EMITTER PACKAGE WITH INTEGRATED MIXING CHAMBER

• US 20130329429A1
• Filed: 05/24/2013
• Published: 12/12/2013
• Est. Priority Date: 06/11/2012
• Status: Abandoned Application

• Current Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Lowes, Theodore, Kircher, Deborah
• Application Number:
  US13/902,080
• Publication Number:
  US 20130329429A1
• Time in Patent Office: Days
• US Class Current: 362/247
• CPC Class Codes: F21K 9/62 using mixing chambers, e.g. housings with reflective walls
• 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 25/0753 the devices being arranged next to each other
• 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 2933/0091 Scattering means in or on the semiconductor body or semiconductor body package H01L33/22 takes precedence
• CPC Class Codes: H01L 33/08 with a plurality of light emitting regions, e.g. laterally discontinuous light emitting layer or photoluminescent region integrated within the semiconductor body H01L27/15 takes precedence
• CPC Class Codes: H01L 33/54 having a particular shape
• CPC Class Codes: H01L 33/60 Reflective elements

Abstract

LED packages are disclosed having encapsulants which can have at least one reflective surface. Due to the reflection of light, the encapsulant can serve as a mixing chamber and thus can produce light of a more uniform color. The encapsulant can take many different shapes, including that of a cylinder and that of a rectangular prism. Encapsulants can also include scatterers to further mix the light.

Claims

1. An emitter package, comprising:

one or more emitters on a submount;

an encapsulant over said emitters and said submount, said encapsulant having at least one reflective surface.

2. The emitter package of claim 1, wherein said encapsulant comprises a mixing chamber.

3. The emitter package of claim 1, further comprising a non-reflective primary emission surface.

4. The emitter package of claim 3, wherein said primary emission surface is a top primary emission surface.

5. The emitter package of claim 4, wherein the emission from said primary emission surface is Lambertian.

6. The emitter package of claim 1, wherein said encapsulant is overmolded.

7. The emitter package of claim 1, wherein said encapsulant has a rectangular vertical cross-section.

8. The emitter package of claim 1, wherein said encapsulant is substantially cylindrical.

9. The emitter package of claim 1, wherein said encapsulant is substantially box shaped.

10. The emitter package of claim 1, wherein said encapsulant comprises at least one side surface and a top surface.

11. The emitter package of claim 10, wherein said top surface is flat.

12. The emitter package of claim 10, wherein said top surface is shaped.

13. The emitter package of claim 10, wherein said top surface is frustospherical.

14. The emitter package of claim 10, wherein said top surface comprises a concave portion.

15. The emitter package of claim 10, wherein said top surface comprises fillets.

16. The emitter package of claim 10, wherein said at least one side surface is vertical.

17. The emitter package of claim 10, wherein said at least one side surface is planar.

18. The emitter package of claim 17, wherein said at least one side surface is parallel to a surface of at least one of said emitters.

19. The emitter package of claim 10, wherein said at least one side surface angles outward.

20. The emitter package of claim 10, wherein said at least one side surface and said submount form at least an 85°

angle.

21. The emitter package of claim 11, wherein said at least one side surface curves outward.

22. The emitter package of claim 1, wherein said encapsulant comprises a textured emission surface.

23. The emitter package of claim 1, wherein said encapsulant is substantially rod shaped.

24. The emitter package of claim 1, wherein said at least one reflective surface is a side surface.

25. The emitter package of claim 24, wherein said encapsulant comprises a transparent top surface.

26. The emitter package of claim 24, wherein said at least one reflective surface has variable reflectivity.

27. The emitter package of claim 24, wherein a lower portion of said reflective surface is more reflective than an upper portion of said reflective surface.

28. The emitter package of claim 24, comprising a first reflective side surface and a second reflective side surface;

wherein said first reflective side surface is more reflective than said second reflective side surface.

29. The emitter package of claim 1, wherein said at least one reflective surface comprises reflective white paper.

30. The emitter package of claim 1, wherein said at least one reflective surface comprises a reflective metal.

31. The emitter package of claim 1, wherein said at least one reflective surface comprises a dielectric material.

32. The emitter package of claim 1, wherein said at least one reflective surface comprises a reflective coating.

33. The emitter package of claim 1, wherein said reflective coating is uniformly distributed.

34. The emitter package of claim 1, wherein said reflective coating is non-uniformly distributed.

35. The emitter package of claim 1, comprising at least two emitters.

36. The emitter package of claim 35, wherein said emitters emit different wavelengths of light.

37. The emitter package of claim 1, comprising a red emitter, a green emitter, and a blue emitter.

38. The emitter package of claim 1, comprising a BSY emitter and a red emitter.

39. The emitter package of claim 1, further comprising a scatterer.

40. The emitter package of claim 39, wherein said scatterer comprises scattering particles.

41. The emitter package of claim 40, wherein said scattering particles are uniformly distributed in said encapsulant.

42. The emitter package of claim 40, wherein said scattering particles are non-uniformly distributed in said encapsulant.

43. The emitter package of claim 42, wherein an upper portion of said encapsulant contains less scattering particles than a lower portion of said encapsulant.

44. The emitter package of claim 42, wherein a lower portion of said encapsulatn contains less scattering particles that an upper portion of said encapsulant.

45. The emitter package of claim 39, wherein said scatterer is two-dimensional.

46. The emitter package of claim 39, wherein said scatterer is on a top surface of said encapsulant.

47. The emitter package of claim 39, wherein the height of said encapsulant is smaller than the width of said encapsulant.

48. The emitter package of claim 1, wherein the width of said one or more emitters is at least 50% the width of said encapsulant.

49. The emitter package of claim 1, wherein the width of said one or more emitters is at least 75% the width of said encapsulant.

50. The emitter package of claim 1, wherein said submount comprises a reflective top surface.

51. The emitter package of claim 1, wherein said encapsulant has a width substantially equal to a width of said submount.

52. The emitter package of claim 1, wherein said encapsulant has a width at least as wide as a width of said submount.

53. An emitter package, comprising:

one or more emitters on a submount; and

a mixing chamber over said emitters and on said submount;

wherein said mixing chamber is configured to improve the color spatial uniformity of said package.

54. The emitter package of claim 53, wherein said mixing chamber comprises an encapsulant.

55. The emitter package of claim 53, wherein said mixing chamber comprises a reflective side surface.

56. The emitter package of claim 55, wherein said reflective side surface is vertical.

57. The emitter package of claim 55, wherein said reflective side surface and said submount form at least an 85°

angle.

58. The emitter package of claim 55, wherein said at least one reflective surface has variable reflectivity.

59. The emitter package of claim 55, wherein a lower portion of said reflective surface is more reflective than an upper portion of said reflective surface.

60. The emitter package of claim 55, comprising a first reflective side surface and a second reflective side surface;

wherein said first reflective side surface is more reflective than said second reflective side surface.

61. The emitter package of claim 53, wherein said mixing chamber comprises planar side surfaces.

62. The emitter package of claim 53, wherein said mixing chamber comprises a scatterer.

63. The emitter package of claim 53, comprising at least two emitters.

64. The emitter package of claim 63, wherein said emitters emit different wavelengths of light.

65. The emitter package of claim 53, comprising a red emitter, a green emitter, and a blue emitter.

66. The emitter package of claim 53, comprising a BSY emitter and a red emitter.

67. The emitter package of claim 53, wherein said mixing chamber is rod shaped.

68. The emitter package of claim 53, wherein said encapsulant has a width substantially equal to a width of said submount.

69. The emitter package of claim 53, wherein said encapsulant has a width at least as wide as a width of said submount.

70. An emitter encapsulant, comprising:

at least one reflective surface; and

a transparent primary emission surface;

wherein said encapsulant is configured to improve the color spatial uniformity of light emission.

71. The emitter encapsulant of claim 70, wherein said at least one reflective surface is a side surface.

72. The emitter encapsulant of claim 70, wherein said encapsulant has a rectangular vertical cross-section.

73. The emitter encapsulant of claim 70, wherein said encapsulant is substantially cylindrical.

74. The emitter encapsulant of claim 70, wherein said encapsulant is substantially box shaped.

75. The emitter encapsulant of claim 70, further comprising a scatterer.

76. The emitter encapsulant of claim 75, wherein said scatterer is uniformly distributed throughout said encapsulant.

77. The emitter encapsulant of claim 75, wherein said scatterer is two-dimensional.

78. A lighting fixture, comprising:

a housing; and

at least one emitter package on said housing, said emitter package comprising an encapsulant with at least one reflective surface.