1. If the pH value of the plating solution is low, the amount of hydrogen precipitation becomes larger, which is easy to cause pinholes in the plating layer;

2. If the plating solution contains ferric ions or the content of organic impurities is too high, pinholes will increase;

3. If the content of the humidifier is too low, it will naturally cause more pinholes;

4. When the anode area is insufficient, it will also cause pinholes and pitting.