A multi-phase research and development effort has been conducted to explore improved cooling techniques for the FASTBUS system The research was supported by the Fermi National Accelerator Laboratory Some of the relevant, major requirements and limits of this system are: 1 The cooling system should not significantly interfere with the rapid handling of the cards; 2 The die temperatures of the integrated circuits should not exceed 85/sup 0/C; 3 The temperature differential between the dies of emitter coupled logic (ECL) circuits that connect directly to each other should not exceed 30/sup 0/C; 4 The temperature differential of the cooling air between any two points in the module should not exceed 20/sup 0/C; 5 In air cooled modules, the air temperature should not exceed 60/sup 0/C anywhere; and 6 The noise emanating from the computer should be at a tolerable level The first requirement, together with some related considerations, virtually excludes any direct liquid cooling schemes Thus heat removal from the chips themselves can be achieved either by convection to air or by a heat conducting structure which transfers the heat to the coolant used The second through fourth requirements are generally rigorous However, the fifth is for plastic encased microchipsmore » (CA3083 16-pin, high current transistor, dual in-line package) and can be relaxed for other types with lower internal thermal resistances Our work can be divided into three parts The first dealt with the development of an air cooled system based on the state-of-the-art of commercially available technology The second explored various air cooling techniques and the third, examined methods where the heat from the chips was conducted to water cooled plates located parallel to the chip carrying cards« less

Eric L. Gollihert

Papers

Advanced Cooling Technigues for FASTBUS Electronics