An introduction to the main points of welding with an electric soldering iron
1. Selection of soldering iron The power of the soldering iron should be determined by the size of the solder joint. The solder joint has a large area and the heat dissipation speed of the solder joint is also fast, so the power of the soldering iron selected should also be larger. The power of general electric soldering irons is 20W, 25W, 30W, 35W, 50W, etc. It is more appropriate to choose a power of about 30W. After the electric soldering iron is used for a long time, a layer of oxide will be formed on the head of the soldering iron. At this time, it will not be easy to eat tin. At this time, you can use a file to remove the oxide layer. After the soldering iron is powered on, insert rosin when the head of the soldering iron is slightly hot. , apply solder and you can continue to use it. The newly purchased soldering iron must also be tinned before it can be used.
2. For soldering and flux, choose low melting point solder wire and non-corrosive flux, such as rosin. It is not suitable to use industrial solder and corrosive acidic soldering 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 tin-plated. When electronic components are being stored, due to the oxidation of air, there will be an oxide film on the component pins, as well as other dirt. Before welding, you can use a knife to scrape off the oxide film and apply it immediately. A layer of solder (commonly known as tin enamel), and then soldering. After the above treatment, the components are easily soldered firmly and the phenomenon of false soldering is less likely to occur.
Welding temperature and welding time When welding, the temperature of the electric soldering iron should be higher than the temperature of the solder, but not too high. It is better to just smoke when the soldering iron tip touches the rosin. If the welding time is too short, the temperature of the solder joints will be too low, the solder joints will not melt sufficiently, and the solder joints will be rough, which can easily lead to false soldering. On the contrary, if the welding time is too long, the solder will flow easily, and the components will easily be overheated and damaged.
The amount of tin on the soldering point should not be too small. If it is too small, the welding will not be strong and the mechanical strength will be too poor. And too much can easily cause a lot of things on the outside but not connected on the inside.
The solder should just immerse all the component pins on the soldering point, and the outline should be vaguely visible.
Pay attention to the position of the soldering iron and the soldering point. When welding, beginners usually move the soldering iron back and forth on the soldering point or squeeze it hard. This method is wrong. The correct method is to use the tin-lined surface of the soldering iron to contact the soldering point, so that the heat transfer area is large and the soldering speed is fast.
4. Inspection after welding. After welding, it is necessary to check whether there are missing solders, weak solders, or component short circuits caused by solder flow. Welding is difficult to detect. You can use tweezers to hold the component pins and gently pull them. If shaking is found, repair the soldering immediately.
