Patent ID: 6015651
Filing Date: 2000-01-18
Classification: C08F,C08G,G03F,H05K

Abstract:
A method of forming a resist pattern comprising, in the following order:a) providing a method comprising a photo-polyinerizable resin (A), a photo-polymerization initiator (B) and a diluent (C), wherein the photo-polymerizable resin (A) is prepared by:reacting a novolak-epoxy resin (I) with (meth)acrylic acid (II) to introduce (meth)acryloyl groups into the epoxy resin (I) by the reaction between carboxyl group in (meth)acrylic acid (II) and epoxy group in the epoxy resin (I); and combining two or more resulting products to increase the molecular weight of said photo-polymerizable resin (A) by reacting two or more functional groups in a chain-extenision agent (III) reactable with the epoxy groups remaining in the resulting products,said chain-extension agent (III) being selected from the group consisting of polyhydric phenols having two or more phenol groups, polybasic acids having two or more carboxyl groups, and polyhydric thiols having two or more thiol groups; and wherein the reaction between said chain-extension agent (III) and the epoxy group remaining in the resulting products is carried out at 80 to 130.degree. C. in the presence or absence of diluent (C) and in the co-presence of a polymerization inhibitor and a reaction catalyst;b) applying said solder resist in composition on a printed circuit board;c) heat-drying said solder resist ink composition and forming a tack-free photoresist layer on the board;d) laminating a photomask onto said photoresist layer;e) exposing said photoresist layer through said photomask to cure an exposed portion thereof; andf) peeling off the photomask and developing the photoresist layer by removing a non-exposed portion thereof.