Thermally conductive and electrically insulative material

A monolithic substrate including a silica material fused to bulk copper is provided for coupling with electronic components, along with methods for making the same. The method includes arranging a base mixture in a die mold. The base mixture includes a bottom portion with copper micron powder and an upper portion with copper nanoparticles. The method includes arranging a secondary mixture on the upper portion of the base mixture. The secondary mixture includes a bottom portion with silica-coated copper nanoparticles and an upper portion with silica nanoparticles. The method includes heating and compressing the base mixture and the secondary mixture in the die mold at a temperature, pressure, and time sufficient to sinter and fuse the base mixture with the secondary mixture to form a monolithic substrate. The resulting monolithic substrate defines a first major surface providing thermal conductivity, and a second major surface providing an electrically resistive surface.