David van Horn wrote:
>>polymer quality problem. With good quality materials the conductive
>>plastic wears out first and stops being conductive after some time (1-2
>>years or more).
>
>That's interesting.. I've not seen this failure mode in our pads, even
>after 10+ years in LA (!)
>Different chemistry I guess.
>We do use gold on the keypads.
           ^^^^ What did I just say ? Gold is noble enough ;-) Anyway it
all depends on the 'pusher'. Apparently some conductive rubbers shed the
graphite compound which is not bound into the (it's a "sponge" soaked
(polymerized) with colloidal graphite). After X presses there is none left
...

Peter

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