Uniform emission LED package

• US 8,969,908 B2
• Filed: 04/04/2006
• Issued: 03/03/2015
• Est. Priority Date: 04/04/2006
• Status: Active Grant

• Current Assignee: Creeled Incorporated
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Negley, Gerald, Leung, Michael, Becerra, Maryanne, Tarsa, Eric, Andrews, Peter
• Primary Examiner(s): SANDVIK, BENJAMIN P
• Application Number:
  US11/398,214
• Publication Number:
  US 20070228387A1
• Time in Patent Office: 3,255 Days
• Field of Search: 257/100
• US Class Current: 257/100
• 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 integral to said submount and around said solid state emitter; and

an encapsulant matrix on said surface of said submount and covering said solid state emitter, said encapsulant matrix 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, wherein said meniscus forming feature comprises an edge of said surface;

a second meniscus forming feature around said first meniscus forming feature; and

an intermediate encapsulant over said encapsulant matrix, the size and shape of said intermediate encapsulant at least partially defined by the size and shape of said second meniscus forming feature, wherein said second meniscus forming feature comprises an edge of said submount.

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 has a circular, square, rectangular or octagonal shape around said emitter.

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

8. The package of claim 1, wherein said encapsulant matrix is in a dome-shape.

9. The package of claim 8, wherein said second meniscus forming feature comprises a physical transition that creates a meniscus when a liquid contacts it.

10. The package of claim 8, wherein said intermediate encapsulant has a higher index of refraction than said encapsulant matrix.

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

12. The package of claim 11, comprising a secondary encapsulant covering said encapsulant matrix and said submount.

13. The package of claim 12, wherein said encapsulant matrix comprises a conversion material, and wherein said secondary encapsulant is transparent to the wavelength of light emitted by said emitter and said conversion material, and wherein said secondary encapsulant has a higher index of refraction than said encapsulant matrix.

14. 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 encapsulant matrix 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, wherein said first meniscus forming feature has a square shape with notches at the corners.

15. 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 encapsulant matrix 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;

a second meniscus forming feature around said first meniscus forming feature; and

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,

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, said first meniscus holding feature comprising the edge of said upper portion, and said second meniscus holding feature comprising the edge of said lower portion.

16. An emitter package, comprising:

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

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

an intermediate encapsulant over said encapsulant matrix in a dome-shape, wherein at least a surface of said intermediate encapsulant conforms to the shape of said encapsulant matrix; and

a second meniscus forming feature around said first meniscus forming feature, wherein the outer edge of said intermediate encapsulant adjacent to said second meniscus forming feature is defined by said second meniscus forming feature, and wherein said second meniscus forming feature comprises an edge of said body.

17. The package of claim 16, 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.

18. The package of claim 16, wherein said solid state emitter comprises a light emitting diode.

19. The package of claim 16, wherein said encapsulant further comprises a conversion material.

20. The package of claim 16, wherein said first meniscus forming feature comprises a physical transition that creates a meniscus when a liquid contacts it.

21. The package of claim 16, wherein said second meniscus forming feature comprises a physical transition that creates a meniscus when a liquid contacts it.

22. The package of claim 16, wherein said encapsulant matrix comprises a conversion material, and wherein said intermediate encapsulant has a higher index of refraction than said encapsulant matrix.

23. An emitter package comprising:

a submount;

a solid state emitter mounted to a surface of said submount, said submount comprising inner and outer meniscus forming features, integral to said submount, around said solid state emitter;

an first encapsulant on said surface of said submount and covering said solid state emitter, the shape of said first encapsulant at least partially defined by shape of said inner meniscus forming feature; and

a second encapsulant on said surface of said submount and covering said first encapsulant, the shape of said second encapsulant at least partially defined by the shape of said outer meniscus forming feature and wherein at least a surface of said second encapsulant conforms to the shape of said first encapsulant, and wherein said second encapsulant has a higher index of refraction than said first encapsulant.

24. An emitter package, comprising:

a submount;

a solid state emitter mounted to said submount, said submount comprising a non-circular meniscus forming feature, integral to said submount, around said solid state emitter; and

an encapsulant matrix on said submount and covering said solid state emitter, the size and shape of said encapsulant matrix at least partially defined by the dimensions and shape of said non-circular meniscus forming feature; and

a second encapsulant on said surface of said submount and covering said encapsulant matrix wherein at least a surface of said second encapsulant conforms to the shape of said encapsulant matrix, wherein said non-circular meniscus forming feature is substantially rectangular with rounded notches in at least one of the corners.

25. An emitter package, comprising:

a submount;

a solid state emitter mounted to said submount, said submount comprising a non-circular meniscus forming feature, integral to said submount, around said solid state emitter; and

an encapsulant matrix on said submount and covering said solid state emitter, the size and shape of said encapsulant matrix at least partially defined by the dimensions and shape of said non-circular meniscus forming feature; and

a second encapsulant on said surface of said submount and covering said encapsulant matrix wherein at least a surface of said second encapsulant conforms to the shape of said encapsulant matrix, wherein said meniscus forming feature is plus-shaped.