Electrical measurement of solid dielectric materials

The purpose of this article is to review the electrical measurement techniques available for dielectrics at the beginning of the 21st century, in order to help engineers and researchers in their choice of materials and components for the systems they are considering, thanks to their electrical properties. Industrial problems linked to the reliability of solid dielectric materials (breakdown, ageing, service life, etc.) call for the most complete characterization possible, in order to define the limits of the component in its environment. On the research side, the fundamental aspects of conduction, heating, losses, partial discharges, dielectric breakdown and the accumulation of space charges over time are all questions posed to PhD students that cannot be answered without well-planned measurements.

First, we'll look at the theoretical aspects of measurable quantities, followed by details of the measurements themselves.

Over the last few decades, new electrical measurement techniques have been developed and adopted by the industrial world to provide a better understanding of dielectrics, which are key elements in the transport and storage of electrical energy, and in the reliability of electronic components. Given the growth and diversification of energy needs on the one hand, and the widespread worldwide development of communication technologies thanks to miniaturization on the other, these materials are becoming increasingly important both in the fields of research and on a societal level.

We will present the evolution of traditional measurement techniques, and then go on to fully develop new methods for characterizing the electrical charges present in these materials. These techniques are the focus of particular attention, as they change the way we think about "insulators". Linked to the material's microstructure, the accumulation of charges constitutes defects that limit the performance of dielectrics, as evidenced by the numerous publications and patents filed on this subject.

Today, several techniques are used and approved by industry.

In the bibliography, for each technique, we have classified publications chronologically to show changes over time.