Experimental Demonstration of Pressure-Driven Flash Boiling for Transient Two-Phase Cooling

This work demonstrates transient cooling for high-heat-flux electronics using pressure-controlled flash boiling. Many advanced electronics packages demand rapid, high-heat flux removal under stringent spatial and temporal constraints such as limited lateral heat spreading area, sharp power delivery transients, and heterogeneous power dissipation among dies. Flash cooling achieved by rapid depressurization of liquid coolant is inherently transient and provides high initial peak cooling that can be used for adaptive cooling demanded by these advanced packages. A coolant loop thermal testbed has been constructed to perform rapid transient thermo-fluid experiments of flash cooling with methanol. This work provides insights into depressurization-based flash incipience, thermodynamic analysis of flash cooling, and the ability to provide transient cooling in two application settings. First, a vapor chamber able to adapt to high initial transients applicable for short-burst applications. Second, a co-designed convective chamber that supports simultaneous power delivery and heat extraction for high-performance wafer-scale systems. A prototype vapor chamber was tested to obtain results for overall cooling and flash incipience experiments. The results demonstrate the efficacy of flash cooling for transient thermal management and highlight directions for further research and necessary data to exploit this technique for future electronics applications.