From early days engineers have been looking for ways to shield circuits from electromagnetic interference (EMI). One of the most effective methods of shielding is by creating an electrically conductive enclosure around the circuit or device. This can be accomplished by using any electrically conductive material. Advances in coated microspheres have enabled the creation of light weight electrically conductive coatings that provide excellent EMI shielding.
Electrically conductive microspheres are produced by applying a metallic silver coating to the surface of the microspheres, thus giving the advantages of a metal particle with the additional properties of the core microsphere.? Typically hollow glass microspheres are silver coated as this offers the combination of a low density filler and a conductive particle. ? Coatings with EMI shielding of greater than 45db have been produced by adding as little as 20% by weight of M-18 silver coated microspheres.
Cospheric offers metal coated (silver)? electrically conductive microspheres in a variety of sizes and densities as shown in the table below, custom particle size ranges are also available:
|Product||Average particle size (?m)||Particle size range (?m)||True particle density (g/cm3)||Bulk density (g/cm3)||Crush strength (psi)|