Technical points of electric soldering iron welding
Soldering the components on the circuit board with an electric soldering iron is a basic and necessary skill for electronic and electrician technicians. Both repairing and assembling breadboards require solid manual soldering skills. The welding experience in practice is now summarized for reference by those in need.
1. The basic principle of welding
The full name of soldering we use should be tin brazing, which is to use molten solder to bond two non-melting metal surfaces together. The basic principle is to use the molten solder to infiltrate other metal surfaces at high temperature, so that the part where the solder and the metal surface are in contact forms a solid alloy, which is welded together under cooling. For a detailed introduction to brazing, please search for relevant information online.
2. Conditions for good welding
The formation of a good solder joint requires three conditions: a clean soldering surface, a suitable temperature and an appropriate amount of flux.
If you are welding old components, the pins have been oxidized, and the oxide layer needs to be cleaned.
The soldering temperature should not be too low. If the temperature is low, it will affect the leveling of the solder, resulting in rough solder joints, rough shapes and even burrs. Generally, electric soldering irons do not have a constant temperature function, and the soldering temperature is indirectly controlled by controlling the soldering time, which requires some experience in practice.
Flux generally uses rosin, do not use solder paste, because solder paste has a corrosive effect on the circuit board. Using rosin will not corrode the circuit board. If it is not too ugly, you don't need to clean it after soldering.
3. Treatment of new electric soldering iron
Generally used internal heating type electric soldering iron, the tip of the new soldering iron should be tinned before use. The purpose of tinning is to improve the heat conduction speed of the electric soldering iron. If it is not tinned, the tip of the soldering iron will be oxidized as soon as it is heated, and the heat transfer efficiency of the oxide layer is very low, which will seriously affect the welding effect, and even cause the phenomenon that the soldering cannot be done.
The method of tinning the soldering iron:
1. Prepare a piece of rosin and solder wire.
2. Put the tip of the soldering iron against the rosin, and turn on the electricity to heat. As the temperature of the soldering iron tip rises, the rosin will melt. At this time, the soldering iron tip should be moved continuously so that the soldering iron tip is wrapped by the rosin liquid and kept from contact with the air.
3. When the temperature reaches the melting temperature of the solder, use the solder wire to rub back and forth on the tip of the soldering iron, so that the entire tip of the soldering iron is evenly covered with solder.
4. Power off and cool down. After the tinning is completed, it can be used normally in the future.
