Marius Preuten (Rheinisch-Westfaelische Tech. Hoch. (DE))
For the Phase2-Upgrade of the CMS Silicon Tracker new double-sided modules are foreseen, providing track information to the first trigger stage of CMS. Hence two strip sensors, positioned on top of each other at a small distance (~3 mm), will be part of a single module, allowing for a combined readout using a single front-end-chip. From the correlation between hits in both layers within one front-end, tracks can be filtered on their transverse momentum for the first trigger stage (min. 2 GeV). In this schema, the relative sensor-to-sensor alignment within one module plays a crucial role, since for the first trigger stage it cannot be corrected using software alignment techniques. Therefore all modules will be required to fulfil rigorous quality criteria. To verify the assembly accuracy, especially the relative sensor placement, it is required to relate measurements from the opposite sides of the module with high accuracy to each other. In absence of a commercially available solution, a prototype for a double-sided metrology machine has been developed at RWTH Aachen University. Apart from the general measurement method, results on achieved accuracies will be presented, as well as the ongoing work on a full scale double-sided metrology set-up. Furthermore the potential usage during the module production will be discussed, in conjunction with possible module assembly strategies.