Cu基底表面氧化对倒装焊的影响  

Influence of Cu substrate surface oxidation on flip chip reflow

作　　者：宿磊 沈俊杰 廖广兰[2] 史铁林[2] Su Lei1, Shen Junjie2 ,Liao Guanglan2 ,Shi Tielin2(1 School of Mechanical Engineering, Jiangnan University, Wuxi 214122, Jiangsu China; 2 School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, Chin)

机构地区：[1]江南大学机械工程学院,江苏无锡214122 [2]华中科技大学机械科学与工程学院,湖北武汉430074

出　　处：《华中科技大学学报（自然科学版）》2018年第3期80-84,共5页Journal of Huazhong University of Science and Technology(Natural Science Edition)

基　　金：国家自然科学基金资助项目(51675210,51675209,51705203);江苏省自然科学基金资助项目(BK20160183);国家重点基础研究发展计划资助项目(2015CB057205);中国博士后科学基金资助项目(2017M611690)

摘　　要：研究了基底Cu焊盘表面发生氧化对倒装芯片回流焊的影响,分别采用未发生氧化的Cu基底和在200℃空气中加热5 h后引入氧化层的基底样片进行试验,对回流焊接试验后的样片截面形貌进行扫描电子显微镜测试,分析测试结果发现：当温度高于228℃时正常Cu基底上的焊球熔化后沿焊盘延伸并溢出焊盘表面,而引入氧化层基底上的焊球没有溢出焊盘表面.研究表明：焊料在Cu氧化基底上的延伸速率低于其在正常Cu基底上的延伸速率,进一步说明焊料在Cu氧化基底上的表面张力比正常Cu基底大,可以承受更大的外力作用.The influence of Cu substrate surface oxidation on flip chip reflow was studied.Two types of copper substrates,without oxidation,with oxide layer induced by heating in 200 ℃ for 5 h in ambient condition,were investigated.After reflow,the morphologies of sections of flip chip samples were observed by SEM（scanning electron microscope）.It can be found that melting solder balls moves forward along surfaces of Cu pads and over it.While melting solder balls moves forward along oxides layer,and it stops at edge of pads.Moving speed of melting solder balls in oxides layer is much lower than in surface of Cu pads.The surface tension of SAC solder on cuprous oxide layer is bigger than that on surface of normal Cu pads,which means it can hold larger additional force.

关 键 词：倒装焊器件 浸润性 Cu表面氧化 焊料 形貌 

分 类 号：TP305.94[自动化与计算机技术—计算机系统结构]