Developing Module Assembly and Quality Control Procedures for the HL-LHC Upgrade of the ATLAS Inner Tracker

To further probe the fundamental structures of matter, the Large Hadron Collider (LHC) at CERN is undergoing a programme of upgrades aimed at increasing the instantaneous luminosity by a factor 5 − 7. In lieu of this High Luminosity upgrade (HL-LHC), the current ATLAS Inner Detector will be replaced by a new large area all-silicon tracker - the Inner Tracker (ITk). This is a vast and complex undertaking, requiring the involvement of many institutes worldwide. A modular design philosophy is employed, such that the ITk will consist of 19.000 independent sensor modules, facilitating the need for mass-production, with pixel and microstrip n-on-p based sensor technologies being utilised. The Scandinavian ITk Cluster, consisting of physicists and engineers from Copenhagen, Lund, Oslo and Uppsala University, will be responsible for producing ∼ 600 of the microstrip type modules, in a close collaboration between academia and industry. This partnership has re- quired a redesign of many ITk baseline assembly procedures - to better suit the production line-up in industry. The work carried out during this project touched upon several aspects of the production pro- cedure. The primary product of the research effort described in this thesis, is the development of a robot for high precision high accuracy glue dispensing, both as to regards the placement and amount of glue. The two-component epoxy glue can be delivered with a precision of 2 mg, with clear avenues of improvement, over a time period of 50 min. It will be used in mounting the read-out, powering and control electronics on to the surface of silicon microstrip sensors - a most critical step of the assembly procedure. In addition to this, a study of early onset micro-discharge, seen in IV curves of the ITk silicon sensors labelled ATLAS12EC, has been carried out. Using NRA analysis techniques, we could show that the top oxide layers of several mini sensors had been contaminated with up to ∼ 7% hydrogen by atomic fraction, most likely due to prolonged humidity exposure - hinting at humidity being the cause for this early onset phenomenon.