An Electroless Copper Plating Process Using Glyoxylate as Reductant

An electroless copper plating process using glyoxylate as reductant was developed,structure and surface morphology of the deposit were also studied.The bath composition and operating conditions were:28.0 g/L CuSO4 · 5H2O,44.0 g/L EDTA · 2Na,10.0 mg/L α,α'-bipyridyl,10.0 mg/L potassium ferrocyanide,9.2 g/L glyoxylate,pH 11.5~12.5,temperature 40~50 ℃.Experimental results showed that:the electroless copper plating bath was quite stable;the copper deposition rate would increased in case of bath temperature and copper sulfate concentration increased;the bath stability would decreased due to lower activation energy of copper deposition in case of higher temperature;the qualified copper coating could be obtained only at a proper bath pH range of 11.5~12.5;the copper deposition rate would not be affected by concentrations of glyoxylate and complexing agent evidently,whereas excessive content of glyoxylate would cause the bath stability decreased;the copper coating had a FCC mixed crystal structure with blocky grains、pink/bright appearance and good ductility.