The current frequency of the Qi standard for wireless charging is between 100-200k. At this frequency, the permeability of nanocrystalline is very close to that of cobalt-based amorphous, which is significantly higher than that of iron-based amorphous and ferrite. On the contrary, the loss is significantly lower than that of iron-based amorphous and ferrite.
Nanocrystals also have advantages in temperature applications. Nanocrystals are not only wider in application temperature than cobalt-based amorphous and ferrite, but the stability of nanocrystals is also significantly better than ferrite in the range of -40℃-120℃ body.
Nanocrystals also have obvious advantages in the design of magnetic materials. Nanocrystals can directional control magnetic permeability and anti-saturation magnetic field. The permeability of nanocrystals can be adjusted at will within 1,000-30000. The design of magnetic materials requires that under a specific working current, the magnetic saturation should not be reached. Once the magnetic saturation is reached, it will stop working. The nanocrystalline adjustable anti-saturation magnetic field can reach 30~350A/m, making the application range of wireless charging more width.
Comparison between several iron-based nanocrystals and iron-based amorphous, cobalt-based amorphous and ferrite: Saturation magnetic flux density: iron-based nanocrystals are significantly better than cobalt-based, except for slightly lower than iron-based amorphous Amorphous and ferrite;
Nanocrystalline is better than other materials in terms of coercivity, initial permeability, saturation magnetostriction coefficient, Curie temperature, and performance change rate. Therefore, nanocrystalline is the best soft magnetic material.
The development trend of nanocrystalline
As electronic products are developing in the direction of high frequency, energy saving, small size, and integration, the application frequency is also increasing, and strips are updated from generation to generation. From the original traditional tape-making process (current domestic production level) with a thickness of 22-30μm, now the tape has developed to the third and fourth generations. The advanced tape-making process (international advanced production level) can achieve 14-22μm. And mastered thinner belt making technology. The development trend of nanocrystalline ribbons is ultra-thin ribbons.
Ultra-thin nanocrystalline ribbon characteristics: the thinner the ribbon, the lower the loss.
The mass production process of magnetic conductive sheets has been reformed. Since the mass production of magnetic conductive sheets in 2015, the process has continued to change, gradually transitioning from sheet to coil, greatly improving production efficiency and meeting the growing demand.