Electrolytic or electroless gold depositions are used to provide a conductive and corrosion-resistant final coating for electronic applications. Because copper or copper alloys are the predominant choice for the base material, a nickel or nickel–phosphorus layer is often used as a diffusion barrier.
Comprehensive test results have been presented for a new and patented gold post-dip treatment that significantly improves the corrosion resistance of nickel/gold deposits and contributes to the reduction of gold costs. Extended NAV testing, to two times the ASTM B-735 standard, shows a significant increase in corrosion resistance for a 0.3 µm gold thickness.
This article, provided by Atotech Deutschland, will demonstrate that the Betatec post-dip can impart beneficial hydrophobic properties to the gold surface with subsequent blocking of pores. This hydrophobic and protective mechanism has been evaluated by water contact angle measurements on pure copper, nickel, and gold deposits together with nickel/gold plating on copper—before and after treatment with the gold post-dip.