Effective Tips for Choosing the Right Membrane Keypads
When it comes to the Human Machine Interface, membrane keypads play a vital role. They are responsible for the functionality of these machines. Therefore, they need to be of the highest and the finest quality. Unless the HMI has a touch screen, it is most likely to depend upon a keypad.
There are different types of membrane keyboards available. These keypads serve the same purpose, but they do not have the same functionality. The good news is that today, we even have access to the touch keypad membrane.
With a wide variety of keypads, choosing the right one can be a daunting task. Nonetheless, you do not have to worry about it. In the course of this article, we are going to talk about the basic types of keypads and choosing the right one.
Different Types of Keypad Membrane
You have membrane is the most common type of keypad. You will find it in almost all household appliances. In addition, they are part of most commercial applications. A typical membrane consists of 3 basic layers. The top layer, a space layer, and a back layer.
Each of these layers serves a certain purpose. For instance, you notice the key printed at the front and the labels on the top layer. Likewise, the back and the space layers feature conductive stripes. For the HMI or the computer to register keypress, the operator needs to press down the key.
This results in getting both the upper and bottom layers together.
Another interesting and widely popular keypad type is dome-switch. You will find it most in commercial applications. Dome-switch keypads are a combination of mechanical switch keypads and a flat panel membrane.
It features a dome-shaped switch that incorporates silicone keypad with two circuit board traces embedded under it. Since these domes create tactile feedback, therefore they are popular among work-related and commercial applications.
Furthermore, these switches have a high-reliability level. They tend to last for as many as five million cycles.
These keypads greatly differ from other keypads. They use capacitance technology in order to register a keypress. So, when a user presses a key, it results in enabling the capacitance of the capacitor pad. These keypads generally have an aluminum finish. Also, they use foram element keys.
Despite the lack of popularity, capacitive keypads are something a viable choice for a number of applications.
Scissor Switch Keypad
Scissor Switch keypad is another popular type of switches. Its name is self-explanatory. The keypad features keys that look like scissors. Every key has two separate plastic pieces. These pieces are lock together like scissors.
In addition to these scissors like pieces, the switch incorporates dome-like rubber. It is something similar to the dome-switch keypad. However, scissor switches have improved functionality mainly because of the scissor design. The design keeps the keys connected together.
The manufacturer uses multiple ways to create effective scissor-switch keypads, but the most famous is the 3-layer scissor switches. Although scissor switches offer a number of benefits, they do have some downsides.
For instance, scissor switches are inexpensive in comparison to both dome and membrane keypads. In addition, these keypads have the ability to accumulate dirt and debris under the keys. Thus, resulting in a shorter lifespan of the keypad.
Nonetheless, with regular cleaning, you can drastically improve the lifetime of the keypad.
How to Choose a Keypad?
Now that you have an idea of the basic keypad types. Next, you need to know some important factors that would influence your keypad choice. You can go with membrane keypad or capacitive keypads; it all depends upon your requirements.
Silicone Rubber or Mechanical
Depending on the material that a manufacturer uses to create keypads, mechanical and silicone rubber are the two main categories. Most of the keypads fall under one of these two categories. If you want your application to have hard plastic-like keypads, then you should go with mechanical keypads.
On the contrary, for an elastomeric keypad, you need to choose the silicone rubber keypads. These keypads allow flexible and soft construction. It is possible to bend them without breaking them.
There are certain keypads that come with an ultraviolet (UV) coating. We generally call these keypads the UV keypads. These keypads have an additional printing on top of the foil substrate’s top layer. The layer is the UB resin layer.
The manufacturer would add the decorative graphics to the second layer of the foil substrate.
Tactile feedback plays a vital role when choosing perfect membrane keypads. A keypad that completely lacks the tactile feedback is bound to cause type and input errors. Of course, when the user does not recognize any response against the keystroke, he or she is bound to make mistakes.
Tactile feedback, on the other end, helps create a physical sensation against the keystrokes. It gives the user the satisfaction that something has happened. With tactile feedback, after your press the keys, then they pop right back up with moderate force.
In case, there is no tactile feedback, it means you did not press the key all the way down. So, to give the command, you would have to press the key again. A good example of keypads with tactile feedback is your laptop keyboards.
Key height is another important factor that requires consideration. There are certain keypads that have a higher key height in comparison to others. The key height has a direct impact on the tactile feedback of the keypad.
The higher the key, the greater the tactile feedback and vice versa. However, it is important to maintain a certain height. If the keys are very tall, they would be extremely uncomfortable to use.
If you are looking for a keypad for your workplace, we would recommend that you go with a backlighting keypad. Generally, the manufacturers use LED bulbs behind the keys to brighten them up. The light-emitting diodes are perfect to type in the dark.
In addition, the manufacturer often uses them in combination with light guides. With light guides, the light is evenly distributed. Thus, it results in light uniformity and power consumption. Something, everyone wants to have.
Choosing Membrane Keypads for Outdoor Use
When choosing a keypad, you also need to focus on the environmental aspect. Some keypads might perform exceptionally well indoor, however, they fail miserably outdoors. Therefore, to ensure the success of your keypad for outdoor use, you need to consider the following factors.
Durability is another feature that you need to focus on. There is no denying that keypads that are installed outdoor tend to wear down earlier in comparison to keypads that you install indoor. Mainly because outdoor keypads have to face harsh weather conditions.
Something the indoor keypads are safe some. Therefore, when choosing an outdoor membrane keypad make sure that is durable and robust. It should have the strength to withstand outdoor wear and tear.
Water-resistance is among the most important feature, especially for an outdoor keypad. It is imperative for the keypad to have been water-resistant. In case, you are placing the device in the relatively covered area, however, you won’t be able to stop the moisture vapor to get to the surface.
In some cases, it might settle underneath the keys, thus damaging the entire electrical circuits. Fortunately, all membrane keypads, even some touch keypad membrane are water-resistant. The reason being, their design of being embedded into the circuity.
Nonetheless, we should recommend that you double-check the keypad for being water-resistant before installing it outside.
Backlighting is another feature that you should incorporate for your outdoor keypad. Of course, it is an excellent feature for any keypad in general. But in the case of outdoor, it can be really handy especially when the sunsets.
At night, when there is no sunlight, a backlight keypad would make it easier for the consumer to distinguish between buttons. It would ensure typing accuracy. The backlighted membrane keypads offer visibility and ease. It allows the operators to see clearly and avoid any sort of errors.