Sn-9Zn无铅电子钎料助焊剂研究

Sn-9Zn共晶合金在一般松香助焊剂条件下润湿性较差。开发了一种新的改性松香助焊剂。用铺展面积测量和润湿天平两种手段,表征不同助焊剂条件下Sn-9Zn合金对铜的润湿性,用失重测量表征助焊剂对铜和焊料合金的腐蚀性。结果表明:在乙醇–松香中加入少量SnCl2作为助焊剂可大大改善Sn-9Zn对铜的润湿性,但对焊料合金有一定的腐蚀性。选择了一种具有较强活性的有机碱性缓蚀剂,含SnCl2的助焊剂中加入该缓蚀剂后可基本消除腐蚀作用,同时还改善了润湿性。

Development of Fluxes for Sn-9Zn Lead-free Electronic Solder

Sn-9Zn eutectic alloy wettability is poor when used with conventional rosin flux. A new fluxes for Sn-9Zn by modifying rosin based fluxes were developed. Spreading ratio measurement and wet balance was used to characterize the wettability under various fluxes. Weight loss measurement was adopted to examine the corrosiveness of the fluxes. The results show that the wettability Sn-9Zn to copper can be greatly improved by minor addition of SnCl2 to ethanal-rosin as a flux. However, the SnCl2-containing flux is found corrosive to the solder alloys. A inhibitor with high activity was chosen. Addition of this inhibitor to the SnCl2-containing flux can diminish its most corrosiveness, while further enhancing the wettability of Sn-9Zn alloy to copper.