C. Schmidt, F. Altmann, C. Grosse, F. Naumann, Fraunhofer Institute for Mechanics of Materials, Halle, Germany

Summary: Lock-in-Thermography (LIT) is a new approach for non destructive defect localisation inside packaged devices. This paper will present further improvements of the LIT method locating electrical defects like shorts and resistive opens inside of complex three dimensional devices. Different test samples with defined heat sources and additional thermal simulation were used to investigate heat transfer through a packaged device and optimize LIT parameters. For three dimensional hot spot localisation the phase shift between the stimulation of the defect and the correspondet thermal signal at the device surface were investigated.