Patent ID: 7208062

Claim:
A process of making a laminated circuit board, comprising laminating a circuit board with an adhesive film, wherein: said adhesive film is formed by laminating a resin composition layer comprising a layer A and a layer B on a support base film; wherein: layer A is a layer of a thermosetting resin composition which comprises an epoxy resin having two or more epoxy groups in one molecule and an epoxy curing agent, and has an inorganic filler content of less than 40% by weight, and after thermal curing has a cured surface that, which after roughening with an alkaline permanganic acid solution, allows forming a conductor layer by plating, and is solid at ambient temperature; layer B is a layer of a thermosetting resin composition that comprises an epoxy resin having two or more epoxy groups in one molecule, an epoxy curing agent, and an inorganic filler, selected from the group consisting of silica and alumina, in an amount of more than 40% by weight, and is solid at ambient temperature; said layer A is laminated adjacent to said support base film; said resin composition layer or said layer B, under lamination conditions, has a fluidity capable of filling a resin in a through hole and/or a via hole simultaneously with laminating said circuit board; and said laminating of said circuit board with said adhesive film is carried out while keeping said layer B directly in contact with said circuit board, wherein said support film is removed prior to any roughening.