The leakage current problem of ceramic capacitors is a common technical problem in electronic engineering. Before explaining the leakage current of ceramic capacitors in detail, it is first necessary to understand the mechanism of its generation. Leakage current usually occurs when the rated DC operating voltage is applied to the ceramic capacitor. Under the action of voltage, the initial charging current of the capacitor will gradually increase, gradually decrease as time goes by, and finally stabilize at a final value, which is called leakage current. Since the capacitor medium cannot be completely non-conductive, when a ceramic capacitor receives a DC voltage, a certain amount of current will always flow through it.
The leakage current of ceramic capacitors is usually very small, often expressed in microamperes, which is why the insulation performance of ceramic capacitors is often measured by insulation resistance parameters. When testing with a capacitor withstand voltage tester, the measurement of leakage current is based on the principle of applying rated voltage. If the leakage current does not exceed the specified standard value at the rated voltage, then the capacitor is a qualified product.

There are two main reasons for leakage of ceramic capacitors. The first is the degradation of surface insulation performance caused by surface contamination. In this case, the leakage current generated is usually not very large, generally only at the microampere level. In this case, a simple hot air treatment will usually restore the insulation value. Followed by internal cracks, including cracks caused by welding and cracks generated during the capacitor manufacturing process. This kind of crack may cause leakage current to continue to increase, and in severe cases, it may even cause local fires.
In order to avoid leakage of ceramic capacitors, it is crucial to choose capacitors produced by quality-assured manufacturers. High-quality ceramic capacitors have small leakage current, low losses and high capacity consistency, which helps reduce unnecessary risks and losses. Therefore, when choosing ceramic capacitors, it is key to pay attention to the quality of the product and the reputation of the manufacturer. Through precise selection and management, problems caused by leakage current of ceramic capacitors can be significantly reduced and the safety and efficiency of electronic equipment can be ensured.