A Study on Dielectric Constants of ${rm Epoxy/SrTiO}_{3}$ Composite for Embedded Capacitor Films (ECFs)

Online Available
Authors: Lee, S.; Hyun, J. -.; Kim, H.; Paik, K-W;
Publishing Info: Advanced Packaging, IEEE Transactions on [see also Components, Packaging and Manufacturing Technology, Part B: Advanced Packaging, IEEE Transactions on] , --(3), 428--433.
Year: 2007

Abstract: ${rm Epoxy/BaTiO}_{3}$ composites have been of great interest as embedded capacitor materials, mainly due to high dielectric constant of ceramic powders, and good process compatibility of epoxy with printed circuit boards (PCBs). However, one of the potential problems of ${rm epoxy/BaTiO}_{3}$ composite is the dielectric relaxation at gigahertz range. In this paper, ${rm epoxy/SrTiO}_{3}$ composite embedded capacitor films (ECFs) were fabricated for high-frequency applications. Dielectric constants of ${rm epoxy/SrTiO}_{3}$ composite embedded capacitor films with various ${rm SrTiO}_{3}$ particles loading for three different commercial ${rm SrTiO}_{3}$ powders were measured, and experimental data were fitted to the Lichtenecker equation for the prediction of the effective dielectric constant of ${rm SrTiO}_{3}$ powders in ${rm epoxy/SrTiO}_{3}$ composite ECFs. Using a rectangular cavity resonator method, dielectric constants of ${rm epoxy/SrTiO}_{3}$ composite ECFs were measured at gigahertz range (1–10 GHz). At gigahertz frequencies, dielectric constants of ${rm epoxy/SrTiO}_{3}$ composite ECFs were nearly constant. In contrast, ${rm epoxy/BaTiO}_{3}$ composite ECFs showed decrease of dielectric constants above 5 GHz. Therefore, it is concluded that ${rm epoxy/SrTiO}_{3}$ composite ECFs can be more effectively to be applied for hi- gh-frequency applications.

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