Electromigration tests in Cu/SnAg/Ni/Cu Flip Chip solder joints and Cu/SnAg/Cu microbumps

• Main Authors: Liu, Shun Cai, 劉順財
• Other Authors: Chen, Chih
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/95944968763845461265

碩士 === 國立交通大學 === 材料科學與工程學系所 === 103 === Due to the growing demands for high performance, small form factor and multi-functions in microelectronic packaging for different types of portable electronic devices, 3D stacking is an important issue nowadays in ICs industry. The first part of this study was the electromigration test using two different bump heights (15 μm and 30 μm) of Cu/SnAg/Ni/Cu flip-chip samples. We can investigate the effect of the bump height effect of failure mode in electromigration. The current density of the experimental conditions is 1.33x104 A/cm2, 1.45x104 A/cm2 and 1.57x104 A/cm2, we can observe the failure mode is void formation, when Ni UBM at the cathode side. When the anode with Cu UBM, we also found serious copper dissolution. The second part is electromigration test of Cu/8 μm SnAg/Cu microbumps. The test temperatures were 135 °C, 150 °C and 165 °C on hot plates. We found some sample had early failure, and further explored the reasons for the failure, then we can avoid the early failure. The third part is about Cu/8 μm SnAg/Cu microbumps reflowing at different times. The microbumps were reflowed on a 260 °C hot plate for 0, 5, 10, 20, and 40 min to investigate the variation of Ag concentration in the residual SnAg solder and the morphology of Ag3Sn precipitations.