1. Microstructure and Properties of Electromigration of Sn58Bi/Cu Solder Joints with Different Joule Thermal Properties.
- Author
-
Gao, Yijie, Zhang, Keke, Zhang, Chao, Wang, Yuming, and Chen, Weiming
- Subjects
SOLDER joints ,ELECTRODIFFUSION ,THERMAL properties ,COPPER-tin alloys ,BRITTLE fractures ,MICROSTRUCTURE - Abstract
Electromigration is one of the most important research issues affecting the reliability of solder joints. Current-induced Joule heating affects the electromigration behavior of solder joints. Solder joints with different cross-sectional areas were designed to obtain different Joule heating properties. The effects of the interfacial intermetallic compound (IMC) and mechanical properties of Sn58Bi/Cu solder joints were studied for different Joule heating properties. The results showed that as the cross-sectional area of the Sn58Bi/Cu solder joints increased, the Joule heating of the joint increased. The anode IMC thickness of the joint thickened and transformed into a planar shape. The Bi migrated to the anode region to form a Bi-rich layer and gradually increased in thickness. The cathode IMC thickness first increased, then decreased, and gradually dissolved. The Sn-rich layer formed near the solder side and gradually increased in thickness, with microcracks occurring when the cross-sectional area of the joint increased to 0.75 mm
2 . The joint shear fracture path moved from the soldering zone near the cathode IMC layer to the interfacial IMC layer. The fracture mechanism of the joint changed from a mixed brittle/tough fracture, dominated by deconstruction and secondary cracking, to a brittle fracture dominated by deconstruction. The joint shear strength was reduced by 60.9% compared to that in the absence of electromigration. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF