印制线路板上硫氰酸亚金钾体系化学镀金

Electroless gold plating on printed circuit board in potassium gold(Ⅰ) thiocyanate bath

以硫氰酸亚金钾[KAu(SCN)_2]为金源对镀镍印制线路板进行化学镀金。采用单因素试验研究了镀液中Au^+含量、硫氰酸铵含量、pH和温度对沉金速率、金层外观和结合力的影响,得到最优配方和工艺参数为:Au^+2.0 g/L,硫氰酸铵15 g/L,添加剂Cy-808 150 mL/L,pH 3.0,温度50℃。在此条件下沉金速率约为6 nm/min,结晶均匀细致,呈光亮的金黄色。

Electroless gold plating was conducted on the surface of nickel-plated printed circuit board using potassium gold（I） thiocyanate [KAu（SCN）2] as main salt. The effects of Au＋ and ammonium thiocyanate contents, as well as pH and temperature of the bath on deposition rate, appearance and adhesion of gold coating were studied by single-factor experiment. The optimal bath composition and process parameters were obtained as follows： Au＋ 2.0 g/L, ammonium thiocyanate 15 g/L, additive Cy-808 150 mL/L, temperature 50℃, and pH 3.0. The gold deposition rate under the given process conditions is ca.6 nm/min. The obtained gold coating is uniform, compact, bright and golden yellow.