High-Frequency Transmission Characteristics of the Interconnects Stacked into the 3D IC Configuration

Abstract

We evaluated the high-frequency signal-transmission characteristics of fan-out interconnects integrated in a three-dimensional integrated-circuit (3D IC) structure built with SMAFTI (SMArt chip connection with FeedThrough Interposer) packaging technology. The S-parameter measurements of the interlaminar horizontal wiring up to 40 GHz confirmed the potential of this wiring for transmitting signals at speeds of over 10 Gb/s. We also evaluated the transmission losses due to transitions such as die-edge crossing, interlayer vias, and right-angled bends, and confirmed that these transitions had little impact on the signal transmission characteristics.