Effects of moisture absorption on the electrical parameters of embedded capacitors with epoxy-BaTiO_3 nanocomposite dielectric

摘要

In this work the effects of moisture absorption on the electrical parameters of embedded capacitors is investigated. Capacitors of two different areas embedded inside a four-layered printed wiring board were selected for this work. The dielectric was a nanocomposite of epoxy and BaTiO_3 which is common dielectric material used in embedded capacitors. These capacitors were exposed to elevated temperature and humidity conditions (85 ℃ and 85% RH) and two parameters, capacitance and dissipation factor, were measured in situ. The diffusion of moisture in the dielectric was also modeled using the finite element method (FEM), and the changes in electrical parameters were calculated theoretically. The FEM methodology was then verified by applying it on capacitors of different dimensions.