Light-emitting device

• US 10,056,525 B2
• Filed: 08/31/2017
• Issued: 08/21/2018
• Est. Priority Date: 02/20/2014
• Status: Active Grant

• Current Assignee: Epistar Corporation (Ennostar, Inc.)
• Original Assignee: Epistar Corporation (Ennostar, Inc.)
• Inventors: Chung, Chien-Kai, Chiu, Po-Shun, Wang, Hsin-Ying, Kuo, De-Shan, Ko, Tsun-Kai, Huang, Yu-Ting
• Primary Examiner(s): HO, TU TU V
• Application Number:
  US15/692,759
• Publication Number:
  US 20170365741A1
• Time in Patent Office: 355 Days
• Field of Search: 257 99
• CPC Class Codes: H01L 33/145 with a current-blocking structure
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers
• CPC Class Codes: H01L 33/38 with a particular shape
• CPC Class Codes: H01L 33/382 the electrode extending partially in or entirely through the semiconductor body

Abstract

A light-emitting device includes: a rectangular shape with a 1^st side, a 2^nd side opposite to the 1^st side, and a 3^rd side connecting the 1^st and the 2^nd sides; a first electrode pad formed adjacent to the 3^rd side; a second electrode pad formed adjacent to the 2^nd side; a first extension electrode, extending from the first electrode pad in a direction away from the 3^rd side and bended toward the 2^nd side; and a second extension electrode, including a first and a second branches respectively extending from the second electrode pad; wherein a distance between the first electrode pad and the 3^rd side is smaller than a distance between the second electrode pad and the 3^rd side; wherein an end portion of the first branch includes a first arc bending to the 3^rd side and a minimum distance between the first branch and the 1^st side is smaller than a minimum distance between the second branch and the 1^st side.

Claims

1. A light-emitting device, comprising:

a rectangular shape with a first side, a second side opposite to the first side, and a third side connecting the first side and the second side;

a first electrode pad formed adjacent to the third side;

a second electrode pad formed adjacent to the second side;

a first extension electrode, extending from the first electrode pad in a direction away from the third side and bended toward the second side; and

a second extension electrode, comprising a first branch and a second branch respectively extended from the second electrode pad;

wherein a distance between the first electrode pad and the third side is smaller than a distance between the second electrode pad and the third side;

wherein an end portion of the first branch comprises a first arc bending to the third side and a minimum distance between the first branch and the first side is smaller than a minimum distance between the second branch and the first side.

2. The light-emitting device according to claim 1, further comprising a substrate and a light-emitting structure formed on the substrate;

wherein the light-emitting structure comprises a lower semiconductor layer, an active layer, and an upper semiconductor layer;

wherein the first extension electrode is formed on the lower semiconductor layer and the second extension electrode is formed on the upper semiconductor layer.

3. The light-emitting device according to claim 2, further comprising a transparent conductive layer formed on the upper semiconductor layer.

4. The light-emitting device according to claim 1, further comprising a current blocking layer under the first electrode pad.

5. The light-emitting device according to claim 1, wherein the first branch comprises a stripe between the second electrode pad and the first arc and is parallel with the third side.

6. The light-emitting device according to claim 1, wherein the second branch comprises a second arc connecting the second electrode pad and a stripe connecting to the arc, and the stripe is parallel with the third side.

7. The light-emitting device according to claim 1, wherein the first extension electrode comprises a stripe parallel to the third side.

8. The light-emitting device according to claim 2, wherein the second electrode pad is located near one corner of the substrate.

9. The light-emitting device according to claim 8, wherein the first electrode pad and the second electrode pad are located on the substrate in a diagonal direction.

10. A light-emitting device, comprising:

a light-emitting stack comprising a rectangular shape with a first side, a second side opposite to the first side, a third side connecting the first side and the second side, and a fourth side opposite to the third side;

a transparent conductive layer, formed on the light-emitting stack;

a mesa formed in the light-emitting stack, adjacent to the third side;

a first electrode formed on the mesa, comprising a first stripe and a bending portion, wherein the first electrode is elongated from the third side in a direction away from the third side and bends toward the second side, and the bending portion is between the first stripe and the third side;

a second electrode formed on the light-emitting stack, comprising;

a second electrode pad adjacent to the second side;

a first branch and a second branch formed on the transparent conductive layer, and respectively extending from the second electrode pad,

wherein an end portion of the first branch bends to the third side and a minimum distance between the first branch and the first side is smaller than a minimum distance between the second branch and the first side.

11. The light-emitting device according to claim 10, wherein the light-emitting stack comprises a n-type semiconductor layer, an active layer, and a p-type semiconductor layer;

wherein the mesa is a top surface of the n-type semiconductor layer not covered by the active layer and the p-type semiconductor layer.

12. The light-emitting device according to claim 10, further comprising a current blocking layer under the second electrode pad.

13. The light-emitting device according to claim 10, further comprising a current blocking layer under the first electrode.

14. The light-emitting device according to claim 10, further comprising an imaginary line connecting a distal end of the first branch to a distal end of the second branch, and wherein the bending portion of the first electrode is located between the second electrode pad and the imaginary line.

15. The light-emitting device according to claim 10, wherein the first stripe of the first electrode is parallel with the third side.

16. The light-emitting device according to claim 10, wherein the first stripe is located between the first branch and the second branch.

17. The light-emitting device according to claim 10, wherein the second branch comprises an arc connecting to the second electrode pad and a second stripe connecting to the arc, and the second stripe is parallel with the first stripe.