Patent ID: 8143533

Claim:
A method for producing a circuit board, comprising the steps of: (a) preparing an insulating substrate having a through-hole(s), which has a first conductive layer on a first surface, on a second surface opposite to the first surface and on an inner wall of the through-holes(s); (b) covering the first conductive layer and an opening of the through-hole(s) on the first surface with a photocrosslinkable resin layer and a mask layer by forming the photocrosslinkable resin layer and the mask layer on the first surface; (c) uncovering the first conductive layer on the periphery of the through-hole(s) on the first surface by supplying a photocrosslinkable resin layer removing solution from the second surface and removing the photocrosslinkable resin layer on the through-hole(s) and on a periphery of the through-hole(s) on the first surface; (d) subjecting the photocrosslinkable resin layer on the first surface to pattern exposure; (e) covering the first conductive layer and an opening of the through-hole(s) on the second surface with a photocrosslinkable resin layer and a mask layer by forming the photocrosslinkable resin layer and the mask layer on the second surface; (f) removing the mask layer on the first surface; (g) uncovering the first conductive layer on the first surface and the first conductive layer on a periphery of the through-hole(s) on the second surface by supplying a photocrosslinkable resin layer removing solution from the first surface and removing an uncured photocrosslinkable resin layer on the first surface and the photocrosslinkable resin layer on the through-hole(s) and on the periphery of the through-hole(s) on the second surface; (h) subjecting the photocrosslinkable resin layer on the second surface to pattern exposure; (i) removing the mask layer on the second surface; (j) uncovering the first conductive layer on the second surface by supplying a photocrosslinkable resin layer removing solution from the second surface and removing an uncured photocrosslinkable resin layer on the second surface; (k) forming a second conductive layer on the first conductive layer uncovered on the inner wall of the through-hole(s) and the periphery of the through-hole(s) and on the first surface and the second surface by electrolytic plating; (l) uncovering the first conductive layer on the first surface and the second surface by removing the cured photocrosslinkable resin layers on the first surface and the second surface; and (m) removing the uncovered first conductive layer by flash etching.