Insulating foils for high field strengths in busbars

Ahlhorn | 09.09.2020/XNUMX/XNUMX

The expansion of the charging infrastructure in Germany and the higher performance of electric vehicles pose new challenges for manufacturers of power rails, charging infrastructure and battery systems. High dielectric strength, resistance to partial discharge and small component sizes are the requirements of the automotive industry and system builders for charging stations for electric vehicles.

In the case of highly integrated components with high field strengths, the homogeneity of the layer to be applied is particularly important, since layer thickness fluctuations have a direct effect on the dielectric strength of the material. Dielectric strength is highly dependent on the diameter and dielectric properties of a material.

In the production of multi-layer current-carrying systems, foil technology is mainly used to insulate conductive layers. The foil technology is characterized by a high degree of homogeneity in the layer thickness. A high degree of homogeneity of the layer is necessary because air inclusions can lead to pre-discharges that ionize the surrounding air and thus make a breakdown more likely. In addition, surrounding insulating materials are permanently damaged by ultraviolet radiation.
The edge area in the foil technique must be reworked. The following methods are used for this:

open mold process

With the open-mold process, the insulator layers overlap the metal layer in the edge area, but do not enclose it, so that the full potential of the different current-carrying levels is present in the side area. Depending on the field strength applied, the air in the edge area is ionized, which leads to arcs or arcs at higher electric field strengths. can damage the material by ultraviolet radiation. The process is characterized by low production costs and is designed exclusively for use in control cabinets and dry areas of application with low field strengths.

potting

Similar to the open mold process, the insulator layer overlaps the metal layer in the edge area. The current-carrying planes are sealed by potting compound and subsequent edge processing. Problems can arise from air pockets leading to ultraviolet radiation damage to the insulator. Depending on the material, the process is designed for higher field strengths.

closed mold process

With the closed-mold process, the protruding foil is pressed and thus completely closes off the current-carrying levels on the sides. When closing the edge, it is important to avoid air pockets

Insulating foils from Dr. Depending on the process technology, Dietrich Müller GmbH enable a high degree of freedom in the manufacture of components. A high degree of freedom in design plays a role, particularly in the case of highly integrated high-performance systems. Examples for this are:

– Charging stations for electric vehicles and other charging infrastructure systems
– Power regulators, accumulators and charging systems for electric vehicles or hybrid vehicles
– Vehicle electronics for locomotives, trams and electric buses
– Wind turbines and offshore renewable energy installations
– High-current systems for aircraft
– Power electronics in computers, servers and telecommunication systems

the dr Dietrich Müller GmbH specializes in the manufacture of polyimide films , electrical insulating materials, thermally conductive products, seals and technical foils. The product portfolio includes flexible electrical insulation materials, prepregs, coated fabrics, adhesive tapes, laminates and profiles, thermally conductive products, technical foils, sealing materials, Mica- products and other product groups.
Materials from third-party suppliers as well as our own patented solutions are used to implement the orders. In addition to our own products, technical and consulting services are also offered.
The main target markets are the electronics, solar, automotive and cable industries as well as the construction of electric motors, transformers and generators.