Testing of the front-end hybrid circuits for the CMS Tracker upgrade

The upgrade of the CMS Tracker for the HL-LHC requires the design of new double-sensor, silicon detector modules, which implement Level 1 trigger functionality in the increased luminosity environment. These new modules will contain two different, high-density front-end hybrid circuits, equipped with flip-chip ASICs, auxiliary electronic components and mechanical structures. The hybrids require qualification tests before they are assembled into modules. Test methods are proposed together with the corresponding test hardware and software. They include functional tests and signal injection in a cold environment to find possible failure modes of the hybrids under real operating conditions.