Communication-A Cyanide-Free Electrolyte for Hard Gold (Au-Co) Electrodepositing Utilizing DMH as Complexing Agent

A novel cyanide-free electrolyte was reported for Au-Co alloy electrodepositing. Firstly, an optimized electrolyte for Au-Co alloy electrodepositing was obtained from orthogonal experiment. By using optimized electrolyte, a desirable hard gold layer was obtained, which has a similar surface morphology, thickness and a comparative hardness to PCB bonding finger hard gold film. Then, XRD analysis revealed electrodeposits from the cyanide-free system performed supersaturated cobalt dissolved into gold crystal lattice and grew preferentially on Au (111). In summary, the electrolyte would have an extensive application in hard gold cyanide-free electroplating. (C) 2018 The Electrochemical Society.