METAL MATRIX COMPOSITE HEAT SINK WITH IMPROVED THERMAL TRANSMISSION

THERMAL MANAGEMENT IS ONE OF THE CRITICAL ASPECTS OF PACKAGING DESIGN WHICH ENSURES RELIABLE OPERATION OF ELECTRONIC COMPONENTS. LIFETIME AND PERFORMANCE OF THESE COMPONENTS CAN BE INCREASED DRAMATICALLY IF THE HEAT GENERATED IN THE CIRCUITS CAN BE EFFICIENTLY REMOVED BY HEATSINKS TO REDUCE JUNCTION TEMPERATURES AND MECHANICAL FAILURES CAUSED BY THERMAL STRESSES. METAL MATRIX COMPOSITES (MMC) CAN PROVIDE UNIQUE COMBINATIONS OF PROPERTIES THAT MAKE THEM OUTSTANDING CANDIDATES FOR PACKAGING APPLICATIONS, ESPECIALLY HEAT SINKS. WE PROPOSE TO DEVELOP MMC'S UTILIZING GRAPHITE FIBERS (P100 OR P120 FROM AMOCO) THAT WILL RESULT IN MMC'S WITH EXTREMELY HIGH THERMAL CONDUCTIVITIES (600W/MK) IN X AND Z DIRECTION, LOW COEFFICIENT OF THERMAL EXPANSION ( 4X10(-6)/DEGREES CENTIGRADE) IN BOTH X AND Y DIRECTION FOR DIMENSIONAL STABILITY AND LOW DENSITY OF 3.5G/CC. WE PROPOSE TO UTILIZE FIBER SPREADING INA DIVERGENT PNEUMATIC OR LIQUID FLOW FIELD, FOLLOWED BY UNIFORM DEPOSITION OF COPPER OR ALUMINUM ON THE SPREAD FIBERS BY HOLLOW CATHODE PLASMA TECHNIQUE. A THIN (0.01-0.1MU) INTERFACE LAYER OF SI OR MO WILL BE APPLIED, IFNECESSARY, TO IMPROVE ADHESION AND BETTER TRANSLATION OF MECHANICAL AND THERMAL PROPERTIES. THE COATED FIBERS WILL THEN BE WEAVED OR PLACED IN DESIRED ARCHITECTURE AND CONSOLIDATED AT 50 TO 80% OF MELTING TEMPERATURE. HIGH THERMAL CONDUCTIVITY HIGHLY PYROLYTIC ORIENTED GRAPHITE (HOPG) WILL BE INCLUDED TO ENHANCE HEAT TRANSFER IN Z DIRECTION. HIGH THERMAL CONDUCTIVITY MMC TECHNOLOGY DEVOLOPED IN THIS PROGRAM WILL BENEFIT A BROAD RANGE OF APPLICATIONS INCLUDINGFIRST WALL STRUCTURES IN FUSION REACTOR, ENGINE COMPONENTS IN TURBINE AND IC ENGINE, RADIATORS, DAMPENERS, AND OTHER HEAT TRANSFER APPLICATIONS.