The copper foil of the folding endurance and copper foil backing material which possesses

摘要

PROBLEM TO BE SOLVED: To provide copper foil having improved folding resistance and used for a flexible printed circuit board, and to provide its production method.;SOLUTION: The folding resistant copper foil comprises a copper foil base material having a matte side and a shinny side and a thermally stable layer at least on the matte side of the copper foil base material. The surface of the shinny side in the copper foil base material is preferably provided with a thermally stable layer as well. The thermally stable layer is preferably composed of a copper plating layer in which the decrease in tensile strength caused by heat treatment is lower than that in the copper foil base material.;COPYRIGHT: (C)2005,JPO&NCIPI