Light emitting diode with integrated heat dissipater

• US 20040052077A1
• Filed: 08/14/2003
• Published: 03/18/2004
• Est. Priority Date: 09/25/2001
• Status: Abandoned Application

• Current Assignee: Kelvin Shih
• Original Assignee: Kelvin Shih
• Inventors: Shih, Kelvin
• Application Number:
  US10/641,759
• Publication Number:
  US 20040052077A1
• Time in Patent Office: Days
• US Class Current: 362/294
• CPC Class Codes: H01L 2224/48091 Arched
• 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 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: H01L 33/647 the elements conducting electric current to or from the semiconductor body
• CPC Class Codes: H05K 1/021 Components thermally connected to metal substrates or heat-sinks by insert mounting
• CPC Class Codes: H05K 1/182 associated with components mounted in the printed circuit board, e.g. insert mounted components [IMC]
• CPC Class Codes: H05K 2201/10106 Light emitting diode [LED]
• CPC Class Codes: H05K 2201/10659 Different types of terminals for the same component, e.g. solder balls combined with leads

Abstract

A light emitting diode (LED)has an integrated heat sink structure for removing heat from an LED junction and for dissipating heat from the junction to the ambient air. The anode and the cathode both either act as or are coupled to a thermally conductive material which acts as the heat sink. In one embodiment, the heat sink forms a mounting configuration that allows air to circulate around multiple surfaces to maximize heat dissipation. As a result, the LED junction temperature remains low, allowing the LED to by driven with higher currents and generate a higher light output without adverse temperature-related effects.

Claims

1. A light emitting diode, comprising:

an anode;

a thermally conductive cathode, wherein the anode and the cathode are electrically isolated from each other;

a light-emitting diode chip disposed on the cathode and electrically coupled to the anode; and

a heat sink individually associated with the light emitting diode and integrally coupled to at least one of the anode and the cathode.

2. The light emitting diode of claim 1, wherein at least one of the anode and the cathode is made from a thermally and electrically conductive strip that acts as both a thermal and electrical connector.

3. The light emitting diode of claim 2, wherein the electrically conductive strip is bent to extend through an opening in a printed circuit board.

4. The light emitting diode of claim 1, further comprising a heat equalizer coupled to the anode and the cathode.

5. The light emitting diode of claim 4, wherein the heat equalizer is made from a thermally conductive strip.

6. The light emitting diode of claim 5, wherein the anode and the cathode are planar and wherein the thermally conductive strip forming the heat equalizer is bent to extend below a bottom surface of a printed circuit board.

7. The light emitting diode of claim 1, wherein the cathode has a lead portion and an extension portion, wherein the lead portion is constructed for soldering to a printed circuit board and wherein the extension portion acts as a heat sink.

8. The light emitting diode of claim 1, wherein the light emitting diode chip is disposed on the cathode, and wherein the anode is disposed on the cathode and has a hole surrounding the light emitting diode chip.

9. The light emitting diode of claim 8, wherein the anode is an anode ring.

10. The light emitting diode of claim 8, wherein the cathode is planar and acts as a heat sink.

11. A printed circuit board having a top surface and a bottom surface, comprising:

at least one light emitting diode having

an anode,

a thermally conductive cathode, wherein the anode and the cathode are electrically isolated from each other,

a light-emitting diode chip disposed on the cathode and electrically coupled to the anode,

a heat sink individually associated with the light emitting diode and integrally coupled to at least one of the anode and the cathode, and

a lens covering the light-emitting diode chip; and

an electrical connection between said at least one light emitting diode and the printed circuit board.

12. The printed circuit board of claim 11, wherein at least one of the anode and the cathode are made from a conductive strip and acts as both a thermal and electrical connector.

13. The printed circuit board of claim 12, wherein at least one of the anode and the cathode is bent and pushed through an opening in the printed circuit board such that a portion of said at least one of the anode and cathode extends below the bottom surface of the printed circuit board.

14. The printed circuit board of claim 13, further comprising a heat equalizer disposed on the top surface of the printed circuit board, wherein at least one of the anode and the cathode is disposed on the heat equalizer.

15. The printed circuit board of claim 11, further comprising a heat equalizer coupled to the anode and the cathode, wherein the heat equalizer acts as an additional heat sink.

16. The printed circuit board of claim 15, wherein the anode and the cathode are disposed on the top surface of the printed circuit board and wherein the heat equalizer has at least one bent portion that extends below the bottom surface of the printed circuit board.

17. The printed circuit board of claim 15, wherein the cathode has at least one lead and an extension, wherein the lead is used to electrically couple the light emitting diode to the printed circuit board.

18. The printed circuit board of claim 17, wherein the extension is coupled to the top surface of the printed circuit board.

19. The printed circuit board of claim 17, wherein the extension is inserted through at least one opening in the printed circuit board to extend below the bottom surface of the printed circuit board.

20. The printed circuit board of claim 17, wherein a first part of the extension portion is coupled to the bottom surface of the printed circuit board such that the lens extends through an opening in the printed circuit board, and wherein a second part of the extension portion extends below the bottom surface of the printed circuit board.

21. The printed circuit board of claim 11, wherein the anode is disposed on the cathode and has a hole surrounding the light emitting diode chip.

22. The printed circuit board of claim 21, wherein the anode is an anode ring, and wherein the anode ring is coupled to the bottom surface of the printed circuit board such that the lens extends through an opening in the printed circuit board.

23. The printed circuit board of claim 21, wherein the cathode is planar and acts as a heat sink.

24. The printed circuit board of claim 23, wherein the cathode is coupled to a system heat sink.

25. The printed circuit board of claim 23, wherein the cathode is coupled to the bottom surface of the printed circuit board such that the lends extends through an opening in the printed circuit board.

26. The printed circuit board of claim 23, wherein the cathode is bent and inserted through at least one opening in the printed circuit board such that a portion cathode extends below the bottom surface of the printed circuit board.