High Temperature Capacitors for Power Converters

High temperature capacitors based on a new family of ferroelectrics are proposed. The Curie temperatures of the (1-x)BiMeO3 - (x) PbTiO3 (Me = Sc, In, Yb, or Fe) family have been found to range from 450C to >600C. Multilayer ceramic capacitors based on these materials offer a distinct advance in the working temperature compared to currently available devices. The aim of this Phase I project is to fabricate prototype high temperature capacitors with capacitance values ranging from 10nF to 1microF at 300C using standard multilayer capacitor fabrication techniques. After initial studies determine the most desirable composition(s), prototype capacitors will be fabricated and tested. Electrical testing will primarily be focused on reliability issues including HALT testing, impedance spectroscopy, insulation resistance, and leakage mechanisms. Finally, the performance of the prototype capacitors will be compared to commercially available devices.