Investigation of Electromigration Reliability of Flip-chip Packages by Electrothermal Coupling Analysis

• Main Authors: Chin-LiKao, 高金利
• Other Authors: Tei-Chen Chen
• Format: Others
• Language: en_US
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/n7pb8c

博士 === 國立成功大學 === 機械工程學系 === 106 === The electromigration reliability of solder interconnects is dominated by current density and 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 adjust the experimental electromigration fatigue lives. In addition, the effects of the solder bump structure, Sn-37Pb and Sn-Ag-Cu solder bump composition, and UBM composition on the electromigration characteristics are investigated.