Embedding and Interconnecting of Ultra-Thin RF Chip in Combination with Flexible Wireless Hub in Polymer Foil

Abstract

a flexible and adaptive energy-efficient high-speed wireless hub is developed as a Hybrid System-in-Foil (HySiF) using CMOS compatible Chip-Film Patch (CFP) technology. In this matter, the SiGe BiCMOS silicon chips (2.39 × 1.65 mm2) are thinned down to 45 µm and are embedded face-up inside a two-polymer CFP flexible foil carrier. The active pads of embedded silicon chips inside foil are extended to the surface of the foil and interconnected to the antenna fabricated on the foil using an adaptive layout technique. A thin chip power amplifier (PA) is embedded in flexible polymer foil and is interconnected to the antenna with a signal transmission at 5.5 GHz. The overall thickness of system is below 100 µm and, thus, has bendability down to 4 mm radius of curvature.