Pore evolution and microstructure with heating profile in BaTiO 3-based Ni-MLCCs with Y5V specification

Abstract

The effects of the heating profile in the burnout and sintering processes, especially the heating rate and holding time, on the pore evolution and microstructure in multilayer ceramic capacitors (MLCCs) showing Y5V characteristics, were investigated in order to optimize the fabrication process. The heating rate was controlled as 1, 3, and 5 °C/min in both burnout and sintering processes or the sintering process was carried out with and without the holding time of 3 h at the final sintering temperature of 1200 °C. The pore size distribution and cumulative pore surface area became broad and small, respectively, as the heating rate and sintering temperature were increased. The microstructure revealed that the MLCCs were effectively densified in the slow heating rate of 1 °C/min in both processes with the holding time of 3 h. The heating rate in the burnout process predominantly affected the pore evolution and microstructure more so than that in the sintering process, showing the effects of the holding time on removing the residual pores and on developing the final microstructure.