Wednesday, January 9, 2008

Emi Wire Mesh Shielding

EMI wire mesh shielding is used to protect various circuits and devices from unwanted frequencies or signals that generate attenuation. These are very effective in reducing the effect of these signals. EMI Wire mesh shielding is generally used for joints and seams of electronic enclosures. EMI wire mesh shielding gets wrapped around cables easily and thereby reduces corona discharge in addition to EMI shielding. These EMI wire Mesh have excellent flexibility and conforms easily to complex and irregular surfaces. The mesh is typically a plain weave with either square or rectangular apertures. EMI wire mesh of different materials such as copper and stainless steel are easily available in the market.

The best feature of EMI wire mesh shielding is that these are very light in weight. Most of the EMI wire meshes are available as all mesh together with an elastomer core so as to increase compression characterstics and also increase the deflection range. Different materials have different attenuation potential, mechanical characterstics and corrosion resistance. So while choosing them you should keep your requirements in mind. Standard core materials are available in neoprene, silicone and polyurethane foam. Core material plays a very important role and hence should be selected very carefully. It should be selected keeping in mind temperature, chemical resistance and mechanical characterstics.

These EMI wire mesh shielding is at its best when the compression force is very high. It is directly proportional to the compression force and increases with increasing the force. But the compression which the material can withstand should always be kept in mind. Compressing beyond the materials capability can produce compression set. Here the use of elastomer core increases the compression capability. These days the wire mesh for EMI wire mesh shielding is electroplated, fusing the wires crossover which helps in improving the uniformity and conductivity of the mesh and also reduces surface reflections.