Improving Membrane Switch Durability with Electro Conductive Paint

 

Customer Challenge:

Electro conductive paint is a specially formulated type of paint that incorporates conductive metal fillers into the polymer binder system in much the same way that pigments are added to colour conventional paints. These products improve the conductivity of the surfaces they are applied to and provide a cost-effective alternative to other methods of repairing electrical contacts. A membrane switch is a good example of an electrical contact where conductive ink is used to repair the contact area quickly and inexpensively, ensuring that the contact is both sufficiently conductive and corrosion resistant. These types of switches are used in the design of musical instruments such as organs and electrical drums; however, the switches tend to wear and fail over time from the stress of constant compression. For one MG customer, our challenge was to find an electrically conductive coating that adhered well to metal, was corrosion resistant, and could withstand repeated mechanical compression from a hi-hat pedal without fracturing.

Key Customer Requirements

1. High electrical conductivity
2. Smooth finish that can be machined after application
3. Corrosion resistance film
4. Mechanically tough, able to withstand millions of compressions during product’s life cycle

Solution

MG Chemicals’ 842UR is a 1-part, electrically conductive coating that adheres to a wide variety of substrates. It uses a specially engineered silver flake with a high aspect ratio (high surface area relative to thickness) to help achieve a very smooth cured film that can be applied very thinly (about 8 microns). The customer was able to apply a thin film to the contact surface of the membrane switch, creating a smooth, conductive film and negating the need for more expensive and time-consuming solutions, such as nickel or gold plating.

Conclusion

Electro conductive paint is an easy way to repair worn electrical contacts. This coating provides a highly conductive, durable surface, which ensures the long-term reliability of the circuit. 842UR creates a very thin film with sufficient elasticity to withstand the constant compressive forces required by membrane switches on electrical instruments to function.