METHOD OF MANUFACTURING FOR PRINTED WIRING BOARD

摘要

A manufacturing method of a printed circuit board is provided to obtain a circuit pattern of a fine pitch having a flat surface by preventing etching of a circuit surface in a peeling process of a photoresist layer. A conductive underlying layer(23) is formed on a surface of an insulation board(10). A photoresist layer(31) is formed on a surface of the underlying layer. A concave part(33A) is formed by patterning a resist pattern(33) on the photoresist layer. The concave part exposes the underlying layer. A copper plating layer(24) is formed on the underlying layer exposed by the concave part by using a PPR(Periodic Pulse Reverse) plating method. A circuit pattern is formed by successively removing the photoresist layer and the underlying layer. A pitch of the circuit pattern is less than 30um.