添加微量Zn对Sn-58Bi/Cu焊点老化过程中界面演变以及力学性能的影响  

Effect of Trace Zn Addition on Interfacial Evolution and Mechanical Properties of Sn-58Bi/Cu Solder Joints during Aging

作　　者：王凤江[1] 何其航 WANG Fengjiang;HE Qihang(Materials Science and Engineering,Jiangsu University of Science and Technology,Zhenjiang 212000)

机构地区：[1]江苏科技大学材料科学与工程学院,镇江212000

出　　处：《机械工程学报》2022年第2期284-290,共7页Journal of Mechanical Engineering

基　　金：国家自然科学基金资助项目(51875269)。

摘　　要：通过向Sn-58Bi焊料中加入微量Zn元素,研究了Sn-58Bi-xZn(x=0,0.2,0.5,1.0)焊点在老化过程中界面金属间化合物(Intermetallic compounds,IMCs)的生长行为以及对力学性能的影响。研究发现,加入微量Zn后,界面IMCs由Cu_(6)Sn_(5)转变为Cu_(6)(Sn,Zn)_(5)。当Zn的添加量达到1.0wt%时界面IMCs为Cu_(5)Zn_(8)。添加Zn显著抑制了界面Cu_(3)Sn在老化过程中的生长。Sn-58Bi-0.5Zn/Cu焊点界面处IMCs在老化过程中出现分层现象,形成Cu_(6)(Sn,Zn)_(5)/Cu_(5)Zn_(8)/Cu_(6)(Sn,Zn)_(5)结构。添加微量的Zn会降低Sn-58Bi/Cu的剪切力,但是随着老化时间的增加,Sn-58Bi-xZn/Cu焊点的剪切力高于Sn-58Bi/Cu焊点,焊点的断裂均由韧性断裂逐渐向韧脆混合断裂模式转变。微量Zn的添加有助于提高焊点的长期可靠性。The effect of trace Zn addition on the growth of interfacial IMCs and the mechanical properties of Sn-58Bi solder joints under thermal aging were investigated.The results indicated that with minor Zn addition,the interfacial IMCs changed from Cu_(6)Sn_(5) to Cu_(6)(Sn,Zn)_(5).When the Zn content increased to 1.0 wt%,Cu_(5)Zn_(8) phases were formed at the interface between Sn-58Bi-1.0Zn/Cu.The addition of Zn suppressed the growth of Cu_(3)Sn IMCs during thermal aging.The sandwich structure of Cu_(6)(Sn,Zn)_(5)/Cu_(5)Zn_(8)/Cu_(6)(Sn,Zn)_(5)IMCs was formed at the Sn-58Bi-0.5Zn/Cu interface after aging for 20 days.The shearing force of the solder joints decreased with the addition of Zn.However,the shearing force of Sn-58Bi-xZn solder joints were higher than that of the Sn-58Bi joints after a long time aging.The fracture mode of the solder joints changed from the ductile fracture to the mixed ductile-brittle fracture.It indicated that the long-time reliability of the solder joints was benefited from Zn addition.

关 键 词：Sn-Bi焊料 界面化合物 老化 可靠性 力学性能 

分 类 号：TG425[金属学及工艺—焊接]