Thermal interface material

• US 6,746,768 B2
• Filed: 12/26/2001
• Issued: 06/08/2004
• Est. Priority Date: 12/26/2001
• Status: Expired due to Term

• Current Assignee: NeoGraf Solutions, LLC
• Original Assignee: Advanced Energy Technology Inc. (Graftech International Limited)
• Inventors: Krassowski, Daniel W., Greinke, Ronald A.
• Primary Examiner(s): Jones, Deborah
• Assistant Examiner(s): BOSS, WENDY L
• Application Number:
  US10/027,207
• Publication Number:
  US 20030118826A1
• Time in Patent Office: 895 Days
• Field of Search: 428/408, 428/447, 428/497, 428/499, 361/708, 361/709, 423/414, 423/445.R, 423/448, 165/185, 165/905, 165/907
• US Class Current: 428/408
• CPC Class Codes: B32B 2315/02 Ceramics
• CPC Class Codes: C04B 2235/522 Oxidic
• CPC Class Codes: C04B 2235/524 Non-oxidic, e.g. borides, carbides, silicides or nitrides
• CPC Class Codes: C04B 2235/526 characterised by the length of the fibers
• CPC Class Codes: C04B 2235/608 Green bodies or pre-forms with well-defined density
• CPC Class Codes: C04B 2237/363 Carbon
• CPC Class Codes: C04B 35/536 based on expanded graphite or complexed graphite
• CPC Class Codes: C04B 37/008 by means of an interlayer consisting of an organic adhesive, e.g. phenol resin or pitch
• CPC Class Codes: F28F 13/00 Arrangements for modifying heat-transfer, e.g. increasing, decreasing F28F1/00 - F28F11/00 take precedence
• CPC Class Codes: F28F 21/02 of carbon, e.g. graphite
• CPC Class Codes: H01L 23/373 Cooling facilitated by selection of materials for the device or materials for thermal expansion adaptation, e.g. carbon
• 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: Y10S 165/905 Materials of manufacture
• CPC Class Codes: Y10S 165/907 Porous
• CPC Class Codes: Y10T 428/26 Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension
• CPC Class Codes: Y10T 428/30 Self-sustaining carbon mass or layer with impregnant or other layer
• CPC Class Codes: Y10T 428/31663 As siloxane, silicone or silane
• CPC Class Codes: Y10T 428/31844 Of natural gum, rosin, natural oil or lac

Abstract

A thermal interface and a thermal interface as part of a thermal management system that comprises a heat source, and a cooling module. The heat source has an external surface; the thermal interface is a flexible graphite sheet article having two parallel planar surfaces, with the first planar surface of the thermal interface being in operative contact with the external surface of the heat source and the second planar surface being in contact with the cooling module. The graphite sheet contains oil.

Claims

1. A thermal management system, comprising:

(1) a heat source having an external surface;

(2) a thermal interface which comprises an anisotropic flexible graphite sheet article that contains oil, the thermal interface being in operative communication with the external surface of the heat source; and

(3) a heat dissipating component having a heat collection surface and a heat dissipation surface, the heat collection surface being in operative communication with the thermal interface;

wherein arranging the heat collection surface in operative connection with the thermal interface causes dissipation of heat form the heat source.

2. The thermal management system of claim 1, wherein the oil is mineral oil, vegetable oil, synthetic oil, edible oil, edible oil, animal oil, and mixtures thereof.

3. The thermal interface material of claim 1, wherein the oil is mineral oil.

4. The thermal management system of claim 1, wherein the heat source is an electronic component.

5. The thermal management system of claim 1, wherein the planar area of the thermal interface is greater than the area of the external surface of the heat source.

6. The thermal management system of claim 1 wherein the flexible graphite sheet article is formed by compressing exfoliated particles of natural graphite.

7. The thermal management system of claim 1 wherein the thermal interface material has a thickness of from about 0.05 mm to about 1.0 mm.

8. The thermal management system of claim 1, wherein the oil comprises ester type oil.

9. The thermal management system of claim 1, wherein the nil comprises a polyalfaolefin oligomer.

10. The thermal management system of claim 1, wherein the oil comprises an alkylated benzene.

11. The thermal management system of claim 1 wherein the thermal interface comprises a laminate of flexible graphite sheets.

12. A thermal management system comprising;

(a) a beat source which comprises an electronic component, the heat source having an external surface;

(b) a thermal interface comprising an anisotropic flexible graphite sheet article having two parallel planar surfaces extending in a direction parallel to the planar direction of the crystal structure of the graphite in the sheet, the first of the planar surfaces of the thermal interface being in operative contact with the external surface of the heat source;

wherein the graphite sheet comprises at least 2% by weight of mineral oil, and wherein the planar area of the first planar surface for the thermal interface is greater than the area of the external surface of the heat source; and

(c) a heat sink comprising a heat collection surface and at least one heat dissipation surface, the heat collection surface of the heat sink being in operative contact with the second of the planar surfaces of the thermal interface.

13. The thermal management system of claim 12 wherein graphite sheet comprises about 2% to about 75% by weight of mineral oil.

14. The thermal management system of claim 12 wherein graphite sheet comprises about 10% to about 55% by weight of mineral oil.

15. The thermal management system of claim 12, wherein the mineral oil has a viscosity of from about 10 to 50 cps.

16. The thermal management system of claim 12 wherein the thermal interface comprises a laminate of flexible graphite sheets.

17. A method of dissipating heat from a heat source, comprising:

(a) providing an heat sink, and providing a thermal interface, the thermal interface comprising an anisotropic flexible graphite sheet article having first and second parallel planar surfaces and having about 2% to about 75% by weight of mineral oil incorporated into the graphite sheet;

(b) placing the first parallel surface of the thermal interface in heat conducting engagement with a heat source, and placing the second parallel surface of the thermal interface in heat conducting engagement with the heat sink; and

(c) conducting heat from the heat source through the thermal interface and into the beat sink.

18. The thermal management system of claim 17 wherein the thermal interface comprises a laminate of flexible graphite sheets.

19. A thermal management system, comprising:

(1) a heat source having an external surface; and

(2) a thermal interface which comprise an anisotropic flexible graphite sheet that contains oil, the thermal interface being in operative communication with the external surface of the heat source.

20. The thermal management system of claim 19, wherein the oil is mineral oil, vegetable oil, synthetic oil, essential oil, edible oil, animal oil, and mixtures thereof.

21. The thermal interface material of claim 19, wherein the oil is mineral oil.

22. The thermal management system of claim 19, wherein the heat source is an electronic component.

23. The thermal management system of claim 19, wherein the planar area of the thermal interface is greater than the area of the external surface of the heat source.

24. The thermal management system of claim 19 wherein the flexible graphite sheet is farmed by compressing exfoliated particles of natural graphite.

25. The thermal management system of claim 19 wherein the thermal interface material has a thickness of from about 0.05 mm to about 1.0 mm.

26. The thermal management system of claim 19 wherein the thermal interface comprises a laminate of flexible graphite sheets.