Heat dissipation device having thermally conductive cover board

A heat dissipation device comprising:

• a casing forming a receptacle, the casing comprising upper and lower plates spaced from each other to define a chamber therebetween, first and second air entrances formed in said casing in fluid communication with the chamber, a first section extending from the casing and adapted to physically engage a heat source, and a second section extending from the casing and defining an interior space;
• an airflow generator received and retained in the receptacle of the casing;
• a heat dissipation module received in the interior space of the second section and comprising spaced fins that define at least one channel extending from the chamber to an air outlet, whereby an airflow induced by the airflow generator is driven through the channel for primary heat exchange with the heat dissipation device, wherein said first air entrance is formed in at least one of said upper and lower plates, and wherein said secone air entrance is defined in a side wall of said casing between said upper and lower plwtes thereof, the air flow incoming to said chamber through said second air entrance being in crossing relationship with said at least one channel of said heat dissipation module;
• and
• a surface cover board mounted to the casing and covering at least partially said first air entrance, the surface cover board being made of thermally conductive materials and defining air passages to allow air to flow therethrough for secondary heat exchange with the heat dissipation device.