On Sat, Apr 17, 2004 at 08:49:21AM -0800, vartan enlightened us thusly
> I have a board which had a lithium battery explode unseen and was not
> noticed until we attempted to power it on (quite some time later,
> possibly a year or more...). The PCB itself seems fine, oddly enough,
> but anywhere that the acid hit metal (RFI shields, switches) it
> blossomed with massive rust (ok, corrosion, oxidation, what have you).
>
> Does anyone have any advice for a special method to try and clean off
> the board? I know there are things that you can immerse/saturate
> circuit boards in to remove contaminants but I wasn't sure where
> exactly to start. Plus, I'm not even sure if it's worth the time if it
> turns out to not work after all my best efforts.
>
> It's the first time I've seen one of these type batteries explode, I
> believe it's an N-Type 3.6v, it must have been dead beyond dead. But
> all the damage was hidden underneath another part. It seems strange to
> me that the board, caps and resistors in the 'blast radius' look
> relatively unscathed other than bubbles and flakes of metal from the
> nearby shielding.
I have had pretty instant success with a fibre glass brush. These are
available for cleaning tarnish from RS or other such suppliers. Refills
are also available.
CAVEATS & WARNINGS:
If you go at the board with this any way roughly, you will lose the
'shadows' of the traces; so make sure you know what is/was connected to
what before you start.
Have a piece of rough cast iron (I find my Metcal soldering Iron stand
excellent) to clean the brush periodically. Just give it a little extra
length, rub lightly on a rough surface, and the dust flies out of it.
Watch out for the splinters from broken brush ends, which are near
invisible :-(.
That said, it is an excellent service tool, and cheap too. It also
allows you to remove any degraded or carbonised pcb.
--
With Best Regards,
Declan Moriarty.
--
Author: Declan Moriarty
INET: [EMAIL PROTECTED]
Fat City Hosting, San Diego, California -- http://www.fatcity.com
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