By simply moving, a person makes static electricity. When this happens, coming in contact with a conductive material will result in a rapid discharge of static from the body. This is what’s known as ESD = Electrostatic discharge. Static electricity is becoming a major problem in the electronic manufacturing industry. Normally, no one notices because our bodies don’t feel discharges below 3000 volts. We may see ESD above 5000 volts as a spark. A lot of standard components are sensitive to charges of 100 – 200 volts and the most sensitive components may be damaged by a charge of merely 30 volts. When manufacturing electronic equipment, it is essential to regularly and correctly measure your ESD control.
Here are some essential tips for measuring all components of your ESD workstation.
- · When you measure your ESD control on your work surface, place your probes on the tabletop, spaced a minimum of 25 cm apart and at least 5 cm from the top edge.
- · With shelves and tables, place one probe on the work surface and the other probe on the table or shelf. Your point-to-point resistance should be < 1x10⁹ Ω
- · For flooring, put 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 the other 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, make sure chair wheels are cleaned with ESD detergent.