OPTICAL PREFORMS FOR SOLID STATE LIGHT EMITTING DICE, AND METHODS AND SYSTEMS FOR FABRICATING AND ASSEMBLING SAME

• US 20080121911A1
• Filed: 11/28/2006
• Published: 05/29/2008
• Est. Priority Date: 11/28/2006
• Status: Abandoned Application

• Current Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Toquin, Ronan P. Le, Andrews, Peter S.
• Application Number:
  US11/563,840
• Publication Number:
  US 20080121911A1
• Time in Patent Office: Days
• US Class Current: 257/98
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• 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 2933/0091 Scattering means in or on the semiconductor body or semiconductor body package H01L33/22 takes precedence
• CPC Class Codes: H01L 33/505 characterised by the shape, e.g. plate or foil
• CPC Class Codes: H01L 33/58 Optical field-shaping elements

Abstract

A preform is attached to a solid state light emitting die. One or more optical elements, such as a photoluminescent element, a refracting element, a filtering element, a scattering element, a diffusing element or a reflecting element, is included in and/or on the preform. For example, the preform may be a glass preform with phosphor particles suspended therein. The preform may be fabricated using microelectronic manufacturing techniques, and may be placed on the solid state light emitting die using pick and place techniques.

Claims

1. A solid state light emitting device comprising:

a solid state light emitting die that is configured to emit light upon energization thereof;

a preform that is configured to allow at least some light that is emitted from the solid state light emitting die to pass therethrough;

a layer that attaches and optically couples the preform and the solid state light emitting die to one another; and

an optical element in and/or on the preform that is configured to modify at least some of the light that is emitted from the solid state light emitting die.

2. A device according to claim 1 wherein the preform comprises glass.

3. A device according to claim 1 wherein the preform comprises a silicone-based material.

4. A device according to claim 1 wherein the preform comprises an inflexible material.

5. A device according to claim 1 wherein the solid state light emitting die includes an external contact pad and wherein the preform is shaped so as to expose the external contact pad.

6. A device according to claim 1 wherein the optical element comprises a photoluminescent element, an optical refracting element, an optical filtering element, an optical scattering element, an optical diffusing element, an optical reflecting element and/or another preform, in and/or on the preform.

7. A device according to claim 1 further comprising an electrical element in and/or on the preform.

8. A device according to claim 1 wherein the preform is of variable thickness.

9. A device according to claim 1 wherein the preform includes a preform side wall that is configured to extend along a side wall of the solid state light emitting die.

10. A device according to claim 1 wherein the optical element is configured to modify at least some of the light that is emitted from the solid state light emitting die by changing amplitude, frequency and/or direction of at least some of the light that is emitted from the solid state light emitting die.

11. A device according to claim 1 wherein the preform is a first preform, the layer is a first layer and the optical element is a first optical element, the solid state light emitting device further comprising:

a second preform that is configured to allow at least some light that is emitted from the solid state light emitting die to pass therethrough;

a second layer that attaches and optically couples the second preform and the first preform to one another remote from the solid state light emitting die; and

a second optical element in and/or on the second preform that is configured to further modify at least some of the light that is emitted from the solid state light emitting die.

12. A device according to claim 1 wherein the preform is of same shape and size as a surface of the solid state light emitting die.

13. A device according to claim 1 wherein the preform extends beyond a surface of the solid state light emitting die.

14. A device according to claim 1 wherein the preform comprises a suspension of phosphor particles in glass.

15. A device according to claim 14 wherein the preform comprises between about 30 and about 95 weight percent phosphor.

16. A device according to claim 15 wherein the preform further comprises about 0.001 to about 1 weight percent optical scattering particles.

17. A device according to claim 15 wherein the preform comprises a textured surface.

18. A device according to claim 15 wherein the solid state light emitting die includes an external contact pad and wherein the preform is shaped so as to expose the external contact pad.

19. A device according to claim 1 wherein the layer comprises an adhesive layer that adhesively attaches and optically couples the preform and the solid state light emitting die to one another.

20. A device according to claim 1 further comprising a submount that is connected to the solid state light emitting die that includes the preform thereon.

21. A device according to claim 1 wherein the solid state light emitting die is a semiconductor light emitting diode die.

22. A solid state light emitting device comprising:

a solid state light emitting die that is configured to emit light upon energization thereof, and

a glass preform including phosphor particles suspended therein, on the solid state light emitting die.

23. A device according to claim 22 wherein the solid state light emitting die includes an external contact pad and wherein the glass preform including phosphor particles suspended therein is shaped so as to expose the external contact pad.

24. A device according to claim 22 further comprising an electrical element in and/or on the glass preform including phosphor suspended therein.

25. A device according to claim 22 wherein the glass preform including phosphor particles suspended therein extends beyond a surface of the solid state light emitting die.

26. A device according to claim 22 wherein the glass preform including phosphor particles suspended therein comprises between about 30 and about 95 weight percent phosphor.

27. A device according to claim 26 wherein the glass preform including phosphor particles suspended therein further comprises about 0.001 to about 1 weight percent optical scattering particles.

28. A device according to claim 22 wherein the glass preform including phosphor particles suspended therein comprises a textured surface.

29. A device according to claim 22 wherein the phosphor particles comprise Ce:

YAG phosphor.

30. An optical processing device for a solid state light emitting die comprising:

a glass preform that is sized and shaped to attach to the solid state light emitting die, the glass preform including phosphor particles suspended therein.

31. A device according to claim 30 wherein the solid state light emitting die includes an external contact pad and wherein the glass preform including phosphor particles suspended therein is shaped so as to expose the external contact pad.

32. A device according to claim 30 further comprising an electrical element in and/or on the glass preform including phosphor suspended therein.

33. A device according to claim 30 wherein the glass preform including phosphor particles suspended therein comprises between about 30 and about 95 weight percent phosphor.

34. A device according to claim 33 wherein the glass preform including phosphor particles suspended therein further comprises about 0.001 to about 1 weight percent optical scattering particles.

35. A device according to claim 30 wherein the glass preform including phosphor particles suspended therein comprises a textured surface.

36. A device according to claim 30 wherein the phosphor particles comprise Ce:

YAG phosphor.

37. An optical processing precursor for solid state light emitting dice comprising:

a substrate;

a plurality of preforms on the substrate that are sized and shaped to attach to the solid state light emitting dice, a respective preform being configured to allow at least some light that is emitted from a respective solid state light emitting die to pass therethrough; and

an optical element in and/or on a respective preform that is configured to modify at least some of the light that is emitted from the respective solid state light emitting die.

38. A precursor according to claim 37 wherein the preforms comprise singulated preforms.

39. A precursor according to claim 38 wherein the singulated preforms comprise flexible material and wherein the substrate comprises a singulated substrate.

40. A precursor according to claim 38 wherein the singulated preforms comprise glass and wherein the optical element comprises phosphor particles suspended in the singulated glass preforms.

41. A method of fabricating a solid state light emitting device comprising:

attaching a preform and a solid state light emitting die to one another, wherein the preform is configured to allow at least some light that is emitted from the solid state light emitting die to pass therethrough and the preform includes an optical element therein and/or thereon that is configured to modify at least some of the light that is emitted from the solid state light emitting die.

42. A method according to claim 41 wherein attaching comprises picking the preform from a substrate and placing the preform that was picked onto the solid state light emitting die.

43. A method according to claim 42 wherein placing is preceded by coating adhesive on the preform and/or the solid state light emitting device.

44. A method according to claim 42 wherein picking is preceded by singulating the preform.

45. A method of fabricating a preform for a solid state light emitting device comprising:

suspending phosphor particles in glass.

46. A method according to claim 45 wherein suspending comprises:

mixing glass frit and phosphor particles; and

heating to melt the glass frit and form a glass preform including the phosphor particles suspended therein.

47. A method according to claim 45 wherein suspending comprises:

mixing phosphor particles into molten glass; and

allowing the molten glass to cool.