LIGHT EMITTING DIODE

• US 20170069789A1
• Filed: 11/17/2016
• Published: 03/09/2017
• Est. Priority Date: 03/27/2015
• Status: Active Grant

• Current Assignee: Seoul Viosys Co., Ltd. (Seoul Semiconductor Co., Ltd.)
• Original Assignee: Seoul Viosys Co., Ltd. (Seoul Semiconductor Co., Ltd.)
• Inventors: Ryu, Yong Woo, Kim, Mae Yi, Lee, Jin Woong, Yoon, Yeo Jin, Lee, Seom Geun, Lee, Keum Ju
• Granted Patent: US 9,905,729 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 33/32 containing nitrogen
• CPC Class Codes: H01L 33/38 with a particular shape
• CPC Class Codes: H01L 33/42 Transparent materials
• CPC Class Codes: H01L 33/62 Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls

Abstract

A light emitting diode is provided to comprises: a substrate that has an elongated rectangular shape in one direction; a light emitting structure positioned on the substrate and having an opening for exposing a first conductive semiconductor layer; a first electrode pad disposed to be closer to a first corner of the substrate; a second electrode pad disposed to be relatively closer to a second corner of the substrate opposing to the first corner; a first extension extending from the first electrode pad; and a second extension and a third extension extending from the second electrode pad to sides of the first extension, wherein an imaginary line connecting an end of the second extension and an end of the third extension is located between the first electrode pad and the first corner.

Claims

1. A light emitting diode comprising:

a substrate having a rectangular shape elongated in one direction;

a light emitting structure comprising a first conductive type semiconductor layer disposed on the substrate, a second conductive type semiconductor layer disposed on the first conductive type semiconductor layer, and an active layer interposed between the first conductive type semiconductor layer and the second conductive type semiconductor layer, the light emitting structure having an opening formed through the second conductive type semiconductor layer and the active layer to expose the first conductive type semiconductor layer;

a first electrode pad disposed on the first conductive type semiconductor layer in the opening to be closer to a first corner of the substrate than other corners thereof;

a second electrode pad disposed on the second conductive type semiconductor layer to be relatively close to a second corner of the substrate that faces the first corner;

a first extension extending from the first electrode pad; and

a second extension and a third extension extending from the second electrode pad to both sides of the first extension,

wherein an imaginary line connecting a distal end of the second extension to a distal end of the third extension is placed between the first electrode pad and the first corner.

2. The light emitting diode according to claim 1, wherein

a center of the first electrode pad is spaced apart from a longitudinal central axis of the light emitting structure, and

a distance from the center of the first electrode pad to the longitudinal central axis is smaller than a diameter of the first electrode pad and greater than or equal to a radius thereof.

3. The light emitting diode according to claim 2, wherein

the first extension comprises a curved section and a linear section,

the curved section connecting the first electrode pad to the linear section,

the linear section of the first extension being placed on the longitudinal central axis of the light emitting structure,

the curved section of the first extension gradually approaching a transversal central axis of the light emitting structure with increasing distance from the first electrode pad.

4. The light emitting diode according to claim 3, wherein

the linear section of the first extension extends towards an upper edge of the light emitting structure, and

a distance from a distal end of the linear section of the first extension to the upper edge of the light emitting structure is smaller than or equal to a distance from the linear section of the first extension to opposite edges of the light emitting structure.

5. The light emitting diode according to claim 4, wherein the shortest distance from the linear section of the first extension to the second extension is the same as the shortest distance from the linear section of the first extension to the third extension.

6. The light emitting diode according to claim 1, wherein

the second extension comprises a first curved section, a linear section and a second curved section sequentially formed from the second electrode pad,

the first curved section of the second extension has a predetermined curvature and extends from the second electrode pad so as to be gradually spaced apart from the longitudinal central axis of the light emitting structure,

the linear section of the second extension is parallel to the linear section of the first extension, and

the second curved section of the third extension intersects the longitudinal central axis of the light emitting structure.

7. The light emitting diode according to claim 6, wherein

the third extension comprises a first curved section, a first linear section, a second curved section, a second linear section and a third curved section sequentially formed from the second electrode pad,

the first curved section extends from the second electrode pad so as to be spaced apart from the transversal central axis of the light emitting structure,

the first linear section is parallel to the transversal central axis of the light emitting structure and intersects the longitudinal central axis of the light emitting structure,

the second curved section has the same curvature as the first curved section and extends from the first linear section so as to approach the transversal central axis,

the second linear section is parallel to the linear section of the first extension, and

the third curved section is curved so as to be spaced apart from the transversal central axis and the longitudinal central axis of the light emitting structure.

8. The light emitting diode according to claim 6, wherein

the first extension comprises a curved section extending from the first electrode pad and a linear section extending from the curved section, and

the shortest distance from the linear section of the first extension to the linear section of the second extension is the same as the shortest distance from the linear section of the first extension to the second linear section of the third extension.

9. The light emitting diode according to claim 1, further comprising:

a transparent electrode layer covering the light emitting structure,

wherein the second electrode pad, the second extension and third extension are disposed on the transparent electrode layer.

10. The light emitting diode according to claim 9, further comprising:

a current blocking layer disposed between the transparent electrode layer and the light emitting structure under the second electrode pad, the second extension and the third extension.

11. A light emitting diode comprising:

a substrate;

two or more light emitting cells disposed parallel to each other on the substrate and having an elongated rectangular shape;

a first electrode pad disposed on a light emitting cell;

a second electrode pad disposed on another light emitting cell;

first, second and third extensions disposed on each of the light emitting cells; and

a connector(s) connecting the light emitting cells to each other,

wherein each of the light emitting cells comprises a first conductive type semiconductor layer, a second conductive type semiconductor layer disposed on the first conductive type semiconductor layer, and an active layer interposed between the first conductive type semiconductor layer and the second conductive type semiconductor layer, and has an opening formed through the second conductive type semiconductor layer and the active layer to expose the first conductive type semiconductor layer, and

wherein the first extension formed on each of the light emitting cells comprises an extension elongated in a longitudinal direction of the light emitting cell and is connected to the first conductive type semiconductor layer in the opening of each of the light emitting cells,

the second extension and the third extension formed on each of the light emitting cells are electrically connected to the second conductive type semiconductor layer of the corresponding light emitting cell and extend from the second electrode pad or the connector to be disposed at both sides of the first extension, and

the connector connects the first extension of a light emitting cell to the second and third extensions of an adjacent light emitting cell,

the connector(s) being disposed near corners of the light emitting cells that face the first electrode pad, the second electrode pad, or other connector in a diagonal direction.

12. The light emitting diode according to claim 11, wherein

each of the first extensions comprises a curved section and a linear section,

each of the curved sections connecting the first electrode pad or the connector to the linear section,

the linear section extending in the longitudinal direction of the light emitting cell.

13. The light emitting diode according to claim 12, wherein

the linear sections of the first extensions are placed on longitudinal central axes of the light emitting cells, respectively, and

the curved sections of the first extensions gradually approach a transversal central axis of the substrate with increasing distance from the first electrode pad or the connector.

14. The light emitting diode according to claim 13, wherein the shortest distance from the linear section of the first extension to the second extension is the same as the shortest distance from the linear section of the first extension to the third extension.

15. The light emitting diode according to claim 14, wherein

a distance from a distal end of the first extension to a point of the third extension placed on the longitudinal central axis of each of the light emitting cells is the same as the shortest distance from the linear section of the first extension to the second extension or the third extension, and

a distance from the distal end of the first extension to the curved section of the third extension is greater than the shortest distance.

16. The light emitting diode according to claim 15, wherein the point of the third extension placed on the longitudinal central axis is placed on the linear section.

17. The light emitting diode according to claim 11, wherein the connectors comprise a linear section inclined with respect to a minor axis direction of the light emitting cells.

18. The light emitting diode according to claim 11, further comprising:

a transparent electrode layer covering each of the light emitting cells,

wherein the second electrode pad, the second extensions and the third extensions are disposed on the transparent electrode layer.

19. The light emitting diode according to claim 18, further comprising:

a current blocking layer disposed between the transparent electrode layer and the light emitting cells under the second electrode pad, the second extension and the third extension.

20. The light emitting diode according to claim 18, wherein

the transparent electrode layer disposed under the second electrode pad comprises an opening, and

a portion of the second electrode pad contacts the second conductive type semiconductor layer or the current blocking layer through the opening.