不同表面活性剂对MSA体系锡电沉积及镀层性能的影响

Effects of different surfactants on electrodeposition of tin in MSA-based electrolyte and properties of tin

在由120 g/L甲基磺酸(MSA)和10 g/L Sn^(2+)组成的镀液中分别添加1 g/L的非离子型表面活性剂(BNO、骨胶或田菁胶)和阴离子型表面活性剂[NES、聚丙烯酰胺(PAM)或十二烷基苯磺酸钠(SDBS)],通过循环伏安分析、接触角测量、霍尔槽试验、X射线衍射(XRD)、扫描电镜(SEM)观察和可焊性测试研究了上述6种表面活性剂对MSA体系中锡电沉积行为及镀层相结构、表面形貌和可焊性的影响。结果表明,这6种表面活性剂均能显著提高镀液的电流效率、沉积速率和对阴极铜基板的润湿性;除PAM外,其他表面活性剂均对氢气的析出有强抑制作用。添加阴离子型表面活性剂NES时镀液的覆盖能力、电流效率和沉积速率最高,电镀所得的镀层平整、细致,主要晶面为(211)、(112)和(321),可焊性最好。

1 g/L of different non-ionic surfactants i.e.BNO,bone glue,and sesbania gum and anionic surfactants i.e.NES,polyacrylamide(PAM),and sodium dodecylbenzenesulfonate(SDBS)were added individually to an electrolyte composed of 120 g/L methanesulfonic acid(MSA)and 10 g/L Sn^(2+)for electrodeposition of tin.The effects of the six kinds of surfactants on the electrodeposition behavior of tin in the MSA electrolyte,and the phase structure,surface morphology,and weldability of the tin coating obtained therefrom were studied by cyclic voltammetry,contact angle measurement,Hull cell testing,X-ray diffraction(XRD),scanning electron microscopy(SEM),and weldability testing.The results showed that all of the six surfactants can greatly improve the cathodic current efficiency and wettability of the electrolyte to copper substrate and the deposition rate of tin coating.Except for PAM,the said surfactants can inhibit the hydrogen evolution effectively.The electrolyte containing the anionic surfactant NES exhibited the best throwing power,the highest current efficiency,and the fastest deposition rate.The tin coating electroplated from it was smooth,fine-grained,and compact with the characteristic X-ray diffraction peaks of crystal planes(211),(112),and(321),and featured the best weldability.