Surface-treated copper foil for high-frequency circuit and method for producing the same

Abstract

The invention proposes a method for producing a surface treated copper foil (28), comprising the steps of: a) providing an untreated electrolytic copper foil (18) with a first surface (18.1) and a second surface (18.2) opposite to the first surface, preferably having a surface roughness Rz ISO inferior or equal to 0.8 µm on a first surface (18.1); b) performing a roughening treatment on at least one surface (18.1) of the copper foil (18) in an electro etching cell (20) with the copper foil (18) at anodic potential, to achieve a surface roughness Rz ISO of no more than 0.8 µm, a surface roughness Sa of 30 nm or less and a negative skewness Ssk, wherein step b) comprises applying a current density of 1 to 30 A / dm2 and wherein during the roughening treatment the current density is applied with a duration between 1 and 10s. The invention also relates to such a treated copper foil for use in a printed circuit board.