what are the main reasons for the capacity attenuation, capacity decrease and loss increase of aluminum electrolytic capacitor?-足球看盘软件

aluminum electrolytic capacitors are widely used in consumer electronics, industrial control, communication products, computers and peripheral products, instruments and meters, automobile industry and other products. they are one of the irreplaceable main members of the capacitor family. the basic structure of aluminum electrolytic capacitor is that there is an aluminum shell outside. the sealed aluminum shell contains electronic aluminum foil, electrolytic paper, electrolyte, etc., and leads out two positive and negative electrodes. due to the complexity of aluminum electrolytic capacitor structure and manufacturing process, some problems will inevitably occur in the process of production, storage and use, such as capacity attenuation, loss increase and so on.

 

it is generally believed that the capacity attenuation of aluminum electrolytic capacitors is mainly due to the following three reasons:

 

1. excessive lubrication between the aluminum needle and the riveting foil, resulting in excessive contact resistance between the riveting needle and the aluminum foil, such as excessive lubrication and the riveting hole;

 

2. the capacity of anode foil or cathode foil cannot be fully extracted due to insufficient electrolyte, resulting in capacity attenuation, such as high electrolyte viscosity, poor permeability, incomplete immersion or too long drying time, poor sealing performance, electrolyte volatilization or

 

loss and other reasons;

 

3. poor control of product aging process parameters leads to thickening of anode or cathode foil oxide film and capacity attenuation, such as too high aging voltage or temperature, bearing reverse voltage due to misoperation in the aging process, etc.

 

the capacity of aluminum electrolytic capacitor decreased significantly in the later stage of use, mainly due to the large loss of electrolyte, the increase of viscosity of electrolytic solution and the increase of resistivity due to the increase of viscosity, which increased the equivalent series resistance of working electrolyte and significantly increased the loss of capacitor. the ability of electrolyte with increased viscosity to repair the oxide film surface decreases, which reduces the effective area of the electrode plate of the capacitor, resulting in a sharp decline in the capacity of the aluminum electrolytic capacitor, which is also a sign that the service life of the capacitor is near the end. moreover, the low-temperature performance of working electrolyte of some systems is poor, and the high viscosity leads to the surge of equivalent series resistance, which increases the loss and reduces the capacitance, which is easy to cause early failure under severe cold operation.