Although the automation equipment has been advanced enough to replace most of the manual work, due to the particularity of some components and components that can not be recognized by the machine, manual soldering is still needed to complete the work. Artistic and accurate soldering process is an important index to test the welder. Today, let's take a look at the steps of manual soldering of printed circuit boards and precautions.
The specific operation steps of soldering printed circuit board can be divided into five steps, which is called five step engineering methods. Strict operation is required to obtain good soldering quality.
Prepare for soldering: prepare solder wire and soldering iron. The head of the soldering iron should be kept clean, that is, it can be stained with solder (commonly known as eating tin).
Heating weldment: contact the soldering iron with the welding point. Firstly, keep the soldering iron to heat all parts of the weldment, such as the lead wire and pad on the printed board. Secondly, pay attention to make the flat part of the soldering head contact with the weldment with larger heat capacity, and the side or edge part of the soldering iron head contact with the weldment with smaller heat capacity, so as to keep the weldment evenly heated.
Melting solder: when the weldment is heated to a temperature that can melt the solder, then put the welding wire at the solder joint, the solder will start to melt and wet the solder joint.
Remove the soldering tin: remove the solder wire after a certain amount of soldering tin is melted.
Remove the soldering iron: when the solder joint is completely wetted, remove the soldering iron. The direction of removing the soldering iron should be about 45 degrees.
Soldering according to the above steps is one of the keys to obtain good solder joint. In actual production, one of the easiest to violate the operation steps is that the soldering iron head does not contact with the weldment first, but with the solder wire first, and the melted solder drops on the welded part which has not yet been preheated, so it is easy to produce solder joint virtual soldering. Therefore, the soldering iron head must contact with the weldment. Preheating the weldment is an important means to prevent false soldering.