1. Features of magnetic materials:
Magnetic materials are mainly divided into permanent magnetic materials and soft magnetic materials. Permanent magnet materials are also called hard magnetic materials. The magnet can retain its strong magnetism for a long time after applying a magnetic field, and it is characterized by high coercivity (Hc). Generally its coercivity Hc≥10A4/m. The magnetic energy product (BH) max is large. Soft materials are magnetic materials that are easy to magnetize and demagnetize after applying a magnetic field. They are characterized by low coercive force, and generally their coercive force Hc≤10A3/m.
2. Four main magnetic properties of permanent magnet materials
(1) High maximum magnetic energy product The maximum magnetic energy product (BH) max is a measure of the maximum magnetic energy density stored and available per unit volume of a permanent magnetic material. (2) High coercive force Coercive force (Hc) is a measure of permanent magnetism maintained by the interference of magnetic and non-magnetic permanent magnet materials. (3) High residual magnetic flux density (Br) and high residual magnetization (Mr) are measures of the magnetic field strength in the air gap. (4) High stability refers to the high stability of external interference magnetic field, temperature, vibration and other environmental factors.
3. Main features of soft magnetic materials
(1) Low coercive force Hc: It shows that the magnetic material is easy to be magnetized by an external magnetic field, but also easy to be demagnetized by a magnetic field or other factors, and the magnetic loss is also low. (2) High saturation magnetic flux density Bs and high saturation magnetization Ms: In this way, Rong deliberately obtains high permeability and low coercivity Hc, which can also increase the magnetic flux density. (3) Low magnetic loss and electrical loss: This requires low coercivity Hc and high resistivity. (4) High stability: It has high stability against changes in environmental factors such as temperature and vibration.
Application classification of soft magnetic materials in 5G mobile phones
1. The application of NFC magnetic materials is mainly used for near-field non-contact induction and signal shielding. Conventional use of manganese-zinc ferrite and nickel-zinc ferrite
2. WPC magnetic material application is mainly used for wireless transmission of current. Ferrite magnetic sheet, nanocrystalline ribbon, etc.
3. The application of EMI magnetic materials is mainly used for the shielding and enhancement of mobile phone antenna signals. Ferrite magnetic materials such as magnetic rings and beads.