ESD coatings
Frequently Asked Questions
The following questions are quite frequently asked:
The answers should help you to get some first information at any time, but please do not hesitate to ask us directly
for further or supplementary information.
We are looking forward to the dialogue with you!
FAQ - frequently asked questions
ESD is the abbreviation for "electrostatic discharge" and describes the equalisation of electrical charges between two unevenly charged materials. For example, this can be electrical shocks, when you touch a vehicle while you are getting out of it or lightenings.
When two objects, being charged either positive or negative, are rubbed against each other and then separated, a difference of electrical potential is created.
When two different potentials get approached, these charges suddenly flow from one object to the other.
Even the human body can be charged by walking and can keep this charge until discharge occurs trough touching an object.
These discharges usually are harmless for humans, but the situation is different for example in the case of electronics assemblies, where electrostatic discharge can lead to failure of components, repair costs etc.
Electronics assemblies are very vulnerable to damages caused by ESD, which can occur anywhere and at any time. Even tiny discharges act similarly to a lightning.
Such discharges can't be seen, heard or felt by humans, but are still able to destroy or to weaken components in a way that, due to a latent error, failures occur only after some time, when the device is already operating.
Especially this poses a serious danger; the repair costs of such errors often are much greater than those of precautionairy protection.
There are measures matched to the requirements, particularly for production, handling, storage and shipping.
At this point we want to refer especially to our ability to coat nearly every surface with a high-ohm conductive lacquer, which makes the charges flow off slowly.
Nearly all enlosures of the series GH02 are available in a standard ESD version.
Generally both questions can be answered positively, even though it is always necessary to regard the complete system:
About EMC (Electromagnetic Compatibility):
This normally is achieved, because contact surfaces are "electrically conductive chromated". In this way, a permanent good shielding against electric fields is created, because the chromate conversion coating prevents a climate-induced tarnishing (corrosion) of the conductive layer. The attenuation can be further improved by using contact springs/EMC gaskets. Regarding painted or powder-coated surfaces we distinguish, whether the back side is "unpainted" (spray mist/wrap-around permitted) or "free of lacquer" (no spray mist/wrap-around permitted). To enable to keep the contact surfaces cost-effectively free, we fall back on our own tool/device construction and the more than 40 years old experience with cover templates.
About ESD (Electrostatic Discharge):
In this case the shield consists normally of a varnish layer, which is equipped with high-ohm conductive pigments.
Make use of our experience!
The implementation of EMC and/or ESD measures is an option, which is performed on customer's request. In case of doubt we advise you to make us produce two prototypes with and without EMC/ESD measures, so that you are able to judge the suitability or the necessarity of the measures for series application at the CE acceptance test of the complete device. In addition to that, we can send you on request our customer information "KDI000010 CE marking of foil keyboards".
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