Electromigration study in SnCu solder joints with Ti/Ni(V)/Cu thin-film under-bump-metallization and Cu substrate pad

• Main Authors: Chu Ming-Hui, 朱明慧
• Other Authors: Chih Chen
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/92906745573277833040

碩士 === 國立交通大學 === 材料科學與工程系所 === 96 === In this study, electromigration study in SnCu lead-free solder joints with thin-film under-bump-metallization and Cu substrate pad was conducted. We found that there was sever damage on the substrate side (anode side), and the damage on chip side (cathode side) was little. The damage on substrate side included void formation, dissolution of copper, and intermetallic compound formation. The voids almost separated Cu pad from the solder. We used microstructure analysis and 3-dimension simulation to investigate the electromigration mechanism in the area between Cu pad and solder. The higher diffusion rate of Cu in the SnCu solder was responsible for the serious void formation in the interface between Cu pad and the solder layers. Therefore, the surface becomes the weakest region during electromigration.