Effect of Electromigration on Interfacial Reaction of Cu/Sn3.0Ag0.5Cu/Ni Solder Joint at High Temperature
The Cu/Sn3.0Ag0.5Cu/Ni (Cu/SAC305/Ni) solder joints were designed to investigate the Cu, Ni atoms diffusion behavior and the interfacial reaction during electromigration (EM) at 180 ℃ under a current density of 1.0×104 A/cm2. For comparison, the Cu/Sn3.0Ag0.5Cu/Ni solder joints were aged at 180 ℃ for the same durations. In as-soldered state, the (Cu0.55Ni0.45)6Sn5 and (Cu0.92Ni0.08)6Sn5 IMCs formed at the SAC305/Ni and SAC305/Cu interfaces, respectively. The interfacial IMC thickness increased with increasing aging time. During EM, the current direction played an important role on Cu consumption. When electrons flowed from PCB side to chip side, the Cu pad dissolved into the solder and microcrack formed at the solder/Cu interface. The dissolved Cu atoms were driven toward the anode side and precipitated as large Cu6Sn5 IMCs in the solder matrix along the flowing direction of electrons. While when electrons flowed from chip side to PCB side, no Cu pad consumption was observed and a thick layer-type Cu6Sn5 IMC formed at the SAC305/Cu interface; the thickness of the interfacial IMCs increased with increasing EM time and increased to 15.90 μm after EM for 100 h. As to Ni UBM, no significant consumption of Ni was observed even electrons flowed from chip side to PCB side. Ni UBM was more resistant than Cu UBM during EM. After EM for 143 h, the solder joint failed due to the melting of the SAC305 solder bump
Leida Chen Mingliang Huang Shaoming Zhou Song Ye Yuming Ye Jifan Wang Xi Cao
Electronic Packaging Materials Laboratory, School of Materials Science & Engineering,Dalian Universi Huawei Technologies Co., Ltd., Shenzhen 518129, China
国际会议
上海
英文
316-320
2011-08-08（万方平台首次上网日期，不代表论文的发表时间）