微合金化对Sn-9Zn基无铅钎料润湿性能的影响

熔炼制备了纯的以及含微量Al、Mg、Ti、Bi、重稀土Y、混合轻稀土RE和一种富P非金属活性组元NM的Sn-9Zn基合金,通过测量这些合金以及商用Sn-37Pb焊料在铜基板上的铺展面积比较了它们对铜的润湿性能。结果表明Al、Ti和 Mg不利于提高合金在铜上的润湿性或附着力;Y的改善作用不大;而Bi、RE和NM则能明显改善Sn-9Zn合金对铜的润湿性。在此基础上进一步研究了RE和NM含量对Sn-9Zn润湿性能的影响。以铺展面积衡量,本研究所达到的最佳改善效果使Sn-9Zn合金对铜的润湿性由Sn-37Pb焊料润湿性水平的45.4%提高到了70.3%。

Effect of Microalloying on Wettability of Sn-9Zn Lead-free Solder

To improve the wettability of Sn-9Zn lead-free solder, an investigation was carried out into the effects of different addictives on the wettability of the alloy to Cu substrate. The addictives are Al, Mg, Ti, Y, Bi, RE (a mixed rare earth), and a non-metallic rich P active constituent. The results show that Al, Ti and Mg have adverse effect on the wettability or adherence of the alloy to Cu. Y has no significant effect, while Bi, RE and the non-metallic element can significantly improve the wettability. The effect of the content of RE and the non-metallic element on the wettability was further investigated. The maximum improvement achieved is that, in terms of spread area on Cu, the wettability increases from 45.4% to 70.3% as compared with the conventional Sn-37Pb solder.