Selection of soldering iron and soldering methods
When we choose an electric soldering iron, it is generally determined by the size of the solder joint. If the solder joint area is large, the heat dissipation speed will be faster, so the electric soldering iron we choose has a faster heating speed and a higher power. The power of our commonly used soldering irons is 20W, 25W, 30W, 35W, 50W and so on. It is more appropriate to choose a power of about 30W. Here, the editor uses a soldering iron table, the one in Figure 1. The heating temperature can be adjusted at any time, which is convenient, but it is inconvenient to carry. The one in Figure 2 is easy to carry, but the heating is unstable.
Soldering tip
When the soldering iron is used for a long time, the soldering iron tip will generate a layer of oxide, which is not easy to tin. We can file off the oxide layer or use a knife to scrape it off. Then turn on the soldering iron and heat it slightly. You can apply rosin, and then apply solder.
Solder and flux
When we choose solder, we should use 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. Of course, there is also a solder wire containing rosin on the market. It's very easy for us to use.
Note: A new soldering iron must be rosinized the first time it is used.
Solder remover and dirt removal sponge
Purpose of solder suction device: It is used to suck out excess soldering wire and disassemble electronic components.
The purpose of the decontamination sponge: When using it, soak it in clean water. It is mainly used to remove dirt on the soldering iron tip and make the soldering iron easier to solder. Use it to clean the soldering iron tip after using the soldering iron.
5. Welding method
Action essentials: heat first and then deliver tin, remove tin first and then remove the soldering iron.
When electronic components are being stored, due to the oxidation of air, a layer of oxide film is attached to the component pins, as well as other dirt. Before welding, we must clean the components and coat them with a layer of tin. In this way, the solder joints we weld will be less likely to have virtual soldering.
Welding temperature and welding time
We should choose the appropriate temperature when welding. The temperature can be higher than the temperature of the solder. If it is too high, it is not good. In serious cases, the solder pad will fall off directly. 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 number of tinned solder joints
We must control the amount of tin on the solder joints. The amount of solder on the solder joints should not be too small. If it is too little, the welding will not be strong, the solder joints will be flat, and the mechanical strength will be too poor. If there are too many, it will easily cause a lot of them on the outside but not connected on the inside, forming a bucket shape, which is extremely ugly. The solder should just immerse all the component pins on the soldering point, and the outline should be vaguely visible.
