A method for predicting the dielectric strength of batch MLCCs based on grain structural parameters

Multilayer ceramic dielectric capacitor (MLCC) is widely used in circuits, and the dispersion of the ceramic dielectric performance is the main reason for breakdown. In manufacturing, the MLCC quality level is determined by a dielectric breakdown test of some samples taken from a batch. A few studies have built numerical analysis models to calculate the grain size effect on dielectric breakdown, which is more suitable for the specific samples. To face these challenges, this paper establishes a method for predicting the dielectric strength of batch MLCC based on grain structural parameters. This method represents the process influencing the finished dielectric in MLCC by distributing grain size and defects. Then, a graphic model was built to analyze the rule between the dielectric structure and the MLCC dielectric strength. A batch of MLCC was selected as an example, and photographs of dielectric were measured using the watershed algorithm to obtain the distribution of grain sizes and defects, which were used to quickly predict their dielectric strength. Finally, a breakdown test was applied to this batch to verify the validity and accuracy of this method of predicting results.