MANUFACTURE OF MULTILAYER WIRING BOARD

PURPOSE:To eliminate the partial disconnection of a viahole of small diameter by a method wherein etching is carried out before a plating resist is removed. CONSTITUTION:A plating resist 1 whose pattern is opposite to that of a circuit is formed on a conductor 3 of a substrate provided with a plated through-hole. A plating 2 such as a solder plating is deposited on the circuit and the through- hole, etching is executed, and the plating resist 1 is separated. A circuit is formed through etching. As an etching process is carried out as a pre-treatment, a bitten part 5 is provided to the conductor 3 in the pre-treatment to partially disconnect it, and when the circuit is formed after the resist is removed, the partially disconnected bitten part 5 can be formed into a fully disconnected part 6 within a prescribed etching process time.