Dielectric performance enhancement of nanoparticle-based materials for embedded passive applications

Novel materials for embedded capacitor applications are in great demands, for which high dielectric constant (k), low dielectric loss and process compatibility with the printed circuit boards (PCBs) are the most important prerequisites. We have systematically investigated an efficient way to enhance the dielectric performance of the high-k nanocomposites by the selection of the appropriate filler, its size, size distribution, surface property and morphology (aggregation status). The effect of the size and size distribution of metal nanoparticles in the nanocomposite on the dielectric properties of the nanocompsite were studied on an in-situ formed silver (Ag) incorporated carbon black (CB)/polymer composites system. In-situ formed Ag nanoparticles in the Ag/CB/epoxy composites increased the dielectric constant (k) value and decreased dissipation factor (Df). The size and size distribution of metal nanoparticles in the nanocomposite were found to have significant influence on the dielectric properties of the nanocomposite system. Smaller size and narrower size distribution of Ag nanoparticles resulted in lower dielectric loss tangent. The investigation of the morphology in terms of the aggregation status of nanoparticles on the dielectric properties of the nanocomposite revealed that assembly of the nanoparticles impact the dielectric performance of the nanocomposite in terms of the interfacial polarization and conducting property. The Ag/epoxy nanocomposite containing Ag nanoparticle with more discrete morphology rendered much lower dielectric loss tangent compared to the nanocomposites with Ag nanoparticles of more aggregated morphology.