Keyboard Plates Explained
A keyboard plate is the structural layer that sits above the PCB and holds switches securely in place. It keeps switches properly aligned, reduces wobble in hot-swappable keyboards, and plays a major role in the keyboard's typing feel and sound profile. Different plate materials can significantly affect both acoustics and overall typing experience.
Keyboard Plates
Introduction
What are keyboard plates? A keyboard plate is an important part of the keyboard that sits above the PCB and acts as a switch holder to keep the switches perfectly aligned & positioned in their sockets.
Functions
Keyboard plates are essential because without a plate, switches in a hot-swap socket would wobble and might become loose while typing and pop out of the socket. Beside positioning the switches, the plates also help with tuning the acoustics of a keyboard, different plate materials paired with right switches determine the acoustics outcome of a keyboard. Plates sometimes also help with mounting the pcb on a keyboard.
Type of materials
Keyboard plates are made of many different materials to suit the different acoustic preferences of the hobbyists. The most common plate materials are: FR4, PC, Steel & Aluminium; other than these there also exists plates that are made of Carbon Fiber, Brass, Copper, ABS, Polypropylene, POM, Nylon, PEI, UHMWPE.
Materials and acoustics
Although the total typing acoustics depend on the full accumulated build of a keyboard, plate materials play a significant role in determining the final acoustic outcome. Generally as stiffness of a plate increases acoustically the pitch of the sound also increases, thus stiffer plates such as Aluminium, Steel, Carbon Fiber will provide a higher pitch typing acoustics (Clack) compared to PC, PP or POM plates which tames the higher frequencies while retaining and amplifying the lower frequencies (Thock), given that everything else is constant, while plate such as FR4 serves the neutral ground bringing out the mid frequencies which translates to a midtone velvety sound (Creamy/POP).
Pitch of the plate materials (Highest to Lowest)
Carbon Fibre
\
Steel
Aluminium
PEI
Brass
Copper
FR4
ABS
Nylon
PP
UHMWPE
POM
PC
Conclusion
Although the chart above determines the general facts about how acoustics vary because of plate material, the final typing acoustics also vary because of other factors like thickness of plate, barebone construction, type of switches, foams and modding materials. There are also builds that use solder PCBs thus the build does not require any plate for the switches as they are quite firmly positioned in the sockets of their respective PCBs. Still plates are an essential part of the keyboard and the hobby which helps to bring variation in the typing acoustics of a keyboard.