Holland Membrane manual

Overlay- Top layer of a membrane switch (the graphic interface between device and user) generally made of polyester or polycarbonate.

Pad Emboss- A raised area on an overlay, which defines an entire graphic. (i.e., a full keypad of L.E.D. window.)

Proof- A paper simulation of what a screen printed overlay will look like, submitted to a customer for approval.

Polyester Dome- A keypad on a membrane that has been dome-embossed on the overlay or top circuit layer to add tactile feedback when the switch is activated. The dome shape, which is usually formed by a hydro-forming process, can vary in size and shape to achieve a desired “force” and “tactile feedback” of the keypad.

Prototype Tooling- Method of fabricating prototype components without using steel rule dies (hard tooling) allowing changes before production runs without expensive tooling charges.

Rail Emboss- A raised area on an overlay which defines the perimeter of a graphic. (i.e., perimeter of a keypad or a border.)

Schematic- A drawing showing electrical interconnections and functions of a specific circuit arrangement.

Screen Printing- Method of printing by forcing ink through a mesh selectively. This is done by closing parts of the mesh with a stencil.

Screen Tint- Area of image printed with dots so ink coverage is less than 100%, simulating shading or a lighter color.

Selective Texture- A transparent velvet finish printed on specified areas on an overlay to accentuate design elements such as windows, keypads or graphics.

Shield- A layer of polyester material that is either laminated with aluminum or printed with conductive ink to protect a switch from E.S.D. or E.M.I. interference.

S.M.D.- Surface Mount Device.

S.M.T.- Surface Mount Technology.

Specified Resistance- Maximum allowable resistance measured between two terminations whose internal switch contacts, when held closed, complete a circuit.

Sub-Surface Printing- Imaging on the back (second surface) of an overlay so the printed graphic is protected from wear by the actual material.

Tactile Ratio- A measure of tactile response.

Tactile Response- A sudden collapse or snapback of a membrane switch prior to contact closure or after contact opening.

Tactile Switch- A switch assembly that provides a tactile ratio greater than zero. Tactile switches give the user immediate physical feedback that the switch has been activated. Tactile feedback on a membrane switch can be achieved by using a stainless steel dome or a polydome construction.

Termination- How a switch is connected to the device it activates.

Translucent- Partially transparent. Having the property of diffusing light.

Transparent- Having the property of transmitting light without appreciable scattering so that objects beneath are entirely visible.

23