Contents I. Introduction
Recently, vibration analysis of Multi-Layer Ceramic Capacitor (MLCC) becomes very important because it makes problems of electronic devices or in-vehicle electronic systems such as acoustic noise or malfunction. Thus, it is important to analyze and reduce the vibration of MLCC. It is caused by electro-mechanical properties of the dielectric layer which consists of . There are two main properties; piezoelectricity and electrostriction. is one of the most popular ceramic material which shows piezoelectricity. It is used to make dielectric layer because of its high permittivity. Although there is no poling treatment of MLCC, applied DC bias makes polarization of dielectric layers and increase the piezoelectric coefficient. Thus, when AC voltage applied to the MLCC, vibration occurs which is enough to excite circuit board where MLCCs are mounted. Meanwhile, electrostrictive vibration of MLCC also could not be negligible because of two reasons. First, strong electric field generated between inner electrodes makes large electrostrictive vibration which is similar with piezoelectric vibration level. Second, electrostriction makes second harmonic frequency vibration of applied AC voltage because it is nonlinear phenomenon as opposed to the piezoelectricity. Thus, both two vibration mechanism must be considered together in vibration analysis.
