WAFER-TYPE LIGHT EMITTING DEVICE HAVING PRECISELY COATED WAVELENGTH-CONVERTING LAYER

• US 20110316017A1
• Filed: 05/27/2011
• Published: 12/29/2011
• Est. Priority Date: 06/29/2010
• Status: Active Grant

• Current Assignee: Semileds Optoelectronics Company Limited (SemiLEDs Inc)
• Original Assignee: Semileds Optoelectronics Company Limited (SemiLEDs Inc)
• Inventors: Liu, Wen-Huang, Chu, Chen-Fu, Chang, Yuan-Hsiao, Kao, Hung-Jen, Dan, Chung-Che, Fan, Feng-Hsu
• Granted Patent: US 8,648,370 B2
• Time in Patent Office: Days
• US Class Current: 257/91
• CPC Class Codes: H01L 33/504 Elements with two or more wavelength conversion materials
• CPC Class Codes: H01L 33/505 characterised by the shape, e.g. plate or foil

Abstract

The invention relates to a wafer-type light emitting device having a substrate, one or more light emitting semiconductors formed on the substrate, one or more frames provided over the one or more light emitting semiconductors, and one or more wavelength-converting layers applied on the one or more light emitting semiconductors and confined by the one or more frames, wherein the wafer-type light emitting device is diced into a plurality of separate light emitting units.

Claims

1. A wafer-type light emitting device comprising:

a substrate;

one or more light emitting semiconductors formed on the substrate;

one or more frames provided over the one or more light emitting semiconductors; and

one or more wavelength-converting layers applied on the one or more light emitting semiconductors and confined by the one or more frames,

wherein the wafer-type light emitting device is diced into a plurality of separate, individual light emitting units.

2. The wafer-type light emitting device of claim 1, wherein the one or more frames are capable of extending to a side portion of the one or more light emitting semiconductors.

3. The wafer-type light emitting device of claim 1, wherein the light emitting units are capable of emitting a light having a peak wavelength ranging between about 200 nm and about 500 nm.

4. The wafer-type light emitting device of claim 1, wherein the one or more wavelength-converting layers are applied using at least one of precise dispensing, precise stamping, precise jetting, and screen printing.

5. The wafer-type light emitting device of claim 1, wherein the one or more wavelength-converting layers include fluorescent particles mixed with one or more organic chemicals.

6. The wafer-type light emitting device of claim 5, wherein a weight ratio of the fluorescent particles to the one or more organic chemicals is about 0.6 to 8.

7. The wafer-type light emitting device of claim 5, wherein the one or more organic chemicals are silicone resin and/or epoxy resin.

8. The wafer-type light emitting device of claim 1, wherein the one or more wavelength-converting layers include fluorescent particles mixed with a glass.

9. The wafer-type light emitting device of claim 8, wherein a weight ratio of the fluorescent particles to the glass is about 0.6 to 8.

10. The wafer-type light emitting device of claim 8, wherein the one or more wavelength-converting layers mixed with the glass are applied using at least one of precise dispensing, precise stamping, precise jetting, and screen printing.

11. The wafer-type light emitting device of claim 10, wherein the one or more wavelength-converting layers mixed with the glass are applied at a temperature ranging between about 100°

C. and about 500°

C.

12. The wafer-type light emitting device of claim 1, wherein the one or more wavelength-converting layers have a convex, a concave, a flat, or a pyramid shape.

13. The wafer-type light emitting device of claim 1, wherein the one or more frames are made of a transparent material.

14. The wafer-type light emitting device of claim 13, wherein the transparent material is epoxy resin, silicone resin, polyimide resin, glass, quartz, acryl resin, polycarbonate resin, SU-8 resist, BCB resist, or parylene resin.

15. The wafer-type light emitting device of claim 1, wherein the one or more frames are provided using at least one of spin coating, dip coating, chemical vapor deposition, thermal evaporation, and e-beam evaporation.

16. The wafer-type light emitting device of claim 1, wherein the one or more frames are a single metallic layer or multiple metallic layers.

17. The wafer-type light emitting device of claim 1, wherein the one or more frames have a thickness of about 0.1 μ

m to about 200 μ

m.

18. The wafer-type light emitting device of claim 1, wherein the one or more wavelength-converting layers have a thickness of about 1 μ

m to about 200 μ

m.

19. The wafer-type light emitting device of claim 1, further comprising:

a light diffusion layer provided on the one or more wavelength-converting layers.

20. The wafer-type light emitting device of claim 1, wherein the substrate is opaque.

21. The wafer-type light emitting device of claim 20, wherein the substrate is metal, ceramic, or semiconductor.

22. The wafer-type light emitting device of claim 21, further comprising:

a reflection layer provided between the substrate and the one or more light emitting semiconductors.

23. The wafer-type light emitting device of claim 1, wherein a surface of the one or more light emitting semiconductors that is adjacent to the one or more wavelength-converting layers is roughened.

24. The wafer-type light emitting device of claim 1, wherein the one or more wavelength-converting layers undergo a heat treatment.

25. The wafer-type light emitting device of claim 24, wherein a temperature of the heat treatment is between about 60°

C. and about 300°

C.

26. The wafer-type light emitting device of claim 1, wherein the one or more light emitting semiconductors include:

a p-type semiconductor layer formed on the substrate;

an activation layer provided on the p-type semiconductor layer; and

an n-type semiconductor layer provided on the activation layer.

27. The wafer-type light emitting device of claim 1, wherein the one or more wavelength-converting layers are capable of encapsulating a portion of the one or more frames.

28. The wafer-type light emitting device of claim 2, wherein the one or more wavelength-converting layers are capable of encapsulating a side portion of the one or more light emitting semiconductors.