Ground plane shield

Abstract

A laminated groundplane structure for shielding electrical equipment such as printed circuit boards has a conductive sheet sandwiched between a soft foam layer and a rigid foam layer. A connection pin coupled to the printed circuit board or the like pierces the soft foam layer to engage in the conductive sheet. The groundplane can include, in order, laminated layers of soft closed cell foam, an insulating dielectric layer, a conductive fabric defining the conductive sheet, and a relatively rigid foam for maintaining a shape in the groundplane structure. The connection pin includes a conductive post protruding toward the groundplane, and a movable conductive shaft which is spring biased to protrude axially relative to the conductive post for piercing the conductive sheet through the soft foam layer The movable shaft resembles a twist drill with an enlarged or barbed head, which passes through the conductive sheet to engage in filaments of the conductive sheet. The conductive shaft is helically fluted over at least a part of its length engaging the filaments of the conductive sheet. The arrangement is particularly useful in mounting circuit cards in conductive housings of equipment subject to vibration, for example automobiles, because the groundplane structure resiliently cradles the circuit card while the connection pin bites into the conductive sheet due to engagement of the barbed head, the fluted shaft and the filaments of the sheet.