Estimation of Gap Breakdown Field in Contact with Hand-Held Metal Piece from Charged Human Body

摘要

Electrostatic discharge (ESD) events due to metal objects electrified with low voltages give a fatal electromagnetic interference to high-tech information equipment. In order to elucidate the mechanism, with a 6-GHz digital oscilloscope, we previously measured the discharge current through a hand-held metal piece from a charged human body, and gave a current calculation model. In this study, we proposed a method for estimating a gap breakdown field in contact with a hand-held metal piece from a charged human body. 40-times measurements of the discharge currents were made for two charge voltages of 300 V and 600 V, and the gap breakdown fields were derived for each measurement. As a result, we found that estimated spark length and gap breakdown field at a charge voltage of 300 V agree with the results derived from the Paschen's law. For a charge voltage of 600 V, however, the estimated spark length is slightly higher than the result obtained by Kawamata, et al. with their different setup for an air discharge experiment but lower compared to the result from the Paschen's law.