氮气保护对Sn-Cu-Ni-Ce无铅钎料润湿性的影响

Effects of N_2 protection on wettability of Sn-Cu-Ni-Ce lead-free solder

基于润湿平衡原理测定了不同温度与不同气氛下Sn-Cu-Ni-Ce钎料在Cu基板上的润湿行为，研究了气氛、温度以及微量稀土元素Ce对其润湿性能的影响。结果表明。采用氮气保护时，Cu基板表面张力提高，钎料表面张力降低，润湿时间缩短了20％～50％，润湿力也显著提高；温度升高使Sn-Cu-Ni-Ce钎料的表面张力减小，显著缩短了钎料在Cu基板上的润湿时间；稀土元素Ce可显著降低熔融钎料的表面张力和钎料，基板间的界面张力，从而使Sn-Cu-Ni-Ce钎料的润湿性能较Sn-Cu-Ni钎料有了显著的改善。

The wettability of Sn-Cu-Ni-Ce solder on Cu substrate was investigated by wetting balance testing method under the conditions of different temperatures and atmospheres,and the effects of atmosphere,temperature and small amount of rare-earth element Ce added to the solder on the wettability of Sn-Cu-Ni solder were also studied respectively.The results indicate that wetting time of the lead-free solder is reduced by 20%-50%,and the wetting force is also increased in N_2 atmosphere because of the surface tension increase of the Cu substrate and the surface tension decrease of the Sn-Cu-Ni-Ce solder.With temperature increasing,the surface tension of the Sn-Cu-Ni-Ce solder decreases,so wetting time is observably reduced.rare-earth element Ce could lead to decrease evidently the surface tension of the Sn-Cu-Ni solder as well as the interfacial tension between solder and Cu substrate,so the wettability of Sn-Cu-Ni-Ce solder is better than that of Sn-Cu-Ni solder.