Effects of an electric field shield on the neutralizing characteristics of a corona discharge air ionizer

Abstract

The effects of an electric field shield on the electric field noise and neutralizing current of a corona discharge air ionizer were investigated as a means to prevent soft errors during quality control inspections. The neutralizing current and noise voltage were measured for shielded and nonshielded air ionizers using a charged plate monitor. The use of an electric field shield decreased both the neutralizing current and the noise voltage. Therefore, neutralizing current to noise voltage ratio was calculated to evaluate the effect of the shield on the neutralization performance, and this ratio was several times higher for the shielded air ionizer than for the nonshielded air ionizer.

Effects of Position of an Electric Field Shield on the Neutralization Characteristics of a Corona Discharge Air Ionizer

“…However, the corona ionizers themselves may be a cause of ESD damage and/or soft errors because the high voltage applied to the emitter and the space charge of the ions generated by the ionizers generate high intensity electric field [2]. Therefore, it is proposed to install an electric field shield between the ionizer and the worktable to prevent electrostatic hazard [3].…”

A simulation on neutralization performance of a corona discharge air ionizer by using an equivalent circuit

“…An air ionizer generates positive/negative ions to neutralize the undesired charges. The corona-discharge (CD) air ionizer is the most widely used ionizer in manufacturing and/or inspection processes of electronic devices [11][12][13][14].…”

“…Also, a high density of neutralizing current in the work area ( J W ) is desirable for the air ionizer. In other words, it is required that the ratio J W / E W is high .…”