The impact of moisture absorption on the electrical characteristics of organic dielectric materials

Organic dielectric materials will absorb moisture when in direct contact with a liquid or a humid environment. The dielectric then becomes a two-phase dielectric composite with new dielectric characteristics. Using the Lichtenecker Equation, the composite dielectric permittivity and loss characteristics are modeled. The loss modeling includes the polymer dielectric loss characteristics, as well as the conductive loss of the moisture. The model is also used to predict the frequency dispersion of the relative permittivity at lower frequencies caused by the conductivity of the moisture. The modeling is validated using high frequency measurements of interdigital capacitors, which correspond to the modeling within 5% across the entire examined frequency range.