Electrostatic Discharge Risks to Equipment

Humans become electrostatically charged as they do ordinary things such as walk across a carpet, walk across a vinyl floor, slide something inside a vinyl envelope, or slide their clothing across a workbench stool. Sensitive electronic components can be damaged either of two ways if an electrically-charged person discharges through them. 1) Discharge current can cause immediate catastrophic damage to a semiconductor junction, to a fine connecting-wire inside a semiconductor component, or to other sensitive parts. 2) Discharge current can cause latent damage that will cause one or more components to fail in the future even if they continue to function immediately after the event. The risks are highly dependent on relative humidity (RH), because humidity affects the amount of static charge that accumulates. For example, someone walking across a carpet at 15 percent RH will typically develop about a 35KV charge. The same person walking across the same carpet at 75 percent RH will typically develop only about 1.5KV of charge. ©2005 Tigertek, Inc. All rights reserved.

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