Thermal transfer coating

• US 20070102070A1
• Filed: 11/07/2005
• Published: 05/10/2007
• Est. Priority Date: 11/07/2005
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Palmgren, Gary, Tuma, Phillip
• Granted Patent: US 7,695,808 B2
• Time in Patent Office: Days
• US Class Current: 148/512
• CPC Class Codes: C23C 26/00 Coating not provided for in groups C23C2/00 - C23C24/00
• CPC Class Codes: C23C 28/023 only coatings of metal elements only
• CPC Class Codes: C23C 28/321 with at least one metal alloy layer
• CPC Class Codes: C23C 28/322 only coatings of metal elements only
• CPC Class Codes: C23C 28/341 with at least one carbide layer
• CPC Class Codes: F28F 13/187 especially adapted for evaporator surfaces or condenser surfaces, e.g. with nucleation sites
• CPC Class Codes: H01L 23/3732 Diamonds
• CPC Class Codes: H01L 23/3733 having a heterogeneous or anisotropic structure, e.g. powder or fibres in a matrix, wire mesh, porous structures H01L23/3732, H01L23/3737 take precedence
• CPC Class Codes: H01L 23/3736 Metallic materials H01L23/3732, H01L23/3733, H01L23/3735, H01L23/3737, H01L23/3738 take precedence
• CPC Class Codes: H01L 23/427 Cooling by change of state, e.g. use of heat pipes by liquefied gas H01L23/445
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: Y10T 428/25 Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
• CPC Class Codes: Y10T 428/256 Heavy metal or aluminum or compound thereof
• CPC Class Codes: Y10T 428/2991 Coated

Abstract

Thermal transfer coating comprising a plurality of metal bodies and a plurality of interstitial elements disposed between and connecting the plurality of metal bodies to one another. The metal bodies comprise an inner portion comprising a first metal and an outer portion comprising an alloy comprising the first metal and a second metal. The interstitial elements comprise the alloy of the outer portion.

Claims

1. A thermal transfer coating comprising:

a plurality of metal bodies comprising an inner portion comprising a first metal selected from the group consisting of aluminum, copper, silver, and alloys thereof, and an outer portion comprising an alloy comprising the first metal and a second metal selected from the group consisting of copper, silver, and magnesium, wherein said first metal and said second metal are different; and

a plurality of interstitial elements disposed between and connecting said plurality of metal bodies to one another, said interstitial elements comprising said alloy of said outer portion;

wherein said thermal transfer coating has an effective porosity of at least 10 percent.

2. The thermal transfer coating of claim 1 wherein said first metal comprises copper and said second metal comprises silver.

3. The thermal transfer coating of claim 1 wherein said first metal is copper and said interstitial element comprises an alloy of silver and copper.

4. The thermal transfer coating of claim 1 wherein said first metal comprises aluminum and said second metal comprises magnesium.

5. The thermal transfer coating of claim 1 wherein said first metal is aluminum and said interstitial element comprises an alloy of aluminum and magnesium.

6. The thermal transfer coating of claim 1 wherein said inner portion further comprises diamond.

7. The thermal transfer coating of claim 6 wherein said diamond comprises an intermediate coating comprising a carbide former selected from the group consisting of chromium, cobalt, manganese, molybdenum, nickel, silicon, tantalum, titanium, tungsten, vanadium, zirconium, and alloys thereof.

8. The thermal transfer coating of claim 1 wherein said plurality of metal bodies have a unit density in the range of 10⁷ to 10⁹ metal bodies per cubic centimeter.

9. The thermal transfer coating of claim 1 wherein said metal bodies are substantially spherical.

10. The thermal transfer coating of claim 9 wherein said metal bodies comprise an average diameter in the range of 5 to 50 micrometers.

11. The thermal transfer coating of claim 1 wherein said metal bodies comprises an aspect ratio in the range of 1 to 2.

12. The thermal transfer coating of claim 1 wherein said coating comprises a thickness in the range of 20 to 500 micrometers.

13. The thermal transfer coating of claim 1 wherein said thermal transfer coating has an effective porosity of at least 20 percent.

26. A cooling system comprising the thermal transfer coating of claim 1.

35. A method of cooling a heat-dissipating device comprising:

providing a heat dissipating substrate having an outer surface;

applying the thermal transfer coating of claim 1 onto said outer surface; and

contacting said thermal transfer coating with a cooling fluid.

36. The method of claim 35 wherein said method comprises single phase heat transfer.

37. The method of claim 35 wherein said method comprise two phase heat transfer.

38. The method of claim 37 wherein said cooling fluid is contained within a thermosyphon.

39. The method of claim 35 further comprising affixing said heat-dissipating substrate to a heat-generating device.

14. A thermal transfer coating comprising:

a plurality of composite bodies comprises an inner portion comprising diamond and a first metal selected from the group consisting of aluminum, copper, silver, and alloys thereof, and an outer portion comprising an alloy comprising the first metal and a second metal selected from the group consisting of copper, silver, and magnesium, wherein said first metal and said second metal are different; and

a plurality of interstitial elements disposed between and connecting said plurality of metal bodies to one another, said interstitial elements comprising said alloy of said outer portion.

15. The thermal transfer coating of claim 14 wherein said first metal comprises copper and said second metal comprises silver.

16. The thermal transfer coating of claim 14 wherein said first metal is copper and said interstitial element comprises an alloy of silver and copper.

17. The thermal transfer coating of claim 14 wherein said first metal comprises aluminum and said second metal comprises magnesium.

18. The thermal transfer coating of claim 14 wherein said first metal is aluminum and said interstitial element comprises an alloy of aluminum and magnesium.

19. The thermal transfer coating of claim 14 wherein said plurality of metal bodies have a unit density in the range of 10⁷ to 10⁹ metal bodies per cubic centimeter.

20. The thermal transfer coating of claim 14 further comprising an intermediate coating affixed to said diamond comprising a carbide former selected from the group consisting of chromium, cobalt, manganese, molybdenum, nickel, silicon, tantalum, titanium, tungsten, vanadium, zirconium, and alloys thereof, wherein said first metal is affixed to said intermediate coating.

21. The thermal transfer coating of claim 14 wherein said metal bodies are cubo-octohedral.

22. The thermal transfer coating of claim 14 wherein said metal bodies comprises an aspect ratio in the range of 1 to 2.

23. The thermal transfer coating of claim 14 wherein said metal bodies comprise an average diameter in the range of 5 to 50 micrometers.

24. The thermal transfer coating of claim 14 wherein said coating comprises a thickness in the range of 20 to 500 micrometers.

25. The thermal transfer coating of claim 14 wherein said thermal transfer coating has an effective porosity of at least 10 percent.

27. A cooling system comprising the thermal transfer coating of claim 14.

28. A method of coating a heat-dissipating substrate comprising:

providing a heat-dissipating substrate having an outer surface;

depositing a composition comprising a binder and a plurality of metal bodies onto said heat-dissipating substrate, said metal bodies comprising an inner portion comprising a first metal having a melting temperature T_mp1, and an outer portion comprising a second metal having a melting temperature T_mp2; and

heating said composition to a temperature less than T_mp1 and T_mp2 to form an alloy comprising said first metal and said second metal that bonds said plurality of metal bodies to one another and said heat-dissipating substrate, wherein said plurality of metal bodies and said alloy form a porous matrix having an effective porosity of at least 10 percent.

29. The method of claim 28 wherein said first metal is selected from the group consisting of aluminum, copper, silver, and alloys thereof.

30. The method of claim 28 wherein said second metal is the group consisting of copper, silver, magnesium, and alloys thereof.

31. The method of claim 28 wherein said first metal comprises copper and said second metal comprises silver.

32. The method of claim 28 wherein said binder is selected from the group consisting of mineral oil, silicone oil, kerosene, and polyvinyl butyral.

33. The method claim 28 wherein said metal bodies further comprise diamond.

34. The method of claim 28 wherein said outer surface of said heat-dissipating substrate comprises a three-dimensional surface.