The use of shielding cover in WIFI-hardware

The main function of the shielding cover: Use the shielding cover to surround the interference sources of components, circuits, assemblies, cables or the entire system to prevent the interference electromagnetic field from spreading; use the shielding body to surround the receiving circuit, equipment or system to prevent them from being affected The influence of external electromagnetic fields. To a certain extent, the components are protected from dust and the service life is prolonged. Material composition: Stainless steel, nickel silver and tinplate are mainly used as materials. Among them, nickel silver is a metal shielding material that is easy to be tinned. Technical principle: Because the shielding cover plays the role of absorbing energy (eddy current loss), reflecting energy (two interface reflections of electromagnetic waves on the shielding body) and canceling energy (electromagnetic induction is generated on the shielding layer). The reverse electromagnetic field can cancel part of the interference electromagnetic wave), so the shield has the function of reducing the interference. When the frequency of the interfering electromagnetic field is high, the eddy current generated in the metal material with low resistivity is used to form the cancellation effect of the external electromagnetic wave, so as to achieve the shielding effect. When the frequency of interfering electromagnetic waves is low, materials with high magnetic permeability should be used, so that the lines of magnetic force are limited to the inside of the shield and prevent spreading to the shielded space. In some occasions, if a good shielding effect is required for both high-frequency and low-frequency electromagnetic fields, different metal materials are often used to form a multilayer shield. Packaging method: Tray or tape and reel packaging, using automatic surface laminating machine, can be quickly mounted on the PCB. The shielding effect is good, the inside of the cover can be electrically insulated, the general shielding effect is 40~55Db/100MHz~1GHz, in line with ROSH