原位置换法稳定导电胶接触电阻的研究  

Study on stabilizing contact resistance of electrically conductive adhesives by in-situ replacement method

作　　者：高宏[1] 刘岚[1] 卢嘉圣[1] 罗远芳[1] 贾德民[1] 刘孔华[1] 

机构地区：[1]华南理工大学材料科学与工程学院,广东广州510640

出　　处：《功能材料》2011年第3期528-532,536,共6页Journal of Functional Materials

基　　金：国家自然科学基金资助项目(50608034;50873036);中央高校基本科研业务费资助项目(2009ZM0306)

摘　　要：研究两种水溶性银盐(硝酸银及乙酸银)对银填充导电胶的热行为和体积电阻率的影响,及湿热老化条件下在锡表面接触电阻的稳定作用。DSC测试结果表明,这两种银盐的引入对导电胶固化行为没有影响。导电胶在湿热老化600h后,添加了2%(质量分数)的硝酸银和1.5%(质量分数)乙酸银样品体积电阻率分别下降了48.5%和47.4%,而空白样仅降低了27.3%。另外当硝酸银添加量≥1%(质量分数)或乙酸银≥0.5%(质量分数)时,经湿热老化后导电胶在锡表面的接触电阻非常稳定。XRD、XPS和SEM结果表明银盐经过湿热老化后在锡面发生原位置换,在导电胶/锡界面形成一层致密的银层,可以消除与导电填料银粉的电位差,阻止了电化学腐蚀从而达到稳定接触电阻的效果。The effects of two kinds of water-soluble silver salt（silver nitrate or silver acetate） on heating behaviors,bulk resistivity of ECAs and contact resistance of ECAs on tin surfaces under aging condition were investigated.The DSC results show the addition of silver salt does not influence curing behaviors of ECAs.The bulk resistivity of ECAs with 2wt% silver nitrate or 1.5wt% silver acetate decrease 48.5% or 47.4% after damp heat aging 600h,respectively,but the control samples only decrease 27.3%.In addition,the contact resistance of ECAs with more than or equal to 1wt% silver nitrate or 0.5wt% silver acetate is stable on tin finish after damp heat age.XRD,XPS and SEM results indicate that under the aging condition,the silver salt has plated on tin surfaces by in-situ replacement reaction,forming a compact silver layer on the interface between ECA/tin,which eliminated the electrochemical potential difference with the silver fillers in ECAs and prevented the occurrence of galvanic corrosion.Thus,the stabilization of the contact resistance of ECAs is obtained.

关 键 词：导电胶 接触电阻 水溶性银盐 原位置换 电化学腐蚀 

分 类 号：TQ437[化学工程] TQ323