Fluororesin film, copper-clad laminate and substrate for circuit

Patent metadata

Field	Value
Publication number	US-2023363090-A1
Application number	US-202318353471-A
Country	US
Kind code	A1
Filing date	Jul 17, 2023
Priority date	Jan 20, 2021
Publication date	Nov 9, 2023
Grant date	—

Abstract

A fluororesin film including a fluorine-containing composition, wherein the oxygen element percentage as measured when heat treatment is performed at 180° C. for 3 minutes and then the state of one or both surfaces of the film is observed by scanning X-ray photoelectron spectroscopy (XPS/ESCA) is 1.35 atom % or more, and an absolute value of the rate of dimensional change in MD and TD before and after heat treatment as measured when the film is heat-treated at 180° C. for 10 minutes and then cooled to room temperature is 2% or less. Also disclosed is a copper-clad laminate, including copper foil and the fluororesin film; a substrate for circuit, including the copper-clad laminate; and a method for producing the copper-clad laminate.

First claim

What is claimed is:

1 . A fluororesin film that is a film comprising a fluororesin-containing composition,
wherein an oxygen element percentage as measured when heat treatment is performed at 180° C. for 3 minutes and then the state of one or both surfaces of the film is observed by scanning X-ray photoelectron spectroscopy (XPS/ESCA) is 1.35 atom % or more, and an absolute value of a rate of dimensional change in MD and TD before and after heat treatment as measured when the film is heat-treated at 180° C. for 10 minutes and then cooled to 25° C. is 2% or less.

2 . The fluororesin film according to claim 1 , wherein the oxygen element percentage is 1.5 atom % or more.

3 . The fluororesin film according to claim 1 , wherein the fluororesin film comprises tetrafluoroethylene-perfluoroalkyl vinyl ether (PFA) or tetrafluoroethylene-hexafluoropropylene (FEP).

4 . The fluororesin film according to claim 1 , wherein a difference between an oxygen element percentage measured when the state of one or both surfaces of the film is observed by scanning X-ray photoelectron spectroscopy (XPS/ESCA) and an oxygen element percentage measured by scanning X-ray photoelectron spectroscopy (XPS/ESCA) after etching the film by argon gas cluster ion beams at an incident angle of 45° in the direction of the depth for 15 minutes is 1.0 atom % or more.

5 . The fluororesin film according to claim 1 , wherein one or both surfaces of the fluororesin film have an adhesion strength of more than 30 N/m when the surfaces of the film are mutually bonded at 200° C.

6 . The fluororesin film according to claim 1 , wherein the fluororesin film has a dielectric loss tangent at 10 GHz of less than 0.0015.

7 . The fluororesin film according to claim 1 , wherein the fluororesin film has a dielectric loss tangent at 40 GHz of less than 0.0015.

8 . The fluororesin film according to claim 1 , wherein the number of unstable terminal groups is less than 10 per 10 6 carbon atoms in a main chain of the fluororesin.

9 . The fluororesin film according to claim 1 , wherein the fluororesin film has an adhesion strength of 0.8 N/mm or more when bonded to copper foil having a surface roughness Rz of 1.5 μm or less.

10 . The fluororesin film according to claim 1 , wherein the fluororesin film is used for a copper-clad laminated board.

11 . A copper-clad laminate, comprising copper foil and the fluororesin film according to claim 1 as essential layers.

12 . The copper-clad laminate according to claim 11 , further comprising a layer other than the copper foil or the fluororesin film,
wherein the layer other than the copper foil or the fluororesin film is at least one selected from the group consisting of polyimide, liquid crystal polymer, polyphenylene sulfide, a cycloolefin polymer, polystyrene, epoxy resin, bismaleimide, polyphenylene oxide, polyphenylene ether and polybutadiene.

13 . The copper-clad laminate according to claim 11 , wherein the copper foil has a surface roughness Rz of 1.5 μm or less.

14 . The copper-clad laminate according to claim 11 , wherein the copper-clad laminate has an adhesion strength between the copper foil and the fluororesin film of 0.8 N/mm or more.

15 . A substrate for circuit, comprising the copper-clad laminate according to claim 11 .

16 . A method for producing the copper-clad laminate according to claim 11 , comprising preheating a fluororesin film at the glass transition temperature or more and less than the melting point of the film, and then bonding the film to copper foil and/or a substrate other than the copper foil or the fluororesin.

Assignees

• Daikin Ind Ltd

Inventors

• Komori Hirokazu
• Higuchi Tatsuya
• Takahashi Kenzo
• Kawamura Masahiko
• Yokotani Koji
• Terada Junpei
• Komatsu Nobuyuki

Classifications

• H05K1/0326 Primary

  containing O · CPC title

• C08J5/18 Primary

  Manufacture of films or sheets · CPC title

• C08J5/121

  by heating · CPC title

• C08J2327/18

  Homopolymers or copolymers of tetrafluoroethylene · CPC title

• C08J2327/24

  halogenated · CPC title