Technical Description Final Draft
Mahir Shahriar
Writing for Engineering ENGL 21007
Professor Sara Jacobson
City College of New York

Outline

⦁ Introduction
⦁ Body
⦁ Casing
⦁ PCB (Printed circuit board)
⦁ Plate + Stabilizers
⦁ Gasket
⦁ Switches
⦁ Keycaps
⦁ Conclusion
⦁ References

Introduction
In this day and age, keyboards are an essential part of everyday life. Keyboards are how we type on computers and devices, with most jobs nowadays requiring proficiency in typing. While it has become an integral part of our everyday lives, many people don’t know how this technological innovation came to be. The modern-day keyboard stems from the typewriter. The typewriter, created by Christopher Latham Sholes, alongside Samuel W. Soule, Carlos Glidden, and John Pratt, was a machine that would allow people to hit keys on a machine that would print those letters onto a sheet of paper. Sholes and the other inventors also set the standard on typewriters to follow the QWERTY format, the format of how the letters on our keyboard are arranged today. At the time, the typewriter did its job, it allowed people to print words onto paper to record them effortlessly. However, the age of computers was upon us, and people needed a way to input information into that computer. To this end, they modified the design of the typewriter. Instead of typing things onto a piece of paper, you would type stuff onto the keyboard and the computer would record and process that information. That is when keyboards started gaining popularity, with the IBM Model F standing out in particular during the 1980s for its loud and clicky spring-key switches. Although keyboards are widespread in our daily lives, many people don’t know the different components of a modern-day mechanical keyboard or what they do.

Figure 1: Remington Standard typewriter Figure 2: IBM Model F Keyboard

Parts of a Modern-Day Mechanical Keyboard

⦁ Case
The outermost layer of the keyboard is known as the case or casing. The casing serves as the home for the keyboard. Its main job is to protect the PCB, Printed Circuit Board, or the brain and functional part of the keyboard, from any damage from external factors. Most keyboard cases are made of ABS plastic, but they can be made out of almost any material as long as it can protect the PCB, with popular materials being aluminum, carbon fiber, brass, and even wood. With that in mind, most people look to the design and material of the case mainly for its aesthetics as opposed to how well it can protect the PCB, as there aren’t many things that can damage the keyboard PCB through the case that would occur in everyday use of it.

Figure 3: KBDFans Tofu 84 Aluminum Mechanical Keyboard Case (Grey)

⦁ PCB (Printed Circuit Board)
The PCB of the keyboard acts as the brain of the keyboard. It contains all the electronics, conductors, and circuits that take the inputs from the switches and turn them into electrical signals for the computer to process. These PCBs are normally made up of glass fiber with traces of copper. The switches of the keyboard are attached to the PCB to allow the PCB to read the keystrokes. In most cases, the switches are soldered onto the PCB for stability, but in recent times, people have been using PCBs where they can freely swap switches without the need to solder for more customizability.

Figure 4: DK 4 Professional Keyboard PCB

⦁ Plate + Stabilizers
The plate of the keyboard is used for stability and support for the switches. It gets aligned with the switches and PCB and the switches are clipped into the plate before getting soldered onto the PCB. This allows each keystroke to be more consistent and accurate while giving some protection to the PCB from small dirt and debris that could fall between the keycaps. The stabilizers also clip onto the plate and get soldered onto the PCB like the key switches, however, they serve the same purpose as the plate, they help stabilize and improve the consistency of the bigger keys, such as the space bar.

Figure 5: 60% Aluminum Top Plate

⦁ Gasket
The gasket is like a second layer to the plate, although its job is mainly for protection rather than stability. The gasket protects the internal parts such as the PCB from dirt, water, drink, and other spills or messes that could find their way into the keyboard and damage the parts; however, gaskets are not mandatory and are often not used as many keyboard connoisseurs practice keeping their keyboard station clean and tidy and try to keep anything that could damage the internal components away from that space. These are often a layer of rubber placed above the plate.

⦁ Switches
Switches are by far the most important part of a mechanical keyboard. They determine the feel, sound, and response of the keyboard during use. They can send keystrokes to the PCB through the crosspoint, by closing the circuit on the PCB which sends the signal to the computer, which allows the keyboard to even function as a keyboard. The parts of the switch all have their purpose: the upper housing is the part of the switch that gets attached to the keycap, the stem is the part of the switch that physically moves down when pressed to activate the contact, the crosspoint as mentioned before closes to the circuit to send the signals to the computer, the spring puts pressure on the keycap when pressed to allow it to return to its original position and the housing base is what gets snapped into the plate and soldered into the PCB. These switches are where people go crazy over preference. There are many styles of switches, such as clicky, linear, tactile, and creamy switches. All of these terms refer to the response or feedback in feeling that each of the switches gives to the user when typing, giving people full control of their typing experience. For example, clicky switches give an audible click sound when compressed and have a slight bump when pressed down, while tactile switches have that slight bump but lack that ‘click’ sound from a clicky switch, and a linear switch lacks both that bump and sound.

Figure 6: Standard Mechanical Switch Build
⦁ Keycaps
Keycaps are the physical parts of the keyboard that our fingers touch when we type. They are attached to the top housing of the switch. It pushes down the stem of the switch which sends the signal through the crosspoint into the PCB to allow our computer to read it. Keycaps are mainly preferential. They are mostly made from either Polybutylene Terephthalate (PBT) or Acrylonitrile Butadiene Styrene (ABS), with PBT being much more durable than ABS, making it the much better and popular choice; however, keycaps can be made with almost any material for the same reasons that the case can be made of almost anything. If the keycaps are made with ABS or PBT, they can be either single-shot or double-shot, with single-shot being made from one layer of plastic, and double-shot being made of two layers of plastic molded together., with double-shot PBT being the best and most popular option due to the high durability and quality. Most of the preference for keycaps comes from their feeling stemming from the material they are made of, their shape, and most importantly their design. Their shape places a small preferential role, with mainly the height being a thing of concern for some. There aren’t any tangible differences in performance for the different shapes of keycaps, but theoretically tall keycaps should take longer for the switch to react to, but any differences are negligible. The main aspect of customizability comes from designs, as there are thousands of keycap set designs and hundreds of new ones being designed every month.

Figure 7: Difference Between Three Most Popular Keycap Shapes

Figures 8, 9, 10: Different Keycap Sets Designs

Conclusion
For something so intertwined with our daily lives, it is surprising to see how many people are unaware of the components that go into the keyboard they use daily. The evolution of the modern-day mechanical keyboard from its conception as a typewriter that needed to be adapted for the age of computers is remarkable, and yet the two are incredibly similar. Nowadays, most keyboards are very similar, with the difference and each of the parts coming down to the personal preference of the user to give themselves their perfect typing experience.



References
Das Keyboard Staff. (2024, January 12). All the parts of a mechanical keyboard explained. Das Keyboard Mechanical Keyboard Blog. https://www.daskeyboard.com/blog/parts-of-a-mechanical-keyboard/
Squashy Boy. (2019, June 9). Building my first custom keyboard. YouTube. https://www.youtube.com/watch?v=IgfLKKPKXxA
Hypyo Tech. (2022, January 29). How to build your first custom keyboard! (on a budget). YouTube. https://www.youtube.com/watch?v=Sm1DVbyeDiI
Wikimedia Foundation. (2024, March 27). Christopher Latham Sholes. Wikipedia. https://en.wikipedia.org/wiki/Christopher_Latham_Sholes#:~:text=Christopher%20Latham%20Sholes%20(February%2014,typewriter%20in%20the%20United%20States.
NIHF inductee and typewriter inventor Christopher Sholes. NIHF Inductee and Typewriter Inventor. (n.d.). https://www.invent.org/inductees/christopher-sholes
Figure 1: Encyclopædia Britannica, inc. (2024, March 7). Typewriter. Encyclopædia Britannica. https://www.britannica.com/technology/typewriter#/media/1/611749/210840
Encyclopædia Britannica, inc. (2024a, March 7). Typewriter. Encyclopædia Britannica. https://www.britannica.com/technology/typewriter
Figure 2: IBM PC keyboard. (2024, March 27). In Wikipedia. https://en.wikipedia.org/wiki/IBM_PC_keyboard
Figure 3: Tofu 84 aluminum mechanical keyboard case (grey) (KBDFans). mechanicalkeyboards.com. (n.d.). https://mechanicalkeyboards.com/shop/index.php?l=product_detail&p=8481
Figures 4, 5, 6, and 7: Das Keyboard Staff. (2024, January 12). All the parts of a mechanical keyboard explained. Das Keyboard Mechanical Keyboard Blog. https://www.daskeyboard.com/blog/parts-of-a-mechanical-keyboard/
Figure 8: Amazon.com: JSJT Custom Keycap-keycaps 60 percent suitable for GK61/GK64/RK61/Anne /alt61 mechanical keyboards 71 key with Japanese font set OEM profile PBT keycaps with Keycap Puller (plum blossom keycaps) : Electronics. Amazon. (n.d.). https://www.amazon.com/JSJT-Keycap-Keycaps-Suitable-Mechanical-Keyboards/dp/B09L1BCFV3
Figure 9: Amazon.com: PBT Keycaps 132 Keys, great wave off Kanagawa Japanese keyboard keycaps, 5 side dye-sub custom Keycap set, cherry profile keycaps for Cherry Gateron MX switches mechanical keyboard US and UK layouts : Electronics. Amazon. (n.d.-b). https://www.amazon.com/Kanagawa-Japanese-Keyboard-Switches-Mechanical/dp/B0BJ1H33DM
Figure 10: Galaxy PBT KEYCAPS. kineticlabs.com. (n.d.). https://kineticlabs.com/keycaps/polycaps/galaxy-pbt