In this study, a cyanide-free electrolyte containing glutamate as a complexing agent is investigated as a more environmentally friendly alternative for alkaline copper plating. The solution was prepared using copper sulfate, sodium glutamate and potassium hydroxide. The pH of the electrolyte (pH = 8) and the ratio ligand:copper (R = 3), were chosen from equilibrium diagrams in order to avoid the formation of insoluble complexes and oxides. The electrochemical response of the system was determined by means of cyclic voltammetry. The results showed that copper electroreduction occurs in a two steps pathway with a cuprous-glutamate complex as an intermediate. Galvanostatic deposits obtained from the bath under study had proper brightness and roughness at the selected current density conditions. Scanning electron microscopy and X-Ray diffraction were carried out in order to characterize deposits surface morphology and crystal orientation. Chronoamperometric experiments together with atomic force microscopy proved that copper deposits grow through an instantaneous nucleation mechanism in which nuclei are not exactly spherical. These preliminary studies suggest that the Cu +2 -glutamate electrolyte may be suitable for the replacement of cyanide baths in copper electrodeposition at high pH without the need of additives as this electrolyte acts as a self-levelling system. Also, the use of this electrolyte could eliminate the need of performing strike deposits on less noble substrates, allowing a one step plating process.

Deposition of Cu-Sn alloys from a methanesulfonic acid electrolyte containing small amounts of benzyl alcohol was investigated. Polarisation experiments (cylic and linear sweep voltammetry) were carried out using a rotating disc electrode to identify the reduction and dissolution processes that take place in the system and to determine the effect of the solution constituents on them. Potentiostatic deposition was performed onto a rotating cylinder electrode and the resulting deposits were charactised using SEM and XRD. The results showed that co-deposition of copper and tin is possible even at potentials less cathodic than tin discharge potential. The latter was attributed to the underpotential deposition of Sn 2+ on a copper substrate. Smooth and compact deposits were obtained at various deposition potentials and Cu 2+ concentrations, with Sn contents between 1.6 -62.4 wt.%. Several stable phases, such as pure copper, a-CuSn, e-Cu 3 Sn and h 0 -Cu 6 Sn 5 phase, were detected at different operating conditions. Finally, it was found that BA increases the amount of tin in the deposit when Cu 2+ concentrations in the solution is kept low, especially at high overpotentials. This additive also inhibits the formation of dendrites and reduces surface roughness.