Light emitting device and the manufacture method thereof

• US 8,067,780 B2
• Filed: 09/05/2007
• Issued: 11/29/2011
• 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): Nguyen; Cuong Q
• Assistant Examiner(s): TRAN, TRANG Q
• Application Number:
  US11/896,661
• Publication Number:
  US 20080054290A1
• Time in Patent Office: 1,546 Days
• Field of Search: 257/79, 257 94- 99, 257/103, 257/E33.065
• 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 light-emitting element for bonding to a submount, the light-emitting element comprising:

a transparent substrate;

a first electricity semiconductor layer formed on the transparent substrate;

an active layer formed on the first electricity semiconductor layer to receive a forward voltage to emit light;

a second electricity semiconductor layer formed on the active layer, comprising an uneven surface shape;

a contact layer formed on the second electricity semiconductor layer, said contact layer having an uneven surface shape conforming to the uneven surface shape of the second electricity semiconductor layer and forming ohmic contact therebetween;

an electrode formed on the contact layer, said electrode having an uneven surface shape conforming to the uneven surface shape of the contact layer to make the surfaces of the electrode have a plurality of micro-bumps to bond the light-emitting element to a submount via the plurality of micro-bumps, wherein the plurality of micro-bumps provides a plurality of current channels.

2. The light-emitting element according to claim 1, wherein thickness of the plurality of micro-bumps is between 0.3 um and 20 um.

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

4. The light-emitting element according to claim 1, wherein the shape of the plurality of micro-bumps is selected form the group consisting of a circle, a rectangle, a polygon, and the combination thereof.

5. The light-emitting element according to claim 4, wherein diameter of the plurality of circular micro-bumps is between 1 um and 250 um.

6. The light-emitting element according to claim 4, wherein length of short sides of the plurality of rectangular micro-bumps is between 1 um and 250 um.

7. The light-emitting element according to claim 1 further comprising a submount bonded to the plurality of micro-bumps of the electrode by a direct bonding method.

8. The light-emitting element according to claim 7, wherein the direct bonding method is thermosonic bonding.

9. The light-emitting element according to claim 7, wherein the submount comprises a printed circuit board.