A heat sink assembly for cooling an electronic device comprises a fan
housed in a shroud, the fan including a hub and fan blades extending
therefrom for causing an axially directed airflow through the shroud upon
rotation of the fan blades. A thermosiphon comprises an evaporator
defining an evaporating chamber containing a working fluid therein and
further including a condenser mounted thereabove. The thermosiphon is
positioned at one end of the shroud such that the fan is aligned with the
condenser for directing the axial airflow therethrough. The condenser
includes a base having an upper surface and a plurality of fins extending
substantially upwardly from the upper surface. The condenser also includes
a plurality of tubes forming a tube grouping. Each tube having an opening
in fluid communication with the evaporator and for receiving and
condensing vapor of the working fluid received from the evaporator. The
tubes are axially aligned with the airflow and are laterally positioned
such that a lateral width of the tube grouping is approximately equal to a
width of the hub and substantially in lateral alignment therewith.
