Posted 20 Feb 2023 10:01 | 1,299 views

Ionization is one of the best methods of removing charges from insulators and isolated conductors. As a result, ionization plays an important role in controlling ESD.

WHEN IS IONIZATION NEEDED ?

Why Ionization?

Ionization is one of the best methods of removing charges from insulators and isolated conductors. As a result, ionization plays an important role in controlling ESD.

An ionizer floods the air with positive and negative ions to remove static charges on process required insulators and non-grounded (isolated) conductors.

Compressed air ionizers can also be used to combat electrostatic attraction (ESA), neutralizing charges on surfaces and particles that otherwise cause contamination or visual defects on products.

Note: An ionizer is a secondary form of defence and does not eliminate the need for standard ESD control devices such as wrist straps, heel grounders and worksurface mats. It is only one element in an effective ESD program.

What is a "Process Necessary Insulator" ?

Insulators are materials where:

_• Electrical current does not flow easily
• Materials cannot be grounded

If the insulator cannot be replaced with an ESD safe alternative then it is considered a process necessary insulator.

Common process necessary insulators: PCB substrate, Plastic connector bodies/cap plugs, enclosures, plastic cases, and some types of glass.

What is an "Isolated Conductor"?

Conductors are materials where:

• Electrical current flows easily
• Materials can be grounded

A conductor that is not grounded or equipotentially bonded is an isolated conductor.

Common Isolated Conductors: Ungrounded components, floating metallic parts in process equipment, or floating cables.

What is Electrostatic Attraction?

Per the article Controlling electrostatic contamination in cleanroom manufacturing “Electrostatic attraction (ESA) increases contamination of critical product and equipment surfaces, causing defects and increasing maintenance costs… ESA attracts and holds particles that would otherwise remain airborne”.

If standard compressed air is used to try and blow contamination and visual imperfections away it will simply charge up the surface and particles will be attracted back. Using ionized compressed air will prevent this by neutralizing the surface in question.

Source: staticcontrol.descoindustries.com
#scs #smp #lonization #esd