What is the function of PCB board ventilation holes

　　The ventilation holes on the PCB board mainly have the following important functions:

　　1、 Balanced air pressure

　　During the process of temperature changes on the PCB board, such as reflow soldering, wave soldering, or temperature changes in actual usage environments, the air inside the PCB board will undergo thermal expansion and contraction. If the PCB board is completely sealed, this change in air pressure may cause deformation, delamination, or other physical damage to the PCB board. The presence of breathable holes can maintain a balance between the air pressure inside the PCB board and the external air pressure, avoiding damage to the PCB board caused by stress due to pressure differences.

　　2、 Eliminate moisture and volatile substances

　　During the manufacturing process of PCB boards, such as cleaning and coating, there may be residual moisture or volatile substances inside the PCB board. If these moisture and volatile substances are not discharged in a timely manner, they may cause corrosion, short circuits, and other problems on the PCB board during subsequent use. Breathable holes can allow these moisture and volatile substances to be discharged from the PCB board at the appropriate time, improving the reliability and service life of the PCB board.

　　3、 Improve welding quality

　　During the welding process, good breathability helps to expel welding gases. For example, during the wave soldering process, the gas generated by the volatilization of the flux can be smoothly discharged through the ventilation holes, avoiding the formation of bubbles or virtual soldering defects on the PCB board.

　　4、 Improve heat dissipation efficiency

　　Although the ventilation holes themselves are not the main heat dissipation channels, they can to some extent promote the circulation of air inside the PCB board. In some special cases, such as when the heat distribution on the PCB board is uneven, ventilation holes can help transfer heat through air convection, thereby improving the overall heat dissipation effect of the PCB board.