Acceleration Effects of Hydroxylamine Sulfate on Electroless Gold Plating on Ni–Pd Surfaces

摘要

Hydroxylamine sulfate (HAS) was used to accelerate Au deposition following the covering of a Ni–Pdsubstrate with Au layer. The influence of HAS on the electroless gold plating bath and depositionprocedure was investigated. The acceleration mechanism, nucleation mechanism, and corrosionresistance were analyzed via electrochemical methods. The surface microtopography and the chemicaland phase compositions of Au layers were also characterized. Results showed that HAS did not affectthe stability of the plating bath because of the reaction of cyanide and hydroxylamine. HAS alsopositively accelerated Au deposition due to its excellent catalyzed oxidation on the Au surface. As theoptimum concentration, 0.02 M HAS increased the deposition rate by 70%. At the same deposition time,the transformation of the nucleation model increased the size of Au grains and smoothened the surfaceof the Au layer after the addition of 0.02 M HAS.