Ester group-containing poly (imide-azomethine) copolymer, ester group-containing poly (amide acid-azomethine) copolymer, and positive photosensitive resin composition

摘要

Provided are an ester group-containing poly(imide-azomethine)copolymer having low linear thermal expansion coefficient; a production method thereof; an ester group-containing poly(amide acid-azomethine)copolymer to serve as the precursor of the poly(imide-azomethine)copolymer; a positive photosensitive composition including the poly(amide acid-azomethine)copolymer and a photosensitizer; a method for forming a fine pattern of an ester group-containing poly(imide-azomethine)copolymer from the composition; and a method for forming a fine pattern of an ester group-containing poly(imide-azomethine)copolymer by etching a photosensitizer-free, ester group-containing poly(imide-azomethine)copolymer in an alkaline solution. The ester group-containing poly(imide-azomethine)copolymer comprises an ester group-containing azomethine polymer unit of the formula (1) and an imide polymer unit of the formula (2): wherein in the formulas (1) and (2), A and D are each independently a divalent aromatic or aliphatic group with D containing an ester group; and B is a tetravalent aromatic or aliphatic group.