Laminate for insulation protection of circuit boards

Abstract

A laminate comprising at least two layers of a photosensitive resin layer and a polyimide precursor resin layer; a process for formation of an insulating protective layer using a laminate which comprises laminating a laminate comprising at least photosensitive resin layer and a polyimide precursor resin layer on an insulating board having an exposed circuit; selectively exposing the photosensitive resin layer to active light; developing the resultant photosensitive resin layer; removing the exposed polyimide precursor resin layer by etching it with an alkaline solution using the photosensitive resin layer as a mask; removing the photosensitive resin layer; and then curing the residual polyimide precusor resin layer; and a process for preparation of a printed circuit which comprises forming a polymide precursor resin layer on an insulating board having an exposed circuit, patterning the resin layer with an alkaline solution, and then curing it. The laminate of this invention can provide extremely easily an insulating protective layer for circuits having a high processing precision and excellent in reliability on insulation. Further, a printed circuit having a high processing precision and excellent in reliability on insulation can be provided extremely easily by the processes of this invention.