Tim Mach1,Joachim Binder1
Karlsruhe Institute of Technology1
Tim Mach1,Joachim Binder1
Karlsruhe Institute of Technology1
Printed electronics are gaining more attention due to their ability to produce electrical components. For wireless communication, the high-frequency range plays an important role, which makes flexible components such as varactors interesting. Here, the ceramic or polymer dielectric is responsible for the dielectric properties. However, as both come with their own drawbacks, ceramic-polymer composites can be used to combine the excellent dielectric characteristics of ceramics and the easy processibility and flexibility of polymers. Furthermore, to obtain flexible varactors, inkjet printing offers a well-established method for the preparation in a fast and precise manner.<br/>In previous works, an inkjet printed capacitor system consisting of (Ba,Sr)TiO3)/PMMA has already been successfully implemented. However, for varactors, tunability can be achieved in a BST/P(VDF-TrFE) system with the introduction of ferroelectric PVDF based polymers. Herein, printable inks were developed with varying ratio between BST and P(VDF-TrFE) to achieve high tunability and low dielectric losses. Through rheological property and drying temperature adjustments, the so-called coffee stain effect can be prevented. Therefore, thin layers can be realized and characterized on their dielectric properties.