Electrostatic discharge (E5D) is extremely harmful, especially to integrated circuits and semiconductor devices. If electrostatic discharge occurs on the electronic components, it can cause damage to the electronic components; in the lighter case, the diode can be broken down, and in the worst case, the integrated circuit can be damaged. Especially in the IC production workshop, once the anti-static measures in a certain process are not perfect, it may cause batch products to be scrapped. After the RS232 interface chip is damaged by 15kV (general test level) electrostatic discharge impact, the chip is not equipped with electrostatic protection measures. The instantaneous large current generated during electrostatic discharge vaporizes the metal inside the chip, causing large-area damage . Especially the C9d()S circuit and the M10S field effect tube have very high input impedance and very small input capacitance. Even if a small amount of charge is induced at the input terminal, it will form a high voltage and damage the device. When the fluorescent nixie tube on the electronic instrument is negatively charged, it can cause the display pen segment to be incomplete or even not to display. The solution is to scrub the glass tube shell with anhydrous alcohol cotton ball, and discharge the electric charge stored on the surface of the glass shell to the ground through the human body. A better solution is to apply a layer of medical ringworm potion around the shell. This syrup is conductive and has strong adhesion. Once volatilized, the place where the syrup is applied still maintains conductivity, which can prevent the accumulation of electric charge during electrostatic induction.
The human body is one of the important sources of static electricity. When a person walks or exercises, a voltage of several thousand volts may be generated. If it is not controlled, it will discharge electrostatic sensitive objects. When the human body is electrified, it is capacitive, and when the human body is anti-electric, it is equivalent to a resistor. Therefore, the series circuit of equivalent capacitance and equivalent resistance can be used to simulate the human body impedance model. At present, the more recognized human body impedance model is made up of a 100pF capacitor in series with a 1.5kΩ resistor. Its rise time/J is less than 10ns, and its fall time is about 50ns to 300ns. Human body impedance includes skin impedance and body impedance, and skin impedance is also related to factors such as contact area, ambient temperature, humidity, and breathing conditions.
