EMI/RFI Protective Envelope for Membrane Switches
Original Publication Date: 1984-Dec-01
Included in the Prior Art Database: 2005-Feb-05
A membrane switch assembly for a keyboard has no inherent EMI (electromagnetic interference) or RFI (radio frequency interference) protection. The EMI/RFI shielding for a membrane switch assembly has been previously provided by mounting the membrane switch assembly on metal base plates and/or applying metallic coatings to the inside of the enclosure for the membrane switch assembly, for example. These metal base plates and/or coatings on the enclosures to obtain adequate shielding are avoided through providing the outer surfaces of a membrane switch assembly with a conductive metal. A membrane switch assembly 1 (Fig. 1) for a keyboard includes three separate layers 2, 3, and 4 of polyester film. The upper layer 2 has switch contacts 5 (Fig.