The enhanced cooling of IC chip arrays on printed circuit boards

The dissipation of heat generated is a key limiting factor to further miniaturization of electronic circuits. Forced convection cooling of these circuits is an economical and efficient technique used in many applications such as in micro, mini and mainframe computers. Enhancement of heat transfer can be achieved using barriers placed over the modules. These barriers act as turbulence promoters and hence enhance the heat transfer, but at the cost of a pressure drop across the barriers. Computations are performed for steady 2D laminar airflow over modules with constant heat flux conditions. The effects on heat dissipation and pressure drop by inserting inverted barriers in various configurations are studied. The inverted barrier is found to be an effective enhancement device, disturbing the flow, promoting thermal mixing and thus resulting in higher heat dissipation rates. The computations provide useful information on the effectiveness of barriers in enhancing the cooling of the chip arrays on printed circuit boards. Higher powered chips should be positioned near the entry region, and the barriers placed above the leading edge of the modules to achieve maximum heat transfer