LED package with encapsulant having planar surfaces

• US 9,048,396 B2
• Filed: 10/10/2012
• Issued: 06/02/2015
• 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): Alavi, Ali
• Application Number:
  US13/649,052
• Publication Number:
  US 20130329425A1
• Time in Patent Office: 965 Days
• Field of Search: 362/231, 362/311.02, 362/311.03, 362/84, 257/E21.85, 257/676, 438/25, 438/26, 438/106
• US Class Current: 1/1
• 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 one or more LEDs, 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, where it is 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. In certain embodiments, the LED package provides a higher chip area to LED package area ratio. By using an encapsulant with planar surfaces, the LED package can provide unique dimensional relationships between the various features and the LED package ratios, enabling more flexibility with different applications.

Claims

1. A lighting package, comprising:

a solid state light source on a submount;

a wavelength conversion material layer covering said solid state light source and the top surface of said submount;

an encapsulant over said conversion material layer, said encapsulant having one or more planar surfaces, wherein said planar surfaces cause total internal reflection (TIR) of at least some light from said light source.

2. The lighting package of claim 1, wherein said solid state light source comprises one or more light emitting diodes (LEDs).

3. The lighting package of claim 1, wherein said solid state light source comprises one or more solid state lasers.

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

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

6. The lighting package of claim 1, further comprising two or more solder pads on the backside of said submount.

7. The lighting package of claim 1, wherein said light source comprises a single LED.

8. The lighting package of claim 1, wherein said light source comprising multiple LED chips.

9. The lighting package of claim 8, wherein said LED chips are connected in series.

10. The lighting package of claim 8, wherein at least some of said LED chips are connected in parallel.

11. The lighting package of claim 8, wherein said LED chips are connected in a series and parallel combination.

12. The lighting package of claim 1, wherein said encapsulant comprises a flat top and vertical sidewalls with planar surfaces.

13. The lighting package of claim 1, wherein said encapsulant shape is from the group comprising cubic, prismatic, cylindrical, triangle, pentagon, hexagon and octagon.

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

15. The lighting package of claim 1, comprising an emission pattern greater than 120°

full width at half maximum.

16. The lighting package of claim 1, wherein said one or more planar surfaces comprise features having a root mean square (RMS) size greater than the wavelength of light emitting from said LED light source.

17. The lighting package of claim 1, further comprising a polarity indicator.

18. The lighting package of claim 17, wherein the polarity indicator is on the top or bottom surface of said submount, or both.

19. The lighting package of claim 1, having an emission profile that is wider than a package with identical features aside from an encapsulant not having planar surfaces.

20. The lighting package of claim 1, having a submount footprint area of less than 12 mm square.

21. The lighting package of claim 1, wherein the ratio of the footprint of said submount to the footprint of said one or more LEDs is in the range of just over 1 to approximately 20.

22. The lighting package of claim 1, wherein the ratio of the footprint of said submount to the footprint of said one or more LEDs is in the range of about 2.5.

23. The lighting package of claim 1, wherein said submount has a footprint ratio of approximately 1 by 1, with a corresponding height ratio in the range of approximately 0.5 to 5.

24. The lighting package of claim 1, wherein said light source comprises one or more LEDs, further comprising a plurality of die attach pads on said submount and below said encapsulant, said one or more LEDs mounted to said die attach pads.

25. The lighting package of claim 24, wherein said one or more LEDs comprise a plurality of LEDs chip mounted to said die attach pads in series.

26. The lighting package of claim 24, wherein said LEDs chip are mounted to said die attach pads in parallel.

27. The lighting package of claim 24, wherein said LED light source comprises a plurality of LED chips mounted to said die attach pads in a series and parallel combination.

28. The lighting package of claim 1, wherein said solid state light source comprises a violet to UV emitting light source.

29. The lighting package of claim 28, wherein said wavelength conversion material layer converts at least some of said violet to UV light to blue and/or yellow light.

30. The lighting package of claim 28, wherein said wavelength conversion material layer comprises a combination of red, green and blue phosphors.

31. An emitter package, comprising:

a solid state light source on a submount;

a encapsulant on said submount, said encapsulant having one or more planar surfaces; and

a wavelength conversion material layer covering said solid state light source and the top surface of said submount;

a polarity indicator on the bottom surface of said submount.

32. The emitter package of claim 31, wherein said solid state light source is selected from the group consisting of an LED and a laser.

33. The emitter package of claim 32, wherein said polarity indicators are visible by cameras in solid state manufacturing equipment.

34. The emitter package of claim 32, further comprising one or more contact pads on said submount.

35. The emitter package of claim 32, wherein said polarity indicator is in or on one of said contact pads.

36. The emitter package of claim 32, wherein said polarity indicator near the middle of one of the edges of one of said contact pads.

37. The emitter package of claim 32, wherein said polarity indictor is at the corner of one of said contact pads.

38. The emitter package of claim 32, wherein said polarity indicator comprises a notch.

39. The emitter package of claim 32, wherein said notch has a shape from the group comprising V-shaped, U-shaped, I-shaped, W-shaped, square shaped, rectangular shaped, plus shaped, minus shaped, and star shaped.

40. The emitter package of claim 32, wherein said polarity indicator is arranged such that it is visible through holes in LED carrier tape.

41. The emitter package of claim 32, further comprising one or more die attach pads.

42. The emitter package of claim 41, wherein said polarity indicator is in or one of said die attach pads.

43. The emitter package of claim 41, wherein said polarity indictor is along the edge of one of said die attach pads.

44. The emitter package of claim 41, wherein said polarity indicator comprises a notch.

45. The emitter package of claim 41, wherein said polarity indicator has a shape from the group comprising V-shaped, U-shaped, I-shaped, W-shaped, square shaped, rectangular shaped, plus shaped, minus shaped, and star shaped.

46. An emitter package, comprising:

a solid state light source on a submount;

an encapsulant on said submount, said encapsulant having one or more planar surfaces, wherein said package emits an emission profile that is wider than a package with identical features aside from a encapsulant not having planar surfaces.

47. The emitter package of claim 46, wherein said solid state light source is selected from the group consisting of an LED and a laser.

48. The emitter package of claim 47, wherein said encapsulant is cube shaped.

49. The emitter package of claim 47, wherein said package emits an emission profile that is wider than a similar package with a hemispheric encapsulant.

50. The emitter package of claim 47, wherein said emission profile exceeds 120 degrees full width at half maximum (FWHM).

51. The emitter package of claim 47, wherein said emission profile exceeds 130 degrees full width at half maximum (FWHM).

52. The emitter package of claim 47, wherein said emission profile is in the range of 130 to 170 degrees full width at half maximum (FWMH).

53. The emitter package of claim 47, wherein said emission profile is in the range of 130 to 160 degrees full width at half maximum (FWMH).

54. The emitter package of claim 47, wherein said emission profile is in the range of 130 to 150 degrees full width at half maximum (FWMH).

55. The emitter package of claim 47, wherein said emission profile is approximately 150 degrees full width half maximum (FWHM).

56. The emitter package of claim 47, emitting light with substantially the same efficiency as a similar package with an encapsulant not having planar surfaces.

57. The emitter package of claim 47, emitting light with variations in color temperature of less than −

300 to +300 Kelvin in a viewing angle range of approximately −

100 to +100 degrees.

58. The emitter package of claim 47, emitting light with variations in color temperature of less than −

400 to +400 Kelvin and in a viewing angle range of approximately −

100 to +100 degrees.

59. The emitter package of claim 47, emitting light with variations in color temperature of less than approximately −

200 to +200 Kelvin and in a viewing angle range of approximately −

100 to +100 degrees.

60. The emitter package of claim 47, further comprising a blanket conversion material on said submount and below said encapsulant.

61. An emitter package, comprising:

a solid state light source on a submount;

an encapsulant on said submount, said encapsulant having one or more planar surfaces,

a wavelength conversion material layer covering said solid state light source and the top surface of said submount;

wherein said submount has a footprint area of less than 12 mm square per 1 mm square light source area, wherein said encapsulant is cube shaped.

62. The emitter package of claim 61, wherein said solid state light source is selected from the group consisting of an LED and a laser.

63. The emitter package of claim 62, further comprising a blanket conversion material on said submount and below said encapsulant.

64. The emitter package of claim 62, wherein said footprint has an area of less than approximately 9 mm square per 1 mm square light source area.

65. The emitter package of claim 62, wherein said footprint has an area of less than approximately 6 mm square per 1 mm square light source area.

66. The emitter package of claim 62, wherein said footprint has an area of less than approximately 4 mm square per 1 mm square light source area.

67. The emitter package of claim 62, wherein said footprint has an area in the range of 1 to 4 mm square per 1 mm square light source area.

68. The emitter package of claim 62, wherein said footprint is approximately 2.56 mm square.

69. An emitter package, comprising:

one or more solid state light sources on a submount; and

an encapsulant on said submount, said encapsulant having one or more planar surfaces,

a wavelength conversion material layer covering said one or more solid state light sources and the top surface of said submount;

wherein the ratio of the footprint of said submount to the footprint of said one or more solid state light sources is in the range of just over 1 to approximately 20.

70. The emitter package of claim 69, wherein said one or more solid state light sources are selected from the group consisting of LEDs, lasers and a combination thereof.

71. The emitter package of claim 70, wherein said ratio is in the range of just over 1 to approximately 3.

72. The emitter package of claim 70, wherein said ratio is in the range of just over 1 to approximately 2.

73. The emitter package of claim 70, wherein said ratio is in the range of just over 1 to approximately 15.

74. The emitter package of claim 70, wherein said ratio is in the range of just over 1 to approximately 10.

75. The emitter package of claim 70, wherein said ratio is in the range of just over 1 to approximately 5.

76. An emitter package, comprising:

one or more solid state light sources on a submount; and

a transparent encapsulant on said submount, said encapsulant having one or more planar surfaces,

a wavelength conversion material layer covering said solid state light source and the top surface of said submount;

wherein said submount has a footprint ratio of approximately 1 by 1, with a corresponding height ratio in the range of approximately 0.5 to 5.

77. The emitter package of claim 76, wherein said one or more solid state light sources are selected from the group consisting of LEDs, lasers and a combination thereof.

78. The emitter package of claim 77, wherein said encapsulant has a height in the range of approximately 0.3 mm to 5 mm.

79. The emitter package of claim 77, emitting a wider emission pattern with higher encapsulants.

80. The emitter package of claim 77, wherein said footprint ratio is approximately 1 by 1, with a corresponding height ratio in the range of approximately 0.5 to 2.

81. The emitter package of claim 77, wherein said footprint ratio is approximately 1 by 1, with a corresponding height ratio in the range of approximately 0.5 to 1.5.

82. The emitter package of claim 77, wherein said footprint to height ratios are approximately of 1 by 1 by approximately 1.5 or greater.

83. The emitter package of claim 77, wherein said footprint to height ratios are approximately of 1 by 1 by approximately 2 or greater.

84. The emitter package of claim 77, wherein said footprint to height ratios are approximately of 1 by 1 by approximately 3 or greater.

85. The emitter package of claim 77, wherein said encapsulant has a height in the range of approximately 0.3 mm to 5 mm.

86. The emitter package of claim 77, wherein said encapsulant has a height in the range of approximately 0.3 mm to 2 mm.

87. A solid state luminaire, comprising:

a solid state light source with one or more light emitting diode (LED) packages, comprising;

an LED light source on a submount;

a blanket conversion material layer on said submount;

an encapsulant over said conversion material layer, said encapsulant having one or more planar surfaces, wherein said planar surfaces cause total internal reflection (TIR) of at least some light from said light source.

88. The luminaire of claim 87, comprising a light bulb.

89. The luminaire of claim 87, comprising a troffer.

90. The luminaire of claim 87, comprising a street lamp.

91. The luminaire of claim 87, wherein said encapsulant is cube shaped.