Abstract: A plurality of wiring traces and a plurality of lead wires for plating are formed on a base insulating layer. Each wiring trace and each lead wire for plating are integrally formed with each other. An electrode pad is provided at an end of each wiring trace, and the lead wire for plating is provided to extend from each electrode pad toward the opposite side to the wiring trace. A width of each lead wire for plating is set larger than a width of each wiring trace.

Abstract: In a roll-to-roll step, an adhesive solution is applied to a release film 1 including a polyethylene terephthalate film and this film 1 is passed through a drying oven 500 regulated to 60 to 150° C. to thereby form an adhesive layer 2. Subsequently, an insulating film 3 including a polyimide film is laminated on the adhesive layer 2 at room temperature (about 25° C.) to thereby produce a layered product 6 including the release film 1, adhesive layer 2 and insulating film 3. Next, the release film 1 is stripped from the layered product 6 and a conductor film 4 including a copper foil is laminated to the adhesive layer 2 to thereby produce a conductor-clad laminate 8.