Design and fabrication of flat heat pipes with different length

In this paper, two SOG structure micro heat pipes array (MHPs) with different length were fabricated, filled and tested. The MHPs were fabricated employing a silicon anisotropic etch technique. A new fill technology was used to inject the working fluid. The experiments were carried out to compare the effects of fluid fill rates between two MHPs with different length. The results revealed that for the long MHPs the highest heat transfer capacity exists with the fill ratio of 35% and for the short one the optimal fill ratio is 45%. The temperature profiles are also considered for two kinds of MHPs respectively. The results indicated that the long MHPs and the short MHPs have nearly the same heat transfer capacity with their optimal fill ratio repectively.