Chen Huimin, Wang Shuaixing, Liao Zhixiang, Peng Shusen, Du Nan
School of Materials Science and Engineering, Nanchang Hangkong University Nanchang 330063 P. R. China
National Defense Key Discipline Laboratory of Light Alloy Processing Science and Technology, Nanchang Hangkong University Nanchang 330063 P. R. China.
RSC Adv. 2022 Oct 25;12(46):29697-29708. doi: 10.1039/d2ra05411f. eCollection 2022 Oct 17.
Benzotriazole (BTAH) and 2-mercaptobenzothiazole (MBT) are mixed to passivate electroplated copper coatings. The growth process of passive films is comprehensively analyzed from the surface potential, microstructure and chemical composition by potential-time curve, FESEM and XPS. Meanwhile, the corrosion resistance of copper coatings with different passivation treatments is evaluated by potentiodynamic polarization curves and electrochemical impedance spectroscopy. During the composite passivation process of BTAH and MBT, the copper coating undergoes the following steps: chemical dissolution of the copper coating, preferential adsorption of MBT, formation of Cu(i)-BTA complex film and CuO, and synergistic growth of Cu(i)-BTA and Cu(i)-MBT. A protective film with a thickness of about 233 nm, containing the inner layer of BTA-Cu(i) and MBT-Cu(i) and the outer layer of MBT-Cu(i) and CuO, is formed on the copper coating after composite passivation. The composite passivation film significantly improves the corrosion resistance of copper coatings, and its corrosion inhibition efficiency for copper coatings reaches 90.7%, which is far better than that produced by using BTAH or MBT alone.
苯并三唑（BTAH）和2-巯基苯并噻唑（MBT）混合用于钝化电镀铜涂层。通过电位-时间曲线、场发射扫描电子显微镜（FESEM）和X射线光电子能谱（XPS）从表面电位、微观结构和化学成分等方面综合分析钝化膜的生长过程。同时，通过动电位极化曲线和电化学阻抗谱评估不同钝化处理的铜涂层的耐蚀性。在BTAH和MBT的复合钝化过程中，铜涂层经历以下步骤：铜涂层的化学溶解、MBT的优先吸附、Cu（Ⅰ）-BTA络合物膜和CuO的形成以及Cu（Ⅰ）-BTA和Cu（Ⅰ）-MBT的协同生长。复合钝化后，在铜涂层上形成了一层厚度约为233nm的保护膜，其内层为BTA-Cu（Ⅰ）和MBT-Cu（Ⅰ），外层为MBT-Cu（Ⅰ）和CuO。复合钝化膜显著提高了铜涂层的耐蚀性，其对铜涂层的缓蚀效率达到90.7%，远优于单独使用BTAH或MBT所产生的效果。
