4998790644_be308db6f4_zRubber keypads are found in virtually every setting possible, including hospitals, homes, factories, restaurants and retail businesses. Featuring a soft rubber membrane built over electrical transistors, they are a key component in Human Machine Interfaces (HMI). If you are thinking about ordering some custom rubber keypads, we have some tips to help.

Size Matters

Have you ever attempted to use an HMI in which the rubber keypads were too small to press? This is an all-too-common problem in many HMI settings, and as such, it can reduce the functionality of the HMI. When designing your rubber keypads, make sure the buttons are large enough so that the operator can easily press them. Conventional wisdom should lead you to believe that larger buttons are easier to press; however, you obviously don’t want them to be too large, as this may restrict the total number of buttons that you can use.


Rubber keys should be spaced far enough apart so that the operator doesn’t accidentally press a nearby key. If the keys are placed too close together, the operator may press two or more; thus, triggering unwanted commands. The example photo displayed above reveals keys that are spaced apart in a manner to prevent this from happening.


While not necessary in all applications, backlights can prove useful for illuminating keys so they are easier to be seen. Think about your particular application and how the keys will be used to decide whether or not backlighting is necessary. If you intended to use the keys and HMI at night, for instance, backlighting is recommended. Without some type of illumination, the operator won’t be able to see the keys. But if the keys and HMI will be used during the day — or in an indoor facility — backlighting may not be necessary. Either way, you should decide if your particular application would benefit from the use of backlighting.

Faceplates or No Faceplates?

Including faceplates on your rubber keypads is an excellent way to the protect them from damage. Faceplates act as a barrier of protection between the keys and the outside elements. Whether it’s moisture, dirt, debris, oil, etc., faceplates will block out these elements so your keys remain safe underneath.