Baseplate Temperature Gradient-Based Health Status Monitoring for Power Module Bonding Wires

The widespread adoption of power modules in power electronics has elevated reliability to a critical research priority. Bonding wires, serving as pivotal components within these modules, profoundly influence performance and longevity when fractured or lifted off. Complete fracture of all bonding wires on a chip occurs after long-term operation, which may be accelerated under extreme operational conditions, inducing internal current redistribution and consequential shifts in temperature distribution. To mitigate this challenge, this study introduces a method for monitoring the health status of power module bonding wires through variations in baseplate temperature gradients. Unlike conventional approaches, the proposed method monitors the bonding-wire degradation fault via externally measuring temperatures on the baseplate; this non-invasive technique provides both effectiveness of monitoring and ease of implementation. By conducting finite-element analysis, the correlation between baseplate thermal distribution patterns and health status of bonding wires is investigated. Experimental results confirm that the proposed method effectively identifies and locates complete lift-off of all bonding wires on a chip, enabling real-time status assessment of power modules for high-reliability application scenarios and offering a practical way for power converter system maintenance.