Semiconductor light emitting devices including patternable films comprising transparent silicone and phosphor, and methods of manufacturing same

• US 20060061259A1
• Filed: 09/23/2004
• Published: 03/23/2006
• Est. Priority Date: 09/23/2004
• Status: Active Grant

• Current Assignee: CREE Led Incorporated (Smart Global Holdings Incorporated)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Negley, Gerald H.
• Granted Patent: US 7,372,198 B2
• Time in Patent Office: Days
• US Class Current: 313/499
• CPC Class Codes: H01L 2224/48463 the connecting portion on the bonding area of the semiconductor or solid-state body being a ball bond
• CPC Class Codes: H01L 33/501 characterised by the materials, e.g. binder

Abstract

Semiconductor light emitting devices include a semiconductor light emitting element having a light emitting surface, and a patternable film including transparent silicone and phosphor on at least a portion of the light emitting surface. The patternable film may be a photopatternable film and/or a printable film including transparent silicone and phosphor. The patternable film includes an aperture therein that exposes a portion of a light emitting surface, and a bond pad is provided on the light emitting surface in the aperture. A wire bond may be provided on the bond pad. Related methods of fabricating semiconductor light emitting devices are also provided.

Claims

1. A semiconductor light emitting device comprising:

a semiconductor light emitting element that includes a light emitting surface; and

a patternable film comprising transparent silicone and phosphor on at least a portion of the light emitting surface.

2. A semiconductor light emitting device according to claim 1 wherein the patternable film comprising transparent silicone and phosphor includes an aperture therein that exposes a portion of the light emitting surface, and wherein the semiconductor light emitting device further comprises a bond pad on the exposed portion of the light emitting surface in the aperture.

3. A semiconductor light emitting device according to claim 2 further comprising a wire bond on the bond pad opposite the light emitting surface.

4. A semiconductor light emitting device according to claim 1 wherein the light emitting surface includes a face and a sidewall that extends from the face, and wherein the patternable film comprising transparent silicone and phosphor is on at least a portion of the face and on at least a portion of the sidewall.

5. A semiconductor light emitting device according to claim 4 wherein the patternable film comprising transparent silicone and phosphor is thicker on the at least a portion of the sidewall than on the at least a portion of the face.

6. A semiconductor light emitting device according to claim 5 wherein the patternable film comprising transparent silicone and phosphor is at least 10% thicker on the at least a portion of the sidewall than on the at least a portion of the face.

7. A semiconductor light emitting device according to claim 1 wherein the phosphor is configured to convert at least some light that is emitted from the light emitting surface such that light that emerges from the semiconductor light emitting device appears as white light.

8. A semiconductor light emitting device according to claim 1 further comprising:

a patternable film comprising transparent silicone and free of phosphor, between the light emitting surface and the transparent patternable film comprising silicone and phosphor.

9. A semiconductor light emitting device according to claim 1 wherein the semiconductor light emitting element comprises a first semiconductor light emitting element and wherein the light emitting surface comprises a first light emitting surface, the semiconductor light emitting device further comprising:

a second semiconductor light emitting element that is monolithically integrated with the first semiconductor light emitting element and that includes a second light emitting surface; and

wherein the patternable film comprising transparent silicone and phosphor is on at least a portion of the first and second light emitting surfaces.

10. A semiconductor light emitting device according to claim 1 wherein the semiconductor light emitting element comprises a first semiconductor light emitting element and wherein the light emitting surface comprises a first light emitting surface, the semiconductor light emitting device further comprising:

a second semiconductor light emitting element that includes a second light emitting surface; and

a mounting tape;

wherein the first and second light emitting devices are on the mounting tape and spaced apart from one another; and

wherein the patternable film comprising transparent silicone and phosphor is on at least a portion of the first and second light emitting surfaces.

11. A semiconductor light emitting device according to claim 10 wherein the patternable film comprising transparent silicone and phosphor extends onto the mounting tape between the spaced apart first and second light emitting devices.

12. A semiconductor light emitting device according to claim 11 wherein the first light emitting surface includes a first sidewall facing the second semiconductor light emitting element, wherein the second light emitting surface includes a second sidewall facing the first semiconductor light emitting element and wherein the patternable film comprising transparent silicone and phosphor also extends onto at least a portion of the first and second sidewalls.

13. A semiconductor light emitting device according to claim 1 wherein the patternable film comprising transparent silicone and phosphor comprises a photopatternable film transparent comprising silicone and phosphor.

14. A semiconductor light emitting device according to claim 1 wherein the patternable film comprising transparent silicone and phosphor comprises a printable film comprising transparent silicone and phosphor.

15. A semiconductor light emitting device according to claim 1 wherein the patternable film comprising transparent silicone and phosphor is a first patternable film comprising transparent silicone and a first phosphor, the device further comprising:

a second patternable film comprising transparent silicone and a second phosphor on the first patternable film comprising transparent silicone and a first phosphor, opposite the light emitting surface.

16. A semiconductor light emitting device according to claim 15 wherein the first phosphor comprises a green phosphor and the second phosphor comprises a red phosphor.

17. A method of fabricating a semiconductor light emitting device comprising:

coating a patternable film comprising transparent silicone and phosphor on at least a portion of a light emitting surface of a semiconductor light emitting element.

18. A method according to claim 17 wherein coating comprises coating a photopatternable film comprising transparent silicone and phosphor on the at least a portion of a light emitting surface of a semiconductor light emitting element.

19. A method according to claim 17 wherein coating comprises printing a printable film comprising transparent silicone and phosphor on the at least a portion of a light emitting surface of a semiconductor light emitting element.

20. A method according to claim 18 further comprising:

photopatterning the photopatternable film comprising transparent silicone and phosphor to form an aperture therein that exposes a portion of the light emitting surface.

21. A method according to claim 19 further comprising:

printing the printable film comprising transparent silicone and phosphor on the at least a portion of a light emitting surface of a semiconductor light emitting element to define an aperture therein that exposes a portion of the light emitting surface.

22. A method according to claim 20 further comprising:

forming a bond pad on the exposed portion of the light emitting surface in the aperture.

23. A method according to claim 21 further comprising:

forming a bond pad on the exposed portion of the light emitting surface in the aperture.

24. A method according to claim 22 further comprising:

bonding a wire to the bond pad opposite the light emitting surface.

25. A method according to claim 23 further comprising:

bonding a wire to the bond pad opposite the light emitting surface.

26. A method according to claim 17 wherein the light emitting surface includes a face and a sidewall that extends from the face, and wherein coating comprises coating the patternable film comprising transparent silicone and phosphor on at least a portion of the face and on at least a portion of the sidewall.

27. A method according to claim 26 wherein coating comprises coating the patternable film comprising transparent silicone and phosphor thicker on the at least a portion of the sidewall than on the at least a portion of the face.

28. A method according to claim 27 wherein coating comprises coating the patternable film comprising transparent silicone and phosphor at least 10% thicker on the at least a portion of the sidewall than on the at least a portion of the face.

29. A method according to claim 17 wherein the phosphor is configured to convert at least some light that is emitted from the light emitting surface such that light that emerges from the semiconductor light emitting device appears as white light.

30. A method according to claim 20 wherein photopatterning comprises:

selectively exposing the photopatternable film comprising transparent silicone and phosphor to define the aperture; and

developing the photopatternable film comprising transparent silicone and phosphor that has been exposed, to form the aperture.

31. A method according to claim 30 further comprising:

again developing the photopatternable film comprising transparent silicone and phosphor that has been developed, to enlarge the aperture.

32. A method according to claim 31 wherein the following is performed between developing and again developing:

measuring light emission of the light emitting device; and

wherein again developing is performed if the light emission of the light emitting device that is measured does not conform to at least one predefined parameter.

33. A method according to claim 32 wherein the at least one predefined parameter comprises an emission frequency spectrum.

34. A method according to claim 17 wherein coating is preceded by:

coating a patternable film comprising transparent silicone and free of phosphor on at least a portion of the light emitting surface.

35. A method according to claim 17 wherein coating comprises:

coating a transparent patternable film comprising silicone and phosphor on at least a portion of light emitting surfaces of a plurality of semiconductor light emitting elements that are monolithically integrated.

36. A method according to claim 17 wherein the patternable film comprising transparent silicone and phosphor is a first patternable film comprising transparent silicone and a first phosphor, the method further comprising:

coating a second patternable film comprising transparent silicone and a second phosphor on the first patternable film comprising transparent silicone and a first phosphor.

37. A method according to claim 36 wherein the first phosphor comprises a green phosphor and the second phosphor comprises a red phosphor.

38. A method according to claim 17:

wherein coating is preceded by mounting a plurality of semiconductor light emitting devices including corresponding light emitting surfaces, on a mounting tape; and

wherein coating comprises coating a patternable film comprising transparent silicone and phosphor on at least a portion of the light emitting surfaces of the plurality of semiconductor light emitting elements that are mounted on the mounting tape.

39. A method according to claim 38:

wherein the following is performed between mounting and coating;

stretching the mounting tape to define spaces between adjacent semiconductor light emitting devices; and

wherein coating comprises coating a patternable film comprising transparent silicone and phosphor on at least a portion of the light emitting surfaces of the plurality of semiconductor light emitting elements that are mounted on the mounting tape and on the spaces between adjacent semiconductor light emitting devices.

40. A method according to claim 39 wherein the semiconductor light emitting surfaces include sidewalls and wherein coating comprises:

coating a patternable film comprising transparent silicone and phosphor on at least a portion of the light emitting surfaces of the plurality of semiconductor light emitting elements that are mounted on the mounting tape and on the spaces between adjacent semiconductor light emitting devices so as to coat at least a portion of sidewalls of the semiconductor light emitting elements with the patternable film comprising transparent silicone and phosphor.