BaTiO/sub 3/ synthesis technique and its effect on BME dielectric formulations

Abstract

Within the worldwide capacitor industry there is a wide range of synthesis techniques for producing the starting BaTiO/sub 3/ precursor, which is the primary component for X7R capacitor formulations. The intention of this study was to draw some inherent conclusions about advantages or disadvantages of certain synthesis techniques. Several dielectric compositions for high capacitance BME multilayer ceramic capacitor (MLCC) applications have been examined. These formulations are based on BaTiO/sub 3/ precursors that were synthesized from solid state as well as two oxalate methods. The focus of this work was to identify the influence that the host BaTiO/sub 3/ had on the reliability of the MLCC. The model proposed by Prokopowitz and Vaskas was used to characterize the reliability behavior. Analysis of the data shows that it is very difficult to predict how a particular BaTiO/sub 3/ precursor will work in a given BME formulation without actually producing the formulation and performing the appropriate testing. For the solid state based formulation the value obtained for /spl eta/ was much higher than expected where the E/sub a/ was comparable to the values found in the literature. However, while the two oxalate based formulations behaved very differently from the solid state system, they behaved very similar to one another. For these systems, the /spl eta/ was in agreement with the values found in the literature but the E/sub a/ was much higher than expected.