Polymer-based Cu/Ag composite as seed layer on insulating substrate for copper addition of multi-dimensional conductive patterns.

• A conductive polythiophene composite film containing copper and silver is formed. • Cu/Ag-PT film serves as seed layer to directly electrodeposit on insulating substrate. • A multi-dimensional conductive pattern is obtained by Cu/Ag-PT direct electroplating. Conductive polymer direct electroplating technology is one of the research hotspots in printed circuit board manufacturing. In this work, we designed a simple, efficient and environmental friendly chemical polymerization method to form a conductive polymer-based metal-mixed composite film where the polymer was polythiophene and the metals included copper and silver (PT-based Cu/Ag composite film). The work function of the PT-based Cu/Ag composite film decreased from 4.822 eV of pure PT to 4.638 eV, which serves as a seed layer to prepare conductive circuits by the additive process. The method without the metal etching and photolithography steps solves the problems of conventional subtractive processes for forming conductive patterns. Besides, the PT-based Cu/Ag composite film is able to increase the roughness of the substrate to improve the bonding force between the electroplated copper layer and the substrate. Moreover, due to the particularity of oxidation solution for preparing the PT-based Cu/Ag composite film, conductive lines and patterns can be selectively formed on insulating substrate with arbitrary shapes by the additive process. [Display omitted] [ABSTRACT FROM AUTHOR]