If the capacitor is used improperly or by other external factors, it will be faulty or damaged. And what causes the ceramic capacitor to leak? The ceramic capacitor should be highly insulated under normal conditions, and the insulation value is as high as 1.0E+9 ohms. A variety of factors can cause the insulation of the ceramic capacitor to drop and cause leakage. There are two reasons for the summary:
The first is the surface insulation caused by surface contamination. This kind of leakage current is not very large, generally it is micro-ampere level, and the insulation value of hot air blowing will rise. Secondly, internal cracks, cracks caused by welding and poor fabricated ceramic capacitors. Leakage currents caused by such cracks will continue to rise, causing local explosions and fires in severe cases.
Secondly, the leakage of ceramic capacitors is a typical low-stress failure from the perspective of reliability. Multi-layer ceramic capacitors, relays, and polyester capacitors all have these problems. If the power supply is not clean, such as DC voltage abnormality, even if the rated voltage of the capacitor is 50V, 25V will leak, but this capacitance between 1~10V is the most serious, it works under such abnormal DC voltage. After a certain period of time, there will be leakage, and it will grow more and more and become more and more serious over time.
Analysis of the cause of leakage of ceramic capacitors is here. If you want to avoid such a situation, then you can choose good quality ceramic capacitors, such as YTF brand ceramic capacitors, good quality and good price, the thicker the better, the leakage current is small. The loss is small and the consistency of the capacity is very precise.