Light-emitting diode with UV-blocking nano-particles

• US 20070108463A1
• Filed: 11/17/2005
• Published: 05/17/2007
• Est. Priority Date: 11/17/2005
• Status: Abandoned Application

• Current Assignee: Avago Technologies ECBU IP Singapore Pte Limited (Broadcom, Inc.)
• Original Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Inventors: Chua, Janet, Lau, Yue
• Application Number:
  US11/283,026
• Publication Number:
  US 20070108463A1
• Time in Patent Office: Days
• US Class Current: 257/100
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• 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 2924/181 Encapsulation
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating
• CPC Class Codes: H01L 33/56 Materials, e.g. epoxy or silicone resin

Abstract

A light-emitting device has an encapsulated light-emitter. Nano-particles substantially transparent to visible light block UV light.

Claims

1. A light-emitting device having:

encapsulant;

a light-emitter within the encapsulant; and

UV-blocking nano-particles substantially transparent to visible light.

2. The light-emitting device of claim 1 wherein the UV-blocking nano-particles comprise nano-alumina.

3. The light-emitting device of claim 1 wherein the UV-blocking nano-particles are incorporated in a layer disposed on the encapsulant.

4. The light-emitting device of claim 3 wherein the layer comprises nano-alumina comprises between about 8 weight percent and about 17 weight percent in an epoxy resin.

5. The light-emitting device of claim 4 wherein the encapsulant comprises the epoxy resin.

6. The light-emitting device of claim 5 wherein the encapsulant further comprises between about 5 weight percent and about 10 weight percent nano-alumina.

7. The light emitting device of claim 5 wherein the encapsulant further comprises nano-silica.

8. The light-emitting device of claim 1 wherein the UV-blocking nano-particles are disposed in the encapsulant.

9. The light-emitting device of claim 8 wherein the UV-blocking nano-particles comprise between about 8 weight percent and about 17 weight percent nano-alumina in a liquid encapsulant precursor material to provide an encapsulant formulation.

10. The light-emitting device of claim 9 wherein the liquid encapsulant precursor is an elastomeric resin.

11. The light-emitting device of claim 9 wherein the liquid encapsulant precursor is an epoxy resin.

12. The light-emitting device of claim 11 wherein the encapsulant formulation further comprises between about 3.5 weight percent and about 5 weight percent nano-titania.

13. The light-emitting device of claim 11 wherein the encapsulant formulation further comprises between about 12.5 weight percent and about 20 weight percent nano-silica.

14. The light-emitting device of claim 11 wherein the epoxy resin has an initial viscosity less than about 800 centipoise.

15. The light-emitting device of claim 1 wherein the light emitter is an LED.

16. The light-emitting device of claim 15 wherein the LED has an operating current of at least 20 mA.

17. The light-emitting device of claim 15 wherein the LED emits UV light.