Abstract 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.
A processing component comprising, an enclosure (12) adapted to hold a dielectric liquid coolant (20), a plurality of circuit modules (14) which each have a planar array of one or more heat producing circuit devices, a heat conducting hat spaced orthogonally from the array, and means in the module for transferring heat from the array to the hat, the array defining a plane designated X-Y and the direction from the array to the hat being designated Z, means for supporting said modules in said enclosure, and means defining a path (25, 26, 27) for circulating the coolant past the circuit modules in a predetermined direction designated X, wherein the improvement comprises, a plurality of fins (30, 52) which extend from the hat in the Z direction and define channels (54) between the fins extending generally in the X direction, whereby the coolant increases in temperature in the upstream to downstream direction along the channels, said fins being substantially equal in thickness and equal in spacing in the Y dimension, a shroud (53) which is arranged over the fins to confine the coolant to the channels, said fins being tapered in the Z dimension in the upstream to downstream direction to decrease the cross sectional area of said channels linearly in the upstream to downstream direction to thereby increase the coolant velocity in said channels and compensate for the increase in temperature of the coolant between the upstream edge and the downstream edge of the circuit module.
Claim 2
Dependent Claim
246 words
A processing component comprising, an enclosure (12) adapted to hold a dielectric liquid coolant (20), a plurality of circuit modules (14) which each have a planar array of one or more heat producing circuit devices, a heat conducting hat spaced orthogonally from the array, and means in the module for transferring heat from the array to the hat, the array defining a plane designated X-Y and the direction from the array to the hat being designated Z, means for supporting said modules in said enclosure, and means defining a path (25, 26, 27) for circulating the coolant past the circuit modules in a predetermined direction designated X, wherein the improvement comprises, a plurality of fins (30, 52) which extend from the hat in the Z direction and define channels (54) between the fins extending generally in the X direction, whereby the coolant increases in temperature in the upstream to downstream direction along the channels, said fins being substantially equal in thickness and equal in spacing in the Y dimension, a shroud (53) which is arranged over the fins to confine the coolant to the channels, said fins being tapered in the Z dimension in the upstream to downstream direction to decrease the cross sectional area of said channels linearly in the upstream to downstream direction to thereby increase the coolant velocity in said channels and compensate for the increase in temperature of the coolant between the upstream edge and the downstream edge of the circuit module.