Hetero-connecting materials effect on the electromigration and thermalmigration of SnBi solder joints
As the designs of electronic products were tended to be miniaturized and highly integrated,the electromigration of solder joints becomes a major issue due to the increasing current density.It is demonstrated that,the electromigration effect of solder joints could induce the microstructure evolution and failure in solders at high current densities.At the same time,a large quantity of Joule heat generated during electromigration,which leads to non-uniform distribution of temperature and thermal migration.Electromigration and thermal migration are the main factors that cause solder joint failure.The aim of this paper is to explore the hetero-connecting materials effect on SnBi solder joints under the effects of electrical and thermal field.The linear Sn58Bi solder joints which have different substrates were utilized in this paper.The peak reflow temperature for soldering was 205℃.The differences of the main element migration between the Cu/Ni joints and the Cu/Cu joints were compared and the failure behavior of each structure above was discussed,respectively.The morphology and element distribution were characterized by SEM and EDX analysis.It is showed that the migration of Cu atoms was retarded and Cu atoms rarely appeared inside of the solder joints of Cu/SnBi/Cu.On the other hand,Cu atoms were migrated significantly faster than Bi atoms,in Cu/Sn58Bi/Ni solder joints.The reason of that was Cu/SnBi/Ni solder joints had a stable IMC(Cu,Ni)6Sn5 due to the Ni atoms migrating to the solder joints from the substrate,which suppressed the crack propagation and cracking of Cu6Sn5,and thus effectively delayed failure behaviors compared to Cu/SnBi/Cu solder joints.
electromigration and thermal migration failure behavior SnBi solder joint
Ming Liu Limin Ma Fu Guo Yishu Wang Jing Han
The College of Materials Science and Engineering,Beijing University of Technology 100 Ping Le Yuan,Chaoyang District,Beijing 100124,P.R.China
国际会议
上海
英文
109-111
2018-08-08（万方平台首次上网日期，不代表论文的发表时间）