Magnetic conductive sheet for wireless charger and preparation method thereof

Abstract

The invention provides a magnetic conductive sheet for a wireless charger. The magnetic conductive sheet comprises a first magnetic thin sheet composed of a plurality of crushed and separated first magnetic fragments; each first magnetic fragment is stuck and positioned through an adhesion layer; a gap is formed between every two first magnetic fragments and the gap is filled with an air medium sothat all the first magnetic fragments are mutually insulated; a protection film is laminated on the surface side of the magnetic conductive sheet. The invention further provides a preparation methodof the magnetic conductive sheet. According to the magnetic conductive sheet provided by the invention, the air medium is used as an insulating medium of the magnetic conductive sheet and the application requirements of the magnetic conductive sheet in a wireless charging technology are met; meanwhile, the eddy-current effect can be effectively reduced; the magnetic conductive sheet has the technical advantages of good insulation treatment effect and simple preparation technology.

Description

technical field [0001] The invention relates to the technical field of wireless charging applications, in particular to a magnetically conductive sheet for a wireless charger and a preparation method thereof. Background technique [0002] Wireless charging is a technology that wirelessly charges the battery of the end-use device, and the power supply end and the power receiving end do not need to be physically connected. At present, electronic devices charged by electromagnetic induction are the most common in the market. [0003] Ultra-thin magnetic alloy materials such as amorphous or nanocrystalline ribbons with high magnetic permeability are used in the prior art. The thickness range of the single-layer magnetic alloy material is 10um-30um, which can be superimposed to improve the overall inductance of the material, and the structural design is more flexible and convenient. The magnetic permeability and saturation magnetic induction of amorphous magnetic alloy material...

AI Technical Summary

Problems solved by technology

[0004] The magnetic permeability and saturation magnetic flux density of amorphous magnetic alloy materials are ideal for wireless charging modules, but the wireless charging is an AC magnetic field, and the magnetic sheet works in the AC magnetic field. Loss, this part of the loss includes hysteresis loss, eddy current loss and other losses. Under the frequency of wireless charging, eddy current loss is an important part of the loss. Since the amorphous magnetic alloy material is a metal material, the resistivity is relatively low. If the material is not correct Further processing will generate serious eddy current loss on the amorphous magnetic alloy material during work, which will consume the working magnetic field and reduce the charging efficiency of wireless charging; in addition, when performing wireless charging, the unit area of ​​this magnetic alloy material is smaller. The larger the size, the easier it is to generate eddy current effects on a large area; therefore, it is necessary to fragment the magnetic alloy material, divide the large-area magnetic alloy material into small unitized magnetic fragments, and insulate each magnetic fragment from each other, thereby effectively reducing the Eddy effect

However, the preparation process of the magnetic permeable sheet in the prior art is complicated, and the insulation treatment effect is not good.

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