High Temperature Superconductors (HTS) materials are ideal for many electrical applications. These applications include high speed interconnects, microwave structures and transmission lines, as well as electronic devices that utilize the unique electrical and magnetic properties of these materials. To date, the use of high temperature superconductors has been limited to a narrow range of substrate materials, due to the reactive nature of these superconductors. Chemical reactions between the substrate and the superconductor cause decomposition of the superconductor into an insulator. The researcher has developed a thick film system that allows the production of high quality HTS films on reactive substrates, such as alumina (Al203). This system utilizes a thick film buffer layer of pure silver in combination with thick film superconductors composed of Y1Ba2~CU30X. The silver buffer layer is designed to prevent contact between the substrate and the superconductor, thereby eliminating chemical reactions between the two materials. The development as well as the comprehensive characterization of these films is described in this work. / Master of Science