Thermal Induced Interface Mechanical Response Analysis of SMT Lead-Free Solder Joint and Its Adaptive Optimization
Authors
Liu, ShaoyiYan, Yuefei
Zhou, Yijiang
Han, Baoqing
Wang, Benben
Zhang, Daxing
Xue, Song
Wang, Zhihai
Yu, Kunpeng
Shi, Yu
Wang, Congsi
Affiliation
Xidian University; CETC No. 38 Research Institute; University of ChesterPublication Date
2022-06-08
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Surface mount technology (SMT) plays an important role in integrated circuits, but due to thermal stress alternation caused by temperature cycling, it tends to have thermo-mechanical reliability problems. At the same time, considering the environmental and health problems of lead (Pb)-based solders, the electronics industry has turned to lead-free solders, such as ternary alloy Sn-3Ag-0.5Cu (SAC305). As lead-free solders exhibit visco-plastic mechanical properties significantly affected by temperature, their thermo-mechanical reliability has received considerable attention. In this study, the interface delamination of an SMT solder joint using a SAC305 alloy under temperature cycling has been analyzed by the nonlinear finite element method. The results indicate that the highest contact pressure at the four corners of the termination/solder horizontal interface means that delamination is most likely to occur, followed by the y-direction side region of the solder/land interface and the top arc region of the termination/solder vertical interface. It should be noted that in order to keep the shape of the solder joint in the finite element model consistent with the actual situation after the reflow process, a minimum energy-based morphology evolution method has been incorporated into the established finite element model. Eventually, an Improved Efficient Global Optimization (IEGO) method was used to optimize the geometry of the SMT solder joint in order to reduce the contact pressure at critical points and critical regions. The optimization result shows that the contact pressure at the critical points and at the critical regions decreases significantly, which also means that the probability of thermal-induced delamination decreases.Citation
Liu, S., Yan, Y., Zhou, Y., Han, B., Wang, B., Zhang, D., Xue, S., Wang, Z., Yu, K., Shi, Y., & Wang, C. (2022). Thermal induced interface mechanical response analysis of SMT lead-free solder joint and its adaptive optimization. Micromachines, 13(6), 908. https://doi.org/10.3390/mi13060908Publisher
MDPIJournal
MicromachinesAdditional Links
https://www.mdpi.com/2072-666X/13/6/908Type
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2072-666Xae974a485f413a2113503eed53cd6c53
10.3390/mi13060908
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Except where otherwise noted, this item's license is described as https://creativecommons.org/licenses/by-nc/4.0/