Switches: A Brief Intro

Chances are that if you were to remove a keycap from your keyboard, you would find that what lies underneath is a small dome made from silicone rubber. One such dome is found under each key. Pressing on a key squashes the rubber dome inside, and this presses together two membrane sheets (through a hole in a sheet in-between), causing electric current to travel through the key. This is then detected by the keyboard controller—a microchip inside the keyboard—and passed to the computer. This design is called "rubber dome over membrane" because it uses a combination of rubber domes and membrane sheets to form a functioning keyboard. This cost-effective method for constructing keyboards goes back decades, and is now used almost exclusively in every desktop and notebook keyboard.

Mechanical keyboards are named so because of their use of mechanical switches in lieu of rubber domes. These switches are made of several moving parts: a hard plastic “stem” contains two metal contacts and a spring underneath. When a key is pressed, the stem pushes the spring down so the two metal contacts connect, registering the key press to the keyboard’s circuitry and therefore to the computer. This design allows users to have a completely different typing experience: a switch can vary in how much force is required to activate it, and can be made to offer tacticle or audible feedback. Furthermore, mechanical switches are built to withstand millions of key presses without wearing out, unlike their rubber dome counterparts.

The most ubiquituos are Cherry MX switches manufactured by Cherry Corporation, a US company that introduced its first switch in 1985. These switches are usually referenced by their physical color, with each color denoting the switch’s handling characteristics: whether it is clicky, whether it is tactile, and how much force is required to actuate the switch, in centi-Newtons (cN) or grams (g). The following introduces a few of the most common Cherry MX switches and their characteristics.

Mechanical switches — Rubber dome switches

Linear Switches

Linear switches have the simplest operation, moving straight up and down without any additional tactile feedback or loud clicking noise. There are two common types of linear switches—Black and Red.

Blacks

Cherry MX Black switches are one of the older Cherry switches. They have a medium to high actuation force, at 60 cN, which means they are the stiffest of the four most common Cherry switches. These switches are used in point-of-sale stations, but typically aren’t considered ideal for typing due to their high weighting. The stronger spring also means that they rebound faster, meaning they can be actuated quite quickly given enough force.

Reds

Cherry MX Red switches were introduced in 2008. They have a low actuation force, at 45 cN—tied with Brown for the lowest of the four most common switches. Red switches have been marketed as a gaming switch, with the light weighting allowing for more rapid actuation, and have become increasingly common in gaming keyboards.

Tactile Switches

Tactile switches provide, as the name suggests, additional tactile feedback as the key actuates. As you press the key down, there is a noticeable bump which lets you know that your key press has been registered.

Browns

The most popular type of tactile, non-clicky switch is the Cherry MX Brown. This switch was introduced in 1994 as a special “ergo soft” switch with an actuation force of 45 cN. Gamers prefer this switch for its light actuation force; they are also ideal for typing in office environments, where a clicky switch might annoy some.

Clears

Clear switches are a stiffer version of Brown switches, with a tactile bump and weighting of 65 cN. They are becoming increasingly rare in many models of mechanical keyboards despite remaining a favorite of typists who prefer a lot of feedback.

Clicky Switches

Clicky switches add a deliberately louder “click” sound to the existing tactile bump. When the actuation point is reached, the slider is propelled to the bottom of the switch and the click noise is produced.

Blues

The Cherry MX Blue is the most common clicky switch, and was first made available in 2007. Blue switches are favored by typists due to their tactile bump and audible click, but can be less suitable for gaming as the weighting is relatively high—50 cN—and it is a bit harder to double tap, as the release point is above the actuation point. Blue switches are noticeably louder than other mechanical switches, which are already louder than rubber domes, so these switches can be a bit disruptive in close working conditions.

Some of this page content was adopted from an article by William Judd on Keyboardco.com

Gif animations were created by Lethal Squirrel on Geekhack.org