Dangers of ESD in the cleanroom and possible solutions

The topic of ESD in cleanrooms should not be neglected, as electrostatic charges and discharges can occur in cleanrooms. This poses a particular risk, especially in cleanrooms in which electrostatically sensitive components are produced, assembled or otherwise processed. ESD-compatible cleanrooms are therefore required in the electronics and microelectronics industries, among others.

Cleanrooms as a particular ESD problem

But why is the cleanroom particularly susceptible to electrostatic charges and discharges? The answer: If the air for cleanrooms is filtered, which is done in order to allow as few particles as possible into the cleanroom, this results in less electrostatic equalization of the cleanroom air. This is because air filtration reduces the natural ion content of the air.

In addition, the electrostatic equalization potential of the cleanroom air is reduced by the lower humidity of this air compared to normal air.

The consequences of this special cleanroom environment: charged products in the cleanroom attract residual particles from the air, which leads to contamination of products such as wafers. However, the work surfaces in the cleanroom themselves can also become charged and contaminated by the associated attraction effect, which in turn can lead to product contamination.

In addition to charges, uncontrolled discharges in the cleanroom are also dangerous if they affect electrostatically sensitive components, such as semiconductors and circuit boards, which can be damaged or even destroyed as a result.

Damage to components that is only discovered later in the production process is particularly problematic, i.e. when the defective components have already been assembled with other components, which increases the cost of replacement or repair many times over.

The use of cleanroom gloves can also pose an electrostatic hazard in the cleanroom. This is because the friction between the glove and other objects in the cleanroom can lead to electrostatic charging.

It also poses a risk if production machines are operated by statically charged personnel or come into contact with charged products. Faults in production machines caused by these charges are often classified as software faults, although they are actually ESD faults.

ESD ensures local downgrading of the cleanroom class

Cleanrooms are divided into so-called cleanroom classes, for example according to the ISO classification system. Depending on the maximum permissible number of particles of a certain size per cubic meter of air, a cleanroom belongs to a different cleanroom class. However, if there is a partial attraction of dirt particles due to electrostatic phenomena, there may be a local loss of up to two ISO cleanroom classes in the cleanroom.

Special cleanroom-compliant ESD products

To combat electrostatic charges and uncontrolled discharges in the cleanroom, you can use special furniture, special clothing or special consumables, for example. There are many such cleanroom-compliant ESD products or cleanroom products that are ESD-suitable. In the abovo online store, you can buy the following products, among others, which are suitable for ESD applications as well as certain cleanrooms:

With special ESD cleanroom overshoes, for example, charges caused by friction can be dissipated again.

Please also read our article: Which consumables are suitable for both cleanroom and ESD environments?

Air ionization as a solution?

In addition to the use of special ESD cleanroom products, air ionization can also be used to solve ESD problems in the cleanroom. An air ionizer can be used to neutralize electrostatic charges. This is because air ionization restores or even increases the ion content in the cleanroom air. As soon as a charged surface comes into contact with the ionized air, the electrostatic charge is neutralized.

Air ionizers are also suitable for eliminating errors in production machines that are erroneously classified as software errors but are actually ESD errors. Companies that use robot systems in particular have installed air ionizers. Air ionizers are also used against static charges in the plastics processing industry and the printing industry.

Advice on ESD and cleanrooms

At abovo, we specialize in both ESD and cleanroom products. We can therefore help you to find products that are suitable for both ESD and cleanroom applications.

You can contact our experts conveniently by e-mail or telephone for a no-obligation consultation: