Sumitomo Bakelite Company Limited

Tomoyoshi Honjoya

Takeshi Hosomi

Toyoaki Kishi

Masahiro Mitsui

Sei Nakamichi

Akihiko Tobisawa

Flame-retardant resin composition and prepreg and laminate using the same

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:

Insulating adhesive for multilayer printed circuit board

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. Since the insulating adhesive coated on the metal foil keeps the thickness, a multilayer printed circuit board having an excellent board thickness precision can be produced without depending on the percentage of the remaining copper foil in the internal layer.

Process for producing multilayer printed circuit board

An undercoating agent for a multilayer printed circuit board which comprises:

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Fujieda, Japan

Tomoyoshi Honjoya