In ordinary movement, a person generates static electricity. Under these circumstances, making contact with a conductive material will discharge static from the body very quickly. This is what’s known as ESD = Electrostatic discharge. Static electricity is a big problem for the electronics industry. Usually, no one notices because humans don’t feel electrostatic discharges below 3000 volts. We may see ESD over 5000 volts as a spark. The most sensitive components may be damaged with a charge of only 30 volts, and a lot of standard electronic components are sensitive to charges of 100 – 200 volts. When manufacturing electronic equipment, it is vital to measure your ESD control regularly and correctly.
Here are a few 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 at least 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 on the table or shelf. The point-to-point resistance should be < 1x10⁹ Ω
- · For flooring, put one probe on your work surface and the other probe on the ESD floor. Your point-to-point resistance should be < 1x10⁹ Ω
- · Test the common point ground by placing the probe on your tabletop and measure the system’s total resistance between the tabletop and the common point ground using a measuring lead.
- · With 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 have been cleaned with ESD detergent.