Flux

Flux is a chemical made from natural or synthetic resin that is used to improve solder joints. Flux cleans the surface of the metal and helps solder flow better (a characteristic called “wetting”). This helps ensure that soldered conductors are firmly and permanently joined together.

Although flux is very important to creating strong solder joints, the use of flux has some drawbacks. Most importantly, flux is very corrosive, and flux residue can damage components over time. Cleaning excess flux is a difficult task because it is very sticky. When heated, it melts and spreads into inaccessible areas, such around the individual conductors of stranded cable. Today, no-clean fluxes are used whenever soldering stranded cable and other components that can’t be completely cleaned of flux.

Because flux is so important to the construction of electronic circuits, the types of flux that Wurlitzer used in its factories is an important factor in the overall assembly procedures of electronic parts.