Journal of Applied Polymer Science, Vol.80, No.12, 2328-2334, 2001
Three-dimensional dielectric characterization of polymer films
Polymer films are widely used in electronic packaging applications due to their low dielectric constant and ease of fabrication. These films often exhibit anisotropic electrical and thermomechanical properties, due to orientation of polymer chains, which need to be evaluated for performance and reliability modeling of electronic packages. This article presents a dual-capacitor technique to measure the anisotropic dielectric permittivities of such films. Results are reported for in situ measurements for several spin-coated polymeric films, some of which exhibit different permittivities in the in-plane (x and y) and the through-plane (z) directions (transversely isotropic), and free-standing liquid crystalline Vectran films which exhibit orthotropic permittivities.
Keywords:dielectric permittivity;anisotropy;dual-capacitor technique;liquid crystalline polymer;polyimide;benzocyclobutene;polynorbornene