"Environmental considerations play a key role in our work"
IEC TC 40 is the technical committee which prepares standards for capacitors as well as other important components used in electronic equipment. Capacitors are used to store energy on printed circuit boards as well as to filter signals and smooth out voltage fluctuations in power supplies. Their demand is expected to explode as miniature electronics grow, notably for Internet of Things (IoT) applications and as new industries such as electric vehicles (EVs) require their use. The Chair of IEC TC 40, Markus Schwerdtfeger, explains key market trends and what challenges are on the horizon.
What important new standards are you working on?
We are developing IEC TR 63650, a technical report which deals with electrochemical capacitors for use in electrical energy storage and which is close to publication. With this document, TC 40 opens a new chapter by working in cooperation with other technical committees representing the supply chain of products for use in electrical storage systems (EES) and charging stations for EVs. These emerging applications for electrochemical capacitors create challenges to align manifold requirements, starting from nano-scale raw materials for electrodes (under the scope of IEC TC 113) via the manufacturers of capacitor cells (under the scope of TC 40) and storage modules to the manufacturers of EES (under the scope of IEC TC 120) and of the EV charging infrastructure (under the scope of IEC TC 69). There is no specific TC for the capacitor storage modules themselves and we still need to decide which group should take these requirements on board.
What are the demands from industry?
Demand for standardization along this supply chain covers elements of terms and definitions, metrology, how to define and measure the relevant parameters, operating conditions as well as related requirements for the cells and storage modules. We also have requirements for the design of storage modules, monitoring their state-of-health, methods for lifetime prediction and most probably various additional aspects. This technical report is the starting point of activities, to be continued via the existing liaisons between TC 40 and the other TCs related to these products and applications.
Another important standard is IEC 60068-2-88, which was published in 2025. It addresses the testing of the resistance of components and assemblies to liquid cleaning methods. Due to increasing miniaturization, printed circuit board assemblies are becoming much more densely packed. This makes the thorough cleaning of the boards after soldering extremely challenging, yet this is absolutely essential to ensure their long-term reliability. We must guarantee that our passive components can withstand these modern, sometimes highly aggressive liquid cleaning methods without any damage to the component casings or the fine terminations.
This is exactly where the importance of looking at the bigger picture becomes evident. This standard intertwines seamlessly with the work of IEC TC 91, which develops standards for electronics assembly technology. TC 91 defines the requirements for the assembly and soldering processes, which in turn necessitate these specific cleaning steps. If capacitors and resistors standardized by TC 40 cannot survive these assembly-level cleaning processes, the entire board fails. Component development and assembly technology must therefore totally work hand in hand. To paraphrase Andrea Bonetti from IEC TC 95 in e-tech: if experts don't interoperate and our standards don't mesh, the finished electronic systems won't either.
How important are environmental considerations in the work you do? How does that reflect in your standards?
Environmental considerations play an absolute key role in our work. As recently highlighted in e-tech, rising global temperatures have a direct impact on electronics. For TC 40, climate change specifically means that passive components like capacitors must withstand more extreme ambient temperatures and operate reliably under thermal stress over longer periods. Our standards reflect this through significantly more stringent climatic testing procedures.
A second, equally important aspect is sustainability and the circular economy. The longevity of our components is crucial for extending the lifespan of end devices, thus reducing the flood of e-waste. This commitment crosses committee boundaries: in my role as Chair of the German national mirror committee for TC 91, I am actively working on new, environmentally vital topics such as component "rework" and "long-term storage" to further support the repairability and extended use of electronics. In addition, environmental regulations for avoiding hazardous substances, such as RoHS and REACH, are now deeply embedded in our material specifications and testing standards. We ensure that tomorrow's capacitors are not only high-performing but also environmentally friendly throughout their entire lifecycle – meaning they can be sustainably produced, safely and efficiently transported, and properly disposed of or recycled at the end of their life.
How do you see the market for capacitors evolving in coming years? Any new areas of demand?
The market for capacitors is currently evolving at an incredibly dynamic pace. We are talking about a global volume of trillions of passive components produced annually. This growth is primarily driven by major technological megatrends that are creating entirely new areas of demand.
Take the electrification of transport, for example. Compared to traditional internal combustion engines, EVs require a massive number of high-performance and direct current (DC)-link capacitors – such as for traction inverters and battery management. Moreover, these must operate absolutely reliably under extremely harsh conditions.
Another important area is the energy transition. The expansion of renewable energies like solar and wind power, as well as the roll-out of modern smart grids, require huge quantities of capacitors for power conversion and grid stabilization.
And last but not least, we are seeing enormous demand driven by 5G, 6G and the IoT. The increasing interconnection of billions of devices, sensors and smart city infrastructures is rapidly driving up the need for highly miniaturized, high-frequency capacitors for signal processing and filtering.
What are the main challenges you face moving forward?
The biggest strategic challenge we face in TC 40 is clearly the generational shift. As Andrea Bonetti recently said so aptly, we urgently need to attract younger experts to standardization work. This is absolutely essential for our future viability.
We actively need professionals with fresh knowledge in modern materials science – for instance, for new dielectrics – as well as in high-frequency engineering and power electronics. The pace of development in the industry is enormous; standardization must remain agile so as not to become a bottleneck for new technologies.
The challenge lies in finding experts who not only bring deep technical understanding of components but are also willing to learn the methodology of international, consensus-based standardization work. We are looking for people who can bridge the gap between hardware innovations and automated manufacturing processes.
How does miniaturization and automation impact the capacitor market – and hence TC 40 standards?
Miniaturization is a primary driver in our industry. Components are becoming microscopically small, yet they must deliver the same or even higher performance. For TC 40, this means enormous challenges, especially regarding thermal management and reliability in the tightest of spaces. We have to continuously adapt our testing procedures for these tiny surface-mount devices (SMD).
And this is where automation comes into play: when components become this small, manual handling is completely out of the question. Machine placement (pick-and-place), soldering and automated optical inspection (AOI) on the production lines must run absolutely flawlessly and at top speeds. That is why, in our dedicated working groups – like WG 36 – we are developing extremely precise standards for the automated handling and packaging of components. Only through these standards can we ensure that highly automated production lines worldwide operate smoothly and without costly interruptions, while maintaining our uncompromisingly high quality standards.
What is the overlap or not with IEC TC 33? How do you work together?
That is a very good question. There is a clear dividing line between us, but the points of intersection are growing steadily. TC 33 deals with power capacitors. Above all, these must be extremely robust components designed for high voltages in the power grid, in power transmission or in large industrial plants. We, in TC 40, on the other hand, focus on capacitors for electronic equipment – that means low voltage, microelectronics and the printed circuit board level.
The overlaps are occurring right now precisely where grid technology and control electronics are merging. A perfect example of this is charging infrastructure for EVs or large inverter stations for renewable energies. In such systems, you will find the robust high-voltage components from TC 33 sitting right next to our highly precise control electronics from TC 40.
We work closely together at these interfaces and exchange information. As I mentioned earlier, the same fundamental principle applies here across different committees: interoperability on a human level is the absolute prerequisite for technical safety and reliability.
Markus Schwerdtfeger is an engineering graduate from the Wilhelm Buechner University of Applied Sciences in Germany and an MBA holder from Warsaw University in Poland. He embarked on his career as a Communication Electronics Engineer working for PKI and Lucent in Germany. He then went on to work for several companies as a Quality Engineer, including Siemens VDO. He also made an important stint as a Research and Development Engineer at the Fraunhofer Institute where, among other things, he developed electronic circuits. From 2017 onwards, he has been the Manager of Quality Assurance at the German branch of Murata Electronics. He has been involved in standardization since 2019. He actively contributes to the working groups of IEC TC 91, serves as Convener of TC 91/WG 1 in addition to leading IEC TC 40, and is deeply involved in the related mirror committees of the German National Committee (DKE).