Soldering experience with electric soldering iron
The electric soldering iron is the most commonly used tool in electronic welding. Its function is to convert electrical energy into heat energy to heat and weld the soldering point. A large part of its success depends on how well it is controlled. Therefore, from a certain point of view, the electric soldering iron The use of it depends on a sense of technique.
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. Generally, a 20W internal heating electric soldering iron is sufficient for welding of transistors and integrated circuit electronic components. If the power is too high, it is easy to burn out the components, because the junction temperature of diodes and triodes will burn out if the temperature exceeds 200°C. However, in the production of amplifiers mainly for scaffolding welding, the power of the electric soldering iron should be higher, and the power of the electric soldering iron can be selected from 35W-45W, or even higher.
It is worth noting that when the circuit is soldered, the time should not be too long or too short. If the time is too long, it will be easily damaged, and if the time is too short, the solder will not be able to fully melt, resulting in uneven solder joints and false soldering. For the most appropriate time must be completed within 1.5s ~ 4s.
Solder is a fusible metal, and the most commonly used is generally solder wire. The role of solder is to connect the component pins with the connection points of the printed circuit board, and the choice of solder has a great influence on the soldering quality. The most commonly used ones are rosin solder wires, but the subdivisions are also very particular. Among them, the silver solder wires that are not mixed with water are of course the top grade.
It is also worth mentioning the solder absorber, which is very practical for novices. It is always easy to get solder everywhere when using a soldering iron for the first time. The solder absorber can help you remove excess solder on the circuit board. In addition, the tin absorber is very effective when removing multi-pin integrated circuit devices. It can suck all the solder joints, but it is completely unnecessary for those who can skillfully use the soldering iron. It can completely replace its function with a soldering iron. The components can be easily removed by melting off the solder joints.
Before soldering, pre-soldering treatment should be performed on the component pins or the soldering parts of the circuit board. Remove the oxide layer on the soldering part - a knife can be made from a broken saw blade to scrape off the oxide layer on the surface of the metal lead to expose the metal luster of the lead. The printed circuit board can be polished with fine gauze paper, and then coated with a layer of rosin alcohol solution. Component tinning - tinning on scraped leads. After dipping the lead wire in the rosin alcohol solution, press the tip of the hot soldering iron with tin on the lead wire and turn the lead wire. The leads can be evenly plated with a very thin layer of tin. Before the wire is welded, the insulation sheath should be peeled off, and then the above two treatments can be performed before formal welding. In the case of multi-strand wires, they should be twisted together after polishing, and then tinned.
After the pre-welding treatment is done, the welding can be officially carried out:
(1) Hold the electric soldering iron in the right hand. Use needle-nose pliers or tweezers with your left hand to hold components or wires. Before soldering, the electric soldering iron should be fully preheated. Tin should be eaten on the blade surface of the soldering iron head, that is, a certain amount of solder should be brought on.
(2) Place the blade of the soldering iron tip against the solder joint. The electric soldering iron is at an angle of about 60° to the horizontal plane. To facilitate the flow of molten tin from the tip of the soldering iron to the solder joint. The time the soldering iron tip stays at the solder joint is controlled within 2 to 3 seconds.
(3) Lift the tip of the soldering iron. The left hand still holds the component. The left hand can only be released after the tin at the solder joint is cooled and solidified.
(4) Rotate the lead wire with tweezers to confirm that it is not loose, and then use the pliers to cut off the excess lead wire.
