Lock-in thermography for defect localization and thermal characterization for space application

Non-destructive failure analysis and defect characterization are necessary steps for every component that is destined to space projects. Infrared Thermography is a non-invasive, contactless technique providing information regarding defect localization as well as thermal characterization. The system used in CNES Expertise Laboratory is a DCG ELITE system equipped with an InSb camera that detects IR between 3 and 5 μm. Defect localization could be done in steady state observation, where the Device Under Test (DUT) is observed in nominal condition for hot spot localization. The spatial resolution for the localization of defect heat sources could be improved by a lock-in mode, also known as phase sensitive modulation thermography. Defective or not, the component can be thermally characterized by time related heat propagation. Here the origin of the heat source is visualized, and the temperature measurements give a thermal map of the DUT. Both defect localization and thermal characterization are possible on board and component level, and their utilization will be illustrated by studying case analyses.