ADHESIVE FOR COVERLAY FILM

摘要

PROBLEM TO BE SOLVED: To provide an adhesive for a coverlay film, which contains a polyvinyl acetal resin excellent in adhesion to the coverlay film.SOLUTION: The adhesive for a coverlay film is used for bonding the coverlay film to a flexible printed wiring board, and contains a polyvinyl acetal resin having a structural unit comprising an aromatic ring represented by the specified general formula (1), with the content of the structural unit comprising the aromatic ring represented by the specified general formula (1) being 40 mol% or less. In the formula (1), R represents a group comprising an aromatic ring.