The selection and welding method of electric soldering iron
1. Selection of electric soldering iron
When choosing an electric soldering iron, it is generally determined by the size of the welding points. If the area of the welding points is large, the heat dissipation speed is also fast. Therefore, the electric soldering iron chosen has a faster heating speed, which means a higher power. We commonly use electric soldering irons with powers of 20W, 25W, 30W, 35W, 50W, and so on. Choosing a power of around 30W is more appropriate. Here, the editor uses a soldering iron table, which is the type shown in Figure 1. The heating temperature can be adjusted at any time, which is convenient, but inconvenient to carry. The one in Figure 2 is convenient to carry, but the heating is unstable.
2. Soldering iron tip
After long-term use, an electric soldering iron will generate a layer of oxide on the tip, which is not easy to solder. We can file off the oxide layer or use a small knife to scrape it off. Then, turn on the electric soldering iron and heat it slightly to apply rosin. Then, we can apply soldering tin.
3. Solder and flux
When choosing solder, we should use low melting point solder wire and non corrosive flux, such as rosin. Industrial solder and corrosive acidic solder oil are not suitable. Of course, there is also a type of solder wire containing rosin on the market, which makes it very convenient for us to use.
Rosin must be added on the first use.
4. Tin absorber and cleaning sponge
The purpose of a solder absorber is to remove excess solder wire and disassemble electronic components.
The purpose of cleaning sponge: When using, it should be soaked in clean water. It is mainly used to remove dirt on the soldering iron head, making it easier for the soldering iron to tin. After using the soldering iron, use it to clean the soldering iron head.
5. Welding method
Action tips: Heat first and then send tin, remove tin first and then remove soldering iron.
During the storage of electronic components, due to the oxidation of air, a layer of oxide film is attached to the pins of the components, as well as other dirt. Before welding, we need to clean the components and coat them with a layer of tin. In that way, the solder joints we weld together are less likely to have virtual soldering.
Welding temperature and welding time
When welding, we should choose an appropriate temperature, which should be higher than the temperature of the solder. If it is too high, it is not good. In severe cases, the solder pad may fall off directly. It is better to let the soldering iron tip come into contact with rosin and smoke just now.
Welding time is too short, the temperature of the welding points is too low, the melting of the welding points is not sufficient, and the welding points are rough and easy to be rough
Causing virtual soldering, conversely, if the soldering time is too long, the solder is prone to flow and can easily cause overheating and damage to the components.
The number of tin applied to the solder joint
We need to have a good grasp of the amount of solder applied to the solder joints. The amount of solder applied to the solder joints should not be too small, as it may not be firmly soldered and the solder joints may be flat, resulting in poor mechanical strength. If there are too many, it is easy to cause a pile of appearance but the interior is not connected, forming a bucket shape, which is extremely ugly. Soldering should just submerge all the pins of the components on the solder joint, and the outline should be vaguely visible.
