Multi-Physics Coupling-Based Optimization of Igbt Bonding Wire Geometric Parameters and Thermomechanical Effect Analysis

The failure of bonding wires in Insulated Gate Bipolar Transistors (IGBTs) is a critical challenge limiting the reliability of power modules, where their thermo-mechanical performance is strongly influenced by geometric parameters. This study establishes a three-dimensional electro-thermal-mechanical coupling model using the COMSOL multi-physics simulation platform to quantitatively investigate the effects of bonding wire parameters-including arch height, span, and diameter/number combinations-on chip temperature and interfacial stress. Key findings reveal that: (1) Optimizing the bonding wire arch height within the range of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{1.2 - 1.5 mm}$</tex> enables synergistic optimization of chip temperature rise and interfacial shear stress; (2) Increasing the bonding wire span significantly elevates stress concentrations at the wire roots; (3) A multi-strand fine-wire bonding scheme (e.g., 0.175 mm diameter <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\times 6$</tex> wires) effectively reduces both chip temperature and interfacial stress compared to coarse-wire configurations with fewer strands. The study elucidates the regulatory mechanisms of bonding wire geometric parameters on multi-physics field distributions, providing a theoretical foundation for designing high-reliability IGBT packaging and optimizing manufacturing processes.