Uniform emission LED package

• US 20070228387A1
• Filed: 04/04/2006
• Published: 10/04/2007
• Est. Priority Date: 04/04/2006
• Status: Active Grant

• Current Assignee: Creeled Incorporated
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Negley, Gerald, Becerra, Maryanne, Leung, Michael, Tarsa, Eric, Andrews, Peter
• Granted Patent: US 8,969,908 B2
• Time in Patent Office: Days
• US Class Current: 257/79
• 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 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2933/0033 relating to semiconductor body packages
• CPC Class Codes: H01L 2933/005 relating to encapsulations
• 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 33/507 the elements being in intimate contact with parts other than the semiconductor body or integrated with parts other than the semiconductor body
• CPC Class Codes: H01L 33/54 having a particular shape
• CPC Class Codes: H01L 33/58 Optical field-shaping elements

Abstract

An emitter package comprising a light emitting diode (LED) mounted to the surface of a submount with the surface having a first meniscus forming feature around the LED. A matrix encapsulant is included on the surface and covering the LED. The outer edge of the matrix encapsulant adjacent the surface is defined by the meniscus forming feature and the encapsulant forms a substantially dome-shaped covering over said LED. A method for manufacturing an LED package by providing a body with a surface having a first meniscus holding feature. An LED is mounted to the surface with the meniscus holding feature around the LED. A liquid matrix encapsulant is introduced over the LED and the surface, the first meniscus holding feature holding the liquid matrix encapsulant in a dome-shape over the LED. The matrix encapsulant is then cured.

Claims

1. An emitter package, comprising:

a submount,

a solid state emitter mounted to a surface of said submount, said submount comprising a first meniscus forming feature around said solid state emitter;

an encapsulant matrix on said surface of said submount, and covering said solid state emitter, said matrix encapsulant forming a dome-shape over said solid state emitter, the size and shape of said encapsulant matrix at least partially defined by the width and shape of said meniscus forming feature.

2. The package of claim 1, wherein said first meniscus forming feature has a width around said emitter to hold said encapsulant matrix in said dome-shape over said emitter by a meniscus formed between said encapsulant matrix and said meniscus forming feature.

3. The package of claim 1, wherein said solid state emitter comprises a light emitting diode.

4. The package of claim 1, wherein said first meniscus forming feature comprises a physical transition that creates a meniscus when a liquid contacts it.

5. The package of claim 1, wherein said first meniscus forming feature comprises a physical feature from the group an edge, corner, ledge and trench.

6. The package of claim 1, wherein said first meniscus forming feature comprises the edge of said surface.

7. The package of claim 1, wherein said first meniscus forming feature has a circular, square, rectangular or octagonal shape around said emitter.

8. The package of claim 1, wherein said first meniscus forming feature has a square shape with notches at the corners.

9. The package of claim 1, wherein said encapsulant matrix comprises a conversion material.

10. The package of claim 1, further comprising a second meniscus forming feature around said first meniscus forming feature.

11. The package of claim 1, further comprising an intermediate encapsulant over said encapsulant matrix in a dome-shape, the size and shape of said intermediate encapsulant at least partially defined by the size and shape of said second meniscus forming feature.

12. The package of claim 11, wherein said second meniscus forming feature comprises a physical transition that creates a meniscus when a liquid contacts it.

13. The package of claim 11, wherein said matrix encapsulant comprises a conversion material, and wherein said intermediate encapsulant is transparent to the wavelength of light emitter by said emitter and said conversion material, and wherein said intermediate encapsulant has a higher index of refraction than said matrix encapsulant.

14. The package of claim 11, wherein said submount comprises an upper portion and a lower portion, said upper portion having a width smaller than the width of said lower portion, wherein said first meniscus holding feature being the edge of said upper portion, and said second meniscus holding feature being the edge of said lower portion.

15. The package of claim 1, wherein said submount is mounted to a printed circuit board.

16. The package of claim 15, comprising a secondary encapsulant covering said matrix encapsulant and said submount.

17. The package of claim 16, wherein said matrix encapsulant comprises a conversion material, and wherein said secondary encapsulant is transparent to the wavelength of light emitter by said emitter and said conversion material, and wherein said secondary encapsulant has a higher index of refraction than said matrix encapsulant.

18. A method for manufacturing an emitter package, comprising:

providing a body with a surface having a first meniscus holding feature;

introducing a liquid encapsulant matrix over said emitter and said surface, said first meniscus holding feature holding said liquid encapsulant matrix in a dome-shape over said emitter; and

curing said encapsulant matrix.

19. The method of claim 18, wherein said body comprises a solid state emitter.

20. The method of claim 19, wherein said first meniscus holding feature comprises the top edge of said solid state emitter.

21. The method of claim 18, wherein said body comprises a submount, said method comprising the further step of mounting a solid state emitter to said submount with said meniscus holding feature around said emitter.

22. The method of claim 18, wherein the viscosity of said liquid matrix encapsulant and the width of said first meniscus holding feature around said solid state emitter provides a meniscus at said meniscus holding feature holding said liquid matrix encapsulant in said dome-shape.

23. The method of claim 19, further comprising a second meniscus holding feature around said first meniscus holding feature, and further comprising introducing an intermediate/secondary encapsulation material over said cured matrix encapsulant, the second meniscus holding feature influencing the width and shape of said intermediate/secondary encapsulant.

24. The method of claim 21, further comprising curing said intermediate/secondary encapsulant.

25. The method of claim 18, further comprising mounting said body to a printed circuit board (PCB).

26. An emitter package, comprising:

a solid state emitter mounted to the surface of a body, said surface having a first meniscus forming feature around said emitter;

an encapsulant on said surface and covering said solid state emitter, the outer edge of said encapsulant adjacent said surface defined by said meniscus forming feature, said encapsulant forming a substantially dome-shaped covering over said emitter.

27. The package of claim 26, wherein said meniscus forming feature has a width around said emitter to hold a liquid in a dome-shape over said emitter by a meniscus formed between said liquid and said meniscus forming feature.

28. The package of claim 26, wherein said solid state emitter comprises a light emitting diode.

29. The package of claim 26, wherein said encapsulant further comprises a conversion material.

30. The package of claim 26, wherein said first meniscus forming feature comprises a physical transition that creates a meniscus when a liquid contacts it.

31. The package of claim 26, wherein said first meniscus forming feature comprises the edge of said surface.

32. The package of claim 26, further comprising a second meniscus forming feature around said first meniscus forming feature.

33. The package of claim 26, further comprising an intermediate encapsulant over said matrix encapsulant in a dome-shape, the outer edge of said intermediate encapsulant adjacent to said second meniscus forming feature defined by said second meniscus forming feature.

34. The package of claim 33, wherein said second meniscus forming feature comprises a physical transition that creates a meniscus when a liquid contacts it.

35. The package of claim 33, wherein matrix encapsulant comprises a conversion material, and wherein said intermediate encapsulant is transparent to the wavelength of light emitter by said emitter and said conversion material, and wherein said intermediate encapsulant has a higher index of refraction than said matrix encapsulant.

36. An emitter package, comprising:

a solid state emitter having a first meniscus forming feature;

an encapsulant on a surface of said solid state emitter and at least partially covering said surface, said first meniscus forming feature forming said encapsulant in a substantially dome-shape on said surface.

37. The emitter package of claim 36, wherein said first meniscus holding feature comprises an edge of said solid state emitter.

38. The package of claim 36, wherein said first meniscus forming feature comprises a physical transition.

39. The package of claim 36, further comprising a second meniscus holding feature.