Lightweight heat sinks and LED lamps employing same

Patent metadata

Field	Value
Publication number	US-10240772-B2
Application number	US-97947610-A
Country	US
Kind code	B2
Filing date	Dec 28, 2010
Priority date	Apr 2, 2010
Publication date	Mar 26, 2019
Grant date	Mar 26, 2019

Abstract

A heat sink comprises a heat sink body, which in some embodiments is a plastic heat sink body, and a thermally conductive layer disposed over the heat sink body. In some embodiments the thermally conductive layer comprises a copper layer. A light emitting diode (LED)-based lamp comprises the aforementioned heat sink and an LED module including one or more LED devices in which the LED module is secured with and in thermal communication with the heat sink. Some such LED-based lamps may have an A-line bulb configuration or an MR or PAR configuration. Disclosed method embodiments comprise forming a heat sink body and disposing a thermally conductive layer on the heat sink body. The forming may comprise molding the heat sink body, which may be plastic. In some method embodiments the heat sink body includes fins and the disposing includes disposing the thermally conductive layer over the fins.

First claim

The invention claimed is:

1. A heat sink comprising:
a heat sink body and heat radiating fins, said fins including a first edge engaging said body and a remote second edge, side walls extending between said first edge and said second edge, said body and fins being comprised of a plastic; and
a thermally conductive layer disposed over at least the side walls of said heat sink fins, said thermally conductive layer extending between said first edge and said second edge, wherein the thermally conductive layer has a thickness of 500 micron or less and a thermal conductivity of 50 W/m·K or higher.

2. The heat sink of claim 1 , wherein the thermally conductive layer has a thickness of at least 100 micron.

3. The heat sink of claim 1 , wherein the thermally conductive layer has a thermal sheet conductance of at least 0.025 W/K.

4. The heat sink of claim 1 , wherein the thermally conductive layer has a thermal sheet conductance of at least 0.05 W/K.

5. The heat sink of claim 1 , wherein the heat sink, body and fins do not include any metal or electrically conductive filler material.

6. The heat sink of claim 1 , wherein the fins have a roughened surface and the thermally conductive layer disposed on the roughened surface conforms with the roughened surface.

7. The heat sink of claim 1 , wherein the thermally conductive layer comprises copper.

8. A heat sink comprising:
a heat sink body and heat radiating fins, said fins including a first edge engaging said body and a remote second edge, side walls extending between said first edge and said second edge, said body and fins being comprised of a plastic; and
a thermally conductive layer disposed over at least the side walls of said heat sink fins, said thermally conductive layer extending between said first edge and said second edge, wherein the thermally conductive layer has a thermal sheet conductance of at least 0.0025 W/K.

9. A heat sink comprising:
a heat sink body and heat radiating fins, said fins including a first edge engaging said body and a remote second edge, side walls extending between said first edge and said second edge, said body and fins being comprised of a plastic; and
a thermally conductive layer disposed over at least the side walls of said heat sink fins, said thermally conductive layer extending between said first edge and said second edge, said heat sink further comprising a polymeric layer disposed between the fins and the thermally conductive layer and extending between the first edge and the second edge.

10. The heat sink of claim 9 , wherein the polymeric layer has a thickness of between 2 microns and 10 microns inclusive.

11. The heat sink of claim 9 , further comprising at least one of a powder coating, paint, lacquer, and polymer disposed on the thermally conductive layer.

12. A heat sink comprising:
a heat sink body and heat radiating fins, said fins including a first edge engaging said body and a remote second edge, side walls extending between said first edge and said second edge, said body and fins being comprised of a plastic; and
a thermally conductive layer disposed over at least the side walls of said heat sink fins, said thermally conductive layer extending between said first edge and said second edge, the thermally conductive layer comprising:
a copper layer encompassing the heat sink body and fins; and
a passivating metal layer disposed on the copper layer.

13. The heat sink of claim 12 , wherein the passivating metal layer is selected from a group consisting of a nickel layer, a chromium layer, and a platinum layer.

14. The heat sink of claim 12 , wherein the copper layer has a thickness of at least 150 micron and the passivating metal layer has a thickness of no more than ten microns.

15. A heat sink comprising:
a heat sink body and heat radiating fins, said fins including a first edge engaging said body and a remote second edge, side walls extending between said first edge and said second edge, said body and fins being comprised of a plastic; and
a thermally conductive layer disposed over at least the side walls of said heat sink fins, said thermally conductive layer extending between said first edge and said second edge, wherein the fins are thermally insulating.

16. A heat sink comprising:
a heat sink body and heat radiating fins, said fins including a first edge engaging said body and a remote second edge, side walls extending between said first edge and said second edge, said body and fins being comprised of a plastic; and
a thermally conductive layer disposed over at least the side walls of said heat sink fins, said thermally conductive layer extending between said first edge and said second edge, wherein the heat sink body includes passages that are coated by the thermally conductive layer disposed over the heat sink body to define thermal shunting paths.

17. A light emitting diode (LED)-based lamp comprising a heat sink having a heat sink body and heat radiating fins, said fins including a first edge engaging said body and a remote second edge, side walls extending between said first edge and said second edge, said body and fins being comprised of a plastic;
a thermally conductive layer disposed over at least the side walls of said heat sink fins, said thermally conductive layer extending between said first edge and said second edge and wherein the thermally conductive layer has a thickness of 500 micron or less and a thermal conductivity of 50 W/m·K or higher; and:
an LED module including one or more LED devices, the LED module secured with and in thermal communication with the heat sink such that the fins are in optical communication with said LED module.

18. The LED-based lamp of claim 17 , wherein the thermally conductive layer of the heat sink comprises copper.

19. The LED-based lamp of claim 17 , wherein the plastic heat sink body comprises a polymeric material selected from a group consisting of poly (methyl methacrylate), nylon, polyethylene, epoxy resin, polyisoprene, sbs rubber, polydicyclopentadiene, polytetrafluoroethulene, poly(phenylene sulfide), poly(phenylene oxide), silicone, polyketone, and a thermoplastic.

20. The LED-based lamp of claim 17 , wherein the LED-based lamp has an A-line bulb configuration.

21. The LED-based lamp of claim 17 , wherein the LED-based lamp has an MR or PAR configuration.

22. The LED-based lamp of claim 17 , wherein the heat sink body includes passages that are coated by the thermally conductive layer disposed over the heat sink body to define thermal shunting paths thermally connecting the LED module with a heat radiating surface of the heat sink.

Assignees

• Chowdhury Ashfaqul I
• Allen Gary R
• Knapp Thomas A
• Ge Lighting Solutions Llc

Inventors

• Chowdhury Ashfaqul I
• Allen Gary R
• Knapp Thomas A

Classifications

• Y10T29/4935

  Heat exchanger or boiler making · CPC title

• F21V29/773 Primary

  the planes containing the fins or blades having the direction of the light emitting axis · CPC title

• F21V29/70

  characterised by passive heat-dissipating elements, e.g. heat-sinks · CPC title

• F21V29/677

  the fans being used for discharging · CPC title

• F21V29/63 Primary

  using electrically-powered vibrating means; using ionic wind · CPC title