What Is a Charge Late Analyzer?
A charge late analyzer is an instrument that evaluates the static elimination performance of an ionizer. The performance evaluation of ionizers for the purpose of controlling static electricity and static elimination is specified in the international IEC standard. Charge late analyzer is used to evaluate and monitor static elimination time and ion balance.
The charge late analyzer is supplied with a metal plate of a predetermined size, which is charged, and then the ionizer is activated to measure the decay time of the static charge. The ion balance is evaluated by measuring the electrostatic potential of the electrodes after a certain period with the metal plate uncharged.
Uses of Charge Late Analyzers
The charge late analyzers are mainly used to measure and control the static elimination performance of ionizers. It has the advantage of visually displaying the field strength, charge potential, and decay time of static electricity, which are not visible to the naked eye.
Examples of applications include the detection of discharge in semiconductor and LCD manufacturing equipment, identification of the location of discharge in the manufacturing and mounting processes of electronic components, and evaluation of static elimination products. It is also used to determine malfunctions caused by electrostatic discharges in electronic equipment and to verify anti-electrostatic measures in manufacturing processes. Other applications include measuring the charge decay of tools and determining the antistatic effectiveness of semiconductor storage cases and bags.
Principles of Charge Late Analyzers
An ionizer removes static electricity by generating ions that strike an object. In evaluating the performance of the ionizer, it is important to measure the ion balance, which is the mixing ratio of positive and negative ions. Charge late analyzers, an electrically insulated and uncharged metal plate, is placed in the ions coming out of the ionizer, and the electrostatic potential of the electrode is measured to determine whether the polarity and electrostatic potential are positive or negative and how much they deviate from each other. An ion balance of 0 V is the ideal ionization performance of the ionizer. It is specified that a metal plate 150 mm square per side with a capacitance of 20 pF should be used.
To evaluate the ionizer’s speed of static elimination, the decay time, or the time it takes the ionizer to neutralize the electrostatic charge stored in a charged electrode with a capacitance of 20 pF, is measured with charge late analyzers. Decay time is measured by measuring the time it takes for the potential of the charged metal plate to decay to 10%. A short decay time has a strong static elimination capability, but care must be taken with semiconductors, as they may be destroyed if they are eliminated in a short period by highly concentrated ions.