Numerical study on heat transfer behaviors in reflow soldering process

In electronic packaging technology, the thermal behavior during reflow soldering critically influences solder joint quality and even device reliability. This study proposes a finite element analysis (FEA)-based approach to simulate the temperature field in reflow soldering processes by integrating heat transfer mechanisms for convective coefficient determination. A simplified three-dimensional printed circuit board (PCB) assembly model was developed in Abaqus, focusing on thermal convection as the dominant heat transfer mode. The convective heat transfer coefficient was theoretically derived using nozzle jet flow characteristics and Reynolds number correlations, avoiding experimental dependency. Key parameters, including nozzle diameter, airflow velocity, and thermophysical properties of dry air, were incorporated as boundary conditions. The simulation results revealed transient temperature distributions, with peak temperatures reaching 213.7°C at 219 s and cooling to 110.7°C upon exiting the reflow oven. Validation against experimental temperature profiles demonstrated a maximum error of 10%, confirming the model’s accuracy. This method significantly reduces computational costs while maintaining reliability by simplifying complex furnace structures and adopting fixed convective coefficients. The findings provide a practical framework for optimizing reflow soldering processes under experimental constraints and highlight the applicability of theoretical heat transfer models in multiphysics simulations.