Static Electricity and Electrostatic Discharge
The fundamental aspect of matter which permits the flow of electricity is the existence of free electrons in that matter. The electrical resistance of a material is defined by how many electrons exist in the material. Metals, for example, have many free electrons so it is relatively easy to generate a current flow from them. Insulators, on the other hand, have relatively few free electrons, so current flow is, therefore, lower. The characteristics of insulators is that they do not allow the redistribution of electrical charge across their entire surface. This keeps a local electrical charge from building up. This is static electricity, and it leads to electrostatic discharge (ESD) that damages electronic devices.
Electrostatic Discharge (ESd):
The rapid (uncontrolled) transfer of charge between bodies at different electrical potentials, in many cases in the form of a spark.
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Typical Situations Generate Static Electricity
Moving an insulator or un-grounded conductor through a system.
Forcing fluid (gas or liquid) over the surface of an insulator or
un-grounded conductor.
Two solids sliding against each other (static will generate on surface
of insulator or un-grounded conductor)
Placing an insulator or un-grounded conductor in an electrostatic field.
Static electricity is more likely to develop in a dry atmosphere (i.e. cleanroom) than in high humidity.
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Wafer Comb Made of
SEMITRON ESd
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