Electromagnetic Interference EMI Shielding and Grounding

Both conductive paste adhesives and pressure-sensitive tapes are widely used for EMI protection. Two-part epoxies or one-part silicones filled with silver or silver-plated copper particles are widely used as paste adhesives while acrylic conductive and nonconductive adhesives on aluminum or copper foil are used as pressure-sensitive tapes. EMI shielding tapes are suitable fortemperatures ranging from -40°Cto 121°C and are available in thicknesses from 1.5 mil to 5 miLl Shielding effectiveness is measured as attenuation in dB at several frequencies, for example, from 1 MHz to 20 GHz. Values for several ARclad shielding tapes are given in Table 5.13. 

The electromagnetic shielding effectiveness of a nickel-graphite filled silicone gasket with and without an EMI adhesive, measured over a wide frequency range, is shown in Fig. 5.20.1 1 Test methods and requirements for the control of EMI may be found in MIL-STD-461.t  

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