Mounting Styles Explained: Tray, Top, Gasket and Everything Between

A mounting style is simply the answer to one mechanical question: where does the force of your finger go once it passes through the switch? Every keystroke pushes down on the switch, which pushes on the plate and the PCB, which pushes on whatever holds them inside the case. The number of contact points, their position, and the stiffness of the material between them determine how far the assembly can move and how quickly it stops. That movement is what builders call flex, and its absence is what they call stiffness.

This matters because the plate assembly is also the loudest radiating surface in the board. A rigid mount transmits impact energy straight into the case walls, producing a brighter, higher-pitched report with a long tail. A compliant mount absorbs part of that energy as movement, shortening the decay and lowering the perceived pitch. Neither is a defect. A stiff board rewards a light, deliberate typing style; a soft board rewards people who bottom out hard and want the impact cushioned rather than reflected back into their fingertips.

Tray mount screws the PCB directly into standoffs moulded or machined into the bottom of the case. It is the oldest and cheapest arrangement, used by the vast majority of prebuilt boards and by nearly every sub-hundred-unit kit. The standoff positions come from the original Costar-era designs, which means they are unevenly distributed: several cluster near the centre and few reach the outer edges. That uneven spacing is the source of tray mount's reputation for inconsistency.

The practical result is that the area directly over a standoff is extremely stiff and slightly higher-pitched, while the regions between standoffs can flex noticeably and sound hollower. Builders call this the tray mount ping-pong effect, and it is why one half of a cheap board can sound different from the other. It is fixable to a large degree: case foam under the PCB, a strip of poron over each standoff, and correctly torqued screws remove most of the inconsistency. Do not dismiss tray mount — a well-damped tray board can outperform a badly executed gasket board easily.

Top mount screws the plate into posts on the upper case half, so the entire assembly hangs from the top piece with no contact at the bottom. Because the screw points sit near the perimeter and the middle of the plate is unsupported, top mount produces a distinctive profile: firm at the edges, progressively softer toward the centre, and typically a deep, contained sound because the case bottom is decoupled from the impact path. Most enthusiast aluminium boards of the last decade use it.

Bottom mount inverts the arrangement, fastening the plate to posts rising from the lower case half. Structurally it behaves similarly but tends to be a touch stiffer because the load path is shorter and the bottom half is usually the heavier, more rigid piece. Bottom mount also makes assembly easier since the plate sits in place while you work. Both styles are strongly affected by screw torque — overtightening compresses everything into a single rigid block and erases the character you paid for.

Gasket mount places a compliant material — poron, silicone, or moulded rubber — between the plate tabs and the case, so the assembly floats rather than bolting solid. Done well it delivers a uniform, cushioned keypress and a short, muted decay, which is why it dominates modern kit design. Done badly it delivers nothing at all: gaskets that are too thin, too hard, or crushed by overtightened screws behave exactly like a top mount with extra steps and extra cost.

Variations matter more than the label. Plate-tab gaskets are the common form. O-ring mount runs a continuous ring around the plate perimeter. Leaf-spring mount uses long flexible tabs cut into the plate itself. Burger mount sandwiches the plate between gaskets above and below. Sandwich mount clamps the plate edge between case halves and is actually quite stiff despite the friendly name. If a listing says 'gasket' without further detail, ask which variant and what durometer the material is; those two facts predict the feel better than the brand.

Pick by typing style rather than by trend. If you type lightly and value a crisp, articulate sound, a top mount with a stiff plate suits you. If you bottom out firmly and want the shock absorbed, a gasket mount with a soft plate and no plate foam will feel dramatically better on your joints over an eight-hour day. If your budget is tight, buy a tray mount kit and spend the difference on switches and keycaps, which change the experience just as much.

Whatever you choose, remember that mounting is tunable after purchase. Adding or removing plate foam, swapping plate material, backing screws off a quarter turn, or replacing stock gaskets with a different durometer all shift the result substantially and cost almost nothing. Our dampening material calculator estimates how much foam a given case volume needs, and the layout size calculator gives you the plate dimensions you need before ordering. Make one change at a time, type on it for a day, and keep notes — chasing three variables at once teaches you nothing.

One last caution about screws. Mounting hardware is the variable builders forget, and it silently overrides everything else. A gasket board with its screws driven fully home compresses the gaskets flat and becomes a rigid sandwich mount, which is why some owners report that their expensive flex-cut board feels like a cheap prebuilt. Tighten until the plate is captive and no further, then back each screw off roughly an eighth of a turn and work around the board in a cross pattern rather than sequentially. If the plate rattles, you have gone too far. Ten minutes with a screwdriver is genuinely the highest-value tuning session available on most keyboards, and it costs nothing at all.