Cofired monolithic ceramic circuits

The process sequence and selected processes from the sequence that are used to manufacture cofired monolithic ceramic (CMC) circuits are discussed from developmental and process capability standpoints. Materials selected for use in CMC circuits must exhibit low dielectric constants, high thermal conductivity, and compatibility with high-speed semiconductor device packages. Alumina, which is a good compromise of all desirable material characteristics and whose cost is less than $0.10/circuit, is selected as the starting dielectric material. Other CMC circuit materials that increase performance and reduce cost include conductive materials such as the refractory metals, i.e., tungsten and molybdenum. It is shown that CMC circuits offer an attractive cost-effective alternative to multilayer thick film circuits.