Study Of Working Electrolyte Of High Voltage (160V) Low ESR Wet Tantalum Capacitors

Working electrolyte of high voltage (160V)-low ESR wet tantalum electrolytic capacitor (call the tantalum capacitor as follows) is studied in this paper.Currently, high voltage-low ESR is a developing trend of the tantalum capacitor. Along with the development of aerospace and the communications satellite business in our country, innovation of power supply technical, and controlling the pollution of the high frequency syntonic wave to electronic current has already become the important problem that the global electronic device deviser face. Now, the active filter circuit is widely adopted to repress the electric current distortion of high frequency syntonic wave. Once the active filter circuit is adopted, wet tantalum capacitor will face the rigorous test of high voltage and high frequency.The working electrolyte break-down voltage theory, conductance theory and the electrical double layer theory of cathode of tantalum were studied, and the influence of anion and organic compound on sparking voltage and ESR of working electrolyte were analyzed, synthesizing all the effect factors to improve the electrical performances of tantalum capacitor. The results of theories research show that the sparking voltage of working electrolyte is the most important factor that influences the tantalum capacitor rated voltage and reliability, furthermore, increasing working electrolyte conductance can effectively decrease capacitor's ESR.Therefore, the way to increase break-down voltage is to decrease electrolyte acidity and add some organic compound into it. We must make the break-down voltage to be satisfied at first, and then increase the electric conductivity of working electrolyte to decrease the ESR of tantalum capacitor, and improve its comprehensive electrical function.We also studied the ionic distributing and the function of electrolyte on the interface between Ta2O5 dielectric and electrolyte. Under the instruction of the theories, we developed the working electrolyte that used for 160 V/1μF, 160 V/47μF wet tantalum capacitor by using orthonormal experiment full factor design method. Use this newly developed working electrolyte to immerse and assemble two kinds of...