Noise Control and Electromagnetic Interference 245
E.3 Enclosure Design
Product enclosure should act as an electromagnetic shield for the noise
radiated by the circuitry within the package. A metal-based, magnetic material
should be used in the enclosure construction. The material should be iron, steel,
nickel, or Mu metal. For plastic enclosures, there are an assortment of con-
ductive paints that can be used to add EMI/RFI shielding to the case. Also, any
vent openings may need magnetic screening covering the openings.
The philosophy of any EMI shield is to encourage eddy currents to flow within
the surfaces, thus dissipating the noise energy. Also, ...