Sn-9Zn-xAl无铅钎料润湿性能

Wettability of lead-free solders of Sn-Zn-xAl

关键词:  无铅钎料  Sn-Zn  Al  润湿性  氮气

Key words:  lead-free solder  Sn-Zn  Al  wettability  nitrogen

摘要:

采用润湿平衡法测试了不同温度下Sn-9Zn-xAl无铅钎料在空气和氮气两种气氛下的润湿性能,研究探索了合金元素Al的添加量、气氛和温度对Sn-9Zn-xAl无铅钎料润湿性能的影响规律。结果表明,添加Al元素以后,Sn-Zn-xAl无铅钎料的润湿性得到明显改善,在使用ZnCl₂-NH₄Cl助焊剂时,Al的最佳添加量为0.02%(质量分数),在使用免清洗助焊剂时,Al的最佳添加量为0.005%(质量分数);采用氮气保护时,Cu基板表面张力提高,钎料的氧化减少、表面张力降低,明显改善了钎料在Cu基板上的润湿性能;在215~245℃时,温度升高使钎料的表面张力减小,提高了钎料的润湿性能。

Abstract:

At different temperatures, the wettability of leadfree solders of Sn-9Zn-xAl was tested by means of wetting balance method in air and N₂ atmospheres.Effects of addition of Al, atmosphere and temperature on the wettability of lead-free solders of Sn-Zn-xAl were studied.The results indicate that with the addition of Al, the wettability of Sn-9Zn lead-free solders is improved obviously.With the ZnCl₂-NH₄Cl flux, the optimal addition of Al is about 0.02wt.%, and with the non-cleaning flux, the optimal addition of Al is about 0.005wt.%.In N₂ atmosphere, the wettability of solder on Cu substrate was extremely improved because the surface tension of the Cu substrate increases and the oxidation of the solders decreases, the surface tension of the solders decreases.With the increase of the temperature, from 215℃ to 245℃, the wettability of the solders is improved due to the decrease of the surface tension of the solders.