Semiconductor light emitting devices including flexible unitary film on aluminum nitride substrate

• US 8,455,909 B2
• Filed: 01/23/2012
• Issued: 06/04/2013
• Est. Priority Date: 03/29/2004
• Status: Active Grant

• Current Assignee: CREE Led Incorporated (Smart Global Holdings Incorporated)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Negley, Gerald H.
• Primary Examiner(s): Jackson, Jr., Jerome
• Assistant Examiner(s): Chen, Yu
• Application Number:
  US13/356,046
• Publication Number:
  US 20120119221A1
• Time in Patent Office: 498 Days
• Field of Search: 257 98-100, 257/791, 257/E33.059, 257/E33.073, 257/E23.12, 313/512
• US Class Current: 257/98
• 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 33/486 adapted for surface mounting
• 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 33/58 Optical field-shaping elements
• CPC Class Codes: H01L 33/62 Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls

Abstract

Semiconductor light emitting devices include an aluminum nitride substrate, a light emitting diode on a face of the substrate and flexible silicone film that includes a silicone lens on the face of the substrate. The light emitting diode emits light through the silicone lens.

Claims

1. A semiconductor light emitting device comprising:

a substrate comprising aluminum nitride;

a light emitting diode on a face of the substrate comprising aluminum nitride; and

a flexible unitary film comprising silicone that extends conformally on the face of the substrate comprising aluminum nitride outside the light emitting diode and that also extends on the light emitting diode, the flexible unitary film comprising silicone including therein a lens comprising silicone adjacent the light emitting diode, such that the light emitting diode emits light through the lens.

2. A device according to claim 1 wherein the flexible unitary film comprising silicone is attached to the substrate comprising aluminum nitride such that the flexible unitary film comprising silicone conforms to the light emitting diode as it expands and contracts during operation thereof.

3. A device according to claim 2 further comprising phosphor between the lens and the light emitting diode.

4. A device according to claim 3 wherein the lens includes a concave inner surface adjacent the light emitting diode and wherein the phosphor comprises a conformal phosphor layer on the concave inner surface.

5. A device according to claim 3 further comprising an optical coupling media between the phosphor and the light emitting diode.

6. A device according to claim 2 further comprising an attachment element that is configured to attach the flexible unitary film and the substrate comprising aluminum nitride to one another such that the flexible unitary film comprising silicone conforms to the light emitting diode as it expands and contracts during operation thereof.

7. A device according to claim 1 wherein at least a portion of the flexible unitary film comprising silicone that overlies the light emitting diode is transparent to the light and wherein at least a portion of the flexible unitary film comprising silicone that extends conformally onto the face of the substrate comprising aluminum nitride beyond the light emitting diode is opaque to the light.

8. A device according to claim 7 wherein the flexible unitary film comprising silicone is attached to the substrate comprising aluminum nitride such that the flexible unitary film comprising silicone conforms to the light emitting diode as it expands and contracts during operation thereof.

9. A device according to claim 8 further comprising phosphor between the lens and the light emitting diode.

10. A device according to claim 9 wherein the lens includes a concave inner surface adjacent the light emitting diode and wherein the phosphor comprises a conformal phosphor layer on the concave inner surface.

11. A device according to claim 9 further comprising an optical coupling media between the phosphor and the light emitting diode.

12. A device according to claim 8 further comprising an attachment element that is configured to attach the flexible unitary film and the substrate comprising aluminum nitride to one another such that the flexible unitary film comprising silicone conforms to the light emitting diode as it expands and contracts during operation thereof.

13. A device according to claim 1 wherein at least a portion of the flexible unitary film comprising silicone that overlies the light emitting diode comprises a first material and wherein at least a portion of the flexible unitary film comprising silicone that extends conformally onto the face of the substrate comprising aluminum nitride beyond the light emitting diode comprises a second material that is different from the first material.

14. A device according to claim 13 wherein the flexible unitary film comprising silicone is attached to the substrate comprising aluminum nitride such that the flexible unitary film comprising silicone conforms to the light emitting diode as it expands and contracts during operation thereof.

15. A device according to claim 14 further comprising phosphor between the lens and the light emitting diode.

16. A device according to claim 15 wherein the lens includes a concave inner surface adjacent the light emitting diode and wherein the phosphor comprises a conformal phosphor layer on the concave inner surface.

17. A device according to claim 15 further comprising an optical coupling media between the phosphor and the light emitting diode.

18. A device according to claim 14 further comprising an attachment element that is configured to attach the flexible unitary film and the substrate comprising aluminum nitride to one another such that the flexible unitary film comprising silicone conforms to the light emitting diode as it expands and contracts during operation thereof.