ESD Systems - Questions And Answers

We are in the process of changing out all our CRT monitors to flat screen monitors. More so to safe space at the work station. I measured a flat screen using a field static meter and didn't see any spikes like you would with a CRT monitor. My question is: Is there anything in 20.20 that references what type of of monitors to use and minimum distances of CRT monitors and flat screens from ESD assemblies?

Thank You,
John Hager

There is no specific comment about computer monitor screens in either ANSI/ESD S20.20. ESD Handbook ESD TR20.20 section 5.5.1 says “Equipment known to generate electrostatic charges or fields include those constructed from: latex, silicone and similar materials which are often used in vacuum assisted processes, pneumatic conveyors, flow soldering equipment and solder pots, conveyor belts and transit systems, and display screens.” Older monitor screens were major generators of electrostatic charges. The concern for newer monitors is typically the high charging plastic of the frame. The general rule is to keep ESD sensitive 12” from electrostatic fields that are considered a threat. The ability of surfaces to charge can be measured using a static field meter. Reztore™ Topical Antistat can be periodically applied to surfaces to make low charging. Per ANSI/ESD S20.20 section 6.2.3.2: “All process essential insulators that have electrostatic fields that exceed 2,000 volts should be kept at a minimum distance of 12 inches from ESDS [ESD sensitive] items.”

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