温度与镀层对Sn-Cu-Ni无铅钎料润湿性能的影响

Effects of temperature and coatings on wettability of Sn-Cu-Ni lead-free solder

采用润湿平衡法测定了在不同试验温度下Sn-Cu-Ni无铅钎料在Cu,Au/Ni/Cu,SnBi/Cu三种基板上的润湿时间和润湿力,研究了钎焊温度对Sn-Cu-Ni无铅钎料在不同基板上润湿性能的影响。结果表明,温度升高使Sn-Cu-Ni无铅钎料的表面张力减小,能显著缩短钎料在铜片上的润湿时间,提高润湿力;Ni/Au或SnBi等镀层能显著降低钎料/基板界面张力,因此Sn-Cu-Ni无铅钎料在Au/Ni/Cu或SnBi/Cu基板上的润湿性能优于在Cu基板上的润湿性能。

Wetting times and wetting forces of Sn-Cu-Ni lead-free solder for different temperatures and three kinds of substrates, including Cu, Au/Ni/Cu, and SnBi/Cu, were measured by means of wetting balance method. The effects of soldering temperature on wettability of Sn-Cu-Ni lead-free solder on different substrates were also studied. The results indicate that with the increase of temperature, the surface tension of the lead-free solder decreases,and the wetting times are reduced observably, and the wetting forces are increased evidently. The wettability of solder on Au/Ni/Cu or SnBi/Cu substrate is better than that on Cu substrate owing to the decrease of the interfacial tension between solder and substrate by way of plating Ni/Au or SnBi coating.