环保型免清洗助焊剂组分对其腐蚀性能的影响及其机理

Effect of main components of environmental-friendly no-clean flux on its corrosivity and its mechanism

主要研究活化剂、表面活性剂和缓蚀剂3种组分对环保型免清洗助焊剂腐蚀性能的影响。采用交流阻抗法研究了各组分对铜电极缓蚀性能的影响;通过扫描电镜观察测试了各组分对梳形试件的腐蚀;借助热分析研究了组分残留及相互作用。结果表明,随活化剂酸性的减弱,助焊剂体系的腐蚀性逐渐减弱;壬基酚聚氧乙烯醚系列的非离子表面活性剂有助于降低体系的腐蚀性能;缓蚀剂苯并三氮唑(BTA)的添加能显著改善助焊剂体系的缓蚀性能。用壬基酚聚氧乙烯(50)醚(w=0.2%)作表面活性剂、丁二酸和苹果酸复配(w=1.6%)作活化剂,BTA作缓蚀剂(w=0.06%)制备的助焊剂体系的膜电阻最大,在湿热条件下助焊剂对梳形试件的腐蚀明显降低,缓蚀性能最佳。热分析结果表明,体系缓蚀性能的改善可能是有机酸与丙三醇发生的酯化反应所致。

The influence of three main components of environmental-friendly no-clean flux（activator,surfactant and inhibitor）on its corrosivity was studied.The effect of different components on the copper electrode inhibition performance was studied by using alternating current（AC）impedance.The surface corrosion of three main components on comb patterns was also observed with scanning electron microscope,and the residue of flux and interaction were tested by thermal analysis.The results showed that the structure and acidity of the activator had some effect on the corrosivity of the flux.The weaker the acid,the weaker the corrosivity of the flux.The corrosion inhibition of the flux could be improved by the addition of polyoxyethylene nonyl phenyl ether as nonionic surfactant.With benzotriazole（BTA）as inhibitor,the corrosion inhibition performance of the flux was promoted effectively.The results showed that the no-clean flux,using polyoxyethylene nonyl phenyl ether（50）（w=0.2%）as surfactant,showed lower surface tension and better wetting properties.The mixture of succinate and malic acid（w=1.6%）as activator could help to increase the activity of flux.The welding plate expressed less corrosivity after soldering.The flux using BTA as corrosion inhibitor（w=0.06%） showed optimum corrosion inhibition performance,with high membrane resistance and lower inhibition on hydrothermal condition.The mechanisms of this action were discussed by thermal analysis,which showed that the esterification reaction between organic acid and glycerol may play an important role for corrosion inhibition performance improvement in the welding process.