If you can't find one lying around your dad's workbench, the local hardware store sells them for a few bucks apiece.

The requirement of the cleaning level is more than the water on metal, for there must be close bonding between solders and metals.

Solder paste residues, which remain in fine-pitch apertures after manual cleaning, cause inconsistent print images and thus can lead to bridges and solder balling between solder joints.

The minor lead would be found in lead-free solder rods after using them, then it makes the lead contaminant for the electronic components.

This paper proceeded the analysis for the problems that appear in actual application of the soldering paste , which is of some value to SMT technicians.