Experimental study on thermal performance of loop heat pipes with flat evaporator for LSI package

Thermal performance of a loop heat pipe (LHP) equipped with a flat evaporator and a compensation chamber integrated onto the evaporator and separated from the evaporator was experimentally investigated. The heat leak in the flat evaporator is a critical problem as it results in the degradation of the heat transport characteristics of the LHP. In this paper, the heat leak quantity during the steady-state operation of the LHP was calculated by carrying out a thermal energy balance analysis for the flat evaporator. From the results, the heat conduction along the case sidewall of the evaporator dominated the heat leak on the evaporator, and it was found that the heat leak from the heat source to the compensation chamber decreased to 5% or less of the applied input power due to the reduced heat conduction of the evaporator casing.