Graphite sheet, method for producing same, laminated board for wiring, graphite wiring material, and process for producing wiring board

Patent metadata

Field	Value
Publication number	US-9807878-B2
Application number	US-201415025075-A
Country	US
Kind code	B2
Filing date	Aug 7, 2014
Priority date	Sep 26, 2013
Publication date	Oct 31, 2017
Grant date	Oct 31, 2017

Abstract

The first present invention is a graphite sheet having a thickness of not more than 9.6 μm and more than 50 nm and a thermal conductivity along the a-b plane direction at 25° C. of 1950 W/mK or more. The second present invention is a graphite sheet having a thickness in a range of less than 9.6 μm and 20 nm or more, an area of 9 mm2 or more, and a carrier mobility along the a-b plane direction at 25° C. of 8000 cm2/V·sec or more.

First claim

The invention claimed is:

1. A graphite sheet (i) having a thickness of 9.6 μm or less and more than 50 nm and a thermal conductivity along the a-b plane direction at 25° C. of 1950 W/mK or more, or (ii) having a thickness in a range of less than 9.6 μand 20 nm or more, an area of 9 mm 2 or more, and a carrier mobility along the a-b plane direction at 25° C. of 8000 cm 2 /V·sec or more.

2. The graphite sheet according to claim 1 , having the thermal conductivity of 2080 W/mK or more.

3. The graphite sheet according to claim 1 , having an area of 4 mm 2 or more.

4. The graphite sheet according to claim 1 , having a density of 1.8 g/cm 3 or more.

5. The graphite sheet according to claim 1 , having an average crystal grain size of 2 μm or more.

6. The graphite sheet according to claim 1 , having a characteristic of current density resistance of 2×10 6 A/cm 2 or more.

7. The graphite sheet according to claim 1 , having a thickness of 2.1 μm or less.

8. The graphite sheet according to claim 1 , (i) having a thickness of less than 9.6 μm and 20 nm or more, and being obtained by forming an aromatic polymer into a film having a thickness in a range of not more than 25 μm and not less than 30 nm and heat-treating the obtained aromatic polymer film at a temperature of 3000° C. or higher, or (ii) having a thickness of 2.1 μm or less, and being obtained by forming an aromatic polymer into a film having a thickness in a range of not more than 6 μm and not less than 30 nm and heat-treating the obtained aromatic polymer film at a temperature of 3000° C. or higher.

9. The graphite sheet according to claim 8 , wherein a heat treatment at 3000° C. or higher is performed in an inert gas, and a gauge pressure of the inert gas is 0.09 MPa or more.

10. The graphite sheet according to claim 8 , wherein the aromatic polymer is at least one selected from polyimide, polyamide, polyquinoxaline, polyoxadiazole, polybenzoimidazole, polybenzooxazole, polybenzothiazole, polyquinazolinedione, polybenzoxazinone, polyquinazolone, a benzimidazobenzophenanthroline ladder polymer, and derivatives thereof.

11. A laminated board for wiring, wherein the graphite sheet according to claim 1 is laminated on an insulating organic polymer film or an insulating inorganic substrate.

12. The laminated board for wiring according to claim 11 , wherein the graphite sheet is bonded to the insulating organic polymer film or the insulating inorganic substrate with a thermoplastic polymer.

13. A graphite wiring material, being formed by partially removing the graphite sheet according to claim 1 .

14. The graphite wiring material according to claim 13 , having a width of wiring of 2 mm or less.

15. A method for producing a wiring board, wherein the graphite wiring material according to claim 13 is formed by etching of a laser, and the laser is a carbon dioxide laser, a YAG laser, a YVO 4 laser, a fiber laser or an excimer laser.

Assignees

• Kaneka Corp

Inventors

• Tatami Atsushi
• Murakami Mutsuaki
• Tachibana Masamitsu

Classifications

• C01B32/205

  Preparation · CPC title

• B32B27/281

  comprising polyimides · CPC title

• H05K3/4611

  by laminating two or more circuit boards (H05K3/4652 takes precedence) · CPC title

• H05K1/0296

  Conductive pattern lay-out details not covered by sub groups H05K1/02 - H05K1/0295 (H05K1/11 takes precedence; lay-out adapted to mounted component configuration H05K1/18) · CPC title

• B32B2307/302

  Conductive · CPC title