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clean coating from PCB

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aurgathor

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Dec 10, 2004, 4:36:59 AM12/10/04
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I took apart a UPS, and the PCB, including a significant portion
of the components on it are coated with some kind of clear and
shiny lacquer. This is nice for some things, but now I can't read
the markings on the chips. What kind of cleaner is best to clean
the coating from the chips?

TIA,
aur


philo

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Dec 10, 2004, 5:43:14 PM12/10/04
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i'm sure this will work

http://www.mgchemicals.com/products/8310.html


but i'm also sure it'll be toxic as hell
so be sure to use it in a well ventelated area or outdoors

williamp.n.smith

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Dec 10, 2004, 6:42:06 PM12/10/04
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I'm not sure that it's supposed to come off, and any solvent that will
remove it will probably tear the {markings, epolxy bodies} right off
thise chips...

shofa...@woh.rr.com

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Dec 10, 2004, 7:39:39 PM12/10/04
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I think its called conformal coating and a real beast to try any repairs, I
inspected them and when the vendor repairs them they really look bad and
unreadble!!!
timba

"aurgathor" <spa...@if-you.com> wrote in message
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aurgathor

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Dec 11, 2004, 8:42:21 PM12/11/04
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Guess what, I figured I'll just try all my applicable household
chemicals starting with the mildest one (Isopropyl Rubbing
Alcohol), and I hit the jackpot right away!

A cotton swab dripped with rubbing alcohol plus a bit of
rubbing followed by wiping with dry toilet paper works
like a charm on this particular type of conformal coating.
(I only cleaned the top of the ICs so far)

I wonder if it's acrylic or urethane based, (based on one of
the posted link) and what does it going to do if I heat it up.

BTW, I found a bunch of comparators, some Schmitt triggers,
a PWM conroller, and a quad AND gate. Appears to be a
fairly trivial circuit.

Thanks for the links and the follow-ups.

<shofa...@woh.rr.com> wrote in message
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EN

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Mar 22, 2005, 1:30:59 AM3/22/05
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The clear coating is called conformal coating.
I guess you've found out that there are different kinds of conformal
coatings,
silicone and urathanes. I have used Zip-Strip, a paint stripper, and it
'does not'
remove any markings from the IC's. The conformal coating bubbles up.
Use running water to wash the board off.


"philo" <ph...@privacy.net> wrote in message
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