Effect of electrodeposition parameters on chemical and morphological characteristics of Cu-Sn coatings from a methanesulfonic acid electrolyte

Currently Cu-Sn coatings are widely used in numerous commercial productions in replacement of Ni layers especially for decorative arts. In recent decades, researchers are exploring more environment-friendly baths to deposit Cu-Sn coatings to substitute CN− electrolyte which has been widely used as conventional electroplating baths for industrial applications. This paper investigated Cu-Sn deposition from a methanesulfonic acid based bath studying the optimization of deposition parameters. Film composition was varied by changing current density, which leads to a difference in color and final properties. Usually lifetime of tin containing baths is limited because the composition of deposited films has poor stability. In this work the effect of deposition parameters and anode materials on bath and deposits stability is evaluated. In particular, the application of pulse current was considered to improve the quality of coatings at fixed duty cycle while deposition frequency was varied. The coatings deposited under different conditions were compared in term of microstructure and corrosion behavior.