Microwave Module Process Simulation and Structural Optimization

High-power microwave modules are widely used in radar, communication, and other fields, with increasing demands for miniaturization, high power, and multifunctionality. This paper, based on finite element analysis methods, establishes a thermo-mechanical coupling model for microwave modules during the reflow soldering and parallel soldering processes. The temperature and stress distribution and variation characteristics are systematically analyzed. The results show that during the heating stage, the temperature at the edges of the microwave module is higher than that at the center, and the temperature on the top is higher than that on the bottom. In contrast, during the cooling stage, the temperature distribution is reversed. The stress at the corner solder joints is higher than that at the central solder joints, and the stress of individual Ball Grid Array solder joints is mainly concentrated around the interface between the solder paste and the solder ball. Through orthogonal experiments, the effects of solder ball material, frame thickness, and substrate thickness on solder joint stress were studied. The influence sequence of these factors on solder joint stress and the optimal parameter combinations were obtained, which provide guidance for the structural design and manufacturing of high-reliability microwave modules.