PURPOSE: To eliminate the generation of a pinhole in a formed resin layer by coating the surface of a substrate with a specific liquid composition by a printing method and subsequently repeating a process for the irradiation with active rays to form a thermosetting solid resin layer.
CONSTITUTION: A liquid composition is prepared by compounding an epoxy resin, a polymerizable compound containing a polyfunctional (meth)acrylate polymerizable compound as at least a part of polymerizable components, a curing agent for the epoxy resin and a photopolymerization initiator for the polymerizable compound. This liquid composition is applied to the surface of a substrate by adapting a printing method and repeatedly irradiated with active rays to form a thermosetting solid resin layer to the surface of the substrate. It is pref. to further perform heat treatment after the formation of the thermosetting solid resin layer. Further, as a pref. embodiment of the substrate, there is a printed wiring board.
OGITANI OSAMU
SHIRASE TORU
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