无VOC免清洗助焊剂的研制及性能测试

Preparation and Study of A VOC-free,No-clean Soldering Flux

针对现有的免清洗助焊剂中对环境和人类健康有害的挥发性有机化合物VOC，研制出一种以水作溶剂不含VOC的水基免清洗助焊剂，使用Sn-3．8Ag-0．7Cu无铅钎料，对该助焊剂进行了性能检测．结果表明，无VOC免清洗助焊剂在外观、稳定性、卤化物含量等方面都符合标准，助焊性能较好，扩展率达到80．1％．焊后残留物少，无腐蚀性．在表面绝缘电阻测试中，使用该免清洗助焊剂通过波峰焊接后的梳形试验板在湿热箱中（85℃，RH85％）放置24、96和168h后，在室温下分别测量梳形试验板的表面绝缘电阻，其最小值为3．8×10^8Ω，达到了免清洗技术的可靠性要求．

The no-clean soldering fluxes used presently contained a high concentration of organic solvents which would generally turn into volatile organic compounds （VOC）. VOC are one of main pollutant sources that contaminate air, and the VOC could cause much harm to environment and human health. Consequently, a new type of no-clean flux which was VOC-free and water-based was developed. Many performance tests had been carried out using Sn-3.8Ag-0.7Cu lead-free solder. The results show that the flux has measured up to the industry standards. The appearance, stability, viscosity and content of halide are up to the standard. The flux works well with Sn-3.8Ag-0.7Cu lead-free solder and the rate of spread is 80.1%. It has little residues after soldering and the residues have no corrosion. The surface insulation resistance （SIR） test was carried out at the condition of ambient temperature 85℃, relative humidity 85 % in the moist-heat chamber. After wave soldering with this new no-clean flux, and the testing panels of comb type circuits laid in the chamber for 24 hours, 96 hours and 168 hours respectively, SIR values were measured at the room temperature. The mini- mum value of testing panels was 3.8 × 10^11Ω. This new no-clean flux has fulfilled the reliability requirements of the standards of no-clean soldering flux.