Abstract: An objective of this invention is to provide an interlayer dielectric film with a carrier material used in a multilayer printed circuit board, which exhibits sufficient rigidity for a thin multilayer printed circuit board. According to the present invention, there is provided an interlayer dielectric film with a carrier material comprising a carrier material comprised of a metal foil or resin film and an interlayer dielectric film formed on one side of the carrier material, wherein the interlayer dielectric film is comprised of a base material impregnated with a resin; the base material has a thickness of 8 ?m to 20 ?m; and when the resin is cured at 170° C. for one hour under a pressure of 30 kgf/cm2, an elongation percentage of the interlayer dielectric film in a planar direction is 0.05% or less as determined by a TMA method.

Abstract: An objective of this invention is to provide an interlayer dielectric film with a carrier material used in a multilayer printed circuit board, which exhibits sufficient rigidity for a thin multilayer printed circuit board. According to the present invention, there is provided an interlayer dielectric film with a carrier material comprising a carrier material comprised of a metal foil or resin film and an interlayer dielectric film formed on one side of the carrier material, wherein the interlayer dielectric film is comprised of a base material impregnated with a resin; the base material has a thickness of 8 ?m to 20 ?m; and when the resin is cured at 170° C. for one hour under a pressure of 30 kgf/cm2, an elongation percentage of the interlayer dielectric film in a planar direction is 0.05% or less as determined by a TMA method.

Abstract: An insulating adhesive for a multilayer printed circuit board, which is to be laminated to an internal layer circuit board coated with an undercoating agent comprising an epoxy resin and a curing agent therefor, and which comprises as essential components:(a) a bisphenol type epoxy resin or phenoxy resin having a weight average molecular weight of at least 10,000,(b) a bisphenol type epoxy resin having an epoxy equivalent of not more than 500, and(c) an epoxy resin curing agent, said insulating adhesive being excellent in storage stability in the form of a varnish or as coated on a copper foil, and when coated on an internal layer circuit board coated with an undercoating agent, being able to be well integrally cured with the undercoating agent.

Abstract: A process for producing a multilayer printed circuit board which comprises coating a light and heat curable undercoating agent on an internal layer circuit board, irradiating the undercoating agent with active energy beams to make the same tack-free, then laminating thereto a metal foil having an insulating adhesive layer and subsequently heating the resulting assembly to integrally cure the same. When the undercoating agent is coated on an internal layer circuit board and irradiated with a light to be made tack-free, and thereto is laminated a copper foil having a thermosetting insulating adhesive by a rigid roll or the like, the undercoating agent is softened or fluidized and the surface is smoothened. When the resulting laminate is thereafter heated, the undercoating agent coated on the internal layer circuit board and the insulating adhesive coated on the copper foil are integrally cured.

Abstract: An undercoating agent for a multilayer printed circuit board which comprises:(a) a normally solid epoxy resin having a softening point of 45.degree. to 120.degree. C.,(b) an epoxy resin curing agent,(c) a diluent in which the epoxy resin is dissolved and which consists of a photopolymerizable monomer, and(d) a photopolymerization initiator,said undercoating agent being effectively used in the production of a multilayer printed circuit board which utilizes making the undercoating agent tack-free by irradiation with active energy beams and the main curing of the undercoating agent by heating.