Abstract: A copper foil for printed circuits of which a shiny side has resin dust resistance, excels in heat discoloration resistance and rust preventiveness, and does not adversely affect the solderability and resist adhesion, and a method of treating the surface of such copper foil. The copper foil for a printed circuit comprises a first layer of zinc alloy composed of zinc and nickel and/or cobalt, formed on the shiny side surface of a copper foil, and a second layer composed of a mixture or compound of benzotriazole derivative and phosphorus compound (and silicon compound) formed on the layer. The method for treating the surface of a copper foil for a printed circuit comprises the steps of forming a first layer of zinc alloy composed of zinc and nickel and/or cobalt by electroplating on the shiny side surface of a copper foil, and forming a second layer by immersing it in an aqueous solution of benzotriazole derivative and phosphorus compound (and silicon compound).

Abstract: A copper foil for printed circuits of which a shiny side has resin dust resistance, excels in heat discloration resistance and rust preventiveness, and does not adversely affect the solderability and resist adhesion, and a method of treating the surface of such copper foil. The copper foil for a printed circuit comprises a first layer of zinc alloy composed of zinc and nickel and/or cobalt, formed on the shiny side surface of a copper foil, and a second layer composed of a mixture or compound of benzotriazole derivative and phosphorus compound (and silicon compound) formed on the layer. The method for treating the surface of a copper foil for a printed, circuit comprises the steps of forming a first layer of zinc alloy composed of zinc and nickel and/or cobalt be electroplating on the shiny side surface of a copper foil, and forming a second layer by immersing it in an aqueous solution of benzotriazole derivative and phosphorus compound (and silicon compound).