时效对Sn-3.8Ag-0.7Cu／Cu焊料接头的组织和拉伸性能的影响  

EFFECT OF AGING ON MICROSTRUCTURE AND TENSILE PROPERTIES OF Sn-3.8Ag-0.7Cu/Cu SOLDER JOINT

作　　者：李晓延[1] 杨晓华[2] 兑卫真[2] 吴本生[2] 严永长[1] 

机构地区：[1]北京工业大学材料学院,北京100022 [2]福州大学测试中心,福州350002

出　　处：《机械强度》2008年第1期24-28,共5页Journal of Mechanical Strength

基　　金：国家自然科学基金(50475043);北京市自然科学基金(2052006,2082003);教育部博士点基金(20040005012)资助项目~~

摘　　要：研究Sn-3.8Ag-0.7Cu/Cu焊料接头界面的微观组织在150℃时效不同时间后的演变过程,对时效不同时间的试样进行抗拉强度测定,并在扫描电镜下进行动态拉伸原位观察和拉伸断口的形貌观察。结果表明,Sn-3.8Ag-0.7Cu/Cu焊料接头试样在焊后的界面上形成扇贝状的Cu6Sn5金属间化合物(intermetallic compound,IMC)层,随着时效时间的增加,界面IMC的厚度增加,Cu6Sn5扇柱变长变粗,最后离开界面层进入焊料,时效480 h后在焊料和Cu6Sn5界面析出Ag3Sn相。拉伸实验结果表明,焊料接头的强度在时效初期略有增加,时效48 h后强度逐渐下降;动态拉伸结果表明,时效初期断裂发生在焊料基体内部,随着时效时间的增加,断裂发生的位置逐渐向界面转移,在时效480 h后断裂完全发生在界面化合物层。The microstructure evolution of the interface of Sn-3.8Ag-0.7Cu/Cu solder joint after aging for different time at 150℃ was investigated. The tensile strength test was carried out on the samples after aging for different time and dynamic tensile in situ observation and tensile fracture surface of the samples were studied by SEM （scanning electron microscopy）. The results show that scallop-like Cu6Sn5 IMC （intermetallic compound） layer formed at the interface of Sn-3.8Ag-0.7Cu/Cu joint as soldered. With the increase of aging time, the depth of interfacial IMC increased and Cu6Sn5 column became lengthened and coarsened and finally left interfacial IMC layer into solder. The Ag3Sn phase formed at the interface of solder and Cu6Sn5 after aging for 480 h. The results of tensile experiment show that the tensile strength of the joint slightly increases at the initial stages of aging and decreases gradually after aging for 48 h. The results of dynamic tensile show that fracture took place inside the solder matrix at the initial stages of aging. With the increase of aging time, the position of fracture gradually moves to interface and after aging for 480 h, the fracture completely took place at the interfacial IMC layer.

关 键 词：无铅焊料 金属间化合物(intermetallic compound IMC) 时效拉伸断裂 

分 类 号：TG407[金属学及工艺—焊接] O346.23[理学—固体力学]