The feel of a keyboard is strongly determined by its switch technology. Most of the keyboards use one of the following three concepts:
Membrane / Rubber Dome
If you don’t know which type of keyboard you have, you probably got a membrane keyboard. The keyboards you get for free when buying an All-In-One PC and most of the cheap keyboards are membrane keyboards.
Rubber dome keyboards have a small rubber dome inside of each key. This rubber dome is responsible for actuating the switch and making sure, that the keycap goes back up again. Several membrane sheets underneath the rubber domes are responsible for transmitting the signal (–> membrane keyboard). These two terms actually describe two distinct techniques, but because most keyboards use both, they are frequently interchanged.
Membrane keyboards are very popular, because they are cheap to produce. But there is a big drawback: the keys wear out very fast. After a few years the keys are clattering, they get stuck more often or are harder to press. Often use keys like the space bar or the letter “e” show these effects even earlier and stronger. This irregular wear of different keys is an additional handicap for the user.
The keyboards from Apple and most notebooks and use scissor switches. Scissor switches use rubber domes just like common membrane keyboards, but they have a different mechanic to hold and guide the key cap. Instead of large plastic guide shafts, there are two plastic cross-arms for each key.
Keyboards with the scissor mechanism have a low profile layout and last quite a bit longer than common membrane keyboards (up to 10 – 30 million key presses).
Expansive keyboards usually use mechanical switches. There are several different kinds of mechanical switches, but most of the time, a metal spring gets used for the actuation mechanism. A mechanical switch with a metal spring wears out way slower than one with a rubber dome. But more about the advantages and disadvantages of mechanical switches later.
The German company Cherry dominated the market for mechanical switches for decades. They are still very popular, but by now, there are also a lot of other manufacturers who produce their own mechanical switches (see Switch Types for more information).
The Comparison: Advantages and Disadvantages
Mechanical keyboards have many advantages over rubber dome or scissor switch keyboards. But there are also a few small disadvantages.
Mechanical Keyboard – Advantages
Mechanical keyboards have a significantly longer life span. Most of the mechanical switches are tested for 30 to 70 million key presses. Common membrane keyboards only offer a life span of about 5 million key presses.
No Wear Out
Mechanical switches do not only last longer, they also hardly wear out. Even after several years, typing on a mechanical keyboard almost feels like on the first day. There are no clattering keys or keys getting stuck.
Improved Typing Experience / Feedback
A mechanical switch offers way more tweaking options than a simple rubber dome. So it’s not really surprising, that there are a lot of different switch types with various characteristics.
Some switches have a detectable actuation point, some switches offer additional acoustic feedback. There are switches optimized for gaming and there are switches optimized for typing. More about that can be found in the Switch Types article.
High Stability / Robustness
Mechanical keyboards are significantly more heavy than membrane or scissor keyboards. Therefore, they also have more stability and won’t shift so easy.
Mechanical Keyboards – Disadvantages
Mechanical keyboards are usually a bit louder than other keyboards. If that’s a problem for you, you can either choose one of the silent mechanical keyboard models or use O-Rings to decrease the sound level of your keyboard.
Mechanical keyboards are more expensive than most membrane keyboards. But you should consider it as an investment – if you treat your keyboard well, you won’t need a new one for quite some time.
More weight benefits the stability, but it also makes transporting the keyboard a bit less comfortable. Additionally, the weight can be annoying, if you want to put the keyboard on you lap.