The components including activator, film-forming agent, and surfactant used in environmentally friendly no-clean soldering flux were selected experimentally. The optimum proportion of benzotriazole (BTA), a common corrosion inhibitor, was determined by AC impedance method. The influence of individual component in the flux system on its corrosion inhibition was discussed. The results indicated that the corrosiveness of flux was decreased as a result of the combination of acid with amine, and the corrosion inhibition of the flux system was remarkably improved by using BTA as corrosion inhibitor. The prepared flux system has the optimum corrosion inhibition and a film resistance of 6.2 × 105 Ω·cm2 when: malic acid and adipic acid in a ratio of 1∶5 (by mol) is combined with triethanolamine; the molar ratio of mixed acid to triethanolamine is equal to 11∶1; and mass fraction is 3.15% for acid-amine mixed solution, 0.2% for polyethylene glycol 2000 as surfactant, 0.05% for corrosion inhibitor BTA, 1.5% for both isopropyl alcohol and ethylene glycol monobutyl ether as co-solvents, and 0.2% for polyvinyl alcohol as film-forming agent. The flux system has weak corrosion to the metallic copperplate substrate.%通过实验优选了环保型水性免清洗助焊剂所用的活化剂、成膜剂和表面活性剂等组分.采用交流阻抗法确定了缓蚀剂苯并三氮唑(BTA)的最佳配比,探究了体系中各组分对助焊剂缓蚀性能的影响.结果表明,酸-胺复配可以降低助焊剂的腐蚀性,而缓蚀剂BTA能显著提高助焊剂体系的缓蚀性能.当苹果酸和己二酸以1∶5的物质的量之比与三乙醇胺复配,n复配酸∶n三乙酵胺=11∶1,且酸-胺复合液的质量分数为3.15％、表面活性剂聚乙二醇2000的质量分数为0.2％、缓蚀剂BTA的质量分数为0.05％,助溶剂异丙醇和乙二醇丁醚的质量分数均为1.5％,成膜剂聚乙烯醇的质量分数为0.2％时,所制备的助焊剂体系的缓蚀性能最佳,膜电阻最大,为6.2×105 Ω·cm2.该助焊剂体系对基底金属铜板的腐蚀性较弱.
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