Light emitting diode chip with electrical insulation element

• US 20100224890A1
• Filed: 09/18/2006
• Published: 09/09/2010
• Est. Priority Date: 09/18/2006
• Status: Abandoned Application

• Current Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Ibbetson, James, Keller, Bernd, Chitnis, Ashay
• Application Number:
  US11/523,381
• Publication Number:
  US 20100224890A1
• Time in Patent Office: Days
• US Class Current: 257/93
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48111 the wire connector extending above another semiconductor or solid-state body
• CPC Class Codes: H01L 2224/49107 on the semiconductor or solid-state body
• CPC Class Codes: H01L 24/48 of an individual wire connector
• CPC Class Codes: H01L 24/49 of a plurality of wire connectors
• 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 2924/00014 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 2924/01322 Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/10253 Silicon [Si]
• CPC Class Codes: H01L 2924/10272 Silicon Carbide [SiC]
• CPC Class Codes: H01L 2924/10336 Aluminium gallium arsenide [AlGaAs]
• CPC Class Codes: H01L 2924/10349 Aluminium gallium indium phosphide [AlGaInP]
• CPC Class Codes: H01L 2924/12041 LED
• CPC Class Codes: H01L 2924/19041 being a capacitor
• CPC Class Codes: H01L 33/0075 comprising nitride compounds
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating

Abstract

A light emitting diode chip comprising a light emitting diode and a thermally conductive substrate. The light emitting diode is on the substrate with the substrate providing a thermal path from the light emitting diode through the substrate. A mounting pad is also on a substrate and an electrically insulating layer is integral to the substrate. The insulating layer electrically insulates the mounting pad from the light emitting diode. A method for fabricating a light emitting diode chip comprises providing a thermally conductive substrate, forming an electrical insulating layer integral to the substrate and forming a mounting pad on the substrate. A light emitting diode is fabricated and mounted to the substrate, with the light emitting diode electrically insulated from the mounting pad by the electrically insulating layer.

Claims

1. A light emitting diode chip, comprising:

a thermally conductive substrate;

a light emitting diode on said substrate with said substrate providing a thermal path to draw heat away from said light emitting diode;

a mounting pad on said substrate; and

an electrical insulating layer integral to said LED chip, said insulating layer for electrically insulating said mounting pad from said light emitting diode and having a thickness for allowing a thermally conductive path from said light emitting diode to said mounting pad.

3. The light emitting chip of claim 1, wherein said insulating layer is between said light emitting diode and said substrate.

4. The light emitting chip of claim 1, wherein said insulating layer is between said substrate and said mounting pad.

5. The light emitting diode chip of claim 1, wherein said insulating layer comprises a dielectric material.

6. The light emitting diode chip of claim 5, wherein said insulating layer has a thickness in the range of approximately 0.1 to 5 micrometers.

7. The light emitting diode chip of claim 1, wherein said insulating layer does not substantially interfere with said substrate thermal path.

8. The light emitting diode chip of claim 1, wherein said substrate comprises silicon (Si) or silicon carbide (SiC).

9. The light emitting diode of claim 1, wherein said substrate comprises a thermally conductive dielectric substrate.

24. The solid state light of claim 1, further comprising an electrical insulating layer integral to said LED chip, said insulating layer electrically insulating said mounting pad from said light emitting diode.

25. The solid state light of claim 24, wherein said insulating layer is between said light emitting diode and said mounting pad.

26. The solid state light of claim 24, wherein said insulating layer does not substantially interfere with said substrate thermal path.

2. (canceled)

10. A light emitting diode chip, comprising:

a light emitting diode;

a semiconductor substrate, said light emitting diode on said substrate, said substrate providing a thermal path from said light emitting diode through said substrate;

a mounting pad on said substrate; and

an electrically insulating layer integral to said substrate, said insulating layer electrically insulating said mounting pad from said light emitting diode, said electrically insulating layer between said thermally conductive substrate and said mounting pad.

11. The light emitting chip of claim 10, further comprising a p-type metal layer between said light emitting diode and said thermally conductive substrate.

12. The light emitting chip of claim 11, further comprising a wafer bonding layer between said p-type metal layer and said thermally conductive substrate.

13. The light emitting diode chip of claim 10, wherein said insulating layer comprises a dielectric material.

14. The light emitting diode chip of claim 10, wherein said insulating layer is in the range of 0.1 to 5 micrometers thick.

15. The light emitting diode chip of claim 10, wherein said insulating layer does not substantially interfere with said substrate thermal path.

16. A semiconductor device chip, comprising:

a semiconductor device comprising a plurality of semiconductor layers;

a semiconductor substrate, said device on said substrate, said substrate providing a thermal path from said device through said substrate;

a mounting pad on said substrate for mounting said substrate; and

an electrically insulating layer integral to said substrate, said insulating layer electrically insulating said mounting pad from said device and having a thickness for allowing for a thermally conductive path from said semiconductor path and to said mounting pad.

17. The device chip of claim 16, wherein said insulating layer is between said device and said substrate.

18. The device chip of claim 16, wherein said insulating layer is between said substrate and said mounting pad.

19. The device chip of claim 16, wherein said insulating layer does not substantially interfere with said substrate thermal path.

20. A solid state light, comprising:

a light emitting diode chip comprising;

a thermally conductive substrate;

a light emitting diode mounted on said substrate with said substrate providing a thermal path to draw heat away from said light emitting diode; and

a mounting pad on said substrate for mounting said light emitting diode, said mounting pad electrically insulated from said light emitting diode through said substrate;

a circuit board, said light emitting diode chip mounted to said circuit board by said mounting pad; and

a p-type metal layer between said substrate and said light emitting diode, said p-type metal layer on less than all of a substrate surface.

21. The solid state light of claim 20, wherein further comprising a heat sink thermally connected to said circuit board.

22. The solid state light of claim 20, further comprising additional light emitting diode chips, each mounted to said circuit board to form an LED chip array.

23. The solid state light of claim 22, further comprising conductors, each of said LEDs having respective conductors to apply respective biases to said LEDs.

27. A method for forming a semiconductor device chip, comprising:

providing a thermally conductive substrate;

forming an electrical insulating layer integral to said substrate;

forming a mounting pad on said substrate;

fabricating a semiconductor device having a plurality of semiconductor layers; and

mounting said semiconductor device to said substrate with said substrate providing a thermal path from said semiconductor device through said substrate, with said insulating layer electrically formed to insulate said semiconductor device from said mounting pad.

28. A method for fabricating an light emitting diode chip, comprising:

providing a thermally conductive substrate;

forming an electrical insulating layer integral to said substrate;

forming a mounting pad on said substrate;

fabricating a light emitting diode;

mounting said light emitting diode to said substrate and with said light emitting diode electrically insulated from said mounting pad by said electrically insulating layer.

29. The method of claim 28, wherein said substrate provides a thermal path from said semiconductor through said substrate.

30. The method of claim 28, wherein said mounting step comprises wafer mounting.

31. The method of claim 28, wherein each of said light emitting diode and said substrate is part of a wafer, said method further comprising separating said light emitting diode chip from the remainder of said wafers.

32. The method of claim 28, comprising the further step of mounting said light emitting diode in a solid state light.

33. A light emitting diode chip, comprising:

a solderable mounting pad;

a thermally conductive carrier substrate on said mounting pad;

an electrically insulating layer on said carrier substrate opposite said mounting pad, said insulating layer having a thickness chosen such that heat can transfer readily through said insulating layer;

a p-type semiconductor layer on said insulating layer;

an n-type semiconductor layer on said p-type layer;

an active region interposed between said n-type and p-type layers;

an n-contact pad electrically contacting said n-type layer opposite said carrier substrate; and

a p-contact pad electrically contacting said p-type layer opposite said carrier substrate.

34. The light emitting diode chip of claim 33, wherein said insulating layer comprises a dielectric material.

35. The light emitting diode chip of claim 33, wherein said insulating layer has a thickness in the range of approximately 0.1 to 5 micrometers.

36. The light emitting diode of claim 33, wherein said carrier substrate comprises a thermally conductive dielectric substrate.

37. The light emitting diode of claim 33, wherein said n-type and p-type layers comprise Group III nitride materials.