Direct heat pipe cooling of semiconductor devices

A heat pipe system has been used to reduce by as much as 33% the thermal resistance from junction to case in a semiconductor. Difficulties in utilizing heat pipes to cool transistor junctions include the physical problem of applying a wick to bring the working fluid in contact with the junction, the chemical problem of fluid-transistor material interactions, and the electrical interference that may be caused by the heat pipe. Development of fiber wicks and high-performance powder wicks for RF power transistors is given particular consideration.