Cofiring characteristics and dielectric properties for dielectric composites with macroscopic inhomogeneity and X7R characteristics

A multilayer dielectric composite with a compositional gradient and temperature-stable characteristic was successfully prepared through the conventional tape casting technique. The cofiring behaviors and dielectric properties of the composite were investigated. It was shown that processing parameters not only affected the physical integrity of the composites, but also altered their final dielectric properties. The processing sensitivity was attributed to the interfacial interdiffusion and mismatched sintering shrinkage. Microstructural observation and compositional analysis indicated that the sintered dielectric composite had macroscopic inhomogeneity and layer-like structure. By suitable structural and processing designs, the X7R EIA specification of the composite was obtained, together with low-sintering temperature and high dielectric constant.