Re: PCB Cleaning

[K3yPr0gg3r]

Hi,

I'm just wrapping up a J-Standards soldering class I took prior to beginning my DIY pedal making endeavor. I'm not sure if I'm repeating a previous post or not, so I apologize in advance if I am. My instructor stressed the importance of cleaning an "area" prior to and immediately after soldering. He recommended IPA, (90% - 99%), for cleaning. He stated there's a fungus that can literally eat a PCB away that comes from the oils of our hands, environmental contaminants that can destroy boards and components over time, etc. I'd like to give my creations as long a life as possible so I guess my question is this. Do most builders use IPA for cleaning or are the board cleaning products out there that I am not aware of that are superior?
Thank you

[EBRAddict]

Not grocery-store IPA, use "technical grade" 99.9% anhydrous isopropyl. Use it to clean the board, component legs, contacts.

http://www.frys.com/product/3936318

If you want to be hardcore wear surgical gloves while building. I don't, it's too much of a hassle.

A good quality flux solder like Kester has anti-corrosive compounds in the flux. Leaving it on the board is probably better than cleaning it off and leaving the board bare. When I used to build boards for the army we'd always remove the flux and coat them with several coats of poly sealant but those boards had to meet environmental exposure standards which no pedal ever would.

[pickdropper]

IPA definitely works, but it can leave the board sticky after the first pass.  You can get the stickiness to go away, but it usually takes a few passes.

Flux remover gets the flux off more effectively, but it's a little bit more expensive.  I've used this one; it's less expensive than most and still works well:

http://frys.com/product/6713615?site=sr:SEARCH:MAIN_RSLT_PG

[rullywowr]

IPA definitely works, but it can leave the board sticky after the first pass.  You can get the stickiness to go away, but it usually takes a few passes.

Flux remover gets the flux off more effectively, but it's a little bit more expensive.  I've used this one; it's less expensive than most and still works well:

http://frys.com/product/6713615?site=sr:SEARCH:MAIN_RSLT_PG

I agree.  If I do clean PCBs after soldering, I use isopropyl alcohol 91% and alternate with Simple Green to help remove all the sticky stuff left behind.

These days I mainly use "no clean" Kester solder and no clean flux and don't worry about cleaning anything.

[K3yPr0gg3r]

Thanks for all the posts! I'll have to try this Kester solder.

[davent]

I think i read of Leevibe adding a touch of dish detergent to the IPA to deal with the sticky residue caused by the cleaning.

dave

[Orbis_Ignis]

I have never don't this. Is it necessary???

[galaxiex]

I have never don't this. Is it necessary???

"Probably" not...

Some circuits are sensitive to "leakage" due to the conductive nature of flux residue.

Leftover (un-cleaned) flux can absorb moisture and cause voltage/current leakage
from one part of the circuit to another, where there should not be *any* connection.

This is very critical in RF (radio frequency) circuits where you are dealing with very high frequencies.

I was involved with Radio Control model aircraft where I had a strange control problem with my transmitter.
I eventually tracked it down to uncleaned flux residue in the high frequency RF section of the transmitter.

Simply giving the circuit board a good 2X scrubbing with a commercial flux cleaner resolved the issue.

To repeat; for guitar pedal circuits it probably won't matter,
but it certainly will not hurt to clean the board of all flux after soldering.
Makes for a nice neat (pro) looking build. 

[peterc]

This is the stuff I use and it works fine

http://www.mantech.co.za/ProductInfo.aspx?Item=90M0053

[dont-tase-me-bro]

The mg chemicals flux remover aerosol works good.  although not essential, I prefer using it outside if possible because it stinks up my garage

[pickdropper]

The mg chemicals flux remover aerosol works good.  although not essential, I prefer using it outside if possible because it stinks up my garage

Yep on both counts.  MG Chemicals, like most commercial flux removers, works really well, but has some powerful solvents in it that aren't all that good for your health.  One of the ones I ran across a while back actually had n-hexane in it, which should be used with caution (that's the one that got Apple in trouble when workers exposed to it got sick).