阅读说明：本技术 一种无线充电及近场通讯用纳米晶导磁薄片及其制备方法 (Nanocrystalline magnetic conductive sheet for wireless charging and near field communication and preparation method thereof ) 是由 王湘粤 曾志超 张华� 马春博 于 2020-12-24 设计创作，主要内容包括：本发明属于磁性材料技术领域,公开了一种无线充电及近场通讯用纳米晶导磁薄片及其制备方法。对纳米晶带材进行热处理后覆保护膜,然后进行纵向辊剪处理,得到具有均匀纵向条状纹路割裂的纳米晶导磁薄片；对获得的纳米晶导磁薄片标记出中心区域和外围屏蔽区域,然后对外围屏蔽区域进行二次模压破碎以获得低于中心区域导磁薄片的磁导率,得到所述无线充电及近场通讯用纳米晶导磁薄片。本发明实现了在同一纳米晶导磁薄片上获得两种不同磁导率性能,中心区域为高磁导率区实现无线充电功能,外围屏蔽区域为低磁导率区实现近场通讯功能。采用一种磁屏蔽材料来实现无线充电和近场通讯功能最优化解决方案。(The invention belongs to the technical field of magnetic materials, and discloses a nanocrystalline magnetic-conducting sheet for wireless charging and near-field communication and a preparation method thereof. Carrying out heat treatment on the nanocrystalline strip, then coating a protective film, and then carrying out longitudinal roller shearing treatment to obtain a nanocrystalline magnetic conductive sheet with uniform longitudinal strip-shaped grain cracking; marking a central area and a peripheral shielding area on the obtained nanocrystalline magnetic conductive sheet, and then carrying out secondary die pressing and crushing on the peripheral shielding area to obtain the magnetic conductivity lower than that of the central area magnetic conductive sheet, thereby obtaining the nanocrystalline magnetic conductive sheet for wireless charging and near field communication. The invention realizes two different magnetic conductivity performances on the same nanocrystalline magnetic conductive sheet, the central area is a high magnetic conductivity area to realize a wireless charging function, and the peripheral shielding area is a low magnetic conductivity area to realize a near field communication function. A magnetic shielding material is adopted to realize the optimal solution of wireless charging and near field communication functions.)

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

(1) carrying out heat treatment on the nanocrystalline strip, and then coating a protective film on the surface of the nanocrystalline strip;

(2) carrying out longitudinal roller shearing treatment on the nanocrystalline strip coated with the protective film in the step (1) to obtain a nanocrystalline magnetic conductive sheet with uniform longitudinal strip-shaped grain fracture;

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

(4) and (4) carrying out secondary die pressing crushing on the peripheral shielding area of the nanocrystalline magnetic conductive sheet obtained in the step (3) to obtain the magnetic conductivity lower than that of the central area magnetic conductive sheet, so as to obtain the nanocrystalline magnetic conductive sheet for wireless charging and near field communication.

2. The method for preparing the nanocrystalline magnetically permeable sheet for wireless charging and near field communication according to claim 1, wherein the nanocrystalline magnetically permeable sheet comprises: the nanocrystalline strip in the step (1) is an iron-based nanocrystalline strip with the thickness of 7-28 microns.

3. The method for preparing the nanocrystalline magnetically permeable sheet for wireless charging and near field communication according to claim 1, wherein the nanocrystalline magnetically permeable sheet comprises: in the step (1), the heat treatment temperature is 500-650 ℃, and the heat treatment atmosphere is nitrogen, hydrogen or vacuum.

4. The method for preparing the nanocrystalline magnetically permeable sheet for wireless charging and near field communication according to claim 1, wherein the nanocrystalline magnetically permeable sheet comprises: the protective film material in the step (1) is any one of PET, PE, OPP, PVC, CPP or BOPP.

5. The method for preparing the nanocrystalline magnetically permeable sheet for wireless charging and near field communication according to claim 1, wherein the nanocrystalline magnetically permeable sheet comprises: the width of the longitudinal strip-shaped grain in the step (2) is 0.5-2 mm, and the magnetic conductivity of the obtained nanocrystalline magnetic conductive sheet at the frequency of 100kHz is 3000-6000.

6. The method for preparing the nanocrystalline magnetically permeable sheet for wireless charging and near field communication according to claim 1, wherein the nanocrystalline magnetically permeable sheet comprises: the area of the central area in the step (3) is 1200-3600 mm²The area of the peripheral shielding region is 500-3000 mm²。

7. The method for preparing the nanocrystalline magnetically permeable sheet for wireless charging and near field communication according to claim 1, wherein the nanocrystalline magnetically permeable sheet comprises: in the step (3), the central region is circular or rectangular, and the boundary of the peripheral shielding region is rectangular.

8. The method for preparing the nanocrystalline magnetically permeable sheet for wireless charging and near field communication according to claim 1, wherein the nanocrystalline magnetically permeable sheet comprises: and (4) the magnetic permeability of the peripheral shielding area after secondary die pressing and crushing is below 500.

9. The method for preparing the nanocrystalline magnetically permeable sheet for wireless charging and near field communication according to claim 1, wherein the nanocrystalline magnetically permeable sheet comprises: further performing multilayer lamination on the nanocrystalline magnetic conductive sheet obtained in the step (4) to obtain a multilayer nanocrystalline magnetic conductive sheet, and laminating a heat dissipation layer on the outermost layer of the multilayer nanocrystalline magnetic conductive sheet; the heat dissipation layer is graphite, heat conduction glue or a composite layer of the graphite and the heat conduction glue.

10. A nanocrystalline magnetic conduction thin slice for wireless charging and near field communication is characterized in that: prepared by the method of any one of claims 1 to 9; the central area of the nanocrystalline magnetic conductive sheet realizes a wireless charging function, and the peripheral shielding area realizes a near field communication function.

Technical Field

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

Background

In recent years, with the popularization of Wireless Power Charging (WPC) and Near Field Communication (NFC) technologies in the Field of consumer electronics, especially mobile phones, more and more mobile phone products are beginning to be labeled with these two functions, in particular, samsung electronics integrates these two functions at the mobile phone module end from Galaxy S6 mobile phone, and in addition, integrates a mobile phone payment function (MST), namely 3-Combo technology known in the market, and thereafter, flagship models (S series and Note series) of samsung mobile phones continue to use this technology. Due to the fact that the operating frequencies of a wireless charging (WPC) function and a Near Field Communication (NFC) function are different, the operating frequency of the WPC is 100-200kHz, and the operating frequency of the NFC is 13.56MHz, it is determined that the performance requirements of the two applications on the magnetic material are different. The WPC function emphasizes that the magnetic permeability of the magnetic material is higher and better, so that an electromagnetic field can be bound to the maximum extent, the charging efficiency is improved as much as possible, and the interference of the magnetic field to the outside is shielded. The NFC functionality focuses on the fact that the lower the magnetic loss of the magnetic material, the better, so that the less the attenuation during high frequency transmission of signals, the more sensitive the signal induction will be. In practical applications, the permeability and the magnetic loss of a magnetic material are a relatively contradictory set of properties, that is, the higher the permeability of the material is, the greater the magnetic loss is, and the magnetic loss of the material is reduced correspondingly. Therefore, in practical applications of wireless charging and near field communication, two different magnetic materials are often required to be selected to satisfy the two functions, and samsung electronics initially adopts an amorphous material to realize the wireless charging function and adopts a ferrite material to realize the near field communication function in a 3-Combo technology. Then, samsung electronics updated the magnetic shielding material technology, and only adopted a nanocrystalline magnetic shielding material to realize wireless charging and near field communication function simultaneously, actually because of the frequency difference of these two kinds of function application, this scheme of nanocrystalline material is only a compromise implementation scheme, namely: the method sacrifices partial wireless charging and near-field communication functions, namely in the scheme of the nanocrystalline, the wireless charging function and the near-field communication function are not optimally realized.

In the previously disclosed patents, for example, patent CN 105336465 a discloses a composite magnetic conductive sheet for wireless charging and near field communication and a preparation method thereof, and mentions a preparation method of a magnetic conductive sheet in which a powder wave-absorbing material is filled in the middle of a magnetic metal sheet to realize the combination of the two functions. Specifically, the composite magnetic conductive sheet mentioned in the patent comprises 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 synthesized by soft magnetic powder and a resin material; the intermediate layer material is at least a layer of magnetic metal sheet or a composite sheet composite body synthesized by the magnetic metal sheet, soft magnetic powder and resin material, and double-sided adhesive tapes are adhered to one surface or two surfaces of the magnetic metal sheet; and the uppermost layer material, the intermediate layer material and the lowermost layer material are subjected to hot pressing and then are formed at one time. The patent mentions that when the NFC function is carried out, enough magnetic conductivity is provided, so that enough communication distance is ensured, and the requirement of near field communication is met; meanwhile, the NFC communication function is prevented from causing interference to other processors, and accordingly, the interference of the other processors to the NFC antenna is prevented. However, the preparation method is still only a supplementary optimization of the scheme of the nanocrystalline material, and two magnetic shielding materials are adopted to meet the working requirements of two different frequency bands, namely WPC and NFC, but still cannot adopt one magnetic shielding material to realize an optimized solution of wireless charging and near field communication functions, and does not fundamentally solve how the functions of two different application frequencies realize the optimal performance in the respective application frequency bands.

Patent CN 109243755 a discloses a wide-band composite magnetic-shielding sheet and a preparation method thereof. By means of a nanocrystalline sheet and Y₂Co_17-xM_xThe sheet has a multilayer alternating structure, the cut-off frequency of the obtained magnetism isolating sheet is higher than 8GHz, the initial magnetic conductivity is higher than 20, and the magnetism isolating sheet can be compatible with wireless application from KHz to GHz. However, the patent still uses a nanocrystalline sheet and Y₂Co_17-xM_xDue to the combination of the two materials, a magnetic shielding material cannot be adopted to realize the optimal solution of the wireless charging and near field communication functions.

Other domestic patent publications show that at present, researches on magnetic materials for wireless charging and near field communication, namely amorphous magnetic materials, nanocrystalline magnetic materials and ferrite materials, do not consider the composition of two functions by using the same material. If two materials are adopted to solve the problem of the combination of the two functions, on one hand, the cost of the materials cannot be further reduced, and on the other hand, certain difficulty is brought to the subsequent assembly processing technology.

Disclosure of Invention

Aiming at the defects and shortcomings of the prior art, the invention mainly aims 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 magnetically permeable sheet prepared by the above method.

The purpose of the invention is realized by the following technical scheme:

a preparation method of a nanocrystalline magnetic conductive sheet for wireless charging and near field communication comprises the following preparation steps:

(1) carrying out heat treatment on the nanocrystalline strip, and then coating a protective film on the surface of the nanocrystalline strip;

(2) carrying out longitudinal roller shearing treatment on the nanocrystalline strip coated with the protective film in the step (1) to obtain a nanocrystalline magnetic conductive sheet with uniform longitudinal strip-shaped grain fracture;

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

(4) and (4) carrying out secondary die pressing crushing on the peripheral shielding area of the nanocrystalline magnetic conductive sheet obtained in the step (3) to obtain the magnetic conductivity lower than that of the central area magnetic conductive sheet, so as to obtain the nanocrystalline magnetic conductive sheet for wireless charging and near field communication.

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

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

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

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

Further, the area of the central area in the step (3) is 1200-3600 mm²The area of the peripheral shielding region is 500-3000 mm²。

Further, in the step (3), the central region is circular or rectangular, and the boundary of the peripheral shielding region is rectangular.

Further, the magnetic permeability of the peripheral shielding region after secondary die-pressing crushing in the step (4) is below 500 (@100 kHz).

Further, the nanocrystalline magnetic conductive sheet obtained in the step (4) is further subjected to multilayer lamination to obtain a multilayer nanocrystalline magnetic conductive sheet, and a heat dissipation layer is laminated on the outermost layer of the multilayer nanocrystalline magnetic conductive sheet.

Further, the heat dissipation layer is graphite, heat conduction glue or a composite layer of the graphite and the heat conduction glue.

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

The principle of the invention is as follows: the influence of the fragmentation degree of the nanocrystalline magnetic conductive sheet on the magnetic conductivity is utilized to divide the nanocrystalline magnetic conductive sheet into a central area and a peripheral shielding area, the central area has lower fragmentation degree and thus higher magnetic conductivity, the WPC function is realized, and the effects of improving the charging efficiency and shielding the external interference of a magnetic field are achieved; the peripheral shielding area is crushed by secondary die pressing to obtain higher fragmentation degree, so that the magnetic conductivity of the peripheral shielding area is lower than that of the magnetic conductive sheet in the central area, the peripheral shielding area is used for realizing the NFC function, and the peripheral shielding area has 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 obviously reduced, and the subsequent assembly processing technology is simplified.

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

(1) the preparation method of the invention realizes that two different magnetic conductivity performances can be obtained on the same nanocrystalline magnetic conductive sheet, wherein the central area of the nanocrystalline magnetic conductive sheet is a high magnetic conductivity area, and the wireless charging coil is arranged in the central area, thus greatly improving the efficiency of wireless charging and maximally shielding the interference of an electromagnetic field to the outside. The peripheral shielding region of the central region is a low-permeability region, so that the characteristic of low magnetic loss can be obtained, and the near-field communication coil is arranged in the shielding region, so that the induction sensitivity of the coil can be improved, and excellent communication experience can be obtained.

(2) According to the preparation method, only the longitudinal roller shearing treatment is needed to be carried out on the nanocrystalline strip, the high magnetic conductivity of the central area can be obtained, the low magnetic conductivity is obtained by carrying out secondary die pressing crushing on the peripheral shielding area, so that the magnetic loss of the magnetic shielding material is reduced, transverse shearing or multiple rolling crushing are not needed, the production efficiency is obviously improved, and the performance consistency and the stability of the nanocrystalline magnetic conductive sheet are improved.

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

Drawings

Fig. 1 is a schematic structural diagram of a nanocrystalline magnetically conductive sheet for wireless charging and near field communication in embodiment 1 of the present invention.

Fig. 2 is a schematic structural diagram of a nanocrystalline magnetically conductive sheet for wireless charging and near field communication in embodiment 2 of the present invention.

Detailed Description

The present invention will be described in further detail with reference to examples and drawings, but the present invention is not limited thereto.

Example 1

A schematic structural diagram 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 comprises a central area for realizing a wireless charging function and a peripheral shielding area for realizing a near field communication function. Wherein the central area is a circle with a diameter of 50mm, and the periphery shielding area is a rectangle with a length and a width of 70 mm. The central area is a uniform longitudinal stripe-shaped grain with the width of 1mm, and the magnetic conductivity of the central area at the frequency of 100kHz is 4500; the peripheral shielding region is a grid-shaped fragmentation with a uniform width of 1mm, and the magnetic permeability of the peripheral shielding region at the frequency of 100kHz is 450.

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

(1) carrying out heat treatment on the Fe-Cu-Nb-Si-B nanocrystalline strip (the thickness is 25 mu m) in a nitrogen atmosphere, wherein the heat treatment temperature is 560 ℃, and then coating a PET protective film on the surface of the nanocrystalline strip.

(2) And (3) carrying out longitudinal (along the length direction of the strip) roller shearing treatment on the nanocrystalline strip coated with the protective film in the step (1) to obtain the nanocrystalline magnetic conductive sheet with the uniform longitudinal strip-shaped grain fracture and the width of 1 mm.

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

(4) And (4) carrying out secondary die pressing and crushing on the peripheral shielding area of the nanocrystalline magnetic conductive sheet obtained in the step (3) into uniform grid-shaped fragmentation, and obtaining the nanocrystalline magnetic conductive sheet for wireless charging and near field communication.

The magnetic permeability of the central area of the nanocrystalline magnetic conductive sheet obtained by the method at the frequency of 100kHz is 4500; the permeability of the peripheral shield region is reduced to 450 due to the higher degree of fragmentation.

The nanocrystalline magnetic conductive sheet obtained in this example was laminated by 4 layers, and a graphite sheet heat dissipation layer was laminated on the outermost layer. And (3) carrying out wireless charging and near field communication performance testing on the obtained multilayer nanocrystalline magnetic conductive sheet:

the wireless charging performance test is a charging efficiency test, a 15W Qi standard wireless charging module is used as a transmitting terminal, the comparative example 1 is a receiving terminal module formed by combining a 4-layer nanocrystalline magnetic sheet prepared by a published patent method (201610096632.1 a non-contact flexible magnetic conductive sheet for charging and a preparation method thereof) and a receiving terminal coil, and the magnetic conductivity of the related magnetic sheet is 720. The receiving terminal modules of the above example 1 and comparative example 1 were connected to a lithium ion battery, and the voltage and current at the input terminal and the output voltage and current at the receiving terminal were measured when voltage was applied to the coil of the transmitting device. The data recording and charging efficiency calculation results of the examples are shown in table 1. As can be seen from the results in table 1, the charging efficiency of example 1 is 2.32% higher than that of comparative example 1, which shows that the charging efficiency of the nanocrystalline magnetic sheet with high magnetic permeability obtained by the process method according to the present invention is significantly improved compared with the nanocrystalline magnetic sheet with low magnetic permeability prepared by the published patent method. The high magnetic conductivity nanocrystalline magnetic sheet prepared by the method has an obvious effect on improving the wireless charging efficiency by combining the two factors.

TABLE 1

The NFC induction distance of example 1 was tested using an NFC TAG module, and comparative example 2 was a ferrite magnetic sheet for NFC produced in mass on the market and having the same thickness, and its magnetic permeability was 180, and table 2 shows the test results. From the test results, the induction distances of tag 2 and tag 4 show that the nanocrystalline scheme and the ferrite scheme of example 1 are the same, and the induction distances of tag 1 and tag 3 show that the ferrite scheme has a larger induction distance, but the nanocrystalline scheme of example 1 can basically meet the requirement of NFC performance.

TABLE 2

	tag 1	tag 2	tag 3	tag 4
					Comparative example 2	40mm	45mm	40mm	30mm
Example 1	35mm	45mm	35mm	30mm

As is apparent from the results in tables 1 and 2, the nanocrystalline magnetic conductive sheet of the present invention can simultaneously realize excellent wireless charging and near field communication functions on a nanocrystalline strip.

Example 2

A schematic structural diagram 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 comprises a central area for realizing a wireless charging function and a peripheral shielding area for realizing a near field communication function. Wherein the central area is a rectangle with the length and the width of 60mm, and the periphery shielding area boundary is a rectangle with the length and the width of 80 mm. The central area is a uniform longitudinal stripe-shaped grain crack with the width of 0.5mm, and the magnetic conductivity of the central area at the frequency of 100kHz is 3000; the peripheral shielding region is a grid-shaped fragmentation with a uniform width of 0.5mm, and the magnetic permeability of the peripheral shielding region at the frequency of 100kHz is 300.

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

(1) carrying out heat treatment on the Fe-Cu-Nb-Si-B nanocrystalline strip (the thickness is 18 mu m) in a nitrogen atmosphere at the heat treatment temperature of 600 ℃, and then coating a PVC protective film on the surface of the nanocrystalline strip.

(2) And (3) carrying out longitudinal roller shearing treatment on the nanocrystalline strip coated with the protective film in the step (1) to obtain the nanocrystalline magnetic-conducting sheet with the width of 0.5mm and uniform longitudinal strip-shaped grain cracking.

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

(4) And (4) carrying out secondary die pressing and crushing on the peripheral shielding area of the nanocrystalline magnetic conductive sheet obtained in the step (3) into uniform grid-shaped fragmentation, and obtaining the nanocrystalline magnetic conductive sheet for wireless charging and near field communication.

The magnetic permeability of the central area of the nanocrystalline magnetic conductive sheet obtained by the method is 3000 at the frequency of 100 kHz; the permeability of the peripheral shield region is reduced to 300 due to the higher degree of fragmentation.

The nanocrystalline magnetic conductive sheet obtained in this example was laminated by 4 layers, and a graphite sheet heat dissipation layer was laminated on the outermost layer. And (3) carrying out wireless charging and near field communication performance testing on the obtained multilayer nanocrystalline magnetic conductive sheet:

the wireless charging performance test is a charging efficiency test, a 15W Qi standard wireless charging module is used as a transmitting terminal, the comparative example 1 is a receiving terminal module formed by combining a 4-layer nanocrystalline magnetic sheet prepared by a published patent method (201610096632.1 a non-contact flexible magnetic conductive sheet for charging and a preparation method thereof) and a receiving terminal coil, and the magnetic conductivity of the related magnetic sheet is 720. The receiving terminal modules of the above example 2 and comparative example 1 were connected to a lithium ion battery, and the voltage and current at the input terminal and the output voltage and current at the receiving terminal were measured when voltage was applied to the coil of the transmitting device. The data records and charging efficiency calculations for the examples are shown in table 3. As can be seen from the results in table 3, the charging efficiency of example 2 is 2.52% higher than that of comparative example 1, which shows that the charging efficiency of the nanocrystalline magnetic sheet with high magnetic permeability obtained by the process method according to the present invention is significantly improved compared with the nanocrystalline magnetic sheet with low magnetic permeability prepared by the published patent method. The high magnetic conductivity nanocrystalline magnetic sheet prepared by the method has an obvious effect on improving the wireless charging efficiency by combining the two factors.

TABLE 3

The NFC induction distance of example 2 was tested using an NFC TAG module, and comparative example 2 was a ferrite magnetic sheet for NFC produced in mass on the market and having the same thickness, and its magnetic permeability was 180, and table 4 shows the test results. From the test results, the induction distances of tag 2 and tag 4 show that the nanocrystalline scheme and the ferrite scheme of example 1 are the same, and the induction distances of tag 1 and tag 3 show that the ferrite scheme has a larger induction distance, but the nanocrystalline scheme of example 2 can also basically meet the requirement of NFC performance.

TABLE 4

	tag 1	tag 2	tag 3	tag 4
					Comparative example 2	40mm	45mm	40mm	30mm
Example 2	35mm	45mm	33mm	30mm

As is apparent from the results in tables 3 and 4, the nanocrystalline magnetic conductive sheet of the present invention can simultaneously realize excellent wireless charging and near field communication functions on a nanocrystalline strip.

Example 3

The nanocrystalline magnetic conductive sheet for wireless charging and near field communication in the embodiment comprises a central area for realizing a wireless charging function and a peripheral shielding area for realizing a near field communication function. Wherein the central area is a circle with the diameter of 40mm, and the periphery shielding area boundary is a rectangle with the length and the width of 50 mm. The central area is a uniform longitudinal stripe-shaped grain crack with the width of 2mm, and the magnetic conductivity of the central area at the frequency of 100kHz is 6000; the peripheral shielding region is a grid-shaped fragmentation with a uniform width of 2mm, and the magnetic permeability of the peripheral shielding region at the frequency of 100kHz is 500.

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

(1) carrying out heat treatment on the Fe-Cu-Nb-Si-B nanocrystalline strip (the thickness is 14 microns) in a nitrogen atmosphere, wherein the heat treatment temperature is 630 ℃, and then coating a BOPP protective film on the surface of the nanocrystalline strip.

(2) And (3) carrying out longitudinal roller shearing treatment on the nanocrystalline strip coated with the protective film in the step (1) to obtain the nanocrystalline magnetic conductive sheet with 2mm width and uniform longitudinal strip-shaped grain fracture.

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

(4) And (4) carrying out secondary die pressing and crushing on the peripheral shielding area of the nanocrystalline magnetic conductive sheet obtained in the step (3) into uniform grid-shaped fragmentation, and obtaining the nanocrystalline magnetic conductive sheet for wireless charging and near field communication.

The magnetic permeability of the central area of the nanocrystalline magnetic conductive sheet obtained by the method is 6000 at the frequency of 100 kHz; the permeability of the peripheral shield region is reduced to 500 due to the higher degree of fragmentation.

The nanocrystalline magnetic conductive sheet obtained in this embodiment is laminated by 5 layers, and a heat conductive adhesive heat dissipation layer is laminated on the outermost layer. And (3) carrying out wireless charging and near field communication performance testing on the obtained multilayer nanocrystalline magnetic conductive sheet:

the wireless charging performance test is a charging efficiency test, a 15W Qi standard wireless charging module is used as a transmitting terminal, the comparative example 3 is a receiving terminal module formed by combining a 5-layer nanocrystalline magnetic sheet prepared by a published patent method (201610096632.1 a non-contact flexible magnetic conductive sheet for charging and a preparation method thereof) and a receiving terminal coil, and the magnetic conductivity of the related magnetic sheet is 750. The receiving terminal modules of the above example 3 and comparative example 3 were connected to a lithium ion battery, and the voltage and current at the input terminal and the output voltage and current at the receiving terminal were measured when voltage was applied to the coil of the transmitting device. The data records and charging efficiency calculations for the examples are shown in table 5. As can be seen from the results in table 5, the charging efficiency of example 3 is 1.82% higher than that of comparative example 3, which shows that the charging efficiency of the nanocrystalline magnetic sheet with high magnetic permeability obtained by the process method according to the present invention is significantly improved compared with the nanocrystalline magnetic sheet with low magnetic permeability prepared by the published patent method. The high magnetic conductivity nanocrystalline magnetic sheet prepared by the method has an obvious effect on improving the wireless charging efficiency by combining the two factors.

TABLE 5

The NFC induction distance of example 3 was tested using the NFC TAG module, and comparative example 4 was a ferrite magnetic sheet for NFC produced in mass on the market and having the same thickness, and its magnetic permeability was 150, and 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, the sensing distance of tag 3 shows that the ferrite scheme sensing distance is slightly larger, and the NFC performance of the nanocrystalline scheme of example 3 is almost close to the ferrite performance.

TABLE 6

	tag 1	tag 2	tag 3	tag 4
					Comparative example 4	40mm	45mm	40mm	30mm
Example 3	40mm	45mm	38mm	30mm

As is apparent from the results in tables 5 and 6, the nanocrystalline magnetic conductive sheet of the present invention can simultaneously realize excellent wireless charging and near field communication functions on a nanocrystalline strip.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.