大气污染物硫酸铵和氯化钠混合盐粒沉降对电路板铜大气腐蚀的加速机制  

Influence of Co-deposition of Pollutant Particulates Ammonium Sulfate and Sodium Chloride on Atmospheric Corrosion of Copper of Printed Circuit Board

作　　者：马小泽 孟令东 曹祥康 肖松 董泽华[1] MA Xiaoze;MENG Lingdong;CAO Xiangkang;XIAO Song;DONG Zehua(School of Chemistry and Chemical Engineering,Huazhong University of Science and Technology,Wuhan 430074,China;School of Materials,Academy of Armored Forces,Bejing 100086,China)

机构地区：[1]华中科技大学化学与化工学院,武汉430074 [2]装甲兵学院材料学院,北京100086

出　　处：《中国腐蚀与防护学报》2022年第4期540-550,共11页Journal of Chinese Society For Corrosion and Protection

基　　金：国家自然科学基金(51371087)。

摘　　要：采用电化学阻抗 (EIS)、石英晶体微天平 (QCM) 和铜箔电阻探针 (TER) 等多种大气腐蚀测量技术,以表面沉积不同比例 (NH_(4))_(2)SO_(4)和NaCl混合盐粒下的电路板铜箔为样本,在气候试验箱中模拟研究了电路板铜在模拟污染大气环境下的初期大气腐蚀行为。结果表明:在30 ℃ RH90%环境中且表面沉积量相同时,在腐蚀初期 (<30 h),(NH_(4))_(2)SO_(4)和NaCl混合盐粒对铜的腐蚀性比沉积单一NaCl盐粒的体系更强;但30 h后,情况发生反转,混合盐粒对铜的腐蚀相比单一 NaCl 盐粒体系反而显著降低,且当混合比例为 1∶1 时,(NH_(4))_(2)SO_(4)对NaCl 腐蚀的抑制作用最强 (抑制比达 84%)。通过腐蚀产物的 SEM、XRD、XPS 分析可知,在腐蚀前期,由于NH_(4)^(+)对Cu的腐蚀促进作用使铜表面快速形成了较为致密的Cu_(2)O 腐蚀产物,从而显著减缓了铜基底腐蚀。尽管沉积NaCl盐粒的铜表面也生成了Cu_(2)O腐蚀产物,但相对比较疏松多孔,反而会因为腐蚀产物的阴极促进作用加速腐蚀产物层下的Cu腐蚀。The initial atmospheric corrosion behavior of Cu foils induced by co-depositioned with of particulates with different proportions of (NH_(4))_(2)SO_(4)and NaCl particles in a weathering chamber was assessed via electrochemical impedance (EIS), quartz crystal microbalance (QCM) and thin foil electrical resistance probe (TER). The results show that the mixed salt particles of (NH_(4))_(2)SO_(4)and NaCl promote the initial atmospheric corrosion of PCB-Cu compared with sole NaCl salt particles in the initial 30 h when the total deposition amount is equal. However, after 30 h, the atmospheric corrosion rate of PCB-Cu beneath the mixed salts is significantly lower than that beneath the sole NaCl particles when the mixing ratio of(NH_(4))_(2)SO_(4)to NaCl is 1: 1, and the inhibition ratio of Cu corrosion can reach 84%, indicating that the(NH_(4))_(2)SO_(4)can refrain the corrosion of PCB-Cu beneath induced by NaCl particles. According to the SEM,XRD and XPS analysis of corrosion products, in the early stage of corrosion, due to the catalytic effect of NH4^(+) on the corrosion of Cu, dense Cu_(2)O corrosion products quickly formed on the copper surface, which dramatically refrains the corrosion of Cu substrate. Although Cu_(2)O corrosion products are also generated on PCB-Cu surface where NaCl particles are deposited, they are relatively loose and porous, which could accelerate the corrosion of Cu beneath porous Cu_(2)O layer due to the cathodic depolarization of the corrosion product layer.

关 键 词：大气腐蚀 电路板铜 污染物 腐蚀监测 电阻探针 石英晶体微天平 

分 类 号：TG174[金属学及工艺—金属表面处理]