电子无铅软钎料的超电势研究

Study on Overpotential of the Electronic Solders

主要研究了Sn -Ag系合金钎料的超电势 ,并且与传统的Sn- 40Pb合金进行了对比 ,提出了无铅软钎料研究与开发中应当考虑因超电势变化而引起的问题。在酸、碱两种不同的溶液环境中 ,无铅软钎料和Sn- 40Pb合金的超电势有一定的差异 ,含Bi的Sn-Ag系合金的超电势较低 ,但微量的轻稀土的加入可显著地提高钎料的超电势 ;而在碱性溶液中 ,Sn -Ag系合金的超电势较高 ,但阳极极化、钝化时 ,临界电流和临界电位均低于Sn-

The research on the overpotential properties of Sn-Ag system electronic solders and compared with that of the traditional Sn-40Pb solders. Some advice on the effect of the solder overpotential on the research and the development of the lead-free solders were given. The overpotential varied to some extent in different acidic and alkali solutions. The overpotential of the Bi contained Sn-Ag system solder alloys was lower than that of the Sn-40Pb solders. But it can be improved by the addition of some trace light rare earth. The overpotential of the Sn-Ag system solders was higer, but they have much lower critial current and voltage when the anodes are polarized and passivated in alkali solutions.