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

Patent metadata

Field	Value
Publication number	US-9818919-B2
Application number	US-201213649067-A
Country	US
Kind code	B2
Filing date	Oct 10, 2012
Priority date	Jun 11, 2012
Publication date	Nov 14, 2017
Grant date	Nov 14, 2017

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.

First claim

We claim:

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.

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 ran

Assignees

• Cree Inc

Inventors

• Lowes Theodore
• Tarsa Eric J
• Heikman Sten
• Keller Bernd
• Reiherzer Jesse
• Benjamin Hormoz

Classifications

• F21V9/00

  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 title

• H10W90/756

  between a chip and a stacked lead frame, conducting package substrate or heat sink · CPC title

• H10W74/00

  Encapsulations, e.g. protective coatings · CPC title

• H10W72/884

  Die-attach connectors and bond wires · CPC title

• H10H29/8512

  Wavelength conversion materials · CPC title