Patent ID: 7947428

Claim:
A method for forming a photosensitive polyimide pattern on a metal conductor, comprising carrying out the following steps (A) to (E) in this order: (A) a step of forming an ester containing photosensitive polyimide precursor layer by applying an ester containing photosensitive polyimide precursor composition onto the metal conductor, wherein the ester containing photosensitive polyimide precursor composition includes photosensitive groups bonded via an ester bond; (B) a step of forming an ionically coupled photosensitive polyimide precursor layer by applying an ionically coupled photosensitive polyimide precursor composition onto the ester containing photosensitive polyimide precursor layer, wherein the ionically coupled photosensitive polyimide precursor composition includes photosensitive groups coupled via an ionic bond; (C) a step of exposing to transfer a mask pattern as a latent image onto the ester containing photosensitive polyimide precursor layer and the ionically coupled photosensitive polyimide precursor layer; (D) a step of developing the photosensitive polyimide precursor layers; and (E) a step of forming a polyimide pattern by curing the developed ester containing photosensitive polyimide precursor layer and ionically coupled photosensitive polyimide precursor layer.