Light emitting device and the manufacture method thereof

• US 8,664,686 B2
• Filed: 10/25/2011
• Issued: 03/04/2014
• Est. Priority Date: 09/05/2006
• Status: Active Grant

• Current Assignee: Epistar Corporation
• Original Assignee: Epistar Corporation
• Inventors: Shieh, Yuh-Ren, Fan, Hsuan-Cheng, Lin, Jin-Ywan, Hsu, Cheng-Yi, Huang, Chung-Kuei
• Primary Examiner(s): MENZ, DOUGLAS M
• Application Number:
  US13/281,136
• Publication Number:
  US 20120040480A1
• Time in Patent Office: 861 Days
• Field of Search: 257/99, 257/98
• US Class Current: 257/99
• CPC Class Codes: H01L 2224/05001 Internal layers
• CPC Class Codes: H01L 2224/05023 the whole internal layer protruding from the surface
• CPC Class Codes: H01L 2224/05099 Material
• CPC Class Codes: H01L 2224/05557 comprising protrusions or indentations
• CPC Class Codes: H01L 2224/05568 the whole external layer protruding from the surface
• CPC Class Codes: H01L 2224/05573 Single external layer
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/08238 the bonding area connecting to a bonding area protruding from the surface of the item
• CPC Class Codes: H01L 2224/16 of an individual bump connector
• CPC Class Codes: H01L 24/05 of an individual bonding area
• CPC Class Codes: H01L 24/08 of an individual bonding area
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2933/0016 relating to electrodes
• 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 33/62 Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls

Abstract

This invention provides a light-emitting element and the manufacture method thereof. The light-emitting element is suitable for flip-chip bonding and comprises an electrode having a plurality of micro-bumps for direct bonding to a submount. Bonding within a relatively short distance between the light-emitting device and the submount can be formed so as to improve the heat dissipation efficiency of the light-emitting device.

Claims

1. A method of manufacturing a light-emitting element comprising the steps of:

providing an LED comprising a transparent substrate and an electrode; and

etching only a portion of the depth of the electrode thereby monolithically forming a plurality of micro-bumps for providing a plurality of current channels;

providing a submount; and

flip-chip bonding the electrode having the plurality of micro-bumps to the submount.

2. The method according to claim 1, wherein the method of flip-chip bonding comprises direct flip-chip bonding.

3. The method according to claim 2, wherein the method of direct flip-chip bonding comprises thermosonic bonding.

4. The method according to claim 1, wherein a thickness of the plurality of micro-bumps is between 0.3 um and 20 um.

5. The method according to claim 1, wherein ratio of summation of surface areas of the micro-bumps to that of the electrode is between 5% and 50%.

6. The method according to claim 1, wherein the shape of the plurality of micro-bumps is selected from the group consisting of a circle, a rectangle, a polygon, and the combination thereof.

7. The method according to claim 6, wherein diameter of the plurality of circular micro-bumps is between 1 um and 250 um.

8. The method according to claim 6, wherein length of short sides of the plurality of rectangular micro-bumps is between 1 um and 250 um.

9. The method according to claim 1, wherein the material of the plurality of micro-bumps is selected from the group consisting of Au, Ag, Al, and Cu.

10. The method according to claim 1, wherein the submount comprises a printed circuit board.

11. The method according to claim 1, wherein providing the LED further comprises the steps of:

forming a first electricity semiconductor layer on the transparent substrate;

forming an active layer on the first electricity semiconductor layer; and

forming a second electricity semiconductor layer formed on the active layer.

12. The method according to claim 11, Wherein providing the LED further comprises the steps of:

forming a contact layer on the second electricity semiconductor layer, and

forming the electrode on the contact layer.

13. The method according to claim 1, wherein the plurality of micro-bumps are separated from each other.

14. The method according to claim 1, wherein the electrode is formed by lithography and etching process.

15. The method according to claim 1, wherein the plurality of current channels is formed between the LED and the submount.

16. The method according to claim 11, wherein the plurality of micro-bumps is formed on the second electricity semiconductor layer.

17. The method according to claim 1, wherein there is not any bonding bump on the submount during flip-chip bonding the electrode having the plurality of micro-bumps to the submount.

18. The method according to claim 1, wherein the plurality of micro-bumps forms an outmost boundary of the LED.