Electronic Assemblies

All About Electrostatic Discharge

By October 5, 2018 March 4th, 2019 No Comments
electrostatic discharge

Electrostatic discharge is what happens when the flow of electricity between two objects that are electrically charged is suddenly shorted by contact between those two objects. This happens because there has been a buildup of static electricity between the two objects. Static electricity can build up between objects due to tribocharging or by electrostatic induction. Usually, when electronstatic discharge occurs, there is a visible spark of electricity between the two electrically charged objects that were brought together.

In fact, electrostatic discharge can produce amazing electrical spark shows. In the natural world, lighting that is accompanied by the sound of thunder is a large electrostatic discharge event. Other times, electrostatic discharge may produce to sparks or noise at all. However, even when it is unnoticed, electrostatic discharge can still cause damage to electronic devices.

Industries that use electrical devices have to constantly be on guard against electrostatic discharge. It can have harmful effects on a variety of industries. It causes explosions in natural gas, vapors of auto fuel, and in coal dust. It can also destroy integrated circuits. Because of the dangers to products and instruments from electrostatic discharge, the manufacturers of electronics have established areas in dangerous environments that are static-free. These are electrostatic-safe areas. The creation of these areas is done by taking measures to prevent charging and to remove static, usually using grounding of human workers, supplying antistatic devices, avoiding highly charged materials, and controlling the humidity in an environment that might otherwise be prone to electrostatic discharge.

Tribocharging, which is a common cause of static electricity, can be accomplished through a variety of means. Walking on a rug is an example of tribocharging, as it brings two electrically charged materials (the human and the rug) together, then quickly separates them. Rubbing a plastic comb on dry hair is another example of tribocharging that produces static electricity. Rubbing a balloon against a piece of wool, getting up from an upholstered car seat, and taking certain types of plastic packaging off of a product all tribocharge and produce static electricity. When one of the tribocharged items touches another charged item, a spark may be seen or felt, and electrostatic discharge occurs.

Electrostatic discharge can also occur via electrostatic induction. This happens when an object that is electrically charged is put near an object with conductive properties that is not touching the ground. The charged object creates a field of electrostatic energy that redistributes the electrical charges on the surface of the non-grounded object. When this happens, the un-grounded object now has areas where there is an excess of positive and negative charges on it. Electrostatic discharge may occur when the un-grounded object touches something with conductivity. An example of this is the surface of styrofoam cups. They can cause electrostatic induction on nearby sensitive objects, and electrostatic discharge may occur if they are touched with anything made of metal.

Most spacecraft are prone to electrostatic discharge because of charged particles pinging against them. This causes increased charging on the surface, making them prone to electrostatic discharge.

The most dangerous part of electrostatic discharge is the spark, which can cause minor pain to people, and severe damage to electronic equipment. In areas where the air is charged with combustible gases and/or particles, it can cause fires and explosions.

However, even without a spark, damage from electrostatic discharge can occur. Even tiny amounts of discharge can damage electronics, either by breaking them completely or by making them more prone to degradation over time (which affects their long-term reliability and performance).

Because so many electronic components can be damaged by electrostatic discharge, it is necessary to protect against it. Sensitive materials need to be protected even during their manufacture, as well as afterward, and during shipping and assembly, as well as the finished product. An effective and important method of preventing electrostatic discharge is grounding. Grounding needs to be regularly done and regularly reevaluated to make sure it is still in the proper position to be effective.

While electrostatic discharge is a natural phenomenon, it can damage electronic equipment, hurt humans, and even damage workplaces and cities. With the proper safety precautions in place, it can be minimized or prevented. This is good for the safety of all.