Screening method for electrolytic capacitors

• Main Authors: Beaulieu, Marc V, Miller, Michael I, Leinonen, Mark W, Millman, William A
• Format: Patent
• Language: English
• Published: 17.03.2020
• Subjects: BASIC ELECTRIC ELEMENTS; CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES ORLIGHT-SENSITIVE DEVICES, OF THE ELECTROLYTIC TYPE; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASURING; MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES; PHYSICS; SEMICONDUCTOR DEVICES; TESTING

A method of iteratively screening a sample of electrolytic capacitors having a predetermined rated voltage is provided. The method can include measuring a first leakage current of a first set of capacitors, calculating a first mean leakage current therefrom, and removing capacitors from the first set having a first leakage current equal to or above a first predetermined value, thereby forming a second set of capacitors. The second set can be subjected to a burn in heat treatment where a test voltage can be applied, then a second leakage current of the second set of capacitors can be measured and a second mean leakage current can be calculated. Capacitors having a second leakage current equal to or above a second predetermined value can be removed from the second set, forming a third set of capacitors. Because of such iterative screening, the capacitors in the third set have low failure rates.