Light-emitting device capable of improving the light-emitting efficiency

• US 8,872,202 B2
• Filed: 06/14/2013
• Issued: 10/28/2014
• Est. Priority Date: 12/06/2012
• Status: Active Grant

• Current Assignee: Genesis Photonics Inc., Lite-On Technology Corporation
• Original Assignee: Genesis Photonics Inc.
• Inventors: Huang, Yi-Ru, Huang, Jing-En, Wu, Chih-Ling, Lo, Yu-Yun
• Primary Examiner(s): Sandvik, Benjamin
• Assistant Examiner(s): KHAN, FARID H
• Application Number:
  US13/917,646
• Publication Number:
  US 20140159082A1
• Time in Patent Office: 501 Days
• Field of Search: 257/95
• US Class Current: 257/95
• CPC Class Codes: H01L 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers

Abstract

A light-emitting device including a substrate, a light emitting structure and a coarse structure is provided. The substrate has an upper surface and a lower surface opposite to each other, and an annular side surface connecting the upper surface and the lower surface. The light emitting structure is disposed on the upper surface of the substrate. The coarse structure is formed on the annular side surface of the substrate. A ratio of a thickness of the substrate and a thickness of the coarse structure is greater than or equal to 1 and less than or equal to 20. Therefore, the overall light-emitting efficiency of the light-emitting device may be improved.

Claims

1. A light-emitting device, comprising:

a substrate having an upper surface and a lower surface opposite to each other and an annular side surface connecting the upper surface and the lower surface;

a light emitting structure disposed on the upper surface of the substrate; and

a coarse structure formed on the annular side surface of the substrate, wherein a ratio of a thickness of the substrate and a thickness of the coarse structure is greater than or equal to 1 and less than or equal to 20, a distance from a side of the coarse structure relatively near the upper surface of the substrate to the upper surface of the substrate is greater than or equal to 10 μ

m and less than or equal to 150 μ

m, and a distance from a side of the coarse structure relatively near the lower surface of the substrate to the lower surface of the substrate is greater than or equal to 0 μ

m and less than or equal to 100 μ

m.

2. The light-emitting device of claim 1, wherein the ratio of the thickness of the substrate and the thickness of the coarse structure is greater than or equal to 3 and less than or equal to 10.

3. The light-emitting device of claim 1, wherein the thickness of the coarse structure is greater than or equal to 10 μ

m and less than or equal to 50 μ

m.

4. The light-emitting device of claim 1, wherein the coarse structure is an annular coarse structure.

5. The light-emitting device of claim 4, wherein the annular coarse structure comprises an annular continuous coarse structure.

6. The light-emitting device of claim 1, wherein the coarse structure comprises a plurality of annular coarse structures.

7. The light-emitting device of claim 6, wherein the annular coarse structures are formed on the annular side surface of the substrate in different spacings.

8. The light-emitting device of claim 7, wherein a portion of the annular coarse structures overlap with each other.

9. The light-emitting device of claim 1, wherein the coarse structure is formed by a non-periodic pattern.

10. The light-emitting device of claim 1, wherein the light-emitting device is a flip chip light-emitting device.

11. The light-emitting device of claim 1, wherein the light emitting structure comprises a first electrode, a second electrode, a first type semiconductor layer, a second type semiconductor layer and a light-emitting layer, the light-emitting layer is located between the first type semiconductor layer and the second type semiconductor layer, and the first electrode and the second electrode are respectively disposed on the first type semiconductor layer and the second type semiconductor layer.