Front-end Electronics of the Forward Strip Detector for the ATLAS HL-LHC Upgrade

The ATLAS Experiment will upgrade its central tracking detector with an all-silicon Inner Tracker (ITk) for the HL-LHC, comprising pixel and strip detectors. The strip detector is based on silicon strip sensors, which are read out by low mass, radiation hard circuits carrying custom designed radiation hard ASICs in 130 nm technology. The circuits are made from flexible PCB multi-layer copper polyimide constructions. The ASICs are glued onto the flex and connections are made by wire-bonding. This contribution discusses the evolution and electrical performance of various hybrid prototypes necessary to equip the forward region of the detector, as well as their final development.