3-dimensional FEM simulations of resonances in the impedance characteristic of ceramic multilayer capacitors

Resonances in the impedance spectra of Ceramic (M) under bar ultilayer (C) under bar apacitors (MLCs) with X7R dielectric are calculated and compared with measured resonance spectra. The simulations have been performed with t he Finite Element Method applied to a 3-dimensional model of a capacitor. T he model is verified with spectra of faultless size 1210 and 1812 capacitor s. Investigations on the influence of an introduced crack in the longitudin al direction of a type 1210 MLC work out a good agreement between simulatio ns and measurements. These results can be used as input data for a non-dest ructive failure test based on impedance spectroscopy.