This paper describes a systematic approach to characterize flip-chip solder bump interconnects to accurately design mm-wave on-chip devices and matching circuits for on-package components. Variety of on-chip test structures are fabricated and measured from DC to 67 GHz by GSG probes landed on bare and bumped pads. Combination of two double-delay based de-embeding methods are used to calculate the transmission lines (TLs) and interconnect characteristics. Furthermore, scattering parameter of bare pads and bump pads are accurately extracted from measurement results without lumped element assumption.