Planar integrated multilayer capacitive substrate for DC-DC converter applications

This exploratory work aims to develop and validate a technology of plane substrates close to "Busbar" but directly integrating capacitive layers. These capacitive layers may be used to realize the decoupling capacitor required by any switching cells on its DC bus and/or to realize the capacitors of a common filter placed on the same DC bus. As an additional property, this approach allows matching the shape and the arrangement of the capacitive layers with the building requirements of the full converter. The technological process to achieve that aim is the screen-printing technique. The process was optimized in order to manufacture high electrical performance multilayer ferroelectric ceramic capacitors. High capacitance values density (2, 2÷2, 7nF/mm²), low parasitic losses (ESR<;11MΩ ESL<; 3nH), low leakage currents, high dielectric withstand voltage (>300V) are obtained. These new integrated passive components are then used for the realization of planar integrated multilayer capacitive substrate in a practical DC-DC converter.