Nanocrystal technology innovation with the rapid development of wireless charging

With the rapid development of wireless charging, wireless charging is now more and more popular in many industries such as smartphones, smart wearable devices, smart home systems, new energy vehicles, etc., and the sales market worth hundreds of billions of dollars has once again become a trend. However, there are many difficulties in wireless charging, which also cause headaches for those in the industry. The entire industry chain has been developing towards five major aspects: simplicity, fast charging, temperature control, intelligence, and playability.

Recently, mobile phone manufacturers such as Huawei have increased wireless charging power to 15W, which has greatly inspired the entire manufacturing industry. To maintain power wireless charging, wireless charging practitioners currently face many challenges, including: conversion efficiency between electromagnetic induction, increasingly tight magnetic coupling, magnetic interference, thermoelectric effects, position correction, and load adjustment. This will cause several problems such as the charging part of the wireless charging being unable to be pointed, the charging conversion efficiency being high, and the charging time being too long.

As one of the important components of wireless charging technology, Hemei Electronics plays the role of increasing the electromagnetic field and shielding the electromagnetic coil interference in wireless charging equipment. Therefore, wireless charging equipment has a certain influence on the performance and product specifications of permanent magnet materials, Credibility and other requirements are higher.

Although cross-generational products are eye-catching, being unique and fun is not the key to gaining sales. In the end, what customers still care about is their feelings.

Although wireless charging can improve the importance of user experience, it also has the problem of slow charging, so there is an urgent need to relatively increase charging power. However, the traditional ferrite core material has a serious problem of heating during wireless charging, and it can no longer meet the power charging requirements.

In comparison, nanocrystal materials contain various possibilities and have great potential for application in wireless charging in the future. Therefore, in wireless charging applications and RX module design, the advantages of nanocrystalline materials are fully demonstrated.

Nanocrystalline materials have various excellent comprehensive magnetic properties such as high saturation magnetic induction (), magnetic permeability >800, and poor high-frequency loss under high magnetic induction. They are the materials with the best comprehensive performance on the current market. Nowadays, nanocrystals rely on their advantages to excel in the testing of various important parameters of magnetic materials, gradually replacing ferrite cores and becoming the new choice of many wireless charging manufacturers.

According to statistics, the saturation magnetic induction of amorphous Nano-M-Sheet far exceeds that of ferrite cores, and its anti-saturation working ability far exceeds that of ferrite cores. The magnetic induction intensity of the Nano-M-Sheet raw material does not change greatly with temperature, it is not prone to magnetic saturation, and its temperature reliability is better than that of ferrite cores.

Aluminum alloy amorphous strip

In addition, the Nano-M-Sheet material has high saturation magnetic flux and low loss characteristics as well as excellent thermal conductivity. Under the same wireless charging working conditions, the temperature of the Nano-M-Sheet material is higher than that of ferrite. The core temperature is 7~8℃. In contrast, ferrite core materials are easy to reach saturation. When used in wireless charging, as the temperature rises, the magnetic induction decreases, the shielding properties decrease, the vortex increases, and the heating becomes more serious, resulting in polarization. The properties of the Nano-M-Sheet material are very stable below 80°C. As the temperature increases, although the magnetic induction decreases, the change is not significant.

Hemei Electronics is a technology company that integrates design, product development, manufacturing and sales of amorphous and nanocrystalline new soft magnetic materials and electronic devices. Its main business is nanocrystalline strips, ultra-microcrystalline magnetic cores, and permalloy. Magnetic cores, high-power transformer cores, nanocrystalline magnetic ring inductors, electromagnetic ring coils, switching transformers, common mode inductance coils, precision current transformers and other products have the advantages of good stability and high electrical parameters.

At this stage, the industrial production and processing technology of the company's amorphous nanocrystalline amorphous strips includes layer-by-layer processes such as smelting, tape spraying, tape feeding + inspection, and winding. At this stage, the quenching angular velocity exceeds ~30m/second. The thickness of the amorphous ribbon is 18~37um, and the total width of the amorphous ribbon is.

In order to meet new market challenges and comply with the market trend of high efficiency, low loss, and thin specifications, Hemei Electronics' next product development plan for amorphous will be in the promotion of nanocrystalline products, technological improvements, and new products. Development and design are carried out in three aspects.

In terms of research and development of nanocrystalline raw materials, Hc of soft magnetic materials is reduced and Bs is increased to improve alloy composition. For the current 18 μm thin nanocrystalline amorphous strip, we will reduce eddy current loss, increase the frequency bandwidth, and reduce the product thickness to 12~15 μm. By increasing the permeability and improving product consistency, the constant support force quenching target of nanocrystalline amorphous strips is exceeded 12,000~15,000.

According to statistics, when nanocrystalline amorphous ribbons undergo crystallization and constant support force quenching and tempering, magnetic anisotropy will occur, making the long and short directions of the ribbons become hard-to-magnetize axes, thereby controlling the magnetic permeability within a wide range. , producing nanocrystalline soft magnetic materials with different magnetic permeabilities. The characteristic of this low-permeability nanocrystalline soft magnetic material is that it has small eddy current loss and can suppress the decrease in magnetic permeability when higher frequencies coincide with electromagnetic fields. Therefore, it can be used in DC accumulation in high-frequency areas.

In terms of nanocrystalline amorphous strip free online insulation coating technology, amorphous will reduce losses, increase frequency bandwidth, and reduce product thickness to achieve technical improvements. In the future, Amorphous will also develop and design a soft magnetic powder based on cast film technology that can reduce eddy current losses, increase frequency bandwidth, and reduce product thickness to sub-μm level.