Prognostics of Failures in Embedded Planar Capacitors using Model-Based and Data-Driven Approaches

This paper presents the application of model-based and data-driven approaches for prognostics of failures in embedded planar capacitors. An embedded planar capacitor is a thin laminate that serves both as a power/ground plane and as a parallel plate capacitor in a multilayered printed wiring board. These capacitors have gained importance with an increase in the operating frequency and a decrease in the supply voltage in electronic circuits since they can enable miniaturization of electronic circuits as well as improved electrical performance. In next generation electronic circuits, embedded planar capacitors will be crucial in communication, automotive, military, medical, and space applications. The capacitor laminate used in this study consisted of an epoxy-barium titanate nanocomposite dielectric sandwiched between Cu layers. Three electrical parameters, capacitance, dissipation factor, and insulation resistance, were monitored in situ during testing under elevated temperature and voltage-aging conditions. The failure modes observed were a sharp drop in insulation resistance and a gradual decrease in capacitance. An approach to model the time-to-failure associated with these failure modes is presented in this paper. Further, a data-driven technique known as the Mahalanobis distance method is also investigated for early detection of these failures.