Patent ID: 6866739
Filing Date: 2005-03-15
Classification: B32B,H05K,Y10S,Y10T

Abstract:
1. The method of producing a circuit sheet for a multi-layer wiring board comprising: providing a transfer sheet comprising a metal foil adhered to a resin film; working said metal foil into a circuit pattern by a resist method thereby to prepare a wiring/circuit layer on said transfer sheet; press-adhering said transfer sheet onto the surface of an insulating sheet of a half-cured thermosetting resin in a manner that the wiring/circuit layer faces the surface of the insulating sheet; and peeling off the resin film of the transfer sheet in order to obtain a circuit sheet having the wiring/circuit layer transferred onto the surface of the insulating sheet in a manner of being buried therein, wherein said metal foil is adhered to said resin film with an adhesive obtained by crosslinking an acrylic polymer obtained by the copolymerization of a (meth)acrylic acid ester with a carboxyl group-containing radically polymerizable monomer, with a polyfunctional compound having a functional group reactive with the carboxyl group: and said adhesive has a storage modulus of shearing elasticity G′ of not smaller than 2×10