Low loss, low temperature cofired ceramics with higher dielectric constants for multichip modules (MCM)

This paper describes the development of new Low Temperature Cofired Ceramic materials (LTCC) with higher dielectric constants (epsilon(r)). These glass-ceramic materials have epsilon(r) in the range of 17 to 85 and demonstrate very low dielectric losses (tan delta) at radio and microwave frequencies, with thermal expansion coefficient (CTE) matched to that of GaAs. Dielectric properties were studied in a frequency range of 1 kHz to 10 GHz, and results are presented along with the effects of material crystalline structure. The new family of materials can address the growing demand of electronic manufacturers to reduce package size, minimize energy losses. and eliminate stray electromagnetic radiation. Materials can be used for IC packaging, discrete components, in radar, antennas systems, cellular phones, and for development of new devices with optimized parameters in VHF and UHF.