Composite and method for making thin copper foil

Abstract

The improved method of the invention comprises disposing a chromium oxide release layer on the surface of a thin inexpensive metal carrier, such as foil, depositing copper on the release layer to form a thin copper foil, and readily peeling the thus-formed copper foil from the release layer on the carrier. The release layer can be formed in situ from chromium metal electroplated on the carrier. The freshly prepared release layer contains numerous small sites on which electroplating of the copper can be easily carried out to produce pore-free copper foil. The method, which employs the carrier-release layer composite of the invention, is inexpensive and efficient, since readily available, inexpensive metal carriers can be used and no complicated copper foil-carrier separation steps need be resorted to. Moreover, it can increase the bondability of the thin copper foil thus produced to plastic during lamination thereof.

Dependencies are inferred from the claim text.