BTC foam and foil

BTC foam and foil

File:Switch recognition--BTC--U mount.svg
Manufacturer	BTC
Switch type	Linear, tactile
Sense method	Capacitive
Keycap mount	Cherry MX mount Key Tronic or similar

BTC foam and foil is a foam and foil switch from BTC.

Description

As the capacitive mechanism provides no force, a spring or buckling rubber sleeve is placed under the keycap. BTC keyboards are generally readily identifiable by the rear label and the use of a 1.25 unit escape key. However, the discrete foam and foil modules are (typically, if not always) BTC branded on the top.

Variants

Force curve

Bothy linear and tactile versions exist. As with Key Tronic foam and foil, the linear version uses a helical spring under the keycap, while the tactile version uses a buckling rubber sleeve.

Keycap mount

These switches are most commonly found with Cherry MX mount sliders, but Key Tronic–shape sliders were also used.<ref name="GH-5060AT" /> Whether these sliders are compatible with Key Tronic keycaps is not confirmed. The Cherry MX mount sliders are externally identical to those of the more common BTC dome with slider switch.

Switch mount

Some BTC foam and foil keyboards use discrete slider modules along with a mounting plate, while others have the slider guide shafts moulded into the top case.

Colour

The sliders come in various colours including white, pink, and cyan.<ref name="eBay-5369" /> At least two slider colours may be found within the same keyboard, distributed at random.<ref name="DT-5060-SE" />

Keyboards

• BTC 53 series (linear and tactile; Cherry MX mount)
• BTC 5060 (linear; Cherry MX and Key Tronic–like/compatible mount)
• BTC 5100 (tactile; Cherry MX mount)
• BTC 5151 (linear; Key Tronic–like/compatible mount)

Gallery

Discrete

The BTC 5151 PCB has exposed pads, so the foam discs in theory will be insulated. This is a linear example with helical springs.

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  Circuit board top, with exposed pads
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  Top of key switch with spring
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  Switch module viewed from below, showing the foam pads and foil discs
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  Switch with spring removed
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  Keycap mount, keycap aspect

The BTC 5060 PCB does however have solder mask over the pads. The design of the slider modules is different to those in the BTC 5151.

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  Sense pads on the PCB are covered with solder mask, insulating them
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  Foil discs
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  Switch components

Non-discrete

The following pictures are from a BTC 5100. This example is tactile and uses buckling rubber sleeves.

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  Sliders with buckling rubber sleeves
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  Sliders with foil layers
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  Slider detail
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  Top of PCB with capacitive pads

References

<references> <ref name="eBay-5369">Telcontar.net — Keyboard reference photos</ref> <ref name="GH-5060AT">Geekhack — Blue Chip BTC-5060 vs non-branded version? Posted 2014-09-13. Retrieved 2015-07-23.</ref> <ref name="DT-5060-SE">Deskthority — NIB BTC Keyboards [Swedish doubleshots - MX compatible]</ref> </references>