Two More (Unannounced) Low-Profile Kailh Switches

LAS VEGAS, NV -- When we last looked at the low-profile mechanical switches from Kaihua, we noted that although most of the new models held a lot of promise for laptops and slim desktop keyboards, the scissor-switch design it had in development had some issues. It would seem that Kaihua isn’t satisfied yet either, because we spotted some artwork in the company’s CES booth that indicates another scissor design is in the works, as well as a new and unique laptop switch.

There’s nothing official, and there were no prototype switches in the booth, but this follows what Kaihua did at Computex: It had some of its switch prototypes on display and some renders on the wall. Those renders eventually turned into prototype switches that we got our hands on, so it follows that the images we spotted at CES will become Real Things, too.

Another Scissor Design: PG1421

Kaihua now has at least three mechanical scissor-switch designs for laptops, in various stages of completion--the PG1425 and PG1442, and now the PG1421. The PG1425 has a unique horizontal spring, although we still aren’t certain if that spring impacts the stem, the scissor arms, or both. The PG1442 has a centered light pipe design, which is ideal for backlighting, and it has a vertical spring (just like most switches) that makes the whole package taller than the PG1425.

The new PG1421 appears to have borrowed from both of the aforementioned designs. We’re speculating here, and it’s difficult to draw firm conclusions from a single render, but it appears that the PG1421 uses both a horizontal spring and clear middle housing that may offer some of the same benefits as the PG1442’s light pipe.

The horizontal spring should enable a switch package that’s as thin as the PG1425. The middle part of the switch looks to be clear--like RGB switches--but the surrounding pieces are opaque. That means an LED could be more or less centered under the switch yet shine only through the middle of the housing.

Even More Laptop-y: PG1325

The PG1325 switch render looks nearly identical to the PG1425 switches at first glance, but upon closer inspection, there’s a crucial difference: no switch stem. Among all the many mechanical switch variations and designs from Kaihua and its chief rivals, they’ve all had a stem; as far as we’re aware, then, this is a first.

It appears that there are no scissor arms, either. Instead, there’s just a flat piece of metal attached to a spring. We presume that this piece of metal is what the keycap pushes on when you press down. Kaihua should easily be able to make that action linear or clicky or tactile depending on what it adds to (or subtracts from) the chassis the metal touches.

Such a design could eliminate any issues with weak scissor arms, and it could further reduce the height of the switch package. The total package height of the low-profile PG1350 (Chocolate) switch is only 8mm (sans keycap), and the PG1425 is about half that. If Kaihua indeed ditched the switch stem and scissor arms from the PG1425, that’s about another 1-1.5mm, making the total switch package of the PG1325 an astounding 2.5-3mm.  

Again, we’re only able to speculate about the PG1325; we’re basing all of our observations about it on a single image, so take all of the above with a grain of salt. But if our observations and assumptions are correct, the PG1325 should fit onto any slim Ultrabook-type laptop.

A Linear PG1442

A final surprise at Kaihua’s CES booth was a linear variant of the PG1442. Previously, we knew only that there would be a clicky version (the one we recently tore down), but now we know there will at least be a linear version. It exists, and we were able to type on a PCB sample. More than the clicky PG1442s, the linear version feels most similar to a laptop typing experience, but obviously with the advantage of a mechanical switch over the rubber dome/scissor switches found in most laptops.

Let The Competition Roll

There’s now bona fide competition in the low-profile switch market. Cherry announced its first post-Cherry ML low-profile switch, alongside several prototype keyboards from various partners, and of course TTC is still making a play, mostly via Tesoro’s keyboards (which we also got a sneak peek of at CES). Kaihua, for its part, has only so many designs with its low-profile switches in the wild--we know of one or two community projects, plus a few shipping keyboards that we’ve covered--but it’s certainly leading the pack when it comes to rapidly developing and prototyping new designs.

Below is a table with our most up-to-date information on Kaihua’s low-profile switches. We still do not have full specifications on some of them, and as stated above, a couple are only theoretical because we’ve seen only images and no prototypes.

Kaihua Low-Profile SwitchesPG1350 (Choc)PG1232 (Mini Choc)PG1442PG1425PG1421PG1325
TypeLinear, tactile, clickyClickyLinear, clickyClicky, tactile----
Actuation Point1.5mm (+/-0.5mm)1.2mm (+/-0.5mm)1.4mm (+/-0.3mm)------
Actuation Force50gf50gf50gf (+/-10gf)------
Pressure Point Force60gf60gf55gf------
ActionStandardStandardScissor (vertical slider)Scissor (horizontal slider)Scissor (horizontal slider)Metal plate with spring
LED LocationTop of switch housingTop of switch housingCenterTop of switch housingCenter (?)Top of switch housing
Total Travel3mm (+/-0.5mm)2.4mm (+/-0.5mm)2.7(+/-0.2mm)------
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