Raytheon Company

Hughes Aircraft Company

Manuel B Valle

Clark A Saito

Stuart J Marble

Robert S Hutchins

Kwang Yeh

Ronald E Hoover

A thermal shunt comprising flexible graphite fibers for removing heat from components coupled thereto and providing mechanical isolation. The thermal shunt comprises a plurality of stacked layers of graphite fibers secured together at opposite ends to form rigid sections at the respective opposite ends that provide for thermal coupling. Portions of the graphite fibers between the rigid sections are flexible and provide mechanical isolation between components to which the thermal shunt is coupled.

Flexible graphite fiber thermal shunt

A modified printed wiring board for reducing the cracking of solder joints used to attach ceramic leadless chip carriers to the surface of the printed wiring board. A relatively thin expansion layer is provided on top of the conventional printed wiring board. This expansion layer is bonded to the printed wiring board except at locations underneath the footprint of the chip carrier and solder joints. This expansion layer reduces the stress on solder joints between the ceramic leadless chip carrier and the printed wiring board due to thermal expansion mismatch, to thereby reduce cracking of the solder joint. Prevention of bonding underneath the chip carrier footprint is provided by a thin layer of polytetrafluoroethylene (PTFE). Methods for applying ther PTFE layer are disclosed.

Process for fabricating compliant layer board with selectively isolated

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Covina, CA, United States of America

Manuel B Valle