药芯焊锡丝飞溅性能的改进和预测

Improvement and Prediction of Spattering Properties of Flux-Cored Solder Wire

设计一种测量助焊剂高温下分解压力的装置,模拟药芯焊锡丝中助焊剂在焊接温度下封闭环境中所产生的变化,探究了加入不同松香和有机酸对助焊剂高温下分解产生压力的影响,采用扩展率实验,对以不同松香作为载体助焊剂的活性和焊后残留进行研究。结果表明含有改性松香的助焊剂分解产生压力比普通松香小,其中氢化松香甘油酯的加入对助焊剂分解压力减小最有利,最终压力为16 k Pa。实验中比较的三种有机酸活性剂,含有高沸点辛二酸的助焊剂分解压力最低为17 k Pa,扩展率实验显示改性松香残留较少,扩展率与无色氢化松香相近。文中设计了三种分解蒸汽压值不同的助焊剂,并灌芯拉丝制成锡丝后进行飞溅率测试,结果表明分解蒸汽压值较低,所制锡丝的飞溅率也较低,消泡剂的加入对减少助焊剂的飞溅率有显著作用,三款助焊剂的分解蒸汽压值最高分别为34、27和26 k Pa,锡丝的飞溅率分别为0.67%,0.32%,0.30%。

A new apparatus was designed to measure vapor pressure of flux during thermal decomposition. It can simulate flux variation under soldering temperature in an enclosed space, and the effects of rosins and organic acids on flux vapor pressure were investigated. Spreading test was applied to study soldering activityand flux residues when using different rosins. The results show that the modified rosin can result in lower fluxvapor pressure than that of normal rosins, and the hydrogenated rosin glycerin ester is the most effective one with final pressure of 16 kPa. For fluxes cosisting of three different organic acids, the formulation with subericacid (high boiling point) exhibits the lowest vapor pressure of 17 kPa. Spreading test demonstrates that fluxes with esterified rosin have less residues and same soldering activity as those of hydrogenated rosin. Three fluxes with different vapor pressure were prepared and filled into solder wire for spattering rate tests. The result suggests that the spattering rate decreases when the flux vapor pressure becomes lower, and deforming agents have strong effects on reducing spattering rate. The vapor pressure of the three fluxes is 34, 27 and 26 kPa respectively, and the coresponding spattering rates are 0.67%,0.32% and 0.30%, respectively.