Usually, there are many integrated circuits in a device. When receiving a faulty integrated circuit device, the first step is to determine the general location of the fault based on the fault phenomenon. Then, through measurement, the possible location of the fault is gradually reduced, and finally the fault is located. The visual inspection method is to observe whether the appearance of an integrated circuit is different from normal through the eyes, in order to determine whether the integrated circuit is damaged. Its main maintenance skill is to see which appearance is damaged. The normal appearance of an integrated circuit is clear handwriting, undamaged material, smooth surface, and rust free pins. The damaged surface of an integrated circuit is cracked, cracked, or scratched, with small holes on the surface. Missing corners, missing blocks, etc. Sensory method is to experience whether the integrated circuit is normal through the human body's senses. The main senses include touch, hearing, and smell. The sensory method includes whether the surface temperature of the integrated circuit is too hot, whether the heat sink is too hot, whether it is loose, whether it emits abnormal sounds, and whether it produces abnormal odors. The tactile sense mainly relies on feeling the temperature by hand, and playing the integrated circuit by hand to perceive the firmness. Sensing temperature is the process of determining whether an integrated circuit is heating abnormally, that is, whether it is overheating, based on the thermal effect of the current. The normal temperature of integrated circuits is between -30-85 ℃, and they are generally installed away from heat sources. The factors that affect the temperature of integrated circuits include working environment temperature, working time, chip area, integrated circuit structure, storage temperature, and materials and areas with heat dissipation fins. Overheating is often considered from the speed of temperature rise, duration of temperature, and peak temperature