tert-Butylamine borane as a reductant in electroless nickel plating for improved etch resistance in the electrolyte

An Ni-B coating was developed on a copper substrate by the direct electroless technique and from a plating bath containing tert-butylamine borane (TBAB). The influence of the electroless plating conditions, using TBAB as a reducing agent on the composition, surface morphology, high-temperature stability and etch resistance in the electrolyte of the coatings, was investigated. The resulting electroless Ni-B plating surfaces were examined and characterized by scanning electron microscopy and X-ray fluorescence spectroscopy for morphology and chemical composition, respectively. Electrochemical characterization by potentiodynamic polarization confirmed that a 0.1 M nickel concentration bath for the Ni-B plating was optimized by a TBAB concentration of 0.03 M, temperature of 60 degrees C and pH of 8. Under the optimal bath conditions, the Ni-B electroless plating layer exhibited superior etch resistance in the electrolyte as well as improved stability at high temperature than the Ni-B electroless plating layer prepared using dimethylamine borane. Hence, owing to the remarkable properties of the Ni-B electroless plating layer, this fabrication technique that employs TBAB can be extended to fabricate other Ni-B electroless plating layers.