Method for manufacturing a circuit board

Abstract

According to the present invention, a circuit board having a further-microfabricated circuit pattern that can be manufactured in further simplified steps is obtained. For such purpose, a mold 10, which has protrusions 11 formed in a pattern corresponding to a circuit pattern, is used to apply a conductive material layer (metal paste) 13 to head portions of the protrusions 11 of the mold 10. The mold is heat- and pressure-welded to the surface of a substrate 20 that is made of a resin film or the like. Accordingly, a pattern comprising the protrusions 11 and the conductive material layer (metal paste) 13 are transferred to the substrate 20. After transfer, the resin substrate (resin molding 30) is immersed in a copper sulfate plating bath for electrolytic plating treatment. Copper ions in the plating bath were deposited inside each recess 31 while the conductive material layer 13 is used as a base material for the formation of a metal wiring 32. A pattern of the recesses 31 transferred to the substrate-20 side is determined depending on a pattern comprising the protrusions 11 on the mold 10. Thus, a microfabricated high-density circuit pattern formed with metal wirings 32 having arbitrary aspect ratios can be obtained.

Dependencies are inferred from the claim text.