GRAPHITE SHEET, METHOD FOR PRODUCING SAME, LAMINATED BOARD FOR WIRING, GRAPHITE WIRING MATERIAL, AND PROCESS FOR PRODUCING WIRING BOARD

• US 20160249453A1
• Filed: 08/07/2014
• Published: 08/25/2016
• Est. Priority Date: 09/26/2013
• Status: Active Grant

• Current Assignee: Kaneka Corporation
• Original Assignee: Kaneka Corporation
• Inventors: TATAMI, Atsushi, TACHIBANA, Masamitsu, MURAKAMI, Mutsuaki
• Granted Patent: US 9,807,878 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B32B 2307/202 Conductive
• CPC Class Codes: B32B 2307/206 Insulating
• CPC Class Codes: B32B 2307/302 Conductive
• CPC Class Codes: B32B 2457/00 Electrical equipment
• CPC Class Codes: B32B 27/20 using fillers, pigments, thixotroping agents
• CPC Class Codes: B32B 27/281 comprising polyimides
• CPC Class Codes: B32B 27/34 comprising polyamides
• CPC Class Codes: B32B 9/007 comprising carbon, e.g. graphite, composite carbon
• CPC Class Codes: B32B 9/045 of synthetic resin
• CPC Class Codes: C01B 2204/04 Specific amount of layers or specific thickness
• CPC Class Codes: C01B 2204/24 Thermal properties
• CPC Class Codes: C01B 2204/32 Size or surface area
• CPC Class Codes: C01B 32/20 Graphite
• CPC Class Codes: C01B 32/205 Preparation
• CPC Class Codes: C01B 32/21 After-treatment
• CPC Class Codes: H05K 1/0296 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 Class Codes: H05K 1/0306 Inorganic insulating substrates, e.g. ceramic, glass
• CPC Class Codes: H05K 1/0353 consisting of two or more materials, e.g. two or more polymers, polymer + filler, + reinforcement
• CPC Class Codes: H05K 1/09 Use of materials for the conductive, e.g. metallic pattern
• CPC Class Codes: H05K 3/027 the conductive material being removed by irradiation, e.g. by photons, alpha or beta particles
• CPC Class Codes: H05K 3/4611 : by laminating two or more circuit boards H05K3/4652 takes precedence

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.

Claims

1-30. -30. (canceled)

31. A graphite sheet (i) having a thickness of 9.6 μ

m 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 μ

m 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.

32. The graphite sheet according to claim 31, having the thermal conductivity of 2080 W/mK or more.

33. The graphite sheet according to claim 31, having an area of 4 mm² or more.

34. The graphite sheet according to claim 31, having a density of 1.8 g/cm³ or more.

35. The graphite sheet according to claim 31, having an average crystal grain size of 2 μ

m or more.

36. The graphite sheet according to claim 31, having a characteristic of current density resistance of 2×

10⁶ A/cm² or more.

37. The graphite sheet according to claim 31, having a thickness of 2.1 μ

m or less.

38. The graphite sheet according to claim 31, (i) having a thickness of less than 9.6 μ

m 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 μ

m 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 μ

m or less, and being obtained by forming an aromatic polymer into a film having a thickness in a range of not more than 6 μ

m and not less than 30 nm and heat-treating the obtained aromatic polymer film at a temperature of 3000°

C. or higher.

39. The graphite sheet according to claim 38, 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.

40. The graphite sheet according to claim 38, 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.

41. A method for producing the graphite sheet according to claim 31, wherein a polymer film is used as a raw material.

42. The method for producing a graphite sheet according to claim 41, wherein the graphite sheet is obtained by heat-treating the polymer film at a temperature of 3000°

C. or higher.

43. The method for producing a graphite sheet according to claim 41, wherein the graphite sheet is obtained by heat-treating the polymer film at a temperature of 3000°

C. or higher for a retention time of 20 minutes or more in an atmosphere pressurized to a gauge pressure of 0.10 MPa or more with an inert gas.

44. The method for producing a graphite sheet according to claim 42, wherein the polymer film has a thickness of 6 μ

m or less.

45. A method for producing the graphite sheet according to claim 31, wherein an aromatic polymer is formed into a film having a thickness in a range of not more than 25 μ

m and not less than 30 nm or a thickness in a range of not more than 6 μ

m and not less than 30 nm, the resulting aromatic polymer film is heat-treated at a temperature of 3000°

C. or higher, and a thickness of the heat-treated film is less than 9.6 μ

m and 20 nm or more.

46. The method for producing a graphite sheet according to claim 45, 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.

47. The method for producing a graphite sheet according to claim 41, wherein the polymer film is an aromatic polymer film characterized by being at least one selected from polyamide, polyimide, polyquinoxaline, polyoxadiazole, polybenzoimidazole, polybenzooxazole, polybenzothiazole, polyquinazolinedione, polybenzoxazinone, polyquinazolone, a benzimidazobenzophenanthroline ladder polymer, and derivatives thereof.

48. The method for producing a graphite sheet according to claim 41, wherein the polymer film is a film of an aromatic polyimide.

49. The method for producing a graphite sheet according to claim 48, wherein the polymer film is an aromatic polyimide film obtained by using at least one selected from pyromellitic anhydride and 3,3′

,4,4′

-biphenyltetracarboxylic dianhydride as a raw material.

50. The method for producing a graphite sheet according to claim 48, wherein the polymer film is an aromatic polyimide film obtained by using at least one selected from 4,4′

-diaminodiphenyl ether and p-phenylenediamine as a raw material.

51. The method for producing a graphite sheet according to claim 45, wherein an amount of a filler added in forming a film of the aromatic polymer is 0.1% by mass or less of the entire aromatic polymer film.

52. A laminated board for wiring, wherein the graphite sheet according to claim 31 is laminated on an insulating organic polymer film or an insulating inorganic substrate.

53. The laminated board for wiring according to claim 52, wherein the graphite sheet is bonded to the insulating organic polymer film or the insulating inorganic substrate with a thermoplastic polymer.

54. A graphite wiring material, being formed by partially removing the graphite sheet according to claim 31.

55. The graphite wiring material according to claim 54, having a width of wiring of 2 mm or less.

56. A method for producing a wiring board, wherein the graphite wiring material according to claim 54 is formed by etching of a laser, and the laser is a carbon dioxide laser, a YAG laser, a YVO₄ laser, a fiber laser or an excimer laser.