松香含量对Zn20Sn钎料用松香基助焊剂的影响

Effect of rosin content on rosin-based fluxes for Zn20Sn solders

锌基钎料润湿性差已经成为锌基钎料推广应用的瓶颈.通过在传统松香中加入适量有机酸活性剂、溶剂、缓蚀剂及表面活性剂等化合物组成Zn20Sn钎料用新型松香基助焊剂,来改善Zn20Sn钎料在铜基板上的润湿性能.结果表明,松香含量在40%-60%范围内时,助焊剂在物理稳定性、不粘性、腐蚀性等方面均符合国家标准要求;Zn20Sn钎料在铜基板上的铺展面积和铺展率随着松香含量的增加呈先增后减的趋势.当松香含量为55%时,Zn20Sn钎料在铜基板上的铺展性最好,铺展面积和铺展率达到最大,分别为70.3 mm2和87%,焊点饱满光亮,焊缝无明显缺陷,显示其对Zn20Sn钎料具有良好的助焊效果.

The poor wetting of zinc-based alloys has become the bottleneck restraining their extensive applications.In this paper,a new flux was produced by adding proper amounts of organic acid,solvent,corrosion inhibitor,and surface active agent to improve the wetting properties of Zn20Sn solder.The results showed that when the rosin content was within the range of 40%-60%,the physical stability,inadhesion and corrosion properties of the flux could meet the requirements of relevant national standards.With the increasing of the rosin content,the spreading area and spreading ratio of the Zn20Sn solder increased first and then decreased.When the rosin content was about 55%,the spreading area and spreading ratio of the Zn20Sn solder reached the maximum values as 70.3 mm2 and 87%,respectively.And no apparent defects occurred in the resultant joint,indicating that the flux benefited to enhance the soldering effects of Zn20Sn solder.