On the accommodation of coolant flow paths in high density packaging

An analytical study was conducted to determine a balance between the switching speed of logic gates and the average wiring distance in the system on the basis of the heat removal capability of the coolant. One of the models consists of a row of gate-carrying cards flanked by side boards having networks to complete three-dimensional wiring. The gates are cooled by forced convection of FC-77 or water. It is shown that the wiring distance is seriously increased by the need to make room for coolant channels within the system. As a model of a single-card system, a square array of logic gates cooled by impinging liquid jets is considered. It is concluded that the space requirement of coolant flows could set the upper bound for the density of logic gate packing. It is pointed out that more heat transfer data are needed to complete a tradeoff study