Integrating electrothermal coupling analysis in the calibration of experimental electromigration reliability of flip-chip packages

Abstract

The electromigration reliability of solder interconnects is dominated by the current density and the temperature inside the interconnects. For flip-chip packages, current densities around the regions where traces connect a solder bump increase by a significant amount owing to the differences in feature sizes and electric resistivities between the solder bump and its adjacent traces. This current crowding effect along with induced Joule heating accelerates electromigration failures. In this paper, effects of current crowding and Joule heating in a flip-chip package are examined and quantified through a three-dimensional electrothermal coupling analysis. We apply a volumetric averaging technique to cope with the current crowding singularity. The volumetrically averaged current density and the maximum temperature in a solder bump are integrated in the Black's equation to calibrate experimental electromigration fatigue lives.

Research on the Reliability of Advanced Packaging under Multi-Field Coupling: A Review

“…This information can be used to select more suitable materials, optimiz the dimensions, shapes, and layouts of the bumps, and reduce the risk of electromigration Lai was the first to apply electrothermal coupling analysis to predict the electromigration lifetime of FC structures. By applying a constant current to a series of daisy-chain solde bumps, the calculated current crowding and Joule heating effects were integrated into Black's equation [60]. This method was then used to study the Joule heating and curren crowding effects in three types of FC bumps [61], as shown in Figure 15a.…”