Patent attributes
An object of the present invention is to provide a treated copper foil laminated with a mesomorphic polymer film having low hygroscopicity and superior high thermal resistance to make a circuit board composite materials having large peel strength and compatibility with fine pattern processes, which a copper foil being deposited with roughening particles to make the treated copper foil having a roughening treated side with surface roughness of 1.5 to 4.0 μm and luminosity of not more than 30, having projections formed from the roughening particles with a height of 1 to 5 μm, preferably 6 to 35 thereof are uniformly distributed in a 25 μm of surface length of copper foil cross-section observed, and its maximum width being at least 0.01 μm and not more than twice of 25 μm divided by the number of projections in the 25 μm surface length.
