菊花链互连电迁移多物理场模拟仿真

Multi-physical Field Simulation of Electromigration of Daisy-chain Interconnect

菊花链结构键合凸点在三维封装领域具有广泛应用前景,其电迁移失效现象成为电子封装领域重点关注的问题。建立了球形及方形凸点互连模型,在电-热耦合场作用下,观察互连结构的电流密度分布及温度分布。发现在铝布线进出凸点的位置容易发生电流聚集现象,此处方形凸点电流密度较球形凸点低;方形凸点温度变化幅度较球形凸点低。此外,仿真分析了1mA~3mA输入电流及不同凸点尺寸对电迁移失效的影响。发现相同条件下,大尺寸方形凸点的电迁移可靠性高,为凸点结构设计提供了依据。

Daisy-chain bonding bumps are widely used in 3D packaging,and their electromigration failure has become an im⁃portant problem in the field of electronic packaging.The interconnection models of spherical and square bumps are established.The current density distribution and temperature distribution of the interconnect structures are observed under the effect of electric-ther⁃mal coupling field.It is found that current aggregation is easy to happen in the joint of bumps and aluminum wiring.The current den⁃sity of the square bumps is lower than that of the spherical bumps.The temperature variation extent of square bumps is lower than that of spherical bumps.In addition,the effects of 1mA~3mA input current and different bump size on electromigration failure are simulated and analyzed.It is found that under the same conditions,the reliability of electromigration of large square bumps is high,which provides a basis for the design of bump structure.