1. The shape of the soldering iron head can adapt to the surface requirements of the weldment and the assembly density of the product.

2. The temperature of the tip of the soldering iron tip needs to be compatible with the melting point of the solder, which generally needs to be 30-80 degree higher than the melting point of the solder (excluding the temperature dropped when the soldering iron tip touches the soldering point).

3. The heat capacity of the electric soldering iron must be appropriate, and the temperature recovery time of the soldering iron tip must be compatible with the requirements of the surface of the weldment.

1. When welding integrated circuits, transistors and other components that are vulnerable to heat, consider using a 20W internal heating or 25W external heating electric soldering iron.

2. When welding thicker wires and coaxial cables, consider using a 50W internal heating type or a 45-75W external heating type electric soldering iron.

3. When soldering larger components, such as metal chassis grounding pads, you should choose an electric soldering iron above 100W.