ABSTRACT
Thermal video systems (TVSs) are used in a variety of situations to identify and locate a broad range of faults on printed circuit board (PCB) assemblies. Circuit traces and components are often placed underneath dual inline packages where they are impossible to image directly. The presence of heat management components such as heat sinks and fins or thermal layers on the PCB can make all but the most limited IR inspections impossible. Batch operations usually consist of serial testing of a large number of identical boards. Metalized component surfaces with low emisivities such as the top surfaces of some integrated circuits make the task of package temperature measurement difficult. The majority of infrared NDT applications for PCBs are associated with situations other than mass screening. Recent communications indicate that there is substantial use of IR NDT for localization of shorts between traces and layers on PCBs.
