Effect of discharge electrode and body geometry on the relative probability and severity of the ESD event in electronic systems

Capacitance coefficients are measured for electrostatic discharge (ESD) in a basic two-conductor system, simulating the approach of a charged object (the human body) to a second object which can be floating or grounded (the equipment under test). Parameters studied include the size of the conductors, the size and relative position of the discharge electrode, the separation between the discharge electrode and the second body, and the position of the bodies relative to a horizontal ground plane. System equations based on Maxwell´s technique are solved to yield the body potentials and the electric field in the air gap between the discharge electrode and the second body. The relative probability of a discharge and severity of the discharge event are compared for the various configurations. The results not only show how the studied parameters affect the ESD event, but also provide a better understanding of the phenomenon based on the distribution of electric flux between the two bodies and ground.<>