Aerosol-Jet-Printed Ramp-Based Interconnects from DC to D-Band

This paper explores the feasibility of ramp-based Aerosol Jet (AJ) printed interconnects for radio frequency applications from DC up to the D-Band (110 to 170 GHz). Utilizing off-the-shelf RF PCB materials, a proof-of-concept assembly was designed, fabricated, and tested. The interconnect was printed between two CPW segments on two PCBs placed on top of each other and connected by a ramp of 80 μm height and 200 μm length. Their performance was evaluated through measurements and was found to be in good agreement with the simulations.The results demonstrate a verified operational bandwidth of 153 GHz (DC to 153 GHz) with a return loss better than 10dB and an insertion loss ranging from 0.31 dB to 1.41 dB. The reflection loss is better than 8 dB in the entire frequency range from DC to 170 GHz. A challenge in the fabrication process was the formation of a thin insulation layer on the CPW lines during ramp dispensing, which degraded the interconnect performance. This issue was mitigated through a novel glue scrubbing process by laser ablation, significantly improving the electrical contact and overall performance.