Light emitting device

• US 9,893,024 B2
• Filed: 10/02/2015
• Issued: 02/13/2018
• Est. Priority Date: 08/30/2010
• Status: Active Grant

• Current Assignee: Epistar Corporation (Ennostar, Inc.)
• Original Assignee: Epistar Corporation (Ennostar, Inc.)
• Inventors: Chen, Chao Hsing, Shen, Chien Fu, Ko, Tsun Kai, Hon, Schang Jing, Liu, Hsin Mao
• Primary Examiner(s): Fan, Bo
• Application Number:
  US14/874,063
• Publication Number:
  US 20160027745A1
• Time in Patent Office: 865 Days
• Field of Search: 257 88, 36224906
• CPC Class Codes: H01L 23/60 Protection against electrostatic charges or discharges, e.g. Faraday shields
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 27/153 in a repetitive configuration, e.g. LED bars
• CPC Class Codes: H01L 27/156 two-dimensional arrays
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• 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
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Abstract

The present disclosure provides a light emitting device including a serially-connected LED array comprising a plurality of LED cells on a substrate. The serially-connected LED array includes a first LED cell, a second LED cell, and a serially-connected LED sub-array comprising at least three LED cells intervening between the first and second LED cell; and a plurality of conducting metals formed on the LED cells to electrically connect the plurality of LED cell in series; wherein among the LED sub-array which are continuously and sequentially connected by the conducting metals, each LED cell connects to a previous LED cell by a first connecting direction and connects to a next LED cell by a second connecting direction, the first connecting direction is not parallel to the second connecting direction.

Claims

1. A light emitting device, comprising:

a single substrate;

a serially-connected LED array, comprising;

a plurality of LED cells, comprising a first LED cell, a second LED cell, a third LED cell, a fourth LED cell, a fifth LED cell, and a sixth LED cell serially-connected sequentially on the single substrate;

wherein the first LED cell, the fourth LED cell, and the fifth LED cell are arranged in a first column;

wherein the second LED cell, the third LED cell, and the sixth LED cell are arranged in a second column;

wherein each of the plurality of LED cells comprises a first pair and a second pair of parallel edges; and

wherein the first pairs of parallel edges are not parallel to the second pairs of parallel edges;

a trench between each adjacent two LED cells; and

a plurality of conducting metals comprising a first conducting metal, a second conducting metal, a third conducting metal, a fourth conducting metal, and a fifth conducting metal formed on the plurality of LED cells to electrically connect the LED cells in series;

wherein each of the conducting metals comprises a middle part formed on the trench and two extending parts respectively formed on one LED cell and an adjacent LED cell;

wherein the first LED cell connects to the second LED cell with the first conducting metal inbetween, and the middle part of the first conducting metal is formed between one edge of the first pair of parallel edges of the first LED cell and one edge of the first pair of parallel edges of the second LED cell;

the second LED cell connects to the third LED cell with the second conducting metal inbetween, and the middle part of the second conducting metal is formed between one edge of the second pair of parallel edges of the second LED cell and one edge of the second pair of parallel edges of the third LED cell;

the third LED cell connects to the fourth LED cell with the third conducting metal inbetween, and the middle part of the third conducting metal is formed between one edge of the first pair of parallel edges of the third LED cell and one edge of the first pair of parallel edges of the fourth LED cell;

the fourth LED cell connects to the fifth LED cell with the fourth conducting metal inbetween, and the middle part of the fourth conducting metal is formed between one edge of the second pair of parallel edges of the fourth LED cell and one edge of the second pair of parallel edges of the fifth LED cell;

the fifth LED cell connects to the sixth LED cell with the fifth conducting metal inbetween, and the middle part of the fifth conducting metal is formed between one edge of the first pair of parallel edges of the fifth LED cell and one edge of the first pair of parallel edges of the sixth LED cell.

2. The light emitting device as claimed in claim 1, wherein the serially-connected LED array further comprises an initial LED cell and a last LED cell.

3. The light emitting device as claimed in claim 2, wherein the initial LED cell and the last LED cell are arranged in different columns.

4. The light emitting device as claimed in claim 1, wherein each LED cell comprises a first semiconductor layer, an active layer and a second semiconductor layer sequentially formed on the single substrate.

5. The light emitting device as claimed in claim 4, wherein the first semiconductor layer and/or the second semiconductor layer comprises a round corner with a radius of the curvature not less than 15 μ

m.

6. The light emitting device as claimed in claim 4, wherein the distance between the first semiconductor layer of the first LED cell and the first semiconductor layer of the second LED cell is larger than 15 μ

m and smaller than 50 μ

m.

7. The light emitting device as claimed in claim 4, wherein the first semiconductor layer of the one LED cell in the serially-connected LED array is electrically connected to the second semiconductor layer of the adjacent LED cell in the serially-connected LED array.

8. The light emitting device as claimed in claim 1, wherein at least one of the extending parts comprises an enlarged terminal.

9. The light emitting device as claimed in claim 1, wherein the single substrate is a single crystalline substrate, and the plurality of LED cells of the series-connected LED array is epitaxially grown on the single crystalline substrate.

11. The light emitting device as claimed in claim 4, wherein the two extending parts of each of the conducting metals are formed on the first semiconductor layer of one LED cell and the second semiconductor layer of an adjacent LED cell respectively.

12. The light emitting device as claimed in claim 2, further comprising a first bonding pad and a second bonding pad;

wherein each LED cell comprises a first semiconductor layer, an active layer and a second semiconductor layer sequentially formed on the single substrate, wherein the first bonding pad is formed on the second semiconductor layer of the initial LED cell, and the second bonding pad is formed on the first semiconductor layer of the last cell.

10. A light emitting device, comprising:

a single substrate;

a plurality of LED cells arranged in an array with a first column and a second column on the substrate;

a plurality of trench areas between each adjacent two LED cells; and

a plurality of conducting metals formed on the LED cells to electrically connect the plurality of LED cell in series;

wherein each conducting metal comprises;

a middle part formed on the trench areas with an extending direction; and

a first extending part and a second extending part respectively formed on one LED cell and an adjacent LED cell;

wherein each LED cell comprises a first semiconductor layer, an active layer and a second semiconductor layer sequentially formed on the substrate;

wherein the plurality of LED cells comprises N LED cells, wherein the N LED cells are continuously and sequentially connected by the conducting metals, wherein N≧

6 and the extending directions of the middle parts change N−

2 times; and

wherein each two of the plurality of LED cells adjoining to each other are electrically connected to each other with less than three LED cells inbetween.

13. The light emitting device as claimed in claim 10, wherein the first extending and the second extending part are not parallel.

14. The light emitting device as claimed in claim 10, further comprising:

a current blocking layer formed under the conducting metal; and

a transparent conducting layer formed on the current blocking layer.

15. The light emitting device as claimed in claim 10, further comprising:

a first bonding pad and a second bonding pad;

wherein the plurality of LED cells comprises a first LED cell, a second LED cell, a third LED cell, and a Nth LED cell, the first bonding pad is formed on the first LED cell, the second bonding pad is formed on the Nth LED cell, the first LED cell and the second LED cell are connected by one of the plurality of conducting metals comprising the middle part with a first extending direction;

the second LED cell and the third LED cell are connected by another one of the plurality of conducting metals comprising the middle part with a second extending direction, the first extending direction and the second extending direction are different.

16. The light emitting device as claimed in claim 10, wherein the first bonding pad arranged in the first column, and the second bonding pad arranged in the second column.

17. The light emitting device as claimed in claim 10, wherein each four LED cells of the plurality of LED cells adjacent to each other and arranged in the first column and the second column comprises four trench areas inbetween, and three middle parts formed on three of the four trench areas respectively.