Thermal Fatigue Reliability of Silicon-Based Thermal Management Devices

With the continual rise in device power density, the thermal–fatigue reliability of silicon‐based embedded microchannel coolers under thermal cycling has become increasingly critical. In this study, a three-dimensional thermo-fluid-structural coupled finite-element model was developed in COMSOL to simulate the thermal stress distribution under temperature cycles from -25 °C ~ 125 °C. By integrating the Miner damage model with fracture-mechanics theory, we quantitatively assessed how geometric dimensional parameters affect the fatigue life of the bonding layer. The results show that structural dimensions exert a significant influence on thermal‐stress concentration, crack‐initiation risk, and fatigue life; for instance, when the fin measures 50 μm × 300 μm, the peak von Mises stress reaches 31.5 MPa, corresponding to an estimated failure at ~2,200 cycles. Furthermore, increasing the fin depth‐to‐width ratio yields an exponential decline in fatigue life. This work is the first to systematically elucidate the relationship between microstructural dimensions and fatigue performance in silicon‐based thermal‐management devices, providing both theoretical insight and simulation tools for design optimization and reliability enhancement.