Book excerpt: Composite materials are traditionally designed for the mechanical properties, due to their structural applications. However, composite materials are increasingly used in non-structural applications, such as electronic packaging and thermal management. Moreover, structual composite materials that are multifunctional are increasingly needed, due to the demand of smart structures and the importance of weight saving. As a consequence, structural materials that can provide electronic functions are needed. Thus, electronic functions are desirable for boht non-structural and structural composite materials.