LED package with multiple element light source and encapsulant having planar surfaces

• US 9,818,919 B2
• Filed: 10/10/2012
• Issued: 11/14/2017
• Est. Priority Date: 06/11/2012
• Status: Active Grant

• Current Assignee: Creeled Incorporated
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Lowes, Theodore, Tarsa, Eric J., Heikman, Sten, Keller, Bernd, Reiherzer, Jesse, Benjamin, Hormoz
• Primary Examiner(s): Parker, Allen
• Assistant Examiner(s): Hargrove, Frederick B
• Application Number:
  US13/649,067
• Publication Number:
  US 20130328073A1
• Time in Patent Office: 1,861 Days
• Field of Search: 257 79-103, 438 29
• CPC Class Codes: F21V 9/00 Elements for modifying spectral properties, polarisation or intensity of the light emitted, e.g. filters coloured shades F21V1/00; elements characterised by cooling arrangements F21V29/502
• 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 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• 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 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 33/502 Wavelength conversion materials
• CPC Class Codes: H01L 33/504 Elements with two or more wavelength conversion materials
• CPC Class Codes: H01L 33/505 characterised by the shape, e.g. plate or foil
• CPC Class Codes: H01L 33/54 having a particular shape
• CPC Class Codes: H01L 33/60 Reflective elements

Abstract

LED packages are disclosed that are compact and efficiently emit light, and can comprise encapsulants with planar surfaces that refract and/or reflect light within the package encapsulant. The packages can comprise a submount with a plurality of LEDs, which emit different colors of light, and a blanket conversion material layer on the LEDs and the submount. The encapsulant can be on the submount, over the LEDs, and light reflected within the encapsulant will reach the conversion material to be absorbed and emitted omnidirectionally. Reflected light can now escape the encapsulant, allowing for efficient emission and a broader emission profile, when compared to conventional packages with hemispheric encapsulants or lenses. The LED package can have a higher chip area to LED package area ratio. By using an encapsulant with planar surfaces, the LED package provides unique dimensional relationships between the features and LED package ratios, enabling more flexibility with different applications.

Claims

1. An emitter package, comprising:

first and second solid state light sources on a submount;

a conversion material layer covering said first solid state light source and substantially all the top surface of said submount, wherein said conversion material layer conformally coats said first solid state light source;

an encapsulant over said conversion material layer, said encapsulant comprising two or more planar surfaces;

wherein said second solid state light source is uncovered by said conversion material layer.

2. The emitter package of claim 1, wherein said solid state light sources comprise a plurality of light emitting diodes (LEDs), at least some of which are emitting different colors of light.

3. The emitter package of claim 2, wherein at least one of said LEDs comprises a 3 dimensional geometry of the light emitting surfaces.

4. The emitter package of claim 2, wherein at least one of said LEDs comprises a geometry with entirely or partially oblique facets on one or more surfaces.

5. The emitter package of claim 2, wherein said light sources emit a white light combination of light.

6. The emitter package of claim 2, wherein at least one of said LEDs emits red light and at least one of said LEDs emits blue light.

7. The emitter package of claim 6, wherein said at least one blue emitting LED is covered by said conversion material layer.

8. The emitter package of claim 6, wherein said at least one red emitting LED is uncovered by said conversion material layer.

9. The emitter package of claim 1, wherein said solid state light sources comprise at least one solid state laser.

10. The emitter package of claim 1, wherein said encapsulant comprises a planar top surface and planar side surfaces.

11. The emitter package of claim 1, wherein said encapsulant comprises a horizontal planar surface and a vertical planar surface.

12. The emitter package of claim 1, wherein said planar surfaces cause TIR of at least some light from said solid state light sources.

13. The emitter package of claim 2, wherein at least some of said LEDs are connected in series.

14. The emitter package of claim 2, wherein at least some of said LEDs are connected in parallel.

15. The emitter package of claim 2, wherein said LEDs are connected in a series and parallel combination.

16. The emitter package of claim 1, wherein said encapsulant comprises a flat top and vertical sidewalls comprising planar surfaces.

17. The emitter package of claim 1, wherein said encapsulant shape is from the group consisting of cubic, polygon, prismatic, cylindrical, triangle, pentagon, hexagon and octagon.

18. The emitter package of claim 1, wherein said encapsulant comprises a horizontal surface and vertical surfaces numbering in the range of 3 to 12.

19. The emitter package of claim 1, comprising an emission pattern greater than 120°

full width at half maximum.

20. The emitter package of claim 1, comprising an emission pattern greater than 135 full width at half maximum, with less than 10% color variation at viewing angles between −

90 and +90 degrees.

21. The emitter package of claim 1, further comprising a polarity indicator.

22. The emitter package of claim 1, wherein at least some light is emitted from said two or more planar surfaces of said encapsulant when at least one of said solid state light sources is operating.

23. The emitter package of claim 1, comprising a submount footprint area of less than 12 mm square.

24. The emitter package of claim 1, wherein the ratio of the submount footprint to the solid state light source footprint is in the range of just over 1 to approximately 20.

25. The emitter package of claim 1, wherein said submount comprises a footprint dimension ratio of approximately 1 by 1, with said package having a corresponding footprint dimension to package height ratio in the range of approximately 0.5 to 5.

26. The emitter package of claim 1, further comprising a plurality of die attach pads on said submount.

27. The emitter package of claim 26, wherein said solid state light sources comprise a plurality of LEDs on said die attach pads in series.

28. The emitter package of claim 26, wherein said solid state light sources comprise a plurality of LEDs on said die attach pads in parallel.

29. The emitter package of claim 26, wherein said solid state light sources comprise a plurality of LED chips on said die attach pads in a series and parallel combination.

30. The emitter package of claim 1, comprising more than two solder pads.

31. The emitter package of claim 1, further comprising two or more solder pads, wherein at least one of said solder pads comprises a polarity indicator.

32. The emitter package of claim 31, further comprising die attach pads, with said solder pads on the submount face opposing said die attach pads.

33. The emitter package of claim 1, wherein said solid state light sources emit at least two different colors of light, and where said different emitting light sources are independently controllable.

34. The emitter package of claim 33, further comprising solder pads, wherein individual or groups of said different color emitting solid state light sources are connected to a dedicated set of solder pads.

35. The emitter package of claim 34, wherein the emission of said groups of different color emitting solid state light sources is controlled to a desired color point via said solder pads.

36. The emitter package of claim 34, wherein the emission of said groups of different color emitting solid state light sources is controlled via said solder pad connections to be at a specified white color point at or near the black body locus in the CIE diagram.

84. The emitter package of claim 1, wherein said two or more planar surfaces are emission surfaces.

85. The emitter package of claim 1, wherein said conversion material layer is adjacent said second solid state light source.

86. The emitter package of claim 1, wherein said conversion material layer is on at least one side surface of said second solid state light source.

87. The emitter package of claim 1, wherein said conversion material layer abuts said second solid state light source.

88. The emitter package of claim 1, wherein the height of said second solid state light source is greater than the thickness of said conversion material layer.

89. The emitter package of claim 1, wherein said second solid state light source is on an attach pad.

90. The emitter package of claim 89, wherein said conversion material layer is on a portion of said attach pad beyond the edge of said second solid state light source.

91. The emitter package of claim 89, wherein said conversion material layer is on a portion of said attach pad around said second solid state light source.

92. The emitter package of claim 89, wherein said conversion material layer is on all of said attach pad beyond the edge of said second solid state light source.

93. The emitter package of claim 89, wherein said conversion material layer covers a portion of said attach pad beyond the edge of said second solid state light source.

94. The emitter package of claim 1, wherein said conversion material layer is on a portion of the top surface of said submount around said second solid state light source.

37. An emitter package, comprising:

multiple solid state light sources on a submount;

an encapsulant on said submount, said encapsulant comprising one or more planar surfaces; and

a blanket conversion material layer over substantially all of said submount and which conformally coats a plurality of surfaces of at least some of said solid state light sources, said blanket conversion material layer between said submount and said encapsulant;

wherein at least one of said multiple solid state light sources is not covered by said blanket conversion material layer.

38. The emitter package of claim 37, said encapsulant comprising a plurality of planar surfaces, wherein at least some light is emitted from said plurality of planar surfaces of said encapsulant and widens the emission profile of said emitter package.

39. An emitter package of claim 37, wherein said solid state light sources comprise either LEDs or lasers or both.

40. The emitter package of claim 38, wherein said emission profile exceeds 120 degrees full width at half maximum (FWHM).

41. The emitter package of claim 38, wherein said emission profile exceeds 130 degrees full width at half maximum (FWHM).

42. The emitter package of claim 38, wherein said emission profile is in the range of 130 to 170 degrees full width at half maximum (FWHM).

43. The emitter package of claim 38, wherein said emission profile is in the range of 130 to 160 degrees full width at half maximum (FWHM).

44. The emitter package of claim 38, wherein said emission profile is in the range of 130 to 150 degrees full width at half maximum (FWHM).

45. The emitter package of claim 38, wherein said emission profile is approximately 150 degrees full width half maximum (FWHM).

46. The emitter package of claim 38, wherein said emission profile is greater than 135 degrees full width half maximum (FWHM), with less than 10% variation in color at −

90 to +90 degree viewing angles.

47. The emitter package of claim 37, wherein at least some light reflected within said encapsulant can escape the encapsulant.

48. The emitter package of claim 37, emitting light with variations in color temperature of less than −

300 to +300 Kelvin and viewing angles of approximately −

100 to +100 degrees.

49. The emitter package of claim 37, emitting light with variations in color temperature of less than −

400 to +400 Kelvin and viewing angles of approximately −

100 to +100 degrees.

50. The emitter package of claim 37, emitting light with variations in color temperature of less than approximately −

200 to +200 Kelvin and viewing angles of approximately −

100 to +100 degrees.

51. The emitter package of claim 37, wherein said blanket conversion material is over substantially all exposed surfaces of said submount.

52. The emitter package of claim 37, wherein said encapsulant is substantially cube shaped.

53. The emitter package of claim 37, wherein said submount comprises a footprint area of less than 12 mm square.

54. The emitter package of claim 37, wherein said footprint comprises an area of less than approximately 6 mm square.

55. The emitter package of claim 37, wherein said footprint comprises an area in the range of 1 to 4 mm square.

56. The emitter package of claim 37, wherein said footprint is approximately 2.56 mm square.

57. The emitter package of claim 37, wherein the ratio of the submount footprint to the solid state light source footprint is in the range of just over 1 to approximately 20.

58. The emitter package of claim 57, wherein said ratio is in the range of just over 1 to approximately 15.

59. The emitter package of claim 57, wherein said ratio is in the range of just over 1 to approximately 10.

60. The emitter package of claim 57, wherein said ratio is in the range of just over 1 to approximately 5.

61. The emitter package of claim 37, wherein said submount comprises a footprint dimension ratio of approximately 1 by 1, with a corresponding footprint dimension to package height ratio in the range of approximately 0.5 to 5.

62. The emitter package of claim 61, wherein said footprint dimension ratio is approximately 1 by 1, with a corresponding footprint dimension to package height ratio in the range of approximately 0.5 to 2.

63. The emitter package of claim 37, wherein said encapsulant comprises a height in the range of approximately 0.3 mm to 5 mm.

64. The emitter package of claim 63, wherein said encapsulant comprises a height in the range of approximately 0.3 mm to 2 mm.

65. The emitter package of claim 37, wherein an increased height of said encapsulant produces a wider emission pattern of said emitter package.

82. The emitter package of claim 37, wherein said conversion layer comprises a maximum thickness of 100 microns or less.

83. The emitter package of claim 37, wherein the thickness of said conversion layer is substantially uniform.

66. An emitter package, comprising:

a plurality of solid state light sources on a submount, at least two of said plurality of solid state light sources emitting different colors of light, wherein said different emitting solid state light sources are separately controllable to control the emission intensity;

a conversion material layer which conformally coats at least some of said solid state light sources and on substantially all of said submount wherein at least one of said plurality of solid state light sources is not covered by said conversion material layer; and

an encapsulant on said submount, said encapsulant comprising a plurality of planar surfaces;

wherein at least some light is emitted from said plurality of planar surfaces of said encapsulant when at least one of said solid state light sources is operating.

67. The emitter package of claim 66, wherein said light sources comprise LEDs, lasers or both.

68. The emitter package of claim 66, accepting at least two electrical signals.

69. The emitter package of claim 68, wherein each one of said two electrical signals can control the emission intensity of one of said different emitting light sources.

70. The emitter package of claim 68, comprising four or more solder pads.

71. The emitter package of claim 66, wherein said different emitting light sources comprise red emitting light sources and blue emitting light sources.

72. The emitter package of claim 66, wherein said different emitting light sources comprise red emitting light sources and violet to UV emitting light sources.

73. The emitter package of claim 71, wherein said conversion material layer covers said blue emitting light sources.

74. The emitter package of claim 73, wherein said conversion material layer converts at least some of said blue light to yellow light.

75. The emitter package of claim 74, wherein said conversion material layer does not cover said red emitting LEDs.

76. The emitter package of claim 75, emitting a white light combination of red, blue and yellow light.

77. The emitter package of claim 72, wherein said conversion material layer converts at least some of said violet to UV light to blue and/or yellow light.

78. The emitter package of claim 77, wherein said conversion material layer does not cover said red emitting LEDs.

79. The emitter package of claim 78, emitting a white light combination of red, blue and yellow light.

80. An emitter package, comprising:

multiple solid state light sources on a submount;

an encapsulant on said submount, said encapsulant comprising a plurality of planar surfaces; and

a blanket conversion material layer over substantially all of said submount and which conformally coats at least some of said solid state light sources, wherein at least one of said multiple solid state light sources is not covered by said blanket conversion material layer, said blanket conversion material layer between said submount and said encapsulant, wherein said blanket conversion material layer comprises a maximum thickness of 100 microns or less;

wherein at least some light is emitted from said plurality of planar surfaces of said encapsulant when at least one of said solid state light sources is operating.

81. A solid state luminaire, comprising:

a solid state light source comprising a plurality of emitter packages, one or more of said packages comprising;

first and second solid state light sources on a submount;

a blanket conversion material layer on substantially all of said submount and which conformally coats said first solid state light source; and

an encapsulant over said blanket conversion material layer, said encapsulant comprising two or more planar surfaces;

wherein said second solid state light source is uncovered by said blanket conversion material layer.