Metal foil tapes are used for static drain and EMI shielding purposes. Plain smooth copper or aluminium tapes are available with adhesive backing. Tapes with conductive adhesive provides the most effective shielding properties as the layer ensures good electrical contact with the component surface.
A tape with a non conductive adhesive is not as effective as one coated with a conductive adhesive. Where greater electrical contact is required to provide emi shielding (important in the MHz range), the conductive adhesive type should be used.
A copper tape laminated with a high temperature masking tape is also available (ECP 732 HTM) which can be used as an emi shielding tape to provide corrosion resistance on cabinets. The masking tape allows the cabinet to be overpainted for environmental protection, stripping the tape then gives a conductive surface for EMI shielding gaskets to be added.
Copper and aluminium foil tapes are used to shield across the range of frequencies covered by the EMC regulations. They reflect and absorb within the range of frequencies from 200 KHz to over 1 GHz. They are not effective below 200 KHz (magnetic field).