Thermal management of integrated circuits in energy systems: Flow boiling in microchannels with multiple ultra-high heat flux sources

A novel stochastic nucleation boiling model is introduced in this study to address instabilities arising from sudden phase transitions in high-power 3D integrated circuits (3DICs). Employing a numerical simulation framework that integrates fluid-solid heat transfer and the Volume-of-Fluid model, this work investigates flow boiling heat transfer in microchannels under ultra-high heat flux sources at mass fluxes of 400–800 kg/(m2·s). The proposed model is experimentally validated and applied to a micro-spiral flow boiling thermal management scheme, which is compared against square, circular, and rounded square microchannels using energy efficiency metrics. Results indicate that spiral microchannels significantly enhance bubble dynamics, facilitating stable liquid-vapor separation via centrifugal forces while mitigating wall dry spots. This design reduces junction temperatures by approximately 4–6 °C and improves the "efficiency index" by 43.9 % and the "area goodness factor" by 28.6 % compared to square microchannels. The spiral microchannel effectively regulates temperature gradients, ensuring a maximum temperature difference of 5.1 °C and minimizing thermal resistance to 0.00471 °C/W. The boiling heat transfer coefficient deviation between microchannel inner walls was under 1.8 %. These findings confirm the enhanced heat transfer capability, reduced thermal resistance, and improved energy efficiency of spiral microchannels, providing a reliable cooling solution for multiple ultra-high heat flux sources.