Cleaning leaked electrolytic & corrosion on PCB
in [Design]
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From: David Eather on 10 Apr 2010 16:35 On 11/04/2010 5:43 AM, John Larkin wrote: > On Sat, 10 Apr 2010 11:15:57 -0700, DaveC<invalid(a)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.
From: Jim Yanik on 10 Apr 2010 17:55 "N_Cook" <diverse(a)tcp.co.uk> wrote in news:hpqhja$apo$1(a)news.eternal- september.org: > DaveC <invalid(a)invalid.net> wrote in message > news:0001HW.C7E60E6D00EF5EC4B01AD9AF(a)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 > > > 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
From: Jeff Liebermann on 10 Apr 2010 17:56 On Sat, 10 Apr 2010 11:15:57 -0700, DaveC <invalid(a)invalid.net> wrote: >What is the best method for cleaning up leaked electrolyte? 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. 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. 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? 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. 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(a)cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
From: Jim Yanik on 10 Apr 2010 17:59 David Eather <eather(a)tpg.com.au> wrote in news:f-OdnQDYA-OYfF3WnZ2dnUVZ_tWdnZ2d(a)supernews.com: > On 11/04/2010 5:43 AM, John Larkin wrote: >> On Sat, 10 Apr 2010 11:15:57 -0700, DaveC<invalid(a)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. > 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
From: Archimedes' Lever on 10 Apr 2010 18:32
On Sat, 10 Apr 2010 16:59:31 -0500, Jim Yanik <jyanik(a)abuse.gov> wrote: >David Eather <eather(a)tpg.com.au> wrote in >news:f-OdnQDYA-OYfF3WnZ2dnUVZ_tWdnZ2d(a)supernews.com: > >> On 11/04/2010 5:43 AM, John Larkin wrote: >>> On Sat, 10 Apr 2010 11:15:57 -0700, DaveC<invalid(a)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. >> > >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. good job. A little vacuum would have been nice to have been able to have introduced for a few minutes during that heating session too. Ideally speaking. |