Why do capacitors fail when stored for a long time
Writer：Capacitor manufactur Source：Internet Time：2020-10-09 05:52:00
【DESCRIPTION】：1. In the process of long-term storage, the rated voltage should be applied regularly to keep the activity of electrolyte. Otherwise, the electrolyte in the capacitor will lose its activity and be aged. Once the electrolyte loses its activity and aging, the electrolytic capacitor will be invalid.
2. Aluminum electrolytic capacitor is very sensitive to chlorine and bromine. If halogen containing flux, cleaning agent, fixing agent and fumigant are used, halide may invade into the capacitor through sealing rubber plug, which is easy to cause anode corrosion of capacitor and accelerate capacitor failure after power on. Therefore, it is necessary to strictly control the halogen components of sensitive preparations used in the production process.
3. After aluminum electrolysis is stored at high temperature for a long time, chemical reaction will occur between anodic oxide film and electrolyte, resulting in voltage drop and leakage current increase. When the capacitor voltage is close to the rated voltage, it may lead to over-voltage failure or large leakage current, resulting in overheating failure.
4. Aluminum electrolytic capacitor with electrolyte can not be sealed 100% due to the cost problem, so it will gradually dry up. The time is determined by the application environment and its own quality. The service life of qualified products (which meet the national standard or other mandatory quality standards under strict test conditions) is more than ten years in the rated range. When the electrical conditions are not bad, the temperature is the most important factor affecting the life of electrolytic capacitor, too high or too low will greatly shorten the service life of electrolytic capacitor. If the temperature is too high, over-voltage, reverse polarity will burst or even burst, and electrical breakdown will lead to short circuit or open circuit. Electrolytic capacitors are widely used in different fields of power electronics, mainly for smoothing, storing energy or filtering after AC voltage rectification, and also for non precision timing delay. In the MTBF prediction of switching power supply, the model analysis results show that electrolytic capacitor is the main factor affecting the life of switching power supply, so it is very important to understand and influence the factors of capacitor life. The life of electrolytic capacitor depends on its internal temperature. Therefore, the design and application conditions of electrolytic capacitor will affect the life of electrolytic capacitor. From the design point of view, the design method, material and processing technology of electrolytic capacitor determine its life and stability. For the users, the service voltage, ripple current, switching frequency, installation mode and heat dissipation mode all affect the life of electrolytic capacitor.
1. In the process of long-term storage, the rated voltage should be applied regularly to keep the activity of electrolyte. Otherwise, the electrolyte in the capacitor will lose its activity and be aged. Once the electrolyte loses its activity and aging, the electrolytic capacitor will be invalid.
2. Aluminum electrolytic capacitor is very sensitive to chlorine and bromine. If halogen containing flux, cleaning agent, fixing agent and fumigant are used, halide may invade into the capacitor through sealing rubber plug, which is easy to cause anode corrosion of capacitor and accelerate capacitor failure after power on. Therefore, it is necessary to strictly control the halogen components of sensitive preparations used in the production process.
3. After aluminum electrolysis is stored at high temperature for a long time, chemical reaction will occur between anodic oxide film and electrolyte, resulting in voltage drop and leakage current increase. When the capacitor voltage is close to the rated voltage, it may lead to over-voltage failure or large leakage current, resulting in overheating failure.
4. Aluminum electrolytic capacitor with electrolyte can not be sealed 100% due to the cost problem, so it will gradually dry up. The time is determined by the application environment and its own quality. The service life of qualified products (which meet the national standard or other mandatory quality standards under strict test conditions) is more than ten years in the rated range. When the electrical conditions are not bad, the temperature is the most important factor affecting the life of electrolytic capacitor, too high or too low will greatly shorten the service life of electrolytic capacitor. If the temperature is too high, over-voltage, reverse polarity will burst or even burst, and electrical breakdown will lead to short circuit or open circuit. Electrolytic capacitors are widely used in different fields of power electronics, mainly for smoothing, storing energy or filtering after AC voltage rectification, and also for non precision timing delay. In the MTBF prediction of switching power supply, the model analysis results show that electrolytic capacitor is the main factor affecting the life of switching power supply, so it is very important to understand and influence the factors of capacitor life. The life of electrolytic capacitor depends on its internal temperature. Therefore, the design and application conditions of electrolytic capacitor will affect the life of electrolytic capacitor. From the design point of view, the design method, material and processing technology of electrolytic capacitor determine its life and stability. For the users, the service voltage, ripple current, switching frequency, installation mode and heat dissipation mode all affect the life of electrolytic capacitor.
