Patent ID: 7378228

Claim:
A process of preparing a multilayered printed circuit board of buildup mode comprising the steps of: (i) coating onto a circuit substrate, on which a pattern has previously been fabricated, an insulating layer comprising a positive type photosensitive epoxy resin composition wherein the positive type photosensitive epoxy resin composition comprises (a) an epoxy resin having two or more epoxy groups in one molecule; (b) a modified phenolic resin having a triazine ring, (c) a latent basic curing agent, and (d) a photosensitive acid generator; (ii) drying the insulating layer at a temperature between about 60°-90° C.; (iii) irradiating the insulating layer imagewise with an active energy beam through a photomask; (iv) heat curing the insulating layer at a first temperature of between 95°-120° C. to cure unexposed areas; (v) dissolving exposed areas with a developer; (vi) additionally heat curing the insulating layer at a second temperature of between 130°-200° C.; (vii) subjecting the insulating layer to a roughening treatment; (viii) forming a conductor layer by electroless plating and/or electrolytic plating; (ix) adhering the conductor layer to the insulating layer; (x) coating onto the conductor layer another insulating layer comprising the positive type photosensitive epoxy composition; and (xi) repeating steps (ii) to (x) as necessary to produce the multilayer printed circuit board.