Hot spot detection in integrated circuits laterally accessing to their substrate using a laser beam

This work presents an approach to detect hot spots in active Integrated Circuits (IC) and devices. It is based on sensing the hot spot heat-flux within the chip substrate with a probe-laser beam. As the beam passes through the die, it experiences a deflection directly proportional to the heat-flux found along its trajectory (Internal InfraRed-Laser Deflection technique, IIR-LD). The proposed strategy allows inspecting the chip through its lateral sides (lateral access), avoiding the metal and passivation layers placed over the die.