The development of the wireless charging industry is in full swing, and more and more wireless charging products have entered people’s lives. Today we are mainly talking about wireless charging ferrite sheet.
Ferrite sheet is a metal with high magnetic permeability and high loss. It is crystallized into a variety of soft magnetic alloys in ultra-fine molecules, laminated with layers of ribbon films, which can absorb microwaves generated by electronic components, modules and surface currents with high efficiency in a wide frequency range. Noise, improve performance, reduce temperature, and provide excellent EMC solutions for various electronic equipment.
Ferrite sheet is mainly divided into two types:
1. Hard magnetic sheet: Ferrite sheet sintered at high temperature has high magnetic permeability, and the material is hard and easy to crack. It is often used in the transmitter of wireless charging.
2. Soft magnetic sheet: Alloy magnetic powder is added to plastic or rubber, and then processed to form a soft magnetic sheet. The material of the soft magnetic sheet is relatively soft and the thickness is very thin. It can be punched according to the shape and size of the magnetic isolation sheet required by the wireless charging scheme.
So what is the main role of ferrite sheet in wireless charging products?
1. Magnetic permeability
As we all know, the principle of QI wireless charging standard is electromagnetic induction. When the primary coil (wireless charging transmitter) works, it will generate an interactive magnetic field (the direction of strength and weakness is constantly changing). In order to make the magnetic field energy emitted by the primary coil act on the secondary coil (wireless charging receiver) as much as possible, it is necessary to The magnetism of the coil conducts guidance.
2. Magnetic blocking
The magnetic sheet should not only be able to effectively conduct magnetism, but also play a role in blocking magnetism. Why block magnets? We know that when a changing magnetic field encounters a conductor such as a metal, a current will be generated if the metal is a closed wire, and if the metal is a non-closed wire, especially a solid piece of metal, an eddy current effect will occur. Eddy current will generate a lot of heat, just like an induction cooker, it uses the eddy current effect to convert electrical energy into heat energy. However, in wireless charging products, we should try to avoid the heating of the device as much as possible, because the heating not only consumes too much power, but also causes damage to the electronic equipment. In order to avoid heat generation, it is necessary to constrain the magnetic field generated at the transmitting end so that the magnetic field can only act on the coil at the receiving end, and cannot act on other devices outside the coil.
3. Heat dissipation
The magnetic field acts on the inductor coil to generate high-frequency current. During this process, the coil itself will also generate heat. If this heat is not effectively dissipated, it will accumulate. Sometimes we feel that the heat is very hot when wireless charging is carried out. It is generally caused by the heating of the inductor coil or the heating of the circuit board. In order to effectively conduct the heating of the coil and the circuit board, the packaging method is generally used: the coil, magnetic sheet, and circuit board are completely packaged with thermally conductive resin materials through a low-temperature and low-voltage IC packaging process, which can effectively dissipate heat. And achieve good cooling effect.
At present, the international competitive advantage of China’s soft magnetic material industry is mainly in the manufacturing link, and there is no overall breakthrough in the brand and technology links. The market competition is still mainly reflected in the competition of cost and price, which has not yet formed a healthy development; a few enterprises are competing for technological advantages in high-end products and the market, and the superior ones occupy the market and have the right to speak. With the increasing demand for soft magnetic materials and devices in new energy vehicles, wireless charging, photovoltaics, new infrastructure and other fields, it will open up new growth space for the soft magnetic material industry.
PH Functional Materials is a professional Wireless charging ferrite factory. The Wireless charging ferrite sheet we produce has magnetic and magnetic shielding functions, by attaching to the coil, increasing the coil inductance, reducing the heat caused by the metal eddy current resistance, the magnetic interference in the metal coil, Improve charging efficiency, safe and environmentally friendly, you can use it with confidence. If you want to know more about our products please consult our staff.