Cryogenic packaging for multi-GHz electronics

To meet the packaging needs of current superconducting electronics, we have developed high speed multi-chip modules (MCMs), flexible ribbon cabling, a nd press-contact surface mounts. We describe these new technologies and inc lude techniques for high-reliability, high-yield assembly. In addition, we present electrical and thermal characterizations of a system which incorpor ates these new technologies. Electrical characterization includes multi-GHz insertion loss and digital-data transmission measurements. We have perform ed extensive thermal modeling using SINDA software and have experimentally verified these simulations. We present the results and their general applic ability to these new cryogenic packaging technologies.