WAVELENGTH CONVERTING LIGHT-EMITTING DEVICES AND METHODS OF MAKING THE SAME

• US 20090309114A1
• Filed: 01/16/2009
• Published: 12/17/2009
• Est. Priority Date: 01/16/2008
• Status: Abandoned Application

• Current Assignee: Luminus Devices Incorporated (Sanan Optoelectronics Company Limited)
• Original Assignee: Luminus Devices Incorporated (Sanan Optoelectronics Company Limited)
• Inventors: Zhu, Hao, Lu, Hong, Lim, Michael
• Application Number:
  US12/355,559
• Publication Number:
  US 20090309114A1
• Time in Patent Office: Days
• US Class Current: 257/98
• CPC Class Codes: H01L 2933/0041 relating to wavelength conversion elements
• CPC Class Codes: H01L 33/505 characterised by the shape, e.g. plate or foil
• CPC Class Codes: H01L 33/56 Materials, e.g. epoxy or silicone resin

Abstract

Wavelength converting light-emitting devices and methods of making the same are provided. In some embodiments, the devices include a phosphor material region designed to convert the wavelength of emitted light.

Claims

1. A method of making a wavelength converting light-emitting device, the method comprising:

providing a light-emitting device having a light-emitting surface;

disposing a mask layer over the light-emitting surface, wherein the mask layer exposes a portion of the light-emitting surface; and

disposing a wavelength converting layer over the mask layer and the portion exposed by the mask layer of the light-emitting surface.

2. The method of claim 1, wherein the light-emitting device is an LED.

3. The method of claim 1, further comprising:

lifting-off the mask layer so as to also remove the wavelength converting layer disposed over the mask layer while leaving the wavelength converting layer disposed over the exposed portion of the light-emitting surface so as to form the wavelength converting light-emitting device.

4. The method of claim 1, wherein the light-emitting device includes at least one electrically conductive bond pad disposed on the light-emitting surface, and wherein disposing a mask layer over the light-emitting surface comprises disposing the mask layer over the at least one bond pad.

5. The method of claim 1, wherein the wavelength converting light-emitting device is configured to emit substantially white light.

6. The method of claim 1, wherein the wavelength converting layer comprises a wavelength converting material and a second material.

7. The method of claim 6, wherein the second material comprises a spin-on-glass.

8. The method of claim 1, wherein the wavelength converting material comprises one or more phosphors.

9. The method of claim 1, wherein providing the light-emitting device having the light-emitting surface comprises providing a wafer including a plurality of light-emitting devices, each light-emitting device having a light-emitting surface.

10. The method of claim 9, wherein disposing the mask layer comprises disposing the mask layer over the wafer.

11. The method of claim 9, wherein disposing the wavelength converting layer comprises disposing the wavelength converting material over the wafer.

12. The method of claim 1, wherein disposing the wavelength converting layer comprises a technique selected from the group consisting of spin coating, screen printing or spray coating.

13. The method of claim 1, wherein the wavelength converting layer has an average thickness and a thickness uniformity of less than 30% the average thickness.

14. The method of claim 1, further comprising disposing a second wavelength converting layer over the first wavelength converting layer.

15. A method of making a wavelength converting light-emitting device, the method comprising:

providing a light-emitting device having a light-emitting surface; and

spin coating a wavelength converting layer on the light-emitting surface.

16. The method of claim 15, further comprising forming a bond pad on the light-emitting surface.

17. The method of claim 16, wherein the light-emitting device has an edge and the wavelength converting layer is separated from the bond pad by a distance less than or equal to 0.005 times the length of the edge.

18. The method of claim 16, wherein the light-emitting device has an edge of at least 1 mm.

19. The method of claim 16, further comprising disposing a mask layer over the light-emitting surface prior to spin coating a wavelength converting layer, wherein the mask layer exposes a portion of the light-emitting surface.

20. The method of claim 16, wherein the wavelength converting layer has an average thickness and a thickness uniformity of less than 30% the average thickness.

21. The method of claim 16, further comprising disposing a second wavelength converting layer over the first wavelength converting layer.

22. A light-emitting device comprising:

a multi-layer stack of materials including a light-generating region and a light-emitting surface;

at least one electrically conductive bond pad disposed on the light-emitting surface; and

a wavelength converting layer disposed over the light-emitting surface, the wavelength converting layer comprising a wavelength converting material and a spin-on-glass.

23. The device of claim 22, wherein the wavelength converting layer is absent over the electrically conductive bond pads.

24. The device of claim 22, wherein the light-emitting device is an LED.

25. The device of claim 24, wherein the LED has an edge having a length of at least 1 mm.

26. A light-emitting device comprising:

a multi-layer stack of materials including a light-generating region and a light-emitting surface;

at least one electrically conductive bond pad disposed on the light-emitting surface; and

a wavelength converting layer disposed over the light-emitting surface, wherein the wavelength converting layer is separated from the bond pad by a distance less than or equal to 0.025 times the length of an edge of the light-emitting device.

27. The device of claim 26, wherein the light-emitting device is an LED.

28. The device of claim 26, wherein the LED has an edge having a length of at least 1 mm.

29. The device of claim 26, wherein the wavelength converting layer has an average thickness and a thickness uniformity of less than 30% the average thickness.

30. The device of claim 26, wherein the wavelength converting layer is separated from the bond pad by a distance less than or equal to 0.005 times the length of the edge of the LED die.