LED PACKAGE WITH INCREASED FEATURE SIZES

• US 20100252851A1
• Filed: 04/09/2010
• Published: 10/07/2010
• Est. Priority Date: 10/31/2007
• Status: Active Grant

• Current Assignee: Creeled Incorporated
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Collins, Brian, Hussell, Christopher, Salter, Amber, Keller, Bernd, Tarsa, Eric, Andrews, Peter, Edmond, John, Emerson, David, Bergmann, Michael
• Granted Patent: US 8,866,169 B2
• Time in Patent Office: Days
• US Class Current: 257/98
• CPC Class Codes: H01L 2224/48091 Arched
• 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 2924/01019 Potassium [K]
• CPC Class Codes: H01L 2924/01087 Francium [Fr]
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/486 adapted for surface mounting
• CPC Class Codes: H01L 33/54 having a particular shape
• CPC Class Codes: H01L 33/58 Optical field-shaping elements
• CPC Class Codes: H01L 33/62 Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls
• CPC Class Codes: H01L 33/641 characterized by the materials

Abstract

A light emitter package having increased feature sizes for improved luminous flux and efficacy. An emitter chip is disposed on a submount with a lens that covers the emitter chip. In some cases, the ratio of the width of the light emitter chip to the width of said lens in a given direction is 0.5 or greater. Increased feature sizes allow the package to emit light more efficiently. Some packages include submounts having dimensions greater than 3.5 mm square used in conjunction with larger emitter chips. Materials having higher thermal conductivities are used to fabricate the submounts, providing the package with better thermal management.

Claims

1. A light emitter package, comprising:

a submount;

a light emitter chip mounted on said submount;

a lens over said light emitter chip, the ratio of the width of said light emitter chip to the width of said lens in a given direction being 0.5 or greater.

2. The light emitter package of claim 1, wherein the current density in said light emitter chip is lower compared to a light emitter chip with a smaller width.

3. The light emitter package of claim 1, further comprising a conversion material proximate to said light emitter chip, said conversion material comprising phosphor particles having a D₅₀ particle size of greater than 10 microns.

4. The light emitter package of claim 3, further comprising scattering particles.

5. The light emitter package of claim 4, wherein said scattering particles are substantially the same size as said phosphor particles.

6. The light emitter package of claim 1, said light emitter package emitting higher light output power compared to a light emitter package having a smaller light emitter chip with similar features.

7. The light emitter package of claim 1, further comprising chip alignment features on said submount.

8. The light emitter package of claim 1, further comprising an electrostatic discharge (ESD) protection device.

9. The light emitter package of claim 1, said submount comprising aluminum nitride (AlN).

10. The light emitter package of claim 1, said light emitter chip emitting light having an average wavelength of approximately 430-460 nm.

11. The light emitter package of claim 1, said submount having dimensions of approximately 3.5 mm square to 5 mm square.

12. The light emitter package of claim 1, said light emitter chip having dimensions of approximately 0.7 mm square to 3 mm square.

13. The light emitter package of claim 1, said light emitter chip being approximately 1.4 mm square, said submount being approximately 3 mm square.

14. The light emitter package of claim 13, said package exhibiting an output power 150 lumens/watt or higher during operation.

15. The light emitter package of claim 1, said light emitter chip being approximately 1.75 mm square, said submount being approximately 5 mm square.

16. The light emitter package of claim 1, said light emitter chip being approximately 2 mm square, said submount being approximately 5 mm square.

17. The light emitter package of claim 16, said package exhibiting higher than 150 lumens/watt during operation.

18. The light emitter package of claim 1, said light emitter chip being approximately 3 mm square, said submount being approximately 5 mm square.

19. The light emitter package of claim 18, said package exhibiting higher than 150 lumens/watt during operation.

20. The light emitter package of claim 1, said light emitter chip comprising a light emitting diode (LED) chip.

21. The light emitter package of claim 1, wherein said light emitter chip covers more than 10% of the surface area of said submount.

22. The light emitter package of claim 1, wherein said light emitter chip covers more than 15% of the surface area of said submount.

23. A light emitting diode (LED) package, comprising:

a submount comprising a top and bottom surface;

a plurality of top electrically and thermally conductive elements on said top surface of said submount;

an LED chip on one of said top elements, said electrically conductive elements arranged to spread heat from said LED chip across the majority of said submount top surface;

a bottom thermally conductive element on said bottom surface not in electrical contact with said top elements and arranged to conduct heat from said submount; and

a lens over said LED chip;

wherein the ratio of the width of said LED chip to the width of said lens in a given direction is 0.5 or greater.

24. The LED package of claim 23, wherein said LED chip covers more than 10% of the surface area of said submount.

25. The LED package of claim 23, wherein said LED chip covers more than 15% of the surface area of said submount.

26. The LED package of claim 23, further comprising a conversion material proximate to said LED chip, said conversion material comprising phosphor particles having a D₅₀ particle size of greater than 10 microns.

27. The LED package of claim 26, further comprising scattering particles.

28. The LED package of claim 27, wherein said scattering particles are substantially the same size as said phosphor particles.

29. The LED package of claim 23, said LED package emitting higher light output power compared to an LED package having a smaller LED chip with similar features.

30. The LED package of claim 23, further comprising chip alignment features on said submount.

31. The LED package of claim 23, further comprising an electrostatic discharge (ESD) protection device.

32. The LED package of claim 23, said submount comprising aluminum nitride (AlN).

33. The LED package of claim 23, said LED chip emitting light having an average wavelength of approximately 430-460 nm.

34. The LED package of claim 23, said submount having dimensions of approximately 3.5 mm square to 5 mm square.

35. The LED package of claim 23, said LED chip having dimensions of approximately 0.7 mm square to 3 mm square.

36. The LED package of claim 23, said LED chip being approximately 1.4 mm square, said submount being approximately 3 mm square.

37. The LED package of claim 36, said LED package exhibiting an output power of 150 lumens/watt or greater during operation.

38. The LED package of claim 23, said LED chip being approximately 1.75 mm square, said submount being approximately 5 mm square.

39. The LED package of claim 23, said LED chip being approximately 2 mm square, said submount being approximately 5 mm square.

40. The LED package of claim 39, said LED package exhibiting an output power of 150 lumens/watt or greater during operation.

41. The LED package of claim 23, wherein said top elements cover more that 50% of said submount top surface.

42. The LED package of claim 23, further comprising first and second mounting pads on said bottom surface and a plurality of conductive vias running though said submount.

43. The LED package of claim 23, further comprising a solder mask covering at least a portion of said top elements.

44. The LED package of claim 23, further comprising a protective layer between the edge of said lens and the edge of said top surface, said protective layer covering said submount top surface and said top elements.

45. A light emitter package, comprising:

a submount comprising aluminum nitride (AlN);

a light emitter chip on said submount, said light emitter emitting light having an approximate average wavelength in the range of 430-460 nm; and

a lens on said light emitter chip;

wherein the ratio of the width of said light emitter chip to the width of said lens in a given direction is 0.5 or greater.

46. A light emitter package, comprising:

a single light emitting diode (LED) chip;

a submount having dimensions of 3.5 mm square or larger;

a molded lens over said LED chip on said submount.

47. The light emitter package of claim 46, said submount having dimensions of approximately 5 mm square, said LED chip having dimensions of approximately 2 mm square, and said molded lens having a diameter of approximately 4.52 mm.

48. The light emitter package of claim 46, said submount comprising aluminum nitride.

49. The light emitter package of claim 46, said package outputting white light at an efficacy of 150 lm/W or more within a 7-step MacAdam ellipse along the black body curve when operated with a drive current of 350 mA.

50. The light emitter package of claim 46, said package outputting 160 lm or more at an efficacy of 160 lm/W or more when operated with a drive current.

51. The light emitter package of claim 50, said drive current being approximately 350 mA.

52. The light emitter package of claim 46, said submount having dimensions of 4 mm square or larger

53. The light emitter package of claim 52, said package outputting 750 lm or more at an efficacy of 110 lm/W or more when operated with a drive current.

54. The light emitter package of claim 53, said drive current being approximately 2 A.

55. A light emitter package, comprising:

a light emitter chip;

a submount comprising a material having a thermal conductivity of 30 W/m·

K or higher; and

a molded lens over said emitter on said submount.

56. The light emitter package of claim 55, said submount having a thermal conductivity of 50 W/m·

K or higher.

57. The light emitter package of claim 55, said submount having a thermal conductivity of 100 W/m·

K or higher.

58. The light emitter package of claim 55, said submount having a thermal conductivity of 120 W/m·

K or higher.

59. The light emitter package of claim 55, said submount comprising aluminum nitride.

60. The light emitter package of claim 55, further comprising a conversion material proximate to said light emitter chip, said conversion material comprising phosphor particles having a D₅₀ particle size of greater than 10 microns.

61. The light emitter package of claim 55, further comprising chip alignment features on said submount.

62. The light emitter package of claim 55, further comprising an electrostatic discharge (ESD) protection device.

63. The light emitter package of claim 55, said light emitter chip emitting light having an average wavelength of approximately 430-460 nm.

64. The light emitter package of claim 55, said submount having dimensions of approximately 3.5 mm square to 5 mm square.

65. The light emitter package of claim 55, said light emitter chip having dimensions of approximately 0.7 mm square to 3 mm square.

66. The light emitter package of claim 55, said light emitter chip being approximately 1.75 mm square, said submount being approximately 5 mm square.

67. The light emitter package of claim 55, said light emitter chip being approximately 2 mm square, said submount being approximately 5 mm square.

68. The light emitter package of claim 67, said package exhibiting higher than 150 lumens/watt during operation.

69. The light emitter package of claim 55, said light emitter chip being approximately 3 mm square, said submount being approximately 5 mm square.

70. The light emitter package of claim 69, said package exhibiting higher than 150 lumens/watt during operation.