Effect of Cd as a stabilizer in the electroless nickel plating system

Bath decomposition is a major problem in the electroless nickel (EN) plating system. Although the stabilization mechanism is far from being fully understood, bath stabilizers are normally added to extend the bath life in a viable EN plating solution. In this study, the effects of Cd²⁺ as a stabilizer on the plating rate, bath stability, and phosphorus content, corrosion resistance and microstructure of the deposits were investigated. The deposited films were examined using a scanning electron microscope (SEM) equipped with energy dispersive X-ray (EDX) spectroscopy and the X-ray photo spectroscopy (XPS). The electronic tunneling mechanism was used to elucidate the effect of the Cd²⁺ stabilizer on the plating system theoretically. The results calculated from theoretical method agreed well with the experimental data.