Immersion cooled circuit module with improved fins

摘要

A circuit module that contains a planar array of chips has an improved fin assembly that transfers heat to a liquid coolant that is circulated through the fins in a single pass so that there is a tendency for the upstream edge of the fins to run cold and the downstream edge to run hot. The module can be immersed in the coolant. A shroud on the fins confines the coolant flow to channels defined by the fins, the shroud, and the base of the fins. The fin assembly is constructed so that the coolant channels are narrowed as a function of the temperature of the liquid coolant. The narrowing channels increase the coolant velocity and thereby improves the heat transfer at what would otherwise become the hot end of the module. The coolant velocity is increased at the appropriate rate to maintain equal cooling along the direction of coolant flow. The narrowing channels can be combined with other techniques for improving heat transfer, and in one embodiment the fin assembly has sets of fins spaced that increase in density along the direction of coolant flow. The increased fin density constricts the channels and thereby increases the coolant velocity. Modules with this fin assembly can be stacked closely together in an enclosure for a processing component. The processing component can hold other heat producing circuit devices either downstream of the finned modules or in a parallel coolant path.