A facile preparation of temperature-stable borate ultra-low permittivity microwave ceramics for LTCC applications

An ultra-low permittivity Li2O-added CuO-ZnO-B2O3 multiphase ceramic was fabricated by means of sintering technique, and the phase compositions, microstructures and dielectric properties were investigated. Specimens can be sintered below 800 degrees C. All the sintered samples consist of Zn(BO2)(2) and CuB2O4. The variations in the microstructure and dielectric properties of borate ceramics samples were relied on the sintering temperature. The ceramic sintered at 785 degrees C for 2 h exhibits excellent dielectric properties of epsilon(r) = 2.86, Q x f = 38093 GHz (similar to 16.0 GHz), tau(f) = -2.17 ppm/degrees C, which indicates that the ceramic is a promising candidate for LTCC applications.