Light emitting diode having electrode extensions

• US 8,525,212 B2
• Filed: 12/07/2010
• Issued: 09/03/2013
• Est. Priority Date: 12/29/2009
• Status: Active Grant

• Current Assignee: Sinotechnix LLC
• Original Assignee: Seoul Optodevice Company Limited (Seoul Semiconductor Co., Ltd.)
• Inventors: Kim, Kyoung Wan, Kim, Ye Seul, Yang, Jeong Hee, Kim, Jae Moo
• Primary Examiner(s): Smoot, Stephen W
• Application Number:
  US12/962,365
• Publication Number:
  US 20110156086A1
• Time in Patent Office: 1,001 Days
• Field of Search: 257/E29.329, 257/E23.015, 257/E21.015, 257/E33.065, 438/39
• US Class Current: 257/99
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/38 with a particular shape
• CPC Class Codes: H01L 33/42 Transparent materials

Abstract

An exemplary embodiment of the present invention discloses a light emitting diode including a lower contact layer having a first edge, a second edge opposite to the first edge, a third edge connecting the first edge to the second edge, and a fourth edge opposite to the third edge, a mesa structure arranged on the lower contact layer, the mesa structure including an active layer and an upper contact layer, a first electrode pad arranged on the lower contact layer, a second electrode pad arranged on the mesa structure, a first lower extension and a second lower extension extending from the first electrode pad towards the second edge, distal ends of the first lower extension and the second lower extension being farther away from each other than front ends thereof contacting the first electrode pad, and a first upper extension, a second upper extension, and a third upper extension extending from the second electrode pad. In addition, the first upper extension and the second upper extension extend from the second electrode pad to enclose the first lower extension and the second lower extension, and the third upper extension extends to a region between the first lower extension and the second lower extension.

Claims

1. A light emitting diode, comprising:

a lower contact layer comprising a first edge, a second edge opposite to the first edge, a third edge connecting the first edge to the second edge, and a fourth edge opposite to the third edge;

a mesa structure arranged on the lower contact layer, the mesa structure comprising an active layer and an upper contact layer;

a first electrode pad arranged on the lower contact layer;

a second electrode pad arranged on the mesa structure;

a first lower extension and a second lower extension extending from the first electrode pad towards the second edge, distal ends of the first lower extension and the second lower extension being farther away from each other than front ends thereof contacting the first electrode pad; and

a first upper extension, a second upper extension, and a third upper extension extending from the second electrode pad,

wherein the first upper extension and the second upper extension extend from the second electrode pad to enclose the first lower extension and the second lower extension, and the third upper extension extends to a region between the first lower extension and the second lower extension, and

wherein the first lower extension and the second lower extension comprise a shape convexly bent towards the third edge and the fourth edge, respectively.

2. The light emitting diode of claim 1, wherein the front ends of the first lower extension and the second lower extension are farther away from the first edge than the center of the first electrode pad.

3. The light emitting diode of claim 2, wherein the first upper extension and the second upper extension comprise a shape convexly bent towards the third edge and the fourth edge, respectively.

4. The light emitting diode of claim 3, wherein the first upper extension and the second upper extension each extend towards the second edge from the second electrode pad and then extend towards the first edge.

5. The light emitting diode of claim 4, wherein distal ends of the first upper extension and the second upper extension are closer to the first edge than front ends of the first lower extension and the second lower extension.

6. The light emitting diode of claim 5, wherein the distal ends of the first upper extension and the second upper extension are disposed on a straight line passing through the center of the first electrode pad, the straight line parallel to the first edge.

7. The light emitting diode of claim 4, wherein the first upper extension and the second upper extension extend to be relatively closer to the third edge and the fourth edge, respectively, and then extend to be relatively farther away from the third edge and the fourth edge, respectively.

8. The light emitting diode of claim 4, wherein front ends of the first upper extension and the second upper extension contacting the second electrode pad extend to a distance from the second edge that is less than a distance from the center of the second electrode pad to the second edge.

9. The light emitting diode of claim 8, wherein the shortest distance between the first upper extension and the second edge is substantially the same as the shortest distance between the second electrode pad and the second edge.

10. The light emitting diode of claim 1, wherein the shortest distance between the first upper extension and each point of the first lower extension is shorter than the shortest distance between the third upper extension and each point of the first lower extension.

11. The light emitting diode of claim 10, wherein the shortest distance between the first upper extension and the distal end of the first lower extension is shorter than the shortest distance between the first upper extension and other points of the first lower extension.

12. The light emitting diode of claim 11, wherein the shortest distance between the first lower extension and a distal end of the third upper extension is shorter than the shortest distance between the first electrode pad and the distal end of the third upper extension.

13. The light emitting diode of claim 1, wherein the mesa structure comprises a symmetrical structure along a straight line passing through the centers of the first electrode pad and the second electrode pad.

14. A light emitting diode, comprising:

a lower contact layer comprising a first edge, a second edge opposite to the first edge, a third edge connecting the first edge to the second edge, and a fourth edge opposite to the third edge;

a mesa structure arranged on the lower contact layer, the mesa structure comprising an active layer and an upper contact layer;

a first electrode pad arranged on the lower contact layer;

a second electrode pad arranged on the mesa structure;

a first lower extension and a second lower extension extending from the first electrode pad towards the second edge, distal ends of the first lower extension and the second lower extension being farther away from each other than front ends thereof contacting the first electrode pad; and

a first upper extension, a second upper extension, and a third upper extension extending from the second electrode pad,

wherein the first upper extension and the second upper extension extend from the second electrode pad to enclose the first lower extension and the second lower extension, and the third upper extension extends to a region between the first lower extension and the second lower extension, and

wherein the first upper extension and the second upper extension each extend towards the second edge from the second electrode pad and then extend towards the first edge.

15. The light emitting diode of claim 14, wherein distal ends of the first upper extension and the second upper extension are closer to the first edge than front ends of the first lower extension and the second lower extension.

16. The light emitting diode of claim 15, wherein the distal ends of the first upper extension and the second upper extension are disposed on a straight line passing through the center of the first electrode pad, the straight line parallel to the first edge.

17. The light emitting diode of claim 14, wherein front ends of the first upper extension and the second upper extension contacting the second electrode pad extend to a distance from the second edge that is less than a distance from the center of the second electrode pad to the second edge.

18. The light emitting diode of claim 17, wherein the shortest distance between the first upper extension and the second edge is substantially the same as the shortest distance between the second electrode pad and the second edge.

19. A light emitting diode, comprising:

a lower contact layer comprising a first edge, a second edge opposite to the first edge, a third edge connecting the first edge to the second edge, and a fourth edge opposite to the third edge;

a mesa structure arranged on the lower contact layer, the mesa structure comprising an active layer and an upper contact layer;

a first electrode pad arranged on the lower contact layer;

a second electrode pad arranged on the mesa structure;

a first lower extension and a second lower extension extending from the first electrode pad towards the second edge, distal ends of the first lower extension and the second lower extension being farther away from each other than front ends thereof contacting the first electrode pad; and

a first upper extension, a second upper extension, and a third upper extension extending from the second electrode pad,

wherein the first upper extension and the second upper extension extend from the second electrode pad to enclose the first lower extension and the second lower extension, and the third upper extension extends to a region between the first lower extension and the second lower extension, and

wherein the first upper extension and the second upper extension extend to be relatively closer to the third edge and the fourth edge, respectively, and then extend to be relatively farther away from the third edge and the fourth edge, respectively.