COMPACT OPTICALLY EFFICIENT SOLID STATE LIGHT SOURCE WITH INTEGRATED THERMAL MANAGEMENT

• US 20130009179A1
• Filed: 07/06/2011
• Published: 01/10/2013
• Est. Priority Date: 07/06/2011
• Status: Active Grant

• Current Assignee: Creeled Incorporated
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Garceran, Julio, Keller, Bernd, BHAT, CHANDAN, Lowes, Theodore Douglas
• Granted Patent: US 10,842,016 B2
• Time in Patent Office: Days
• US Class Current: 257/89
• CPC Class Codes: F21V 19/0055 by screwing
• CPC Class Codes: F21Y 2105/10 comprising a two-dimensional array of point-like light-generating elements
• CPC Class Codes: F21Y 2105/12 characterised by the geometrical disposition of the light-generating elements, e.g. arranging light-generating elements in differing patterns or densities
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/32257 the layer connector connecting to a bonding area disposed in a recess of the surface of the item
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/73265 Layer and 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: H05K 1/0209 External configuration of printed circuit board adapted for heat dissipation, e.g. lay-out of conductors, coatings
• CPC Class Codes: H05K 1/0373 containing additives, e.g. fillers H05K1/036 takes precedence
• CPC Class Codes: H05K 2201/066 Heatsink mounted on the surface of the printed circuit board [PCB]
• CPC Class Codes: H05K 2201/10106 Light emitting diode [LED]

Abstract

A compact and efficient LED array lighting component comprising a circuit board with an array of LED chips mounted on it and electrically interconnected. A plurality of primary lenses is included, each of which is formed directly over each LED chip and/or a sub-group of the LED chips. A heat sink is included with the circuit board mounted to the heat sink so that heat from the LED chips spreads into the heat sink. In some embodiments the circuit board can be thermally conductive and electrically insulating. Method of forming an LED component are also disclosed utilizing chip-on-board mounting techniques for mounting the LED chips on the circuit board, and molding of the primary lenses directly over the LED chips individually or in sub-groups of LED chips.

Claims

1. An LED component, comprising:

a circuit board having a plurality of die attach pads;

a plurality of LED chips, each of which is mounted on a respective one of the die attach pads; and

primary lenses, each of which is formed directly over a single one or a subgroup of said LED chips.

2. The LED component of claim 1, further comprising first and second wire bond pads, said LED chips connected in series between said wire bond pads.

3. The LED component of claim 1, wherein said circuit board is electrically insulating.

4. The LED component of claim 1, wherein said circuit board is electrically insulating up to 2000 volts.

5. The LED component of claim 1, wherein said circuit board is thermally conductive.

6. The LED component of claim 1, wherein said circuit board comprises a dielectric with one or more thermally conductive materials.

7. The LED component of claim 1, wherein said circuit board further comprises a conductive base plate.

8. The LED component of claim 1, wherein said LED chips are arranged in a plurality of sub-groups.

9. The LED component of claim 8, comprising a respective one of said primary lenses over each sub-group.

10. The LED component of claim 1, wherein said lenses are substantially hemispheric shaped.

11. The LED component of claim 1, wherein said LED chips are arranged in a circle on said circuit board.

12. The LED component of claim 1, wherein said LED chips are arranged in concentric circles.

13. The LED component of claim 12, wherein said LED chips are interconnected in a zig-zag arrangement.

14. The LED component of claim 1, wherein said LED chips are set-back from the edge of said circuit board.

15. The LED component of claim 1, wherein said LED chips are mounted on said die attach pads using chip-on-board techniques.

16. The LED component of claim 1, wherein said primary optics are molded over said LED chips.

17. The LED component of claim 1, further comprising a heat sink to spread heat from said component.

18. The LED component of claim 1, further comprising secondary optics.

19. The LED component of claim 1, further comprising a reflective layer on the top surface of said circuit board.

20. The LED component of claim 19, wherein said reflective layer covers at least a portion of said die attach pads.

21. The LED component of claim 20, wherein said reflective layer extends under one or more of said primary lenses.

22. The LED component of claim 1, wherein each of said primary lenses covers all of the die attach pad(s) from its one or a subgroup of said LED chips.

23. The LED component of claim 1, wherein each of said primary lenses covers less than all of the die attach pad(s) from its one or subgroup of LED chips.

24. The LED component of claim 1, wherein said LED chips are in a linear array.

25. The LED component of claim 1, wherein said circuit board is elongated and said LED chips are in a linear array.

26. The LED component of claim 1, further comprising conductive traces running between said die attach pads.

27. The LED component of claim 1, wherein said LED chips emit more than one color of light.

28. An LED component, comprising:

a circuit board with an array of LED chips mounted on it and electrically interconnected;

a plurality of primary lenses, each of which is formed directly over a single one or a sub-group of said LED chips;

a heat sink, said circuit board mounted to said heat sink so that heat from said LED chips spreads into said heat sink.

29. The LED component of claim 28, wherein said circuit board is thermally conductive.

30. The LED component of claim 28, wherein said circuit board is electrically insulating.

31. The LED component of claim 28, wherein said circuit board comprises a layer and/or layers of material compatible with soldering.

32. The LED component of claim 28, wherein said circuit board is soldered to said heat sink.

33. The LED component of claim 28, wherein said circuit board is mechanically mounted to said heat sink.

34. The LED component of claim 28, wherein said circuit board further comprises a reflective layer.

35. A solid state lighting component, comprising:

a circuit board that is thermally conductive and electrically insulating;

a plurality of LED chips, each of which is chip-on-board mounted on a respective one of the die attach pads; and

a plurality of primary lenses, each of which is formed directly over a single one or a subgroup of said LED chips.

36. The lighting component of claim 35, wherein said circuit board comprises a dielectric with one or more thermally conductive materials.

37. The lighting component of claim 35, wherein said circuit board further comprises a conductive base plate.

38. The lighting component of claim 35, wherein said LED chips are arranged in a plurality of sub-groups.

39. The lighting component of claim 38, comprising a respective one of said primary lenses over each sub-group.

40. The lighting component of claim 35, wherein said lenses are substantially hemispheric shaped.

41. The lighting component of claim 35, wherein said LED chips are arranged in a circle on said circuit board.

42. The lighting component of claim 35, wherein said LED chips are arranged in concentric circles.

43. The lighting component of claim 35, wherein said LED chips are arranged in groups in different portion of said circuit board.

44. The lighting component of claim 35, wherein said LED chips are arranged with one group in one half of said board, and another group in the other half of said board.

45. The lighting component of claim 35, wherein said LED chips are set-back from the edge of said circuit board.

46. The lighting component of claim 35, further comprising a heat sink to spread heat from said component.

47. The lighting component of claim 35, further comprising secondary optics.

48. A method of forming an LED component, comprising:

providing a circuit board;

chip-on-board mounting LED chips on said circuit board with said LED chips electrically interconnected; and

molding primary lenses directly over each of said LED chips and sub-groups of said LED chips.

49. The method of claim 48, wherein said LED chips are arranged in sub-groups, further comprising molding primary lenses over each of said sub-groups.

50. The method of claim 48, comprising forming primary lenses over each of said LED chips.

51. The method of claim 48, further comprising forming conductive elements to interconnect said LED chips.

52. An LED component, comprising:

a circuit board;

a plurality of LED chips, mounted on said circuit board;

a primary optic over a single one or a subgroup of said LED chips; and

a secondary optic over said primary optic.

53. The LED component of claim 52, wherein said primary lens is directly over said single one or subgroup of said LED chips.

54. The LED component of claim 52, wherein said secondary lens is directly over said primary lens.

55. The LED component of claim 52, wherein said secondary optic provide for beam shaping of light from said LED chips.

56. The LED component of claim 52, wherein said secondary optics comprises conversion or scattering materials.

57. The LED component of claim 52, wherein said secondary optics are hemispheric shaped.

58. An LED component, comprising:

a circuit board;

a plurality of LED chips, mounted on said circuit board;

a plurality of primary optics, each of which is over a single one or a subgroup of said LED chips; and

a secondary optic over said primary optics.