Custom Membrane Switches
At its core and most basic function, a membrane switch is a momentary electrical contact on/off switch that activates or de-activates an electric circuit. These are sometimes called single pole, single throw, normally open (SPSTNO) switches. Membrane switches are manufactured by screen printing the circuit directly onto a plastic substrate with silver or carbon conductive ink. The simple, versatile, durable, and economical design of a membrane switch make it a superior alternative to the mechanical switch.
Membrane switches can be constructed with multiple circuit layers, and more elaborate graphic design features, such as domed key embossing. Membrane switch designs that are more complex require more material layers for proper construction and reliable operation.
Membrane switches, when combined with components such as a tactile dome, graphic overlay, or integrated LEDs or resistors can provide the designer with virtually limitless capabilities to create the ideal custom user interface for their products.
Working with Design Mark for Membrane Switches
At Design Mark, the primary core competence is the custom design, engineering, and manufacturing of membrane switches, overlays, and control panels to cater to the unique interface needs of customers.
Design Mark has the expertise in membrane switch design to help make sure your project is completed as efficiently as possible. Design Mark understands the need for a membrane switch that stands up to the harshest of environments and the durability requirements necessary for industrial applications. Design Mark’s experienced engineers, excellent designs, and high quality manufacturing processes assure the reliability of the finished membrane switch components.
Components of a Membrane Switch
A membrane switch typically has the following basic layers:
- Graphic overlay with subsurface printed text/graphics,a polyester or polycarbonate layer with or without embossed keys
- ESD Shielding layer (optional)
- Spacer and/or Dome Retainer
- Polyester printed circuit layer
- Rear adhesive with liner
- Custom printing, logos and graphics
- Surface texture materials
- Custom shapes
- Backlighting (fiber optic or electroluminescent)
- Multiple tactile dome options for tactile feedback or non-tactile option
- EMI / ESD / RFI shielding options (for electro-magnetic interference, electro-static discharge and radio frequency interference shielding)
- Embedded LEDs and/or resistors
- Multiple connector styles
- Normally environmentally sealed to keep incidental dust and moisture out
- Window lens coating
- Many more options are available
Applications for Membrane Switches
Membrane switches are used in many consumer products as well as in many industrial applications.
Some of the most common applications for a membrane switch include:
- Medical equipment
- Industrial control panels
- Household appliances / White goods
- HVAC controls
- Consumer electronics
- Retail equipment
Household appliances like microwave ovens and stoves are typically operated by membrane switches. Vending machines, kiosks, exercise equipment, and gasoline pumps are other common retail/consumer applications. In industry, any manufacturing equipment can have a control panel with a membrane switch. Medical test equipment and HVAC controls are also good examples of uses for membrane switches.
Design Mark offers membrane switches that perform, with long life cycles and high durability. Our membrane switches come in a variety of shapes, sizes and materials, but share these common features and benefits:
- Easy to use interface
- Easy to clean hard surface, resists moisture, abrasions
- Long life at low cost – the average switch life is 500,000 to 5,000,000 actuations
- Reliable, attractive, customized user interface
- Custom design flexibility – match with existing components, graphics, shape, color, branding
- Custom switch features – embedded LED, backlighting
- Short lead times
Membrane Switch Materials
The graphic overlay surface or faceplate material is one of the main considerations in designing a custom membrane switch, with polycarbonate and polyester being the most commonly used materials. Polycarbonate is clearer, easier to fabricate and print but is less durable in constant use. Polyester is more challenging in its manufacturing, but is more durable and has better resistance to environmental conditions. Polycarbonate is slightly less expensive than polyester but the difference is minimal and not usually a major consideration. The choice should be made based on what works best with how and under what conditions the membrane switch will be used. Hard-coated materials are also available to reduce gloss/glare and provide added durability/scratch-resistance and chemical resistance. View the graphic overlay page for detailed information on these materials, or download a copy of Design Mark’s Membrane Switch Design Guide here.
Design Mark’s Design and Manufacturing Process
Design Mark utilizes state of the art equipment to provide customers with an exceptionally streamlined and efficient development process. Design Mark uses established vector-based CAD software programs such as AutoCAD, Adobe Illustrator and CorelDraw. Benefits of working with Design Mark include reduced lead times, higher quality control, and highly competitive costs. Learn more.
Types of Membrane Switches from Design Mark
- Custom membrane switches
- Membrane switch panels
- Membrane keypads
- Membrane switch overlays
- Keypad switches
Membrane Switches Characteristics
Membrane switch products are available in various forms and are capable of providing different feedback levels to the user. Design Mark will use terms like audible, tactile, snap acting dome and poly-dome when discussing the feel and behavior of the switches.
A traditional membrane switch will use a printed polyester “membrane” with a printed layer of conductive silver ink as the circuit and actuation layers. These membrane layers are separated using an adhesive-backed spacer that provides a gap between the upper and lower circuit to keep the switch in an open state. Pressing on the switch location will compress the upper circuit and cause the printed silver contact area to bridge the gap to the lower circuit and close the contact, thereby completing the circuit. When the pressure is released, this compression will release and restore the gap. This type of closure typically will not provide any feedback to the user of the successful completion of the operation other than the event taking place.
In order to provide feedback to the user, the switch designer can employ a physical contact in the form of a plated metal contact disc commonly referred to as a dome. This dome when pressed will “snap” through a centerline and contact the lower circuit which can produce an audible “click” and tactile “thump” under the user’s fingers. This closure action can be felt and often heard providing both tactile and audible feedback to the user on the successful completion of the circuit closure. A designer can also incorporate a thermal-formed polyester switch layer at the contact locations (printed with conductive silver) that are embossed (raised) to form a dome. These “poly-domes” then take on some of the behavior of a snap acting metal dome to provide positive tactile feedback but generally do not provide any audible feedback to the user.
Another available option for the designer is to employ a hybrid design which incorporates a printed circuit board (PCB) as the lower circuit and any combination of membrane, dome or poly-dome employed as the upper circuit.
Membrane Switch Technologies
Membrane switches are designed and manufactured using different technologies and materials depending on the application. These include:
- Tactile membrane switches
- Non-tactile membrane switches
- Metal dome membrane switches
- Poly dome membrane switches
Use Design Marks Secondary Assembly and Value-Added Services
Customers who use Design Mark’s value-added services can:
- Get products to market faster
- Streamline the assembly process
- Boost bottom-line profitability
Learn more about Design Mark’s Secondary Assembly and Value-Added services.
How to Work with Design Mark for Custom Membrane Switches
Design Mark works with customers at various stages of their product development process, from design to prototype to production. Design Mark can offer design and engineering support for early-stage product development or can simply provide a quote for the desired quantities of fully-engineered and ready-to-manufacture membrane switches.
Design Mark recognizes that each project is unique. With over 30 years of experience, Design Mark’s team of engineers and designers is dedicated to bringing expertise, innovation, and quality to each project and finished product.
Membrane Switches with Rubber Keypads
Rubber keypads are sometimes used in conjunction with membrane switches in certain applications. Rubber keypads are manufactured from nontoxic elastic silicone rubber compounds that are typically manufactured using either compression or injection molding. These keypads can then be integrated with switch components, such as printed circuit boards or membrane switches to create a very versatile human to machine interface device. A good example is a modern day television remote control device.
A rubber keypad is a reliable, durable, and economical interface solution in some applications where a key considerations is the keypad’s tactile response and feel. This is the tangible and physical response that you feel when depressing a button or key on a rubber keypad. This tactile feel can be customized to meet the design requirements of the project.
Design Mark is adept at making custom membrane switches with rubber keypads for applications where this is a good fit. Learn more about Design Mark’s keypads offerings.
Request Membrane Switch Design Guide
A free Custom Membrane Switch Design Guide from Design Mark is available for download.
Contact Design Mark for Custom Membrane Switches
Please complete the contact form for further assistance with custom membrane switches and membrane keypad switches from Design Mark.