[Shielding material] According to the different purposes of shielding, the shielding body can be divided into electrostatic shielding body, magnetic shielding body and electromagnetic shielding body. The materials and functions of the three kinds of shielding bodies are as follows:
1. Electrostatic shield: It is made of inverse magnetic material (such as copper, aluminum) and connected to the ground. The function of the electrostatic shield is to terminate the electric field on the metal surface of the shield and transfer the charge to the ground.
2. Magnetic shielding body: It is made of strong magnetic material (such as steel) with high magnetic permeability, which can confine the magnetic field lines in the shielding body.
3. Electromagnetic shielding body: generally made of inverse magnetic materials (such as copper, aluminum), mainly used to contain the influence of high-frequency electromagnetic fields, so that the interference field forms eddy currents in the shielding body and at the interface between the shielding body and the protected space Reflects on the surface, which greatly weakens the field strength value of the interference field in the protected space and achieves the shielding effect. Sometimes in order to enhance the shielding effect, a multi-layer shielding body can also be used. The outer layer is generally made of high-conductivity materials to increase reflection, and the inner layer is made of high-permeability materials to increase the eddy current effect.