Quality Control for DUNE Cryogenic FEMB Production

In Deep Underground Neutrino Experiment (DUNE), the Liquid Argon Time Projection Chamber (LArTPC) is chosen as the far detector (FD) solution. The first two 10 kton DUNE FD modules will employ anode planes with cold electronics (CE) installed inside the cryostat. The CE developed for cryogenic temperatures (77-89K) operation is an optimal solution that achieves excellent noise performance and decouples the electrode and cryostat design from the readout design. There are 384,000 channels from FD1 and 245,760 channels from FD2 to be read out by CE, which requires 4,920 Front-end Motherboards (FEMBs). DUNE is expected to be operated for 20 to 30 years, which requires FEMBs to stay in liquid argon (LAr) for 30 years without the possibility of any replacement and maintenance. Therefore, a stringent quality control (QC) method is studied to assure the robustness and reliability of FEMB. It requires that all system aspects are considered starting from the early design phase to the detector commissioning phase. We summarize the design of cryogenic FEMB, experiences gained from pre-production, and QC testing method optimized for batch production.