What is the primary purpose of flux in soldering?

Flux plays a crucial role in the soldering process by removing oxides from metal surfaces. When metals are heated, they can form an oxide layer that inhibits the proper adhesion of solder. The presence of these oxides prevents a strong bond from forming between the metals being joined, which could lead to a weak solder joint or failure of the connection.

By using flux, the oxides are cleaned off the surfaces, allowing the solder to properly wet and adhere to the metal. This is essential for achieving a reliable and durable connection. The effectiveness of soldering relies heavily on the cleanliness of the metal surfaces, and flux ensures that they are adequately prepared for the solder to flow and bond.

Additionally, while flux can have roles related to preventing corrosion and enhancing the flow of solder, its primary and most vital function is the removal of oxides to facilitate better soldering outcomes.