Defect Localization by Lock-In-Thermography

This presentation provides an overview of lock-in thermography and its application in semiconductor failure analysis. It begins with a review of direct thermal imaging, IR transmission and detection, and the fundamentals of lock-in measurements. It compares and contrasts steady-state IR imaging with lock-in thermography and shows how lock-in frequency and the shape of the excitation signal can be varied to increase signal-to-noise ratio and reduce acquisition time, thereby exposing a wider range of defects. It also presents several case studies in which lock-in thermography is used to diagnose shorts and hot spots in packaged devices, electronic systems, and 3D assemblies.