Theoretical (Ideal) Module Cooling and Module Cooling Effectiveness

When contemplating processor module cooling, the notion of maximum cooling capability is not simple or straight forward to estimate. There are a multitude of variables and constraints to consider; some more rigid or fixed than others. This paper proposes a theoretical maximum cooling capability predicated on the treatment of the module heat sink or cold plate as a heat exchanger with infinite conductive and convective behavior. The resulting theoretical minimum heat sink thermal resistance is a function of the bulk thermal transport of the fluid dependent only on the fluid’s density, specific heat (at constant pressure) and volumetric flow rate. An ideal module internal thermal resistance will also be defined. The sum of the two resistances constitutes the theoretical minimum total module thermal resistance and defines the ideal thermal performance of the module. Finally, a module cooling effectiveness relating the actual module thermal performance to the ideal thermal performance will defined. Examples of both air and water cooled modules will be given with discussion on the relevance and utility of this methodology.© 2015 ASME