| abstract |
An object of the present invention is to provide an adhesive composition for a printed wiring board which exhibits good heat resistance. Another object of the present invention is to provide: a coverlay for a printed wiring board using the adhesive composition for a printed wiring board; a copper-clad laminate; and a printed wiring board. The present invention provides an adhesive composition for printed wiring boards in which a siloxane-modified polyimide having structural units represented by formulae (1) and (2), an epoxy resin and an inorganic A filler, and wherein the weight average molecular weight (Mw) of the siloxane-modified polyimide is 25,000 to 150,000 (inclusive), and relative to 100 parts by mass of the siloxane-modified polyimide , the mixing amount of the inorganic filler is 10 parts by mass to 100 parts by mass (inclusive). In formulas (1) and (2), Ar represents a tetravalent aromatic tetracarboxylic acid residue; M represents a number from 0.35 to 0.75 (inclusive); n represents a number from 0.25 to 0.65 (inclusive); R 1 in (1) represents a divalent diamine siloxane residue; and R 2 in formula (2) represents a divalent aromatic diamine residue. |