Post by thread:[EE]:Cleaning PCB's ? [another monday morning stor

Over the weekend a person that calls himself an electrician (I call him something else, best not repeat it here), sprayed Silicon spray on a board in an effort to clean it and to get the board working again <insert your favourite comment here>. I was called in on Monday morning to look at the problem. It was a small problem initially, now it is a serious one, the board was dripping with Silicon and do all kinds of weird and wonderful things on the display when you switch it on. What can I use to clean the board? Thanks Quentin -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

At 08:18 AM 7/18/00 +0200, Quentin wrote: >Over the weekend a person that calls himself an electrician (I call him >something else, best not repeat it here), sprayed Silicon spray on a >board in an effort to clean it and to get the board working again At least it wasn't WD-40 >I was called in on Monday morning to look at the problem. It was a small >problem initially, now it is a serious one, the board was dripping with >Silicon and do all kinds of weird and wonderful things on the display >when you switch it on. > >What can I use to clean the board? Check the spray can, and see what the carrier is. It might be something reasonably obtainable. Good luck! -- http://www.SpamWhack.com A pre-emptive strike against spam Where's dave? http://www.findu.com/cgi-bin/find.cgi?kc6ete-9 My transistor sings with unintended parasitic the smoke escapes By Jeff Stout -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

>I was called in on Monday morning to look at the problem. It was a small >problem initially, now it is a serious one, the board was dripping with >Silicon and do all kinds of weird and wonderful things on the display >when you switch it on. >What can I use to clean the board? I would start by giving it a wash in something like isopropyl alcohol. If that does not work try warm soapy water. Either way if the silicon stuff is of a sort that tries to set in some way, you will probably need a selection of old toothbrushes handy. See there is a good reason for keeping those airline ones that come in their own protector! -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

> -----Original Message----- > From: David VanHorn [SMTP:spam_OUTdvanhornTakeThisOuTCEDAR.NET] > Sent: Tuesday, July 18, 2000 7:29 AM > To: .....PICLISTKILLspam@spam@MITVMA.MIT.EDU > Subject: Re: [EE]:Cleaning PCB's ? [another monday morning story] > > At 08:18 AM 7/18/00 +0200, Quentin wrote: > >Over the weekend a person that calls himself an electrician (I call him > >something else, best not repeat it here), sprayed Silicon spray on a > >board in an effort to clean it and to get the board working again > > At least it wasn't WD-40 > What's so bad about WD-40? ISTR it's only a light oil suspended in a solvent. I'm pretty sure there are no sillicons in it after following a thread on a car maintenance newsgroup. Mike -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

Quentin, I would suggest Freon and IPA (Isopropyl Alcohol). Use the FREON first. It will cut through the silicone spray rather well. After you get it pretty much clean with the Freon, use IPA to clean the Freon and the remaining silicone spray off. After this, it wouldn't hurt to wash the whole board in DI water if you have it available. If not, another wash with the IPA would be good. To dry, I would use compressed air to blow it dry. Look it over and if needed, touch up those areas that need it. After this, the board should be ready to go. This may sound like a long drawn out process, but in reality, it only tkaes a few minutes. Good luck. Regards, Jim On Mon, 17 July 2000, Quentin wrote: {Quote hidden}> > Over the weekend a person that calls himself an electrician (I call him > something else, best not repeat it here), sprayed Silicon spray on a > board in an effort to clean it and to get the board working again > <insert your favourite comment here>. > I was called in on Monday morning to look at the problem. It was a small > problem initially, now it is a serious one, the board was dripping with > Silicon and do all kinds of weird and wonderful things on the display > when you switch it on. > > What can I use to clean the board? > > Thanks > Quentin > > -- > http://www.piclist.com hint: The list server can filter out subtopics > (like ads or off topics) for you. See http://www.piclist.com/#topics jimKILLspamjpes.com -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

> >What's so bad about WD-40? ISTR it's only a light oil suspended in a >solvent. I'm pretty sure there are no sillicons in it after following a >thread on a car maintenance newsgroup. It attracts and captures dirt, and generally makes a mess. Silicones, for whatever else they do, don't attract dirt. -- http://www.SpamWhack.com A pre-emptive strike against spam Where's dave? http://www.findu.com/cgi-bin/find.cgi?kc6ete-9 My transistor sings with unintended parasitic the smoke escapes By Jeff Stout -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

In-Reply-To: <.....20000718134628.23318.cpmtaKILLspam.....c004.sfo.cp.net> James Paul <EraseMEjimspam_OUTTakeThisOuTJPES.COM> wrote: > I would suggest Freon Great. Make you own personal hole in the ozone layer. Brian Gregory. briangspam_OUTcix.co.uk -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

More realistic: Keep DuPont in the money. Freon isn't the problem, swimming pools are. The Freon deal was because DuPont (which owns the state of Delaware, and lots of politicians in Washington) patent was expired and they weren't seeing enough revenue. They had to come up with something different. There are much better, cleaner, safer refrigerants possible (including some you can make easily yourself, which are compatible with existing a/c systems). Do a web search and find out the truth. This is an example of business owning politicians, not of anything of technical merit. Andy Brian Gregory <@spam@briangKILLspamCIX.COMPULINK.CO.UK> on 07/18/2000 10:44:00 AM Please respond to KILLspambriangKILLspamcix.compulink.co.uk To: RemoveMEPICLISTTakeThisOuTMITVMA.MIT.EDU cc: (bcc: Andrew Kunz/TDI_NOTES) Subject: Re: [EE]:Cleaning PCB's ? [another monday morning story] In-Reply-To: <spamBeGone20000718134628.23318.cpmtaspamBeGonec004.sfo.cp.net> James Paul <TakeThisOuTjimEraseMEspam_OUTJPES.COM> wrote: > I would suggest Freon Great. Make you own personal hole in the ozone layer. Brian Gregory. RemoveMEbriangTakeThisOuTcix.co.uk -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

James Paul wrote: > Quentin, > > I would suggest Freon and IPA (Isopropyl Alcohol). Use the FREON > first. It will cut through the silicone spray rather well. After > you get it pretty much clean with the Freon, use IPA to clean the > Freon and the remaining silicone spray off. After this, it > wouldn't hurt to wash the whole board in DI water if you have it > available. If not, another wash with the IPA would be good. > I thought freon was on the endangered species list nowadaze. Also, in my expert hands, IPA always leaves a nasty scum on the pcb, which you then need another way to get rid of. - danM -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

> More realistic: Keep DuPont in the money. Freon isn't the problem, swimming > pools are. The Freon deal was because DuPont (which owns the state of Delaware, Maybe I missed something ... swimming pool, ozone?? I've never heard those two associated. -- Mitch -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

Dan, Apparently, you are doing it wrong then. I have used Freon TF to clean many many boards, followed by 1 or 2 cleanings with IPA, and they all come out clean enough to eat off of. Nice and squeaky. It takes a few minutes to do it, but the result is second to none. The key to not getting the IPA SCUM you speak of is to do a very thorough cleaning with the Freon TF first. I believe the SCUM you're getting is the mixture of IPA and the left over flux. At least that's been my experience. Regards, Jim On Tue, 18 July 2000, Dan Michaels wrote: {Quote hidden}> > James Paul wrote: > > Quentin, > > > > I would suggest Freon and IPA (Isopropyl Alcohol). Use the FREON > > first. It will cut through the silicone spray rather well. After > > you get it pretty much clean with the Freon, use IPA to clean the > > Freon and the remaining silicone spray off. After this, it > > wouldn't hurt to wash the whole board in DI water if you have it > > available. If not, another wash with the IPA would be good. > > > > I thought freon was on the endangered species list nowadaze. > > Also, in my expert hands, IPA always leaves a nasty scum on the > pcb, which you then need another way to get rid of. > > - danM > > -- > http://www.piclist.com hint: The list server can filter out subtopics > (like ads or off topics) for you. See http://www.piclist.com/#topics jimEraseME.....jpes.com -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

James Paul wrote: > Dan, > > Apparently, you are doing it wrong then. I have used Freon TF to > clean many many boards, followed by 1 or 2 cleanings with IPA, and > they all come out clean enough to eat off of. Nice and squeaky. > It takes a few minutes to do it, but the result is second to none. > The key to not getting the IPA SCUM you speak of is to do a very > thorough cleaning with the Freon TF first. I believe the SCUM you're > getting is the mixture of IPA and the left over flux. At least > that's been my experience. > Bingo. Was not doing a freon step, just IPA - am avoiding freon like ticks on sunny hillsides in the spring. Ugh. You might look at the H2O-clean solder - the 3 boards I scrubbed with distilled water and my old toothbrush yesterday look really nice - no gooey goopie mess. - danM -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

At 09:35 AM 7/18/00 -0600, you wrote: >James Paul wrote: FWIIW! FREON is a trademark, not a product. There is a whole family of FREON compounds, some good, some cursed, some refrigerants, some cleaners, some compass fluids and a myriad of other uses. FREON 12 is the old refrigerant which is alleged to be bad for the ozone layer. FREON-TF is the high quality de greasing solvent. Then there is FREON-TE, if my memory serves me, which was a FREON-alcohol blend and there was a FREON-?? which included a surfactant in the blend to help with cleaning. Current automotive refrigerants include FREON-134A. All these and many more share only the FREON trademark in common, they are physically and chemically different. Some are liquids at room temp and some are gasses. -Dan {Quote hidden}>> Quentin, >> >> I would suggest Freon and IPA (Isopropyl Alcohol). Use the FREON >> first. It will cut through the silicone spray rather well. After >> you get it pretty much clean with the Freon, use IPA to clean the >> Freon and the remaining silicone spray off. After this, it >> wouldn't hurt to wash the whole board in DI water if you have it >> available. If not, another wash with the IPA would be good. >> > >I thought freon was on the endangered species list nowadaze. > >Also, in my expert hands, IPA always leaves a nasty scum on the >pcb, which you then need another way to get rid of. > >- danM > >-- >http://www.piclist.com hint: The list server can filter out subtopics >(like ads or off topics) for you. See http://www.piclist.com/#topics > > - Dan Email: EraseMEdanbyonics.com See the GST-1 Converter for Earthmate GPS units at: http://www.byonics.com/gst-1 -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

In message <RemoveMEDA3A3E91471FD411B8D60000F8B82B3F44FBB7EraseMEEraseMEzpgtd00e.europe.norte> l.com>, Michael Rigby-Jones <RemoveMEmrjonesspam_OUTKILLspamNORTELNETWORKS.COM> writes >> At least it wasn't WD-40 >> >What's so bad about WD-40? ISTR it's only a light oil suspended in a >solvent. I'm pretty sure there are no sillicons in it after following a >thread on a car maintenance newsgroup. It wouldn't do much hard to a PCB, but I've had VCR's and cassette recorders where customers have sprayed WD-40 over all the mechanics, does wonders for belts and idlers etc. BTW, we just refuse to look at such items, and return them unrepaired!. -- Nigel. /--------------------------------------------------------------\ | Nigel Goodwin | Internet : RemoveMEnigelgTakeThisOuTspamlpilsley.co.uk | | Lower Pilsley | Web Page : http://www.lpilsley.co.uk | | Chesterfield | Official site for Shin Ki and New Spirit | | England | Ju Jitsu | \--------------------------------------------------------------/ -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

Dan Michaels wrote: >H2O-based flux, scrubbed with toothbrush, look clean What about under the parts ? I have had evil problems with stuff under SMD connectors and chips with other people's boards. Was that a SMT board ? Anyway I swear by rosin ... Peter -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

Peter Peres wrote: >Dan Michaels wrote: >>H2O-based flux, scrubbed with toothbrush, look clean > >What about under the parts ? I have had evil problems with stuff under SMD >connectors and chips with other people's boards. Was that a SMT board ? >Anyway I swear by rosin ... > The particular situation I was talking about was all thru-hole stuff. And actually, I was wondering about this situation myself, ie, with thru-hole soldering, why don;t you ever get much flux on the top of the board? I suspect solder being heavier sinks [assuming you're not soldering upside down], and flux floats. [would be nice if simple physics could explain something in electronics - just **once**]. However, on a side note, many board stuffer companies use h2o-clean solder now, and have a big washer that I assume sloshes water all over both surfaces of the pcb. So this should help get the flux out from under the smt devices. Possibly smt paste under the chips prevents other evil stuff from getting under there too. Hmmm, I wonder if paste is h2o-cleanable? Also, because of the slosh clean step, you do have to be a little careful with non-sealed parts, like trimpots. BTW, in my experience, sometimes the solder sticks and sometimes it doesn't - and it mainly has to do with how much garbage is on the surface of the component leads. Some parts come with nice clean leads, and others with nasty stuff on the leads. I was wondering if the board stuffers who use h2o-clean flux may go thru an extra pre-step of cleaning the leads before part insertion ?????? - danM -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

FWIW I found the same thing with IPA, my solution was to blow the IPA off the board (taking the scum with it) before it could evaporate. Still takes a couple of passes to clear up all the tidemarks. Worst case of ugly flux I saw was when I did rework on a board that had been soldered with a different flux originally. Big black tar-like mass surrounding the pad. Oliver. {Original Message removed}

Sometimes you can just chip that flux mess away with a sharp pick-like thing (dental pick, carbide scribe, solder tool, whatever.) Carefully, of course <G> Mark Oliver Broad wrote: > FWIW I found the same thing with IPA, my solution was to blow the IPA off > the board (taking the scum with it) before it could evaporate. Still takes a > couple of passes to clear up all the tidemarks. Worst case of ugly flux I > saw was when I did rework on a board that had been soldered with a different > flux originally. Big black tar-like mass surrounding the pad. > > Oliver. -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]: PIC only [EE]: engineering [OT]: off topic [AD]: advertisements

>persistent black flux You mean it was like amber ? ;-) Rosin flux is made of rosin which is also known as amber when dried clean. Also known for extremely good dielectric properties when dry (amber was used in early electrostatic experiments). Try to remove rosin based flux residue with acetone or paint thinner. Both attack plastic but both work well. Peter -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

Many years ago, I used to run an HP3000 system. HP distributed a periodical to their service people, which we occasionally saw (the periodical, not the people). I vividly remember one issue, where, in response to a question about what to do with a bunch of boards that had become contaminated from fire or flood, the response was to put them in a dishwasher with a good deionizing detergent. Dunno if it needed it. Hp included in its ads once the story about a unit that was found in the trunk of a stolen car that had been ditched in a river. The unit was returned to the factory, and, when dried out, found not only to be functional, but still in calibration. HP tended to be very practical in service matters. The 3000 was intermittent -- one of the first ones -- and, after a month or so of excessive downtime, we got a call from the tech, who said that the factory had found the problem, and he would stop by after getting the repair tool. An hour later, he showed up, opend up the cabinet, and pulled a claw hammer out of his toolkit. He put the handle on each board in turn, and swatted the head with his hand, thus firmly seating said board... Mike Mullen -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.