A circuitized substrate in which three conductive layers (e.g., electroplated copper foil) are bonded (e.g., laminated) to two dielectric layers. Each of the foil surfaces which physically bond to a respective dielectric layer are smooth (e.g., preferably by chemical processing) and may include a thin, organic layer thereon. One of the conductive layers may function as a ground or voltage (power) plane while the other two may function as signal planes with a plurality of individual signal lines as part thereof. An electrical assembly and an information handling system utilizing such a circuitized substrate are also provided, as is a method of making the substrate.