Influence of the crystallite size of BaTiO3 on the dielectric properties of polyester reactive resin composite materials
B. Schumacher, H. Geßwein, T. Hanemann, J. Haußelt
Forschungszentrum Karlsruhe, DE
composite, dielectric properties, crystallite size
Today’s electric equipment has to be small in dimension and rich in functionality to be successful with the customer. The available surface area on today’s printed circuit boards (PCB) is decreasing as a result and therefore it is a huge gain to integrate electric functionality into the layers of a PCB. Putting passive components into the PCB is one big step that can be taken to reduce the PCB surface area needed. To produce integrated capacitors a material with a high dielectric constant and a processing temperature of less than 200°C is needed. Polymer composites are developed to meet those needs. They can be processed like other reactive resins while showing enhanced dielectric properties. Commercially available bariumtitanate powders have been processed to composite materials using a polyester reactive resin as the polymeric matrix. The rheological and dielectric properties (at 100kHz-10MHz) of the composite materials where investigated. Large interest was taken into the influence of the crystallite size of the bariumtitanate powder on the dielectric properties of a composite material. Controlled crystallite growth of a nano powder has been initiated by thermal treatment. The crystallite size is largely influential and a huge optimization factor for high dielectric composite materials.
Nanotech 2008 Conference Program Abstract