Technology Overview


SBE has been in the business of advanced capacitor technology for over 50 years, first as part of Sprague Electric and more recently as an independent company. SBE’s vast experience in solving power electronic problems with capacitor solutions has expanded into many technology areas:

Power Ring Film Capacitor™ Technology – This innovative capacitor design, developed in 2005, changes the physical construction of film capacitors in ways that optimize desired characteristics. Supported by life testing and simulation tools partially funded by the US Department of Energy (DoE), this capacitor technology is available today in production quantities and at industry-leading prices versus traditional designs. More and more customers are relying on fielded and qualified SBE Power Ring Film Capacitors to reach the next generation level in Power Electronics.

Some of the benefits of this technology include:

  • Extremely low internal losses (ESR) – 0.15 – 0.4mOhms typical
  • Industry leading ESL characteristics – 2 – 12nH typical
  • Extreme current pulse survival
  • Significant volumetric capacitor density
  • Inverter topology design for optimized current rating and reduced coolant need
  • High temperature polypropylene film capacitor designs

105ºC Coolant DC Link Capacitor – A metallized polypropylene film capacitor technology (development partially funded by the US Department f Energy) capable of CONTINUOUS use with a 105ºC coolant for transportation applications. This same technology allows for the use of aggressive air cooling techniques and is scalable for voltages ranging from 450 – 2,100V. These products are in production and shipping into the field, in quantity. Extensive life testing was performed and validated as part of the program.

Patented Pulse Technology – A patented approach to enhance the capability of film capacitors for extreme current density. This innovation has been adopted by numerous customers with demanding pulse requirements, typically solving failures or design limitations vs. the use of conventional film capacitor technology.

SBE pulse technology produces 2 very desirable outcomes with a very minor cost increase vs. traditional technology (usually less than a 20% increase on the capacitor itself):

  • A significant increase in the current density capability of the capacitor, typically on the order of 30 – 50% prior to destructive failure points and with high volume manufacturing consistency.
  • A full containment of any damaged areas of over current events completely eliminating the common occurrence of “destructive unzipping” that occurs when traditional pulse current film capacitors sustain over current damage.

High Voltage – Corona-free Dry Film Capacitors – A pioneer in the design and application of high voltage film capacitors without the use of liquid impregnants for high voltage applications, SBE has performed extensive validation of these capacitors’ designs and uniquely performs corona-free operation verification on every manufacturing lot which is shipped – regardless of production volume. Simple UL validation and burn-in processes don’t ensure that long-term corona-free operation occurs. These widely-used practices only verify that a fatal condition has not yet occurred during the prescribed period of burn-in.

Wireless and Inductive Power Capacitors – With products in the field for over a decade in demanding applications, SBE is a leader in capacitor solutions to the inductive heating and charging markets. We have great experience in the destructive forces on a capacitor in these resonant high current applications. SBE is currently supplying capacitors and interconnect designs for the wireless charging market, inductive heating industry, and the demanding application of inductive real-time power of commercial products at low cost points.

System Integration – Having developed the highest-performing DC link and wireless charging capacitors in the industry, SBE is assisting customers with the optimized design of interconnect and cooling to get the maximum value out of its capacitors and additionally maximize switch performance and cooling efficiency. We offer standard designs as well as custom designs for optimized systems. Often the system design includes collaboration with our semiconductor, bus, and cooling partners.

Testing Capabilities – SBE has some of the most extensive test capabilities in the market for design validation of high power conversion systems, including:

  • Corona Inception Voltage (CIV),
  • ESL measurement to the nH level with resonance sensitivity,
  • Overshoot measurements of switches with different connections and DC links,
  • Temperature rise testing to verify hotspot temperature as a function of ESR, thermal resistance, and thermal boundary conditions. This is done using ripple current sourcing up to 500Arms – 20kHz with full cooling options flexibility, thermal imaging of hotspots and induced heating.
  • Thermal cycling, elevated temperatures burn in.

For many topics of interest to Power Electronics designers, please refer to our technical papers, presentations and application notes sections.

SBE is very active in trade conferences and industry trade shows. To see where you can talk with SBE application engineers and view our products and solutions, refer to SBE Conferences Calendar.