An Energy-efficient Si-integrated Micro-cooler for High Power and Power-density Computing Applications

A Si-integrated direct liquid cooling solution, IMC-Si (Si-Integrated Micro-Cooler), has been developed to address high power and power-density demand in high performance computing (HPC) applications. The proposed cooling architecture can dissipate a great amount of heat yet at a little cost of energy consumption, making it an environment-sustainable cooling technology for high-power computing applications. The IMC-Si leverages the well-established SoIC ® technology for fabrication processes and is suitable for mass production. The egg-shaped micropillars are formed on the backside of a silicon carrier and their arrays are compartmentalized to "divide & conquer" the heat. Moreover, the IMC-Si is fully compatible with TSMC 3D Fabric™ platform, such as CoWoS ® and InFO, given its monolithic nature as part of the SoC. Experimental results showed that the IMC-Si can cool a near full-reticle die with a uniform TDP of 2 kW (power density = 3.2 W/mm 2 ) when using 40°C water as the coolant. The required pumping power is much lower than 10 W, leading to ultra-low PUE performance. The highest power density of hot spots (1 mm 2 ) can be as high as 14.6 W/mm 2 under the same operating conditions. Furthermore, as the TDP is reduced to 0.8 kW, a local hot spot of power density higher than 20 W/mm 2 can be easily managed at the same pumping cost. Therefore, the IMC-Si exhibits great potential for co-design optimization between micropillar arrangement and circuit placement for high power-density applications.