A thermally-conductive, electrically insulative interface for conductively cooling a heat-generating source, such as an electronic component, having an associated thermal dissipation member such as a heat sink. The interface is provided as a cured sheet of a curable material formulated as a blend of a curable silicone binder, and a particulate alumina, i.e., aluminum oxide (Al2O3), filler. The interface is observed to exhibit a thermal conductivity of at least about 0.8 W/m-K and a wet dielectric breakdown strength of at least about 475 Vac/mil.