(1) When soldering integrated circuits, transistors, and their heat sensitive components, consider using a 20W internal heating or 25W external heating soldering iron.

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

(3) When welding larger components, such as metal chassis grounding pads, a soldering iron with a power of over 100W should be used.

(4) The shape of the soldering iron tip should adapt to the requirements of the workpiece surface and the assembly density of the product.