The fundamental differences between microwave siniering process and conventional sintering mathod for $BaTiO_3$ thick film have been studied from the present work. The similar sintering characteristics can be obtained for the bulk $BaTiO_3$ specimen by microwave sintering at the temperature of 180℃ lower than that of fast sintering. The trend of firing shrinkage, relative density, and grain size changes are similar to that of fast sintering process, however, the grain size variation was large in the fixed sintering temperature, sintering time, and heating rate, especially the grain size of microwave sintered samples are larger than those of conventional ones at the same densities. From the results of the dielectric characteristic measurement at 1 kHz at various temperatures, the loss tangent of the microwave sintered sample increased gradually and that of a fast sintered one showed maximum peak at the Curie temperature. The dielectric constants for both cases showed sharp peaks at Curie temperature, especially the height and slop of the peak tended to increase as the grain size decreased.
It can be summarized from the above results that the microwave sintering was accelerated by the non-temperature effect and the densification rate was comparable but the grain growth rate was faster when compared to that of fast sintering process.
