What is the function of rosin in soldering iron?
In the past few days, I often see people asking why rosin is added to solder. Here is a rough summary. Rosin is the most commonly used flux and is neutral. If it is a newly printed circuit board, apply a layer of rosin water to the surface of the copper foil before soldering. If the circuit board is already made, it can be soldered directly. In fact, the use of rosin depends on personal habits. Some people will dip the soldering iron tip in rosin after soldering a component. The use of rosin is also very simple. Just open the rosin box and dip the powered soldering iron tip in it. If solid solder is used during welding, adding some rosin is necessary; if rosin tin soldering wire is used, rosin is not required.
The role rosin plays when soldering. Rosin will be slightly acidic at the temperature of the soldering iron, which can clean the oxide layer on the welding surface, allowing the solder to infiltrate the welding surface. Nowadays, the solder used in the electronic industry generally has rosin in the middle. Just put some on the soldering iron, and the soldering wire can be directly pressed against the soldering iron. The types of flux can be roughly divided into three series: organic, inorganic and resin. Resin flux is usually extracted from the secretions of trees. It is a natural product and is not corrosive. Rosin is the representative of this type of flux, so it is also called rosin flux. Because flux is usually used in conjunction with solder, it can be divided into soft flux and hard flux corresponding to solder. Soft fluxes such as rosin, rosin mixed flux, solder paste and hydrochloric acid are commonly used in the assembly and maintenance of electronic products. In addition, they should be selected according to different welding workpieces in different occasions. When using flux, you must apply an appropriate amount according to the area and surface condition of the parts to be welded. If the amount is too small, it will affect the welding quality. If the amount is too much, the flux residue will corrode the components or worsen the insulation performance of the circuit board.
