LED PACKAGE WITH ENCAPSULANT HAVING CURVED AND PLANAR SURFACES

• US 20140027795A1
• Filed: 08/01/2013
• Published: 01/30/2014
• Est. Priority Date: 06/11/2012
• Status: Active Grant

• Current Assignee: Creeled Incorporated
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Reiherzer, Jesse, Bergmann, Michael John, Signor, Andrew, Clark, Joseph Gates
• Granted Patent: US 9,887,327 B2
• Time in Patent Office: Days
• US Class Current: 257/88
• 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 of solid state light sources on a submount, said submount having a length and width;

an encapsulant over said solid state light sources and said submount, said encapsulant having one or more planar surfaces, and a curved surface with 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 planar surfaces is aligned with an edge of said submount.

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

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

5. The emitter package of claim 1, further comprising an said encapsulant having 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 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 planar 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.

20. The emitter package of claim 1, having 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 having 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;

a conversion material layer over said LEDs; and

an encapsulant on said LEDs and said conversion material layer, said encapsulant having one or more vertical planar side surfaces and a curved upper surface.

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

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

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

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

27. The emitter package of claim 25, wherein said 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 surfaces that is at least partially oblique to at least one of said 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 LED 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, wherein said emission profile has a color temperature that varies less than 300K over a range viewing angles.

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

300 to +300 Kelvin and 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 and 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 mounted on a submount;

an encapsulant on said submount, wherein said encapsulant comprises a curved upper surface and one or more planar side surfaces having a curved edge.

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

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

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

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