Degradation and ESR Failures in MnO2 Chip Tantalum CapacitorsEquivalent series resistance (ESR) of chip tantalum capacitors determines the rate of energy delivery and power dissipation thus affecting temperature and reliability of the parts. Employment of advanced capacitors with reduced ESR decreases power losses and improves efficiency in power systems. Stability of ESR is essential for correct operations of power units and might cause malfunctioning and failures when ESR becomes too high or too low. Several cases with ESR values in CWR29 capacitors exceeding the specified limit that were observed recently raised concerns regarding environmental factors affecting ESR and the adequacy of the existing screening and qualification testing. In this work, results of stress testing of various types of military and commercial capacitors obtained over years by GSFC test lab and NEPP projects that involved ESR measurements are described. Environmental stress tests include testing in humidity and vacuum chambers, temperature cycling, long-term storage at high temperatures, and various soldering simulation tests. Note that in many cases parts failed due to excessive leakage currents or reduced breakdown voltages. However, only ESR-related degradation and failures are discussed. Mechanisms of moisture effect are discussed and recommendations to improve screening and qualification system are suggested.
Teverovsky, Alexander A. (ASRC Federal Space and Defense Greenbelt, MD, United States)
April 17, 2017
April 11, 2017
Electronics And Electrical Engineering
Meeting: Annual CMSE Components for Military & Space Electronics Training & Exhibition 2017
Location: Los Angeles, CA
Country: United States
Start Date: April 11, 2017
End Date: April 13, 2017
Sponsors: Components Technology Inst., Inc.
Public Use Permitted.
Equivalent Series Resistance (ESR) Degradation Tantalum Capacitors