Aerosol Jet Printing of Millimeter Wave Transmission Lines on 3D Ceramic Substrates Made by Additive Manufacturing

This work presents the conformal printing of millimeter-wave transmission lines up to 67 GHz using inks based on silver nanoparticles. Several coplanar (CPW) lines have been printed over 3D Alumina test structures such as slope, half-sphere and ridge, all of them being fabricated using a ceramic additive manufacturing technology. All of the achieved transmission lines show a return loss better than 10 dB and insertion loss better than 0.8 dB up to 60 GHz. Extensive tests have been done on the performances obtained with the Aerosol Jet Printing (AJP) technology. Minimum features (line width, lines spacing) down to 16.5 µm have been obtained on flat surfaces (24 µm on 3D ceramic objects) while obtaining a high conductivity of 2.1 10⁷ S/m at 49.2 GHz for the directly printed silver layers.