LED Device Architecture Employing Novel Optical Coating and Method of Manufacture

• US 20120256159A1
• Filed: 04/01/2010
• Published: 10/11/2012
• Est. Priority Date: 12/30/2009
• Status: Abandoned Application

• Current Assignee: Newport Corporation (MKS Instruments Incorporated)
• Original Assignee: Newport Corporation (MKS Instruments Incorporated)
• Inventors: Knapp, Jamie
• Application Number:
  US13/513,823
• Publication Number:
  US 20120256159A1
• Time in Patent Office: Days
• US Class Current: 257/9
• CPC Class Codes: H01L 33/005 Processes
• CPC Class Codes: H01L 33/10 with a light reflecting structure, e.g. semiconductor Bragg reflector
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector
• CPC Class Codes: H01L 33/505 characterised by the shape, e.g. plate or foil

Abstract

An improved LED device is disclosed and includes at least one active layer in communication with an energy source and configured to emit a first electromagnetic signal within a first wavelength range and at least a second electromagnetic signal within at least a second wavelength range, a substrate configured to support the active layer, at least one coating layer formed from alternating layers of silicon carbide and alumina applied to a surface of the substrate, the coating layer configured to reflect at least 95% of the first electromagnetic signal at the first wavelength range and transmit at least 95% of the second electromagnetic signal at the second wavelength range, at least one metal layer applied to the coating layer and configured to transmit the second electromagnetic signal at the second wavelength range therethrough, and an encapsulation device positioned to encapsulate the active layer.

Claims

1. An improved LED device, comprising:

a substrate;

at least one coating layer applied to a surface of the substrate, the coating layer formed from alternating thin film layers of alumina and silicon carbide, the coating layer configured to reflect at least 95% of a first electromagnetic signal at a first wavelength range and transmit at least 95% of a second electromagnetic signal at a second wavelength range;

at least one active layer positioned on the substrate and in communication with an energy source configured to emit the first electromagnetic signal within the first wavelength range and at least the second electromagnetic signal within at least the second wavelength range; and

an encapsulation device positioned to encapsulate the active layer.

2. The device of claim 1 wherein the substrate comprises silicon carbide.

3. The device of claim 1 wherein the substrate comprises sapphire.

4. The device of claim 1 wherein the first wavelength range is from about 430 nm to about 500 nm.

5. The device of claim 1 wherein the second wavelength is greater than about 500 nm.

6. The device of claim 1 wherein the active layer comprises a multi-quantum well device.

7. The device of claim 1 further comprising a first coating layer positioned between the active layer and the substrate and at least a second coating layer positioned on a surface opposing the surface having the active layer applied thereto.

8. The device of claim 1 wherein the encapsulation device includes at least one dopant therein.

9. The device of claim 8 wherein the dopant is configured to fluoresce when illuminated with the first electromagnetic signal within the first wavelength range.

10. The device of claim 8 wherein the dopant comprises phosphor.

11. The device of claim 1 further comprising a metal layer applied to the coating layer.

12. The device of claim 11 wherein the metal layer comprises aluminum,

13. The device of claim 11 wherein the metal layer comprises copper.

14. An improved LED device, comprising:

a substrate;

at least one coating layer applied to a surface of the substrate, the coating layer formed from alternating thin film layers of alumina and silicon carbide, the coating layer configured to reflect at least 95% of a first electromagnetic signal at a first wavelength range at all angles from about 0 degree to about 90 degrees and transmit at least 95% and transmit at least 95% of a second electromagnetic signal at a second wavelength range;

at least one metal layer applied to the coating layer;

at least one active layer positioned on the substrate and in communication with an energy source configured to emit the first electromagnetic signal within the first wavelength range and at least the second electromagnetic signal within at least the second wavelength range; and

an encapsulation device positioned to encapsulate the active layer.

15. The device of claim 14 wherein the substrate comprises silicon carbide.

16. The device of claim 14 wherein the substrate comprises sapphire.

17. The device of claim 14 wherein the first wavelength range is from about 430 nm to about 500 nm.

18. The device of claim 14 wherein the second wavelength is greater than about 500 nm.

19. The device of claim 14 wherein the active layer comprises a multi-quantum well device.

20. The device of claim 14 further comprising a first coating layer positioned between the active layer and the substrate and at least a second coating layer positioned on a surface opposing the surface having the active layer applied thereto.

21. The device of claim 14 wherein the encapsulation device includes at least one dopant therein.

22. The device of claim 21 wherein the dopant is configured to fluoresce when illuminated with the first electromagnetic signal within the first wavelength range.

23. The device of claim 21 wherein the dopant comprises phosphor.

24. The device of claim 14 wherein the metal layer comprises aluminum,

25. The device of claim 14 wherein the metal layer comprises copper.

26. A method of manufacturing a LED device, comprising:

applying at least one coating layer formed from alternating layers of alumina and silicon carbide to a substrate, the coating configured to reflect at least 95% of a first electromagnetic signal at a first wavelength range and transmit at least 95% of a second electromagnetic signal at a second wavelength range to a surface of the substrate;

growing an epitaxial layer capable of emitting electromagnetic radiation within the first wavelength range and at least the second electromagnetic radiation within at least the second wavelength range when subjected to an electric charge on the substrate; and

encapsulating at least the active layer within an encapsulation device.

27. The method of claim 26 further comprising pre-stressing the substrate with the coating layer to compensate for stress from the application of the epitaxial layer.

28. The method of claim 26 further comprising applying a metal layer to the coating layer.

29. The method of claim 26 further comprising applying a thermal paste to the coating layer to affix the LED device to material substrate.

30. A method of manufacturing a LED device, comprising:

providing a silicon carbide substrate;

growing an epitaxial layer capable of emitting electromagnetic radiation within a first wavelength range and at least a second electromagnetic radiation within at least a second wavelength range when subjected to an electric charge on the substrate;

applying at least one coating layer formed from alternating layers of alumina and silicon carbide to a substrate, the coating configured to reflect at least 95% of the first electromagnetic signal at the first wavelength range and transmit at least 95% of the second electromagnetic signal at the second wavelength range to a surface of the substrate; and

encapsulating at least the active layer within an encapsulation device.

31. The method of claim 30 further comprising stressing the substrate with the coating layer to compensate for stress from the application of the epitaxial layer.

32. The method of claim 30 further comprising applying a metal layer to the coating layer.

33. The method of claim 30 further comprising applying a thermal paste to the coating layer to affix the LED device to material substrate.