LATERAL THERMAL DISSIPATION LED AND FABRICATION METHOD THEREOF

• US 20100224858A1
• Filed: 03/04/2010
• Published: 09/09/2010
• Est. Priority Date: 03/06/2009
• Status: Active Grant

• Current Assignee: Advanced Optoelectronic Technology, Inc.
• Original Assignee: Advanced Optoelectronic Technology, Inc.
• Inventors: TU, PO MIN, YEH, YING CHAO, LIN, WEN YU, WU, PENG YI, CHAN, SHIH HSIUNG, HUANG, SHIH CHENG
• Granted Patent: US 8,513,696 B2
• Time in Patent Office: Days
• US Class Current: 257/13
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48257 connecting the wire to a die pad of the item
• CPC Class Codes: H01L 2224/49107 on the semiconductor or solid-state body
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• 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 2924/181 Encapsulation
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating
• CPC Class Codes: H01L 33/642 characterized by the shape

Abstract

A lateral thermal dissipation LED and a fabrication method thereof are provided. The lateral thermal dissipation LED utilizes a patterned metal layer and a lateral heat spreading layer to transfer heat out of the LED. The thermal dissipation efficiency of the LED is increased, and the lighting emitting efficiency is accordingly improved.

Claims

1. A lateral thermal dissipation LED, comprising:

a substrate;

an N type conductive semiconductor layer disposed on the substrate;

a light emitting layer disposed on the N type conductive semiconductor layer;

a P type conductive semiconductor layer disposed on the light emitting layer; and

a heat spreading layer connecting the N type conductive semiconductor layer to a package substrate.

2. The lateral thermal dissipation LED of claim 1, wherein the light emitting layer is a single quantum well layer or a multiple quantum well layer.

3. The lateral thermal dissipation LED of claim 1, wherein the heat spreading layer is made by mixing silver and epoxy.

4. The lateral thermal dissipation LED of claim 1, further comprising a buffer layer interposed between the substrate and the N type conductive semiconductor layer.

5. The lateral thermal dissipation LED of claim 4, further comprising an undoped semiconductor layer interposed between the buffer layer and the N type conductive semiconductor layer.

6. The lateral thermal dissipation LED of claim 5, further comprising a metal layer with a pattern disposed on the undoped semiconductor layer, wherein the pattern of the metal layer includes a plurality of holes, and the metal layer with the pattern and the N type conductive semiconductor layer have ohmic contact resistance.

7. The lateral thermal dissipation LED of claim 6, wherein the heat spreading layer connects the N type conductive semiconductor layer and the package substrate.

8. The lateral thermal dissipation LED of claim 1, wherein portions of the P type conductive semiconductor layer, the light emitting layer and the N type conductive semiconductor layer are removed to expose a portion of the N type conductive semiconductor layer.

9. The lateral thermal dissipation LED of claim 8, further comprising a P type electrode and an N type electrode, wherein the P electrode is disposed on the P type conductive semiconductor layer, and the N type electrode is disposed on the exposed portion of the N type conductive semiconductor layer.

10. The lateral thermal dissipation LED of claim 9, further comprising a protecting layer covering the N type conductive semiconductor layer and the P type conductive semiconductor layer, wherein the N type electrode and the P type electrode are not covered with the protecting layer.

11. A method for manufacturing a lateral thermal dissipation LED, comprising steps of:

providing a substrate;

forming an N type conductive semiconductor layer on the substrate;

forming a light emitting layer on the N type conductive semiconductor layer;

forming a P type conductive semiconductor layer on the light emitting layer; and

forming a heat spreading layer on the N type conductive semiconductor layer.

12. The method of claim 11, wherein the lateral thermal dissipation LED is a Group III-V nitride LED or a Group II-VI nitride LED, and the light emitting layer is a single quantum well layer or a multiple quantum well layer.

13. The method of claim 11, wherein the heat spreading layer is made by mixing silver and epoxy.

14. The method of claim 11, further comprising a step of forming a buffer layer between the substrate and the N type conductive semiconductor layer.

15. The method of claim 14, further comprising a step of forming an undoped semiconductor layer between the buffer layer and the N type conductive semiconductor layer.

16. The method of claim 15, further comprising a step of forming a metal layer with a pattern on the undoped semiconductor layer, wherein the pattern of the metal layer includes a plurality of holes, and the material of the metal layer is chromium or tungsten.

17. The method of claim 16, wherein the pattern of the metal layer is formed on the undoped semiconductor layer by photolithography and etching after evaporation or sputtering.

18. The method of claim 11, wherein portions of the P type conductive semiconductor layer, the light emitting layer and the N type conductive semiconductor layer are removed by photolithography and etching to expose a portion of N type conductive semiconductor layer.

19. The method of claim 18, further comprising a P type electrode and an N type electrode, wherein the P electrode is disposed on the P type conductive semiconductor layer, and the N type electrode is disposed on the exposed portion of the N type conductive semiconductor layer.

20. The method of claim 19, further comprising a step of forming a protecting layer on the N type conductive semiconductor layer and the P type conductive semiconductor layer, wherein the N type electrode and the P type electrode the protecting layer are not covered with the protecting layer, the material of the protecting layer is SiO₂, Si₃N₄, or SiON, and the protecting layer is formed by chemical vapor deposition (CVD) or plasma enhanced chemical vapor deposition (PECVD).