Thermal aging effects on the properties of the Cu/(SAC0307 powder + Zn-particles)/Cu joint ultrasonic-assisted soldered at low-temperature
Soldering & Surface Mount Technology
ISSN: 0954-0911
Article publication date: 26 August 2022
Issue publication date: 28 February 2023
Abstract
Purpose
This study aims to evaluate the effect of thermal aging temperature on the properties of Cu/Cu joints.
Design/methodology/approach
A new method that 1 um Zn-particles and Sn-0.3Ag-0.7Cu (SAC0307) with a particle size of 25–38 µm were mixed to fill the joint and successfully achieved the micro-joining of Cu/Cu under ultrasonic-assisted at low-temperature, and then the effect of thermal aging temperature on the properties of Cu/Cu joints was researched.
Findings
The composition of the intermetallic compounds (IMCs) on the upper and lower interfaces of Cu/SACZ/Cu joints remained unchanged, which was Cu5Zn8 in aging process, and the thickness of the IMCs on the upper and lower interfaces of the Cu/SACZ/Cu joints increased accordingly. Compared with the as-received joints, the thickness of the upper and lower interfaces IMCs of the soldering aged time for 24 h increased by 404.7% and 505.5% at 150ºC, respectively. The IMCs formation tendency and the IMCs growth rate of the lower interface are larger than those of the upper interface because the soldering seam near the IMCs at the upper and lower interfaces of the as-received joints were mostly white SAC0307 balls black Zn-particles, respectively. The growth activation energy of IMCs in the upper and lower interfaces is about 89.21 and 55.11 kJ/mol, respectively. Under the same aging time, with the increase of the aging temperature, the shear strength of Cu/SACZ/Cu joints did not change significantly at first before 150ºC. When the aging temperature reached 150ºC, the shear strength of the joints decreased significantly; the shear strength of the joints was the smallest at 150ºC for 24 h, which was 39.4% lower than that of the as-received joints because the oxidation degree of Zn particles in the joint with the increase of aging temperature and time.
Originality/value
Cu/Cu joints were successfully achieved under ultrasonic-assisted at low-temperature.
Keywords
Acknowledgements
This work was supported by the National Natural Science Foundation of China (Grant No.61974013) 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), respectively.
Citation
Gan, G., Chen, S., Jiang, L., Jiang, Z., Liu, C., Ma, P., Cheng, D. and Liu, X. (2023), "Thermal aging effects on the properties of the Cu/(SAC0307 powder + Zn-particles)/Cu joint ultrasonic-assisted soldered at low-temperature", Soldering & Surface Mount Technology, Vol. 35 No. 2, pp. 95-105. https://doi.org/10.1108/SSMT-04-2022-0028
Publisher
:Emerald Publishing Limited
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