Re: Conformal coating of circuit boards(All Audi content)

[MSV96@aol.com]

In a note dated 2/28/97 Anton Gaidos III writes:

<<At one time, if at all did Audi begin to put a conformal coating on the
engine management circuit boards?>>

Unsure but probably not...My understanding is that Audi themselves did not
make these circuit boards-I was told (by Ned or TAP...not sure which) these
are made by Hitachi (which would lead me to believe they are produced as
cheap as possible!!!, hence no conformal coating).

<<When condensation builds up, unprotected traces have a perfect opportunity
to create contact between two running parallel.>>

While this can be a temporary concern (the moisture evaporating and the
circuit board drying out would cure any problems for a while...), the more
serious concern would be that of potential corrosion damaging the circuit
board beyond repair-I see it all the time in car amps and CD changers (in
fact just condemmed a CD changer for this the other day for a not too pleased
customer where I moonlight fixing this stuff). I would hope that the location
and sealing of the ECU would be better than aftermarket stereo
equipment...Tuners-is this a problem, what conditions are these boards in
when you do mods?

<<If none of Audi's boards are conformally coated, I would highly recommend
this be something we all do at the time of chip upgrades. It is simple to
clean the surface and give it a quick spray. Any info on this, especially
from those who perform this upgrade regularly would be great.>>

I don't perform these upgrades (though anybody who wishes can contact me
about performing the mechanical soldering process to remove the chip and
install a socket as I am well versed and equipped to handle this proceedure),
but would concurr that it wouldn't be a bad idea. In fact, IF the circuit
boards ARE conformally coated, then re-coating would have to be part of any
professional modifications that required touching the circuit board with a
soldering iron. We (at my regular employer) conformally coat circuit boards
which are used for commercial dishwashing dispensing equipment and it works
very well (Chemtronics Conform is the variety we use). Good advice Anton!!!

Mike Veglia
85 4ksq