Investigation of dielectric properties of polymer laminates with polyvinylidene fluoride

The breakdown field strength of polymer laminates consisting of polymer base films coated with a thin layer of polyvinylidene fluoride (PVDF) was investigated. The spin coating technique was used to make a layer of PVDF film. It was found that the dc breakdown field strength could be increased by as much as 18% by applying a very thin coating. The breakdown field strength was insensitive to the thickness of the polymer base films and the thickness of the PVDF coating within the thickness range used in the experiment. The effect of the coating on the permittivity and dissipation factor of polymer films over a wide frequency range was determined. Possible mechanisms for the enhancement of breakdown field strength have been discussed.