Abstract: A high tensile strength copper foil having a matte side roughness Rz of 2.5 &mgr;m or less and a tensile strength of 40,000 Kgf/mm2 after heating one hour at 180° C. is produced by a process in which copper is electrodeposited from a solution containing predetermined small amounts of a polyether glycol and tin and iron ions. The chloride ion content is maintained below 0.1 wt. ppm. The copper foil is characterized by having copper crystals with atomic cells having a predominently (111) orientation.

Abstract: This invention provides a composite foil comprising an aluminum carrier layer and an ultra-thin copper foil having a protective layer disposed between them comprising a porous copper layer and an interpenetrating zinc layer. A process for producing such composite foils comprises the steps of preparing the surface of the aluminum carrier, electrodepositing a porous copper layer on the aluminum carrier layer followed by electrodepositing a zinc layer, and then electrodepositing two layers of copper to form the ultra-thin copper foil. The composite foil provides a uniform bond strength between the aluminum carrier and the protective layer which is adequate to prevent separation of the carrier and ultra-thin copper foil during handling and lamination, but which is significantly lower than the peel strength of a copper/substrate bond, so that the carrier can easily be removed after lamination of the composite foil to an insulating substrate.

Abstract: An organic rust-roof treated copper foil characterized in that it has a metallic rust-proof layer formed on the non-adhesive side of the original copper foil and has an organic rust-proof layer formed on said metallic rust-proof layer, the organic rust-proof layer comprising a mixture of at least two kinds of chemicals selected from the group consisting of benzotriazole, its derivatives, aminotriazole and its isomers and derivatives is provided with on said metallic rust-proof layer, or it further has a chromate-treated layer formed between said metallic rust-proof layer and said organic rust-proof layer.

Abstract: A high tensile strength copper foil having a matte side roughness Rz of 2.5 .mu.m or less and a tensile strength of 40,000 Kgf/mm.sup.2 after heating one hour at 180.degree. C. is produced by a process in which copper is electrodeposited from a solution containing predetermined small amounts of a polyether glycol and tin and iron ions. The chloride ion content is maintained below 0.1 wt. ppm. The copper foil is characterized by having copper crystals with atomic cells having a predominantly (111) orientation.