1. Different Types of Slim Keyboards
When it comes to mechanical keyboards, people mostly think of them as chunky and heavy, the only thin keyboard that may come to mind is the membrane keyboard. Actually, a new kind of slim mechanical keyboard has recently emerged, the low profile mechanical keyboard.
1.1 Membrane Keyboard
A membrane keyboard is a keyboard whose switches are not separate, moving parts but are pressure pads that have only outlines and symbols printed on them. It works by electrical contact between the keyboard surface and the underlying circuits when keycaps are pressed. There are 2 different types: a flat membrane keyboard and dome switch membrane keyboard. However, they are often cheap as they are made with common materials and matured technology.
image via Logitech.com
1.2 Low Profile Mechanical Keyboard
A low profile mechanical keyboard is essentially a mechanical keyboard with thinner switches, keycaps, and casing. Unlike membrane keyboards, low profile mechanical keyboards utilize individual switches, each key has its own unique response pattern to physical manipulation.
2. The Difference Between Them
2.1 Structure
Membrane keyboards are typically characterized by three layers.
The top and bottom layers are pressure pads, these pressure pads are made of thin, flexible rubber or plastic membrane with printed conductive traces.
The center layer is a "spacer" containing holes wherever a "switch" exists. It keeps the other two layers separated.
Membrane keyboard layers
image via deskthority.net
A low profile mechanical keyboard usually contains low profile keycaps and mechanical switches, PCB, and a case.
Each key has an individual switch. There are three main types of mechanical switches: linear, tactile, and clicky, varying in tactility, actuation force, and sound level. Each variety provides a different typing experience. PCB is a printed circuit board with a hot-swappable option.
Keychron low profile S1 layers
2.2 Mechanism
For a membrane keyboard, when you press a key, the top layer moves toward the bottom layer until they touch. The conductive traces painted on the 2 layers allow the current to flow and then the device registers a keystroke.
Membrane keyboard switch
image via digitalworld839.com
For a low profile mechanical keyboard, when you press a key, the stem moves down to push the spring, which forces two different conductive materials to contact. The current signal is transmitted to the PCB and then the PCB sends signals to the computer.
Low profile mechanical switch
image via cherrymx.de
3. Low Profile Mechanical vs Membrane Keyboard
| Low profile mechanical keyboard | Membrane keyboard | |
|---|---|---|
| Replaceable switch | Yes | No |
| Replaceable keycap | Yes | No |
| QMK/VIA support | Yes | No |
| NKRO support | Yes | Very few keyboards support, mostly support 3/4-KRO |
| Switch lifespan | 50-100 million keypresses | 10-20 million keypresses |
4. Advantages of Low Profile Mechanical Keyboards
4.1 Switch
Low profile mechanical switches give better feedback as you can really feel the actuation point, making the typing snappier with each key press. You can choose from different variants according to personal preferences, whereas membrane keyboard switches are softer and feel little or no tactile feedback. Also, you don't have too many choices when it comes to membrane keyboard switches.
4.2 Keycap
Low profile mechanical keyboards have removable keycaps with a wide variety of low profile keycaps available on the market. It may be problematic to replace the membrane keyboard keycaps due to their design.
4.3 Customizability
As a result of the mechanics, it is almost impossible for you to make any changes to a membrane keyboard. You can, however, replace the switches and keycaps of a low profile mechanical keyboard easily.
There are now low profile QMK/VIA mechanical keyboards available on the market to enable users the ability to customize different backlight effects, macros, keycodes, and mouse commands on different keymap layers.
4.4 NKRO
Low profile mechanical keyboards usually allow you to press all keys simultaneously (NKRO). Many membrane keyboards don't support NKRO, most of them only allow for 3-4 keys to be registered at the same time.
4.5 Lifespan
Low profile mechanical keyboards last for 50 million to 100 million keypresses while membrane keyboards only serve 10 million to 20 million keypresses during their lifetime. If the switch is broken or the keycap is worn out, it is easily replaceable on a low profile mechanical keyboard. It is a different story for a membrane keyboard because you may have to replace the entire keyboard.