How to clean pcbs after soldering?

[kawayanstrat]

How do you clean PCBs after soldering? Seem like brushing it off wont do. Please help!

[R.G.]

rubbing alcohol

[jefe]

Are we talking about the flux? Is it really necessary to clean the boards after soldering?

[kawayanstrat]

rubbing alcohol

Thanks i will try.

[Mark Hammer]

1) Methyl hydrate on the end of a Q-tip (cotton-tipped swab/applicator) does wonders.  Works much better than rubbing alchohol, and with less stink.  I know.  I used the one for years, and started using the other because I ran out of the stuff I usually used.  I will NEVER switch back again.

2) You don't NEED to remove the flux, but it sure helps in being able to clearly see what is and isn't a solder bridge.  The flux does not prevent the circuit from working, but it creates "visual noise" that makes inspection of the board for imperfections (solder bridges, gaps, cold joints) difficult.

[jefe]

2) You don't NEED to remove the flux....  The flux does not prevent the circuit from working...

OK, that's what I thought. Thanks Mark.

[bumblebee]

eucalyptus oil on a cotton tip seems best to me.

[drewl]

There used to be great toxic stuff for cleaning in the old days, but in todays world Denatured Alcohol is the safe way.
We had some tubes of great flux remover at work but I think I used it all.

[tranceracer]

acetone works well too.

[John Lyons]

Acetone will work but it's kind of like killing a fly with a sledge hammer.
Denatured Alcohol or Isoprop Alcohol works well.
Usually I just scrap off the bigger bits of flux with a meter probe or sharp tool.

If there is a lot of flux left between solder joints it will atract water vapor and possibly lead to capacitive coupling and "funny stuff".
It's happend..ask Paul Marrossy, he posted a debug here somewhere where the flux was the only problem and after it was removed the circuit came back to life.

[juse]

If you use water-soluble flux then you can use an acid brush and warm water to clean it. Of course it doesn't hurt having a heated ultrasonic water tank at work either 

[jpm83]

Could this stuff be used for cleaning off flux. http://www.motip.nl/?page=23&id=760

Janne

[MikeH]

2) You don't NEED to remove the flux....  The flux does not prevent the circuit from working...

I thought I heard that after a very long time flux can absorb moisture and become conductive causing poor or non-operation.  True?

[jefe]

Usually I just scrap off the bigger bits of flux with a meter probe or sharp tool.

That's what I've been doing - I inspect each solder joint as I go (under magnification), looking for solder bridges, and I scrape off the flux between joints with a sharp tool. BUT - I'm still fairly new to building effects. Over the years, I have never bothered to remove flux when installing a car stereo, soldering up speaker wires, etc.

[fluoreszenz]

2) You don't NEED to remove the flux, but it sure helps in being able to clearly see what is and isn't a solder bridge.  The flux does not prevent the circuit from working, but it creates "visual noise" that makes inspection of the board for imperfections (solder bridges, gaps, cold joints) difficult.

Hammer is right ... plus


one particularly difficult problem is presented by residual flux.

Those contaminations may remain near a solder connection or elsewhere on the pcb. 

When we consider that one of the functions of flux is to remove oxidation on metal surfaces within solder connections,

one can understand that there is a certain potential for chemical reaction or corrosion of other metal surfaces.

Resulting corrosion through these contaminations can cause failure of a component long after it is placed in service.



You may remove residual fluxes with a flow of slightly warmed up solvents (+ in an ultrasound bath)

[jefe]

You may remove residual fluxes with a flow of slightly warmed up solvents (+ in an ultrasound bath)

No offense sir, but how is the common DIY'er supposed to do that? This sounds like severe overkill, IMO. This is something that is done in a factory, on a production line.

So far, the easiest and least toxic method presented in this thread appears to be alcohol on a cotton swab. Do we really need to go further than that? In my humble opinion, no. We aren't building aircraft or nuclear power plants here, we're building guitar effects. What's the worst that could happen? My wah pedal stops wahing?

[fluoreszenz]

ultrasonic bath is overkill, without a doubt in DIY...   

and i'm not sure if the OP is aware of such a method

[ayayay!]

Flux Off.  I use it everyday.

http://www.stanleysupplyservices.com/product-group.aspx?id=983

[skiraly017]

ultrasonic bath is overkill, without a doubt in DIY...   

and i'm not sure if the OP is aware of such a method

I bought an ultrasonic cleaner for I think $20 at an electronics overstock place (I want to say Electronic Goldmine) although it's still sitting in the box in my closet. Also I've found that the Radio Shack Contact Cleaner Pen (RS Cat No. 64-4341) works very well, use an old toothbrush for heavier residue if needed.

[Naz Nomad]

Flux Off.

... charming