An isothermal heat sink use operational principles of heat pipes and includes
a plate-like body including a housing, an interior partition and a wick. The housing
has an inner chamber under a vacuum. The interior partition divides the inner chamber
into an upper and lower half chamber and has a central through hole and multiple
air passages. The wick containing a working fluid is held in the central through
hole and has a lower evaporating section and an upper condensing section that are
held respectively in the lower and the upper half chambers. Therefore, the working
fluid in the evaporating section evaporates and produces a vapor that enters the
upper half chamber from the lower half chamber through the air passages. The vapor
condenses into liquid that enters the condensing section and returns to the evaporating
section to improve cooling efficiency of the heat sink.
