At present, the package replacement of electronic components is getting faster and faster, the components on the circuit board are getting fewer and fewer, the density is getting denser, the pins are getting thinner, and the circuit board is getting smaller and smaller. Moreover, a large number of surface mount components, flip chips and other components are used on the circuit board, which without exception shows that the electronics industry has developed towards miniaturization and miniaturization, and the difficulty of manual soldering has also increased accordingly. Caution will damage components, or cause poor welding, so the staff must have a certain understanding of welding principles, welding processes, welding methods, evaluation of welding quality, and electronic foundation.
The electric soldering iron is the most commonly used tool in welding. Its function is to convert electrical energy into heat energy to heat the soldering point. A large part of the success of soldering depends on how well it is manipulated. Generally speaking, the greater the power of the electric soldering iron, the greater the heat, and the higher the temperature of the soldering iron tip. For example, we use a 20W internal heating type (30-40W external heating type) soldering iron for hardware transformation. If the power is too high, it is easy to burn out the components. Generally, diodes and triodes will be damaged if the junction temperature exceeds 200°C. Generally, it is most appropriate to complete the welding of a component within 1.5-4s.
