Prepare materials and tools: soldering wire, soldering iron, welding parts.
Step 1: Prepare the solder wire and soldering iron. At this time, it is especially emphasized that the head of the soldering iron should be kept clean, that is, it can be stained with solder (commonly known as eating tin).
Step 2: Contact the soldering point with the soldering iron, taking care to first hold the soldering iron heating parts of the solder, such as the leads and pads on the printed circuit board, so that the flat part of the soldering iron head (the larger part) and the larger heat contact the welding part capacity, one side of the soldering iron head. Or the edge parts contact the weldment with a small heat capacity to maintain uniform heating of the weldment.
Step 3: When the weldment is heated to a temperature where the solder can melt, the wire is placed at the solder joint, and the solder begins to melt and wet the solder joint.
Step 4: Remove the solder wire after melting a certain amount of solder.
Step 5: When the solder is completely wet, remove the soldering iron, and note that the direction of the removal iron should be roughly 45°.