Molded chip fabrication method and apparatus

• US 9,105,817 B2
• Filed: 03/13/2014
• Issued: 08/11/2015
• Est. Priority Date: 09/18/2003
• Status: Active Grant

• Current Assignee: Creeled Incorporated
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Ibbetson, James, Leung, Michael S, Tarsa, Eric J
• Primary Examiner(s): ARMAND, MARC ANTHONY
• Application Number:
  US14/209,652
• Publication Number:
  US 20140191259A1
• Time in Patent Office: 516 Days
• Field of Search: 257/788, 438/27
• US Class Current: 1/1
• CPC Class Codes: H01L 21/565 Moulds
• CPC Class Codes: H01L 2224/2518 being disposed on at least two different sides of the body, e.g. dual array
• CPC Class Codes: H01L 24/96 the devices being encapsulated in a common layer, e.g. neo-wafer or pseudo-wafer, said common layer being separable into individual assemblies after connecting
• CPC Class Codes: H01L 27/15 including semiconductor components having potential barriers, specially adapted for light emission
• 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 2924/12041 LED
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 2924/1815 Shape
• CPC Class Codes: H01L 2933/0041 relating to wavelength conversion elements
• CPC Class Codes: H01L 33/50 Wavelength conversion elements
• CPC Class Codes: H01L 33/504 Elements with two or more wavelength conversion materials

Abstract

A method and apparatus for coating a plurality of semiconductor devices that is particularly adapted to coating LEDs with a coating material containing conversion particles. One method according to the invention comprises providing a mold with a formation cavity. A plurality of semiconductor devices are mounted within the mold formation cavity and a curable coating material is injected or otherwise introduced into the mold to fill the mold formation cavity and at least partially cover the semiconductor devices. The coating material is cured so that the semiconductor devices are at least partially embedded in the cured coating material. The cured coating material with the embedded semiconductor devices is removed from the formation cavity. The semiconductor devices are separated so that each is at least partially covered by a layer of the cured coating material. One embodiment of an apparatus according to the invention for coating a plurality of semiconductor devices comprises a mold housing having a formation cavity arranged to hold semiconductor devices. The formation cavity is also arranged so that a curable coating material can be injected into and fills the formation cavity to at least partially covering the semiconductor devices.

Claims

1. A method for fabricating a solid state light emitter, comprising:

bonding at least one light emitting diode (LED) chip to a temporary bonding media, said at least one LED chip comprising first and second contacts on at least one surface;

applying a coating to the at least one LED chip on the bonding media such that at least a portion of a surface of said contacts is not covered by said coating material; and

removing the at least one LED chip with said coating from the bonding media.

2. The method of claim 1, wherein said first and second contacts are on opposite surfaces, wherein one of said contacts is on said bonding media.

3. The method of claim 1, wherein said first and second contacts are on the same side of said LED chip, wherein both said first and said second contacts are on said bonding media.

4. The method of claim 1, wherein said at least one LED chip are flip-chip mounted on said bonding media.

5. The method of claim 1, further comprising curing the coating material.

6. The method of claim 1, further comprising curing the coating by one of the processes comprising thermal curing, optical curing and room temperature curing.

7. The method of claim 1, wherein said coating is applied by injection or otherwise introducing said coating over said LED chips.

8. The method of claim 1, wherein aid coating comprises a conformal coating.

9. The method of claim 1, wherein said coating comprises one or more conversion materials.

10. The method of claim 1, wherein said coating further comprises a binder material.

11. The method of claim 1, wherein said coating comprises multiple layers.

12. The method of claim 1, wherein said coating further comprises scattering particles.

13. The method of claim 1, wherein said bonding media comprises a polymeric material.

14. The method of claim 1, where said bonding media comprises a film or tape.

15. The method of claim 1, wherein said at least one LED chip and coating are formed into a sheet.

16. The method of claim 1, wherein said coating covers at least some light emitting surfaces of said at least one LED chip.

17. The method of claim 1, wherein said coating covers most light emitting surfaces of said at least one LED chip.

18. The method of claim 9, wherein said coating comprises a plurality of conversion materials comprising different peak emissions.

19. The method of claim 14, wherein said bonding media further comprises an adhesive.

20. The method of claim 15, wherein at least one of said at least one LED chip and coating are separated from said sheet after removal from said bonding media.

21. The method of claim 15, wherein at least one of said at least one LED chip and coating are separated from said sheet after removal from said bonding media.

22. A method for fabricating a solid state light emitter, comprising:

mounting a plurality of light emitting diode (LED) chips to a temporary bonding media, each of said LED chips comprising contacts on at least one surface;

covering said LED chips with a conversion material coating such that at least a portion of a surface of said contacts is not covered by said conversion material; and

curing said coating to form a sheet of LED chips and coating.

23. The method of claim 22, further comprising removing said sheet from said bonding media.

24. The method of claim 22, further comprising separating one or more of said LED chips and coating from said sheet.

25. The method of claim 22, wherein said LED chips are mounted to said temporary bonding media with substantially uniform distance between adjacent ones of said LED chips.

26. The method of claim 23, further comprising separating one or more LED chips and coating from said sheet after said removal of said sheet from said bonding media.

27. The method of claim 24, further comprising removing said separated LED chips and coating from said bonding media.