Usage of electric soldering iron rosin
Rosin serves as a soldering flux in welding, playing a soldering role. In theory, the melting point of flux is lower than that of solder, and its specific gravity, viscosity, and surface tension are all lower than that of solder. Therefore, during welding, the flux melts first, quickly flows and covers the surface of the solder, isolating air and preventing metal surface oxidation. It can react with the surface oxide film of solder and the soldered metal at high temperatures during welding to melt and restore a pure metal surface. Suitable soldering tin helps to produce a satisfactory solder joint shape and maintain the surface gloss of the solder joint.
Rosin is the most commonly used soldering flux, which is neutral and does not corrode circuit components and soldering iron tips. If it is a newly printed circuit board, a layer of loose perfume should be coated on the surface of the copper foil before welding. If the circuit board is already made, it can be directly soldered. In fact, the use of rosin depends on personal habits. Some people immerse the soldering iron head on the rosin every time they weld a component; I always soak some rosin on the electric soldering iron when it is oxidized and inconvenient to use. The use of rosin is also very simple. Open the rosin box and soak the powered soldering iron tip on it. If solid solder is used during welding, adding some rosin is necessary; If rosin tin wire is used (with flux wrapped inside the wire core), rosin may not be used.
Due to the formation of an oxide film on the metal surface after contact with air, the higher the temperature, the more severe the oxidation. This oxide film prevents the wetting effect of liquid solder on the metal, just like oil on glass prevents water from wetting. Flux is a specialized material used to remove oxide films, also known as flux.
Flux has three main functions:
1. Remove the oxide film. The essence is that the substances in the flux undergo a reduction reaction, thereby removing the oxide film. The reaction products become suspended slag, which floats on the surface of the solder.
2. Reducing surface tension and increasing the flowability of solder can help wet solder components.
3. Prevent oxidation. After melting, it floats on the surface of the solder, forming an isolation layer, thereby preventing oxidation of the welding surface.
