Physical and electrical properties of ink-jet and screen printed patterns for RFID HF antennas

The physical and electrical characterizations and modeling of several patterns printed by ink-jet and screen printing are presented in this work. The main goal was to determine suitable techniques to manufacture RFID antennas by using different conductive Ag inks, pastes and substrates commonly used in RFID. The physical characterization consisted of measurements of the layer thickness and Root Mean Square roughness of the patterns. An analytical model has been used to predict the thickness of the ink-jet printed pattern based on the printing conditions and the chemical composition of the conductive ink. DC electrical characterization has been carried out to study different conductive inks and substrates, and the lowest sheet resistance has been identified four every analyzed case. Finally, inductors have been fabricated by ink-jet printing using the optimal conditions obtained from this work, Sun Tronic U5603 Ag ink and Polyetherimide substrate to validate the present study.