WHY USE EMI/RFI SHIELDING COATINGS?
The ideal enclosure
for electromagnetic shielding would be a seamless sphere
manufactured from highly conductive material, such as copper,
silver, or Nickel. Unfortunately, this solution is impractical
and would render other functions of the enclosure useless.
In the real world (the world of plastics), any enclosure
designed in metal may be impractical and cost prohibitive.
Often the cost constraints or even the shape required of
an enclosure dictates use of plastic injection molded parts.
Most plastic, however, is virtually transparent to EMI/RFI.
For this reason, coatings have been developed to add shielding
characteristics to plastic enclosures. These conductive
coatings reflect the interfering radiation. Some common
shielding coating materials are silver, copper, nickel and
graphite.