Level Estimation of Transient Electromagnetic Fields Caused by Spark Discharge between Charged Metal Spheres

Abstract

It is well-known that transient electromagnetic fields caused by low-voltage electrostatic discharge (ESD) often gives a fatal shock to digital information equipment. This peculiar properties can qualitatively be explained by our previously proposed dipole model having a spark current, whereas the model is unable to predict any effects of charged metals on the ESD field level. This paper proposes a new ESD source model for estimating the transient field level caused by the spark discharge between charged metal spheres. The new model consists of numberless image dipoles placed so as to keep the same potential on the metal surface, which enables us to calculate the ESD field level by superimposing the fields due to each image dipole. In order to verify the validity of the new model presented here, we measure through a shielded loop probe the magnetic field waveform caused by the spark discharge between spherical metal electrodes.