Cleaning leaked electrolytic & corrosion on PCB

D

DaveC

Guest
What is the best method for cleaning up leaked electrolyte? This PCB has some
corrosion on IC leads and vias.

Is there a corrosion neutralizer that would be effective? Since the potential
for corrosion in places that aren't accessible (deep in the vias), a liquid
that can neutralize corrosion is called for.

Would something like DeOxit work in such an application?

This is on a Tek scope acquisition board.

Thanks.
 
DaveC <invalid@invalid.net> wrote in message
news:0001HW.C7E60E6D00EF5EC4B01AD9AF@news.eternal-september.org...
What is the best method for cleaning up leaked electrolyte? This PCB has
some
corrosion on IC leads and vias.

Is there a corrosion neutralizer that would be effective? Since the
potential
for corrosion in places that aren't accessible (deep in the vias), a
liquid
that can neutralize corrosion is called for.

Would something like DeOxit work in such an application?

This is on a Tek scope acquisition board.

Thanks.
Click to expand...

litmus test first to see of acidic or alkaline and go for the opposite as
cleaner ?

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://diverse.4mg.com/index.htm
 
"DaveC" <invalid@invalid.net> wrote in message
news:0001HW.C7E60E6D00EF5EC4B01AD9AF@news.eternal-september.org...
What is the best method for cleaning up leaked electrolyte? This PCB has
some
corrosion on IC leads and vias.

Is there a corrosion neutralizer that would be effective? Since the
potential
for corrosion in places that aren't accessible (deep in the vias), a
liquid
that can neutralize corrosion is called for.

Would something like DeOxit work in such an application?

This is on a Tek scope acquisition board.

Thanks.
Click to expand...
If you can beg or borrow an ultrasonic cleaner, ordinary water with a dash
of washing up liquid will do fine,

Any crystals or ceramic resonaters should be removed before ultrasonic
cleaning.

If the construction of any components mean they trap water, a second dip
without detergent will be needed, and you may have to bake the board to dry
everything - the pre-heat phase on a SMD oven should do it.
 
DaveC wrote:
What is the best method for cleaning up leaked electrolyte? This PCB has some
corrosion on IC leads and vias.

Is there a corrosion neutralizer that would be effective? Since the potential
for corrosion in places that aren't accessible (deep in the vias), a liquid
that can neutralize corrosion is called for.

Would something like DeOxit work in such an application?

This is on a Tek scope acquisition board.

Thanks.
Click to expand...

I scrub with white vinegar and a toothbrush, then rinse with alcohol. If
the corrosion is more severe, mechanical methods may be needed,
Scotchbrite type cleaning pads work well but you have to be careful not
to damage fine traces. In some cases it's best to neutralize and then
clean off as much residue as possible and then leave the remaining
corrosion alone.
 
On Sat, 10 Apr 2010 11:15:57 -0700, DaveC <invalid@invalid.net> wrote:

What is the best method for cleaning up leaked electrolyte? This PCB has some
corrosion on IC leads and vias.

Is there a corrosion neutralizer that would be effective? Since the potential
for corrosion in places that aren't accessible (deep in the vias), a liquid
that can neutralize corrosion is called for.

Would something like DeOxit work in such an application?

This is on a Tek scope acquisition board.

Thanks.
Click to expand...
Dishwasher.

John
 
On 11/04/2010 5:43 AM, John Larkin wrote:
On Sat, 10 Apr 2010 11:15:57 -0700, DaveC<invalid@invalid.net> wrote:

What is the best method for cleaning up leaked electrolyte? This PCB has some
corrosion on IC leads and vias.

Is there a corrosion neutralizer that would be effective? Since the potential
for corrosion in places that aren't accessible (deep in the vias), a liquid
that can neutralize corrosion is called for.

Would something like DeOxit work in such an application?

This is on a Tek scope acquisition board.

Thanks.

Dishwasher.

John
Click to expand...
You must be single.
 
"N_Cook" <diverse@tcp.co.uk> wrote in news:hpqhja$apo$1@news.eternal-
september.org:

DaveC <invalid@invalid.net> wrote in message
news:0001HW.C7E60E6D00EF5EC4B01AD9AF@news.eternal-september.org...
What is the best method for cleaning up leaked electrolyte? This PCB has
some
corrosion on IC leads and vias.

Is there a corrosion neutralizer that would be effective? Since the
potential
for corrosion in places that aren't accessible (deep in the vias), a
liquid
that can neutralize corrosion is called for.

Would something like DeOxit work in such an application?

This is on a Tek scope acquisition board.

Thanks.



litmus test first to see of acidic or alkaline and go for the opposite as
cleaner ?

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://diverse.4mg.com/index.htm
Click to expand...
use vinegar if an alkaline electrolytic,or sodium bicarbonate(baking
soda)solution if acidic. then rinse well,prferably with distilled
water,then some 90% isopropyl alcohol to dry.

use a cotton swab soaked in one of the solutions to test it,then try the
other on a new swab.

vias would probably wick up the solution by capillary action.


--
Jim Yanik
jyanik
at
localnet
dot com
 
On Sat, 10 Apr 2010 11:15:57 -0700, DaveC <invalid@invalid.net> wrote:

What is the best method for cleaning up leaked electrolyte?
Click to expand...
The electrolyte is mostly a weak organic acid. Neutralizing it with
any manner of mild base will prevent further corrosion. I use
household cleaner, such as 409. You can tell that it's working if the
liquid foams slightly on contact.

This PCB has some
corrosion on IC leads and vias.
Click to expand...
409 will also break up the copper sulfate. However, you'll have to
wash off the residue.

Is there a corrosion neutralizer that would be effective? Since the potential
for corrosion in places that aren't accessible (deep in the vias), a liquid
that can neutralize corrosion is called for.
Click to expand...
The trick is not neutralizing the electrolyte. It's cleaning up the
mess afterwards. I smear the residue and "suds" around with a paint
brush, wash with water and/or alcohol, and then use compressed air to
blow as much of the liquid away (so it will dry quicker). Canned air
doesn't work well. An air compressor and nozzle work just fine.

Would something like DeOxit work in such an application?
Click to expand...
No. It will leave an oily residue that will eventually turn into a
big mess when the dust lands on the oil. It's also kinda expensive
for washing boards.

This is on a Tek scope acquisition board.
Click to expand...
Obviously, there's no need to supply a Tek model number. Many such
pieces of test equipment are very sensitive to leakage caused by board
contamination. For such boards, you may need to give it an alcohol
bath, possibly several times.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
 
David Eather <eather@tpg.com.au> wrote in
news:f-OdnQDYA-OYfF3WnZ2dnUVZ_tWdnZ2d@supernews.com:

On 11/04/2010 5:43 AM, John Larkin wrote:
On Sat, 10 Apr 2010 11:15:57 -0700, DaveC<invalid@invalid.net
wrote:

What is the best method for cleaning up leaked electrolyte? This PCB
has some corrosion on IC leads and vias.

Is there a corrosion neutralizer that would be effective? Since the
potential for corrosion in places that aren't accessible (deep in
the vias), a liquid that can neutralize corrosion is called for.

Would something like DeOxit work in such an application?

This is on a Tek scope acquisition board.

Thanks.

Dishwasher.

John


You must be single.
Click to expand...
I've used my dishwasher and Calgonite to clean 2236 DMM boards,then a
drying session in our TEK field office's drying oven at around 140DegF for
3 days.

--
Jim Yanik
jyanik
at
localnet
dot com
 
David Eather wrote:
On 11/04/2010 5:43 AM, John Larkin wrote:
On Sat, 10 Apr 2010 11:15:57 -0700, DaveC<invalid@invalid.net> wrote:

What is the best method for cleaning up leaked electrolyte? This PCB
has some
corrosion on IC leads and vias.

Is there a corrosion neutralizer that would be effective? Since the
potential
for corrosion in places that aren't accessible (deep in the vias), a
liquid
that can neutralize corrosion is called for.

Would something like DeOxit work in such an application?

This is on a Tek scope acquisition board.

Thanks.

Dishwasher.

John


You must be single.
Click to expand...

You can always do it while the wife is out, it's not gonna damage anything.

When I was a teenager I occasionally washed engine parts in the
dishwasher, not something I'd recommend, but my mom never found out.
 
On Sat, 10 Apr 2010 19:19:20 -0700, James Sweet <jamesrsweet@gmail.com>
wrote:

David Eather wrote:
On 11/04/2010 5:43 AM, John Larkin wrote:
On Sat, 10 Apr 2010 11:15:57 -0700, DaveC<invalid@invalid.net> wrote:

What is the best method for cleaning up leaked electrolyte? This PCB
has some
corrosion on IC leads and vias.

Is there a corrosion neutralizer that would be effective? Since the
potential
for corrosion in places that aren't accessible (deep in the vias), a
liquid
that can neutralize corrosion is called for.

Would something like DeOxit work in such an application?

This is on a Tek scope acquisition board.

Thanks.

Dishwasher.

John


You must be single.


You can always do it while the wife is out, it's not gonna damage anything.

When I was a teenager I occasionally washed engine parts in the
dishwasher, not something I'd recommend, but my mom never found out.
Click to expand...

Just be sure to do a 60 C bake for about a half hour afterward.
 
DaveC <invalid@invalid.net> wrote:

What is the best method for cleaning up leaked electrolyte? This PCB has some
corrosion on IC leads and vias.

Is there a corrosion neutralizer that would be effective? Since the potential
for corrosion in places that aren't accessible (deep in the vias), a liquid
that can neutralize corrosion is called for.

Would something like DeOxit work in such an application?

This is on a Tek scope acquisition board.
Click to expand...
Hmm, you bought a TDS5xx? There is a lot about cleaning these board on
the Tektronix user forum on their website.

--
Failure does not prove something is impossible, failure simply
indicates you are not using the right tools...
nico@nctdevpuntnl (punt=.)
--------------------------------------------------------------
 
["Followup-To:" header set to sci.electronics.design.]
John Larkin wrote:
On Sat, 10 Apr 2010 11:15:57 -0700, DaveC <invalid@invalid.net> wrote:

What is the best method for cleaning up leaked electrolyte? This PCB has some
corrosion on IC leads and vias.

Is there a corrosion neutralizer that would be effective? Since the potential
for corrosion in places that aren't accessible (deep in the vias), a liquid
that can neutralize corrosion is called for.

Would something like DeOxit work in such an application?

This is on a Tek scope acquisition board.

Thanks.

Dishwasher.
Click to expand...
Excellent advice. A household dishwasher (with the normal powder
detergent) is an extremely cheap and powerful cleaning device for almost
anything. It took me a while to convince my ex-lab to use one for
cleaning larger UHV parts rather than an appropriately-sized ultrasonic
tank which would have cost the equivalent of 100 dishwashers. There are
things that a dishwasher isn't good enough for, but they are few.

robert
 
"James Sweet" <jamesrsweet@gmail.com> wrote in message
news:hprbio$hj4$2@news.eternal-september.org...
David Eather wrote:
On 11/04/2010 5:43 AM, John Larkin wrote:
On Sat, 10 Apr 2010 11:15:57 -0700, DaveC<invalid@invalid.net> wrote:

What is the best method for cleaning up leaked electrolyte? This PCB
has some
corrosion on IC leads and vias.

Is there a corrosion neutralizer that would be effective? Since the
potential
for corrosion in places that aren't accessible (deep in the vias), a
liquid
that can neutralize corrosion is called for.

Would something like DeOxit work in such an application?

This is on a Tek scope acquisition board.

Thanks.

Dishwasher.

John


You must be single.


You can always do it while the wife is out, it's not gonna damage
anything.

When I was a teenager I occasionally washed engine parts in the
dishwasher, not something I'd recommend, but my mom never found out.
Click to expand...
It was a different story the one time I put a pan of trichloroethane on the
gas ring!
 
On Sun, 11 Apr 2010 10:16:27 GMT nico@puntnl.niks (Nico Coesel) wrote in
Message id: <4bc1a14f.1099558906@news.planet.nl>:

DaveC <invalid@invalid.net> wrote:

What is the best method for cleaning up leaked electrolyte? This PCB has some
corrosion on IC leads and vias.

Is there a corrosion neutralizer that would be effective? Since the potential
for corrosion in places that aren't accessible (deep in the vias), a liquid
that can neutralize corrosion is called for.

Would something like DeOxit work in such an application?

This is on a Tek scope acquisition board.

Hmm, you bought a TDS5xx? There is a lot about cleaning these board on
the Tektronix user forum on their website.
Click to expand...
Many TDS 6XX scopes also had this problem. I run them through a dish
washer first, then a Simple Green scrubbing followed by rinsing and blow
dry using a compressor. After that I scrub 'em again with isopropyl
alcohol, remove all the caps and replace with new ones. If it still
doesn't pass it's diagnostics and SPC, start looking for open vias
(usually black) and etches that are close to the areas where the worst of
the leakage was.
 
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