Keyboard Switches Types: A Complete Overview
A mechanical keyboard uses switches under the keycaps. But all switches are not same. Here is a list of different types of switches.
- Rubber Dome Switches
- Metal Dome Switches
- Capacitive Switches
- Scissors Switches
- Butterfly Switches
- Mechanical Switches
- Buckling Switches
- Optical Switches
- Alps Switches
Every type of switch gives a different feel when you use the keyboard. It will have a different tactility and travel when you press it. The force required to register the keystroke will also vary with the keyboard switch type. But beyond the above type of switches, which we will see in detail below, technically, all switches can be categorized into three types – Linear, Tactile, and Clicky. We will see the types of switches from both these perspectives.
Linear, Tactile, and Clicky – What Are They?
This categorization of the switches is based on the behavior of the switch when a key is pressed. Let us see the details below:
These are the simplest switches. They travel linearly when you press them. They feel the same from the point you press the key till the point you release it after the keystroke is registered. These switches do not provide any tactile feedback to the user. Since there is no sound when the key is pressed, users tend to bottom out the keys when using a keyboard with linear switches. This means, the key is pressed all the way down till it can’t go down any further.
As the name suggests, these switches offer a tactile feedback. So, obviously, you don’t end up bottoming out the keys. When the actuation point of the key is reached, you feel a small bump which signals that you can release the key.
Clicky switches let you know that a keystroke is registered by giving out a ‘clicking’ sound. There is a tactile feedback, too and you can feel a bump when the key is pressed. The feedback lets the user know that they can release the key. In this type of switches too, the user does not have to press the key all the way down.
Comparison of the three types of Switches:
|Feedback||No feedback||Tactile feedback (bump)||Sound feedback (clicking) + Tactile feedback (bump)|
|Typing||Slower, because the user bottoms out the key||Faster due to the tactile feedback||Faster due to the feedback|
|Resistance||Consistent||Not consistent||Not consistent|
For obvious reasons, users prefer switches that provide some kind of feedback. Typing becomes easier and more accurate with Tactile or Clicky switches.
Now let us see the other types of keyboard switches based on their function.
Rubber Dome Switches
Rubber Dome Switches are the simplest switch assembly. They are also the most common. They consist of a small rubber dome under each key. The domes are made from a single sheet of rubber and are about 0.6 mm thick. The rubber dome moves down when a key is pressed and actuates the switch so that the keystroke is registered. There are several rubber sheets under the dome. And the actuation is transmitted through these sheets.
Rubber Dome switches are popular because they are cheap to manufacture. However, Rubber dome keys provide very low to no tactile feedback. Also, the switches are prone to rapid wear and tear with use. After a decent period of use, the keys become harder to press. They can often get stuck, too. Also, the keys might start clattering. Keys that are used more often such as the ‘space bar’ or the letter ‘e’, show the signs of deterioration faster than the other keys.
- Feedback: Linear Switches. Low to no tactile feedback.
- Force: More force required
- Travel: More
- Sound: Soundless
Metal Dome Switches
The above image shows a metal dome membrane switches.
The working of the metal dome switches is similar to the rubber dome switches. However, due to the metal dome, the switches provide a tactile feedback when the key is pressed. The dome is made up of pieces of stainless steel. When it is compressed, the user gets a positive tactile feedback. Metal dome switches are not quiet.
Metal dome switches are more reliable compared to the rubber dome switches. They have a life of over 5 million cycles. While stainless steel parts are used, they are often coated with gold, silver, or nickel. When the metal dome is pressed, it connects metal contact is pressed down and connects with another metal contact thus completing the circuit. This is how the keystroke is registered.
- Feedback: Tactile feedback
- Force: Medium
- Travel: Average
- Sound: Sound present
|Feature||Rubber Dome Switch||Metal Dome Switch|
|Feedback||Low tactile feedback or no feedback||Distinct tactile feedback|
|Feel||Mushy feel||Light feel|
The capacitive switches are based on charge detection. When a user touches a key, the capacitive charge from the user’s body is detected by the Capacitive Switch circuit. The capacitive switch assembly consists of two metal plates parallel to each other, known as contact pads. Current is always flowing through the capacitive circuit. However, when the user presses a particular key, one metal plate moves closer to the other.
As the plates move closer, the capacitive reactance between the plates change causing a change in the amount of current flowing through the circuit.
Capacitive keyboards are expensive. However, they are very durable. Brands such as Topre are most well-known for making Capacitive Switches. They use a spring loaded mechanism under a rubber dome. The spring helps with the capacitive action of the switch.
- Feedback: Tactile feedback
- Force: Force varies
- Travel: Medium
- Sound: Quiet
Scissor Switches use rubber domes, too. However, the switch mechanism is different. Instead of relying on a series of rubber sheets to transmit the actuation, they have a scissor-like structure with two sets of plastic crossed arms under each key. The cross-arm mechanism works like the operation of the scissor blades.
The scissor switch has a much shorter travel compared to the regular dome switches. Due to the crisscross arrangement under the key and the shorter travel, the keys have a lower profile. These switches are also quite popular. They are economical, too. Typically, they are found on certain laptops and separate keyboards with a low profile.
The Scissor Switches are generally soundless. However, the keys require more force to press compare to the rubber dome switches. These keys are difficult to clean due to the multiple contact points under the key. Due to the less gap between the keys, debris gets easily stuck between the keys.
- Feedback: Can vary. In some cases, feedback is significant.
- Force: Moderate
- Travel: Short
- Sound: Low sound
The butterfly switches are like scissors switches. However, these switches use a mechanism similar to a butterfly’s wings. The two ‘wings’ are attached to a hinge. The two ‘wings’ or sides are compressed when a key is pressed.
These switches make it possible to have keys with a low profile. Thus, the keyboards look sleek. These are stable switches. The pressure applied by the user is evenly distributed on the surface of the key. Thus, the switches provide more reliability and precision while typing.
Due to the shape of the switches, there is a lot of small space for debris and dirt to get stuck. Also, due to the small parts and difficult-to clean spaces, the debris gets accumulated over time. This can cause the keys to get stuck and difficult to use. This is the main reason why Apple stopped using these switches in their keyboards. Earlier, Apple used these switches in quite a few of their laptops and keyboards.
- Feedback: Tactile feedback
- Force: Less
- Travel: Very Short
- Sound: Quiet
Since butterfly switches are similar to scissors switches, here is a comparison between the two:
|Feature||Scissors Switch||Butterfly Switch|
|Switch parts||Shaped like scissors blades. Overlapping parts.||Shaped like a butterfly’s wings. No overlapping, hinged in the middle.|
|Travel||Short||Shorter than scissors switch|
|Cleaning||Accumulates debris.||Accumulates even more debris and difficult to clean.|
Thus, it can be said that scissors switches are an improvement over the butterfly switches.
Mechanical switches under the keys come in a separate housing. They have a spring mechanism, a stem, and sometimes other moving parts, too. The moving parts are often a tactile leaf or a clickbar for feedback. Mechanical switches are one of the most reliable switches. They are also more durable and rugged. The good quality mechanical switches can have a lifespan of over 50 million clicks. However, they are expensive, too.
The spring provides the resistance and determines the force required to register a keystroke. The actuation point is also determined by the shape of the stem and the design of the housing. The travel of the switch varies according to the design.
Mechanical switches come in all three variants – linear, tactile, and clicky. Usually mechanical switches make a clicking sound. The sound can be decreased by adding rubber dampeners for a quieter experience.
- Feedback: Tactile and/or Sound
- Force: Less
- Travel: Varies
- Sound: Depends on user preference
Buckling switches use a ‘buckling spring’ mechanism on top of the switch. This mechanism provides both tactile and sound feedback. Since the buckle spring moves outwards instead of downwards when the key is pressed, the switch provides a unique tactility. This unique tactile feedback makes them stand out from other switches. There is an auditory feedback, too.
The spring mechanism controls a small hammer-like part. This part strikes an electrical contact. The circuit is thus completed and the keypress is registered.
- Feedback: Tactile and Sound
- Force: Usually medium, varies
- Travel: Long
- Sound: Present
Optical switches have similar parts like regular switches. For example, they too have a stem and spring arrangement like mechanical switches. However, the mechanism which causes these parts to move and function is different in case of optical switches. These switches use an infrared light and photoelectric sensors.
Optical switches have a quicker response time. Since there are no metal parts, these switches are not subject to high wear and tear. Thus, the durable optical switches are quite reliable. Typing is precise in these keyboards. Even when more than one kay is simultaneously pressed during fast typing each keystroke is accurately registered.
The switches are also easy to maintain. They keycaps can be removed for cleaning. Due to no metal contacts and other small parts, cleaning the switches is easy. These switches are especially suited for PC gamers who are looking for reliable keyboards with high precision and responsiveness.
- Feedback: Varies. Some are linear switches, but others could be tactile and/or clicky.
- Force: Low
- Travel: Short
- Sound: Varies
Alps switches were first made by the manufacturer Alps Electric in 1983. However, they have been widely replicated by other manufacturers over the years. And the name ‘Alps’ has stuck for these type of switches.
The original design was that of a linear switch with a cavity to hold and LED. This cavity can also hold the tactile or click leaf to provide the preferred feedback. It has a ‘slider’ that moves between the keycap and the spring. The tactile leaf spring in the switch assembly can be modified to get customized tactility.
- Feedback: Tactile and/or Clicky
- Force: Moderate, Varies.
- Travel: Moderate
- Sound: Varies
Different switches will have different advantages and disadvantages. Comfort, feel, and price are major considerations while choosing switches for your keyboards. If you want to use custom switches and build a keyboard, check out this helpful guide to buy switches and other parts online.