Assessing the effect of discharge gap shape on high-speed electrostatic discharge events

This paper describes an assessment of electrostatic discharge (ESD) events in terms of electromagnetic interference (EMI) assessments. To clarify the characteristics of high-speed ESD events, we used two kinds of discharge electrodes: sphere-and cylinder-shape ones. We measured the energy level of ESD waveforms with charging voltages of 0.25, 0.5, and 1.0 kV. We found that the cylindrical electrode yields higher high-speed ESD energies, especially when the charging voltage was high; this indicates that the discharge gap shape is an important factor in ESD events. We estimate that the characteristics of high-speed ESD events can be influenced by the pressure variations in the discharge gap.