Reliability testing method for polymer electrolytic capacitors
KEMET introduced its KO-CAP Reliability Assessment method, the first of its kind for polymer electrolytic capacitors. The T540 and T541 Commercial-Off-the-Shelf (COTS) Series are the only polymer electrolytic capacitors available today with failure rate options defined by this innovative testing criteria
Developed as a result of over ten years of research, the Reliability Assessment method utilises accelerated voltage and temperature conditions applied to board-mounted samples to assess long-term device reliability. The failure rates available are B (0.1% per 1,000 hours), C (0.01% per 1,000 hours) and D (0.001% per 1,000 hours).
This Reliability Assessment method complements the successful T540 and T541 COTS Series KO-CAPs. These high performance capacitors are designed for decoupling and filtering applications that require very low equivalent series resistance (ESR). By utilising an organic conductive polymer as the cathode plate of the capacitor, this technology results in low ESR, high ripple current capability and improved capacitance retention at high frequency.
Such performance characteristics are suitable for various high reliability defence and aerospace applications such as radar, sonar, power supplies and guidance systems. KO-CAPs with the new Reliability Assessment method are available with rated voltages from 2.5 to 63VDC, capacitances up to 1,500 µF, and ESR as low as 5 mΩ – all in surface mount packaging.
Design engineers can now match the reliability requirements of their project to the appropriate failure rate. Traditional Weibull methods of assessing reliability are not suitable for polymer electrolytic capacitors and fall short of properly assessing lot-to-lot reliability. Prior to this release, this capability was only available through source control drawings, but is now easy to design in by adding the desired failure rate to the 13th character of the part number.