What is Electrostatic Discharge (ESD)?

Electrostatic discharge (Electrostatic Discharge) refers to the charge transfer caused by objects with different electrostatic potentials approaching or directly contacting each other.

ESD is a common near-field hazard source, which can form high voltage, strong electric field, instantaneous high current, and accompanied by strong electromagnetic radiation, forming electromagnetic pulses of electrostatic discharge.

· Current> 1A

Rise time ~ 15ns, decay time ~ 150ns.

In the electronics manufacturing industry, there are many sources of static electricity, such as the human body, plastic products, related equipment and electronic components.

The human body is the most important static power source. There are three main aspects.

The form of electrostatic discharge and

The most common cause of electrostatic electrification is contact and separation of two materials. Most frequently occurring static

After removing or connecting the cable

The International Electrotechnical Commission (Internationa on the 1st ectrotechnicalCommission, IEC) has developed a test standard IEC61000-4-2 to evaluate the ESD immunity level of electronic equipment. However, when people are studying the harm of electrostatic discharge, they are mainly concerned about the harm of injected current generated by electrostatic discharge to electric explosives, electronic devices, electronic equipment and other electrostatic sensitive systems, and they ignore the electromagnetic pulse effect of electrostatic discharge until In the early 1990s, Wilson first proposed the effects of radiation fields generated during the ESD process. Although the IEC61000-4-2 standard has been modified several times, it regulates the discharge mode of the horizontal coupling plate and vertical coupling plate by the ESD simulator, but there is no clear regulation on the ESD radiation field, and the ESD simulator only specifies the typical waveform of the discharge current. And 4 key point parameters. The equipment under test (equip-mentundertest, EUT) is usually susceptible to electromagnetic fields. Many scholars found in actual tests that due to the internal relay and ground loop of the ESD simulator, the test results obtained by different END simulators that meet the requirements of the IEC61000-4-2 standard are not the same.

The current test methods and experimental platforms specified in the IEC61000-4-2 standard still have certain limitations, and further research and improvement are needed. Standardization international organizations such as ESD Association WG14, ANSIC63.16 and IECSC77BWG9 are working hard to improve the consistency of the electrostatic discharge immunity test, and have extensively discussed and improved the existing standards. However, not much work has been done in related fields in China. The current ESD immunity test standard is based on the original IEC standard, and the formulation and modification of the standard is not in line with international standards, so it still lags behind Western developed countries in the ESD immunity test.