One of the main reasons that people use silicone rubber keypads is because they can feel the buttons depress and return. They know when a feature has been activated by its tactile response, sometimes called the snap force. Feeling the button go down and come back up is part of what gives your customer peace of mind when using your product. Tactile response conveys the feeling that “it works.” It’s something your customers will notice when using a quality silicone rubber keypad instead of a touchscreen or a poorly made offshore rubber keypad.
Feeling the Physics
When designing a new product using a keypad system, it’s always important to consider the snap force. It is a ratio determined by two scientific forces, actuation force and contact force. When the user presses the key momentarily, this is the actuation force. The contact force is the slight pressure which keeps the key down. How much snap force is needed to feel that click and operate the button is critical to the popularity and success of a product using a custom silicone rubber keypad.
Why It Matters
Most products use a 50-percent snap force. Here’s why. If the tactile response on the rubber keypad is too low, the button is very soft. The user can’t feel it and may have doubts if the product is working. This can lead to double activation of keys, which can prevent the machine from doing its job properly. This can also lead to rubber keypad abuse by frustrated and aggressive operators. On the other hand, if the snap force is too high, the key will wear out more quickly, shortening the lifespan of the product. Silicone rubber keypads that carry a moderate ratio are more likely to give the user peace of mind and help your product to function with a longer life.
Lower or Higher Tactile Response
While most situations call for an approximate 50 percent snap force, there are some situations where that varies. A lower tactile response on molded silicone rubber keypads might be preferred when it’s important to have a quieter keyboard. Another scenario might be a tight tolerance, providing minimal space and height for the rubber keypad to operate. In such cases, you don’t have to push the button all the way down to make it work. In other cases, you might want to make it harder to depress the button. Perhaps the key has important consequences and you want to be sure that the user doesn’t strike it by accident, as in operating military keypads or medical rubber molded keypads.
How it feels to depress buttons on a custom keypad can also be adjusted by the type of silicone rubber used. The durometer is the measurement of its hardness. A lower number, such as 40 durometer, is a softer silicone rubber. A higher durometer, such as one around 70, is harder, and therefore more difficult to push.
When trying to decide the best options for a new product’s custom rubber keypad design, the tactile response and force of use are important to how the product is used and how well received it is. SiTECH offers several different options to help you achieve the desired effects for your new product. For more information about the various design specification options for silicone rubber keypad manufacturing through SiTECH, contact our office.