What Is an Electromagnetic Shielding Sheet?
An electromagnetic shielding sheet, as the name suggests, is a sheet for shielding. What it shields is certain electromagnetic waves. Electromagnetic waves can have a negative impact on electrical equipment in use, and in the worst case, can cause malfunctions or equipment operation to run out of control, potentially resulting in significant damage to the user. In order to suppress such adverse effects, the international standard IEC worldwide regulate the noise levels, such as noise terminal voltage and disturbance power, generated by electronic equipment in use, and these are the main countermeasure items.
Uses of Electromagnetic Shielding Sheets
Electromagnetic shielding sheets are mainly used to suppress the electromagnetic waves emitted by electronic equipment in general, including information devices such as smartphones and PCs that operate with high-speed clock processing, when the electromagnetic waves they emit exceed the regulation values, or when they are at risk of malfunctioning due to external noise. Electromagnetic shielding sheets can also be used to block problems caused by electromagnetic waves in high-energy, high-voltage AC power lines, electrical substation facilities, and large transmitting and receiving devices such as cell phone base stations that are engaged in high-speed communications.
Principle of Electromagnetic Shielding Sheets
The principle of electromagnetic shielding sheet is that when soft magnetic materials with a nano-level crystal structure are piled up in layers, electromagnetic waves in the frequency band of 1 gigahertz or lower are shielded. Shield sheets are made from this property.
In particular, the Hitachi Metals’ electromagnetic shielding sheet has excellent shielding performance even in the low frequency band below several hundred kilohertz, which is relatively difficult to counteract. Furthermore, by increasing the number of layers, it is possible to shield even stronger magnetic fields, and to reduce the deterioration of magnetic shielding performance due to processing such as bending, punching, and cutting. Long rolls are ideal for large-scale applications such as shield rooms. The principle of electromagnetic shielding is to reduce electromagnetic energy by reflection, absorption, and multiple reflection of electromagnetic waves. By reducing electromagnetic waves, hazards to the human body and effects on precision equipment can be avoided. Electromagnetic waves, like light, travel in a straight line and are diffracted. When installing shielding materials, it is necessary to pay attention to the arrival of electromagnetic waves due to their wraparound effect.