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Topic: what is the name of these buttons? (Read 772 times) previous topic - next topic

look001

Sep 20, 2016, 08:54 pm Last Edit: Sep 20, 2016, 09:02 pm by look001
hey there,

i opened a old tv remote. I noticed that the buttons are different to what i have seen so far. There is a silicon layer. When i press a button the layer will be bend so it touches a pattern on the circuit board.

Here is also a photo:



what are these pads/ patterns called?

Thank you!

outsider

Membrane keypads, among other things.

INTP

#2
Sep 20, 2016, 09:02 pm Last Edit: Sep 20, 2016, 09:04 pm by INTP
There's probably a black spot on the underside to connect the traces on the PCB.
It's been called many things, try looking for conductive carbon buttons or some combination of conductive/dome/carbon/silicone/squishything.

It's pretty low tech stuff, just open traces that detect when they're connected. A moist finger would work or a piece of metal, conductive thread, whatever. The dome gives some tactility, but more importantly has a layer of carbon on the underside to do the conducting.

Some people call them capacitive buttons, but that's typically used to refer to the ones without a mechanical button.

outsider

Would you like to hear some of the things I've called them when trying to repair?....NAH  >:(

INTP

My first memories of such buttons were on a Betamax player

vaj4088

Silicon and silicone are two different things.  I do not think that you are seeing a "silicon layer."

123Splat


62Tom

They are elastomeric keypad buttons. The typically gold plated traces on the PCB get shorted by a small carbon pad on the underside of the button cover. If you ever need to clean them, isopropyl alcohol or non- residue contact cleaner work really well. DO NOT USE AN ABRASIVE !! Hope that info helps !!

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