Matrix material including an embedded dispersion of beads for a light-emitting device

• US 20090001390A1
• Filed: 06/29/2007
• Published: 01/01/2009
• Est. Priority Date: 06/29/2007
• Status: Active Grant

• Current Assignee: LED Engin, Inc. (Ams-Osram AG)
• Original Assignee: Ledengin, Inc. (Ams-Osram AG)
• Inventors: Yan, Xiantao, Mei, Zequn
• Granted Patent: US 8,324,641 B2
• Time in Patent Office: Days
• US Class Current: 257/89
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• 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 2933/0091 Scattering means in or on the semiconductor body or semiconductor body package H01L33/22 takes precedence
• CPC Class Codes: H01L 33/50 Wavelength conversion elements
• CPC Class Codes: H01L 33/56 Materials, e.g. epoxy or silicone resin

Abstract

A light-emitting device has a light source disposed on a support. A matrix material including a dispersion of beads is disposed over the light source. The refractive index of the beads is different from the refractive index of the matrix material. The light source may include an LED. The matrix material may include a lens.

Claims

1. A light-emitting device comprising:

a support;

a light source disposed on the support;

a matrix material having a first refractive index disposed over the light source; and

a dispersion of beads within the matrix material, the beads having a second refractive index different than the first refractive index.

2. The light-emitting device of claim 1, wherein the first refractive index is less than the second refractive index.

3. The light-emitting device of claim 1, wherein the light source comprises a light-emitting diode.

4. The light-emitting device of claim 1, wherein the light source comprises a plurality of light-emitting elements.

5. The light-emitting device of claim 1, wherein the light source comprises a blue light-emitting element, a red light-emitting element and a green light-emitting element.

6. The light-emitting device of claim 1, wherein the support includes aluminum nitride.

7. The light-emitting device of claim 1, wherein the matrix material includes glass.

8. The light-emitting device of claim 7, wherein the beads include glass beads.

9. The light-emitting device of claim 1, wherein the matrix material includes silicone.

10. The light-emitting device of claim 1, wherein the matrix material includes plastic.

11. The light-emitting device of claim 1, wherein the support comprises a package including a cavity.

12. The light-emitting device of claim 11, wherein the matrix material is disposed within the cavity.

13. The light-emitting device of claim 12, further comprising a lens disposed over the matrix material.

14. The light-emitting device of claim 11, wherein the matrix material comprises a lens disposed over the cavity.

15. The light-emitting device of claim 11, wherein the matrix material comprises a thermal barrier layer disposed within the cavity.

16. The light-emitting device of claim 11, wherein the matrix material comprises an adhesive layer disposed within the cavity.

17. The light-emitting device of claim 11, wherein the matrix material comprises a refractive index matching layer disposed within the cavity.

18. The light-emitting device of claim 11, wherein the matrix material comprises a phosphor layer disposed within the cavity.

19. The light-emitting device of claim 1, wherein the first refractive index is greater than about 1.44 and less than about 1.60.

20. The light-emitting device of claim 1, wherein the beads include plastic beads.

21. The light-emitting device of claim 1, wherein the beads include silicone beads.

22. The light-emitting device of claim 1, wherein a diameter of the beads is less than about 10 microns.

23. The light-emitting device of claim 1, wherein a diameter of the beads is greater than about 0.3 microns and less than about 20 microns.

24. The light-emitting device of claim 1, wherein an amount of beads within the matrix material is greater than about 1 percent and less than about 80 percent by weight.

25. The light-emitting device of claim 1, wherein an amount of beads within the matrix material is greater than about 2 percent and less than about 10 percent by weight.

26. The light-emitting device of claim 16, wherein the adhesive layer includes silicone.

27. A method of mixing light from two light sources to produce a uniform colored light over a range of angles, the method comprising:

emitting light from two light sources disposed on a support each source emitting a different colored light; and

transmitting the light from the two light sources through a matrix material having a first refractive index and including beads having a second refractive index dispersed within the matrix material.

28. The method of claim 27, wherein the matrix material comprises plastic.