Assembly and Quality Control tests for ME0 GEM Detectors for CMS, CERN

The LHC will be upgraded in many phases for the high luminosity - LHC (HL - LHC) known as Phase II upgrade that will be between 2026 and 2028 (LS3). After this major upgrade the LHC will operate in higher Energy that will reach 14 TeV (or 7000 GeV / Beam), and the final luminosity will exceed 5 × 1034 / $cm^{2}s^{1}$ , five times more than the original design value. To handle the increase in background activity and trigger demands, new muon detectors using Gas Electron Multiplier (GEM), ME0, technology are being added and will be installed in the CMS in the LS3 in the interval mention above. In this paper we present a detailed procedure about the assembly process in our site (904 lab, Prévessin site, CERN) and the Quality Control tests (QC3 QC4) as well.