Influence of bonding temperature on the properties of Cu/(SAC mixed powder)/Al joints under ultrasonic-assisted
Soldering & Surface Mount Technology
ISSN: 0954-0911
Article publication date: 24 January 2023
Issue publication date: 30 June 2023
Abstract
Purpose
This study aims to research properties of Cu/SAC0307 mixed solder balls/Al joints with different bonding temperature under ultrasonic-assisted.
Design/methodology/approach
A new method that 1 mm Zn particles and Sn-0.3Ag-0.7 (SAC0307) with a particle size of 25–38 mm were mixed to fill the joint and successfully achieved micro-joining of Cu/Al under ultrasonic-assisted.
Findings
The results indicated that when the bonding temperature was 180°C, there was only one layer of CuZn5 intermetallic compounds (IMCs) at the Cu interface. However, when the bonding temperature was 190°C, 200°C and 210°C, the Cu interface IMCs had two layers: for one layer, the IMCs near the Cu substrate were Cu5Zn8 and for another layer, the IMCs near the solder were CuZn5. In addition, the thickness of the Cu interfacial IMCs increased with the bonding temperature. In particular, the thickness of IMCs at the Cu interface of the Cu/Al joints soldered at 210°C was 4.6 µm, which increased by 139.6% compared with that of the Cu/Al joints soldered at 180°C. However, there was no IMC layer at the Al interface, but there might be a Zn–Al solid solution layer. The shear strength of Cu/Al joints soldered at 180°C was only 15.01 MPa, but as the soldering temperature continued to increase, the shear strength of the Cu/Al joints increased rapidly. When the soldering temperature was 200°C, the shear strength of the Cu/Al joints reached the maximum of 38.07 MPa, which was 153.6% higher than that at 180°C. When the soldering temperature was 180°C, the fracture of Cu/Al joints was mainly on the Al side. However, when soldering temperature was 190°C, 200°C and 210°C, the fracture of Cu/Al joints was mainly broken in the Zn particles layer.
Originality/value
A new method that 1 mm Zn particles and Sn-0.3Ag-0.7 (SAC0307) with a particle size of 25–38 mm were mixed to fill the Cu/Al joint at 210°C.
Keywords
Acknowledgements
This work was supported by the National Natural Science Foundation of China (Grant Nos. 61974013 and 62274020), the China Postdoctoral Science Foundation (No. 2022MD713756), the Scientific and Technological Research Program of Chongqing Municipal Education Commission (No. KJZD-K202101101), 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.-q., Jiang, L., Liu, C., Ma, P., Huang, T., Cheng, D. and Liu, X. (2023), "Influence of bonding temperature on the properties of Cu/(SAC mixed powder)/Al joints under ultrasonic-assisted", Soldering & Surface Mount Technology, Vol. 35 No. 4, pp. 189-198. https://doi.org/10.1108/SSMT-07-2022-0047
Publisher
:Emerald Publishing Limited
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