Abstract: An electronic device such as a portable computer is shielded against electromagnetic interference using a flexible envelope that surrounds a circuit card within the housing of the device. The flexible envelope forms a shielding enclosure and has an electrically insulating flexible sheet, for example of polyethylene, and a sheet of conductive fibers embedded in the flexible sheet so as to leave a nonconductive face oriented toward the circuit card. The conductive fibers can be metallized nylon and are sufficiently dense to obtain a resistivity of 10.sup.-1 to 10.sup.-2 .OMEGA./.quadrature.. The enclosure forms a hollow envelope with the conductive fibers coupled electrically across a seam, for example by cutting the flexible sheet and embedded fibers using heat. For use with a portable computer having a pivoting screen, a neck extension of the enclosure carries conductors through the area of the pivot.

Abstract: A shield blocks passage of electromagnetic energy through a seam of indefinite length between conductive elements and is adhesively attached to at least one of the elements. A preferably non-conductive adhesive is disposed on a conductive surface of a seal in a discontinuous pattern along the length of the seam, defining area of 5-40% adhesive for physically attaching the conductive surface, separated by 60-95% exposed areas for direct electrical contact. The seal can include a compressible body or can be defined by a conductive sheet, for example a fabric provided with a plating or other conductive coating. The areas of adhesive preferably define longitudinally non-overlapping inclined lines extending laterally across the seam. A release liner can removably attach to the adhesive. In a preferred embodiment the conductive surface is the surface of a compressible seal body, such as a conductive sheath on a compressible core.