Investigation on electromagnetic and heat transfer coupling of heating susceptor for selective microwave hybrid soldering: 3D multi-physics simulation and experiment

Abstract

The utilization of microwave hybrid heating as an emerging technique in the field of low-temperature joining presents a notable benefit of delivering both selective and rapid heating, a feature that is not commonly observed in traditional soldering methods. However, due to the complex multi-physical coupling problem, the factors and mechanisms affecting the heating effect of the susceptors have not been clearly explained. To examine the effect of susceptor shape, size, and process parameters on heating efficiency, a numerical model of electromagnetic and thermal coupling was created to analyze silicon carbide susceptor heating under microwave action. The response surface method examined how microwave frequency, power, and exposure time affect susceptor heating efficiency. The model’s three process parameters are used to selectively heat Cu/SAC305/Cu joints, and the connection mechanism is studied. The results reveal that cylindrical susceptors heat more efficiently and uniformly than cubic ones. The heating efficiency is the highest when the height of the susceptor is 30 mm. Moreover, the heating effect is optimum at 2.45 GHz. Microwave power and exposure period positively linked with susceptor heating efficiency. The finite element simulation model shows that energy consumption at 2.45 GHz\\2 kW210 s is 78.38 % of that at 2.45 GHZ\\1 kW370 s, and the maximum temperature difference is 73.44 % of that at 2.45 GHz\\3k W\\90 s. MHS experiments show that as exposure duration increases, Cu6Sn5 grew and the growth orientation becomes consistent and perpendicular to the {0 0 0 1} family of crystal planes. Under process settings of 2.45 GHz \\ 2 kW \\ 210 s, the joint can achieve 16.55 MPa shear tensile strength. The results can serve as references for the study on selective microwave hybrid soldering and provide a new idea for selective and efficient soldering.