[sdiy] keyboard question

[Simon Brouwer]

Ian Smith schreef:
> Hi all,
> I'm thinking of making a controller for my synth. I'm going to fashion it after a concertina. It's going to be a CV controller, not MIDI. I want to etch the buttonboard like a commercial keyboard to reduce the amount of rat's nest. My question is this: The black stuff that covers the contact points on commercial keyboards, what is it? where do I get it? and Is it really necessary? 
> -Ian Smith
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I think it's conductive carbon paste which is screen printed on the PCB. 
It provides a non-oxidizing contact interface when printed on copper. 
You see it used with silicone rubber pads where each button has a 
flexible, conductive carbon, contact area.

Are you aiming for very high-volume, low-cost production?
If not, why don't you use something like this (not that expensive either):
http://nl.farnell.com/tyco-electronics/fsm2jsma/tactile-switch-spno-smd/dp/3801287

-- 
Vriendelijke groet, 
Simon Brouwer. 

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