TDK Electronics · TDK Europe

ModCap Standard Series

Modular Capacitor Concept

 Intro Pic

ModCap is a modular, versatile power capacitor concept for use in DC link applications. Combined with the latest generation of power modules, it enables compact converters for traction, renewable energy, and industrial applications to be brought to market quickly. Two product lines are available: ModCap MF for silicon IGBT modules and ModCap HF for silicon carbide MOSFET (SiC) modules. 

With ModCap HF, TDK adds a series that is particularly suitable for DC link applications in SiC-based converters. In combination with such very fast switching power modules, the components enable compact converters where a compact, robust design and highest power density are required. 

This high frequency capability is made possible by the flat capacitor windings connected in parallel as well as the eight terminal contacts and a new type of internal busbar. Therefore, the components can be placed very close to the SiC power modules and thus absorb the high-frequency harmonics excellently up to the frequency range of several hundred kilohertz. Together with the extremely low stray inductance of 8 nH, this prevents the voltage at the power modules from overshooting too much when the current is switched off. As a result, snubber capacitors are generally not required. This, in turn, reduces the footprint and cost of new-generation inverter designs, especially those using SiC technology. 

For both product families, biaxially oriented polypropylene (BOPP) is used as the dielectric, allowing a constant hotspot temperature of +90 °C until a new generation of dielectrics which TDK is currently developing enables hotspot temperatures of up to +125 °C. Simulation software is available to calculate the thermal behavior of the capacitors based on parameters such as frequency spectrum, maximum current, and customer-specific installation conditions. 

ModCap standard series


  • Modular concept for parallelization especially with IGBTs (ModCap MF) or SiC MOSFETs (ModCap HF) 
  • Extremely low ESL of 14 nH (ModCap MF) or even 8 nH (ModCap HF) 
  • Temperature up to +90 °C hot spot 
  • Lifetime up to 200.000 hours 
  • Simulation software available 


  • Cost optimization 
  • Reduced time to market and lead time 
  • Compact and high power density converters e.g., light traction or renewable energy  
  • Low voltage overshoot, therefore, no snubber capacitors needed  

Construction and Standards

  • Filled with polyurethane resin (dry technology) 
  • Plastic case (open) 
  • Flat windings 
  • Use of biocircular films
  • 8 terminals connection with a new generation of internal bus bar (ModCap HF) 
  • EC 61071, IEC 61881-1, EN 45545-2 HL3 R23 (fire and smoke), UL recognized  

Series comparison

ModCap MF
ModCap HF
Capacitance (µF)
ModCap MF
ModCap HF
Voltage (V DC)
ModCap MF
ModCap HF
ESL (nH)


Thermal simulation

Thermal model available for specific simulation according to spectrum and boundary conditions defined by the customer.

 Simulations Thermal Map

Electromagnetic simulation

Electromagnetic model available for specific simulation according to spectrum and boundary conditions defined by the customer.

 Simulations Electromagnetic

Higher sustainability through biocircular films

 Bild ModCap

TDK introduced a bio-circular polypropylene (PP) film for all its ModCap series. The ISCC-certified raw material is obtained from second-generation renewable raw materials (bio-circular) which come exclusively from waste and residues: from the production of vegetable oil, from the paper and pulp industry, or used cooking oil, for example. Thus, fundamental ethical issues should be avoided, such as conflicts with food cultivation which could increase food prices. Bio-circular PP raw material can be processed in the very same way as conventional ones. It is chemically identical, and in terms of performance, it has the very same electrical and physical properties.

Learn more:

Innovative Biocircular FilmISCC PLUS Certification


 Solar Grid

Get Data Sheets

PDF Type Application Style Number of phases Rated capacitance (µF)
B25645 DC link MKK DC-R NA 350 - 3900
B25647 DC link MKK DC-R NA 640 - 1850

In order to download up to 20 files together as zip, please mark them with the check box. To start the download, please click the Download button at the end of the list.

ModCap solves design problems

Why are snubber capacitors generally not required?

ModCap has been designed to minimize the stray inductance. ModCap HF achieves values around 8 nH for the whole series. Thanks to its design, the capacitors can be fitted very near to the SiC power modules, thus producing very short lead lengths. This stops any substantial voltage overshoot at the semiconductor modules when the current is shut off. As a result, no snubber capacitors are needed.

Why does ModCap have higher energy and power density than other solutions?

ModCap HF is based on the previous design of ModCap MF although with a slightly different internal construction and 8 terminals to enhance the performance at HF and the power density. The unique metallization of the films maximizes self-healing capability while withstanding high current densities thanks to its reduced film width, thus reducing losses. The capacitor dimensions were designed for current and future SiC power modules to optimize the DC link unit's footprint in terms of dimensions and power, almost equal dimension to small construction of ModCap MF.

What is the maximum hot spot temperature of this series?

Up to 90 °C of hot-spot temperature can be achieved during operation as in the case of ModCap MF thanks to the use of high crystallinity BOPP and our fine-tuned automated process parameters. New versions of ModCap HF to include high-temperature film is actually under development. 

As with ModCap MF TDK offers FEA simulations for ModCap HF for precise heat distribution in the capacitor, tailored to your specific electrical and mechanical conditions. TDK can simulate ModCap HF in customer setup, taking into account the electrical conditions and all other aspects that may have an influence, such as external electromagnetic interference, the cooling system, the mechanical assembly, and what is more importantly, the performance at HF together new generation of SiC semiconductors. 

Is ModCap compliant with fire and smoke regulations?

As ModCap, all materials used in rail vehicles for passenger transport must meet the EN45545-2 standard to achieve the highest level of safety possible in the event of a fire. Railway vehicles are classified in accordance with the fire hazard level associated with their design and operation. 

The three hazard levels are: HL1, HL2, and HL3 with HL1 being the lowest requirement and HL3 being the highest. ModCap MF series meets the high requirements of the new European fire protection standard EN 45545-2, reaching safety levels up to HL3 in the requirement set applicable to power capacitors (R22, R23, and/or R24). 

Therefore, ModCap HF can even be installed in bunks and bed wagons that cross long tunnels and railway vehicles operating on underground tracks. 

ModCap HF, as well as ModCap MF, are recognized as UL approval. 

Why ModCap is able to handle harmonics up to several hundred Kilohertz?

The basis for the use with high harmonics is the internal new generation bus bar included with ModCap HF. Thanks to its internal bus bar ModCap HF can handle the HF harmonics achieving a homogenous internal current distribution avoiding resonance effects.

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