Printing And Measurements Of Ink-Jet Deposited Transmission Lines For Space Electronics

This paper demonstrates the ink-jet printing of a coplanar waveguide (CPW) transmission line on Kapton (TM) and Willow Glass substrates for space electronics. A customized Nordson EFD fluid dispensing system with xQR41 Series MicrodotTM needle valve was used to print CPW transmission lines using DuPont 5025 conductive paste with feature sizes approximately 200 mu m. The printing challenges related to viscosity of ink, deposit size, and fluid inlet pressure were identified and solutions are provided. The characterization of the propagation constant and reflection coefficient of the CPW lines have been carried out using a multiline TRL calibration technique. Additionally, the PNA was calibrated to the probe tips using a GGB Picoprobe Short-Open-Load-Thru (SOLT) calibration standard wafer for measuring the CPW lines over a broader bandwidth (up to 50 GHz). The RF power handling capability and the adhesion tape testing results of the CPW lines are also presented. At 10 W input power, the Kapton bent upwards and the CPW line discolored. Despite all these observed variations, the CPW line operated well.