Mechanism of Relaxor and Design of MLCCs in Next Generation

Abstract

Relaxor ferroelectrics are used as dielectrics in Y5V MLCCs and the shell of X7R MLCCs. The relaxor behavior affects the properties of MLCCs. In this presentation, the mechanism of diffuse phase transition in relaxors is reviewed as introduction. Properties of X7R MLCCs with different dielectric grain sizes were measured analyzed using spline and least-squares analyses to evaluate the properties of MLCCs with dielectric grains less than 100 nm. The results showed a thickness limit of dielectric layers exists for the improvement of the capacitance density. Domain effects on the dielectric properties and the possibility to use lead-free relaxors in the core of X7R MLCCs are discussed as a design concept of the future MLCCs.