Soldering iron correct choice of flux
When soldering with an electric soldering iron, in addition to always having a solder bar as solder, which is directly used for soldering, flux should also be prepared. Flux aids in soldering and improves soldering quality. There are three main functions of flux:
One is to remove the oxide layer and dirt, and suspend the slag on the surface of the welding joint;
The second is to transfer the welding heat to the material to be welded, reduce the surface tension of the solder, and improve the lubricating ability;
The third is to provide an active or protective gas to prevent the volatilization of high-temperature gas elements in the solder, prevent the formation of oxides, and make the solder joints more perfect. Commonly used fluxes include rosin, rosin alcohol solution (40% rosin, 60% alcohol), solder paste and hydrochloric acid (adding an appropriate amount of zinc can only be used after chemical reaction), etc. Among them, rosin is a natural resin with little corrosion, which is suitable for welding components such as electronic circuits and small-diameter wire ends.
Solder bar (also known as solder wire) contains rosin, so it is commonly known as rosin core solder bar. Rosin alcohol solution is suitable for welding small-diameter wire ends and small-capacity components in the field of strong electricity. Solder paste (commonly known as solder oil) is a good flux, but it is relatively corrosive and not an insulator itself, so it is not suitable for welding radio components. It is mostly used for welding large metal components. Do not use too much. Hydrochloric acid is suitable for tinning on the connection surface of steel components or connection welding of steel components. Since various fluxes have different corrosive effects, after welding, alcohol cotton balls should be used to clean the welding parts to prevent residual flux from corroding solder joints and welded parts, which will affect the quality and service life of the product.
