Thermal, electrical, and mechanical properties of layered substrates for microelectronic applications

Abstract

In the present work, a new approach was introduced to fabricate high thermal conductive substrates for microelectronic applications. A layered system configuration was employed. Carbon fibers, laid in the form of a mesh, were sandwiched between the alumina layers to serve as an interlayer. Different thickness alumina tapes were prepared to form the layered systems to investigate the effect of carbon fiber/alumina thickness ratio on materials thermal, electrical, and mechanical properties. It was noted that the incorporation of carbon fiber in alumina could enhance the thermal conductivity and reduce the dielectric constant of the substrate. However, the degradation of the electrical resistance was found as the amount of carbon fiber increased in the layered systems. The mechanical properties of the prepared materials were sound, and the alumina fracture toughness in some areas near the carbon fiber was enhanced due to the diffused carbon. It was suggested that the substrate with the thickness ratio of 0.037, which provided 60% enhancement of thermal conductivity, 40% reduction of dielectric constant, but a reduction of 30% in electrical insulation compared with blank alumina, appeared to be a good configuration for microelectronic applications.