LED package with encapsulant having curved and planar surfaces

• US 9,887,327 B2
• Filed: 08/01/2013
• Issued: 02/06/2018
• Est. Priority Date: 06/11/2012
• Status: Active Grant

• Current Assignee: Creeled Incorporated
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Reiherzer, Jesse, Signor, Andrew, Clark, Joseph Gates, Bergmann, Michael John
• Primary Examiner(s): Dang, Trung Q
• Assistant Examiner(s): Hargrove, Frederick B
• Application Number:
  US13/957,290
• Publication Number:
  US 20140027795A1
• Time in Patent Office: 1,650 Days
• Field of Search: 257 79-103
• 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 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 33/486 adapted for surface mounting
• CPC Class Codes: H01L 33/505 characterised by the shape, e.g. plate or foil
• CPC Class Codes: H01L 33/508 having a non-uniform spatial arrangement or non-uniform concentration, e.g. patterned wavelength conversion layer, wavelength conversion layer with a concentration gradient of the wavelength conversion material
• CPC Class Codes: H01L 33/54 having a particular shape
• CPC Class Codes: H01L 33/58 Optical field-shaping elements

Abstract

LED packages are disclosed that are compact and efficiently emit light, and can comprise encapsulants with curved and planar surfaces. The packages can comprise a submount with a one or a plurality of LEDs, and in those with a plurality of LEDs each of the LEDs can emit the same or different wavelengths of light than the others. A blanket conversion material layer can be included on at least some of the LEDs and the submount. The encapsulant can be on the submount, over at least some of the LEDs, with each of the planar surfaces being vertical and aligned with one of the edges of the submount. The encapsulant can also have a upper curved surface with a relatively large radius of curvature, with the combination of curved and planar surfaces resulting in efficient emission of light with a relatively narrow emission profile.

Claims

1. An emitter package, comprising:

one or more solid state light sources on a submount, said submount comprising a plurality of edges such that said submount comprises a length and width;

an encapsulant over said solid state light sources and said submount, said encapsulant comprising a plurality of substantially planar side surfaces, one of said substantially planar side surfaces along each edge of said submount, and a convex curved surface between each pair of adjacent substantially planar side surfaces, said convex curved surface comprising a radius of curvature greater than half of said submount length and/or width.

2. The emitter package of claim 1, wherein each of said substantially planar side surfaces is aligned with an edge of said submount.

3. The emitter package of claim 1, wherein said substantially planar side surfaces are vertical.

4. The emitter package of claim 1, wherein said substantially planar side surfaces are orthogonal to the top surface of said submount.

5. The emitter package of claim 1, wherein said encapsulant comprises a conversion material occupying less than all of said encapsulant.

6. The emitter package of claim 5, wherein said conversion material occupies less than 80 percent of said encapsulant.

7. The emitter package of claim 5, wherein said conversion material occupies less than 50 percent of said encapsulant.

8. The emitter package of claim 5, wherein said conversion material occupies less than 25 percent of said encapsulant.

9. The emitter package of claim 1, wherein said conversion material occupies less than 10 percent of said encapsulant.

10. The emitter package of claim 1, wherein said conversion material is in a lower portion of said encapsulant.

11. The emitter package of claim 10, wherein said encapsulant comprises an upper portion without conversion material.

12. The emitter package of claim 10, wherein said conversion material is in the lower half of said encapsulant.

13. The emitter package of claim 10, wherein said conversion material is in the lower one fourth of said encapsulant.

14. The emitter package of claim 1, wherein said solid state light sources comprise one light emitting diode.

15. 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.

16. The emitter package of claim 15, wherein at least one of said LEDs has a geometry with entirely or partially oblique facets on one or more surfaces.

17. The emitter package of claim 15, wherein said light sources emit a white light combination of light.

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

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

full width at half maximum (FWHM).

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

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

22. An emitter package, comprising:

one or more light emitting diodes (LEDs) on a submount;

a conversion material layer over said LEDs; and

an encapsulant on said LEDs and said conversion material layer, said encapsulant comprising one or more vertical planar side surfaces and a hemispheric upper surface, a convex curved surface between each pair of adjacent vertical planar side surfaces and over said LEDs, wherein said vertical planar side surfaces at least partially truncate said convex curved surface.

23. The emitter package of claim 22, wherein at least one of said vertical planar side surfaces has a curved edge.

24. The emitter package of claim 22, wherein at least one of said vertical planar surfaces has a semi-circular shape.

25. The emitter package of claim 22, further comprising a submount, said one or more LEDs and said encapsulant on said submount.

26. The emitter package of claim 25, wherein at least one of said vertical planar side surfaces is aligned with an edge of said submount.

27. The emitter package of claim 25, wherein said vertical planar side surfaces are orthogonal to the top surface of said submount.

28. The emitter package of claim 22, wherein at least one of said LEDs has a side surface that is at least partially oblique to at least one of said vertical planar side surfaces.

29. The emitter package of claim 22, wherein at least one of said LEDs comprises a textured surface.

30. The emitter package of claim 22, wherein at least one of said LEDs comprises a sapphire substrate.

31. The emitter package of claim 22, wherein said emission profile less than 120 degrees full width at half maximum (FWHM).

32. The emitter package of claim 22, comprising an emission profile has a color temperature that varies less than 300K over a range of viewing angles.

33. The emitter package of claim 22, emitting light with variations in color temperature of less than −

300 to +300 Kelvin at viewing angles of approximately −

100 to +100 degrees.

34. The emitter package of claim 22, emitting light with variations in color temperature of less than approximately −

200 to +200 Kelvin at viewing angles of approximately −

100 to +100 degrees.

35. The emitter package of claim 25, wherein said submount has a square footprint.

36. The emitter package of claim 35, wherein said submount has a footprint area of less than 12 mm square.

37. The emitter package of claim 35, wherein said submount has a footprint area in the range of 1 to 4 mm square.

38. An emitter package, comprising:

one or more LEDs on a submount, said submount comprising a plurality of edges;

an encapsulant on said submount, wherein said encapsulant comprises a plurality of substantially planar side surfaces, one of said substantially planar side surfaces along each edge of said submount and a convex curved surface between each pair of adjacent substantially planar side surfaces and between opposing substantially planar side surfaces and over said one or more LEDs, wherein said substantially planar side surfaces at least partially truncate said convex curved surface.

39. The emitter package of claim 38, wherein each of said substantially planar side surfaces are aligned with an edge of said submount.

40. The emitter package of claim 38, wherein at least one of said substantially planar side surfaces is vertical.

41. The emitter package of claim 38, wherein at least one of said substantially planar side surfaces is orthogonal to the top surface of said submount.

42. The emitter package of claim 38, wherein said convex curved surface comprises a radius of curvature greater than half of said submount length and/or width.

43. An encapsulant, comprising:

a body shaped to fit within a rectangular footprint, said body comprising a plurality of substantially planar side surfaces and a convex curved surface between each pair of adjacent substantially planar side surfaces and between opposing substantially planar side surfaces;

wherein said substantially planar side surfaces at least partially truncate said convex curved surface and wherein said convex curved surface comprises a continuous curved surface.