In recent years, electronic instruments have developed in the direction of "light, thin, short, small" and multi-functional, high-performance and low-cost. Therefore, plastic cases, plastic parts or boards are widely used in electronic instruments, so external electromagnetic waves can easily penetrate the shell or board and cause harmful interference to the normal operation of the instrument. The electromagnetic waves generated by the instrument are also very easy to radiate. The surrounding space affects the normal operation of other electronic instruments.
In order to make this electronic instrument meet the electromagnetic compatibility requirements, in practice, people have developed plastic metallization methods, such as sputtering galvanizing, vacuum AL plating, electroplating or electroless copper plating with metal foil (Cu or AL And coating conductive paint, etc. After metallization, the completely insulated plastic surface or the plastic itself (conductive plastic) has the reflection of metal (such as mobile phones). It absorbs, conducts and attenuates electromagnetic waves, thereby shielding electromagnetic waves. The effect of interference. In practical applications, conductive paint is used as a shielding coating, which has excellent performance and reasonable price. In the place where shielding is needed, a closed conductive shell is made and grounded to isolate the two different electromagnetic waves inside and outside. Practice. It shows that when selecting the route of the high-voltage line, it is necessary to avoid the radio station (station) or make full use of the terrain and ground shielding of the receiving area; the receiving equipment and the interference source equipment should be properly configured to keep the receiving equipment and various interference sources away from a certain distance; In the design of microwave communication circuits, in order to reduce interference, the antenna height can be used to adjust the reflection point of the microwave circuit, and the hilltop can be used to block the reflected wave so that it cannot interfere with the direct wave. In addition, the microwave tower is an independent tall building. Thorough grounding, shielding and other lightning protection measures should be adopted.