Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.
In this study, thermal performance and flow visualization of
a double layer flat micro vapor chamber are carried out. Two
micro vapor chambers having pin fin and pin fin array support
structure were fabricated and tested. The micro vapor chambers
were composed of silicon and glass wafers having an overall
size of 35 mm × 40 mm × 1.525 mm. Test results show that
both the pin fin and pin fin array vapor chambers show
appreciably lower thermal resistance as compared to the solid
silicon counterpart, the thermal resistance of the pin fin vapor
chamber is about 52-60% of the solid silicon whereas the
corresponding thermal resistance of pin fin array is only 17-20
% of the solid silicon. The thermal resistance of the pin fin
vapor chamber is moderately increased with the increase of
supplied power whereas opposite trend is encountered for the
pin fin array. The phenomenon is associated with the influence
of dry-out phenomenon. It is found that the pin fin array vapor
chamber is still in function even for an upside-down
arrangement. The thermal resistance, however, is reduced with
the rise of tilt angle, and the vertical arrangement gives the
lowest thermal resistance. However, the thermal resistance is
considerably increased if the heat source is placed upwards, and
the corresponding thermal resistance for an upside-down heat
source can be threefold higher than that of the vertical
arrangement.
