SCREENING METHOD FOR ELECTROLYTIC CAPACITORS

• Main Authors: MILLMAN WILLIAM A, MICHAEL I MILLER, MARK LEINONEN, MARC V BEAULIEU
• Format: Patent
• Language: English
• Published: 17.03.2014
• Subjects: BASIC ELECTRIC ELEMENTS; CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES ORLIGHT-SENSITIVE DEVICES, OF THE ELECTROLYTIC TYPE; ELECTRICITY

PROBLEM TO BE SOLVED: To provide a screening method for electrolytic capacitors.SOLUTION: A method of iteratively screening a sample of electrolytic capacitors having a predetermined rated voltage is provided. The method includes measuring a first leakage current of a first set of capacitors, calculating a first mean leakage current therefrom, and removing, from the first set, capacitors 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.