温度对浸镀锡镀层的影响

Effect of Plating Temperature on Immersion Tin Coating

在基于氯化胆碱-水溶液(ChCl-H2O)的浸镀锡溶液中,以铜片为基材,在不同温度下进行浸镀锡研究。分别利用X-荧光光谱仪、扫描电子显微镜、X-射线衍射仪、可焊性测试仪和电化学工作站,考察了浸镀锡速率、形貌、物相和性能受温度的影响程度。结果表明,随着温度的升高,浸镀锡的沉积速率不断加快,浸镀锡镀层的耐蚀性和可焊性均有提高;镀层表面在较低温度时光亮平整,但随温度上升,变得越来越粗糙;在70°C时,锡镀层的晶相组成由Sn和Cu6Sn5两相共存转变Sn、Cu6Sn5和Cu3Sn三相共存。在ChCl-H2O体系中,铜基浸镀锡的反应活化能Ea为24.6kJ·mol-1。

The present study documents the effect of electroless plating temperature on the deposition rate, morpholo- gy, structure and performance, such as solderability and corrosion resistance, of Sn coatings on Cu substrate achieved from ChCl-H2O solution by immersion deposition. The effects were investigated by X-ray spectroscopy, scanning e- lectron microscope, X-ray diffraction, solderability tester and electrochemical workstation, respectively. The results showed that the deposition rate, corrosion resistance and the solderability of the immersion Sn coatings increased with the increasing temperature, the surface was smooth and bright at lower temperature, but turned to be rougher and rougher with the increasing temperature, the Cu-Sn intermetallic phase varied from Cu5sSn5 to Cu3 Sn coexisting with Cu6Sn5 at the temperature above 70℃. The activation energy of Sn deposition Ea was calculated to be 24. 6 kJ· mol^-1.