Patent ID: 7144817

Claim:
A method for etching a resin layer, comprising: forming a film-like resin layer based on a polyimide having an imidation degree of from 50 to 98%; providing a resist layer having an opening at a position on a surface of the resin layer; bringing an etching solution at 65° C. or more into contact with the resin layer located at a bottom of the opening to etch the resin layer, wherein the etching solution comprises 3 to 65% by weight alcohol, 10 to 55% by weight alkali compound, and water in a weight of 0.75 to 3.0 times a weight of the alkali compound, and wherein the alcohol comprises at least one selected from the group consisting of a diol containing from 3 to 6 carbon atoms and a triol containing from 4 to 6 carbon atoms, and wherein the alkali compound comprises at least one selected from the group consisting of an alkali metal hydroxide and a quaternary ammonium hydroxide; then separating the resist layer from the resin layer; and imidating the polyimide of the resin layer.