Method for producing electrically conductive circuits on a base board

Abstract

A method is described for producing electrically conductive circuits on a print base board having a copper lamination attached on one side face thereof, and more particularly relates to such method for producing the circuits of excellent electrical conductivity by effectively utilizing a newly developed electrically conductive copper paste which is specifically adapted to metal plating, wherein at least two-layer circuits are formed on one side of the base board, of which a first-layer circuit having a plurality of electrodes and a second-layer circuit having a plurality of ring-shaped electrodes formed in connection with the electrodes of the first-layer circuits, each electrode of the second-layer circuit being defined by outer and inner circumferences with a central opening defined by the inner circumference, such that the metal plating applied to the electrodes of the first- and second-layer circuits with a predetermined thickness of the metal plating layer may provide an electrically conductive path between the two circuits including an elongated total length of the metal plating layer connected to the first-layer circuit, the metal plating layer having an enlarged sectional area to increase the electrical conductivity and to increase the adherence force of the second-layer circuit to the first-layer circuit.