Today's marketplace sets high demands for fast, accurate, and reliable human-machine interface solutions. It is critical to provide your customers with ease of use, satisfactory tactile response, and rapid functionality when developing your specific application.
Membrane switches are designed to meet a very specific set of criteria depending on the application. Effective membrane switch design requires a good understanding of the application and the ability to communicate what is required for a successful and efficient design.
The purpose of this design guide is to outline the requirements and their role in the membrane switch design process. Using these guidelines will help maximize the quality, reliability, and efficiency of the membrane switch. Cubbison Company is capable of providing custom membrane switch design assistance to meet all of your requirements.
In general terms there are two types of membrane switches, tactile and non-tactile, and both of these can be constructed with or without a graphic overlay. Tactile switches use a metal dome or poly dome to provide a physical “snap” feedback response to the user’s finger, letting him/her know that the button has been depressed. Non-tactile switches do not incorporate a metal or poly dome into the construction and therefore do not provide feedback to the user’s finger when a pushbutton is depressed.
A typical membrane switch construction consists of the following layers:
Dome Retainer (or a Top Circuit for Matrix Circuit Configuration)
Dome Spacer (for use with metal domes)
Other design constructions are available. For further information, contact the Cubbison Company.
Circuitry is designed using either a common bus or a matrix configuration, or a combination of the two. The connection from the membrane switch to the PCB can be made one of three ways.
The tail termination pitch can be 2.54mm, 1.27mm, 1.00mm, or 0.5mm. Metal tines are used for electrical connections.
Cubbison employs a full service art department. If you do not have artwork, Cubbison offers complete membrane switch design services. One of our design engineers will work with you on designing and building a membrane switch custom for your application. Cubbison can also help you select the best printing option available for your intended printed electronics application. Our printing technologies include: screen printing, digital printing, or a combination of screen and digital printing.
Cubbison offers a range of hard coated and textured polyester and polycarbonate films. These substrates have been designed specifically for the graphic overlay film on membrane switches, and range in finish from high gloss to velvet matte. Both product ranges are screen printable on the second surface; they are solvent, chemical and scratch resistant on the first surface. Polyester is the most popular choice as it is more robust, providing superior chemical resistance and allowing for up to 5 million actuations over its lifetime, as opposed to polycarbonate, which is only rated for up to 100,000 actuations. ***For further information on this please contact the Cubbison Company.
The Pantone Matching System (www.pantone.com) is the most popular for graphic art applications. Cubbison has the ability to match Pantone, custom, and transparent colors with our digital presses. There are separate matching criteria for both opaque and transparent colors.
It is important to remember that matching screen printed overlay colors to surrounding components is difficult. For this reason, we are using state-of-the-art color matching equipment in the X-rite Ci7600 spectrophotometer. As long as we have a control color to match against, we can achieve a color match under 1.0 delta in the CIE Lab color space. We are capable of matching Pantone colors, custom colors, as well as transparent colors for windows. We also have the capabilities to do transmission and density readings.
Cubbison can provide either pillow (pad) or rim (perimeter) key tactile designs into polyester or polycarbonate overlays. This process requires a male/ female die set. Overlay embossing dies are manufactured with sophisticated tolerances to allow for material flow.
Our Cubbison design staff will precision-calculate a die for your application.
Display windows are typically transparent and they can be either clear or color tinted. LED windows can be either transparent(with or without color added) or translucent. A transparent color is optically clear and used to filter backlight displays. The transparent color reduces the "blooming effect" of the display. A translucent color is normally used for diffusing an indicator light or backlighting for printed graphics, such as an instrument cluster that is backlit.
Cubbison offers hard coat films that are ideal for membrane switch overlay applications. These films are polycarbonate and polyester substrates that have been specially treated so that their surfaces can be selectively textured, embossed or printed with UV inks. Available in finishes ranging from glossy clear to textured matte black; hard coat films offer a range of display options.
Hard coat films resist scratching and staining from a broad spectrum of foods, household cleaners and aggressive chemicals. For special applications, such as medical equipment, our hard coat films may be embossed or otherwise thermoformed without sacrificing performance characteristics.
Cubbison can print inks specifically designed to give a decorative texture effect on first surface polyester or polycarbonate used for membrane overlay applications. Cubbison offers many, state of the art forms of texture coats from very fine to course. We can custom match your texture. With the new technologies in UV inks we can provide a texture coat that is very durable and will withstand marring.
Circuitry is designed using either a common bus or matrix configuration, or a combination of the two. The connection from the membrane switch to the PCB is made via a cable interconnect, or “tail” that is terminated with either bare contacts or a plastic connector housing (solder tabs can also be used). The tail termination pitch can be 2.54mm, 1.27mm, 1.00mm or 0.5mm. The tail can exit from either an edge or inset location of the part, but not from the button area. Cubbison can supply a range of heat stabilized polyester films which offer high stability specification and are designed to be screen printed with conductive silver and/or carbon, graphite and dielectric inks.
Cubbison provides 3 types of backlighting:
Cubbison offers 4 legged and oblong style domes, see below for the typical characteristics of each:
Cubbison is tooled for Nicomatic and Amphenol FCI (Berg) plastic connector housings.
When a switch is deflected there needs to be a small track designed into the switch for the displaced air to move. The tract will connect all of the switch keys so that air can be displaced. Venting is done internally, and using this design technique allows the switch to remain sealed. External venting is not recommended.
Cubbison can offer aluminum, polycarbonate and acrylic material options for a rigid subpanel. Cubbison can laser fabricate a subpanel to your specifications. It is usually advisable for the subpanel to be slightly smaller than the membrane switch. Conversely the holes and cutouts should be slightly larger than those on the membrane in order to conceal the sub panel.
This design feature can be used for added protection of the membrane switch against environmental factors such as dirt and moisture.
Greater than 1,000,000 Actuations
6 oz. to 18 oz.
0.010" to 0.030"
1 to 10 milliseconds
Circuit Resistance (On)
Circuit Resistance (Off)
20mA at 30 Volts DC
100 Ohms or Less
50 Volts DC (max.)
1.5 Watts (max.)
SPST Normally Open
-40 to +80 Degrees Celsius
-30 to +70 Degrees Celsius