| High voltage-low ESR working electrolyte used in 160V/1μF wet tantalum electrolyte capacitor is emphatically studied in the paper. Researching high voltage-low ESR wet tantalum capacitor is a developing trend. With growth in national spaceflight and communication satellite the new research is developing. It's an important problem for global electronic device devisers to control high harmonic distortion pollution on electronic current. There are many kinds of ways to control high harmonic distortion, but the same way is to adopt active filter circuit. If active filter circuit is adopted, wet tantalum capacitor will face test of high voltage and high frequency. Though four capacitors which used by series-parallel connection can satisfy of high voltage-low ESR requirements, communication satellite system must descent. So this is a stringent subject to research single core high voltage-low ESR wet tantalum capacitor. This paper researches working electrolyte break-down voltage theory ,conductance theory and electrical double layer theory of cathode surface, analyzes anion and organic compound of working electrolyte effect on break-down voltage and ESR, researches ionic conductance and working electrolyte effect on Ta2O5 dielectric film. Working electrolyte is selected by orthonormal experiment and assembled 160V/1μF capacitors which make all experiments, including 2000 hours 160V,85℃ and 125℃ high temperature reliability experiments to examine all kinds of capacitor electrical performances. On the basis of these theories, working electrolyte break-down voltage chiefly affects on wet tantalum capacitor rated voltage and reliability, increasing working electrolyte conductance can effectively decrease capacitor ESR. Therefore, the way to increase break-down voltage is to decrease electrolyte acidity and add organic compound. Tantalum capacitors experimental results show that all electrical parameters of capacitors assembled by researching working electrolyte can reach contract requirements. |
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