Method of producing conductor circuit boards

Abstract

A thin metal layer with a thickness of 1 to 5 .mu. is formed electrolytically (S2) on an electrically conductive single-plate substrate having a predetermined roughness, a resist mask is formed (S3) on the surface of the thin metal layer, and a conductor circuit is then electroformed thereon (S4) using copper. After the surface of the conductor circuit is roughened (S5), the conductor circuit, along with the single plate and the interposed thin metal layer, is stacked on an insulating substrate for lamination, and the individual layers are adhered integrally to one another by the application of heat and pressure (S7). Then, the single plate only is peeled off (S8), and the exposed thin metal layer is removed by etching (S9). The thin metal layer and the conductor circuit are electroplated under high-speed conditions including a solution contact speed of 2.6 to 20 m/sec and a current density of 0.15 to 4.0 A/cm.sup.2, so that a required adhesion force can be obtained between the thin metal layer and the resist mask, and the conductor circuit can be made as flexible as rolled annealed copper. Thus, very thin, high-density conductor circuits can be produced which, having a thickness of 10 .mu.m or less, are adapted not only for rigid printed wiring boards but also for flexible printed wiring boards.

Dependencies are inferred from the claim text.