全Cu_(3)Sn焊点在高温时效下的组织及力学性能  

Microstructure and mechanical property of full Cu 3Sn solder joints during high-temperature aging

作　　者：朱阳阳 李晓延[1] 张伟栋 张虎[1] 何溪 ZHU Yangyang;LI Xiaoyan;ZHANG Weidong;ZHANG Hu;HE Xi(Department of Materials and Manufacturing,Beijing University of Technology,Beijing 100124,China;China Nuclear Industry 23 Construction Co.,Ltd.,Beijing 101300,China)

机构地区：[1]北京工业大学材料与制造学部,北京100124 [2]中国核工业二三建设有限公司,北京101300

出　　处：《材料工程》2022年第9期169-176,共8页Journal of Materials Engineering

基　　金：国家自然科学基金资助项目(51975013)。

摘　　要：对全Cu_(3)Sn焊点进行620℃下不同持续时间的时效处理,研究时效过程中接头微观组织演变,并利用纳米压痕实验及剪切实验表征时效后焊点的力学性能变化。结果表明:在时效过程中,Cu/Cu_(3)Sn界面以平面状析出Cu_(20)Sn_(6)并持续生长,直至Cu_(3)Sn被完全消耗。随后Cu_(20)Sn_(6)向Cu_(20)Sn_(6)和Cu_(13.7)Sn组成的两相层转变,Cu_(13.7)Sn通过消耗两相层在Cu/两相层的界面处以波浪状析出并继续生长,直至占据整个界面区,该过程中伴随着焊缝中间位置孔洞数量和尺寸的生长,最终聚合成微裂纹。Cu_(20)Sn_(6),Cu_(3)Sn,Cu_(13.7)Sn相的硬度分别为9.62,7.15,4.67 GPa,弹性模量分别为146.5,134.0,133.2 GPa。随时效时间的增加,焊点的抗剪强度呈先增大后减小的趋势,在120 min内保持大于20.1 MPa;其断口形貌和断裂路径也随之发生变化。620℃thermal aging was carried out on full Cu_(3)Sn solder joints for various duration,the microstructure evolution of solder joints were investigated.The mechanical properties of solder joints after aging were characterized by nano indentation test and shear test.The results show that,during the thermal aging,the Cu_(20)Sn_(6)is first precipitated in planar along Cu/Cu_(3)Sn interface,it grows continuously until the complete consumption of Cu_(3)Sn.Subsequently,Cu_(20)Sn_(6)transforms to two-phase layer,which consists of Cu_(20)Sn_(6)and Cu_(13.7)Sn.As the aging time increases,Cu_(13.7)Sn is precipitated in waves at the Cu/two-phase layer interface by consuming the two-phase layer and grows continuously until it occupies the entire interface area.Meanwhile,there is growth in the number and size of voids in the middle of the solder joint,which eventually coalesces into microcracks.The hardness of Cu_(20)Sn_(6),Cu_(3)Sn and Cu_(13.7)Sn phases are 9.62,7.15,4.67 GPa,and the elasticity modulus are 146.5,134.0,133.2 GPa,respectively.With the increase of aging time,the shear strength of solder joints increases first and then decreases,and remains more than 20.1 MPa within 120 min.The fracture morphology and fracture path also change.

关 键 词：全Cu_(3)Sn焊点 高温时效 瞬时液相扩散焊 微观组织 抗剪强度 

分 类 号：TN406[电子电信—微电子学与固体电子学]