The effects of the additive size and the sintering conditions on the electrical properties, especially in regards to the reliability, of a X7R type multilayer ceramic capacitor (MLCC) possessing a Ni internal electrode and thin layers were investigated. Using planetary and attrition milling (SC mill), we crushed the additive while utilizing an optimized solid loading. We achieved an average particle size of 500 nm using the pass crushing method of the high energy planetary and attrition milling according to the power intensity. In our results, we found a decrease in the permittivity of the multilayer ceramic capacitor as the average particle size of the additive decreased. However, the highly accelerated life testing (HALT) was improved. The dielectric permittivity and the insulation resistance (IR) increased as the additive amount of the MgO and glass increased. However, as the Y2O3 rate increased, these properties showed a decreasing trend. As the sintering temperature increased, the characteristics of the dissipation factor, insulation resistance, and the break down voltage (BDV) increased. In the aspect of the sintering conditions at ambient H2, because a great quantity of H2 was applied to the samples, the capacitance, dissipation on factor, insulation resistance, and break down voltage decreased. However, the samples' highly accelerated life testing properties were improved

Keywords: MLCC, HALT, IR, BDV