热时效下铜核异质焊点界面反应及其对力学性能的影响  

Interfacial reaction at Cu-core heterogenous solder joints and its effects on mechanical properties during isothermal aging

作　　者：姚宗湘 刘义凯 周杨 王刚 尹立孟 李红菊 蔡娇 YAO Zongxiang;LIU Yikai;ZHOU Yang;WANG Gang;YIN Limeng;LI Hongju;CAI Jiao(School of Mechanical Engineering and Intelligent Manufacturing,Chongqing University of Science and Technology,Chongqing,401331,China;Key Laboratory of Jiangxi Province for Aeronautical Component Forming and Connection,Nanchang,330063,China;School of Metallurgy and Power Engineering,Chongqing University of Science and Technology,Chongqing,401331,China;Office of Scientific Research,Chongqing University of Science and Technology,Chongqing,401331,China)

机构地区：[1]重庆科技大学,机械与智能制造学院,重庆401331 [2]江西省航空构件成形与连接重点实验室,南昌330063 [3]重庆科技大学,冶金与动力工程学院,重庆401331 [4]重庆科技大学,科研处,重庆401331

出　　处：《焊接学报》2025年第3期51-58,共8页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(52175288);重庆市自然科学基金面上项目(CSTB_(2)022NSCQ-MSX1577,CSTB_(2)022NSCQ-MSX1236);江西省航空构件成形与连接重点实验室开放课题(HKGJ-2001)。

摘　　要：研究了Ni/Cu铜核+Solder/Cu异质铜核焊点(Ni-Cu铜核焊点)在100℃时效0、48、120和360 h下界面金属间化合物(intermetallic compound,IMC)的生长与演化行为,以及热时效作用下焊点的拉伸性能与断裂行为.结果表明,在Ni-Cu铜核焊点中,在Ni基/Solder、Solder/Cu铜核以及Cu铜核/Solder界面处均形成(Cu,Ni)_(6)Sn_(5) IMC层,表明Cu原子穿过钎料到达Ni基侧参与界面反应,Solder/Cu基界面处形成Cu_(6)Sn_(5) IMC层,4个界面的IMC层均平整连续,且主要呈锯齿状.界面IMC层厚度均随着热时效时间的延长而逐渐增大,其生长行为以扩散控制为主.在相同时效条件下,近Cu基侧的两个界面IMC层厚度分别大于近Ni基侧的IMC层的厚度,Ni-Cu铜核焊点的拉伸强度略高于Cu/Cu铜核+Solder/Cu(Cu-Cu铜核焊点)焊点的,两种焊点的拉伸强度均随热时效时间延长而降低,且断裂模式均以韧脆混合断裂为主,其断裂位置主要发生在近Cu基侧IMC层厚度较大的体钎料处,随着热时效时间的延长,断裂位置越倾向于近Cu基侧IMC层处,采用Ni替代Cu作基体,可减缓界面层的生长速度,有利于提高铜核焊点的可靠性.创新点:(1)分析了Ni/Cu铜核+Solder/Cu铜核焊点在热时效条件下的原子迁移及界面反应.(2)研究了热时效时间对Ni/Cu铜核+Solder/Cu铜核异质焊点微观组织和力学性能的影响.(3)阐明了热时效作用下Ni/Cu铜核+Solder/Cu铜核异质焊点的断裂机制.Ni/Cu-core+Solder/Cu heterogenous Cu-core solder joints(Ni-Cu Cu-core joints)were subjected to aging experiments at 100℃for 0 h,48 h,120 h,and 360 h,respectively.The microstructure evolution of interfacial intermetallic compound(IMC),tensile properties and fracture behavior of Ni-Cu Cu-core joints were investigated.The results show that,at as-reflowed joints,the ternary(Cu,Ni)_(6)Sn_(5) phases are formed at the Ni/Solder and Solder/Cu-core interface and the Cu_(6)Sn_(5) phases are formed at the Solder/Cu interface in Ni-Cu Cu-core joints.Interfacial reaction occurs at Solder/Ni interfaces in Ni-Cu Cu-core joints by Cu atoms diffusing to the Ni base through solder.The IMC layers are flat,continuous,and mainly serrated at all interfaces.During the isothermal aging,the thicknesses of the IMC layers monotonically increase with increasing aging time and the interface growth behavior is mainly controlled by diffusion.At the same aging conditions,the thicknesses of the IMC layers on the near Cu base side are greater than that on the near Ni base side,respectively.The tensile strength of Ni-Cu joints is slightly higher than that of Cu/Cu-core+Solder/Cu(Cu-Cu)joints.The tensile strength of Ni-Cu and Cu-Cu solder joints decreases with aging time prolonged,and the fracture mode is mainly ductile brittle mixed fracture.The fracture location mainly occurs at the bulk solder with larger thickness of IMC layer near the Cu base side.With the increase of the aging time,the fracture location tends to be closer to the IMC layer near the Cu base side.Ni instead of Cu as the matrix can slow down the growth rate of the interface layer,and improve the reliability of Cu-core solder joints.Highlights:(1)The atomic migration and interfacial reaction of Ni/Cu-core+Solder/Cu Cu-core solder joints under thermal aging conditions were studied.

关 键 词：铜核焊点 界面反应 金属间化合物 生长行为 热时效 

分 类 号：TG425[金属学及工艺—焊接]