Flip-Chip Interconnect for Coplanar Strip Lines

A flip-chip interconnect configuration with coplanar strip (CPS) lines on printed circuit boards (PCBs) is reported for millimeter-wave applications. For CPS lines, the signal and ground electrodes both lie on the top surface of a chip or substrate. The flip-chip configuration was designed and implemented using a test chip on a dielectric board. Geometrical parameter analysis was carried out using full-wave simulation and equivalent circuit model for wideband performance. The chip was connected to the board using solder bumps. For a typical flip-chip assembly, the measured insertion loss is less than 3dB for frequencies of up to 35GHz and the return loss is higher than 15dB for frequencies of up to 29GHz using CPS flip-chip configuration.