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Member
Total Posts: 265
Joined 2008-07-05
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Electro Static Discharge (ESD) is the sudden and momentary electric current that flows when an excess of electric charge, stored on an electrically insulated object, finds a path to an object at a different electrical potential (such as ground). The term is usually used in the electronics and other industries to describe momentary unwanted currents that cause damage to electronic equipment.
Causes of ESD
One of the causes of charge separation that creates an ESD event is the triboelectric effect, in which certain materials become electrically charged after coming into contact with another different material and then being separated. This is why people experience ESD events after walking on a rug, descending from a car, or removing some types of packaging. In all these cases, friction between different materials causes triboelectric charging that, when discharged, becomes ESD.
Prevention of ESD
ESD is a serious issue in electronics, because integrated circuits are made from semiconductor materials such as silicon and insulating materials such as silicon dioxide, which can break down if exposed to high voltages. Manufacturers and users of integrated circuits must take precautions to avoid this problem. Such measures include appropriate packing material, the use of conducting wrist straps and foot-straps to prevent high voltages from accumulating on workers' bodies, anti-static mats to conduct harmful electric charges away from the work area, and humidity control, because in humid conditions the surface layer of moisture on most objects conducts electric charges harmlessly to earth. Also, insulating materials prone to triboelectric charging should be kept away from sensitive devices as the charge accumulated on them can induce charge in the devices.
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