Ni particle surface descriptor to enhance roughness of Ni internal electrode in MLCCs

Abstract

The uniform and continuous nickel internal electrode is crucial in high capacity and highly reliable multi-layer ceramic capacitors (MLCCs). However, the mechanism and the key factors that affect the roughness of the electrode have not been investigated thoroughly. Thus, seeking suitable descriptors that describe the most influential element which decides the roughness is required for the logical design of the Ni paste. In this study, we analyzed the surface of nickel powders and compared their electrode roughness in the aspects of the surface carbon species on nickel nanoparticles. As the increase in the relative C–O/C–C and C=O/C–C ratios, the relative electrode roughness of C-Ni-1, C-Ni-2, C-Ni-3, and C-Ni-4 increased from 1.00, 1.29, 1.54 to 2.51. Thus, low contents of C–O and C=O on the surface of Ni particles could improve the uniformity of the electrode. This study suggests a valuable perspective to reveal the decisive component to build the optimum surface of nickel nanoparticles for uniform internal electrodes in MLCCs.