Patent ID: 7458150

Claim:
A method of producing a circuit board having a multilayer wiring pattern, the method comprising: forming a plurality of thermoplastic resin films, wherein the forming includes a step of forming a through-hole in each of the plurality of thermoplastic resin films, and a step of printing in which a conductive paste including metal nano-particles is supplied to each of the plurality of thermoplastic resin film such that each of the through-holes is filled with the conductive paste and, at the same time a wiring pattern is formed on each of the plurality of thermoplastic resin films; stacking the plurality of thermoplastic resin films after the forming step; and sintering the plurality of thermoplastic resin films after the stacking step; wherein in the sintering, the thermoplastic resin are pressed with heat at a low oxygen condition including alcohol such that the plurality of thermoplastic resin films are integrated and the metal nano-particles of the conductive paste are sintered.