Unusual local electric field concentration in multilayer ceramic capacitors

Local electric-field around multitype pores (dielectric pore, interface pore, electrode pore) in multilayer ceramic capacitors (MLCCs) was investigated using Kelvin probe force microscopy combined with the finite element simulation to understand the effect of pores on the electric reliability of MLCCs. Electric -field is found to be concentrated significantly in the vicinity of these pores and the strength of the local electric-field is 1.5-5.0 times of the nominal strength. Unexpectedly, the concentration degree of the pores in the inner electrode is much higher than that in the dielectrics and dielectric-electrode interfaces. Meanwhile, geometry orientations are found to have a remarkable influence on the local electric field strength. The pores act as an insulation degradation precursor via local electric, thermal center, and oxygen vacancies accumulation center. Such unusual local electric field concentration of multitype pores can provide new insights into the understanding of insulation degradation evolution, processing tailoring and design optimization for MLCCs.(c) 2022 The Authors. Published by Elsevier B.V. on behalf of The Chinese Ceramic Society. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

The local electric-field around multitype pores in multilayer ceramic capacitors was investigated through Kelvin probe force microscopy combined with finite element simulation. The study found that the electric-field is significantly concentrated near these pores, with a strength 1.5-5.0 times higher than the nominal strength. Surprisingly, the concentration of pores in the inner electrode is much higher than in the dielectrics and dielectric-electrode interfaces. Geometry orientations were also found to have a remarkable influence on the local electric field strength. These pores act as precursors for insulation degradation through local electric, thermal, and oxygen vacancy accumulation centers.