Laser Printing of RFID Antenna Coils on Ceramic

Abstract

Printed electronics are a major field of activity in research and industrial applications nowadays, especially in thick-film technology. Within the last decade, large progress was made to digitally print electronic circuits, in order to supplement or replace the established screen printing technology. The advantage of digital printing is its capability to rapidly produce any layout desired at minimum space requirements. This highly flexible production method is especially applicable for prototyping and small series productions. Electrophotography, commonly known as laser printing, has been considered very rarely as a method for digital printing of electronic circuits. It is a completely solvent-free method with high speeds and a high potential regarding precision. At Helmut Schmidt University, electrophotography is tried to be established as an alternative method to print silver lines as basis for a conductive layout. After a first set of conductive silver lines was printed and the results were published, this paper describes the development from initial conductivity to a functional circuit element. Deficits in toner transfer to tape are examined and a more effective transfer method is established. Furthermore, the performance of the used silver toner is improved, and the best toner for the desired application is determined. Silver lines are printed on green tape and sintered in a co-firing process, as well as on ceramic using a post-firing process. After reaching a certain level of quality, a functional RFID antenna coil is printed that proves the capability of the process to create a conductive layout.