3-D Printed Substrates for MMIC Packaging

Though 3D printing has been leveraged to realize passive components, it remains largely unexplored for the packaging of active devices and circuits. In this paper, a bare GaAs LNA MMIC is wire-bonded in a 3D printed substrate for the first time. The package's metal layer was deposited via sputtering and patterned using a mask-less process enabled by the use of grooves during the printing process. Up to 10 GHz, the packaged LNA shows a maximum gain of 25.5 dB. At higher frequencies, the loss of the package increases due to surface roughness and interconnect effects, as well as a suspected increase in the substrate's loss tangent. These remain critical issues for future 3D printing-based microwave and millimeter-wave packaging.