"Micro Cooling Fan" flow from the "base" hidden level "blades" into and filled in the "outlet" of the cavity, when accumulated to a certain extent it will exceed the normal atmospheric pressure chamber in vitro - thus forming "wind. "The "Micro Cooling Fan" narrow front end backend generous "cavity" will force the internal airflow towards the rear end of a broader movement of the cavity, constantly "mutual squeeze" the air last only from a small slit (ie, "the downwind ") in the" leak "out. After continuous operation for some time, this "Micro Cooling Fan" structure can gradually strengthen air pressure, resorted to vent air gap faster flow.