Wilhelm Westermann in Unna/Westphalia in 1948 created and established WIMA Germany. They make High Technology, Specialized Passive Components. These are Plastic film capacitors, Paper capacitors and Supercapacitors.
The capacitors that need special mention are RFI and Snubber Capacitors. They also make Intermediate Circuit Capacitors or DC-Link capacitors, that can replace Electrolytics in SMPS or DC/AC Drives.
These capacitors are especially designed to attenuate voltage spikes on GTO (Gate-Turn-Off) Thyristors and IGBT (Insulated Gate Bipolar Transistor). They are manufactured in dry-type technology with a dielectric of metalized polypropylene film and encapsulated in a cylindrical plastic case sealed with self-extinguishing polyurethane resin.
These caps have Very low self-inductance and High pulse reliability (snubber). High rms current carrying capability (HF filter). Value Ratings upto 100uF and 1KV available.
The Double Layer Capacitors developed by WIMA are storage capacitors with highest capacitance values in the Farad range. They are among others suited to serve as batteries, can deliver considerably higher currents for a short time, however, and are maintenance free.
Despite the limitations of its maximum operating voltage of 2.5 V, several cells can be built up to enormous capacitance of the desired voltage by means of series or parallel connection (cascade). When cascading SuperCaps, the voltage of single cells must not exceed 2.5 V (decomposition of the electrolyte!)