Studies in Baseplate-Pixel Sensor Gluing of the Pixel Strip Modules for the Compact Muon Solenoid Experiment Phase-2 Upgrade

The upgrade program, Phase-2 of the High Luminosity LHC (HL – LHC), is planned to increase instantaneous peak luminosities to 5.0 x 10³⁴ cm^-2 s^-1. This study focuses on the Pixel-Sensor (PS) Module which will be installed in the end cap region of the Compact Muon Solenoid (CMS) detector. In order to prolong the lifetime of the modules during operation, an efficient cooling system has to be embedded within the components. The contact between the module and cooling is provided by a glue layer. Therefore, the study outlines the advances and improvements made on the gluing techniques between the baseplate and pixel sensor of the pixel strip (PS) modules to meet specifications. The automated assembly was commissioned by DESY (Deutsches Elektronen Synchrotron) to increase the building efficiency of the modules. Using two types of epoxy glues, a fast curing, and slow curing glue, the specifications were achieved by exploiting the precision of the motion stage to achieve a thin glue layer with excellent coverage. The techniques were tested and produced promising results. Further studies on improving the method and assembly of modules are being done at the Detector Assembly Facility (DAF) at DESY in Hamburg, Germany.