Full solution to the formation of solder beads on PCB

During the process of PCB processing, there may be many small problems, including the plating delamination we mentioned earlier. Today, let's learn about another common problem - tin beads. At the same time, we will also bring you the reasons for the formation of PCB solder beads for your reference.

When the PCB board leaves the liquid solder, it is very easy to form solder beads. This is because when the PCB board and the tin wave are separated, they will be drawn into tin pillars. When the tin pillars are broken and fall back into the tin cylinder, solder will be splashed out and fall on the PCB board to form tin beads. Therefore, when designing tin wave generator and tin cylinder, attention should be paid to reducing the falling height of tin. A small landing height helps to reduce tin slag and splashing.

The second reason for the formation of tin beads is the release of volatile substances in PCB circuit boards and solder resist layers. If there is a crack in the metal layer of the through hole of the PCB circuit board, the volatilized gas from these substances after heating will escape from the crack and form tin beads on the component surface of the PCB circuit board.

The third reason for the formation of solder beads is related to flux. The flux may remain under the components or between the PCB board and the carrier (tray for selective soldering). If the flux is not sufficiently preheated and burned out before the PCB circuit board contacts the tin wave, tin splashing will occur and tin beads will be formed. Therefore, the preheating parameters recommended by the flux supplier should be strictly followed.

These are the three major reasons for the production of solder beads on PCB boards. Of course, there are many other small reasons that can also cause the production of solder beads. However, with the development of science and technology, technicians have begun to have rich experience in the production of solder beads. These experiences can also quickly help technicians find solutions. This may be the charm of science and knowledge.