Research on failure mechanisms of electronic circuits in hygrothermal environment: a multi-physics simulation-test synergy approach

High-temperature and high-humidity environments represent a critical environmental stress source, inducing progressive degradation and sudden failures in electronic systems, thereby threatening the reliability and safety of key electromechanical systems in aerospace, power transmission, and communication networks. To overcome the limitations of traditional lifespan assessment methods in capturing internal uneven humidity-thermal stress and locating localized weak points, this study proposes a simulation-testing synergistically driven failure analysis method and lifespan prediction framework for a typical electronic system. A humidity-thermal-stress multi-physics coupling simulation model is established to accurately identify failure-prone locations such as the plastic casing, potting compound, and chip wire bonds. Accelerated laboratory tests validate the simulation accuracy, clarify failure origins, and form a closed-loop analysis mechanism of “simulation–test”. Furthermore, by incorporating creep accumulation effects, the long-term impact of humidity-thermal stress is quantified. A spatially differentiated lifespan prediction model integrating humidity, heat, and creep coupling is developed. This model overcomes the limitation of traditional global models that only predict the overall average lifespan, enhances prediction accuracy, and enables components lifespan estimation. The proposed framework offers theoretical and technical support for lifespan assessment and robust design of high-reliability electronic equipment in humidity-thermal environments.