Membrane touch switch

A membrane switch comprising;

• a base sheet including a polyethylene glycol terephthalate film having conductive lines on one side of the film, a spacer sheet having one side adhesively secured to the side of the base sheet having the conductive lines, said spacer sheet having a plurality of apertures, each of said apertures being aligned with a selected portion of a selected conductive line, said spacer sheet being a sheet of polyethylene glycol terephthalate film having a thickness of 10 mils, a flexible cover sheet including a polyethylene glycol terephthalate film having a thickness of 2 mils adhesively secured to the other side of the spacer sheet, a second plurality of flexible conductive lines on the side of the flexible cover sheet adjacent to the base sheet, each of said flexible conductive lines having a portion positioned in alignment with a selected aperture, each of the first mentioned conductive lines and the flexible second conductive lines having a pad aligned with each aperture to provide opposing facing pads at each aperture, each of said first mentioned conductive lines and said flexible conductive lines and the respective pads being a layer of vacuum vapor deposited aluminum having a thickness of 0.0025 mil, and an indicator sheet being a polycarbonate film having a thickness of 10 mils and being transparent adhesively secured to the flexible cover sheet, said indicator sheet having indicia on the side of the polycarbonate film adjacent to the flexible cover sheet, said indicia being aligned with respective apertures to indicate appropriate positions for applying a flexing force to the flexible cover sheet, whereby flexing of a selected portion of the cover sheet at a selected aperture toward the base sheet moves that selected portion of the cover sheet and the portion of the flexible conductive line and pad on the selected portion of the flexible cover sheet through the selected aperture into electrical contact with a selected portion of a selected conductive line and respective pad on the base sheet aligned with the selected aperture.

A membrane switch comprising;

• a base sheet including a polyethylene glycol terephthalate film having a plurality of conductive lines on one surface of the film, a spacer sheet having one side adhesively secured to the one surface of the base sheet having the plurality of conductive lines, said spacer sheet having a plurality of apertures, each of said apertures being aligned with a selected portion of a selected conductive line, a flexible cover sheet including a second polyethylene glycol terephthalate film adhesively secured to the other side of the spacer sheet, a second plurality of second conductive lines on the side of the cover sheet adjacent to the base sheet and having selected portions positioned in alignment with selected apertures in the spacer sheet, a pad formed integral with each portion of each of the first mentioned and second conductive lines aligned with a given aperture, forming pads on opposite sides of each aperture, each of the conductive lines and integral pads including a layer of vacuum deposited aluminum on the respective film having a thickness of 0.0025 mil extending over the entire length of each of the conductive lines and each of the pads, a layer of silver having a thickness of one-half mil overlaying and contacting the entire surface of the layer of aluminum, a transparent flexible polycarbonate indicator sheet adhesively secured flexible polycarbonate indicator sheet adhesively secured to the cover sheet on the side opposite the side having the second conductive lines, and indicia on the side of indicator sheet adjacent to the cover sheet, said indicia being aligned with respective apertures in the spacer sheet, whereby application of an appropriate force to a selected indicia on the indicator sheet flexes the indicator sheet and the cover sheet to move the respective pad on the cover sheet through its respective aperture to contact the respective pad on the base sheet on the other side of the aperture to establish silver layer to silver layer electrical contact between said pads.