The PCB (Printed Circuit Board) is essentially the motherboard of your keyboard, housing all the electronic components and software. It includes the sockets for switches, the USB port connection, wireless communication (in wireless keyboards), and, in compatible models, RGB lighting.
Your primary decision is whether to choose a keyboard with a Hotswap PCB, which allows switches to be easily replaced without soldering, or a non-Hotswap PCB that requires soldering skills and equipment to attach the switches. I strongly recommend the first option, as it provides greater flexibility for future upgrades or modifications.
North vs. South Facing Sockets
Another, less critical choice involves the orientation of the PCB. Switch sockets can face either north (away from the user) or south (toward the user). Why does this matter? For two reasons:
Keycap Compatibility: When switches are north-facing, the keycap above them is installed on the “wrong side.” While this isn’t an issue with most keycap profiles, it can cause physical interference with Cherry profile keycaps — the most popular profile — leading to an unintended clicking sound when pressed. If the keyboard is Pre-built, it will already include compatible keycaps, so you won’t face any issues. However, if you plan to swap out the keycaps or switches later, this could become a problem.
RGB Lighting: With south-facing PCBs, the LED placement is closer to the user, resulting in slightly brighter and more prominent lighting compared to north-facing PCBs.
Lately, the majority of keyboards — even budget models — come with south-facing PCBs. There’s little reason to settle for a north-facing PCB anymore.
Board Thickness and Flexibility
PCBs are typically available in two thicknesses: 1.6 mm or 1.2 mm. A thinner PCB provides more typing flexibility, but if you opt for a keyboard with a thinner board, it’s essential to ensure the stabilizers you use are compatible with the thinner profile.
Some PCBs feature Flex Cuts — horizontal slots that add extra flexibility and contribute to a bouncier typing feel compared to regular boards. While these cuts enhance flexibility, they can also affect the keyboard’s sound profile, as sound waves pass through the slots downward.
If you plan to build your keyboard with sound-dampening foam, this won’t make much of a difference. However, if you’re aiming for a “clacky” build without foam, the flex cuts may make the sound thinner and less pronounced.
The Plate
In most mechanical keyboards, a component called the plate sits above the PCB. This plate is a sheet that matches the shape of the PCB and case, with cutouts for the switches and stabilizers. Its primary role is to provide stability, ensuring the switches are securely held in place and don’t shift.
Like every other element in a keyboard, the plate influences both the sound and typing feel. The most significant factor is the material it’s made of. Common plate materials include:
Aluminum: Affordable, strong, and rigid, providing a relatively firm typing feel and neutral sound with slightly higher-pitched tones.
Polycarbonate (PC) or Polypropylene (PP): Offer flexibility and a deeper sound.
FR4: A rigid plastic material, also commonly used for PCBs, offering a middle ground in terms of sound and flexibility.
Brass: Another rigid option, producing a deeper and louder sound compared to aluminum.
Carbon Fiber: Known for its distinctive loud, high-pitched sound profile.
Most keyboards come with a single plate, with polycarbonate being the most common material in budget models. For other materials, you’ll often need to purchase plates separately. In higher-end custom keyboard kits, multiple plates made from different materials may be included, allowing users to select their preferred option.
Plateless Build
Advanced enthusiasts sometimes opt to build a keyboard without a plate — using only switches mounted directly onto the PCB. This is a more challenging build since, without a supporting frame, the switches may detach from their sockets. As a result, plateless builds often rely on soldered PCBs instead of Hotswap sockets. A plateless keyboard can offer a very specific sound and an extremely soft, flexible typing experience, but this approach is generally recommended for experienced builders.
