Patent ID: 8546066

Claim:
A method for forming a conductor pattern by a subtractive method, which consists essentially of the steps of (a) forming a photo-crosslinkable resin layer having a thickness of 15 to 100 μm on a substrate provided with a conductive layer on its surface by using a negative type dry film resist, (b) treating the photo-crosslinkable resin layer with an alkali aqueous solution to render it thinner to adjust the thickness of the photo-crosslinkable resin layer to 0.05 to 0.9 times the thickness it had before the treatment, (c) carrying out exposure for a circuit pattern, (d) developing, and (e) etching, the steps included in this order, wherein the alkali aqueous solution is an aqueous solution containing 5 to 20 mass % of an inorganic alkaline compound, and the inorganic alkaline compound is at least one compound selected from alkali metal carbonate, alkali metal phosphate, alkali metal silicate and alkali metal sulfite.