Characterization and properties of an organic–inorganic dielectric nanocomposite for embedded decoupling capacitor applications

Polymer/aluminum nanocomposites have a high dielectric constant and a low dielectric loss because of the combined characteristics of polymer–ceramic (due to the insulating ceramic shell of an aluminum particle) and polymer–metal (due to the metal core of an aluminum particle) systems. In this work, an aluminum particle surface treatment was performed with an epoxide-functionalized silane coupling agent in order to further improve the dielectric properties and processibility of polymer/aluminum composites. Fourier transformed infrared spectroscopy (FTIR) and thermogravimetric analyzer (TGA) were used to characterize the aluminum particles before/after coupling agent treatment. It was found that the silane coupling agent was successfully grafted on the aluminum particle surface. Rheology studies of polymer/aluminum composites showed that the coupling agent treatment could significantly reduce the viscosity of the aluminum composites, which indicates coupling agent treatment can improve the processibility of aluminum composites at high filler loading levels. Dielectric properties, including the frequency responses and temperature coefficient of capacitance of the aluminum composites were studied with a dielectric analyzer (DEA). The microstructures of aluminum composites were characterized with a field emission scanning electron microscope (SEM). It was found that a coupling agent treatment can improve the aluminum particle distribution and thereby enhancing the dielectric constant of aluminum composites.