Abstract: An efficient heat sink having a high density of fins and a large effective surface area is formed by coiling a flat strip of thermally conductive material in which teeth or millifins have been formed by a stamping operation, for example. A spacer may be employed to insure fin separation. In an alternate embodiment, the strips are stacked. The resulting heat sink is particularly effective in impingement flow cooling of electronic devices, chips, circuits or modules.

Abstract: A method and apparatus which provide field upgradability of an electrical system's air cooling capacity. In particular, air-moving devices are disposed in an external enclosure which is mated with a base unit in such a way as to convert one of the base unit's exhaust ports to an added inlet port. Accordingly, thermal upgradability in the field is easily provided by removing lower capacity interior blowers, by providing and using an access port into the middle of the old air flow path and by attaching an exterior unit having increased air moving capacity.

Abstract: A heat sink is provided for use with stacks of integrated circuit chips. The heat sink comprises a thermally conductive body having a recess in which the chip stack is disposed. The heat sink also includes fins which extend away from the recess. In one embodiment, fins are provided inside the recess for improved cooling of higher power chips such as a microprocessor which is surrounded by less thermally demanding memory chips.

Abstract: A convertible cooling module, especially for use in conjunction with a wide range of computer systems ranging from workstations to massively parallel processors is employable with both air and water cooling systems. In particular, a cooling module is convertible from a heat sink modality to an air cooling modality, and finally to a liquid cooling modality in response to either increased performance demands or an increase in the number of processors or circuit components employed. The conversion may be carried out in the field and provides a flexible and less costly upgradeability path for computer customers.

Abstract: A slash resistant composite material and surgical glove made of such material. The composite material comprises a polymeric matrix having embedded therein hard material whiskers which are oriented randomly in the matrix. The whiskers consist of a material selected from the group consisting of silicon carbide, carbon and mixtures thereof. The diameter of the whiskers ranges from 0.00015 to 0.0005 inches and the length of the whiskers ranges from 0.0625 to 0.125 inches.

Abstract: A thermally optimized piston for use in a liquid cooled module. The thermally optimized piston has three distinctive sections, an upper tapered section, a central cylindrical section, and a lower diverging section. In a preferred embodiment, the thermally optimized piston is provided as part of an improved electronic module. The improved electronic module includes enhanced convective cooling channels disposed between the pistons.

Abstract: A system and method of cooling which uses both jet impingement and conduction cooling. Conduction cooling is accomplished by placing a cluster of pistons in contact with each chip. The pistons have a rectangular foot at the bottom which contacts the chip. A dielectric coolant, such as liquid nitrogen or fluorocarbon is delivered at the center of each cluster, the fluid flows over the top of the feet, and in the channels between the feet, providing jet enhanced convective cooling at the lower portion of the pistons. Advantageously, the pistons serve as extended surfaces which increase the area over which the forced convection cooling occurs. In a preferred embodiment, microfins protruding from the header sections of each piston further increase the area for heat transfer. In addition, for non-boiling applications, grooves are added to the piston foot surface that contact the chip to insure wetting of the chip-piston interface.

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.