Raul
You may find it is lanolin, much used as a contact lubricant. Many
"contact cleaners" are solvents containing a small percentage of
lanolin, the idea that they remove the accumulated crud and leave just
sufficient lubricant to prevent fretting, which does happen with gold. I
believe that such deposits as you describe, where you can see the
colour, are too thick. It is not true that, if a little is good, a lot
is better! In the case of encoders, where you do not want too much
friction, a compromise is necessary, by keeping the wiper pressure low
(unlike rotary switches). The design and lubrication is therefore a
question of good engineering, to make sure that the pressure and number
of contact points are sufficient to ensure reliable contact, by
penetrating the organic film.
Brian
"Valdez, Raul (R.)" wrote:
>
> Hello,
> We are using rotary switch encoders on our application and they are failing,
> after some were opened, certain kind of yellow grease was found, we are not
> sure if that's flux since the encoder is being soldered to the board thru
> wave soldering.
>
> After cleaning the "defective" encoder with alcohol the encoder works fine.
>
> Anyone has had a similar experience?? soldering process or encoder supplier
> fault??
>
> Please help.
>
> Thanks.
>
> Raúl Valdéz.
>
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