Electrical QC Testing of Pixel Modules in the ATLAS Inner Tracker Upgrade for the HL-LHC

The upgrade Inner Tracker (ITk) for the ATLAS detector in the HL-LHC era is in its production phase. About 10000 hybrid pixel modules will be produced for the pixel detector in this all-silicon tracker. The electrical performance of these modules during quality control (QC) is assessed on the 3D and planar sensors, the RD53 frontend chip and on the module as a whole. A pixel module consists of 3 or 4 frontend chips. The interplay between the chips is derived from first principles and is evaluated during QC on the testbench. In addition to the typical leakage current measurement and chip calibration and tuning, our QC also tests the novel features of this chip that allows the radiation length of the detector to be minimised. These features include the shunt-LDO (SLDO) circuit which enables powering of multiple modules in a serial chain and on-detector data aggregation. The assembly and testing of these modules are performed at about 25 sites worldwide, thus it is of utmost importance to ensure the consistency and uniformity of the testing procedures. For this purpose, we have developed a modular testing suite based on python that is easily installed and automates tasks like interacting with the production database, conducting tests with pre-defined procedures, interpreting the measurements and the creation of a test report.