【摘要】 主要研究电流密度为5×103A/cm2,室温和高温(100℃)条件下共晶SnBi焊点的电迁移特性。结果表明:室温条件通电465h后,阳极界面处出现Bi的挤出,阴极界面处出现裂纹;而在高温条件下通电115h后,组织形貌发生了很大的变化。高温加速了阴极钎料的损耗,导致电流密度在局部区域高度集中,从而产生更多的焦耳热,最终引发焊点的熔化。熔融状态下Sn原子与Cu反应,在基体形成大量块状的Cu6Sn5金属间化合物,严重降低焊点的可靠性。更多还原

【Abstract】 Electromigration (EM) behavior of eutectic SnBi solder joint was investigated with current density of 5×103 A/cm2 at room temperature and high temperature (100 oC).Results indicate that the Bi atoms were extruded out of the anode interface and cracks were formed at the cathode interface after 465 h current stressing at room temperature.However,the microstructure of eutectic SnBi solder joint changed much at high temperature after 115 h current stressing.Cu3Sn,Cu6Sn5 and Bi layers were formed at the anode in sequence,and the crack propagated through the whole cathode interface.Solder depletion at the cathode was accelerated after applying such a high temperature,leading to higher current density in some local regions which could produce much more Joule heating and finally induce the melting.At molten state,Sn reacted with Cu to form a number of Cu6Sn5 bumps in the central solder matrix which reduced the reliability of the solder joint.更多还原