RF performance of inkjet and stencil printed traces for flexible electronics applications

Interest in body area networks (BAN) operating in the millimeter-wave regime (60 GHz) is increasing due to concerns over the security of data transfer. Obtaining low loss in the higher frequencies is important for high performance interconnects. In this paper, two materials deposition techniques — inkjet printing and stencil printing are being investigated for creating conductive traces on fabrics to enable high frequency (up to 20 GHz) applications. In the inkjet printing, various surface treatments were considered and utilized to improve the ink-substrate interaction for the enhancement of adhesion of the deposited structures. Finally the RF losses of printed microstrip lines using the above techniques were analyzed, compared against the copper traces which are conventionally achieved by etching process.