What is Active Flux in Soldering?

What is Active Flux in Soldering?

Active flux in soldering refers to a type of flux that contains chemical agents designed to remove oxides and other contaminants from the surfaces being soldered. It is called “active” because it actively reacts with the metal surfaces, promoting wetting and improving the soldering process.

Active fluxes typically contain rosin or organic acids, such as hydrochloric acid or citric acid, which help dissolve oxides and create a clean surface for soldering. These fluxes are commonly used in electronics and plumbing applications, where a strong bond between the solder and the metal is required.

When heated, the active flux becomes active and starts to remove the oxides from the metal surfaces, allowing the solder to flow and bond effectively. After soldering, it is important to clean the flux residue from the joint to prevent corrosion and ensure the long-term reliability of the soldered connection.

It’s worth noting that active fluxes can be more aggressive compared to other types of fluxes, so it’s important to use them appropriately and follow safety guidelines when working with them.