Formation of thin film circuits using preferential nucleation

Abstract

The binding energy for many metals on polymeric surfaces is dependent upon the degree of polymerisation of the substrate. It has been demonstrated for lead, tin, and silver that this difference can be made sufficiently great to allow images formed by electron or ultraviolet polymerisation to be developed by coating the entire substrate with metal; the metal adhering only to the developed portion of the polymer film. A thin layer of the polymer material is then deposited over the metal layer to form a reliable insulation film and the preferential nucleation process again used to form a second metal film pattern. Multilayer circuit patterns have been fabricated with resolution of several microns. The technique is compatible with conventional thin film evaporation techniques and should be suited for the fabrication of high density, multilayer circuits. © 1965.