Flat miniature heat pipes with micro capillary grooves

Flat miniature heat pipes (FMHP's) are shown to be very promising in the co oling of electronic component systems. This investigation presents a detail ed experimental mid theoretical analysis on maximum heat transfer capabilit ies of two copper-water FMHP's with diagonal trapezoidal micro capillary gr ooves and one copper-water FMHP with axial rectangular micro capillary groo ves. Maximum heat flux an the evaporator wall of the 120-mm long axial groo ved heat pipe, with a vapor channel cross-sectional area of approximately 1 .5 x 12 mm(2) and rectangular grooves of dimensions 0.20 mm wide by 0.42 mm deep, exceeded 90 W/cm(2) in the horizontal orientation and 150 W/cm(2) in the vertical orientation. Theoretical prediction of the capillary limitati on in the horizontal orientation agreed reasonably well with the experiment al data.