Thermal interface material, method for thermally coupling with thermal interface material, and method for preparing thermal interface material

Patent metadata

Field	Value
Publication number	US-11670566-B2
Application number	US-201816483391-A
Country	US
Kind code	B2
Filing date	Jan 30, 2018
Priority date	Feb 2, 2017
Publication date	Jun 6, 2023
Grant date	Jun 6, 2023

Abstract

A thermal interlace material for transferring heat by interposing between two materials may include a graphite film. The graphite film may have a thickness T of 200 nm to 3 μm, and a ratio Ra/T of an arithmetic average roughness Ra on a surface of the graphite film to the thickness T of the graphite film, may be 0.1 to 30.

First claim

The invention claimed is:

1. A thermal interface material for transferring heat by interposing between two materials, wherein:
the thermal interface material comprises a graphite film, the graphite film has a thickness T of 200 nm to 3 μm and a density of 1.70 g/cm 3 or more,
each of the arithmetic average roughness Ra is 0.3 μm to 6.0 μm on a surface of the graphite film,
a ratio Ra/T of an arithmetic average roughness Ra on a surface of the graphite film to the thickness T of the graphite film is 0.1 to 30, and
a thermal resistance of the thermal interface material is 0.3° C.·cm 2 /W or less on a load of 0.1 MPa.

2. The thermal interface material according to claim 1 , wherein a ratio Ra/Rave of each of the arithmetic average roughnesses Ra on two or more parts of the graphite film to an average Rave of the arithmetic average roughnesses Ra is 0.2 to 5.0.

3. The thermal interface material according to claim 1 , wherein the graphite film has a density of 1.70 g/cm 3 or more and 2.26 g/cm 3 or less, and a thermal conductivity of 1000 W/mK to 2000 W/mK in a film plane direction.

4. The thermal interface material according to claim 1 , wherein a ratio R 0.1P /R 0.45P of a thermal resistance R 0.1P on a load of 0.1 MPa to a thermal resistance R 0.45P on a load of 0.45 MPa of the thermal interface material is 1.0 to 1.8.

5. A method for thermally coupling materials with the thermal interface material according to claim 1 , wherein a thermal resistance of the thermal interface material is 0.3° C.·cm 2 /W or less on a load of 0.1 MPa.

6. A method for thermally coupling materials with the thermal interface material according to claim 1 , wherein a ratio R 0.1P /R 0.45P of a thermal resistance R 0.1P on a load of 0.1 MPa to a thermal resistance R 0.45P on a load of 0.45 MPa of the thermal interface material is 1.0 to 1.8.

7. A method for preparing the thermal interface material according to claim 1 , comprising carbonizing a polymer film to form a carbonized film, and graphitizing the carbonized film to form a graphite film.

8. The method according to claim 7 , wherein in at least of the carbonizing step and the graphitizing step, the polymer film, the carbonized film, or the graphite film is supported at multiple points, and the polymer film, the carbonized film, or the graphite film is carbonized and/or graphitized while pressing.

9. The method according to claim 8 , wherein in at least one of the carbonizing step and the graphitizing step, a spacer is laminated on each plane of the polymer film, the carbonized film, or the graphite film, and a laminate of the spacer and the polymer film, the carbonized film, or the graphite film is carbonized and/or graphitized while pressing.

10. The method according to claim 9 , wherein the spacer has a surface roughness Ra of 0.2 μm to 20 μm.

11. The method according to claim 10 , wherein the spacer comprises a felt composed of a carbon fiber or a graphite fiber.

12. The method according to claim 9 , wherein the spacer comprises a felt composed of a carbon fiber or a graphite fiber.

13. The method according to claim 7 , wherein the polymer film comprises a condensed aromatic polymer.

14. The method according to claim 7 , comprising carbonizing and graphitizing the polymer film at a temperature of 2400° C. or more, wherein the polymer film comprises an aromatic polyimide and has a thickness of 300 nm to 7.5 μm.

15. A method for thermally coupling materials with the thermal interface material according to claim 2 , wherein a thermal resistance of the thermal interface material is 0.3° C.·cm 2 /W or less on a load of 0.1 MPa.

16. A method for thermally coupling materials with the thermal interface material according to claim 2 , wherein a ratio R 0.1P /R 0.45P of a thermal resistance R 0.1P on a load of 0.1 MPa to a thermal resistance R 0.45P on a load of 0.45 MPa of the thermal interface material is 1.0 to 1.8.

17. A thermal interface material for transferring heat by interposing between two materials, wherein:
the thermal interface material comprises a graphite film, the graphite film has a thickness T of 200 nm to 3 μm and a density of 1.70 g/cm 3 or more,
each of the arithmetic average roughness Ra is 0.3 μm to 6.0 μm on a surface of the graphite film,
a ratio Ra/T of an arithmetic average roughness Ra on a surface of the graphite film to the thickness T of the graphite film is 0.1 to 30, and
a ratio R 0.1P /R 0.45P of a thermal resistance R 0.1P on a load of 0.1 MPa to a thermal resistance R 0.45P on a load of 0.45 MPa of the thermal interface material is 1.0 to 1.8.

18. The thermal interface material according to claim 17 , wherein a ratio Ra/Rave of each of the arithmetic average roughnesses Ra on two or more parts of the graphite film to an average Rave of the arithmetic average roughnesses Ra is 0.2 to 5.0.

19. The thermal interface material according to claim 17 , wherein the graphite film has a density of 1.70 g/cm 3 or more and 2.26 g/cm 3 or less, and a thermal conductivity of 1000 W/mK to 2000 W/mK in a film plane direction.

20. The thermal interface material according to claim 17 , wherein a thermal resistance of the thermal interface material is 0.3° C.·cm 2 /W or less on a load of 0.1 MPa.

Assignees

• Kaneka Corp

Inventors

• Murakami Mutsuaki
• Tatami Atsushi
• Tachibana Masamitsu

Classifications

• H10W40/25

  characterised by their materials · CPC title

• H10W40/255 Primary

  having a laminate or multilayered structure, e.g. direct bond copper [DBC] ceramic substrates · CPC title

• H10W40/251 Primary

  Organics · CPC title

• C01B32/205

  Preparation · CPC title

• C01P2006/10

  Solid density · CPC title