Effects of bulk Cu6Sn5 intermetallic compounds on the properties of Sn‐Ag‐Cu‐Ce soldered joints
Abstract
Purpose
The purpose of this paper is to explore the formation and growth mechanism of bulk Cu6Sn5 intermetallic compounds, selecting Sn‐Ag‐Cu‐Ce solders as specimens.
Design/methodology/approach
In order to further enhance the properties of SnAgCu solder, trace amount of rare earth Ce was selected as alloying addition into the alloy; in previous investigations, the enhancements include better wettability, physical properties, creep strength and tensile strength. In this paper, the microstructure of Sn‐Ag‐Cu‐Ce soldered joints and its interfacial intermetallic compounds were investigated. Moreover, different morphologies of Cu6Sn5 IMCs were enumerated and described, and Ostwald ripening theory was employed to interpret the formation mechanism of bulk Cu6Sn5 IMCs.
Findings
In addition, based on finite element simulation, it is found that the von Mises stress concentrate around the bulk Cu6Sn5 IMCs inside the Sn‐Ag‐Cu‐Ce soldered joints after three thermal cycling loading (−55‐125°C). From the stress distribution, the failure site was predicted to fracture near the bulk Cu6Sn5 IMCs interface. This coincides with the experimental findings significantly.
Originality/value
The results presented in this paper may provide a theory guide for developing novel lead‐free solders as well as reliability investigation of lead‐free soldered joints.
Keywords
Citation
Zhang, L., Xue, S., Gao, L., Sheng, Z., Dai, W., Ji, F., Ye, H., Chen, Y. and Yu, S. (2011), "Effects of bulk Cu6Sn5 intermetallic compounds on the properties of Sn‐Ag‐Cu‐Ce soldered joints", Soldering & Surface Mount Technology, Vol. 23 No. 1, pp. 4-9. https://doi.org/10.1108/09540911111099640
Publisher
:Emerald Group Publishing Limited
Copyright © 2011, Emerald Group Publishing Limited