• Under the joint claim “Accelerating transformation for a sustainable future,” TDK shows highlight solutions for green and digital transformation from May 6 to 8, 2025,  in the NürnbergMesse exhibition center in Nuremberg, Germany
• At PCIM in booth 350 in hall 9, visitors can explore the latest passive component and sensor solutions for wind and solar power, ESS, hydrolyzer, heat pumps, EV charging, electric mobility (xEV), and AI 
• At SENSOR+TEST in booth 204 in hall 1, visitors can explore the latest sensor technologies to optimize the performance and reliability of industrial and automotive solutions

TDK Corporation (TSE:6762) showcases its latest passive component and sensor innovations at this year’s PCIM and SENSOR+TEST, taking place in parallel from May 6 to 8, 2025, in the NürnbergMesse exhibition center in Nuremberg, Germany. “Accelerating transformation for a sustainable future” is TDK’s joint claim for both shows, where visitors can explore TDK’s solutions for both green and digital transformation in the application areas of automotive, industrial, home appliances, and artificial intelligence. TDK's exhibit at PCIM in hall 9, booth 350, features passive components and sensor solutions for applications such as energy and power conversion, heat pumps, EV charging, mobility (xEV), and AI. Just around the corner, in hall 1, booth 204, visitors at SENSOR+TEST can delve into the whole spectrum of sensor technologies from different TDK group companies. 

Solution highlights at PCIM, hall 9, booth 350:

• Electric Mobility (xEV): 
  TDK is showcasing a busbar design with our modular xEVCap as a DC link capacitor as well as a bidirectional 22-kW onboard charger. Innovative power magnetics like transformers with integrated resonance choke minimize losses and save valuable space in onboard chargers. The aluminum nitride (AlN) multilayer substrates and 3D-printed AlN liquid coolers allow a 400-kW traction inverter to fit into a space about the size of two decks of playing cards.

• Energy & Power Conversion (Wind, Solar, ESS, Hydrolyzer, etc.): 
  TDK will display a modular inverter solution based on CeraLink used as flying capacitors, as well as a 250-kW inverter block for commercial and agricultural vehicles. The company will also introduce the next generation of its award-winning ModCap; the ModCap High Performance is capable of operating at elevated temperatures of +105 °C without derating. Visitors can explore a wind power stack weighing 60 kg equipped with 15 capacitors from the MKP DC HF series in the DC link. Just as small as a sugar cube is the gate drive transformer EP9, which has an operational isolation voltage of 500 V for driving IGBTs and MOSFETs on the high side of a half bridge. 

• EV Charging:
  TDK presents various reference designs like a bidirectional 22-kW onboard charger as well as a modular hybrid inverter for 10 + 15 kW. The company will also showcase several new DC link and safety EMI capacitors, as well as high voltage contactors like the HVC50 for currents up to 750 A at 1500 V for megawatt charging stations. 

• Sensor Solutions: 
  To reduce costs by significantly lowering the number of components in heat pumps, TDK showcases integrated pressure and temperature sensors. Taking a real e-motor, the company illustrates its comprehensive portfolio of sensor solutions to drive the motor to the max without pushing it over the edge.

Presentations

• Niklas Edkvist, TDK Europe: Panel discussion on “Powering AI: What Market and Technology Trends in Powertrain?” on May 6 at 11:20 AM on the Technology Stage in hall 4, stand 435 

• David Olalla, TDK Electronics: “Practical Use of xEVCap: The Modular and Standard DC-Link Capacitor for the Main Powertrain Inverter” on May 8 at 10:10 AM in room Mailand

Product highlights at Sensor+Test, Booth 204, Hall 1:

• Hall-effect Automotive Sensors: 
  Visitors can explore more about new stray-field robust mainstream 2D Hall-effect sensors HAL/R 35xy for automotive applications, like steering wheel angles, brake and accelerator pedals, valve positions, and chassis detection. These are available in single-die (HAL 3550) and dual-die (HAR 3550) versions, with analog and digital outputs. 

• Embedded motor control solutions: 
  TDK will also display the new cost-efficient HVC 5481G programmable gate driver SoC for automotive actuators, fans, and pumps. They can drive an external power bridge of 6 N-channel FETs with sensor-based and sensorless algorithms from BEMF commutation to single-shunt FOC. 

• Analog & digital MEMS microphones:
  TDK showcases audio capture, acoustic activity detection, and spoken keyword detection.

• WeWALK Smart Cane 2: 
  Experience the multi-award-winning cane, featuring TDK’s microphone sensors, ultrasonic sensors, and motion sensors, to enhance accessibility for individuals with visual impairments, all while maintaining an ergonomic design.

• Ultrasonic sensor modules: 
  TDK presents a solution that detects objects and measures distances in challenging environments, including full sunlight, translucent targets, and vibration in autonomous mobile robots (AMR) or autonomous guided vehicles (AGV).

• Pressure sensors: 
  At the booth, visitors can learn more about combined pressure and temperature sensors for thermal management, as well as pressure sensors for fuel tank leakage detection and industrial applications. 

• Temperature sensors: 
  On display are also surface temperature sensors for industrial as well as automotive applications, including an e-motor busbar sensor, an e-motor small case series, clip-on sensors for heat pumps, and a sensor for high voltages.

The Hongqi site in China has now also started operating its own photovoltaic system. More than 1,750 solar modules are installed on the roofs of several buildings, covering an area of 4,580 square meters. They generate 1,120 megawatt hours of electricity per year, which corresponds to 3.4 percent of the plant's annual electricity requirements. The site's CO_₂ emissions will be reduced by 715 tons per year.

In addition to the roofs of the office buildings, factory halls, and residential buildings, the roofs of the parking lots are also being used for solar modules. In addition, charging stations have been installed that employees and visitors can use to charge their vehicles. Site CEO Tomas Novak emphasizes the relevance of the project: “The adoption of green energy not only reduces our operational costs but also enhances environmental benefits, paving the way for a more sustainable and efficient future.”

The Deutschlandsberg, Heidenheim, Zhuhai FTZ, Johor Bahru, Kalyani, Kutina, Málaga, Nashik, Šumperk, Szombathely, and Xiamen locations already have their own systems. A further system is about to be commissioned in Batam, and expansions to existing systems are planned at various sites. Overall, the solar energy generated at and for TEG sites worldwide has risen continuously in recent years to around 24,700 megawatt hours in the T129 financial year. A further increase to around 44,000 megawatt hours is planned for the new T130 financial year.

TDK Corporation (TSE:6762) announces the HVC50, a high-voltage DC contactor designed for connecting or disconnecting lithium-ion batteries with up to 1500 V in traction applications, energy storage systems (ESS), and megawatt charging systems (MCS). With this component, TDK enables its customers to drive the green transformation towards an all-electric society and reduce carbon footprint.

In a single event, the HVC50 can disconnect DC voltages of up to 1500 V and DC currents of up to 1000 A in less than 30 ms. Continuously, it can carry up to 750 A. Weighing 1.7 kg and measuring 97.8 x 140 x 94.2 mm, this component is designed for the demanding requirements of industrial applications and commercial vehicles, combining reliability, safety, and easy integration.

The HVC50 features a ceramic arc chamber with a gas-filled design, ensuring rapid and safe current disconnection even under extreme conditions. Its integrated mirror contact, compliant with IEC 60947-4-1, enhances operational safety by providing precise switching feedback. Thanks to the bidirectional capability of the contactor, currents can flow both ways seamlessly, making it exceptionally versatile. A dual-coil design for operating voltages of 12 or 24 V ensures energy-efficient operation. The making power is 50 W, whereas the steady-state power is just 6 W, because after some 200 ms, one of the two coils can be switched off.

Certified to CE, UKCA, and UL standards, the HVC50 contactor aligns with global safety and performance benchmarks, supporting its use in various regions, including Europe, the US, and Asia. By addressing the growing demand for efficient and reliable power in ESS and MCS, the HVC50 is poised to accelerate the adoption of sustainable energy solutions and high-capacity charging infrastructures worldwide.
 

• A photo-spintronic conversion element capable of responding at ultra-high speeds of 20 picoseconds using light with 800 nm wavelengths, 10X faster than conventional semiconductor-based photo detectors 

• Concepted and developed by TDK, the magnetic device can detect both near-infrared and visible light

• Successfully demonstrated operation in collaboration with Nihon University in Japan, known for fundamental physics research 

• It can be applied to photoelectronic conversion technology, which is expected to improve data processing speed and reduce power consumption, both critical for further AI evolution 

TDK Corporation (TSE:6762) announces that it has developed the world’s first* “Spin Photo Detector,” a photo-spintronic conversion element combining optical, electronic, and magnetic elements that can respond at an ultra-high speed of 20 picoseconds (20 × 10⁻¹² s) using light with a wavelength of 800 nm [1] – more than 10X faster than conventional semiconductor-based photo detectors. This new device is expected to be a key driver for implementing photoelectric conversion technology that boosts data transmission and data processing speed, particularly in AI applications, while simultaneously reducing power consumption. 

Transferring mass amounts of data at higher speeds and with lower power consumption is an inevitable need as AI evolves. To process data and make calculations, data is currently transferred between CPU/GPU chips as well as from and to memory by electrical signals. Therefore, there is an increasing need for optical communication and optical interconnects, which offer high speeds that do not decrease with interconnect distance. Photoelectronic conversion technology is also gaining global interest as a very compact fusion of both optical and electronic elements. 

To address these challenges, TDK adapted its magnetic tunnel junction (MTJ) technology, which is currently used in billions of HDD heads, for photonics. One of the major advantages of this technology is that it does not require crystal growth using a single crystal substrate, and the device can be formed regardless of the substrate material. Comparatively, conventional semiconductor-based photo detectors have physical limitations at shorter wavelengths. Because the Spin Photo Detector has a completely different operating principle and uses an electron heating phenomenon, it can operate at ultra-high speeds even when the wavelength is shortened [1]. In addition, the operating wavelength range is wide, and it has been confirmed that it can operate from visible light to near-infrared light. TDK has successfully demonstrated the Spin Photo Detector with Nihon University in Japan, a research pioneer for the measurement of ultrafast phenomena of magnetic material.  

Additionally, with the ability to detect visible light at high speeds, the spin photo detector will be useful in applications projected for future growth, such as devices for AR/VR smart glasses ([2], [3]) and high-speed image sensors. While conventional semiconductor photo-sensing devices have weak cosmic-ray resistance, MTJ elements are also known for their strong cosmic-ray resistance and are expected to be used as light-detecting elements in aerospace applications. In the future, based on these results, TDK will improve the perfection of the high-speed light detection element to further pursue its usefulness. 

*Source: TDK, as of April 2025

TDK Corporation (TSE:6762) announces that its subsidiary Tronics Microsystems will exhibit at booth #2569 at the Offshore Technology Conference 2025 from May 5-8, 2025. The event will take place at NRG Park in Houston, Texas, and will feature a wide range of innovative solutions for the future of offshore energy.

Tronics will showcase its high-performance MEMS inertial sensors and spotlight a high-temperature MEMS accelerometer for inclination measurement in directional drilling applications. Leveraging a strong track record in serving demanding aerospace and railway markets, Tronics will demonstrate how its industry-unique closed-loop sensor’s architecture paves the way to a new generation of drilling guidance tools operating under high temperature, vibrations, and shock conditions.

Attendees can also look forward to a live demo of a miniature north-seeking MEMS gyroscope enabling precise azimuth measurement in downhole survey tools

• New 100 V product for automotive applications with 10 μF capacitance in 3225 case size (achieving large capacitance)
• Contributing to the reduction of component count and the miniaturization of sets
• Qualified based on AEC-Q200 

TDK Corporation (TSE: 6762) has expanded its CGA series for automotive multilayer ceramic capacitors (MLCCs) to 10 µF at 100 V in 3225 size (3.2 x 2.5 x 2.5 mm – L x W x H), with X7R characteristics (Class Ⅱ dielectric). This is the industry’s highest capacitance* for a 100-V rated product in 3225 size and this temperature characteristic. Mass production of the product series began in April 2025.

While power consumption has increased and high-current systems have become more widespread in recent years with the increasing sophistication of ECUs, there is also demand for lighter vehicles (with lighter wiring harnesses), and the use of 48 V battery systems is becoming increasingly widespread. With this, there has been an increasing demand for high-capacity 100-V products, such as smoothing and decoupling capacitors used in power lines. 

CGA series 100-V products achieve twice the capacity of conventional products of the same size thanks to optimized material selection and product design. This new product makes it possible to halve the number of MLCCs used and the mounting area, contributing to the reduction of component count and miniaturization of sets. TDK will further expand its lineup to meet the needs of customers. 

*Source: TDK, as of April 2025

The Zhuhai FTZ site has now also started operating its own photovoltaic system. More than 3,500 solar modules have been installed on the roofs of several buildings, covering an area of around 12,000 square meters. They generate 2,100 megawatt hours of electricity per year, which corresponds to 2 percent of the plant's annual electricity requirement. The site's CO₂ emissions will be reduced by 2,240 tons per year.

The photovoltaic system went into operation at the end of March after a construction period of around four months. Even the roofs of the parking lots are used to generate electricity. Project Manager Louis Lee emphasized the importance of the new facility and its contribution to sustainable development: “This project is an important milestone for our site in the area of renewable energies and supports our goal of a green future.”

The Deutschlandsberg, Heidenheim, Hongqi, Johor Bahru,Kalyani, Kutina, Málaga, Nashik, Sumperk, Szombathely, and Xiamen locations already have their own systems. A further system is about to be commissioned in Batam, and expansions to existing systems are planned at various sites. Overall, the solar energy generated at and for TEG sites worldwide has risen continuously in recent years to around 24,700 megawatt hours in the T129 financial year. A further increase to around 44,000 megawatt hours is planned for the new T130 financial year.

Figure 1:

The team at the Zhuhai FTZ site.

The Xiamen capacitors site in China has received the Excellence Award from the Japan Institute of Plant Maintenance (JIPM) for continuous improvements in manufacturing. The award recognizes measures implemented as part of Total Productive Maintenance (TPM) that lead to efficient production. The site had introduced TPM in 2019.

TPM aims to maximize equipment effectiveness and overall operational efficiency through systematic tools and structured processes. All employees should be actively engaged in continuous improvement initiatives, contributing to sustainable growth in all areas using the SQDCM method (Safety, Quality, Delivery, Cost, Morale).

More sales, more efficient production

Since the introduction of TPM in November 2019, the site has achieved significant improvements in various key figures. The factory's turnover has doubled and new product sales have grown fivefold. Overall Equipment Effectiveness (OEE) increased by 46 percent, while equipment failure rates have been reduced by 85 percent. Furthermore, the number of improvement projects has tripled and the number of suggestions from employees has increased nearly tenfold. Moreover, the skills and capabilities of employees have been enhanced, fostering a culture of continuous improvement and innovation.

In addition to further developing its own transformation, the Xiamen site is also collaborating actively with other TDK sites to promote TPM methods and concepts. The aim is to support sites in their transformation and to further strengthen the concept of TDK United.

“Receiving this award is a testament to hard work and dedication of every team member, as well as the support of the management," says site CEO Eric Liu. "Looking ahead, we are at a new starting point and need to further integrate system tools into the behavioral culture, continuing the transformation process towards operational excellence. This will enable our team to grow sustainably and create even greater value for our customers, for society and for the company.”

Figure 1:

At the TPM kick-off event in November 2019, together with Dr. Werner Lohwasser (TEG CEO and COO and ECBC COO).

TDK Corporation (TSE:6762) launches B58101A0851A000, the first in a new line of immersion temperature sensors (ITS), designed specifically for EV powertrain cooling applications. This highly responsive, fully sealed NTC thermistor is engineered to provide fast and precise temperature control, e.g., for oil-cooled systems. Oil cooling is anticipated to become the dominant temperature management method in the electric drivetrain of EVs. Leveraging TDK's expertise in developing tailored temperature sensor solutions, the ITS offers a flexible, customizable design adaptable to various installation positions, cooling fluids, and mounting configurations.

Combined with a lightweight design (<11 g), the temperature sensor has a response time of less than 4 s (τ63%) and maintains an accuracy of below ±1 K over the temperature range of -40 °C to +150 °C. This can enhance the effectiveness of thermal management. The sensor is highly resistant to ZF EcoFluid E gear oil for electric drive systems, has a customizable resistance-temperature (RT) curve, and is available in various mounting configurations.

This immersion temperature sensor exemplifies TDK's commitment to delivering precision-engineered, customizable thermal solutions for evolving e-mobility applications.
 

• Compatible with high currents of up to 1600 mA
• Ensures high impedance across a wide frequency range
• Suitable for high-temperature environments; supports a wide operation range of -55 °C to +155 °C

TDK Corporation (TSE: 6762) announces the expansion of the ADL3225VF series (3.2 x 2.5 x 2.3 mm; L x W x T) of wire-wound inductors for automotive power-over-coax (PoC). Mass production of these new components began in March 2025.

Advanced driver-assistance systems (ADAS) are designed to enhance vehicle safety by using automotive cameras and sensors that monitor the driving environment. These systems rely on multiple cameras, typically installed at the front, rear, and sides of the vehicle, to capture real-time imagery for safe and secure driving. In standard configurations, automotive cameras require two separate lines for power and signal transmission: a power line connected to the vehicle’s battery and a signal line connected to the electronic control unit (ECU). However, with PoC technology, a single coaxial cable can simultaneously carry both power and data, simplifying and reducing cabling. This can reduce the vehicle’s weight, which in turn can improve fuel efficiency and lower carbon emissions.

TDK’s new ADL3225VF series implements a rated current of 1.6 A, which is equivalent to that of the ADL4532VK series (released on February 13, 2025), while achieving a reduction in the mounting area of approximately 45%. The PoC system requires a filter incorporating multiple inductors to separate power from the data signal before processing effectively. In comparison with the conventional products, ADL3225VM-2R2M, the new ADL3225VF series increases the rated current by approximately 20% by using proprietary materials and structural design innovations. At the same time, the ADL3225VF series delivers high impedance across a wide frequency range from tens of megahertz (MHz) to hundreds of megahertz. This reduces the number of inductors used, saving space. Additionally, the inductor ensures high reliability with an upper operation temperature limit of +155 °C. 

Looking ahead, TDK is committed to developing inductors for automotive PoC applications by pursuing optimized design by refining multilayer, wire-winding, and thin-film technologies to address market needs. TDK will expand its lineup of products to improve the quality of PoC transmission signals. 

The Nashik site in India is sourcing additional solar power from a further photovoltaic field. Covering an area of 113,000 square meters, the external plant generates 13,400 megawatt hours per year, which corresponds to 35 percent of the plant's electricity needs. Together with the electricity that the site has been purchasing for four years from another photovoltaic field and the electricity from its own photovoltaic system on the roof of the capacitor production, the plant can now cover 75 percent of its energy needs with green electricity.

The new photovoltaic field is located approximately 550 kilometers east of Nashik in the country's interior. TDK India has entered into a partnership with an external power generator that has constructed the plant and has invested 26 percent of the equity capital.

The solar power generated is used exclusively by the Nashik site. This enables the plant to reduce its CO2 emissions by almost 11,000 tons per year and to cut electricity costs.

The management of TDK India expressed its satisfaction at reaching another milestone in the utilization of alternative energies: “TDK Nashik has achieved yet another significant milestone in green energy transition by installing the second offsite solar plant”, says Prabal Ray, Chairman and Managing Director TDK India. “We feel proud to lead by example in the transition to a clean energy future. We will continue to explore more such opportunities and are fully committed to create a greener world.”

Around 3,000 panels on an area of almost 11,000 square meters: the photovoltaic system on the roof of the capacitor production facility in Nashik went into operation in 2019 and generates around 1,300 megawatt hours of solar power a year.

TDK Corporation (TSE: 6762) is excited to launch the TDK SensEI edgeRX, which represents a significant leap forward in industrial maintenance, bringing cutting-edge innovation to the forefront of machine health monitoring.

edgeRX is an advanced machine health monitoring platform that leverages the power of AI on edge sensor devices. By integrating advanced AI algorithms, edge computing, and powerful sensor devices, edgeRX provides real-time machine health monitoring, predictive maintenance insights, and actionable alerts directly on machines. 

edgeRX is a comprehensive, out-of-the-box solution which eliminates the need for extensive setup or specialized integration, allowing reliability engineers, maintenance technicians, and plant managers to quickly deploy and benefit from advanced machine monitoring capabilities. By proactively identifying potential issues before they escalate. edgeRX maximizes uptime, reduces maintenance costs, and enhances overall operational efficiency, making it an indispensable tool in modern manufacturing environments.

Supported by TDK’s extensive history in sensors and components, TDK is well-positioned to build and enhance the edgeRX platform, ensuring best-in-class performance and reliability. With decades of innovation and expertise, TDK Corporation has been a global leader in electronic components, sensors, batteries, and materials technology. TDK's rich legacy of pioneering advancements in these fields provides a strong foundation for the development of cutting-edge solutions like edgeRX.

The integration of snubber capacitors or part of the DC-link capacitance into the power module for inverters is a trend that aims towards improving the overall inverter efficiency and performance on the one hand and lowering the system costs on the other. However, due to the harsh conditions inside the power module, only ceramic capacitors can be considered. CeraLink, a high-voltage ceramic capacitor from TDK, which is specially designed for power electronic applications, can offer significant advantages over standard multilayer ceramic capacitors (MLCCs), especially when it comes to fast-switching power module applications using silicon carbide (SiC) or gallium nitride (GaN).

The power inverter is a crucial component in electric vehicles (xEVs), converting the DC power from the car battery into AC power to drive the motor. High efficiency and reliability are essential to maximize the vehicle's range, performance, and lifetime. More and more xEVs operate at high voltages (typically around 800 to 900 V) to improve efficiency and reduce charging times. The inverter must be capable of handling these high voltages safely and reliably. By using advanced power semiconductors like silicon carbide (SiC) or gallium nitride (GaN) transistors, lower losses and higher efficiency can be achieved. Nevertheless, effective cooling solutions are necessary to manage the heat generated during operation due to losses. Innovative designs, such as double-sided cooling structures, help to optimize thermal performance and reduce the overall size and weight of the inverter, which is important for improving vehicle range and handling. Besides efficiency and performance, also solution cost is important since the development and manufacturing of high-performance power inverters is expensive. One of the main cost drivers in the power module is the SiC dies. Consequently, any possibility of operating these components more efficiently or reducing the number of required dies can bring significant cost savings.

Figure 1a: Schematic of a standard inverter topology with the HV supply (e.g. battery), the inverter module, and a conventional DC-link capacitor solution.

 

 

Figure 1b: Schematic of a standard inverter topology with the HV supply (e.g. battery), the inverter module, and a distributed DC-link capacitor solution where a part of the capacitance is moved close to the power module.
 

Figure 1c: Schematic of a standard inverter topology with the HV supply (e.g. battery), the inverter module, and an integrated snubber within the power module.
 

Depending on the inverter topology, modern power inverters for xEV typically require a DC-link capacitance of several hundred microfarads which is usually realized using e.g. metalized polypropylene film capacitors (Figure 1(a)). However, such film capacitors are bulky and the desired placement close to the switches is often not possible. Hence, there is a significant parasitic inductance between the DC-link capacitor and the SiC MOSFETs. In combination with steep switching slopes (high di/dt), this can lead to severe voltage overshoots, even with a well-designed busbar. These overshoots not only put the switches at risk but also increase the overall system EMC, potentially requiring larger and more expensive filters.

Hybrid systems, as shown in Figure 1(b) and (c), utilize the possibility to split the DC-Link capacitance by moving a smaller capacitance portion from the bulk DC-link as close as possible to (or even inside) the power module. This small capacitance portion is usually realized by compact low-inductive capacitors, e.g. ceramic capacitors. 

As these components are physically close to the switching elements, they can help to suppress voltage overshoots which otherwise potentially damage the switches. Commonly referred to as snubbers or decoupling capacitors, they store excessive energy from the parasitic inductance when the transistor is switched off. The same applies to the turn-on when the parasitic capacitances of the transistor must be instantly charged. If a ceramic capacitor is placed next to the switching device in parallel with the bulk DC-link capacitor, it can provide this current. Otherwise, this current must be drawn from the bulk DC-link capacitor with the higher parasitic inductance since it is further away from the switching transistor.

In such hybrid systems, the parasitic inductances (e.g. busbar and the DC-link) in combination with the snubber capacitance can lead to unwanted resonances which is usually referred to as the anti-resonance effect. This effect can lead to high reactive currents, far beyond the actual snubber current, leading to unexpected heating of the snubber capacitor and a drop in efficiency. This problem gets more severe if the anti-resonance frequency is close to the switching frequency or any relevant harmonics. With a not-optimized design, the anti-resonance frequency can be easily in the range of 200 to 400 kHz, which may already coincide with the harmonics of typical switching frequencies, leading to severe ringing. To mitigate this effect, the anti-resonance needs to be shifted towards higher frequencies. This can be achieved by minimizing the busbar inductance (e.g. by keeping the busbar as short as possible) and reducing the snubber capacitance to the lowest acceptable level. Furthermore, damping elements may be required, preferably with a frequency-dependency (e.g. by utilizing the skin effect). For more details, we refer to [1].

Figure 2: Influence of loop inductance on voltage overshoots at the semiconductor. The larger the inductance loop induced by the distance of the capacitor to the switches, the larger the voltage overshoots and vice versa. With a temperature rating of +150 °C, CeraLink can be placed very close to the semiconductors, therefore minimizing the inductance loop.

The next logical step is the integration of the snubber capacitor directly into the power module as shown in Figure 1(c). In this case, the snubbers can be placed as close to the switching elements as possible, which minimizes the overall loop inductance significantly, as indicated in Figure 2. Therefore, they work very efficiently to filter any voltage spikes and since the induced voltage overshoot is proportional to the parasitic inductance, less capacitance might be needed in the end.

But besides numerous advantages, the integration of capacitors into the power module imposes also several challenges. Only multilayer ceramic capacitors (MLCCs) can meet the requirements for energy density, current capability, temperature rating, and compactness. However, based on the employed ceramic material, different classes of MLCCs are available which all have their pros and cons. In the following, we consider three different materials, namely the well-known Class-I and Class-II dielectrics, but also an anti-ferroelectric dielectric which is used in TDK’s CeraLink and is specifically designed for tomorrow’s power electronic applications.

Pitfall DC bias effect, current capability, and temperature rating

The capacitance of Class-II MLCCs (e.g. X7R temperature class) decreases with the applied DC voltage—known as the DC-bias effect and shown in Figure 3 (a). The exemplary MLCC with Class-II dielectric (X7R), which has a voltage rating of 630 V and a nominal capacitance of 1 µF, provides only a fraction of this value at an operating voltage of 400 V, i.e. the capacitance drops by almost 80% of its nominal value due to the DC-bias effect. Furthermore, the capacitance also decreases with temperature as shown in Figure 3(b). Albeit this effect is usually less dominant compared to the DC-bias effect, particularly at elevated DC-bias voltages. Nevertheless, when both DC-bias and temperature effects are considered, the 1 µF turns into only approximately 0.2 µF at the operating point. This fact is crucial for many designs as the capacitance in the application then differs significantly from the expected value.

Figure 3: Capacitance characteristics as a function of (a) DC-bias voltage and (b) temperature for MLCCs with Class-I (C0G) and Class-II (X7R and X7T) dielectric in comparison with CeraLink.

Another drawback of MLCCs with Class-II dielectric is their limited current capability together with their tendency to show thermal runaway when several capacitors are combined in parallel, i.e. the hottest capacitor in the capacitor array tends to get even hotter such that the system becomes thermally and/or electrically unstable.

Finally, MLCCs with Class-II dielectric are usually limited to +125 °C max. device temperature, which might be on the edge for certain power module applications, since the SiC-MOSFET junction temperature can go up to +175 °C easily. When it then comes to lifetime, it makes a huge difference if the capacitor is operated already close to its upper-temperature specification (e.g. +125 °C) as compared to a capacitor that is rated for +150 °C but operated only at +125 °C. As a rule of thumb, the service life doubles with every 10 K temperature drop. Furthermore, challenging processing conditions during module assembly (e.g. high temperatures during reflow soldering) can be prohibitive for some standard capacitors.

On the other hand, the capacitance of MLCCs with Class-I dielectric (e.g. C0G temperature class) does not significantly depend on DC bias or temperature. Furthermore, they can handle high ambient temperatures as well as high operating currents easily. However, their capacitance density is typically low, requiring that several parts are required to achieve significant capacitance. This takes up a significant amount of PCB area and can lead to space issues, as well as increasing the overall loop inductance. Such a solution counteracts the original idea of having a low-inductive circuit.

Why CeraLink is different

Unlike MLCCs with Class-I or Class-II dielectric, CeraLink capacitors are based on lead lanthanum zirconium titanate (PLZT) ceramics offering an increase in capacitance with DC-bias voltage as shown in Figure 3(a). Furthermore, the capacitance increases with temperature up to a certain maximum and then decreases (refer to Figure 4). This effectively eliminates the risk of thermal runaway.

Figure 4: Capacitance characteristics of CeraLink over temperature and different DC-bias voltages. This characteristic prevents thermal runaway, which can occur in MLCCs with class II dielectrics.

Figure 5: ESR characteristics of CeraLink over frequency. This allows CeraLink to handle higher ripple currents at higher temperatures.

Figure 6: ESR characteristics of CeraLink over temperature and different DC-bias voltages. CeraLink works even more efficiently at high temperatures.

In addition, CeraLink performs very efficiently at elevated temperatures without the need for additional cooling. This is, firstly, achieved by the ESR decreasing with both frequency and temperature (see Figures 5 and 6), allowing it to deliver significantly higher currents in hot environment applications such as power modules. Secondly, CeraLink’s maximum temperature specification of +150 °C allows it to be placed very close to the semiconductors, helping to reduce the effects of parasitic inductance (see Figure 2). This can eliminate the need for additional thermal management, thereby lowering system costs, and reducing both the size and weight of the system. All these features render CeraLink very suitable for fast-switching power electronic applications using wide-bandgap technology.

System cost advantage

For easier comparison, we concentrate in this paragraph on common, standard MLCC case sizes like EIA 2220 with soft termination and AEC-Q200 (automotive) qualification. Furthermore, we consider only non-stacked MLCCs, respectively MLCCs without lead frames. Usually for automotive power module inverter applications a larger capacitance in the range of several hundred nanofarads to some microfarads is required. CeraLink can fulfill this request with the LP (Low Profile) and FA (Flex-Assembly) series.
 

To illustrate the total cost of ownership advantage of CeraLink over MLCCs with Class-II dielectric, consider a snubber application requiring some 50 nF at 800 V. A comparative analysis between CeraLink B58043E9563M052 (56 nF/900 V) and two to four MLCCs (both 1000 V) from various manufacturers demonstrates significant differences (Table 1). Due to the DC-bias effect, these MLCCs achieve only 12.6 nF, respectively 25.9 nF at an operating voltage of 800 V, necessitating three to four parallel units, whereas a single CeraLink 2220 component suffices.

Although the per-1000-unit price for CeraLink as offered by large online distributors is about twice as high as for most MLCCs, the snubber solution with CeraLink is more cost-effective for this application at this operating point. This cost advantage becomes even greater when PCB area and assembly costs are added. The bottom line is that CeraLink can save up to 60% of the cost based on the given example. Note also that the cost savings can be even higher if the benefits of having a less overall circuit inductance which allows for faster and harder switching are considered (e.g. cooling concept, less EMC, and cheaper filters).

Conclusion

Unlike conventional MLCCs with Class-II dielectric, the capacitance of CeraLink increases with DC-bias voltage and temperature up to their operating point. This characteristic makes them highly versatile for various power electronic applications. They excel at suppressing voltage peaks, and, thanks to their low equivalent series inductance (ESL), they are perfectly suited for working hand in hand with fast-switching wide-bandgap semiconductors. Their ability to handle high ripple currents due to low equivalent series resistance (ESR) at high frequencies and temperatures further highlights their adaptability. Additionally, their ability to operate at high temperatures allows them to be placed very close to high-power switches, effectively damping voltage spikes during rapid switching events (Table 2).
 

In addition to their functional benefits, CeraLink capacitors can enhance cost-effectiveness by minimizing or even eliminating the need for thermal management or filtering. This reduction in system costs also contributes to a decrease in the size and weight of the final product. CeraLink is available in different voltage and capacitance ranges which fit different customer requirements.

Next steps in module integration

The next evolutional step in terms of power module design would be the use of multilayer ceramic substrate materials such as aluminum nitride (AlN). This new substrate material from TDK enables many architectural benefits and boosts the power module to the next level.

The efficiency of power modules is typically highest when operating close to their limits, resulting in higher operating temperatures. Precise and accurate temperature control is essential to operate at these limits and to prevent the semiconductors in the power modules from overheating. To address the temperature accuracy challenge, TDK developed lead-free and RoHS-compatible SMD NTC thermistors that describe the corresponding R/T characteristic curves of existing non fully RoHS-compatible technologies available on the market, enabling a seamless substitution.

References

[1] Neudecker, M. and Chatterjee, P., Mitigating DC Link Anti-Resonance for WBG-Based Designs; Bodo’s Power Systems; 10/2024, pp. 42-46

Contact

• The international SBTi has verified TDK greenhouse gas reduction targets as science-based
• Targets are set for both direct emissions and emissions from the entire value chain
• Long-term targets support the ultimate goal of achieving net zero emissions by 2050

TDK Corporation (TSE: 6762) announces that its greenhouse gas (GHG) emissions net-zero targets are now verified by the Science Based Targets initiative (SBTi). SBTi recognizes that TDK's long-term targets align with the objective of limiting the global temperature rise to 1.5 °C above pre-industrial levels, consistent with the Paris Agreement (date of verification by SBTi: February 3, 2025).

The following TDK net-zero (long-term) targets have been approved:

• Target 1: Reducing absolute scope 1 and 2 GHG emissions by 90% within fiscal 2050 from a fiscal 2021 base year
• Target 2: Reducing absolute scope 3 GHG emissions by 90% within fiscal 2050 from a fiscal 2021 base year

The approval of TDK’s long-term net-zero targets follows the prior approval of its near-term targets in June 2024. As part of the company’s efforts to achieve a net-zero target, TDK has introduced renewable energy sources into its operations.

Since July 2023, all manufacturing sites in Japan have operated with 100% electricity from renewable energy sources. TDK achieved the target of increasing the use of electricity from renewable energy sources to 50% across the entire group by fiscal 2025 in fiscal 2023, two years ahead of schedule. TDK will continue to aim to convert 100% electricity from renewable energy sources for the entire group by fiscal 2050.

Based on the SBT certification, TDK plans to further reduce GHG emissions and encourage its suppliers to set GHG emission reduction targets, thereby reducing GHG emissions throughout its supply chain and contributing to a sustainable future.