METAL FOIL AND ELECTRONIC DEVICE

摘要

Provided is a metal foil that is suitable as an electrode substrate for forming elements, said metal foil being capable of inhibiting the oxidation of an ultra-flat surface while preventing winding damage when placed in a rolled state. This metal foil comprises copper or a copper alloy. The surface of the metal foil is an ultra-flat surface having an arithmetic average roughness (Ra) of not more than 30 nm, as measured in accordance with JIS B 0601-2001. The underside of the metal foil is a predominately recessed surface in which the maximum valley depth of a profile curve (Pv) with respect to the maximum peak height of the profile curve (Pp) (i.e., the ratio Pv/Pp), as measured in a rectangular area of 181 mum × 136 mum in accordance with JIS B 0601-2001, is at least 1.5.