Vulnerability of Electronic Devices to Atmospheric Charging

Static electricity

Static electricity is an imbalance in the amount of positive and negative charges within the surface of an object. There is a strong e-field around these charges whether the charges are moving or still.  Contact induced charge separation causes instant static discharges in the form of unnoticed sparks. Static electricity in the atmosphere is in an unbalanced state remains at that way until the potential gradient, between clouds, reaches a level that causes the insulator between clouds, in this case air, to break down or fail and lightning is created to equalize the potential gradient.

The sudden flow of static electricity or Electrostatic discharge (ESD) can interfere with the operation of electronic devices. Electrostatic discharge is the sudden flow of electricity between two electrically charged objects caused by contact, an electrical short or dielectric breakdown. ESD can create spectacular electric sparks (lightning, with the accompanying sound of thunder, is a large-scale ESD event), but also less dramatic forms which may be neither seen nor heard, yet still be large enough to cause damage to sensitive electronic devices.  ESD produces very high current waveforms and fast magnetic (H-field) or electrostatic field (E-field) disturbances.

It has at least one of three components, localized heat generation, high current density and high electric field gradient; prolonged presence of currents of several amperes transfer energy to the device structure to cause damage. During a natural spark of lightning strike, the potential difference between a cloud and ground, or between two clouds, is typically hundreds of millions of volts. The resulting current that flows through the ionized air causes an explosive release of energy. During an electrostatic discharge, the intervening atmosphere becomes electrically overstressed.

These can induce very high voltage or current in nearby sensitive circuitry and cause damage to electronic device. Such things happen if the electronic device is either on or switched on during or shortly after electrostatic discharge from the atmosphere into the electric device or electronic/electric circuitry and poses a constant danger to electronic devices, especially during raining and stormy climatic conditions.

When working with sensitive electrical components or volatile materials (such as papers/powders/flammable liquids) sparks and electrical discharge can cause catastrophic failure in sensitive electrical components and ignite volatile substances. Nonconductive objects can be damaging charge carriers even without any sparking or obvious effect. This occurs due to the formation of very small static electricity charge potentials when nonconductor come into contact with each other and then separate.

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