Failure analysis and improvement research on flexible termination multilayer ceramic capacitors

Flexible termination multilayer ceramic capacitors (FTMLCCs) denote a distinct class of capacitors that incorporate an additional resin-conductive filler layer into the terminal electrode of surface-mount capacitors, establishing a flexible electrode layer. This layer is designed to absorb thermal and mechanical stresses incurred during soldering, consequently reducing the risk of ceramic body cracking. By assimilating flexible termination technology into MLCCs, we can diminish failure risks associated with external stresses without expanding the capacitor's size or diminishing its capacitance. It is crucial to identify potential failure mechanisms when leveraging FTMLCCs for packaging or assembly operations. In this study, we dissect the termination structure, failure modes, and the efficacy of attempted improvements in two types of FTMLCCs. We scrutinized the interface structure of end-termination layers and the characteristic structure of the conductive-epoxy layer using advanced scanning electron microscopy (SEM) and 3D structure reconstruction via focused ion beam (FIB) techniques.