PCB Cleaning after Soldering

[chopnhack]

How do you clean your PCB's after soldering? If you were preparing to spray a conformal coating?

I was thinking of using the coating to prevent oxidation for one of my projects that will be in a harsh environment. To prepare for the coating, the substrate needs to be clean and free of residue from soldering. My thoughts are to use alcohol and a toothbrush followed by a deionized water wash. Blow dry with compressed air.

Your thoughts?

 

[KJ6EAD]

Use whatever flux removal method works with your flux, including mechanical action such as brushing. This may be a water based process or other. Follow any water rinses with compressed air then alcohol to scavenge the remaining water. Blow off again and bake in a low temperature oven.

 

[chopnhack]

Use whatever flux removal method works with your flux, including mechanical action such as brushing. This may be a water based process or other. Follow any water rinses with compressed air then alcohol to scavenge the remaining water. Blow off again and bake in a low temperature oven.

Awesome, thanks for the input - low temp oven would easily and quickly evaporate the alcohol, good thinking

 

[Bluejets]

Mineral turps seems to remove residual flux quickly.

 

[KJ6EAD]

low temp oven would easily and quickly evaporate the alcohol

More importantly, it will evaporate it completely so no hidden pocket of liquid trapped in or under a component can cause a thin spot or bubble in the conformal coating.

 

[chopnhack]

Mineral turps seems to remove residual flux quickly.

Interesting, I had not thought of using that as a solvent - I thought it would leave a oily residue for some reason...

More importantly, it will evaporate it completely so no hidden pocket of liquid trapped in or under a component can cause a thin spot or bubble in the conformal coating.

Again, good point, especially since I have vias all over the intended board! Thanks again.

I have read 170F was a good temp, any information from your experience?

 

[KJ6EAD]

That's fine. You should of course familiarize yourself with the best practices recommended by the manufacturer of your conformal coating.

 

[davenn]

Mineral turps seems to remove residual flux quickly.

yeah, but leaves a greasy mess, that you then have to use some other cleaner to get rid of

there are proper spray on (canned) flux removal products

this is the one I have used for many years ....
http://www.bing.com/images/search?q...EDF89D936CFA0259A9F632BC136A0&selectedIndex=0

Dave

 

[Daniel Robertson]

Cellulose thinners for me every time.

 

[jack20140512]

two methods when clean the residue flux, one is use alcohol and a toothbrush. the Alcohol must be standard industy or the PCB will became white. the other is to use Ultrasonic machine. but some of the parts may be damaged