What are the classifications of absorbing materials?
1. Resistive loss of the absorbing material. This kind of absorption mechanism is related to the resistive loss of the material’s conductivity, that is, the greater the conductivity, the macro current caused by carriers (including the current caused by the change of electric field and the eddy current caused by the change of magnetic field. ) Is larger, which is conducive to the conversion of electromagnetic energy into thermal energy.
2. The manufacturer of the absorbing material tells you that the rubbing action converts electromagnetic energy into heat and dissipates it. The dielectric polarization process includes: electron cloud displacement polarization, polar dielectric moment turning polarization, electric ferrite domain turning polarization, and wall displacement.
3. Magnetic loss. This type of absorption mechanism is a type of magnetic loss related to the dynamic magnetization process of ferromagnetic media. This type of loss can be refined into: hysteresis loss, gyromagnetic eddy current, damping loss and magnetic aftereffect, etc. The main sources are magnetic domain turning, magnetic domain wall displacement, and natural resonance of magnetic domains, which are similar to the hysteresis mechanism. In addition, the latest microwave loss mechanism of nanomaterials is a hot spot in the analysis of absorbing materials today.
What are the types of loss mechanisms of absorbing materials?
Absorbing material refers to a type of material that can absorb the electromagnetic wave energy projected on its surface. Classification of the loss mechanism of absorbing materials.
First, resistive loss, this type of absorption mechanism and resistive loss related to the conductivity of the material, that is, the greater the conductivity, the greater the macro current caused by carriers (including the current caused by the change of electric field and the eddy current caused by the change of magnetic field). Large, which is conducive to the conversion of electromagnetic energy into thermal energy.
Second, the dielectric loss, the absorbing material is a kind of dielectric loss absorption mechanism related to the electrode, that is, the electromagnetic energy is converted into heat by the "friction" effect generated by the repeated polarization of the medium and dissipated. The dielectric polarization process includes: electron cloud displacement polarization, polar dielectric moment turning polarization, electric ferrite domain turning polarization, and wall displacement.
Third, magnetic loss. This type of absorption mechanism is a type of magnetic loss related to the dynamic magnetization process of ferromagnetic media. This type of loss can be refined into: hysteresis loss, gyromagnetic eddy current, damping loss, and magnetic aftereffects, etc. Its main source is the magnetic domain turning, the displacement of the magnetic domain wall and the natural resonance of the magnetic domain, which are similar to the magnetic mechanism.
What is the installation method of the absorbing material?
The absorbing material is made of soft magnetic powder, resin and other raw materials according to a certain ratio of noise suppression magnetism
Thin film, with high magnetic permeability and soft texture. One side is covered with double-sided tape, as long as it is stuck in the right place.
Excellent noise suppression effect. So how to install the absorbing material?
1. The product can be pasted around the inner wall of the case to reduce the electromagnetic environment in the device, so that the individual components can operate in a relatively compatible electromagnetic environment;
2. Two high-speed chips interfere with each other or a chip interferes with the radiation of adjacent components. The absorber can be attached between the two ICs to suppress high-frequency interference;
3. The interface of the metal shielding cover is easy to leak electromagnetic radiation, and the product can be attached to the interface to absorb the leakage electric wave;
4. When the two PCB substrates are close or superimposed together, they are easily interfered by each other. At this time, it is necessary to attach the absorbing material to the substrate to directly isolate the interference and have an excellent effect;
5. Due to the dense arrangement of wires in the equipment, electromagnetic radiation is usually conducted to other harassed EMS components through these wires. We can stick the product on the flexible cable to effectively filter out high-frequency waves, or it can be wound in a circular shape. Suppress high frequency conduction on the wire;
6. The radiation of electromagnetic waves will eventually have radiation interference sources such as clock signal generators. You only need to stick the absorbing material on the interference source to weaken the interference radiation. In short, the occurrence of an interference will always be caused by the interference source and conduction interference. The path and the interference-sensitive components are composed of three elements, so only one of the three elements is required to apply the absorbing material to suppress the occurrence of interference to achieve EMC.