Occurrence of Electromigration at High-Pb/Eutectic Solder Interface

• Main Author: 賴璟亮
• Other Authors: Chih Chen
• Format: Others
• Language: en_US
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/32761218891562411095

碩士 === 國立交通大學 === 材料科學與工程系 === 90 === The electromigration behavior in high-Pb/eutectic composite solder lines were studied in this experiment. Using Si V-grooves, we simulated the composite solder structure by reflowing the two solders into it. Electromigration effect was studued as a function of temperature, and stressing direction. Various of electromigration damage was observed when current direction or stressing temperature changed. If the electron flux was passed from the eutectic solder side to the high-Pb solder side, hillocks formed at the eutectic/high-Pb solder interface and the voids appeared at the cathode side. When the electron flux was passed from the high-Pb to the eutectic solder side, the hillock accumulated at the anode side near the Cu/eutectic solder interface, and voids were formed at the cathode side both at room temperature and 150°C. We observed a trench along Cu/high-Pb interface whether stressing or not at 150°C. The depth is about several microns. But, the trench is not found at Cu/eutectic solder interface; it may due to the eutectic solder is more ductile than high-Pb solder.