How effectively do materials shield against transient electric fields?

Two aspects of shielding are of practical significance. (1) The ability of materials to provide shielding against fast electric field transients. This shielding is particularly relevant to protecting sensitive semiconductor devices and microelectronic assemblies during carriage through environments where the electrostatic conditions cannot be controlled. It is also relevant to protect the operation of microelectronic systems against upset by spurious signals and to shield equipment against the reception or emission of electromagnetic radiation at particular frequencies. (2) The maximum rate of charge movement in materials is relevant to the opportunity to draw sparks and cause ignition of flammable gases. This article shows how the electric field shielding performance of materials may be measured in a way that is fair to various types and constructions of materials and provides information by which the suitability of materials may be judged for various practical applications. This new noninvasive method measures the ability of materials to provide shielding against electrostatic discharges.