Gas Cooling Enhancement Technology for Integrated Circuit Chips

New approaches are described for increasing the capability of forced gas convection cooling for integrated circuit chips, using an enhanced heat transfer technique and a higher gas flow velocity in a closed-cycle flow. A turbulence promoting fin with low pressure loss has been developed and enhancement of the heat transfer coefficient using gas flow velocities up to 50 m/s is examined using air and helium gas as coolants. ´By applying these techniques, the cooling capability of a package is investigated through the use of prototype equipment. Cooling of an alumina substrate (75 mm square) mounted with 25 chips (8 mm square) can be cooled up to 200 W in an air flow of 20 m/s. In helium gas convection cooling, the allowable heat dissipation increases to 300 W or more, and fan input power decreases to about one-fifth of that needed for air convection cooling. This cooling capability is equal to that of indirect water cooling.