Preparation and characterization of negative photosensitive polysiloxaneimide

A photosensitive polysiloxaneimide precursor was synthesized from oxydianiline, bis( p ‐aminophenoxy)dimethylsilane, and a diacid chloride. This diacid chloride was prepared by the reaction of thionyl chloride with a diacid, which resulted from the reaction of pyromellitic dianhydride with hydroxyethylacrylate in N ‐methylpyrrolidone (NMP). The adhesion properties between polyimide and substrates such as SiO 2 wafer were improved with introduction of siloxane moiety into the polyimide chain. The dielectric constant decreased with increasing siloxane moiety content. The photocrosslinking reaction results show that an 88–90% gel fraction was reached under the irradiation of a high‐pressure mercury lamp. © 1995 John Wiley & Sons, Inc.