Automated CNC Micromachining for Integrated THz Waveguide Circuits

Abstract

Computer Numerically Controlled (CNC) machining of splitblock waveguide circuits has become the primary method of constructing terahertz waveguide circuits. The majority of these circuits have been made on traditional CNC machining centers or on custom-made laboratory machining systems. At both the University of Arizona and Arizona State University, we have developed techniques for machining splitblock waveguide circuits using purpose-built ultra high precision CNC machining centers designed for micromachining. These systems combine the automation of a traditional CNC machining center, including a high capacity toolchanger, workpiece and tool metrology systems and a large work volume, with the precision of custom laboratory systems. The systems at UofA and ASU are built by Kern Micro and deliver typical measured dimensional accuracies of 2-3 microns. Waveguide surface finish has been measured with a Veeco white light interferometric microscope to be Ra~75 nm. Tools of sizes between 25 microns and 10mm are available, with toolchanger capacities of 24-32 tools.