| 摘要 |
A manufacturing method of printed wiring substrate capable of manufacturing wiring of which the surface of the cross section in the width direction is flat even the pitch of wiring is very fine is provided. The method is comprised of: forming an underlayer (23) on a surface of an insulation substrate (10); forming a photoresist layer (31) on the surface of the underlayer (23) and forming a recess (33A) for exposing the underlayer (23) in the photoresist layer (31) by a patterning process of exposing and developing a predetermined pattern; forming a copper plating layer (24) on the underlayer (23) in the recess (33A); peeling off the patterned photoresist layer (31); and forming a wiring pattern by removing the part of the underlayer (23) which is exposed by the peeling of the photoresist layer (31), wherein the copper plating layer is formed by PPR(Periodic Pulse Reverse) plating method, the PPR plating method using a plating solution in which the concentration of copper sulfate pentahydrate is 50 to 90g/L and the concentration of sulfuric acid is 180 to 210g/L, and setting the current density ration of applied pulse in a range of positive: negative = 1: 2. 2 to 1: 1. 8 as a plating condition. |
