Future satellites require significant size and weight reduction. Further, thermal density increases as components are made smaller to increase functional performance and to save space and weight. Increased power density of advanced electronics requires new materials development to meet the challenges of thermal management. In addition, miniaturization of thermal control devices and components is essential for micro-spacecraft and micro-instruments. Chip-on-board (COB) technology provides for simplification of current electronic packaging hierarchy. Low-cost, C-SiC composites matching the coefficient of thermal expansion (CTE) of Si were developed for Si chip-based electronics, while low-cost C-C and metal matrix composites, matching the CTE of GaAs were developed for GaAs-based electronics. Novel dielectric insulation and metallization schemes were developed to facilitate this technology. This novel technology showed excellent performance in cyclic testing as well as excellent thermal dissipation at a power density up to 50 W/cm. Manufacturing and testing results of this novel technology are reported.