Conductive Coatings for EMI Shielding

Posted: 06/08/2018

High performance Conductive Coatings for EMI Shielding

As plastic enclosures offer no protection from electromagnetic or radio frequency interference, the inner surfaces of the enclosure are often coated with conductive coatings for EMI Shielding. Pigmented with highly conductive fillers the coatings offer effective EMI shielding over a broad frequency range.


Silver Copper Conductive Coating for EMI Shielding

Enclosure coated with Silver Copper Conductive Coating for EMI Shielding

Comparison of Conductive Coating Pigments

Carbon offers low frequency EMI shielding.  For that reason carbon conductive coating is used in applications such as metal detectors, for shielding musical instruments or grounding applications.

Similarly Nickel gives a good EMI shielding performance but also gives excellent corrosion resistance. As a result, nickel conductive coating is suitable for marine environments, and is a good choice for shielding plastic enclosures or satellite dishes.

Silver Coated Copper offers superior EMI shielding at higher frequencies, therefore it is a  popular choice for conductive coating of enclosures.  Silver coated copper may also be used to undercoat in electroplating applications.

Finally, Silver conductive coating provides the highest EMI shielding and corrosion resistance, and for that reason is suitable for harsh marine environments.


Performance of Conductive Coating Bases

Conductive coatings for EMI Shielding are available in 3 chemistries, Acrylic, Water Based Urethane and Epoxy.

Acrylic conductive coatings are widely used on electronic enclosures, satellite dishes and board level applications. Easy to apply they bond well to many surfaces. Acrylics are an easy to use solvent based system and do not require heat cure. They also do not contain xylene or toluene. Having strong adhesion to acrylic, ABS, polycarbonate and other injection moulded plastics, the coatings provide a smooth, long lasting and abrasion resistant conductive coating. Acrylic coatings are commonly used on electronic enclosures, medical equipment, drones and communication devices.

Water based conductive urethanes have low volatile organic compounds, and because of that are the only choice for architectural applications. They also have no harmful vapours, are non-flammable with no heat cure necessary. Conductive coatings bond well to plastics, wood, metal and ceramics, as well as to drywall which can be painted over with common latex paints. They also may be used on ceilings, walls and doors to protect rooms containing sensitive electronic equipment such as surgical rooms, recording studios, and server rooms. Furthermore, they also protect from interference from mobile phones, CB, TV, AM and FM signals.

Epoxy conductive coatings are a two part system and cure in 24 hours at room temperature. When cured the coatings are smooth and extremely hard. As a result epoxies are mar and scratch resistant with strong chemical, abrasion and impact resistance. They also give strong adhesion to chemically resistant plastics and other difficult to bond to materials. Epoxy coatings are particularly suitable to military, aerospace, automotive and oil and gas industries, and can also be used on aluminium flanges.


Conductive Pens

Conductive acrylic pens are ideal for repairing or making conductive traces on printed circuit boards, or by the hobbyist. The pens dispense acrylic lacquer pigmented with carbon, nickel or silver flake and are designed for use on smooth, hard and flat surfaces.


Conductive Coatings for EMI Shielding Pens

Drawing traces with Conductive Coating for EMI Shielding Pens

For more information please download our Conductive Coatings catalogue.

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