side wiring and the n-side wiring of the support member, respectively, using an anisotropic conductive material containing conductive particles and a first resin; and after step (c), (d) removing the substrate from the structure.

Claims

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

(a) preparing a structure including a substrate, a semiconductor layer formed on the substrate, and a p-side electrode and an n-side electrode formed on the semiconductor layer;

(b) preparing a support member including a p-side wiring and an n-side wiring on the same surface thereof;

(c) electrically connecting the p-side electrode and the n-side electrode of the structure to the p-side wiring and the n-side wiring of the support member, respectively, using an anisotropic conductive material containing conductive particles and a first resin; and

after step (c), (p) forming a light reflector that extends laterally around the anisotropic conductive material such that the light reflector is completely separated from the structure in a lateral direction by the anisotropic conductive material, the light reflector having a higher reflectivity than that of the anisotropic conductive material, and (d) removing the substrate from the structure.

2. The method for manufacturing a light emitting device according to claim 1, wherein, in step (c), the anisotropic conductive material fills a space between the structure and the support member.

3. The method for manufacturing a light emitting device according to claim 2, wherein, in step (c), the anisotropic conductive material is at least partly in contact with a side surface of the substrate.

4. The method for manufacturing a light emitting device according to claims 1, wherein, in step (d), the removal of the substrate is conducted by laser irradiation at a wavelength capable of passing through the substrate.

5. The method for manufacturing a light emitting device according to claims 1, wherein the anisotropic conductive material further contains a filler having a heat conductivity that is higher than a heat conductivity of the first resin.

6. The method for manufacturing a light emitting device according to claim 5, wherein the filler is at least one selected from the group consisting of a metal oxide, a metal nitride, and carbon.

7. The method for manufacturing a light emitting device according to claim 1, wherein step (p) is conducted before step (d).

8. The method for manufacturing a light emitting device according to claim 1, wherein the light reflector is selected from the group consisting of a layer containing a silicone-based resin and light reflective particles dispersed therein, a metal layer, and a dielectric multilayer structure.

9. The method for manufacturing a light emitting device according to claims 1, further comprising:

after step (d), (q) forming a phosphor layer on the semiconductor layer exposed by the removal of the substrate.

10. The method for manufacturing a light emitting device according to claim 9, wherein step (q) is conducted by bonding a phosphor sheet or electrodepositing a phosphor film on the semiconductor layer.

11. The method for manufacturing a light emitting device according to claim 9, further comprising:

after step (d) and before the step (q), (r) removing a part of the anisotropic conductive material that protrudes relative to a top surface of the semiconductor layer exposed by the removal of the substrate.

12. The method for manufacturing a light emitting device according to claim 9, wherein step (q) is conducted by supplying a phosphor containing resin into a recessed portion surrounded by a wall part on the semiconductor layer, and curing the phosphor containing resin, wherein the wall part corresponds to the part of the anisotropic conductive material that protrudes relative to the top surface of the semiconductor layer exposed by the removal of the substrate.

13. The method for manufacturing a light emitting device according to claims 1, further comprising:

before step (c), (s) forming bumps on the p-side electrode and the n-side electrode of the structure, or on the p-side wiring and the n-side wiring of the support member, and

wherein, in step (c), the p-side electrode and the n-side electrode of the structure are electrically connected to the p-side wiring and the n-side wiring of the support member, respectively, via the bumps using the anisotropic conductive material.

14. The method for manufacturing a light emitting device according to claim 13, wherein

in step (a), the p-side electrode and the n-side electrodes are covered with a protective film formed with openings, and

in step (s), the bumps are formed on the p-side electrode and the n-side electrode so as to be positioned in the openings of the protective film and to have their respective tops protruding relative to the protective film.

15. The method for manufacturing a light emitting device according to claims 1, wherein the conductive particles comprise a core made of a second resin, and a conductive layer covering the core and made of metal.

16. The method for manufacturing a light emitting device according to claim 15, wherein a ratio of an absolute value of a difference between a thermal expansion coefficient of the first resin and a thermal expansion coefficient of the second resin to the thermal expansion coefficient of the first resin is 1.0 or less.

17. The method for manufacturing a light emitting device according to claim 15, wherein a ratio of an absolute value of a difference between a thermal expansion coefficient of the second resin and an average thermal expansion coefficient of a material corresponding to the anisotropic conductive material from which the conductive particles are excluded, to the average thermal expansion coefficient is 1.0 or less.

18. The method for manufacturing a light emitting device according to claims 1, wherein, in step (a), the structure includes the substrate, the semiconductor layer formed on the substrate and including a n-type semiconductor layer and a p-type semiconductor layer, the n-side electrode electrically connected to the n-type semiconductor layer, the p-side electrode electrically connected to the p-type semiconductor layer, and a metal member formed on an opposite surface of the semiconductor layer to the substrate so as to overlap with the n-type-semiconductor layer and the p-type semiconductor layer.

19. The method for manufacturing a light emitting device according to claim 18, wherein the metal member is formed to overlap with the second semiconductor layer while an insulating layer is disposed therebetween.

20. The method for manufacturing a light emitting device according to claim 18, wherein the metal member corresponds to the n-side electrode formed to overlap with the second semiconductor layer.

21. The method for manufacturing a light emitting device according to claims 18, wherein a difference in height between the n-side electrode and the p-side electrode is smaller than a difference in height between the n-type semiconductor layer and the p-type semiconductor layer.

22. The method for manufacturing a light emitting device according to claims 18, wherein the support member is prepared as a collective substrate in which a plurality of support members are coupled together.

23. The method for manufacturing a light emitting device according to claim 22, further comprising:

dividing the collective substrate to obtain the light emitting device.

24. A method for manufacturing a light emitting device, the method comprising:

(a) preparing a structure including a substrate, a semiconductor layer formed on the substrate, and a p-side electrode and an n-side electrode formed on the semiconductor layer;

(b) preparing a support member including a p-side wiring and an n-side wiring on the same surface thereof;

(c) electrically connecting the p-side electrode and then-side electrode of the structure to the p-side wiring and then-side wiring of the support member, respectively, using an anisotropic conductive material containing conductive particles and a first resin, such that the anisotropic conductive material fills a space between the structure and the support member and is at least partly in contact with a side surface of the substrate; and

after step (c), (d) removing the substrate from the structure, such that a part of the anisotropic conductive material protrudes upwardly relative to a top surface of the semiconductor layer exposed by the removal of the substrate.

25. The method for manufacturing a light emitting device according to claim 24, further comprising:

after step (d), (q) forming a phosphor layer on the semiconductor layer exposed by the removal of the substrate.

26. The method for manufacturing a light emitting device according to claim 25, further comprising:

after step (d) and before step (q), (r) removing the part of the anisotropic conductive material that protrudes upwardly relative to the top surface of the semiconductor layer exposed by the removal of the substrate.

27. The method for manufacturing a light emitting device according to claim 25, wherein step (q) is conducted by supplying a phosphor containing resin into a recessed portion surrounded by a wall part on the semiconductor layer, and curing the phosphor containing resin, wherein the wall part corresponds to the part of the anisotropic conductive material that protrudes relative to the top surface of the semiconductor layer exposed by the removal of the substrate.