Patent ID: 7344785

Claim:
A copper foil for a printed circuit board comprising: a copper foil comprising copper or copper alloy and having a surface to be faced to a base material for a printed circuit board; a zinc galvanized layer provided on a bonding surface of the copper foil; and a trivalent chromate treatment layer directly formed on the zinc galvanized layer; wherein the trivalent chromate treatment layer is formed by using a trivalent chromium conversion treatment solution containing 70 mg/L or more and less than 500 mg/L of trivalent chromium ions converted into metal chromium and having a pH-value of 3.0 to 4.5; and wherein an alloy plating layer composed of Ni and Co is provided between the zinc galvanized layer and the copper foil, and wherein a total coating amount of the Ni and Co is 5 to 20 μg/cm 2 , and a concentration of the cobalt in the alloy layer is 60 to 80 mass %.