WS containing soluble halides have been available for several decades.
There are among the most commercially develops flux available with chemical activity tailored over a wide range , roughly in proportion to the total halide content.
Perticular care need to be taken to clean off ionic residues , which can cause corrosion and generate electrical malfunction.
WS tent to have shorter printing life than rosin , have less tackiness and are therefore more difficult to use for reflow soldering.