锡锌系无铅钎料用免清洗助焊剂的润湿性评价

Wettability evaluation of new soldering fluxes for Sn-Zn lead-free solder

简要介绍了锡锌系无铅钎料的研究背景,针对锡锌系钎料容易氧化和润湿性差的缺点,研制了一种无松香无卤素的新型免清洗助焊剂。并且选用一种无机盐助焊剂和一种松香型助焊剂作为对比,进行了扩展率试验和润湿力试验以评价3种助焊剂的润湿性。试验结果表明,这种新型免清洗助焊剂能够提高Sn-9Zn共晶钎料的润湿性,并且助焊剂残留物少,无腐蚀,可免除焊后清洗工艺,符合环保要求,有利于促进Sn-9Zn无铅钎料在电子工业中的实际应用。

The background and development status of Sn-Zn solder was introduced briefly. Aiming at the drawbacks of Sn-Zn solder such as poor wettability and inferior oxidation resistance, one kind of new no-clean flux without rosin and halide was developed. Two kinds of fluxes, one corrosive flux with inorganic salt and one rosin flux were chosen for contrast test. Spread ratio test and wetting force test were carried out to evaluate the wettability of these three fluxes. The results showed that the new no-clean flux was capable of improving the wetting ability of Sn-gZn eutectic solder, besides, it had little corrosion products on the printed circuit board （PCB）. It accorded with the requirement of environmental protection since the cleaning process after soldering could be exempted. Therefore, the new no-clean flux was propitious to speed the practical application of Sn-gZn solder in electronic industry.