Cleaning leaked electrolytic & corrosion on PCB
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From: John Larkin on 11 Apr 2010 12:12 On 11 Apr 2010 11:29:21 GMT, Robert Latest <boblatest(a)yahoo.com> wrote: >["Followup-To:" header set to sci.electronics.design.] >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. > >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 The usual powder will etch aluminum. I keep warning my wife not to put aluminum stuff in the dishwasher, and her response is "how can you tell that something is aluminum?" John
From: Dave Platt on 11 Apr 2010 14:52 In article <82dq4hFguvU2(a)mid.uni-berlin.de>, Robert Latest <boblatest(a)yahoo.com> wrote: >> Dishwasher. > >Excellent advice. A household dishwasher (with the normal powder >detergent) is an extremely cheap and powerful cleaning device for almost >anything. Two tweaks on this advice: - It might be best to pick a powder detergent which is chlorine-bleach- free, to avoid any risk that the chlorine might attack PC-board traces. Bob Pease swears by Calgonite, which has no chlorine bleach in it. Some formulations of Cascade do have chlorine and should perhaps be avoided. - Take the board out after the wash-and-rinse cycles are complete, and give it a final manual rinse-down with distilled or deionized water... then shake and air-dry. Some home tap-water is high enough in minerals to leave a deposit, unless you use an anti-spotting agent... which might leave a surfactant film on the board which could cause unacceptable leakage in a high-Z circuit. -- Dave Platt <dplatt(a)radagast.org> AE6EO Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads!
From: John Devereux on 11 Apr 2010 15:58 John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> writes: > On 11 Apr 2010 11:29:21 GMT, Robert Latest <boblatest(a)yahoo.com> > wrote: > >>["Followup-To:" header set to sci.electronics.design.] >>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. >> >>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 > > The usual powder will etch aluminum. I keep warning my wife not to put > aluminum stuff in the dishwasher, and her response is "how can you > tell that something is aluminum?" .....By it being covered with fine grey powder when you take it out afterwards! -- John Devereux
From: JosephKK on 12 Apr 2010 01:04 On Sun, 11 Apr 2010 09:12:42 -0700, John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >On 11 Apr 2010 11:29:21 GMT, Robert Latest <boblatest(a)yahoo.com> >wrote: > >>["Followup-To:" header set to sci.electronics.design.] >>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. >> >>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 > >The usual powder will etch aluminum. I keep warning my wife not to put >aluminum stuff in the dishwasher, and her response is "how can you >tell that something is aluminum?" > >John > There are just a few to learn, the dark gray (new) to near black of cast iron, The pinkish orange of copper, the sheen of stainless steel (polished with a specular surface and "brushed"), and if it is not recognizably one of those it is aluminum. Most people keep track of their stainless steel due to significant cost. Teflon coatings are normally easy to find and normally occur on aluminum cookware and various utensils.
From: Tim Williams on 12 Apr 2010 02:22
"JosephKK" <quiettechblue(a)yahoo.com> wrote in message news:q1a5s5ldsrf79279kc8h9o9qb8kal1edlg(a)4ax.com... > There are just a few to learn, the dark gray (new) to near black of cast > iron, The pinkish orange of copper, the sheen of stainless steel (polished > with a specular surface and "brushed"), and if it is not recognizably one > of those it is aluminum. Most people keep track of their stainless steel > due to significant cost. Teflon coatings are normally easy to find and > normally occur on aluminum cookware and various utensils. Aluminum is easy to spot, it's usually a dull matte gray metallic finish. You don't see straight aluminum much anymore, mostly the old, dull, worn pots look like this. Considering the worn-ness of them already, I don't think I've ever noticed etching of such pots in the dishwasher before. Tim -- Deep Friar: a very philosophical monk. Website: http://webpages.charter.net/dawill/tmoranwms |