Technical Technical Notes Notes Typical failure modes and factors of aluminum electrolytic capacitors Failure mode Failure mechanism (internal phenomenon) Production factor Application factor Over voltage applied Vent operates Increase in internal pressure Increase internal in temperature Excessive ripple current Capacitance reduction tan δ increase Reverse voltage applied Reduced anode foil capacitance Severe Reduced cathode foil capacitance charging-discharging Defect of oxide film Deterioration of oxide film Leakage current increase AC voltage applied Used for a high Insufficient temperature electrolyte Electrolyte evaporation Used for long period Metal particles of time In capacitor Short circuit Insulation breaddown of film or electrolytic paper Burr(s) on foil Stress applied to leads leads Leads improperly connect Leads improperly connected Mechanical stress Use of Halogenated solvent Open Corrosion Use of adhesive Infiltration of CL- Use of coating material Direct Contact and Support: Jianghai Europe GmbH - +49 (0) 21 51 - 65 20 88 - 0 - [email protected] - www.jianghai-europe.com