LIGHT-EMITTING DIES INCORPORATING WAVELENGTH-CONVERSION MATERIALS AND RELATED METHODS

• US 20130309792A1
• Filed: 02/19/2013
• Published: 11/21/2013
• Est. Priority Date: 05/21/2012
• Status: Abandoned Application

• Current Assignee: Cooledge Lighting Inc.
• Original Assignee: Cooledge Lighting Inc.
• Inventors: Tischler, Michael A., Schick, Philippe M.
• Application Number:
  US13/770,435
• Publication Number:
  US 20130309792A1
• Time in Patent Office: Days
• US Class Current: 438/28
• CPC Class Codes: H01L 22/14 for electrical parameters, e.g. resistance, deep-levels, CV, diffusions by electrical means
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2933/00 Details relating to devices covered by the group H01L33/00 but not provided for in its subgroups
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/486 adapted for surface mounting
• CPC Class Codes: H01L 33/50 Wavelength conversion elements

Abstract

In accordance with certain embodiments, light-emitting dies are fabricated on a substrate, separated from at least a portion of the substrate, and coated with a wavelength-conversion material.

Claims

1. A method of processing semiconductor devices, the method comprising:

forming a plurality of semiconductor layers on a substrate, at least some of the semiconductor layers collectively defining a light-emitting-diode (LED) structure;

forming a plurality of conductive contacts on a top surface of the semiconductor layers to define a plurality of LED dies disposed on the substrate, each of the LED dies comprising at least two of the conductive contacts on a first surface thereof;

bonding at least some of the LED dies to a temporary substrate, thereby forming a plurality of bonded LED dies each having at least two conductive contacts adjacent to the temporary substrate;

thereafter, removing the bonded LED dies from the substrate, the bonded LED dies remaining bonded to the temporary substrate;

applying a wavelength-conversion material over the bonded LED dies; and

removing the bonded LED dies from the temporary substrate.

8. The method of claim 1, wherein the substrate comprises GaAs, GaP, silicon, or sapphire.

9. The method of claim 1, wherein at least one of the semiconductor layers comprises at least one of silicon, GaAs, InAs, AlAs, InP, GaP, AlP, InSb, GaSb, AlSb, GaN, InN, AlN, SiC, ZnO, or an alloy or mixture thereof.

10. The method of claim 1, wherein bonding at least some of the LED dies to the temporary substrate comprises bonding only some of the LED dies to the temporary substrate.

11. The method of claim 1, further comprising singulating the bonded LED dies by removing, from between the bonded LED dies, at least one of (i) a portion of at least one of the plurality of semiconductor layers or (ii) a portion of the wavelength-conversion material.

12. The method of claim 11, wherein the bonded dies are singulated after removing the bonded LED dies from the temporary substrate.

13. The method of claim 11, wherein singulating the bonded LED dies comprises cutting, sawing, dicing, laser cutting, water jet cutting, or die cutting.

14. The method of claim 11, wherein the bonded dies are singulated before removing the bonded LED dies from the temporary substrate.

16. The method of claim 1, wherein removing the bonded LED dies from the substrate comprises removing at least a portion of the substrate by at least one of laser lift-off, wet chemical etching, dry etching, sand blasting, lapping, or polishing.

17. The method of claim 1, wherein forming the plurality of semiconductor layers comprises epitaxial deposition.

18. The method of claim 1, further comprising, after forming the plurality of conductive contacts, removing a portion of at least one of the semiconductor layers, thereby at least partially separating the plurality of LED dies.

19. The method of claim 18, further comprising removing a portion of the substrate.

20. The method of claim 1, wherein the substrate comprises a semiconductor substrate.

21. The method of claim 1, wherein the wavelength-conversion material comprises one or more phosphors.

22. The method of claim 21, wherein the one or more phosphors each comprise a material selected from the group consisting of YAG:

Ce, LuAG;

Ce, aluminum garnet-based phosphor, nitride-based phosphor, oxynitride-based phosphor, silicate-based phosphor, and quantum dots.

23. The method of claim 1 wherein the wavelength-conversion material comprises a material selected from the group consisting of silicone, epoxy, glass, spin-on glass, polyimide, and polymers.

26. The method of claim 1, wherein the wavelength-conversion material is applied over substantially all of each sidewall of each bonded LED die.

27. The method of claim 1, wherein each bonded LED die comprises electrical contacts only on the first surface thereof.

29. The method of claim 1, wherein applying the wavelength-conversion material comprises dispensing, casting, molding, or compression molding.

30. The method of claim 1, wherein the wavelength-conversion material comprises an encapsulant, and further comprising curing the encapsulant.

31. The method of claim 1, wherein a thickness of the wavelength-conversion material on the bonded LED dies is defined at least in part by a spacing between bonded LED dies on the temporary substrate.

32. The method of claim 1, further comprising electrically testing the bonded LED dies.

2-7. -7. (canceled)

15. The method of clam 11, further comprising transferring the bonded LED dies from the temporary substrate to a second temporary substrate prior to singulation.

24-25. -25. (canceled)

28. (canceled)

33-45. -45. (canceled)