With all of the uses for electronics that contain membrane switches, it is possible that they will be exposed to water or even to liquid solvents. Product failure is not an option when it comes to the environments that require waterproof membrane switches, such as medical, military, harsh industrial, transportation, and material handing environments. To avoid disaster, it is crucial for the electronic components to be sealed so that they are protected. With the proper design and use of adhesives, rubber membrane switches can be waterproof.
Rubber Membrane Switches: The Basics
Rubber membrane switches use compression-molded silicone rubber with conductive carbon pills or with non-conductive rubber actuators. They are known for their exceptional resistance to extreme temperatures and aging. Relatively speaking, rubber keypads are inexpensive when it comes to a per piece basis, but they do require fairly expensive tooling; therefore, rubber membrane switches are the design choice for higher volume projects.
Silicone rubber keypad switches have quite a few features:
- Work as conductive shorting device for Silver Flex membrane switches, PCB membrane switches, and Copper Flex membrane switches
- Can utilize carbon pills, non-conductive rubber actuators, or stainless steel tactile domes
- More keypad travel and a completely different feel than traditional tactile membrane switches
- Customizable actuation forces and switch travel
- Unusual keypad shapes and sizes can be used
- Multiple colors through flow molding the color during the compression molding process
- Rubber keypad top graphics can be further customized by screenprinting
- Rubber keypad switches can be spray coated for enhanced durability
- Rubber membrane switches have excellent abilities to withstand outdoor use
- Can be designed to seal the keypad assembly from moisture and contaminants
- Silicone rubber is resistant to chemicals and moisture
- Laser etching the rubber keypads can allow for backlighting individual keypads
- Fiber optic backlighting
- EL (Electroluminescent) backlighting
Considerations for Waterproof Rubber Membrane Switches
Obviously, marine and outdoor environments require waterproof rubber membrane switches. Another environment that requires a waterproof rubber membrane switch is the medical and healthcare environment, such as in laboratories, hospitals, and clinics, plus those found in physician and paramedical environments. Membrane switch designers and engineers understand the challenges posed by those environments and design waterproof rubber membrane switches with seals that ensure fast, easy disinfecting no matter the harshness of the chemicals or bleaches used. They also design to allow for waterproofing that can withstand frequent pressure washes or frequent on-site wipe downs and spray downs.
Options for Waterproofing Rubber Membrane Switches
One challenge in making a completely waterproof membrane switch is the fact that the switches themselves are limited by the adhesives used in construction; the limitations arise because the adhesives are pressure sensitive. Without using some sort of an external sealing method, adhesives will be water resistant but not entirely waterproof. To construct a completely waterproof membrane switch, keypad assemblies containing graphic overlays require an edge gasket between the overlay edge and mounting case. Another option is to replace the graphic overlay with a molded silicone rubber boot and seal it on the front surface and edges to create a completely waterproof seal.
Qualities of Waterproof Rubber Membrane Switches
For a rubber membrane switch to be waterproof, it should have certain qualities to ensure its functionality and reliability. Those qualities include, but are not limited to:
- Watertight to prevent moisture damage
- Specific materials used that prevent deterioration caused by UV and weather exposure
- Simple to install or retrofit into existing equipment
- Durable enough for years of use
- Custom designs to fit the usage application
- Water resistance from drops of water to full submersion
- Normal operation even after exposure to water
- Free from operating issues even after exposure to outdoor elements
- Simplified waterproof structure employing printed seals and double-sided adhesive sheets
- Circuits isolated from outside environments
Waterproof Rubber Keypads
Another component that should be considered when constructing waterproof rubber membrane switches are waterproof rubber keypads. These ensure a complete waterproof product. When choosing a waterproof rubber keypad, keep these qualities in mind:
- Weather resistant for outdoor use
- User-friendly interface for simple operation
- Durable construction for repeatedly reliable use
- Custom digital printing on graphic overlays
- Easy installation and retrofitting capabilities for use with existing equipment
- Custom designs to meet users’ needs
Design Does Not Suffer with Waterproof Rubber Membrane Switches
You do not have to compromise usability or aesthetic appeal, just because you require a waterproof rubber membrane switch. Rubber membrane switch designers and engineers create products of any size, shape, and color finish even when designing for waterproof switches. The completed waterproof rubber membrane switches are sealed and easy to clean, plus they are dustproof and resist climate, chemical, and mechanical stresses.
The rubber membrane switches typically also are lightweight and have a low-profile that allows for integration into smaller and thinner packages that include hand-held applications. The waterproofing of the rubber membrane switch considerably prolongs the lifecycle of the switch. Leading membrane switch manufacturers offer practical, cost-effective design solutions to fit your product requirements and specifications.
Looking for membrane switch product samples or would you like to set up a free design consultation? You can call us directly by phone (216) 475-6704 or email Customer_Service@Pannam.com