THE INFLUENCE OF CHANNEL WIDTH ON NATURAL-CONVECTION AND BOILING HEAT-TRANSFER FROM SIMULATED MICROELECTRONIC COMPONENTS

The thermal behavior of three vertical inline heaters placed in narrow channels and cooled by one of two dielectric fluids (FC-72 or Galden HT-55) was experimentally studied. The influence of the channel width on natural convection and boiling heat transfer is discussed. The expe riments were carried out at saturation or under subcooled conditions, and the channel widths investigated were 33 mm, 2 mm, and 0.5 mm. The reduction of channel width decreases the heat transfer coefficient for natural convection, but it causes an increase in heat transfer perfor mance for nucleate boiling. In particular, for the boiling data taken in saturation conditions, the better thermal behavior was noted for th e 0.5-mm channel width; whereas, in the case of a subcooling of 10 K, the better thermal behavior was noted for the 33-mm channel width. In the latter test condition, on the heat transfer surface, nucleate boil ing and natural convection probably occur at the same time. The data o btained are useful for the design of compact microelectronic packages. (C) Elsevier Science Inc., 1997.