Two-Phase Liquid Cooling for High-Power Microelectronics via Embedded Micro-Pin Fin Heat Sink

Two-phase liquid cooling can achieve high heat flux and is therefore a key method for heat dissipation of high-power microelectronics. In this study, we develop an embedded two-phase liquid cooling solution with micro-pin fins embedded in a thermal test vehicle (TTV). We conduct experimental tests under various coolant (deionized (DI) water) flowrates and heat fluxes. Heat fluxes up to 181 W/cm2 (heat power 181 W) are achieved at small coolant flowrates. Chip temperature and system pressure in the two-phase regime fluctuate. By degassing the coolant prior to experimental testing, the chip temperature fluctuation span can be reduced to as low as 7.6 °C. The pressure fluctuation is also greatly suppressed. These results are beneficial for the practical application of two-phase liquid cooling in microelectronics, where chip temperature fluctuations may damage chips due to temporal overheating. In addition, the temperature and temperature gradient of chip linearly increase with increasing heat flux. They both can be reduced by increasing coolant flowrate. As coolant flowrate increases, the heat flux at which two-phase cooling occurs also increases. The present results demonstrate the effectiveness of embedded two-phase liquid cooling, which can facilitate our next step to develop embedded two-phase liquid cooling for true 3-D ICs (i.e., two-layer stacked chips).