Soldering flux is (or at least, should be) one of the ubiquitous features of any electronics bench. It serves the purpose of excluding oxygen from a solder joint as it solidifies, and in most ...

Solder metal fills this gap by capillary action ... A slight twisting motion ensures even coverage by the flux. Remove excess ...

Now Pi boards have their tiny bits and bigger pieces soldered at the same time through an intrusive reflow soldering process ...

But it’s certainly more than enough to see any gross problems lying below a BGA, like shorts or insufficiently melted solder. [Petteri] reports that flux can be a problem, too, as excess of the ...

To avoid this, use a rosin flux on the wire strands you solder together ... Finish up by cleaning off excess dielectric paste.