Electromagnetic performance of innovative lightweight shields to reduce radiated emissions from PCBs

An innovative shielding concept to reduce radiated emissions from components and tracks on printed-circuit boards is proposed. The new shield is made of a polycarbonate foil, which is coated by a thin film of nickel (only 50 nm in thickness) and by a 5-/spl mu/m thick layer of tin, and successively thermoformed. The innovative characteristics of such a high-technology shield are the extremely light weight, the high thermoformability, good shielding performance against both far-field and near field sources, low production costs, low installation costs, minimum occupied volume. The mechanical, chemical, and electromagnetic performance of the new shield has been characterized experimentally. Different bonding solutions are tested in order to optimize the shielding performance of the screening cover installed on a conductive ground plane.