Abstract: Disclosed is a both-side roughened copper foil with a protection film, comprising a metal foil as soft as or softer than copper, or an organic type film having a melting point equal to or higher than a lamination temperature, laminated on one side of a copper foil with both sides roughened, the metal foil or organic film being continuously or continually bonded or adhered to the copper foil. It is possible to protect the ruggedness on the roughened surface at the time the both-side roughened copper foil is cut, packed, transported or stacked on another both-side roughened copper foil, simplify the press molding work, and improve the production efficiency particularly in the step of fabricating a copper-clad laminated board for a printed circuit board as well as the quality of the acquired copper-clad laminated board.

Abstract: A copper foil for an inner layer circuit of a multi-layered printed circuit board, which comprises a black metal plated layer formed on at least the rough surface which becomes a surface of an inner layer circuit of a copper foil having both sides roughened in advance, in order to enhance the bonding strength to a prepreg, make it safe from haloing and facilitate optical checking of the copper foil.

Abstract: A method for preparing a copper-clad laminated board for a printed circuit board which comprises: (a) preparing a prepreg by permeating a thermosetting resin into a fabric and then drying the resulting material to a half-hardened state, (b) laminating a both-side roughened copper foil on both sides or one side of the prepreg or a plurality of prepregs bonded together, (c) placing the resulting laminate from step (b) between both press plates of a press machine, (d) placing a polyamide film having a melting point equal to or higher than 170.degree. C. between the exposed side of the both-side roughened copper foil of the laminate and a press plate, (e) pressing the laminate with the press plates of the press machine at a temperature of 170.degree. C. or higher, a pressure of 10 kgf/cm.sup.2 or higher for a time of 60 minutes or longer, (f) separating the laminate from the press machine and (g) peeling the polyamide film from the laminate to obtain the copper-clad laminated board.