化学镀锡反应动力学特性研究

Dynamic Characteristics of Electroless Tin Plating Reaction

目的研究化学镀锡反应过程的动力学特性。方法在硫脲-柠檬酸-酒石酸三元络合体系中,以次磷酸钠为还原剂,以Sn Cl2为主盐,在铜片上化学沉积锡镀层,研究温度、主盐、还原剂、H+和络合剂的浓度对沉积速度的影响规律。结果镀锡过程中,Sn2+,H+和次磷酸钠的反应级数分别为0.302,0.21和0.192;硫脲、柠檬酸和酒石酸的反应级数分别为0.237,0.213和0.081;速度常数为0.013,总反应级数为1.235级,表观活化能为11.184 k J/mol。结论建立了化学镀锡反应的动力学方程,对化学镀锡沉积工艺的选择和产物的控制具有一定的参考作用。

Objective To study the dynamic characteristics of electroless tin plating reaction. Methods Using sodium hypophosphite as the reducing agent, and SnC12 as the main salt, electroless Sn was deposited on copper in the thiourea-citric acid-tartaric acid trinary ligaud system. Influences of temperature, as well as the concentrations of main salt, reducing agent, hydrogenion and complexing agents on the deposition rate were investigated, respectively. Results The reaction orders of Sn^2＋ , sodium hypophos- phite and H^＋ were 0. 302, 0. 192 and 0.21 ,and those of thiourea, citric acid and tartaric acid were 0. 237, 0. 213 and 0. 081, respectively. The rate constant was 0. 013, the total reaction order was 1. 235, and the apparent activation energy was 11. 184 kJ/mol. Conclusion The kinetic equation of electroless tin plating reaction was established, which provides reference for the technology selection and product control in electroless tin deposition technology.