Air flow distribution in integrated circuit spot coolers

A heat removal apparatus for an electronic component, said apparatus comprising:

• a heat sink having a base portion to be put in thermal contact with said electronic component, said base portion having a plurality of parallel plate fins thereon, said fins being configured to provide a recess for a fan in such a way that at least a portion of at least some of said fins remain present beneath said fan, said fins being arranged in a row having a first fin on one side of said base and a last fin on an opposite side of said base, said first and last fins having at least one gap respectively therein for passage of air, said fins having gaps in central portions thereof so as to define an exhaust passage;
• a fan unit disposed within said recess, said fan unit having a central motor with fan blades which are disposed so as to be rotatable in an annular volume in the vicinity of said motor;
• and
• air flow blocking means to prevent at least some air from exiting said heat sink in a direction parallel to said fins, whereby air moved by said fan is made to flow beneath said motor and thence to exit from said gaps.