Minimization of field enhancement in multilayer capacitors

Evidence has shown that capacitor failure can often be attributed to field enhancement that occurs near electrode tips. In this research, methods to minimize field enhancement have been investigated using a combination of finite element analysis and an evolutionary algorithm. Specifically, the two methods considered are (1) to modify the electrode structure and (2) to adjust the resistivity in the dielectric region surrounding the tip. Optimal electrode structures and resistivity profiles have been derived that result in a significant reduction of field enhancement. Interestingly, it is predicted that adjustment of resistivity can yield a much greater reduction with a relatively minor increase in conduction loss.