Experimental studies of copper porous microfin composite structures for immersion phase-change liquid cooling

Abstract

Currently, the rapid development of digital economy and artificial intelligence urgently needs a dramatic increase in computing power, posing a huge challenge to develop advanced microporous copper materials for chip cooling. However, the maximal heat flux (q_max) of copper micro/nanostructures reported by all peers for immersion phase-change liquid cooling (IPCLC) is only 59 W cm⁻² with the surface temperature (T_S) of simulated chip heat source reaching the upper limit of 85 °C. Here, we report a novel copper porous microfin (CPMF) composite structure with IPCLC performance outperforming those of all peers’ reported micro/nanostructures. Through the rational design of geometrical parameters, its q_max can reach 76 W cm⁻² with T_S being 69 °C, much lower than the allowable upper limit of chip case temperature. Such remarkable IPCLC performance originates from the skillful trade-off among rich nucleation sites, low interface thermal resistance, strong capillary liquid supply and innate vapor-liquid separation of the optimal CPMF composite structure heat sink featured with small microspheres, dense and short porous microfins, and properly-thick porous underlayer. This work not only helps deepen understanding into how hierarchical microporous structures rationally design to enable efficient IPCLC but also provides an advanced IPCLC solution with practical prospect.