Experimental study on flow optimization and thermal performance enhancement of an ultrathin silicon-based loop heat pipe

Excessive heat flux of integrated circuits (ICs) leads to the failure of electronic devices and the consumption of extra energy. Silicon-based loop heat pipe (sLHP) offers a simple, reliable and easily-integrate method for IC thermal management. In this study, the influence of two common wicks (micropillar arrays (MP) wick and microchannel (MC) wick) on fluid flow and performance of sLHP are systematically compared and studied through visual experiment. And two advanced wicks (in-line long rib (IR) wick and staggered long rib (SR) wick) are proposed to further optimize the sLHP. The results show that the fluctuant vapor-liquid interface in MP wick is beneficial to the supplement of working fluid from adjacent flow channel, but it also introduces the uncertainty of flow. The MC wick features the preset flow channel and stable fluid flow but limited heat transfer capacity. Notably, the IR wick and SR wick effectively enhance that capability of supplementing fluid by combining the advantages of the MP wick and MC wick showing better thermal performance. The effective thermal conductivity of SR-sLHP and IR-sLHP is better than that of MP-sLHP and MC-sLHP, with the maximum values of 860 W/(m & sdot;K) & sdot; K) and 848 W/(m & sdot;K), & sdot; K), respectively.