Lacquered polymer-ceramic composite dielectric film for capacitors

The possibility of increasing the dielectric constant of lacquered thin film for capacitors was studied using a polymer-ceramic composite film consisting of polyphenylene oxide (PPO) polymer and TiO₂ fine particle filler Basic electrical characteristics of the composite film were investigated with a simple capacitor composed of aluminum foil lacquered with a composite dielectric layer 0.9 μm in thickness. Stacked capacitors were produced using double-metallized polyethylene terephthalate film on which the lacquered composite dielectric layer was formed. By an incorporation of 20 vol.% TiO₂ into the PPO matrix, capacitor volume was reduced by 30%. However, the capacitor showed a decrease of insulation resistance during the self-healing process. Similar results were obtained when TiO₂ was replaced with BaTiO₃