The key points of electric soldering iron welding are introduced as follows:
1. Selection of electric soldering iron
The power of an electric soldering iron should be determined by the size of the solder joint. The area of the solder joint is large, and the heat dissipation speed of the solder joint is also fast. Therefore, the power of the selected electric soldering iron should also be higher. The power of a general electric soldering iron is 20W, 25W, 30W, 35W, 50W, and so on. Choosing a power of around 30W is more appropriate.
After prolonged use, a layer of oxide will form on the tip of an electric soldering iron, making it difficult for it to eat tin. In this case, you can use a file to remove the oxide layer, turn on the soldering iron, and when the tip is slightly hot, insert rosin and apply solder to continue using it. Newly purchased electric soldering irons must also be tinned before use.
2. Solder and flux
Choose low melting point solder wire and non corrosive flux, such as rosin. It is not advisable to use industrial solder or corrosive acidic solder oil. It is best to use solder wire containing rosin, which is very convenient to use.
3. Welding method
The components must be clean and tinned. During storage, electronic components may have a layer of oxide film attached to their pins due to air oxidation, as well as other dirt. Before welding, a small knife can be used to scrape off the oxide film and immediately apply a layer of solder (commonly known as tin coating) before welding. After the above treatment, the components are easy to solder firmly and are not prone to false soldering. Welding temperature and welding time
When welding, the temperature of the electric soldering iron should be higher than the temperature of the soldering tin, but it should not be too high, and it is better for the soldering iron tip to just come into contact with rosin and smoke. If the welding time is too short, the temperature of the solder joint is too low, the melting of the solder joint is not sufficient, and the solder joint is rough, it is easy to cause virtual soldering. Conversely, if the welding time is too long, the solder is prone to flow, and it is easy to cause overheating and damage to the components.
The number of tin applied to the solder joint
The amount of solder on the welding point should not be too small, as it may not be firmly soldered and the mechanical strength may be poor. And too much can easily cause a lot of appearance and internal disconnection. Soldering should just submerge all the pins of the components on the solder joint, and the outline should be vaguely visible.
Pay attention to the position of the soldering iron and welding points
Beginners generally move the electric soldering iron back and forth or squeeze it forcefully at the welding site when welding, but this method is incorrect. The correct method is to use the tinned surface of an electric soldering iron to contact the welding point, which has a large heat transfer area and a fast welding speed.
4. Inspection after welding
After welding is completed, it is necessary to check for any solder leaks, false soldering, and component short circuits caused by solder flow. Virtual soldering is difficult to detect, so you can use tweezers to clamp the component pins and gently pull them. If any shaking is found, it should be repaired immediately
