Laser Seebeck Effect Imaging (SEI) and Peltier Effect Imaging (PEI): complementary investigation methods
Résumé
We present in this paper the comparison of two imaging techniques dedicated to the detection of faults in integrated circuits. These techniques are based on thermoelectric effects occurring when a laser beam heats junctions on integrated circuits or when current flows through the same junction. The first one called Seebeck Effect Imaging (SEI) consists in measuring the thermoelectric voltage appearing when a laser beam heats the circuit surface while in the second the laser is used to measure the Peltier temperature field induced by the current flow through thermoelectric junctions. We have compared these two complementary techniques based on reciprocal phenomena. We present a simple analytical model to explain the SEI and PEI signals and relate it to reliability analysis.