In ordinary movement, a person makes static electricity. In these circumstances, hand contact with a conductive material will discharge static from your body very quickly. This is called ESD = Electrostatic discharge. Static electricity has become a major problem for electronics manufacturers. Typically, this passes unnoticed because humans don’t feel discharges under 3000 volts. We may see ESD above 5000 volts as a spark. The most sensitive components may be damaged with a charge of merely 30 volts, and a lot of standard electronics are sensitive to charges of 100 – 200 volts. When manufacturing electronic equipment, it is vital to regularly and correctly measure your ESD control.
Here are a handful of essential tips to measure all the parts of your ESD workstation.
- · When measuring your ESD control on your work surface, place your probes on the tabletop, spaced at least 25 cm apart and at least 5 cm from the top edge.
- · With tables and shelves, put one probe on the work surface and the other probe on the table or shelf. Your point-to-point resistance should be < 1x10⁹ Ω
- · With flooring, place one probe on your work surface and one probe on the ESD floor. Your point-to-point resistance should be < 1x10⁹ Ω
- · Test the common point ground by placing the probe on the tabletop and measure the system’s total resistance between the tabletop and the common point ground using a measuring lead.
- · Chair ESD, place one probe on the seat of the chair and one probe on a metal plate under one of the chair’s wheels. Your point-to-point resistance should be < 1x10⁹ Ω (with upcoming standard < 1x1010 Ω). For best results, be sure chair wheels are cleaned with ESD detergent.