Abstract: A polyimide copolymer represented by formula (I) or formula (II) is provided. In formula (I) or formula (II), B is a cycloaliphatic group or aromatic group, A is an aromatic group, R is hydrogen or phenyl, and m and n are 20-50. The invention also provides a method for fabricating a patterned metal oxide layer.

Abstract: A thermally curable solder resist composition for a flexible printed circuit board is provided. The solder resist composition includes (a) 50-100 parts by weight of an epoxy resin, wherein the epoxy resin includes at least an aliphatic polyester modified epoxy resin having formula (I) or (II), in which, each of R1 and R2, independently, is a C6-38 saturated or an unsaturated carbon chain, R3 is ether, phenyl, a C6-38 heterocyclic or C6-38 saturated carbon chain, n is an integer of 1-10 and the aliphatic polyester modified epoxy resin had a molecular weight of 1000-5000; (b) 1-10 parts by weight of a curing agent; and (c) 1-10 parts by weight of a catalyst.

Abstract: A polyimide copolymer represented by formula (I) or formula (II) is provided. In formula (I) or formula (II), B is a cycloaliphatic group or aromatic group, A is an aromatic group, R is hydrogen or phenyl, and m and n are 20-50. The invention also provides a method for fabricating a patterned metal oxide layer.

Abstract: A thermally curable solder resist composition for a flexible printed circuit board is provided. The solder resist composition includes (a) 50-100 parts by weight of an epoxy resin, wherein the epoxy resin includes at least an aliphatic polyester modified epoxy resin having formula (I) or (II), in which, each of R1 and R2, independently, is a C6-38 saturated or an unsaturated carbon chain, R3 is ether, phenyl, a C6-38 heterocyclic or C6-38 saturated carbon chain, n is an integer of 1-10 and the aliphatic polyester modified epoxy resin had a molecular weight of 1000-5000; (b) 1-10 parts by weight of a curing agent; and (c) 1-10 parts by weight of a catalyst.

Abstract: A thermally curable solder resist composition for a flexible printed circuit board is provided. The solder resist composition includes (a) 50-100 parts by weight of an epoxy resin, wherein the epoxy resin includes at least an aliphatic polyester modified epoxy resin having formula (I) or (II), in which, each of R1 and R2, independently, is a C6-38 saturated or an unsaturated carbon chain, R3 is ether, phenyl, a C6-38 heterocyclic or C6-38 saturated carbon chain, n is an integer of 1-10 and the aliphatic polyester modified epoxy resin had a molecular weight of 1000-5000; (b) 1-10 parts by weight of a curing agent; and (c) 1-10 parts by weight of a catalyst.

Abstract: The present invention relates to a positive-working photosensitive composition comprising a partially diazonaphthoquinone (DNQ) capped polyamic ester with a capping level of about 5-80 molar %; a photosensitive agent and a solvent. The composition shows a high photosensitivity and leaves a relief pattern with high resolution and low dark film loss.