Analizirajte vzroke za kratek stik keramičnega kondenzatorja
Capacitors are subject to failure or damage if improper use or other external factors occur in the process of use. Especially for ceramic capacitors, ceramic capacitor leakage problem also often troubled many engineers.
First of all, the surface insulation drop caused by surface dirt, this kind of leakage current is not very large, usually micro-amp level, hot air blowing insulation value will rise. Secondly, internal cracks, there are cracks caused by welding and cracks caused by poor manufacturing of porcelain chip capacitors. The leakage current caused by these cracks will rise continuously and cause local fire in serious cases. Many companies’ technicians are unable to analyze whether it is a capacitor problem or not. Because once moving the soldering iron or heating up, all will return to normal, many engineers are often wrongly analyzed as solder paste problem, many people encountered and did not analyze correctly before accurate analysis, cut open the sample to microscope observation, indeed the capacitor has a problem. For ceramic capacitor leakage from the reliability point of view, is a typical low stress failure, monolithic capacitors, relays, polyester capacitors have these problems. If the power supply is not clean leading to it, it will leak after a certain time of working under this DC voltage abnormality, and it will grow more and more serious with time.
Ceramic capacitor is a kind of capacitor made of ceramic material as dielectric, coated with a metal film on the surface of ceramic, and then sintered at high temperature as electrode. It is usually used in highly stable oscillation circuit as circuit, bypass capacitor and pad whole capacitor. In the process of making ceramic capacitors we all encounter the short circuit, what causes the short circuit?
A short circuit is when the power supply is directly connected by wires into a closed circuit without passing through the load. Short-circuit current is the current when not connected, equivalent to the current when a wire is directly connected to the positive and negative phases of the battery. The causes of short circuit of porcelain chip capacitor are as follows.
1)The quality is not good
2) High voltage breakdown
3) Unstable voltage
4) Insufficient reserve margin
5)The ambient temperature exceeds the range of use
6)The ceramic capacitor is damaged during the transportation.