Three common reasons for PCB pads to fall off

During the use of PCBA boards, pads often fall off, especially when the PCBA boards are repaired. When using a soldering iron, it is very easy for the pads to fall off. How should PCB factories deal with this? This article analyzes the reasons for pads to fall off.

1. Board quality problems

Due to the poor adhesion between the copper foil and epoxy resin of the copper clad board, even if the copper foil of the circuit board with a large area of copper foil is slightly heated or under mechanical external force, it is very easy to separate from the epoxy resin, resulting in pads falling off or copper foil falling off.

2. Influence of storage conditions of circuit boards

Affected by weather or stored in a humid place for a long time, the PCB board absorbs moisture and contains too much water. In order to achieve the ideal welding effect, the heat taken away by the volatilization of water should be compensated during the patch welding. The temperature and time of welding should be extended. Such welding conditions are likely to cause the copper foil and epoxy resin of the circuit board to delaminate. Therefore, PCBA processing plants should pay attention to the humidity of the environment when storing PCB boards.

3. Soldering problems with electric soldering irons

Generally, the adhesion of PCB boards can meet the needs of ordinary soldering, and pads will not fall off. However, electronic products are generally likely to be repaired, and repairs are generally repaired by soldering with electric soldering irons. Since the local high temperature of the electric soldering iron often reaches 300-400℃, the local temperature of the pad is too high instantly, and the resin under the soldering copper foil falls off due to the high temperature, resulting in pads falling off. When the electric soldering iron is disassembled, it is easy to be accompanied by the physical force of the electric soldering iron head on the pad, which is also the reason for the pad to fall off.