Carl Benz's first "automobile" from 1886 still largely managed without electrics - the high-voltage ignition system represented almost the entire electrification. Today's vehicles, on the other hand, resemble "rolling control cabinets", which place ever greater demands on the insulating materials as the electrification of the drive system increases.
The so-called low voltage (48 VAC or 70 VDC) usually only requires functional insulation - the touch voltage is sufficiently low that people are not endangered. However, even with 48 V (4 times the usual battery voltage in a vehicle with a combustion engine), no significant drive power can be achieved - the cable cross-sections required for the flowing currents are simply too large.
This is why significantly higher voltage levels are used today in hybrid vehicles and even more so in fully electric vehicles. This prevents large quantities of copper from making the vehicle unnecessarily heavy. However, this does mean that the vehicle is within the Low Voltage Directive (up to 1000 VAC and 1500 VDC). This places special requirements on insulation materials as well as clearance and creepage distances.
Specifications such as operating voltage, withstand impulse voltage, operating altitude, degree of soiling, thermal class, sensitivity to creepage distances and other properties not only result in requirements for the clearances and creepage distances, but also for the insulation material itself (see article Material suitability with regard to IEC 60664).
Kapton® HN and Kapton® FN (improved version with cti value 1) are ideal insulation films for ensuring sufficient, permanent and reliable isolation in the IT network or from the earthed power supply network in modern high-voltage concepts in electric vehicles. They help to reduce sizes and allow very compact devices and equipment in electric vehicles. In addition, Kapton® MT+ with CMC adhesive technology coatings ensures very good heat dissipation in the electronics area (e.g. charging device, battery management system and power electronics of the drive).
Insulation materials for hybrid and fully electric cars