Abstract: The method for forming wiring includes: laminating a thermosetting resin film and a metallic foil on an insulating substrate where base-layer wiring is formed, a mat surface of the metallic foil facing the resin film, pressing the film and the foil with application of heat; forming an opening in the metallic foil to expose a part of the insulating resin layer in which a via hole is to be formed; forming the via hole in the insulating resin layer by using as a mask the metallic foil; performing a desmear process of the via hole via the opening of the metallic foil; removing the metallic foil; forming an electroless-plated layer that covers the top surface of the insulating resin layer, a side surface of the via hole and a top surface of the base-layer wiring; and forming wiring including an electroplated layer on the electroless-plated layer.

Abstract: The method for forming wiring includes: laminating a thermosetting resin film in a semi-cured state and a metallic foil in this order on an insulating substrate where base-layer wiring is formed, a mat surface of the metallic foil facing the resin film, pressing the film and the foil with application of heat; forming an opening in the metallic foil so as to expose a part of the insulating resin layer in which a via hole is to be formed; forming the via hole in the insulating resin layer by irradiating high-energy beams on to insulating resin layer by using as a mask the metallic foil in which the opening is formed; performing a desmear process of the via hole via the opening of the metallic foil; removing the metallic foil by etching; forming an electroless-plated layer that continuously covers the top surface of the insulating resin layer, a side surface of the via hole and a top surface of the base-layer wiring corresponding to the bottom of the via hole; and forming wiring including an electroplated layer

Abstract: The laminated product in a structure including a glass-cloth contained resin layer according to this invention is a laminated product in which a wiring layer and an insulating layer alternately laminated are included and different wiring layers are electrically connected to each other by a via hole passing through the insulating layer, characterized in that at least one insulating layer 11 is formed of a laminated body including an insulating resin layer 7 on a lower wiring layer 5 and a glass-cloth contained resin layer 9 thereon, and in the laminated body, a via hole 17 continuously passes through from the upper glass-cloth contained resin layer 9 to the lower insulating resin layer 7.