Patent ID: 8182729
Filing Date: 2012-05-22
Classification: B29C,B32B,H05K

Abstract:
1. A method of making a wiring board having an electrically insulating substrate and a wiring pattern formed in the substrate in a multilayer manner, the method comprising: stacking a plurality of base films in a predetermined direction to form a stacked film structure, each base film including at least one thermoplastic resin film; and applying a first pressure and a first heat to the stacked film structure from both sides in a stacked direction so that the plurality of base films is joined together to form the electrically insulating substrate, wherein at least one of the plurality of base films is a combined film including two thermoplastic resin films and a fiber sheet sandwiched between the thermoplastic resin films in such a manner that air space remains in the fiber sheet, and the applying of the first pressure and the first heat comprises heating the combined film to a predetermined temperature, which is equal to or greater than a temperature at which the thermoplastic resin films are hydrolyzed, to soften the thermoplastic resin films of the combined film and to eliminate the air space from the fiber sheet of the combined film by filling the air space with the softened thermoplastic resin films.