Moulded plastic enclosures have one specific shortcoming: by virtue of the intrinsic properties of the material itself, they offer no inherent attenuation to radiated fields. In many applications this is of no consequence, but where the enclosed electronics emit interference, or are susceptible to external fields, it is critical. To give our customers freedom of choice on the enclosure while still meeting EMC requirements, Vero Technologies applies conductive EMC plastic coating to the inside of any of our plastic enclosures, turning a standard ABS case into a screened plastic enclosure.
Working with our coating partners, we offer three conductive spray coatings that suit more than 95% of applications, balanced between attenuation and cost. Other coatings are available for highly specialised uses.
All three coatings are COSHH, RoHS and REACH compliant and have passed temperature-ageing and humidity testing with no degradation in attenuation.
A coating is only as effective as the enclosure design around it. When we coat a case we also look at the details that keep the screen continuous: tongue-and-groove joints between the mating halves so there are no long slots to act as antennas, conductive gaskets or interference-fit slots for removable end panels, and the smallest possible cable entry where a battery compartment is partitioned from the electronics. Where a display is required we can apply a clear conductive coating to the window material, preserving screening without obscuring the display.
Graphite or carbon-based conductive coatings minimise electrostatic discharge damage to sensitive components. For the outside of the case we can also apply specialist finishes: anti-bacterial coatings for medical equipment, fire-retardant low-smoke coatings for aerospace, chemical-resistant coatings for petrochemical and pharmaceutical environments, and low-friction or high-visibility finishes for safety-critical applications.
Any of our plastic enclosures, from handheld Veronex cases to desktop instrument housings, can be supplied with an internal conductive coating, and we can combine coating with CNC machining and printing through our enclosure modification service so the case arrives ready to fit. If natural metal screening suits the project better, see our aluminium enclosures.
For the full technical background, including test data and design guidance, read our article on EMC coating finishes for moulded enclosures, or find out more about us.
Nickel typically gives 60–65 dB at 50 microns; copper performs significantly better at high frequency, tested to around 78 dB at 10 GHz; silver gives the highest attenuation of the three.
Yes – the nickel, copper and silver coatings are all COSHH, RoHS and REACH compliant.
Yes. A clear conductive coating can be applied to the window material so the screen stays continuous without a wire mesh obscuring the display.
To discuss an EMC screened plastic enclosure for your project, call +44 (0)1489 776931 or email sales@verotl.com.
