WO2022134622A1 - Nanocrystalline magnetically-conductive sheet for wireless power charging and near field communication, and manufacturing method therefor - Google Patents

Abstract

The present invention relates to the technical field of magnetic materials. Disclosed are a nanocrystalline magnetically-conductive sheet for wireless power charging and near field communication, and a manufacturing method therefor. A nanocrystalline strip is subjected to heat treatment, coated with a protective film, and then subjected to longitudinal roll shearing treatment to obtain a nanocrystalline magnetically-conductive sheet having uniform longitudinal shearing lines which are arranged in form of bars; a central region and a peripheral shielding region are marked on the obtained nanocrystalline magnetically-conductive sheet, and the peripheral shielding region is subjected to secondary mold pressing and crushing to obtain a magnetic permeability lower than that of the magnetically-conductive sheet at the central region, thereby obtaining a nanocrystalline magnetically-conductive sheet for wireless power charging and near field communication. According to the present invention, two different magnetic permeability properties are obtained on the same nanocrystalline magnetically-conductive sheet. The central region is a high magnetic permeability region to implement a wireless power charging function, and the peripheral shielding region is a low magnetic permeability region to implement a near field communication function. A magnetic shielding material is used to implement a solution for optimization of wireless power charging and near field communication functions.

Description

Nanocrystalline magnetic conductive sheet for wireless charging and near field communication and preparation method thereof technical field

The invention belongs to the technical field of magnetic materials, and in particular relates to a nanocrystalline magnetic conductive sheet for wireless charging and near-field communication and a preparation method thereof.

Background technique

In recent years, with the popularity of wireless charging technology (Wireless Power Charging, WPC) and Near Field Communication technology (Near Field Communication, NFC) in the field of consumer electronics, especially in mobile phones, more and more mobile phone products have begun to come standard with these two technologies. In particular, Samsung Electronics has integrated these two functions on the mobile phone module side since the Galaxy S6 mobile phone. In addition, it has also integrated the mobile payment function (MST), which is the well-known 3-Combo technology in the market. Flagship models (S series and Note series) have continued to use this technology. Due to the different working frequencies of the wireless charging (WPC) function and the near field communication (NFC) function, the working frequency of WPC is 100-200kHz, and the working frequency of NFC is 13.56MHz, which determines the application of these two applications to magnetic materials. Performance requirements vary. The WPC function focuses on the higher the magnetic permeability of the magnetic material, the better, so that the electromagnetic field can be bound to the maximum, the charging efficiency can be improved as much as possible, and the interference of the magnetic field to the outside world can be shielded. The NFC function focuses on the lower the magnetic loss of the magnetic material, the better, so that the attenuation of the signal during high-frequency transmission will be less, and the sensitivity of the signal induction will be enhanced. In practical applications, the magnetic permeability and magnetic loss of magnetic materials are a relatively contradictory set of properties, that is, the higher the magnetic permeability of the material, the greater the magnetic loss. Conductivity. Therefore, in the actual application of wireless charging and near-field communication, it is often necessary to choose two different magnetic materials to meet the above two functions. Samsung Electronics originally used amorphous materials in 3-Combo technology to realize wireless charging. function, and the ferrite material is used to realize the near field communication function. Then Samsung Electronics updated the magnetic shielding material technology, only using nanocrystalline magnetic shielding material to realize wireless charging and near-field communication functions at the same time, but in fact, due to the difference in the frequency of the application of these two functions, the solution of this nanocrystalline material is only A compromise implementation solution, that is, sacrificing part of the wireless charging and near-field communication functions, that is to say, in the nanocrystalline solution, neither the wireless charging function nor the near-field communication function has been optimally implemented.

In the previously published patents, such as patent CN 105336465 A, a composite magnetic conductive sheet for wireless charging and near-field communication and a preparation method thereof are disclosed. A method for preparing a functional composite magnetic conductive sheet. Specifically, it is mentioned in the patent that the composite magnetic conductive sheet includes an uppermost layer material, an intermediate layer material and a lowermost layer material, wherein the uppermost layer material and the lowermost layer material are composite sheets composed of soft magnetic powder and resin material; the The material of the intermediate layer is at least one layer of magnetic metal flakes or a composite flake composed of magnetic metal flakes, soft magnetic powder and resin material, and one or both sides of the magnetic metal flakes are adhered with double-sided tape; the uppermost layer The material, the material of the middle layer and the material of the lowermost layer are formed at one time after hot pressing. The patent mentions that when the NFC communication function is performed, sufficient magnetic permeability is provided to ensure sufficient communication distance to meet the requirements of near-field communication; at the same time, the NFC communication function is prevented from causing interference to other processors, and accordingly, other The processor interferes with the NFC antenna itself. However, this preparation method is still only a supplementary optimization of the nanocrystalline material scheme. Two magnetic shielding materials are used to meet the working requirements of WPC and NFC in two different frequency bands. It is still impossible to use one magnetic shielding material to realize wireless charging and The NFC function optimization solution does not fundamentally solve how the functions of two different application frequencies can achieve the best performance in their respective application frequency bands.

Patent CN 109243755 A discloses a wide-band composite magnetic isolation sheet and a preparation method thereof. Through the multi-layer alternating structure of nanocrystalline flakes and Y ₂ Co _17-x M _x flakes, the cut-off frequency of the obtained magnetic barrier sheet is higher than 8 GHz, and the initial magnetic permeability is greater than 20, which can be compatible with wireless applications from KHz to GHz at the same time. However, the patent still uses a combination of nanocrystalline flakes and Y ₂ Co _17-x M _x flakes, and a magnetic shielding material cannot be used to achieve optimal solutions for wireless charging and near-field communication functions.

Other domestic patent disclosure information shows that at present, the research on the magnetic materials for wireless charging and near-field communication are amorphous, nanocrystalline magnetic conductive materials and ferrite materials respectively, and the use of the same material to achieve two functions has not been considered. complex. If two materials are used to solve the combination of the above two functions, on the one hand, there is no way to further reduce the cost of the materials, and on the other hand, it also brings certain difficulties to the subsequent assembly and processing technology.

SUMMARY OF THE INVENTION

In view of the above shortcomings and deficiencies in the prior art, the primary purpose of the present invention is to provide a preparation method of a nanocrystalline magnetic conductive sheet for wireless charging and near field communication.

Another object of the present invention is to provide a nanocrystalline magnetic conductive sheet prepared by the above method.

The object of the present invention is achieved through the following technical solutions:

A preparation method of a nanocrystalline magnetic conductive sheet for wireless charging and near-field communication, comprising the following preparation steps:

(1) heat treatment of the nanocrystalline strip, and then cover the surface of the nanocrystalline strip with a protective film;

(2) subjecting the nanocrystalline strip covered with the protective film in step (1) to a longitudinal roll shearing treatment to obtain a nanocrystalline magnetic conductive sheet with uniform longitudinal stripe pattern splits;

(3) marking the central area and the peripheral shielding area for the nanocrystalline magnetic conductive sheet obtained in step (2);

(4) performing secondary molding and crushing on the outer shielding area of the nanocrystalline magnetic conductive sheet obtained in step (3) to obtain a magnetic permeability lower than that of the magnetic conductive sheet in the central area to obtain the nanocrystalline conductive sheet for wireless charging and near-field communication. Magnetic flakes.

Further, the nanocrystalline tape in step (1) is an iron-based nanocrystalline tape with a thickness of 7-28 μm. The preferred composition is Fe-Cu-Nb-Si-B.

Further, the heat treatment temperature in step (1) is 500-650°C, preferably the temperature range is 560-630°C; the heat-treatment atmosphere is nitrogen, hydrogen or vacuum.

Further, the protective film material in step (1) is any one of PET, PE, OPP, PVC, CPP or BOPP.

Further, in the step (2), the width of the longitudinal stripe-shaped lines is 0.5-2mm (the distance between adjacent stripe-shaped lines), and the magnetic permeability of the obtained nanocrystalline magnetic conductive sheet at a frequency of 100kHz is 3000～2mm. 6000 (relative permeability).

Further, in step (3), the area of the central region is 1200-3600 mm ² , and the area of the peripheral shielding region is 500-3000 mm ² .

Further, in step (3), the shape of the central area is a circle or a rectangle, and the boundary of the peripheral shielding area is a rectangle.

Further, in step (4), the magnetic permeability of the peripheral shielding area after being crushed by secondary molding is less than 500 (@100kHz).

Further, the nanocrystalline magnetic conductive sheet obtained in step (4) is further laminated in multiple layers to obtain a multi-layered nanocrystalline magnetic conductive sheet, and a heat dissipation layer is attached to the outermost layer of the multi-layered nanocrystalline magnetic conductive sheet.

Further, the heat dissipation layer is graphite, thermal conductive adhesive or a composite layer of the two.

A nanocrystalline magnetic conductive sheet for wireless charging and near field communication is prepared by the above method; the central area of the nanocrystalline magnetic conductive sheet realizes the wireless charging function, and the peripheral shielding area realizes the near field communication function.

The principle of the invention is: using the influence of the fragmentation degree of the nanocrystalline magnetic conductive sheet on the magnetic permeability, the nanocrystalline magnetic conductive sheet is divided into a central area and a peripheral shielding area, and the central area has a lower fragmentation degree and thus has a higher The magnetic permeability is used to realize the WPC function, which has the effect of improving the charging efficiency and shielding the magnetic field from the external interference; the peripheral shielding area is crushed by secondary molding to obtain a higher degree of fragmentation, so it has a lower magnetic permeability than the central area. The magnetic permeability is used to realize the NFC function, with lower magnetic loss and stronger signal induction sensitivity. The composite of two functions on the same material is realized, the preparation cost of the material is significantly reduced, and the subsequent assembly and processing process is simplified.

The preparation method of the present invention and the obtained product have the following advantages and beneficial effects:

(1) The preparation method of the present invention realizes obtaining two different magnetic permeability properties on the same nanocrystalline magnetic conductive sheet, wherein the central area of the nanocrystalline magnetic conductive sheet is a high magnetic permeability area, and the wireless charging coil is placed in the center Zones can greatly improve the efficiency of wireless charging and maximize the shielding of electromagnetic fields from the outside world. The surrounding shielding area of the central area is a low magnetic permeability area, which can obtain low magnetic loss characteristics. Placing the near-field communication coil in this shielding area can improve the induction sensitivity of the coil and obtain an excellent communication experience.

(2) The preparation method of the present invention only needs to perform longitudinal roll shearing treatment on the nanocrystalline strip, so that high magnetic permeability in the central area can be obtained, and low magnetic permeability can be obtained by secondary molding and crushing of the peripheral shielding area, thereby reducing the magnetic shielding. The magnetic loss of the material does not require transverse shearing or multiple crushing, which significantly improves the production efficiency and improves the performance consistency and stability of the nanocrystalline magnetic conductive sheet.

(3) The size and shape of the central area and the peripheral shielding area of the nanocrystalline magnetic conductive sheet of the present invention can be well matched with the matching FPC coil, so that the functions of wireless charging and near field communication can be optimally embodied at the same time.

Description of drawings

FIG. 1 is a schematic structural diagram of a nanocrystalline magnetic conductive sheet for wireless charging and near-field communication according to Embodiment 1 of the present invention.

FIG. 2 is a schematic structural diagram of a nanocrystalline magnetic conductive sheet for wireless charging and near-field communication according to Embodiment 2 of the present invention.

Detailed ways

The present invention will be described in further detail below with reference to the embodiments and the accompanying drawings, but the embodiments of the present invention are not limited thereto.

Example 1

A schematic diagram of the structure of a nanocrystalline magnetic conductive sheet for wireless charging and near-field communication in this embodiment is shown in FIG. 1 . The nanocrystalline magnetic conductive sheet for wireless charging and near-field communication includes a central area for realizing wireless charging function and a peripheral shielding area for realizing near-field communication function. The central area is a circle with a diameter of 50mm, and the boundary of the peripheral shielding area is a rectangle with a length and width of 70mm. The central area is a uniform longitudinal stripe pattern with a width of 1mm, and the magnetic permeability of the central area at a frequency of 100kHz is 4500; The permeability is 450.

The nanocrystalline magnetic conductive sheet for wireless charging and near field communication of this embodiment is prepared by the following method:

(1) Heat treatment of Fe-Cu-Nb-Si-B nanocrystalline tapes (thickness of 25 μm) in nitrogen atmosphere at a heat treatment temperature of 560°C, and then cover the surface of the nanocrystalline tapes with a PET protective film.

(2) The nanocrystalline tape covered with the protective film in step (1) is subjected to longitudinal (along the length direction of the tape) roll shearing treatment to obtain a nanocrystalline magnetic conductive sheet with a uniform longitudinal stripe pattern with a width of 1 mm.

(3) Marking a central area and a peripheral shielding area for the nanocrystalline magnetic conductive sheet obtained in step (2); the central area is a circle with a diameter of 50 mm, and the boundary of the peripheral shielding area is a rectangle with a length and width of 70 mm.

(4) The outer shielding area of the nanocrystalline magnetic conductive sheet obtained in step (3) is subjected to secondary molding and crushed into uniform grid-like fragments to obtain the nanocrystalline magnetic conductive sheet for wireless charging and near-field communication.

The magnetic permeability of the central region of the nanocrystalline magnetic conductive sheet obtained by the above method is 4500 at a frequency of 100 kHz;

The nanocrystalline magnetic conductive sheet obtained in this example is laminated in four layers, and a graphite sheet heat dissipation layer is laminated on the outermost layer. The wireless charging and near-field communication performance tests were carried out on the obtained multilayer nanocrystalline magnetic conductive sheet:

Among them, the wireless charging performance test is the charging efficiency test, using a 15W Qi standard wireless charging module as the transmitter, and Comparative Example 1 is the use of the published patent method (201610096632.1 A flexible magnetic conductive sheet for non-contact charging and its preparation method) ) is a receiver module composed of a 4-layer nanocrystalline magnetic sheet and a receiver coil, and the magnetic permeability of the relevant magnetic sheet is 720. Connect the receiving end modules of the above-mentioned Example 1 and Comparative Example 1 to the lithium-ion battery, and test the voltage and current of the input end and the output voltage and current of the receiving end when a voltage is applied to the coil of the transmitting device. The data recording and charging efficiency calculation results of the examples are shown in Table 1. It can be seen from the results in Table 1 that the charging efficiency of Example 1 is 2.32% higher than that of Comparative Example 1, indicating that the nanocrystalline magnetic flakes with high magnetic permeability obtained by the process method involved in the present invention are different from those of the published patents. Compared with the nanocrystalline magnetic flakes with low magnetic permeability prepared by the method, the charging efficiency is significantly improved. This is mainly because the high magnetic permeability improves the inductance of the receiving end module and enhances the coupling ability of the transmitting coil and the receiving coil, thereby increasing the ability of the receiving coil to bind the magnetic field lines. In addition, the outer shielding area of the nanocrystalline magnetic sheet is broken The degree of cracking is more obvious and the magnetic permeability is lower, thereby reducing the eddy current loss generated after the magnetic force line passes through the magnetic sheet. Considering two factors, the high magnetic permeability nanocrystalline magnetic sheet prepared by the method of the present invention is very useful for improving wireless The efficiency of charging has a significant effect.

Table 1

The NFC sensing distance of Example 1 was tested by using the NFC-TAG module. Comparative Example 2 was a mass-produced ferrite magnet for NFC with the same thickness on the market, and its magnetic permeability was 180. Table 2 shows the test results. From the test results, the sensing distances of tag 2 and tag 4 show that the nanocrystalline scheme of Example 1 is the same as the ferrite scheme, and the sensing distances of tag 1 and tag 3 show that the sensing distance of the ferrite scheme is larger, but the The nanocrystalline solution can basically meet the performance requirements of NFC.

Table 2

	tag1	tag2	tag3	tag4
Comparative Example 2	40mm	45mm	40mm	30mm
Example 1	35mm	45mm	35mm	30mm

It can be clearly seen from the results in Table 1 and Table 2 that the nanocrystalline magnetic conductive sheet of the present invention can simultaneously realize excellent wireless charging and near field communication functions on a nanocrystalline tape.

Example 2

A schematic diagram of the structure of a nanocrystalline magnetic conductive sheet for wireless charging and near-field communication in this embodiment is shown in FIG. 2 . The nanocrystalline magnetic conductive sheet for wireless charging and near-field communication includes a central area for realizing wireless charging function and a peripheral shielding area for realizing near-field communication function. The central area is a rectangle with a length and width of 60mm, and the boundary of the peripheral shielding area is a rectangle with a length and width of 80mm. The central area is a uniform longitudinal stripe pattern with a width of 0.5mm, and the magnetic permeability of the central area at a frequency of 100kHz is 3000; the peripheral shielding area is a grid-like fracture with a uniform width of 0.5mm, and the peripheral shielding area is 100kHz. The frequency has a permeability of 300.

The nanocrystalline magnetic conductive sheet for wireless charging and near field communication of this embodiment is prepared by the following method:

(1) Heat treatment of Fe-Cu-Nb-Si-B nanocrystalline tapes (thickness of 18 μm) under nitrogen atmosphere at a heat treatment temperature of 600°C, and then cover the surface of the nanocrystalline tapes with a PVC protective film.

(2) The nanocrystalline tape covered with the protective film in step (1) is subjected to longitudinal roll shearing treatment to obtain a nanocrystalline magnetic conductive sheet with a uniform longitudinal stripe pattern of 0.5 mm in width.

(3) Marking a central area and a peripheral shielding area for the nanocrystalline magnetic conductive sheet obtained in step (2); wherein the central area is a rectangle with a length and width of 60 mm, and the boundary of the peripheral shielding area is a rectangle with a length and width of 80 mm.

(4) The outer shielding area of the nanocrystalline magnetic conductive sheet obtained in step (3) is subjected to secondary molding and crushed into uniform grid-like fragments to obtain the nanocrystalline magnetic conductive sheet for wireless charging and near-field communication.

The magnetic permeability of the central region of the nanocrystalline magnetic conductive sheet obtained by the above method is 3000 at a frequency of 100 kHz;

The nanocrystalline magnetic conductive sheet obtained in this example is laminated in four layers, and a graphite sheet heat dissipation layer is laminated on the outermost layer. The wireless charging and near-field communication performance tests were carried out on the obtained multilayer nanocrystalline magnetic conductive sheet:

Among them, the wireless charging performance test is the charging efficiency test, using a 15W Qi standard wireless charging module as the transmitter, and Comparative Example 1 is the use of the published patent method (201610096632.1 A flexible magnetic conductive sheet for non-contact charging and its preparation method) ) is a receiver module composed of a 4-layer nanocrystalline magnetic sheet and a receiver coil, and the magnetic permeability of the relevant magnetic sheet is 720. Connect the receiving end modules of the above-mentioned embodiment 2 and comparative example 1 to the lithium-ion battery, and test the voltage and current of the input end and the output voltage and current of the receiving end when a voltage is applied to the coil of the transmitting device. The data records and charging efficiency calculation results of the examples are shown in Table 3. It can be seen from the results in Table 3 that the charging efficiency of Example 2 is 2.52% higher than that of Comparative Example 1, indicating that the nanocrystalline magnetic flakes with high magnetic permeability obtained by the process method involved in the present invention are different from the published patents. Compared with the nanocrystalline magnetic flakes with low magnetic permeability prepared by the method, the charging efficiency is significantly improved. This is mainly because the high magnetic permeability improves the inductance of the receiving end module and enhances the coupling ability of the transmitting coil and the receiving coil, thereby increasing the ability of the receiving coil to bind the magnetic field lines. In addition, the outer shielding area of the nanocrystalline magnetic sheet is broken The degree of cracking is more obvious and the magnetic permeability is lower, thereby reducing the eddy current loss generated after the magnetic force line passes through the magnetic sheet. Considering two factors, the high magnetic permeability nanocrystalline magnetic sheet prepared by the method of the present invention is very useful for improving wireless The efficiency of charging has a significant effect.

table 3

Using the NFC-TAG module to test the NFC sensing distance of Example 2, Comparative Example 2 is a mass-produced ferrite magnet for NFC with the same thickness on the market, and its permeability is 180. Table 4 shows the test results. From the test results, the sensing distances of tag 2 and tag 4 show that the nanocrystalline scheme of Example 1 is the same as the ferrite scheme, and the sensing distances of tag 1 and tag 3 show that the sensing distance of the ferrite scheme is larger. The nanocrystalline solution can also basically meet the performance requirements of NFC.

Table 4

	tag1	tag2	tag3	tag4
Comparative Example 2	40mm	45mm	40mm	30mm
Example 2	35mm	45mm	33mm	30mm

It can be clearly seen from the results in Tables 3 and 4 that the nanocrystalline magnetic conductive sheet of the present invention can simultaneously realize excellent wireless charging and near field communication functions on a nanocrystalline tape.

Example 3

A nanocrystalline magnetic conductive sheet for wireless charging and near field communication in this embodiment includes a central area for realizing wireless charging function and a peripheral shielding area for realizing near field communication function. The central area is a circle with a diameter of 40mm, and the boundary of the peripheral shielding area is a rectangle with a length and width of 50mm. The central area is a uniform longitudinal stripe pattern with a width of 2mm, and the magnetic permeability of the central area at a frequency of 100kHz is 6000; The permeability is 500.

The nanocrystalline magnetic conductive sheet for wireless charging and near field communication of this embodiment is prepared by the following method:

(1) The Fe-Cu-Nb-Si-B nanocrystalline ribbon (thickness is 14 μm) is heat-treated in a nitrogen atmosphere, and the heat-treatment temperature is 630°C, and then the surface of the nanocrystalline ribbon is covered with a BOPP protective film.

(2) The nanocrystalline tape covered with the protective film in step (1) is subjected to longitudinal roll shearing treatment to obtain a nanocrystalline magnetic conductive sheet with a uniform longitudinal stripe pattern of 2 mm in width.

(3) Marking a central area and a peripheral shielding area for the nanocrystalline magnetic conductive sheet obtained in step (2); the central area is a circle with a diameter of 40 mm, and the boundary of the peripheral shielding area is a rectangle with a length and width of 50 mm.

(4) The outer shielding area of the nanocrystalline magnetic conductive sheet obtained in step (3) is subjected to secondary molding and crushed into uniform grid-like fragments to obtain the nanocrystalline magnetic conductive sheet for wireless charging and near-field communication.

The magnetic permeability of the central region of the nanocrystalline magnetic conductive sheet obtained by the above method is 6000 at a frequency of 100 kHz;

The nanocrystalline magnetic conductive sheet obtained in this example is laminated in 5 layers, and a thermally conductive adhesive heat dissipation layer is laminated on the outermost layer. The wireless charging and near-field communication performance tests were carried out on the obtained multilayer nanocrystalline magnetic conductive sheet:

Among them, the wireless charging performance test is the charging efficiency test, using a 15W Qi standard wireless charging module as the transmitter, and Comparative Example 3 is the use of the published patent method (201610096632.1 A flexible magnetic conductive sheet for non-contact charging and its preparation method) ) is a receiver module formed by combining the 5-layer nanocrystalline magnetic sheet and the receiver coil, and the magnetic permeability of the relevant magnetic sheet is 750. Connect the receiving end modules of the above-mentioned embodiment 3 and comparative example 3 to the lithium-ion battery, and test the voltage and current of the input end and the output voltage and current of the receiving end when a voltage is applied to the coil of the transmitting device. The data records and charging efficiency calculation results of the examples are shown in Table 5. It can be seen from the results in Table 5 that the charging efficiency of Example 3 is 1.82% higher than that of Comparative Example 3, indicating that the nanocrystalline magnetic flakes with high magnetic permeability obtained by the process method involved in the present invention are different from the published patents. Compared with the nanocrystalline magnetic flakes with low magnetic permeability prepared by the method, the charging efficiency is significantly improved. This is mainly because the high magnetic permeability improves the inductance of the receiving end module and enhances the coupling ability of the transmitting coil and the receiving coil, thereby increasing the ability of the receiving coil to bind the magnetic field lines. In addition, the outer shielding area of the nanocrystalline magnetic sheet is broken The degree of cracking is more obvious and the magnetic permeability is lower, thereby reducing the eddy current loss generated after the magnetic force line passes through the magnetic sheet. Considering two factors, the high magnetic permeability nanocrystalline magnetic sheet prepared by the method of the present invention is very useful for improving wireless The efficiency of charging has a significant effect.

table 5

The NFC sensing distance of Example 3 was tested by using the NFC-TAG module. Comparative Example 4 was a mass-produced ferrite magnet for NFC with the same thickness on the market, and its permeability was 150. Table 6 shows the test results. From the test results, the sensing distances of tag 1, tag 2 and tag 4 show that the nanocrystalline scheme of Example 1 is the same as the ferrite scheme, and the sensing distance of tag 3 shows that the sensing distance of the ferrite scheme is slightly larger. The NFC performance of the crystal solution is basically close to the performance of ferrite.

Table 6

	tag1	tag2	tag3	tag4
Comparative Example 4	40mm	45mm	40mm	30mm
Example 3	40mm	45mm	38mm	30mm

It can be clearly seen from the results in Tables 5 and 6 that the nanocrystalline magnetic conductive sheet of the present invention can simultaneously realize excellent wireless charging and near field communication functions on a nanocrystalline tape.

The above-mentioned embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited by the above-mentioned embodiments, and any other changes, modifications, substitutions, combinations, The simplification should be equivalent replacement manners, which are all included in the protection scope of the present invention.

Claims (10)

1. A preparation method of a nanocrystalline magnetic conductive sheet for wireless charging and near-field communication, which is characterized by comprising the following preparation steps:

   (1) heat treatment of the nanocrystalline strip, and then cover the surface of the nanocrystalline strip with a protective film;

   (2) subjecting the nanocrystalline strip covered with the protective film in step (1) to a longitudinal roll shearing treatment to obtain a nanocrystalline magnetic conductive sheet with uniform longitudinal stripe pattern splits;

   (3) marking the central area and the peripheral shielding area for the nanocrystalline magnetic conductive sheet obtained in step (2);

   (4) performing secondary molding and crushing on the outer shielding area of the nanocrystalline magnetic conductive sheet obtained in step (3) to obtain a magnetic permeability lower than that of the magnetic conductive sheet in the central area to obtain the nanocrystalline conductive sheet for wireless charging and near-field communication. Magnetic flakes.
2. The method for preparing a nanocrystalline magnetically conductive sheet for wireless charging and near-field communication according to claim 1, wherein the nanocrystalline strip in step (1) is an iron-based nanometer with a thickness of 7-28 μm. crystal strip.
3. The method for preparing a nanocrystalline magnetic conductive sheet for wireless charging and near-field communication according to claim 1, wherein the heat treatment temperature in step (1) is 500-650°C, and the heat treatment atmosphere is nitrogen and hydrogen. Or vacuum.
4. The method for preparing a nanocrystalline magnetic conductive sheet for wireless charging and near-field communication according to claim 1, wherein the protective film material in step (1) is PET, PE, OPP, PVC, CPP or Any of BOPP.
5. The method for preparing a nanocrystalline magnetic conductive sheet for wireless charging and near-field communication according to claim 1, wherein the width of the longitudinal stripe pattern in step (2) is 0.5-2 mm, and the obtained nanocrystalline The magnetic permeability of the crystal magnetic conductive sheet at a frequency of 100 kHz is 3000-6000.
6. The method for preparing a nanocrystalline magnetic conductive sheet for wireless charging and near-field communication according to claim 1, wherein in step (3), the area of the central region is 1200-3600 mm ² , and the peripheral shielding The area of the region is 500 to 3000 mm ² .
7. The method for preparing a nanocrystalline magnetic conductive sheet for wireless charging and near-field communication according to claim 1, wherein in step (3), the shape of the central area is a circle or a rectangle, and the peripheral shielding The boundaries of the regions are rectangles.
8. The method for preparing a nanocrystalline magnetic conductive sheet for wireless charging and near-field communication according to claim 1, characterized in that: in step (4), the magnetic permeability of the peripheral shielding area after being crushed by secondary molding is Below 500.
9. The method for preparing a nanocrystalline magnetic conductive sheet for wireless charging and near-field communication according to claim 1, wherein the nanocrystalline magnetic conductive sheet obtained in step (4) is further laminated in multiple layers to obtain a multi-layered Nanocrystalline magnetic conductive sheet, and a heat dissipation layer is attached to the outermost layer of the multi-layer nanocrystalline magnetic conductive sheet; the heat dissipation layer is graphite, thermal conductive adhesive or a composite layer of the two.
10. A nanocrystalline magnetic conductive sheet for wireless charging and near-field communication, characterized in that: it is prepared by the method according to any one of claims 1 to 9; the central area of the nanocrystalline magnetic conductive sheet realizes the wireless charging function, The peripheral shielding area realizes the near field communication function.

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