Actuation Force –
The maximum force measured prior to or including the point at which keypad contact closure is achieved.
Backlighting –
A flexible layer within a membrane switch’s construction that illuminates select areas of the overlay, such as text or graphic symbols. Examples of backlighting methods are E.L. (electroluminescent) or fibre optic.
Circuit –
Functioning component (sub layer) of a membrane switch. Typically made of a silver conductive ink printed on polyester. Also can be a flexible copper circuit, a PCB or polyester printed with other conductive materials.
Contact Bounce –
(Make) Point at which specified resistance is achieved.
Dead Front –
Printing translucent ink in an area so that the graphic is visible only when backlit.
Density –
The degree to which light transmits through a colour or transparent window. The higher the density, the less light will be transmitted.
Dielectric Strength –
The voltage that an insulating material can withstand before breakdown occurs, usually expressed as a voltage gradient (such as volts per mil.)
E.M.I. (also R.F.I) –
Electromagnetic Interference (Radio Frequency Interference). Radiated energy from electrical devices, lightning and similar sources which interferes with the proper operation of electronic circuitry.
E.S.D. –
Electrostatic Discharge – transfer of high potential electrical charge between objects by contact or through air.
Files –
Information or documentation created electronically by computer.
Font –
A set of characters having a unified design.
Gloss Level –
The degree of shininess of a particular material, usually specified in percentages such as 75% gloss, 90% gloss, and so forth.
Halftone –
Image made of a pattern of various size and shape dots (newspaper photograph) rather than continuous gray.
Image Setting –
The process by which electronic files are transferred to film or paper directly from the computer (computer onto film technology).
LED –
Light Emitting Diode.
Membrane Switch –
A momentary switching device in which at least one contact is made of a flexible substrate.
Moisture Resistance –
Ability of a material to repel moisture either from air or when subjected to water.
Non Tactile Switch –
A switch assembly that has a tactile ratio equal to zero.
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 colour.
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 aluminium or printed with conductive ink to protect a switch from E.S.D. or E.M.I. interference.
SMD –
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.