Tactile feedback of keys can be provided by embossing the top PET layer of the membrane keypad or embedding metal snap domes, polyester domes or forming the graphic layer.  Most membrane keypads will require tactile feedback because the user needs a clear sign that the key was actuated.

The most commonly used tactile feedback by a snap dome is obtained with a stainless steel dome of 2.5N contact force and 7x7mm or 10x10mm dimensions.  APEM offers different shaped snap domes such as oblong or triangular and different forces such as 3.5N or 7N, whichever best fits the application.  The stainless steel snap dome can be gold plated for very low contact resistances.  CuBe domes are used to switch high current levels (120V, 300mA, 2W).

Tactile snap domes provide user with immediate feedback that key is actuated.

General Specifications

1  Graphics overlay Polycarbonate or polyester screen printed on back.

2   Front & rear adhesives Acrylic with or without polyester support.

3  Spacer Acrylic with polyester support.

4  Circuits (upper & lower) Polyester 125 microns. Screen printed conductive inks. Tracks protected by insulating varnish.

5  Protection Polyester 75 microns

6  Stainless steel dome