2002 年 5 巻 6 号 p. 604-608
Surface breakdown phenomenon of printed wiring board was investigated under decreased pressure from 100kPa to lkPa. The experiment was carried out by do pulse voltage with the frequencies in the range of 50Hz to 200Hz. Printed wiring boards of epoxy resin laminate have been employed to investigate the effects of atmospheric pressure and the frequencies of applied voltage on the discharge quantity. The study revealed that the time to breakdown increases with lowering pressure, and it decreases with increasing the frequency of applied voltage. The characteristics of discharge currents under decreased pressures and the frequency were discussed by using power spectral density of discharge current. The results show that the power spectral density of discharge currents decreases at 100Hz, but increases at 200Hz as the atmospheric pressure decreases.