High Performance, Compact Capacitors for Pulse Forming Networks

This project addresses the development of a solid state polymer multilayer capacitor composed of thousands of nano-thick dielectric layers and self healing aluminum electrodes. Unlike conventional self supported polymer capacitor films that have limited polymer chemistries and dielectric thickness, the proposed capacitor system makes use of a family of highly cross linked amorphous polymer dielectrics, that have dielectric constants in the range of ?=2.5-13, breakdown strength >1000V/?m and are integrated with aluminum electrodes into a capacitor using a non contact process, in an environment free of particulate contaminants. This results in defect free polymer dielectrics that have low dielectric absorption due to their amorphous character, and breakdown strength higher than any self supported film dielectric due to the combination of the intrinsic polymer properties and their submicron thickness. In the phase I work the main focus of the effort was to develop a “layer isolation process” in order to elevate the energy density of these polymer multilayer capacitors. The results show that single layer small area capacitors were produced with energy densities as high as 11.5J/cc, which is typical for submicron thick acrylate polymer dielectrics. Multilayer capacitors with 1200 capacitor layers that were “partially processed” for layer isolation, exhibited energy densities as high as 3.4J/cc. The Phase II work will be designed to complete and optimize the layer isolation process in order to further increase the capacitor energy density. Capacitors with different dielectric constants and dielectric thickness will be produced and will be tested for basic capacitor properties including energy dencity, dissipation factor and capacitance at different temperatures and dV/dt discharge characteristics.