Химическое осаждение пленок золота из растворов

Abstract

The processes of electroless and immersion gold plating from cyanoaurate solutions were investigated. It was shown that gold reduction with hypophosphite dissolved in the solution or with nickel and copper from the substrate is accompanied by the side processes of Ni or Cu dissolution owing to the reduction of hydrogen ions or the dissolved oxygen. This dissolution is provoked by the appearance of galvanic couples. The dissolved nickel and copper are partially codeposited with gold. These metals include in the near surface gold film zone and then they again take part in gold cementation or they catalyse the reaction of hypophosphite oxidation. Gold films are limited in thickness (0.1-0-3 mm) mainly owing to the adsorption of the gold cyanide in a trace quantity. The results of this investigation were used for working out the technology of electroless gold film plating.