Electrodeposition of Sn–Ag–Cu ternary alloy from HEDTA electrolytes

The electrodeposition of Sn–Ag–Cu ternary alloy from HEDTA electrolytes has been investigated. Based on LSV analysis on a rotating Pt-RDE, HEDTA was found to substantially shift the onset deposition potential of Sn, Ag and Cu ions to negative values and bring the LSV curves of the individual metals close together. A near-eutectic composition of Sn–Ag–Cu ternary alloy has been successfully achieved by HEDTA and simultaneously combining a small amount of thiourea as an auxiliary complexing agent. X-ray diffraction (XRD) confirmed that Sn, Cu6Sn5 and Ag3Sn phases were present in the deposit of Sn–Ag–Cu ternary alloy. Alkylpolyglucoside (APG) was found to be a suitable additive for the electrodeposition of Sn–Ag–Cu alloy. SEM image shows that the addition of alkylpolyglucoside produces a smooth, fine-grained and compact Sn–Ag–Cu deposit. ► Sn–Ag–Cu ternary alloy deposits were prepared by electrodeposition. ► HEDTA was developed as an effective complexing agent for the electrodeposition of Sn–Ag–Cu alloy. ► Alkylpolyglucoside was found to be an additive suitable for the electrodeposition of Sn–Ag–Cu alloy. ► The effects of complexing agents and additive were investigated by LSV, EIS, XRD and SEM.