Study of void formation due to electromigration in flip-chip solder joints using Kelvin bump probes and 3D Simulation

• Main Author: 張元蔚
• Other Authors: 陳智
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/34943534416703020213

碩士 === 國立交通大學 === 材料科學與工程系所 === 95 === Electromigration of flip-chip solder joints has been studied extensively in recent years. Voids formed at the solder in the vicinity of the entrance point of the Al trance for solder joints with thin film UBM. However, the nucleation and propagation of the voids is still not clear. For Al and Cu inter-connects, void nucleation and propagation during electromigration is monitored by resistance change. But the bump resistance is quite small compared with the resistance of the metallization traces. Therefore, daisy-chain structure cannot detect the slight changes in microstructure in the solder joint. In this study, we designed and fabricated Kelvin bump probe, and used it to monitor the bump resistance change during electromigration successfully. Three-dimensional (3D) finite element modeling was also performed to simulate the bump resistance increase due to void formation. This approach facilitates the systemic study of failure mechanism due to electromigration in flip-chip solder joints.