Mechanical Keyboard Switch Parts: Names and Functions?

Here are the parts of a mechanical keyboard switch:

  • Upper Housing
  • Stem 
  • Crosspoint Contact 
  • Coil Spring 
  • Bottom Housing 

So if you want to learn all about the parts of a mechanical keyboard switch, their names, and functions, then this article is for you.

Let’s dig right in!

Table of Contents

Parts of a mechanical keyboard switch
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What Are the Parts of a Mechanical Keyboard Switch, Their Names, and Functions?

Mechanical Keyboard switches are what make mechanical keyboards unique and distinct from their membrane-based cousins.

Mechanical switches come in different designs and are made with different characteristics in mind. 

 mechanical keyboard switch keys.

But generally speaking, the internal parts inside a mechanical switch are almost always the same. 

This article will be exploring the internal workings of a mechanical switch and what different parts come together to make a mechanical switch. 

#1 Upper Housing

The upper housing of the mechanical switch functions as a precision guiding mechanism for the switch. 

The upper housing holds the other parts of the switch together in a tight and compact position.

Since mechanical switches involve the physical interactions of a lot of parts, it is important that a housing secures all these working parts. 

A gamer push the button on a mechanical keyboard with mechanical switches.

The upper housing helps guide the stem of the mechanical switch when it is pressed upon by the user via the keycaps.

Without an upper housing to guide the stem, consistent keystrokes are almost impossible. This is because the steam can buckle or not register the keypress properly when the user presses the keycap from an awkward angle.  

The upper housing brings consistency to the typing experience by always guiding the stem in the same direction. 

#2 Stem

The stem of the mechanical switch is a long-elongated plastic stick that is basically in contact with the keycap on the top. 

So, when the user presses down on a keycap, the user is actually exerting force onto the stem.

The stem of the mechanical switch comes down via the guidance of the upper housing and then registers the keystroke with the crosspoint contact.

These are usually metal contact leaves that send an electrical signal to the PCB (Printed Circuit Board) and via the PCB to the computer that a key has been pressed. 

A person cleans the keyboard with a brush.

Stems also serve another important function in the mechanical switch. Stems regulate the keystroke feel of each keypress.

This is very important because a lot of people buy mechanical keyboards for their feel. 

The three types of mechanical switches are:

  • Linear: These types of mechanical switches are known to have less of an audible click sound and are less tactile as well. Mechanical more tactical switches have these physical bumps feel to them that the user can experience. More tactical switches have more strong bumping experience. Liner switches are the least tactile and the least noisy of the mechanical switches. 
  • Tactile Switches: As the name suggests, these switches are more tactile. It means they offer stronger physical feedback to the person typing. Some people like this but others don’t. 
  • Clicky Switches: Clicky switches are the ones that have a more audible click with each keypress. Usually, people that prefer their mechanical keyboards to be noisy use clicky mechanical switches.
  • These types are then further divided into different colors with further characteristics and features. But generally, the features are a blend of these with some other smaller benefits. Like a silent, switches are known to be quite than any other type.   

#3 Crosspoint Contact

The crosspoint contact is usually metallic leaves that generate and send the electrical signal associated with each keypress.

When the user presses down on a key, the force is transferred to the stem of the mechanical switch. As the stem comes down, it forces contact between the two metallic leaves that generates the electrical signal.

Layout custom Aluminium mechanical keyboard with brass plate.

This is registered as a keystroke. 

This electrical signal travels to the PCB, which sends instructions to the computer about which key was pressed.

The crosspoint contact is the interface between the physical and the electrical worlds as it actuates the signal needed to register the keystroke. 

#4 Coil Spring

The coil spring rests at the bottom of the mechanical switch. The purpose of this coiled spring is to determine the actuating force needed for the keystroke.

By changing how rigid or flexible this coiled spring is, designers of mechanical switches can control how hard you need to press down on the key. 

A more rigid key requires more force to work, while a more flexible key requires less force to work. Again, this is done on the basis of personal preference. 

Keys on springs.

Some people like their mechanical switches to be easier to press, while others prefer their keys to be more rigid and require more force to press. 

The force required to register a keystroke is called the Actuation force. While the actuation force can drastically vary from keyboard to keyboard. 

It can range from 35 grams of force to 350 grams of force. But more commonly, you will find mechanical switches with ranges between 45 grams to 65 grams of actuation force. 

#5 Bottom Housing

The bottom housing of the keyboard is like the upper housing that basically holds the mechanical switch from the bottom.

Backlit mechanical keyboard numerical buttons.

This is also where the installation of the mechanical switch happens. It usually has a way for the crosspoint contacts to connect to the PCB. 

Overall, the bottom housing holds everything together. 

Where are the switches mounted?

The mechanical switches are usually mounded in two ways. 

The mounting of the mechanical switches is important to understand. Following are the two ways the mechanical switches are mounted.  

PCB Mounted

Simply put, the PCB mounting method is where the switches are mounted directly onto the PCB.

Electronic flex circuit board on inside keybord membrane.

This process is more cost-effective from a production standpoint but can result in a less sturdy keyboard.

Plate Mounted

Plate mounting is when switches are mounted to a metal or plastic plate that sits atop the PCB. 

A modern mechanical keyboard switches, black and white keycaps on the desk.

After the switches are installed into the plate, they are then soldered into the PCB.

This is more expensive for the manufacturer to produce; however, it can increase the overall stability of the keyboard.