Mitsui Minings & Melting Co., Ltd.

Osamu Nakano

Makoto Dobashi

Naotomi Takahashi

Takashi Kataoka

Hiroshi Watanabe

Tsutomu Higuchi

Masaru Takahashi

Sakiko Taenaka

Noriko Hanzawa

Yoichi Babasaki

Naohito Uchida

A copper foil for use in making a printed wiring board and a copper clad laminate comprising the copper foil are herein disclosed and the copper foil is characterized in that a metal chromium layer is formed on at least one side of the copper foil by vapor deposition or characterized in that one side of the copper foil is supported by a carrier through a releasing layer and a metal chromium layer is formed on the other side of the foil by vapor deposition. The copper foil is excellent in the adhesion to various substrates (the peel strength between the substrate and the copper foil), moisture resistance, chemical resistance and heat resistance and therefore, the copper foil can suitably be used in the production of printed wiring boards.

Copper foil for printed wiring board

An object of the present invention is to provide a copper foil having excellent adhesion to an etching resist layer, without performing physical polishing such as buffing in pre-treatment of an etching process to form a circuit from the copper foil. To attain the object, in electroforming, a titanium material having a grain size number of 6.0 or more is employed as a copper deposition surface of the rotating drum cathode, and glue and/or gelatin is added in an amount of 0.2-20 mg/l to a copper sulfate solution, thereby producing a drum foil. An electrodeposited copper foil obtained from the drum foil, wherein 20% or more of the crystals present in a shiny side surface of the electrodeposited copper foil have a twin-crystal structure, is used for producing copper-clad laminates.

Electrodeposited copper foil

Growing community of inventors

Saitama, Japan

Osamu Nakano