A DIELECTRIC SURFACE COATING TECHNIQUE TO ENHANCE BOILING HEAT-TRANSFER FROM HIGH-POWER MICROELECTRONICS

Two benign methods of generating surface microstructures, ''spraying'' and ''painting,'' provide pool boiling heat transfer enhancement, The methods do not require the target surface to be exposed to high stress enviromnents, making them applicable to electronic component surfaces, The painted surface micro structures are applied to a rectangular, horizontally oriented surface, and provide np to a 85% reduction in incipient superheat, between a 70 and 80% reduction in nucleate boiling superheats, and as much as a 100% increase in the maximum heat flux (critical heat flux-CHF), beyond that of the nontreated reference surface, The surface micro-structures are also applied to a silicon test chip and tested at saturated and sub-cooled (45 degrees C) conditions using FC-72. At sub-cooled conditions, heat dissipation rates of 100 W/cm(2) were provided at junction temperatures of 85 degrees C, and the highest CHF observed was 159 W/cm(2), 224% higher than that from the untreated chip surface at saturated conditions.