Case Foam Should be Banned

Yes, I said it, case foam should not be used in mechanical keyboards, and here is why. Keyboards are a piece of technology first and foremost. Yes, the trends on social media and TikTok have shifted them toward a more aesthetic look, with new dynamic colors, shapes, and sounds, but beneath all that new garb, they still have PCBs with metal contacts and wiring. Those metal components, soldering joints, and wiring are in danger of corrosion, and this could be caused by....you guessed it....moisture!! We have all been taught not to put water near our electronics, and it's the same for keyboards. However, that shiny new $500 custom keyboard that you just stuck case foam into is a ticking time bomb.

Case foam was a fast-moving trend in the keyboard world, helping create what I would argue is one of the most popular sounds: the "thock". A deep, rich sound that is almost like muted rain. This sound is difficult to achieve, so people use various materials to create the sound aesthetic. First, it's the switches, the keyboard case material, the POM plate, and then the foam. Foam was found to dampen the echo inside metal cases and create a deeper, thockier sound. However, what they didn't tell you is that foam can trap moisture, which can lead to corrosion inside the keyboard. Corrosion could lead to irreparable damage to irreplaceable parts. Now that is a reason to stay away from case foam.

There are plenty of other ways to achieve a thocky sound without case foam. For instance, the mounting style changes the keyboard's sound profile. A gasket- or burger-mounted keyboard will give you the quietest sound without using case foam or a tape modification. Using POM or PP plates with your PCB will also create a muted sound. The switches also matter. Having a switch that is specifically deeper, with a lighter, longer spring, and a high amount of travel, will give you that thocky sound. Keycaps are also an important factor. Using heavier plastics, such as PBT, or other materials (metal and ceramic), will further dampen the sound. Cerakey is a great resource for heavy ceramic key caps that help with that thocky sound profile. They even sell pre-built boards with a plastic housing, which also dampens reverberation and sound caused by switches in a metal housing.

So, for those who want to achieve the "thock" aesthetic, do it without case foam, please! Or if you absolutely have to, at least use open-cell foams like Poron; DO NOT USE closed-cell neoprene, which can trap moisture against the PCB.