Experimental thermal conductivity and contact conductance of graphite composites

Abstract

Graphite fiber organic matrix composites were reviewed ics. for potential heat sink applications in the electronics packaging determined the effective transverse and longitudinal thermal industry. This experimental investigation conductivity and contact conductance of composites consisting of high thermal conductivity graphite fibers in a cyanate ester matrix. Three different fiber types of fibers (DICE X, DKA X and 1122X%) with three different fiber volume percentages (55%, 65%, and 75%) were used. The effective thermal conductivity was determined in the transverse direction over temperature range of 20 OC to 200 OC and at an interface pressure of 2068 kPa (300 psi), while the longitudinal direction effective thermal conductivity value was determined over the same temperature range and a pressure of 1380 kPa (200 psi). Furthermore, the thermal contact conductance was determined at a mean interface temperature of 20 OC and 60 OC and at apparent interface pressures ranging from 172 kPa (25 psi) to 1723 kPa (250 psi). The thermal conductivity varied little with temperature and appears more dependent on the thermal conductivity of the fibers and fiber volume fraction. The conductance value appeared to increase slightly with increased pressure.