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04 / 06 · Mounting & materials
How the plate is mounted
The layers a mechanical keyboard is built from, and how the way the plate and PCB are held in the case (from integrated plate to gasket mount) changes the feel and the sound.
The layers of a keyboard
- Keycaps
- The key caps, the part you touch.
- Switches
- One mechanical switch per key.
- Mounting plate
- Holds the switches in place, sets how stiff the assembly is, and largely defines how typing feels and sounds.
- PCB
- The printed circuit board, which defines what the keyboard does.
- Case
- The outer shell, for example CNC-milled aluminium or injection-moulded polycarbonate.
The way the plate–PCB assembly is held in the case deeply affects how typing feels and the sound it makes. Although these are subjective, they matter for long-term comfort.
From the thesis, chapter 1.1, 2.1
Integrated plate and tray mount
The simplest constructions are also the stiffest. They are cheap and solid, but you pay for it in how typing feels.
Integrated plate
The plate is not a separate part but belongs to the top half of the case. The switches go straight into it.
Strengths
- The simplest and stiffest construction
- An extremely solid keyboard
Limits
- A very stiff, often harsh feel: the vibration of every press goes straight into the whole case
Tray mount
The plate–PCB assembly is screwed straight into mounting points in the bottom of the case.
Strengths
- Simple, stiff and cheap
Limits
- An inconsistent feel: keys near the screws are stiffer, those in the middle more flexible
From the thesis, chapter 2.1
Top, bottom and sandwich
These methods beat tray mount on consistency: the assembly is supported all the way around rather than at a few separate points, so the feel is much more even across the whole board.
Top mount
The plate has tabs that screw into the top half of the case.
Bottom mount
The reverse: the plate is fixed to the bottom half of the case.
Sandwich mount
The edges of the plate are clamped “like a sandwich” between the top and bottom halves and held firmly once the case is assembled.
Strengths
- A very solid build with a firm, consistent feel
Limits
- Like an integrated plate, it can be quite stiff and pass on a lot of vibration, depending on the materials
From the thesis, chapter 2.1
Gasket mount
Gasket mount is considered the premium method today. The plate–PCB assembly is not screwed down rigidly; it is “suspended” between the two halves of the case on gaskets made of flexible materials.
The gaskets isolate vibration, so typing becomes more pleasant, quieter and slightly springy. Less shock reaches your fingers, which can make long sessions more comfortable.
From the thesis, chapter 2.1
The methods compared
| Mount type | Stiffness | Tactile consistency | Complexity/Cost | Typical sound profile |
|---|---|---|---|---|
| Integrated Plate | Very high | Consistent | Low | Sharp, harsh |
| Tray Mount | Inconsistent | Low | Very low | Inconsistent, often hollow |
| Top/Bottom Mount | High | High | Medium | Full, consistent |
| Sandwich Mount | High | High | Medium | Firm, solid |
| Gasket Mount | Flexible | High | High | Damped, deep (“thocky”) |
In short
How a keyboard feels and sounds comes not only from its switches and layout but also from how the plate is mounted. Rigid methods are simple and cheap; gasket mount is more complex but damps vibration.
From the thesis, chapter 2.1
Materials and acoustics
Plate material
Polycarbonate
For flexibility and a deeper sound.
Case material
CNC-milled aluminium
A case machined from aluminium by CNC milling. The thesis also proposes it for a premium version of the prototype.
Injection-moulded polycarbonate
A polycarbonate plastic case made by injection moulding.
FDM 3D printing
Used for the case of the thesis prototype. The parts were oriented for maximum mechanical strength and as few support structures as possible.
Acoustic layers
Acoustic management also matters when designing a case: layers of foam or silicone added inside shape the sound of the keys and remove unwanted vibration.
From the thesis, chapter 1.2, 1.1
In the shop
Written from Ștefan-Emanuel Ciupitu’s bachelor thesis “Wireless multifunction keyboard using the nRF52840 module” (Suceava, 2025).