Influence of aging temperature on the properties of Cu/(SAC0307 powder +Zn-particles)/Al joints ultrasonic-assisted soldered at low temperature
Soldering & Surface Mount Technology
ISSN: 0954-0911
Article publication date: 25 October 2022
Issue publication date: 21 April 2023
Abstract
Purpose
This study aims to evaluate the effect of thermal aging temperature on the properties of Cu/Al joints.
Design/methodology/approach
A new method in which 1 µm Zn-particles and SAC0307 with a particle size of 25–38 µm were mixed to fill the joint and successfully achieved the micro-joining of Cu/Al under ultrasonic-assisted at 200°C, and then, the effect of aging temperature on the properties of Cu/Al joints at different aging times was researched.
Findings
The results showed that the Cu interface intermetallic compounds (IMCs) had the same composition and had two layers with Cu5Zn8 near the Cu substrate and CuZn5 near the solder. As the aging time increased, CuZn5 gradually transformed to Cu5Zn8, and the thickness of the CuZn5 layer gradually decreased until CuZn5 disappeared completely. There was a Sn–Zn solid solution at the Al interface, and the composition of the Al interface of the Cu/Al joints did not change with changing temperature. The IMC thickness at the Cu interface of the joints continued to increase, and the shear strength of the Cu/Al joints decreased with increasing aging temperature and time. Compared with the as-received samples, the IMC thickness of the Cu interface of joints increased by 371.8% and the shear strength of the Cu/Al joints was reduced by 83.2% when the joints were aged at 150°C for 24 h. With an increase in aging temperature, the fracture mode of the Cu/Al joints changed from being between solder balls and Zn particles to between Zn particles.
Originality/value
With increasing aging temperature, the shear strengths of the Cu/SACZ/Al joints decreased at the same aging time, the shear strength of Cu/SACZ/Al joints at 150°C for 24h decreased by 83.2% compared with that of the as-received joints.
Keywords
Acknowledgements
This work was supported by the National Natural Science Foundation of China (Grant No.61974013 and 62274020) and the China Postdoctoral Science Foundation (NO. 2022MD713756), the Scientific and Technological Research Program of Chongqing Municipal Education Commission (NO.KJZD-K202101101) and Chongqing Research Program Basic Research Frontier Technology (cstc2020jcyj-msxmX0819), University Innovation Research Group of Chongqing (CXQT20023) and Graduate Innovation Project of Chongqing University of Technology (gzlcx20223016 and gzlcx20223023).
Citation
Gan, G., Chen, S., Jiang, L., Xu, Q., Huang, T., Cheng, D. and Liu, X. (2023), "Influence of aging temperature on the properties of Cu/(SAC0307 powder +Zn-particles)/Al joints ultrasonic-assisted soldered at low temperature", Soldering & Surface Mount Technology, Vol. 35 No. 3, pp. 155-165. https://doi.org/10.1108/SSMT-04-2022-0027
Publisher
:Emerald Publishing Limited
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