In this work, the effect of thiourea on the initial stages of the Cu–Sn electrodeposition in the potential range of the underpotential deposition (UPD) of tin from the sulphate electrolyte was studied by linear sweep voltammetry. The mechanism of Cu–Sn alloy nucleation and growth was proposed based on the results of chronoamperometry, chronopotentiometry, and scanning electron microscopy. Thiourea in the concentrations of 0.001–0.010 g/L showed a significant inhibitory effect on the reduction of copper ions. Analysis of the current-time dependencies revealed that Cu–Sn deposition in the UPD region of tin from thiourea-containing solutions proceeds through 3D diffusion-controlled growth of copper clusters. The nucleation type and the main nucleation parameters were calculated based on the Scharifker and Hills theoretical model. Galvanostatic experiments proved that the UPD of tin occurs on the surface of initially formed copper clusters. Surface characterization of Cu–Sn coatings deposited in the presence of thiourea showed a good correlation with electrochemical experiments.

在这项工作中，通过线性扫描伏安法研究了硫脲对硫酸盐电解质中锡的欠电位沉积（UPD）电位范围内Cu-Sn电沉积初始阶段的影响。基于计时电流法，计时电位法和扫描电子显微镜的结果，提出了Cu-Sn合金成核和生长的机理。浓度为0.001–0.010 g / L的硫脲对铜离子的还原具有明显的抑制作用。对当前时间依赖性的分析表明，含硫脲溶液中锡的UPD区域中的Cu-Sn沉积是通过3D扩散控制的铜团簇生长进行的。基于Scharifker和Hills理论模型，计算了成核类型和主要成核参数。恒电流实验证明，锡的UPD发生在最初形成的铜簇的表面上。在硫脲存在下沉积的Cu-Sn涂层的表面特性与电化学实验显示出良好的相关性。