Films for capacitors

Louise Smyth

SABIC is introducing two new gauges of Ultem UTF120 polyetherimide (PEI) dielectric film for high-temperature, professional-grade capacitor applications. These new additions of 7µm and 10µm thicknesses to SABIC’s portfolio of Ultem UTF120 film respond to customers’ requirements for film that can meet the voltage requirements of different capacitors and open the door for new design options. 

The UTF120 film technology offers important advantages for capacitor applications, such as high dielectric constant and insulation resistance and low dielectric loss. The two new grades address the need for higher-voltage applications that require thicker film with greater storage capacity. These new film grades are part of an expanding portfolio that already features a 5µm Ultem UTF120 film product, which was launched last year. Currently SABIC is the only materials supplier offering extruded PEI film at these thicknesses.

“Today’s power electronics applications demand higher performance and greater reliability than ever before,” said Stephanie Gathman, director, Emerging Applications, SABIC. “SABIC is actively investing in new high-temperature film technologies that offer distinct advantages over previous options, including better thermal and electrical stability and longer service life.”

With a temperature range of -40°C to 150°C, Ultem UTF120 film exceeds the temperature performance of commodity capacitor materials such as polypropylene (PP) and polyethylene terephthalate (PET) film. As such, the new film may support demanding applications such as DC-DC converters and electric compressors for electric vehicles. Because the new film can handle higher temperatures, it can reduce or potentially eliminate the need to actively cool converter capacitors by way of a secondary source. For instance, the film can minimise the need for cooling loops used to reduce temperatures for PP and PET film capacitors, which have traditionally taken up precious under-bonnet space and can constrain design flexibility.