Membrane Switches

Spacer

The spacer layer of a membrane switch consists of a polyester sheet with pressure sensitive adhesive on both sides that attach to the retainer and circuitry layers. The function of the spacer is to allow room in the switch for the tactile domes to rest without being subjected to partial compression by the layers above the domes. Avoiding this type of pre loading leads to less chance of switch failure and a longer life span for the dome.

The internal cutouts of the spacer are die cut and removed from the sheet of material and the remaining sheet is laminated to the circuitry layer of the switch. Once the domes are installed in the cut out portion of the spacer, the retainer layer or static shield layer is laminated to the top of the spacer.

While this is strictly a utilitarian layer of a switch, spacers are available in different thicknesses that can prove useful in meeting any overall thickness requirements you may have for a switch. Different thicknesses can also allow for the extra space needed when embedded LED’s are utilized in a switch, or when certain domes requiring more height are required to produce the optimal tactile response.

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