印刷电路板铜电路表面化学镀镍前预镀镍替代无钯活化

摘要

The electroless nickel plating on copper patterns of printed circuit board was conducted after electroless nickel pre-plating. The effects of mass concentrations of reductant and complexant, pH and temperature on the incubation time for electroless nickel pre-plating and the thickness of electrolessly pre-plated nickel coating were studied. The optimal bath composition and operation conditions for electroless nickel pre-plating were obtained as follows: NiSO4·7H2O 40 g/L, H3BO330 g/L, NH4Cl 30 g/L, triammonium citrate 30 g/L, dimethylaminoborane (DMAB) 3 g/L, temperature 60 ℃, pH 9.0, and time 3 min. The electrolessly plated nickel coating obtained after pre-plating under the optimal conditions features a qualified adhesion to the substrate and an appearance similar to that obtained after traditional palladium activation, but the former has a more compact structure and better corrosion resistance as compared with the later.%在印刷电路板的铜电路表面化学预镀镍后再进行化学镀镍,研究了预镀镍溶液中还原剂质量浓度、配位剂质量浓度、pH和温度对预镀镍开始所需时间和预镀镍层厚度的影响,获得较优的预镀镍配方和工艺条件为:NiSO4·7H2O 40 g/L,H3BO330 g/L, NH4Cl 30 g/L,柠檬酸铵30 g/L,二甲胺基硼烷(DMAB)3 g/L,pH 9.0,温度60 ℃,时间3 min.在最佳条件下预镀镍后进行化学镀镍所得镀层的结合力合格,外观与钯活化后化学镀镍所得镀层相差不大,但其晶粒更细致,耐蚀性更优.