Vulnerability of Electronic Devices to Atmospheric Charging

Protection with Faraday cage: Sensitive electronic devices need to be protected during shipping, handling, and storage. Faraday cage is a metal box designed to absorb the surge of an electric discharge without harming its contents. An antistatic bag, a bag made of a partially conductive plastic that acts as a Faraday cage, used for shielding the electronic device from ESD. These bags are usually plastic polyethylene terephthalate (PET) and have a distinctive color (silvery for metalized film, pink or black for polyethylene).

The polyethylene variant may also take the form of foam or bubble wrap, either as sheets or bags. Multiple layers of protection are often used to protect from both mechanical damage and electrostatic damage. Whatever it is being stored in the Faraday cage must be insulated from the inside metal surface of the box, but should otherwise remain protected. Accordingly, the box should be constructed so that no large gaps or holes are present.

The buildup and discharge of static can be minimized by controlling the surface resistance and volume resistivity of packaging materials. Packaging is also designed to minimize frictional or triboelectric charging of packs due to rubbing together during shipping, and it may be necessary to incorporate electrostatic or electromagnetic shielding in the packaging material. A common example is that semiconductor devices and computer components are usually shipped in an antistatic bag made of a partially conductive plastic, which acts as a Faraday cage to protect the contents against ESD.

Other methods: For most home and commercial electronic devices, surge protectors and lighting arrestors serve to protect the systems from failure in the event of a power outage–fortunately they will also protect them against the effects of an electrostatic discharge.  While a powerful surge could wipe out the grid and shut off electrical services, the devices themselves would not be harmed if plugged into a surge protector.  However, they would need to be run on a backup power source in the event of this happening.

Next Page: Some precautions

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