针对无铅互连电迁移失效这一高密度封装时面临的重要课题进行了研究.采用四探针法分别监测了电流密度为1.5×104A/cm2和2.2×104A/cm2时Sn3.5Ag0.5Cu互连凸点上电压的变化,发现电流密度为2.2×104A/cm2时凸点的平均电阻变化率超过电迁移失效的临界值10%,分析了其微观结构的扫描电镜照片,所提出的发生电迁移失效的电流密度值为凸点设计提供十分有用的数据.对无铅互连凸点的电迁移失效过程和四探针测量法的测量误差进行了分析,提出了采用四凸点结构提高测量精度的改进措施. Aiming at the important issues in the high-density packaging of lead-free interconnection electromigration, the four-probe method was used to monitor the current density of 1.5 × 104A / cm2 and 2.2 × 104A / cm2 Sn3.5Ag0.5Cu It is found that when the current density is 2.2 × 104 A / cm2, the average resistance change rate of the bumps exceeds the critical value of electromigration failure by 10%. The scanning electron micrographs of the microstructures are analyzed. The current densities of electromigration failure provide very useful data for the design of bumps.Electro-migration failure process of lead-free interconnection bumps and the measurement error of four-probe measurement method are analyzed, and the four-bump structure is proposed to improve Measurement accuracy improvement measures.