LIGHT EMITTING DEVICE HAVING LIGHT EMITTING ELEMENTS

• US 20090108275A1
• Filed: 01/12/2009
• Published: 04/30/2009
• Est. Priority Date: 08/29/2002
• Status: Active Grant

• Current Assignee: Seoul Semiconductor Co., Ltd.
• Original Assignee: Seoul Semiconductor Co., Ltd.
• Inventors: Ao, Jin-Ping, Ono, Yasuo, Sakai, Shiro
• Granted Patent: US 8,084,774 B2
• Time in Patent Office: Days
• US Class Current: 257/88
• CPC Class Codes: H01L 2224/24 of an individual high density interconnect connector
• CPC Class Codes: H01L 27/15 including semiconductor components having potential barriers, specially adapted for light emission
• 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 33/08 with a plurality of light emitting regions, e.g. laterally discontinuous light emitting layer or photoluminescent region integrated within the semiconductor body H01L27/15 takes precedence
• 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 device operating on a high drive voltage and a small drive current. LEDs (1) are two-dimensionally formed on an insulating substrate (10) of e.g., sapphire monolithically and connected in series to form an LED array. Two such LED arrays are connected to electrodes (32) in inverse parallel. Air-bridge wiring (28) is formed between the LEDs (1) and between the LEDs (1) and electrodes (32). The LED arrays are arranged zigzag to form a plurality of LEDs (1) to produce a high drive voltage and a small drive current. Two LED arrays are connected in inverse parallel, and therefore an AC power supply can be used as the power supply.

Claims

1. A light emitting device, comprising:

a single insulating substrate;

a first array of GaN-based light emitting elements on the single insulating substrate, the first array of light emitting elements comprising a first set of light emitting elements and a second set of light emitting elements, each set comprising at least one light emitting element,

wherein the light emitting elements of the first array are connected in series with each other between a first electrode pad and a second electrode pad, and the first set of light emitting elements and the second set of light emitting elements are disposed facing opposite directions from each other.

2. The light emitting device of claim 1, wherein the first array of light emitting elements further comprises a third set of light emitting elements, the third set of light emitting elements being disposed facing a direction opposite that of the second set of light emitting elements.

3. The light emitting device of claim 2, wherein the second set of light emitting elements is disposed between the first set of light emitting elements and the third set of light emitting elements.

4. The light emitting device of claim 3, wherein the first electrode pad and the second electrode pad are disposed on the single insulating substrate, the first electrode pad being connected to a light emitting element of the first set of light emitting elements and the second electrode pad being connected to a light emitting element of the third set of light emitting elements.

5. The light emitting device of claim 1, further comprising a second array of GaN-based light emitting elements, the second array of light emitting elements being connected in parallel with the first array of light emitting elements so that the first array and the second array are of opposite polarities from each other,

wherein the second array of light emitting elements comprises a third set of light emitting elements and a fourth set of light emitting elements, each set comprising at least one light emitting element, and

wherein the light emitting elements of the second array are connected in series with each other between the first electrode pad and the second electrode pad, and the third set of light emitting elements and the fourth set of light emitting elements are disposed facing opposite directions from each other.

6. The light emitting device of claim 2, further comprising a second array of GaN-based light emitting elements, the second array of light emitting elements being connected in parallel with the first array of light emitting elements so that the first array and the second array are of opposite polarities from each other,

wherein the second array of light emitting elements comprises a fourth set of light emitting elements, a fifth set of light emitting elements, and a sixth set of light emitting elements, each set comprising at least one light emitting element,

wherein the light emitting elements of the second array are connected in series with each other between the first electrode pad and the second electrode pad, and the fourth set of light emitting elements and the fifth set of light emitting elements are disposed facing opposite directions from each other, and the fifth set of light emitting elements and the sixth set of light emitting elements are disposed facing opposite directions from each other.

7. The light emitting device of claim 6, wherein the fifth set of light emitting elements is disposed between the fourth set of light emitting elements and the sixth set of light emitting elements.

8. The light emitting device of claim 7, wherein the first electrode pad and the second electrode pad are disposed on the single insulating substrate, the first electrode pad being connected to a light emitting element of the first set of light emitting elements and a light emitting element of the fourth set of light emitting elements, and the second electrode pad being connected to a light emitting element of the third set of light emitting elements and a light emitting element of the sixth set of light emitting elements.

9. The light emitting device of claim 8, wherein:

the fourth set of light emitting elements is disposed between the first set of light emitting elements and the second set of light emitting elements,

the second set of light emitting elements is disposed between the fourth set of light emitting elements and the fifth set of light emitting elements,

the fifth set of light emitting elements is disposed between the second set of light emitting elements and the third set of light emitting elements, and

the third set of light emitting elements is disposed between the fifth set of light emitting elements and the sixth set of light emitting elements.

10. The light emitting device of claim 6, wherein the single insulating substrate comprises four corners, and the first electrode pad and the second electrode pad are disposed at diagonally opposite corners of the single insulating substrate from each other.

11. The light emitting device of claim 5, wherein the single insulating substrate comprises four corners, and the first electrode pad and the second electrode pad are disposed at a first corner and a second corner, respectively, of the single insulating substrate.

12. The light emitting device of claim 5, wherein a light emitting element of the first set of light emitting elements and a light emitting element of the third set of light emitting elements have a common n electrode, and a light emitting element of the second set of light emitting elements and a light emitting element of the fourth set of light emitting elements have a common n electrode.

13. The light emitting device of claim 6, wherein a light emitting element of the first set of light emitting elements and a light emitting element of the fourth set of light emitting elements have a common n electrode, a light emitting element of the second set of light emitting elements and a light emitting element of the fifth set of light emitting elements have a common n electrode, and a light emitting element of the third set of light emitting elements and a light emitting element of the sixth set of light emitting elements have a common n electrode.

14. The light emitting device of claim 1, wherein the first array of light emitting elements are connected to each other by air bridge lines.

15. The light emitting device of claim 6, wherein the first array of light emitting elements are connected to each other by air bridge lines, and the second array of light emitting elements are connected to each other by air bridge lines.

16. The light emitting device of claim 6, wherein the first array of light emitting elements, the second array of light emitting elements, the first electrode pad, and the second electrode pad together form a square shape.