Millimeter-wave surface mount technology for 3-D printed polymer multichip modules
Board level integration of novel all-in-polymer 3-D printed multichip modules process (MCM-P) at millimeter-wave frequencies is presented. The modules were manufactured using additive 3-D printing technologies based on mask-defined gradual photopolymerization in the z-direction. A lead frame structure was introduced resulting in a quad-flat no-lead footprint of 0.5-mm pitch. The front-side of the modules integrated transmission lines of the centered stripline type for interconnecting embedded millimeter-wave monolithic integrated circuits up to D -band (110-170 GHz). Broadband surface mount transitions from the MCM-P front-side interconnection layers to a high-frequency printed circuit board (PCB) were investigated. Dual channel test modules were characterized in back-to-back configuration, representing the integration needs of millimeter-wave multiple-input-multiple-output systems. The de-embedded PCB transition exhibited an insertion loss of less than 2 dB up to 75 G Hz and less than 1 dB up to 60 GHz with a return loss better than 10 dB.