Mechanically floating multi-chip substrate

Abstract

A multi-chip module includes a mechanically floated substrate on which integrated circuit devices are mounted. The substrate is located within a heat exchanger. In one embodiment, a spring or an array of springs biases the substrate upwardly to press the integrated circuit devices against a surface within the heat exchanger. The substrate is displaceable with respect to the heat exchanger, allowing accommodations to differences in thermal expansion coefficients and to non-uniformities resulting from less than exact manufacturing tolerances of the substrate, the heat exchanger and the integrated circuit devices. Another embodiment includes resting the substrate on a conformable membrane that is used to entrap a fixed volume of thermally-conductive liquid. The membrane-and-liquid arrangement mechanically floats the substrate and ensures a proper integrated circuit device/exchanger thermal interface. A flexible multi-conductor interconnect is electrically coupled to the substrate to allow conduction of signals to and from the substrate without interfering with the ability of the substrate to float mechanically. Also disclosed is a module in which the membrane-and-liquid arrangement is used at the integrated circuit device side of the substrate to achieve a deformable electrical and thermal flow path from the integrated circuit devices to the heat exchanger. The membrane adapts to variations in the heights and/or angles of the integrated circuit devices.