Because the human body will contact and rub with various objects and components, it is easy for the human body to carry static electricity, which will cause electrostatic damage to components. It is generally believed that the electrostatic damage of most components is caused by human static electricity. The human body with static electricity can be equivalent to the equivalent circuit of figure 1.5, which is also called the human body model.

2.CMD: discharge model of charging device.

In the process of assembly, transmission, testing, testing, transportation and storage of components, the shell will be charged with static electricity due to friction with other materials. Once the pin of the component is grounded, the shell will discharge to the ground through the core and pin. This form of discharge can be simulated as a so-called charged device.

Model, CDM).

3.MM: Discharge mode of charged machine.

Machines can also be charged by friction or induction. Charged machines can also be damaged by the discharge of electronic components.

4. It does not represent the maximum static electricity encountered in this paper.

Extended data

There are generally three modes of electrostatic discharge, HBM, MM and CDM. HBM is generally random, and it can be well controlled as long as the education of production line personnel and the management of electrostatic protection measures are well done.

At the same time, the protection level of devices against HBM discharge is usually high (≥2000V), while MM and CDM usually occur in fixed positions and are easy to recur. At the same time, due to the particularity of discharge mode and the limitation of anti-static circuit design, the equipment itself is usually weak in preventing CDM discharge, which is the object that needs special attention.

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