"How Materials and Environmental Effects Influence Capacitor Performance"

he PSMA Capacitor Committee and IEEE PELS held the fifth annual pre-APEC Capacitor Workshop "How Materials and Environmental Effects Influence Capacitor Performance" on Saturday March 19, 2022 at the George R. Brown Convention Center in Houston, TX. The workshop participants and presenters from around the world came together for the program which included 14 presentations and 4 demonstration tables where experts showed many applications and measurement methods. The 2022 Workshop was successful and notable in that we were finally able to meet our customers, colleagues and friends in-person again after holding virtual workshops in 2020 and 2021.

After breakfast in the Demonstration Area, the Workshop began with a keynote presentation "The Next Decade Capacitor Requirements" from Tomas Zednicek, President of EPCI - European Passive Components Institute, who discussed the future of capacitor technologies with a special focus on materials, reliability and sustainability. This was followed by a presentation by William Greenbank from Centre for Industrial Electronics (CIE), University of Southern Denmark, who provided insight into the latest academic research on capacitor materials for the green transition. Frank Puhane, Würth Elektronik, rounded out the first session with a summary of the differences for Class 1/Class 2 MLCCs with a special look at the terminations.

The second session focused on Electrolyte and Tantalum Capacitors. Stephan Menzel from CapXon showed aluminum e-cap solutions for applications with demanding environmental conditions including increased operating temperatures or vibrations where designing a power supply requires a bulk capacitor to ensure good performance. Daniel West from Kyocera-AVX presented an overview of different options and trends to select the right bulk capacitor with a focus on reliability. When the application requires the highest possible volume capacitance, the solution favors tantalum capacitors, and it was a great honor to have Philip Lessner, CTO of KEMET, to guide us through the world of tantalum capacitors. In the final presentation of the morning, Nihal Kularatna from the University of Waikato explained how Supercapacitors could be used for renewable energy and DC micro grid applications. The session concluded with a panel discussion including many of the morning's presenters.

After this wealth of information, it was time for a joint lunch with attendees from the concurrent Power Magnetics @ High Frequency Workshop in the demonstration area. Workshop participants were able to visit the demonstrations from both workshops, discuss the morning program with the presenters and other workshop attendees, and to network with friends and colleagues.

Building on the technologies, trends and selection procedures that had been reviewed in the morning sessions, the first afternoon session focused on the influences of environmental conditions on capacitor applications. This session included not only how temperature and humidity affect capacitors performance, but also the impact of other influences such as the AC voltage and the packaging.  Frank Puhane showed how the different capacitor technologies behave under temperature influences and Philip Lessner explained how capacitors behave in a high humidity environment. Since the characteristics of MLCCs will change not only through DC bias, but also through AC bias, the session concluded with presentations by two well-known experts on capacitors presenting on this topic. John Bultitude from KEMET gave us insight into the MLCC rating for AC Applications and Douglas C. Hopkins from North Carolina State University then went on to discuss packaging for higher AC voltages and future trends in high power converters.

The final technical presentation session focused on the measurement and characterization of capacitors. Measurement and characterization should always be considered together since how the capacitors are measured is crucial for making comparisons. Therefore, Jon Izkue Rodriguez from Würth Elektronik showed how to interpret data sheets and how different components are measured. This topic was further demonstrated in a related demonstration station. High power converters, as described by Douglas C. Hopkins, use DC link capacitors which should have a very low parasitic inductance (ESL). Measuring the ESL can be a challenge and Ronald Alexander from Zurich Instruments presented on how to accomplish this. The final presentation, provided by Marcus Sonst from Rohde & Schwarz, was on how to determine the aging in an AC/DC flyback application using an oscilloscope.

The information-packed day concluded with a joint Capacitor and Magnetics Rap Session moderated by Alexander Gerfer, CTO of Würth Elektronik. The panel members Douglas Hopkins, Philip Lessner and Tomas Zedineck representing Capacitors and Mike Arasim, Fair Rite Products Corporation; Alex Hanson,University of Texas at Austin; and Chema Molina, Frenetic representing Magnetics had very interesting and exciting discussions on the topic of selection, sustainability and applications of passive components.

Many thanks to Pierre Lohrber who has led the organizing effort for all of the PSMA/PELS Capacitor Workshops starting with the first workshop in 2018 and has now moved on to new opportunities. Also, a big thank you to all presenters: Tomas Zednieck, William Greenback, Frank Puhane, Stephan Menzel, Daniel West, Phil Lessner, Nihal Kularatna, John Baltitude, Douglas Hopkins, Jon Izkue Rodriguez, Ronald Alexander and Marcus Sonst.

We hope to see you and many more at our next Capacitor Workshop being planned for March 18, 2023 in conjunction with APEC 2023 in Orlando, Florida. More details regarding the agenda for the 2023 Capacitor Workshop as well as registration information for the workshop will become available on the PSMA website (http://www.psma.com/technical-forums/capacitor/workshop) in the coming months.

Provided by members of the Capacitor Workshop Organizing Committee:
Frank Puhane, Wurth Electronics
Fred Weber, Future Technology Worldwide

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