Summary of the main points of electric soldering iron welding technology
1. Selection of electric soldering iron
The power of the soldering iron should be determined by the size of the soldering point. The area of the soldering point is large, and the heat dissipation speed of the soldering point is also fast, so the power of the soldering iron should be larger. Generally, the power of the electric soldering iron is 20W 25W 30W 35W 50W and so on. It is more appropriate to choose a power of about 30W during the production process.
After the electric soldering iron has been used for a long time, a layer of oxide will be formed on the tip of the soldering iron. At this time, it is not easy to eat tin. At this time, you can use a file to file off the oxide layer. After the soldering iron is powered on, insert the rosin when the tip of the soldering iron is slightly hot. , You can continue to use it after applying solder, and the newly bought electric soldering iron must be tinned before it can be used.
2. Solder and flux
Choose solder wire with low melting point and non-corrosive flux, such as rosin. It is not suitable to use industrial solder and corrosive acid solder oil. It is better to use solder wire containing rosin, which is very convenient to use.
3. Welding method
Components must be cleaned and tinned. Electronic components are kept in the air. Due to oxidation, a layer of oxide film is attached to the component pins, and there are other dirt. Before soldering, the oxide film can be scraped off with a knife, and a layer should be applied immediately. Solder (commonly known as enamel), and then solder. After the above treatment, the components are easy to weld firmly, and the phenomenon of virtual welding is not easy to occur.
(1) Welding temperature and welding time
When soldering, the temperature of the electric soldering iron should be higher than the temperature of the solder, but it should not be too high. It is better that the soldering iron tip contacts the rosin just before smoking. If the soldering time is too short, the temperature of the solder joints is too low, the solder joints are not fully melted, and the solder joints are rough and easy to cause false soldering. On the contrary, the soldering time is too long, the solder is easy to flow, and it is easy to cause the components to overheat and damage the components.
(2) The amount of tin on the soldering point
The amount of solder 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 is easy to cause a lot of appearance but not connected inside. The solder should just submerge all the component leads on the soldering point, and the outline should be faintly visible.
(3) Pay attention to the position of the soldering iron and soldering point
When beginners solder, they usually move the soldering iron back and forth or squeeze hard at the soldering place. This method is wrong. The correct method is to use the tin-coated surface of the electric soldering iron to touch the soldering point, so that the heat transfer area is large and the welding speed is fast.
4. Inspection after welding
After soldering, it is necessary to check whether there are missing soldering, virtual soldering, and component short circuits caused by solder flow. False soldering is difficult to find, you can use tweezers to clamp the component pins and pull it gently, if you find shaking, you should repair the soldering immediately.
