The correct welding method for electric soldering iron should be the five step method:
1. Prepare for welding
Prepare the soldering wire and soldering iron. At this point, it is particularly emphasized that the head of the soldering iron should be kept clean, that is, it can be coated with solder (commonly known as eating tin).
2. Heating welding parts
When placing the soldering iron in contact with the solder joint, it is important to first keep the soldering iron heating all parts of the solder joint, such as the leads and pads on the printed circuit board. Secondly, it is important to ensure that the flat part (mostly) of the soldering iron head contacts the solder joint with a larger heat capacity, and the side or edge of the soldering iron head contacts the solder joint with a smaller heat capacity to ensure even heating of the solder joint.
3. Melting solder
When the solder is heated to a temperature that can melt the solder, place the welding wire at the solder joint, and the solder begins to melt and wet the solder joint.
4. Remove the solder
After melting a certain amount of solder, move the solder wire away.
5. Remove the soldering iron
When the solder completely wets the solder joint, remove the soldering iron. Note that the direction of removing the soldering iron should be approximately 45 °.
The above process takes about two to three seconds for a typical solder joint. For solder joints with smaller heat capacity, such as small pads on printed circuit boards, the three-step method is sometimes used to summarize the operation method, which combines steps 2 and 3 into one step and steps 4 and 5 into one step. In fact, the subtle distinction is still five steps, so the five step method is universal and is the basic method for mastering manual soldering iron. Especially the time spent between each step is crucial for ensuring welding quality, which can only be gradually mastered through practice
