The basic points of electric soldering iron welding are introduced:
1. Selection of electric soldering iron The power of the electric 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 electric soldering iron should also be larger. Generally, the power of the electric soldering iron is 20W25W30W35W50W and so on. It is more appropriate to choose a power of about 30W. 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 should use low-melting solder wire and non-corrosive flux, such as rosin. Industrial solder and corrosive acidic solder oil should not be used. It is better to use solder wire containing rosin, which is very convenient to use.
3. Soldering method Components must be cleaned and tinned. Electronic components are in storage. Due to the effect of air oxidation, there is a layer of oxide film on the component pins, and there are other dirt. Before welding, the oxide film can be scraped off with a knife and coated immediately. A layer of solder (commonly known as enamel tin), and then soldering. After the above treatment, the components are easy to weld firmly, and the phenomenon of virtual welding is not easy to occur.
Soldering temperature and soldering 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 and just smokes. 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.
The amount of tin on the soldering point The amount of soldering tin on the soldering point should not be too small, if it is too small, the soldering 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.
Pay attention to the position of the soldering iron and the soldering point. When soldering, beginners usually move the soldering iron back and forth or squeeze the soldering point hard. 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 soldering After soldering, it is necessary to check whether there are missing soldering, virtual soldering and component short circuit caused by solder flow. Welding is difficult to find, you can use tweezers to hold the component pins and pull it gently, if you find shaking, you should repair the soldering immediately
