High power solid-state lamp

• US 9,412,926 B2
• Filed: 06/10/2005
• Issued: 08/09/2016
• Est. Priority Date: 06/10/2005
• Status: Active Grant

• Current Assignee: Creeled Incorporated
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Keller, Bernd, Ibbetson, James
• Primary Examiner(s): Lee, Jong-Suk (James)
• Assistant Examiner(s): Tsidulko, Mark
• Application Number:
  US11/149,999
• Publication Number:
  US 20080007953A1
• Time in Patent Office: 4,078 Days
• Field of Search: 362/294, 362/631, 362/227, 362/264, 362/373, 362/800, 165/185, 361701-704, 361/709, 361/710
• US Class Current: 1/1
• 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 33/60 Reflective elements
• CPC Class Codes: H01L 33/641 characterized by the materials
• CPC Class Codes: H01L 33/642 characterized by the shape

Abstract

A high power semiconductor component structure having a semiconductor device arranged to operate in response to an electrical signal, with the device heating up during operation in response to the electrical signal. A heat sink is positioned in thermal contact with the semiconductor device such that heat from the device transmits into the first heat sink. The heat sink has at least partially a porous material region of a thermally conductive material in a 3-dimensional pore structure with the surfaces of the pore structure providing surface area for heat to dissipate into the ambient air.

Claims

1. An optical device, comprising:

a solid state light source;

a reflector positioned to reflect light from said light source into directional light emission, heat from said light source at least partially transmitting into said reflector; and

a first heat sink mounted to said reflector positioned in thermal contact with said light source such that heat from said light source transmits into said first heat sink, said first heat sink comprising a thermally conductive conformable porous material layer adjacent said light source, said porous material layer comprising a 3-dimensional pore structure comprising interconnected pores, with the surfaces of said pore structure providing increased surface area for heat to dissipate into the ambient compared to bulk heat sinks, said porous material layer further comprising a graded porous material region wherein part of said porous material region comprises a higher density pore structure than the remainder of said region, said first heat sink shaped to fit around said reflector, wherein said reflector is configured to spread heat from said light source throughout said first heat sink;

wherein said reflector comprises a reflective metal and wherein said reflector is affixed to said first heat sink.

2. The device of claim 1, further comprising a circuit board, said light source mounted to said circuit board, and said first heat sink mounted to said circuit board such that heat from said light source transmits at least partially into said first heat sink.

3. The device of claim 1, further comprising a circuit board and a reflector, said light source and reflector mounted to said circuit board such that said reflector reflects at least some of said light from said emitter into directional light emission, and said first heat sink mounted to said circuit board such that heat from said light source transmits into said first heat sink.

4. The device of claim 3, further comprising a second heat sink mounted to said circuit board such that the light source at least partially transmits heat through said circuit board into said second heat sink.

5. The device of claim 1, wherein said porous material region further comprises a dark coating to increase radiation of heat into the ambient.

6. The device of claim 1, wherein any higher density porous region of said heat sink comprises a thermal paste infused into a portion of the porous material.

7. The device of claim 1, wherein the porous material layer comprises dimensions and porosity that provide for an optimum conductive heat transfer.

8. The device of claim 1, wherein the first heat sink is provided on an outside surface of the reflector.

9. The device of claim 1, wherein the first heat sink is bonded to an outside surface of the reflector.

10. The device of claim 9, wherein the first heat sink is bonded to the outside surface of the reflector by a conductive adhesive.

11. The device of claim 1, further comprising a heat conductive path between the first heat sink and the reflector.

12. The device of claim 1, wherein the reflector is affixed to the first heat sink by a thermally conductive adhesive.

13. An optical device, comprising:

a solid state light source; and

a first heat sink positioned in thermal contact with said light source such that heat from said light source transmits into said first heat sink, said first heat sink comprising a porous material layer adjacent said light source, said porous material comprising a thermally conductive material with a 3-dimensional pore structure comprising interconnected pores, with the surfaces of said pore structure providing increased surface area for heat to dissipate into the ambient compared to bulk heat sinks, said heat sink comprising a graded porous material region wherein part of said porous material region comprises a higher density pore structure than the remainder of said region.

14. The device of claim 13, wherein any higher density porous region of said heat sink comprises a solid metal.

15. A lamp, comprising:

a solid state light source mounted to a circuit board;

a reflector mounted to said circuit board to reflect at least some of the light from said light source into directional light emission;

contacts for providing electrical power to said solid state light source; and

first and second heat sinks, each of which comprises a layer of thermally conductive conformable porous material in a 3-dimensional pore structure comprising interconnected pores, said porous material layer comprising a graded porous material region wherein part of said porous material region comprises a higher density pore structure than the remainder of said region, said first heat sink shaped to fit around said reflector and said second heat sink affixed to and covering said circuit board, wherein said reflector is configured to spread heat from said light source throughout said first heat sink, wherein said first and second heat sinks are on opposite sides of said circuit board;

wherein said reflector comprises a reflective metal and wherein said reflector is affixed to said first heat sink.

16. The lamp of claim 15, wherein said reflector is made of a metal.

17. The lamp of claim 15, wherein at least a portion of the circuit board is between the first heat sink and the second heat sink.

18. The lamp of claim 15, wherein the porous material comprises dimensions and porosity that provide for an optimum conductive heat transfer.

19. The lamp of claim 15, wherein the first heat sink is provided on an outside surface of the reflector.

20. The lamp of claim 15, wherein the first heat sink is bonded to an outside surface of the reflector.

21. The lamp of claim 20, wherein the first heat sink is bonded to the outside surface of the reflector by a conductive adhesive.

22. The lamp of claim 15, further comprising a heat conductive path between the first heat sink and the reflector.

23. The lamp of claim 15, wherein the reflector is affixed to the first heat sink by a thermally conductive adhesive.

24. A lamp, comprising:

a solid state light source mounted to a circuit board;

a reflector mounted to said circuit board to reflect at least some of the light from said light source into directional light emission;

contacts for providing electrical power to said solid state light source; and

first and second heat sinks, each comprising a conformable porous material region made of a thermally conductive material in a 3-dimensional pore structure, wherein part of said porous material region comprises a graded region, part of said graded region comprising a higher density pore structure than the remainder of said graded region, said first heat sink shaped to fit around said reflector and said second heat sink affixed to said circuit board, said reflector comprising reflectively coated plastic and a heat conductive path comprising a heat conductive layer between said reflector and said first heat sink for heat to transmit from said light source and spread into and throughout said first heat sink through said heat conductive path, wherein said first and second heat sinks are on opposite sides of said circuit board.

25. The lamp of claim 24, wherein heat from said light source transmits into said second heat sink through said circuit board.

26. The lamp of claim 24, further comprising one or more heat conductive vias through said circuit board, said vias conducting heat from said emitter to said second heat sink.

27. The lamp of claim 26, further comprising a heat conductive layer between said second heat sink and said circuit board, said conductive layer in thermal contact with said vias and said second heat sink, and spreading heat from said vias across said heat sink.

28. The lamp of claim 24, wherein said porous material region further comprises a dark coating to increase radiation of heat into the ambient.

29. The device of claim 24, wherein at least part of the non-porous region of said heat sink comprises a solid metal.

30. The device of claim 24, wherein at least part of the non-porous region of said heat sink comprises a thermal paste infused into a porous material.

31. The device of claim 24, wherein said light source comprises one from the group consisting of a light emitting diode, a plurality of light emitting diodes, a solid state laser, and a plurality of solid state lasers.

32. The lamp of claim 24, wherein at least a portion of the circuit board is between the first heat sink and the second heat sink.

33. The lamp of claim 24, wherein the porous material region comprises dimensions and porosity that provide for an optimum conductive heat transfer.

34. The lamp of claim 24, wherein the first heat sink is provided on an outside surface of the reflector.

35. The lamp of claim 24, wherein the first heat sink is bonded to an outside surface of the reflector.

36. The lamp of claim 35, wherein the first heat sink is bonded to the outside surface of the reflector by a conductive adhesive.

37. The lamp of claim 24, wherein the reflectively coated plastic is coated with a reflective metal.

38. A lamp, comprising:

a solid state light source mounted to a circuit board;

a reflector mounted to said circuit board to reflect at least some of the light from said light source into directional light emission;

contacts for providing electrical power to said solid state light source; and

first and second heat sinks, each comprising a porous material region made of a thermally conductive material in a 3-dimensional pore structure, said first heat sink affixed to said reflector and said second heat sink affixed to said circuit board, wherein said reflector is made of reflectively coated plastic, and further comprising a heat conductive path between said reflector and said first heat sink for heat to transmit from said light source into first heat sink through said heat conductive path, said porous material region of said first or second heat sinks being graded such that part of said porous material region comprises a higher density pore structure than the remaining of said region.

39. A high power semiconductor component structure, comprising:

a semiconductor device configured to operate in response to an electrical signal, said device heating up during operation in response to said electrical signal;

a thermally conductive metal layer;

a first heat sink mounted to said thermally conductive metal layer positioned in thermal contact with said semiconductor device such that heat from said device transmits into said first heat sink, said first heat sink comprising a conformable porous material region, said porous material region comprising a thermally conductive material in a 3-dimensional pore structure comprising interconnected pores with the surfaces of said pore structure providing surface area for heat to dissipate into the ambient, wherein part of said porous material region comprises a graded region, part of said graded region comprising a higher density pore structure than the remainder of said graded region, wherein said porous material region is thermally conductive, said first heat sink shaped to fit around said thermally conductive metal layer, wherein said thermally conductive metal layer is configured to spread heat from said device throughout said first heat sink;

wherein said thermally conductive metal layer is affixed to said first heat sink; and

a second heat sink, said second heat sink comprising a conformable porous material region, said porous material region comprising a thermally conductive material in a 3-dimensional pore structure comprising interconnected pores with the surfaces of said pore structure providing surface area for heat to dissipate into the ambient, wherein said porous material region is thermally conductive.

40. The structure of claim 39, wherein said semiconductor device comprises a solid state light source, and said thermally conductive metal layer comprises a reflector positioned to reflect light from said light source into directional light emission.

41. The structure of claim 40, wherein the first heat sink is provided on an outside surface of the reflector.

42. The structure of claim 40, wherein the first heat sink is bonded to an outside surface of the reflector.

43. The structure of claim 42, wherein the first heat sink is bonded to the outside surface of the reflector by a conductive adhesive.

44. The structure of claim 40, further comprising a heat conductive path between the first heat sink and the reflector.

45. The structure of claim 39, further comprising a circuit board, said semiconductor device mounted to said circuit board, and said first heat sink mounted to said circuit board such that heat from said device transmits into said first heat sink.

46. The structure of claim 39, further comprising a circuit board and a reflector, wherein said semiconductor device comprises a solid state light source, said reflector and light source mounted to said circuit board such that said reflector reflects at least some of said light from said emitter into directional light emission.

47. The structure of claim 46, wherein said first heat sink is mounted to said circuit board such that heat from said light source transmits into said first heat sink.

48. The structure of claim 46, further comprising a second heat sink mounted to said circuit board such that the light source heat transmits into said second heat sink.

49. The structure of claim 39, wherein said semiconductor device comprises a solid state power device, and further comprising a second heat sink at least partially comprising a porous material region, said porous material region comprising a thermally conductive material in a 3-dimensional pore structure with the surfaces of said pore structure providing surface area for heat to dissipate into the ambient, said power device sandwiched between said first and second heat sinks.

50. The structure of claim 49, further comprising a circuit board, said power device mounted to said circuit board, said circuit board and power device sandwiched between said first and second heat sinks.

51. The structure of claim 39, wherein the porous material region comprises dimensions and porosity that provide for an optimum conductive heat transfer.

52. The structure of claim 39, wherein the thermally conductive metal layer is affixed to the first heat sink by a thermally conductive adhesive.

53. A high power semiconductor component structure, comprising:

a semiconductor device configured to operate in response to an electrical signal, said device heating up during operation in response to said electrical signal; and

a first heat sink covering a surface of said semiconductor device and positioned in thermal contact with said semiconductor device such that heat from said device transmits into said first heat sink, said first heat sink comprising a porous material region, said porous material region comprising a thermally conductive material in a 3-dimensional pore structure comprising interconnected pores with the surfaces of said pore structure providing surface area for heat to dissipate into the ambient, said heat sink comprising a graded porous material region wherein part of said porous material region comprises a higher density pore structure than the remaining of said region.

54. An optical device, comprising:

a solid state light source;

a reflector positioned to reflect light from said light source into directional light emission, heat from said light source at least partially transmitting into said reflector; and

a first heat sink mounted to said reflector positioned in thermal contact with said light source such that heat from said light source transmits into said first heat sink, said first heat sink comprising a thermally conductive conformable porous material layer adjacent said light source, said porous material layer further comprising a graded porous material region wherein part of said porous material region comprises a higher density pore structure than the remainder of said region, said first heat sink shaped to fit around said reflector, wherein said reflector is configured to spread heat from said light source throughout said first heat sink;

wherein said reflector comprises a reflective metal and wherein said reflector is affixed to said first heat sink.

55. The device of claim 54, further comprising a circuit board, said light source mounted to said circuit board, and said first heat sink mounted to said circuit board such that heat from said light source transmits at least partially into said first heat sink.

56. The device of claim 54, wherein the first heat sink is provided on an outside surface of the reflector.

57. The device of claim 54, wherein the first heat sink is bonded to an outside surface of the reflector.

58. The device of claim 57, wherein the first heat sink is bonded to the outside surface of the reflector by a conductive adhesive.

59. The device of claim 54, further comprising a heat conductive path between the first heat sink and the reflector.

60. The device of claim 54, wherein the reflector is affixed to the first heat sink by a thermally conductive adhesive.