Additively Manufactured RF Interconnects for D-Band/sub-THz Applications

The rapid development in micro additive manufacturing (μAM) of metals has the potential to enable a new generation of miniaturized devices capable of achieving complex 3D geometries that can be integrated with other conventional manufacturing methods, paving the way for a new range of applications across multiple fields. In this work, a novel metal micro additive manufacturing method is utilized to demonstrate for the first time the fabrication of micro-scale interconnect structures capable of operating up to 150 GHz. The μAM process consists of a localized electrodeposition process that utilizes an atomic force microscope cantilever tip, which can achieve printing resolutions in the order of microns. The interconnect structures were 3D printed and aligned to a CPW transmission line on a high-resistivity 15-by-15 mm Si substrate, which was prepared utilizing a photolithography process. This fabrication approach has the potential to enable the next generation of additively manufactured devices targeted for sub-THz applications with stringent requirements of good resolution and high conductivity.