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2012-06-17

A+: More ESD Precautions

Caution!: All work mats and wrist straps should have a 1-megohm resistor, to stop any high voltage that comes through the ground line from injuring you!

Correct equipment storage should have two goals: Eliminating the possibility of ESD, and protecting equipment from impact damage.

To protect equipment from ESD, store equipment in the Faraday cage antistatic bags originally supplied with the equipment; retain bags for installed equipment for reuse. Faraday cage antistatic bags feature a thin metallic layer on the outside of the bag, which is conductive and prevents ESD from penetrating to the components inside. Thus, metalized metallic bags should never be used for temporary mats for components; if you lay a component on the outside of the bag, you’re laying it onto a conductive surface. Colored antistatic bubble wraps also work well for parts storage and can also be used as a temporary mat, too. If you use bubble wrap, make sure it is antistatic.

Store components in appropriate boxes to avoid physical damage. If the original boxes have been discarded, use cardboard boxes that have enough room for the component, the Faraday cage bag around the component, and antistatic padding.


A grounded wrist strap can help prevent ESD, but you should also follow these additional precautions:

• If you must handle expansion cards and other devices with chips without suitable antistatic protection, never touch the chips! Most current products use a CMOS (Complementary Metal-Oxide Semiconductor) design, which has practically no resistance to ESD; as little as 30V of ESD can damage CMOS-based devices.

    • Hold expansion cards by the brackets, never by the gold edge connectors, chips, or circuitry.

    • Wear natural fibers, such as cotton and leather-soled shoes, instead of rubber or synthetics, to avoid ESD buildup.

    • Use an antistatic spray (commercial or antistatic fabric softener/water mixture) to treat carpeting to reduce ESD.

    • Use antistatic cleaning wipes on keyboards, monitors, and computer cases to reduce static buildup. Turn off the power, and if you use a liquid cleaner, always spray the cloth, never the device!



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