Polymer multichip module process using 3-D printing technologies for D-band applications

A novel all-in-polymer multichip module (MCM-P) process is presented for applications at D-band (110-170 GHz). The unique manufacturing approach is an additive 3-D printing approach based on a gradual photo-induced polymerization in the z-direction with metallized interconnection layers in between. The package design integrates a broadband waveguide transition nearly covering the entire D-band. Different transmission-line types for chip interconnections were characterized up to 170 GHz. In prior research, a millimeter-wave monolithic integrated circuit (MMIC) amplifier using a 50-nm metamorphic high electron-mobility transistor technology was designed. In this study, the co-design with the package is presented. The amplifier MMIC was bond-wire free embedded in an MCM-P test structure and contacted with coplanar measurement probes. A gain of more than 20 dB within 100-170 GHz was measured. Based on those results, an amplifier MCM-P with integrated waveguide transitions of size 6 mm × 4.5 mm was developed. The MCM-P was surface mounted on a printed circuit board and flipped into a waveguide test fixture. A gain of more than 20 dB remained from 125 to 155 GHz with an input and output matching better than 10 dB.