A nanocrystalline alloy magnetic shielding device with ultra-low magnetic noise and its fabrication method

Abstract

This disclosure relates to the field of low magnetic noise magnetic shielding technology, and discloses a nanocrystalline alloy magnetic shielding device with ultra-low magnetic noise and its preparation method. The device includes: a nanocrystalline alloy strip obtained by annealing and crystallizing a finemet-type amorphous alloy strip; a non-magnetic protective film disposed on the nanocrystalline alloy strip, the protective film being bonded to the nanocrystalline alloy strip by an insulating adhesive; a single-layer magnetic shielding sheet formed by splicing and die-cutting multiple nanocrystalline alloy strips, with an overlapping area at the splicing points of adjacent nanocrystalline alloy strips; a multi-layer magnetic shielding structure formed by stacking or winding the single-layer magnetic shielding sheet; and a non-magnetic support frame for supporting and fixing the multi-layer magnetic shielding structure. By using a finemet-type nanocrystalline alloy as the core magnetic shielding material and bonding it with a non-magnetic protective film, a unique structure is achieved that balances ultra-low inherent magnetic noise and excellent machinability in the magnetic shielding device.

Description

Technical Field

[0001] This invention relates to the field of low magnetic noise magnetic shielding technology, specifically to a nanocrystalline alloy magnetic shielding device with ultra-low magnetic noise and its preparation method. Background Technology

[0002] The rapid development in fields such as quantum precision measurement, biological weak magnetic imaging, and fundamental physics experiments has brought the detection sensitivity of extremely weak magnetic field signals to the sub-fT level. Under this extreme sensitivity, the inherent magnetic noise of the magnetic shielding system itself has become the core bottleneck restricting further improvement in measurement accuracy. Constructing an ultra-low magnetic noise shielding environment is a prerequisite for achieving high-precision measurement of extremely weak magnetic field signals.

[0003] In related technologies, mainstream magnetic shielding systems mostly use soft magnetic materials with high permeability, such as permalloy. Although these materials have good static shielding effectiveness, their high conductivity easily generates significant eddy current magnetic noise, which severely interferes with the accurate extraction of extremely weak magnetic field signals. To reduce magnetic noise, the industry has attempted to introduce ferrite devices into the inner layer of permalloy systems. While this has yielded some low-noise advantages, the inherent brittleness of ferrite materials and the complexity of sintering processes present significant challenges in fabricating large-size, lightweight, and complex-shaped shielding devices, resulting in high costs and limited applications.

[0004] Therefore, how to overcome the limitations of existing material systems and develop a new type of magnetic shielding device that combines ultra-low inherent magnetic noise, excellent processing characteristics and lightweight advantages to meet the stringent requirements of cutting-edge technologies for extremely weak magnetic field measurement environments has become a key technical challenge that urgently needs to be overcome in this field. Summary of the Invention

[0005] In view of this, the present invention provides a nanocrystalline alloy magnetic shielding device with ultra-low magnetic noise and a method for its preparation, so as to solve the technical problem that existing magnetic shielding materials are difficult to balance with the requirements of ultra-low inherent magnetic noise, easy processing and lightweight in high-sensitivity extremely weak magnetic field measurement applications.

[0006] This disclosure provides a nanocrystalline alloy magnetic shielding device with ultra-low magnetic noise, comprising:

[0007] Nanocrystalline alloy strip obtained by annealing and crystallization treatment of Finemet-type amorphous alloy strip;

[0008] A non-magnetic protective film is disposed on at least one surface of the nanocrystalline alloy strip, and the non-magnetic protective film is bonded to the nanocrystalline alloy strip by an insulating adhesive.

[0009] A single-layer magnetic shielding sheet is formed by splicing and die-cutting multiple nanocrystalline alloy strips. During the splicing process, an overlapping area is set at the splicing point of adjacent nanocrystalline alloy strips.

[0010] A multi-layer magnetic shielding structure formed by stacking or winding at least one single-layer magnetic shielding sheet; and a non-magnetic support frame for supporting and fixing the multi-layer magnetic shielding structure.

[0011] This disclosure also provides a method for preparing a nanocrystalline alloy magnetic shielding device, comprising:

[0012] We offer fine-mesh amorphous alloy strips.

[0013] Finemet-type amorphous alloy strips were subjected to annealing and crystallization treatment to obtain nanocrystalline alloy strips.

[0014] Multiple nanocrystalline alloy strips are spliced ​​together, and an overlapping area is set at the splicing point of adjacent nanocrystalline alloy strips to form a single-layer magnetic shielding sheet.

[0015] At least one single-layer magnetic shielding sheet is stacked or wound to form a multi-layer magnetic shielding structure, and then fixed to a non-magnetic support frame to assemble a magnetic shielding device.

[0016] This disclosure also provides a magnetic shielding system, including the aforementioned nanocrystalline alloy magnetic shielding device with ultra-low magnetic noise.

[0017] The present disclosure discloses a nanocrystalline alloy magnetic shielding device and its fabrication method with ultra-low magnetic noise, which utilizes a finemet-type nanocrystalline alloy as the core magnetic shielding material and a unique structure formed by bonding a non-magnetic protective film to form a nanocrystalline alloy strip. This solves the inherent contradiction between the high eddy current magnetic noise of permalloy and the difficulty in processing ferrite, achieving a balance between ultra-low inherent magnetic noise and excellent machinability of the magnetic shielding device, providing an ideal environment for measuring extremely weak magnetic field signals. By using multiple nanocrystalline alloy strips with overlapping areas for splicing and by stacking or winding single-layer magnetic shielding sheets to form a multi-layer structure, magnetic flux leakage at the joints is effectively suppressed, and the shielding effectiveness is controllably adjustable. This results in a large-size magnetic shielding device with excellent magnetic continuity, structural stability, and performance scalability.

[0018] Furthermore, by supporting and shaping the entire multi-layer magnetic shielding structure with a non-magnetic support skeleton, the device is endowed with a stable mechanical form and flexible structural adaptability, enabling it to be fabricated into various geometric configurations. This achieves a balance between lightweight, high shielding performance, and universality of application scenarios, significantly expanding the application prospects of ultra-low magnetic noise shielding technology in precision instruments and cutting-edge scientific research fields such as atomic magnetometers and biological weak magnetic signal measurement. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the specific embodiments or related technologies of this disclosure, the accompanying drawings used in the description of the specific embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is an exploded view of the overall structure of a nanocrystalline alloy magnetic shielding device with ultra-low magnetic noise according to an embodiment of this disclosure.

[0021] Figure 2 This is a schematic diagram of the planar structure of a single-layer magnetic shielding sheet of a nanocrystalline alloy magnetic shielding device with ultra-low magnetic noise according to an embodiment of this disclosure.

[0022] Figure 3 This is a schematic diagram of the layered structure at the overlapping region of a nanocrystalline alloy magnetic shielding device with ultra-low magnetic noise according to an embodiment of this disclosure.

[0023] Figure 4 This is a schematic diagram showing the relationship between complex permeability and frequency of a nanocrystalline alloy magnetic shielding device with ultra-low magnetic noise according to an embodiment of this disclosure.

[0024] Figure 5 This is a schematic diagram of the annealing process of a nanocrystalline alloy magnetic shielding device with ultra-low magnetic noise according to an embodiment of this disclosure.

[0025] Figure 6 This is a schematic diagram comparing the magnetic noise of single-layer and three-layer cylindrical nanocrystalline alloy magnetic shielding devices with ultra-low magnetic noise, according to an embodiment of this disclosure, with that of a permalloy system.

[0026] Figure 7 This is a schematic diagram comparing the magnetic noise of a five-layer cylindrical nanocrystalline alloy magnetic shielding device with ultra-low magnetic noise, according to an embodiment of this disclosure, with that of a permalloy system.

[0027] Figure 8 This is a schematic diagram of a cylindrical nanocrystalline alloy magnetic shielding device with ultra-low magnetic noise, according to an embodiment of the present disclosure.

[0028] Figure 9 This is a schematic diagram of a square nanocrystalline alloy magnetic shielding device with ultra-low magnetic noise, according to an embodiment of the present disclosure.

[0029] Figure 10 This is a schematic flowchart of the preparation method of the nanocrystalline alloy magnetic shielding device provided in the embodiments of this disclosure;

[0030] Figure 11 This is a schematic diagram comparing the magnetic noise of a square nanocrystalline alloy magnetic shielding device with ultra-low magnetic noise and a permalloy system, according to an embodiment of this disclosure. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0032] The rapid development of cutting-edge technologies such as quantum precision measurement, biological weak magnetic imaging, dark matter detection, and inertial navigation has brought the detection sensitivity of extremely weak magnetic field signals to the sub-fT level. Under this extreme sensitivity, the inherent magnetic noise of the magnetic shielding system itself has become the core bottleneck restricting further improvement in measurement accuracy. Constructing an ultra-low magnetic noise silent environment is a prerequisite for achieving high-precision measurement of extremely weak magnetic field signals.

[0033] In the first related technologies, commercially available high-performance magnetic shielding systems commonly employ permalloy and other soft magnetic materials with high permeability. Through multi-layered permalloy shell structures, their high permeability provides effective shielding against static and low-frequency magnetic fields. However, permalloy in the first related technologies exhibits significant eddy current losses due to its high conductivity, leading to magnetic noise, typically in the tens of degrees. The magnitude of the interference severely hinders and limits the accurate extraction of extremely weak magnetic field signals by ultra-high sensitivity detectors such as atomic magnetometers.

[0034] Furthermore, the second related technology involves introducing ferrite material into the innermost layer of the permalloy magnetic shielding system. As a soft magnetic material with high resistivity, ferrite can effectively suppress eddy currents, thus possessing the inherent advantage of low magnetic noise and showing application potential in extremely weak magnetic field measurements.

[0035] However, the following problems exist in the second related technology:

[0036] 1. Ferrite materials are inherently brittle and have complex sintering processes, which leads to significant technical challenges and extremely high manufacturing costs when fabricating large-size, lightweight, and complex geometric shielding devices.

[0037] 2. Due to limitations in processing technology, ferrite devices are usually bulky and have a simple structure, making it difficult to meet the urgent needs of modern precision instruments for flexible design, integration, and lightweight magnetic shielding components.

[0038] To address the aforementioned problems, various embodiments of this disclosure provide a nanocrystalline alloy magnetic shielding device with ultra-low magnetic noise, comprising: a nanocrystalline alloy strip obtained by annealing and crystallizing a finemet-type amorphous alloy strip; a non-magnetic protective film disposed on at least one surface of the nanocrystalline alloy strip, the non-magnetic protective film being bonded to the nanocrystalline alloy strip by an insulating adhesive; a single-layer magnetic shielding sheet of a specific size and shape formed by splicing and die-cutting multiple nanocrystalline alloy strips, wherein an overlapping area is provided at the splicing point of adjacent nanocrystalline alloy strips during the splicing process; a multi-layer magnetic shielding structure formed by stacking or winding at least one single-layer magnetic shielding sheet; and a non-magnetic support frame for supporting and fixing the multi-layer magnetic shielding structure.

[0039] Please refer to Figures 1 to 3 , Figure 1 This is an exploded view of the overall structure of a nanocrystalline alloy magnetic shielding device with ultra-low magnetic noise according to an embodiment of this disclosure. Figure 2 This is a schematic diagram of the planar structure of a single-layer magnetic shielding sheet of a nanocrystalline alloy magnetic shielding device with ultra-low magnetic noise according to an embodiment of this disclosure. Figure 3 This is a schematic diagram of the layered structure at the overlapping region of a nanocrystalline alloy magnetic shielding device with ultra-low magnetic noise according to an embodiment of this disclosure. Figure 2 The structure shown is Figure 1 An enlarged view of the position indicated by the dashed circle A. Figure 3 The structure shown is Figure 2 Enlarged view of the position indicated by the dashed circle B.

[0040] like Figure 1 As shown, its overall structure includes: a non-magnetic support frame 101, a multi-layer magnetic shielding structure 102 fixed on the non-magnetic support frame 101, and a single-layer magnetic shielding sheet 103 constituting the multi-layer magnetic shielding structure 102.

[0041] In this embodiment, the non-magnetic support frame 101 serves as the mechanical foundation of the entire device and can be used for support and shaping. It can be designed into a cylindrical, square, or other required geometric shape according to the actual application scenario.

[0042] The multilayer magnetic shielding structure 102 uses one or more ( Figure 1 (The example in the text shows multiple) Single-layer magnetic shielding sheets 103 are stacked or wound together and fixed to the aforementioned non-magnetic support frame 101. By increasing the number of single-layer magnetic shielding sheets 103, the overall magnetic shielding performance of the device can be linearly improved.

[0043] Preferably, the planar skeleton can be used to fix a single layer of magnetic shielding sheet 103 by stacking, such as a square non-magnetic support skeleton 101; the curved skeleton can be used to fix a single layer of magnetic shielding sheet 103 by winding, such as a cylindrical non-magnetic support skeleton 101.

[0044] Please refer to further information. Figure 2 It demonstrates the configuration of a single-layer magnetic shielding sheet 103.

[0045] The single-layer magnetic shielding sheet 103 is composed of multiple nanocrystalline alloy strips 104 spliced ​​together in a plane.

[0046] Preferably, in order to ensure the continuity of the magnetic path and suppress magnetic leakage, an overlap area 105 of a specific width is provided at the splice of adjacent nanocrystalline alloy strips 104.

[0047] Insulating adhesive layers 107 can be provided on the upper and lower surfaces of multiple nanocrystalline alloy strips 104.

[0048] An insulating adhesive layer 107 is used to firmly adhere the non-magnetic protective film 106 to the functional layer;

[0049] Among them, the non-magnetic protective film 106, as the outermost protective layer of the single-layer magnetic shielding sheet 103, can be used to provide mechanical protection, enhance toughness and achieve electrical insulation.

[0050] The structure shown at position 105 of the overlapping region can be referenced. Figure 3 As shown, adjacent nanocrystalline alloy strips 104 can be bonded together using an insulating adhesive layer 107. Preferably, the width of the overlapping area 105 between adjacent nanocrystalline alloy strips 104 can be kept consistent.

[0051] Furthermore, the nanocrystalline alloy strip 104, as the core functional layer in the single-layer magnetic shielding sheet 103, is obtained by annealing and crystallizing the finemet-type amorphous alloy strip and is responsible for providing magnetic shielding functions with high magnetic permeability and ultra-low magnetic noise.

[0052] Finemet-type amorphous alloy strips refer to a class of soft magnetic amorphous alloys with iron (Fe) as the main element and containing silicon (Si), boron (B), and small amounts of copper (Cu), niobium (Nb), etc. Their typical characteristic is that they form an amorphous structure through rapid solidification technology, and after appropriate annealing, they can precipitate uniformly distributed nanocrystals.

[0053] It is understandable that the Finemet-type amorphous alloy strips mentioned here are not limited to specific alloys commercially known as "Finemet," but can encompass all iron-based soft magnetic amorphous alloys with similar compositional systems and capable of obtaining nanocrystalline structures through crystallization treatment.

[0054] Preferably, the Finemet-type amorphous alloy strip in this embodiment can be prepared by a single-roller spinning method, and the width can be [missing information]. The thickness can be .

[0055] Annealing crystallization treatment refers to the heat treatment process in which the aforementioned Finemet-type amorphous alloy strip is heated to its crystallization temperature range under a certain protective atmosphere and held at that temperature, causing its internal structure to transform from amorphous to a multiphase structure containing nanocrystals. Annealing crystallization treatment can include one-step, two-step, or multi-step annealing procedures. Its core lies in controlling the heating and cooling rates, temperature range, and holding time to obtain the desired nanocrystalline microstructure and fully release internal stress.

[0056] Non-magnetic protective film 106 can refer to a flexible thin film material that does not exhibit ferromagnetism or subferromagnetism in its working magnetic field environment. Its function is to provide mechanical protection, enhance toughness, and achieve interlayer insulation for brittle nanocrystalline ribbons.

[0057] Preferably, the material of the non-magnetic protective film 106 may include, but is not limited to: polyethylene terephthalate (PET), polyimide, polyethylene naphthalate (PEN), etc.

[0058] The insulating adhesive used in the insulating adhesive layer 107 can be any adhesive with high resistivity used to firmly bond the non-magnetic protective film 106 to the surface of the nanocrystalline alloy strip 104. Its material selection may include, but is not limited to, epoxy resin, acrylic adhesive, silicone adhesive, or polyurethane adhesive.

[0059] The present disclosure discloses a nanocrystalline alloy magnetic shielding device and its fabrication method with ultra-low magnetic noise, which utilizes a fine-met type nanocrystalline alloy as the core magnetic shielding material and incorporates a unique structure with a non-magnetic protective film. This overcomes the inherent contradiction between the high eddy current magnetic noise of permalloy and the difficulty in processing ferrites, achieving a balance between ultra-low inherent magnetic noise and excellent machinability, thus providing an ideal environment for measuring extremely weak magnetic fields. Furthermore, the method of splicing multiple nanocrystalline alloy strips with overlapping areas and layering or winding single-layer magnetic shielding sheets to form a multi-layer structure effectively suppresses magnetic flux leakage at the seams and enables controllable adjustment of shielding effectiveness. This results in a large-size magnetic shielding device with excellent magnetic continuity, structural stability, and performance scalability. By supporting and shaping the entire multi-layer magnetic shielding structure with a non-magnetic support skeleton, the device is given a stable mechanical form and flexible structural adaptability, which enables it to be fabricated into a variety of geometric configurations. This achieves a balance between lightweighting and universality of application scenarios, and significantly expands the application prospects of ultra-low magnetic noise shielding technology in precision instruments and cutting-edge scientific research fields such as atomic magnetometers and biological weak magnetic signal measurement.

[0060] In one possible implementation of the above embodiments, the microstructure of the nanocrystalline alloy strip 104 is predominantly single-phase. Nanocrystalline phase, and the grain size of the nanocrystals is .

[0061] In this embodiment, through the aforementioned specific annealing and crystallization treatment, the Finemet-type amorphous alloy strip has been transformed into a nanocrystalline alloy strip 104 with a specific microstructure.

[0062] This microstructure is mainly composed of a single... It is composed of nanocrystalline phases.

[0063] The average grain size of the nanocrystalline phase can be controlled within between.

[0064] For example, in one specific embodiment, the average diameter of the nanocrystals obtained by the above-described annealing and crystallization treatment is approximately .

[0065] Experiments show that the nanocrystalline alloy strip 104 with this microstructure... Under a weak magnetic field, The loss factor can be as low as [missing information] within the frequency range. The magnitude is much lower than that of traditional permalloy and ferrite materials, thus providing an extremely low intrinsic magnetic noise substrate for magnetic shielding devices.

[0066] For a concrete example, please refer to Figure 4 , Figure 4This is a schematic diagram illustrating the relationship between complex permeability and frequency for a nanocrystalline alloy magnetic shielding device with ultra-low magnetic noise according to an embodiment of this disclosure. Figure 4 As shown:

[0067] Figure 4 The real part of the relative complex permeability of nanocrystalline alloy strip 104 obtained by annealing and crystallization is shown under different external magnetic field conditions. With the imaginary part The curve shows the effect of frequency. It can be clearly seen that the nanocrystalline alloy strip 104 exhibits high performance within the indicated frequency range, especially... Under typical weak magnetic field conditions, it exhibits extremely high performance. Value and extremely low Value. Loss factor calculated based on this data. exist Only within the frequency range This extremely low loss factor value is far lower than the typical value of traditional permalloy and ferrite materials, directly confirming that the nanocrystalline alloy strip 104 has extremely low inherent magnetization noise, providing key material science assurance for the core magnetic shielding function.

[0068] The nanocrystalline alloy magnetic shielding device and its preparation method with ultra-low magnetic noise described in the above embodiments of this disclosure define the microstructure of the nanocrystalline alloy to the grain size. single phase The nanocrystalline phase significantly suppresses the magnetocrystalline anisotropy of the material. The aforementioned uniform and fine nanocrystalline structure allows the material to possess extremely high initial permeability under weak fields, while simultaneously reducing the loss factor to a minimum. The magnitude is far lower than that of traditional permalloy and ferrite, providing devices with high shielding effectiveness and a low-noise substrate.

[0069] In one possible implementation of the above embodiments, the annealing crystallization process is a three-step annealing process performed under an inert gas or vacuum atmosphere, including:

[0070] First annealing stage: In Lower Annealing minute;

[0071] Second annealing stage: In Lower Annealing minute;

[0072] Third annealing stage: In Lower Annealing minute.

[0073] In this embodiment, the three-step annealing process is a key process guarantee for achieving excellent microstructure and magnetic properties in the nanocrystalline alloy strip 104.

[0074] Please refer to Figure 5 , Figure 5 This is a schematic diagram of the annealing process of a nanocrystalline alloy magnetic shielding device with ultra-low magnetic noise according to an embodiment of this disclosure, as shown below. Figure 5 As shown, it displays the temperature and time curves of the three-step annealing process.

[0075] The first annealing stage is carried out at a relatively low temperature. Its main purpose is to fully eliminate the macroscopic and microscopic internal stresses accumulated in the amorphous alloy strip by the rapid solidification and winding process and to form Cu clusters, providing nucleation sites for the subsequent precipitation of nanocrystals.

[0076] Preferably, the first annealing stage can be set at... Lower Annealing minute.

[0077] The second annealing stage can be carried out near the initial crystallization temperature. This stage is the initial nucleation and controlled growth stage of nanocrystals. Precisely controlling the temperature and time of this stage can ensure... The crystal nuclei are formed uniformly at a high density.

[0078] Preferably, the second annealing stage can be set in... Lower Annealing minute.

[0079] The third annealing stage can be carried out near the peak crystallization temperature. This stage aims to further stabilize and moderately grow the formed nanocrystals, while making the grain size distribution more uniform. Finally, the temperature is lowered to room temperature to obtain grains with a size that is within the range specified in the original text. Single-phase within the range and with a high volume fraction Nanocrystalline microstructure.

[0080] Preferably, the third annealing stage can be set at... Lower Annealing minute.

[0081] Furthermore, the entire annealing process can be carried out in an inert gas or vacuum atmosphere, which can effectively prevent oxidation of the strip surface and ensure the uniformity and reliability of the final product performance.

[0082] The nanocrystalline alloy magnetic shielding device and its preparation method with ultra-low magnetic noise described in the above embodiments of this disclosure utilize a three-step annealing method to obtain an ideal single-phase material with uniform grain size, high density, and fully eliminated internal stress. The nanocrystalline microstructure provides a repeatable and controllable precise process path. By precisely controlling the thermal process in stages, the two key properties of high magnetic permeability and extremely low magnetic loss are synergistically optimized in the same material, achieving synergistic optimization of magnetic properties. Compared with conventional single-step annealing, this three-step method decomposes the complex crystallization process into more controllable independent steps, reducing sensitivity to process fluctuations. This significantly improves the uniformity, stability, and yield of the magnetic properties of nanocrystalline alloy strips, meeting the needs of industrial production.

[0083] In one possible implementation of the above embodiments, the non-magnetic protective film 106 is a polyethylene terephthalate film with a thickness of [missing information]. The thickness of the insulating adhesive is .

[0084] In this embodiment, the non-magnetic protective film 106 is made of PET film because this material has excellent insulation, mechanical strength, flexibility and chemical stability, and is inexpensive and easy to commercialize.

[0085] Furthermore, the thickness of the PET film is limited to Within the range, it can be the optimal result after full consideration.

[0086] Here, when the thickness is less than At times, the mechanical protection and durability of the film may be insufficient, making it easily scratched or punctured during subsequent splicing, lamination, and other processing; while if the thickness is greater than If this is done, it will unnecessarily increase the overall stiffness of the nanocrystalline alloy strip 104, which is not conducive to its winding and bonding on irregular curved surfaces, affecting the molding process, and will also increase the non-functional volume and weight of the device.

[0087] Furthermore, the insulating adhesive layer 107 can achieve a firm, uniform, and durable bond between the PET film and the nanocrystalline alloy strip 104.

[0088] The thickness of the insulating adhesive layer 107 is controlled within... This is also the preferred result that achieves the best balance between bond strength, insulation reliability and process feasibility.

[0089] Here, if the thickness is less than Insufficient adhesive application may result in unbonded areas, affecting the adhesion of the protective film and posing a risk of interlayer short circuits; a thickness greater than [a certain value] may also lead to insufficient adhesive application, creating unbonded areas, affecting the adhesion of the protective film, and posing a risk of interlayer short circuits. This would result in an excessively thick adhesive layer, which could not only introduce too much volatile organic matter, affecting long-term stability, but also affect the flatness of the nanocrystalline alloy strip 104 after curing due to internal stress or flowability issues in the adhesive layer.

[0090] Therefore, by limiting the material and precise thickness parameters of the PET film and the insulating adhesive, this preferred solution ensures that the nanocrystalline alloy strip 104 possesses excellent magnetic properties while also achieving ideal mechanical toughness, processing tolerance, and long-term reliability.

[0091] The nanocrystalline alloy magnetic shielding device and its preparation method with ultra-low magnetic noise, as disclosed in the above embodiments, utilize PET films of a specific thickness range to provide sufficient mechanical protection for brittle nanocrystalline ribbons while maximizing the maintenance of the nanocrystalline alloy ribbons' flexibility and lightweight characteristics. This allows for smooth subsequent splicing, winding, and other forming processes, thereby achieving an optimized balance between functional materials and structural protection. By precisely controlling the thickness of the insulating adhesive layer... This ensures a strong, uniform, and defect-free bond between the nanocrystalline alloy strip and the protective film, effectively preventing interlayer delamination and electrical breakdown risks, and providing a guarantee for the long-term stable operation of the device under complex conditions. The specific material and parameter limitations mentioned above make the fabrication process of the nanocrystalline alloy strip easier to control, significantly improving the consistency of product performance.

[0092] In one possible implementation of the above embodiment, the width of the overlapping area 105 is .

[0093] In this embodiment, the width of the overlapping region 105 is related to the magnetic shielding performance of the device, and the width is... It can be the optimal result of balancing magnetic properties and structural design.

[0094] Specifically, when the width of the overlapping area is less than When the magnetic path connection area between adjacent nanocrystalline alloy strips 104 is insufficient, it cannot effectively guide magnetic lines of force through the joint, which will lead to significant magnetic flux leakage, forming a weak link in the magnetic shielding effectiveness and seriously affecting the overall shielding effect.

[0095] When the width of the overlapping area is greater than While this ensures magnetic connectivity, it can lead to excessive material overlap in the region, resulting in a significant increase in local thickness, material waste, and increased costs. This unnecessary thickening may affect the flatness of subsequent lamination or winding processes and introduce unnecessary stress into the device.

[0096] Preferably, in the specific implementation process, the width of the overlapping area 105 is set to This width provides a sufficiently continuous low magnetic resistance path for the magnetic flux, effectively suppressing magnetic leakage, while maintaining the overall flatness and thickness uniformity of the single-layer magnetic shielding sheet 103, ensuring the construction quality of the subsequent multi-layer magnetic shielding structure 102.

[0097] Therefore, the width of the overlapping area is limited to Within this range, it is an optimized choice from an engineering practice perspective. It takes ensuring magnetic continuity as its core objective while also considering material utilization, process feasibility, and manufacturing cost.

[0098] The nanocrystalline alloy magnetic shielding device and its preparation method with ultra-low magnetic noise, as described in the above embodiments of this disclosure, are achieved by setting... The wide overlap region provides ample magnetic pathway connections between adjacent nanocrystalline alloy strips, effectively eliminating magnetic flux leakage caused by splicing gaps and ensuring the high uniformity of the shielding effectiveness of the magnetic shielding device. This width range, while ensuring magnetic performance, avoids material waste, local thickening, and increased costs caused by excessive overlap, achieving the optimal balance between magnetic shielding performance and structural economy.

[0099] In a preferred embodiment of the above embodiments, the number of single-layer magnetic shielding sheets 103 in the multilayer magnetic shielding structure 102 can be 3 or 5. This number of layers can be determined based on extensive experimental verification, and is a preferred option that can optimally balance shielding performance, material cost, and device weight.

[0100] Please refer to Figure 6 and Figure 7 , Figure 6 This is a schematic diagram comparing the magnetic noise of single-layer and three-layer cylindrical nanocrystalline alloy magnetic shielding devices with ultra-low magnetic noise, according to an embodiment of this disclosure, with that of a permalloy system. Figure 7 This is a schematic diagram comparing the magnetic noise of a five-layer cylindrical nanocrystalline alloy magnetic shielding device with ultra-low magnetic noise, according to an embodiment of this disclosure, with that of a permalloy system.

[0101] like Figure 6 As shown, Figure 6 This diagram illustrates a comparison of magnetic noise test results between a single-layer cylindrical nanocrystalline alloy magnetic shielding device (circle), a three-layer cylindrical nanocrystalline alloy magnetic shielding device (triangle), and a permalloy magnetic shielding system (square) from related technologies serving as a reference. The horizontal axis represents frequency, and the vertical axis represents magnetic noise.

[0102] As shown by the curve, the permalloy magnetic shielding system in The average magnetic noise within the range is approximately This represents the typical noise floor of related technologies without the devices described in this disclosure, forming the baseline for this performance comparison. The single-layer cylindrical nanocrystalline alloy magnetic shielding device... The average magnetic noise within the range is reduced to Compared with the permalloy magnetic shielding system, the magnetic noise is reduced by more than 50%, indicating that even a single-layer cylindrical nanocrystalline alloy magnetic shielding device in the embodiments of this disclosure can have a significant suppression effect on the magnetic noise generated by permalloy.

[0103] The three-layer cylindrical nanocrystalline alloy magnetic shielding device is internal The average magnetic noise within the range is further reduced to This indicates that increasing the thickness of the cylindrical nanocrystalline alloy magnetic shielding device can further enhance the suppression effect on magnetic noise generated by permalloy.

[0104] The magnetic noise test results of the five-layer cylindrical nanocrystalline alloy magnetic shielding device are as follows: Figure 7 As shown, in The average magnetic noise within the range is lower than It is close to the inherent magnetic noise of a cylindrical nanocrystalline alloy magnetic shielding device of this specification.

[0105] Through the nanocrystalline alloy magnetic shielding device and its preparation method with ultra-low magnetic noise described in the above embodiments of this disclosure, experimental data demonstrates that the five-layer structure can suppress the average magnetic noise of the magnetic shielding device to below [a certain level]. The magnetic field strength has approached the device's inherent noise limit, providing a necessary and near-perfect ultra-low magnetic noise environment for cutting-edge technologies such as atomic magnetometers and dark matter detection. The three-layer structure achieves this with significantly lower material and manufacturing costs than a five-layer design. Its superior performance provides an extremely high cost-effectiveness, offering a feasible technical solution for large-scale applications in fields such as biomagnetic imaging and inertial navigation.

[0106] In one possible implementation of the above embodiments, the non-magnetic support frame 101 is a cylindrical or square structure.

[0107] In this embodiment, please refer to Figure 8 , Figure 8 This is a schematic diagram of a cylindrical nanocrystalline alloy magnetic shielding device with ultra-low magnetic noise, according to an embodiment of this disclosure. Figure 8 As shown:

[0108] Figure 8 The device shown is a cylindrical nanocrystalline alloy magnetic shielding device that uses a cylindrical non-magnetic support frame as a mechanical support and shaping structure. The main body of the frame is cylindrical, and the diameter, height and other dimensions can be designed and adjusted according to the actual application scenario.

[0109] A cylindrical, non-magnetic support frame is typically used as a basic component to fix a multi-layer magnetic shielding structure (not shown in the figure) through a winding process. In actual assembly, a single-layer magnetic shielding sheet 103 is tightly wound around the cylindrical outer surface of the non-magnetic support frame and fixed with an insulating adhesive to form the main body of the cylindrical magnetic shielding device.

[0110] Furthermore, to achieve a completely sealed shielded cavity, a disc-shaped end cap that matches the cylindrical, non-magnetic support frame is typically required. This end cap is also made of a non-magnetic material and covered with the same number of layers of nanocrystalline alloy magnetic shielding sheets, ultimately assembled and packaged with the main body, which is wound with the shielding layer. If necessary, through-holes can be pre-drilled in the end cap or the main body to accommodate functional requirements such as cable passage, optical pathways, or sensor placement.

[0111] Please refer to further information. Figure 9 , Figure 9 This is a schematic diagram of a square nanocrystalline alloy magnetic shielding device with ultra-low magnetic noise, according to an embodiment of this disclosure. Figure 9 As shown:

[0112] Figure 9 The device shown is a square nanocrystalline alloy magnetic shielding device that uses a square non-magnetic support frame as a mechanical support and shaping structure. The main body of the frame has a cuboid structure, and the length, width and height dimensions can be designed and adjusted according to the actual application scenario.

[0113] Square nanocrystalline alloy magnetic shielding devices can use a square non-magnetic support frame as the core support structure. This frame is a six-sided cubic frame, and its size can be customized according to application requirements.

[0114] The six inner surfaces (or outer surfaces) of the square non-magnetic support frame are respectively fixed with multi-layer magnetic shielding structures of specific dimensions through a bonding process. Figure 9 (Not shown in the image). Specifically, single-layer or multi-layer nanocrystalline alloy magnetic shielding sheets, which have been cut and die-cut to match the dimensions of the skeleton surface, are flatly pressed onto the various planes of the skeleton, including the four sides, top surface, and bottom surface, using an insulating adhesive, and finally assembled to form a complete cubic shielding cavity.

[0115] Similar to cylindrical devices, this square, non-magnetic support frame is also made of non-magnetic material to ensure that it does not introduce magnetic interference. Compared to cylindrical structures, square structures are easier to match and integrate with the internal spaces of most electronic instrument compartments and equipment enclosures, thus providing another important form of engineering application.

[0116] In one possible implementation of the above embodiments, the device further includes a demagnetizing coil 108.

[0117] In this embodiment, please refer to Figures 8 to 9 , Figures 8 to 9 The structure shown by the black line is the demagnetizing coil 108.

[0118] The demagnetizing coil 108 is fixed to the magnetic shielding device by winding or attaching. This integration method ensures that a tight electromagnetic coupling is formed between the demagnetizing coil 108 and the nanocrystalline alloy material that serves as the main body of the magnetic shielding function.

[0119] When the device is demagnetized, an alternating current with gradually decreasing amplitude is passed through the demagnetizing coil 108. This current generates a synchronously decaying alternating magnetic field in the coil, which directly penetrates and acts on the nanocrystalline alloy material in the multilayer magnetic shielding structure 102, driving its internal magnetic domains to undergo repeated magnetization. As the magnetic field strength decays to zero, the magnetic domain orientation is fully randomized, thereby achieving a near-zero remanence state.

[0120] By directly integrating the demagnetizing coil 108 onto the multilayer magnetic shielding structure 102, it is ensured that the attenuated magnetic field acts directly on the magnetic shielding material, improving the consistency and thoroughness of the demagnetizing effect, while also facilitating internal thermal management of the device. This design is a key functional guarantee for achieving and maintaining extremely low intrinsic magnetic noise in magnetic shielding devices.

[0121] The nanocrystalline alloy magnetic shielding device and its fabrication method with ultra-low magnetic noise, as described in the above embodiments of this disclosure, achieves the most direct electromagnetic coupling between the attenuated magnetic field generated by the coil and the nanocrystalline alloy material by directly integrating the demagnetizing coil 108 onto the surface of the multilayer magnetic shielding structure 102. This design ensures that the attenuated magnetic field can act efficiently and without loss on the entire magnetic shield, achieving precise driving of the internal magnetic domains and thus reaching a more thorough near-zero remanence state. This integration method combines the functional component (coil) and the functional structure (shielding layer) into one, simplifying the overall structure.

[0122] Please refer to Figure 10 , Figure 10 This is a schematic flowchart of a method for fabricating a nanocrystalline alloy magnetic shielding device according to an embodiment of this disclosure. The method may include the following steps:

[0123] Step S1001: Provide Finemet type amorphous alloy strip.

[0124] A width of [missing information] is prepared by single-roller spinning method. Thickness is Finemet type amorphous alloy strip.

[0125] As a preferred embodiment, a width of Thickness is The strip material is used as raw material.

[0126] Step S1002: Annealing and crystallization treatment is performed on the Finemet type amorphous alloy strip to obtain nanocrystalline alloy strip.

[0127] In this embodiment, the annealing crystallization treatment is a three-step annealing process performed under an inert gas or vacuum atmosphere, including:

[0128] First annealing stage: In Anneal for 50-80 minutes;

[0129] Second annealing stage: In Anneal for 30-45 minutes;

[0130] Third annealing stage: In Anneal for 70-100 minutes.

[0131] Through this three-step annealing process, a grain size of [size missing] can be obtained. single phase Nanocrystalline alloy strip.

[0132] Step S1003: Splice multiple nanocrystalline alloy strips together and set an overlapping area at the splicing point of adjacent nanocrystalline alloy strips to form a single-layer magnetic shielding sheet.

[0133] In this embodiment, a thickness of [thickness value missing] can be used. PET film, used as a non-magnetic protective film, with a thickness of The insulating adhesive is bonded to the nanocrystalline alloy strip.

[0134] As a preferred embodiment, a thickness of [missing information] can be used. PET film and thickness of Epoxy resin adhesive.

[0135] Multiple nanocrystalline alloy strips are laminated in parallel onto a wide PET film with insulating adhesive. To ensure magnetic continuity, a spacing of [width value missing] is set between adjacent strips. The overlapping area.

[0136] In one possible implementation of the above embodiments, multiple nanocrystalline alloy strips are spliced ​​together, and an overlap area is set at the splicing point of adjacent nanocrystalline alloy strips to form a single-layer magnetic shielding sheet, including:

[0137] Multiple nanocrystalline alloy strips are available;

[0138] Peel off the protective film on the upper surface of the nanocrystalline alloy strip, and splice the nanocrystalline alloy strip in parallel onto a pre-set width base protective film through the non-magnetic protective film on its lower surface, forming an overlapping area at the splicing point.

[0139] A non-magnetic protective film is covered on the upper surface of the assembled structure to form a single-layer magnetic shielding sheet.

[0140] In a preferred embodiment, multiple nanocrystalline alloy strips with attached PET films can be bonded parallel to each other on their lower surfaces. A single nanocrystalline alloy layer magnetic shielding sheet is prepared by splicing wide PET films onto an insulating adhesive.

[0141] During the lamination process, the original PET film on the surface of the nanocrystalline alloy strip is peeled off. To ensure the continuity of the seams at the joints of the nanocrystalline alloy strip, a [missing information - likely a design element] is installed at the splicing point. The wide overlapping area suppresses magnetic flux leakage at the joints and enhances structural stability.

[0142] Finally, an insulating adhesive is used to cover the upper surface of the single-layer nanocrystalline alloy magnetic shielding sheet with another layer of material with a width of [missing information]. PET film is used to form a protective layer and enhance insulation.

[0143] Step S1004: At least one single-layer magnetic shielding sheet is stacked or wound to form a multi-layer magnetic shielding structure, and then fixed to a non-magnetic support frame to assemble a magnetic shielding device.

[0144] In this embodiment, the step employs different molding processes depending on the shape requirements of the final device: for cylindrical devices, a single-layer magnetic shielding sheet is wound around the cylindrical frame a specific number of times; for square devices, a cut single-layer magnetic shielding sheet is attached to the six surfaces of the square frame.

[0145] In one possible implementation of the above embodiments, in the step of stacking or winding to form a multilayer magnetic shielding structure, as a first embodiment, when the number of layers of the single-layer magnetic shielding sheet being wound is 1, the assembly process of the cylindrical nanocrystalline alloy magnetic shielding device includes the following steps:

[0146] Step a1: The single-layer nanocrystalline alloy magnetic shielding sheet is cut and die-cut to obtain a width of... Single-layer nanocrystalline alloy magnetic shielding sheet and diameter A single-layer circular nanocrystalline alloy magnetic shielding sheet.

[0147] Step a2, as follows Figure 8 The cylindrical nanocrystalline alloy magnetic shielding device shown has a width of [missing information] in step a1. The single-layer nanocrystalline alloy magnetic shielding sheet has a diameter of ,high The main body of a single-layer cylindrical nanocrystalline alloy magnetic shielding device is obtained by wrapping and bonding a layer of non-magnetic cylindrical support frame.

[0148] Step a3, the diameter of the single layer in step a1 The circular nanocrystalline alloy magnetic shielding sheet is attached to the non-magnetic circular support frame with double-sided adhesive to obtain the end cap of the single-layer cylindrical nanocrystalline alloy magnetic shielding device.

[0149] Step a4: Wrap demagnetizing wire around the main body of the single-layer cylindrical nanocrystalline alloy magnetic shielding device in step a2 and the end cap part in step a3, and assemble them to finally obtain the single-layer cylindrical nanocrystalline alloy magnetic shielding device.

[0150] Furthermore, as a second embodiment, when the number of layers of the single-layer magnetic shielding sheet being wound is 3, the assembly process of the cylindrical nanocrystalline alloy magnetic shielding device includes the following steps:

[0151] Step b1 involves cutting and die-cutting the single-layer nanocrystalline alloy magnetic shielding sheet to obtain a width of... Single-layer nanocrystalline alloy magnetic shielding sheet and diameter A single-layer circular nanocrystalline alloy magnetic shielding sheet. Three single-layer circular nanocrystalline alloy magnetic shielding sheets are laminated together using a lamination technique to obtain a diameter... A three-layer circular nanocrystalline alloy magnetic shielding sheet.

[0152] Step b2, the width in step b1 is The single-layer nanocrystalline alloy magnetic shielding sheet has a diameter of ,high The three layers of cylindrical nanocrystalline alloy magnetic shielding device are obtained by wrapping three turns of the non-magnetic cylindrical support frame and bonding them together.

[0153] Step b3, the diameter in step b1 The three-layer circular nanocrystalline alloy magnetic shielding sheet is attached to the non-magnetic circular support frame with double-sided adhesive to obtain the end cap of the three-layer cylindrical nanocrystalline alloy magnetic shielding device.

[0154] Step b4: Wrap demagnetizing wire around the main body of the three-layer cylindrical nanocrystalline alloy magnetic shielding device from step b2 and the end cap from step b3 and assemble them to finally obtain the three-layer cylindrical nanocrystalline alloy magnetic shielding device.

[0155] Furthermore, as a third embodiment, when the number of layers of the single-layer magnetic shielding sheet being wound is 5, the assembly process of the cylindrical nanocrystalline alloy magnetic shielding device includes the following steps:

[0156] Step c1 involves cutting and die-cutting the single-layer nanocrystalline alloy magnetic shielding sheet to obtain a width of... Single-layer nanocrystalline alloy magnetic shielding sheet and diameter A single-layer circular nanocrystalline alloy magnetic shielding sheet. Five single-layer circular nanocrystalline alloy magnetic shielding sheets are laminated together using a lamination technique to obtain a diameter... A five-layer circular nanocrystalline alloy magnetic shielding sheet.

[0157] Step c2, the width in step c1 is The single-layer nanocrystalline alloy magnetic shielding sheet has a diameter of ,high The body of the five-layer cylindrical nanocrystalline alloy magnetic shielding device is obtained by wrapping five layers around and bonding them together on a non-magnetic cylindrical support frame.

[0158] Step c3, the diameter in step c1 The five-layer circular nanocrystalline alloy magnetic shielding sheet is bonded to the non-magnetic circular support frame with double-sided adhesive to obtain the end cap of the five-layer cylindrical nanocrystalline alloy magnetic shielding device.

[0159] Step c4 involves winding demagnetizing wire around the main body of the five-layer cylindrical nanocrystalline alloy magnetic shielding device from step c2 and the end cap from step c3, and then assembling them to obtain the five-layer cylindrical nanocrystalline alloy magnetic shielding device.

[0160] Cylindrical nanocrystalline alloy magnetic shielding devices with different numbers of layers, prepared in the first to third embodiments described above, were placed inside a permalloy magnetic shielding system, and magnetic noise at the center position was tested. Before each test, both the permalloy magnetic shielding system and the cylindrical nanocrystalline alloy magnetic shielding devices were demagnetized to eliminate the influence of geomagnetization on the magnetic shielding devices themselves. The magnetic noise test results are as described above. Figures 6 to 7 The diagram shows a comparison of magnetic noise test results for a single-layer cylindrical nanocrystalline alloy magnetic shielding device (circle), a three-layer cylindrical nanocrystalline alloy magnetic shielding device (triangle), and a permalloy magnetic shielding system (square) from the related art serving as a reference. The horizontal axis represents frequency, and the vertical axis represents magnetic noise.

[0161] As shown by the curve, the permalloy magnetic shielding system in The average magnetic noise within the range is approximately This represents the typical noise floor of related technologies without the devices described in this disclosure, forming the baseline for this performance comparison. The single-layer cylindrical nanocrystalline alloy magnetic shielding device... The average magnetic noise within the range is reduced to Compared with the permalloy magnetic shielding system, the magnetic noise is reduced by more than 50%, indicating that even a single-layer cylindrical nanocrystalline alloy magnetic shielding device in the embodiments of this disclosure can have a significant suppression effect on the magnetic noise generated by permalloy.

[0162] The three-layer cylindrical nanocrystalline alloy magnetic shielding device is internal The average magnetic noise within the range is further reduced to This indicates that increasing the thickness of the cylindrical nanocrystalline alloy magnetic shielding device can further enhance the suppression effect on magnetic noise generated by permalloy.

[0163] The magnetic noise test results of the five-layer cylindrical nanocrystalline alloy magnetic shielding device are as follows: Figure 7 As shown, in The average magnetic noise within the range is lower than It is close to the inherent magnetic noise of a cylindrical nanocrystalline alloy magnetic shielding device of this specification.

[0164] Furthermore, as a fourth embodiment, when the number of layers in the stacked single-layer magnetic shielding sheet is one, the assembly process of the square nanocrystalline alloy magnetic shielding device includes the following steps:

[0165] Step d1 involves cutting and die-cutting the single-layer nanocrystalline alloy magnetic shielding sheet to obtain a width of... A single-layer square nanocrystalline alloy magnetic shielding sheet.

[0166] Step d2, the width in step d1 is A single-layer square nanocrystalline alloy magnetic shielding sheet is bonded to a surface with a size of [missing information - likely a unit of measurement] using double-sided adhesive. On the six surfaces of a non-magnetic square support frame, demagnetizing lines are then evenly distributed on each surface, ultimately resulting in... Figure 9 The square single-layer nanocrystalline alloy magnetic shielding device shown is shown.

[0167] Furthermore, as a fifth embodiment, when the number of layers of the stacked single-layer magnetic shielding sheet is 5, the assembly process of the square nanocrystalline alloy magnetic shielding device includes the following steps:

[0168] Step e1 involves cutting and die-cutting the single-layer nanocrystalline alloy magnetic shielding sheet to obtain a width of... A single-layer square nanocrystalline alloy magnetic shielding sheet. Five single-layer square nanocrystalline alloy magnetic shielding sheets were laminated together using a lamination technique to obtain a sheet with dimensions of [size missing]. A five-layer square nanocrystalline alloy magnetic shielding sheet.

[0169] Step e2, convert the six widths from step e1 to... The five-layer square nanocrystalline alloy magnetic shielding sheet is bonded to a surface with a size of [missing information - likely a unit of measurement]. On the six surfaces of a non-magnetic square support frame, demagnetizing lines are then evenly distributed on each surface, ultimately resulting in... Figure 9 The square five-layer nanocrystalline alloy magnetic shielding device shown is shown.

[0170] Square nanocrystalline alloy magnetic shielding devices with different numbers of layers, prepared in the fourth and fifth embodiments above, were placed inside a permalloy magnetic shielding system, and magnetic noise at the center position was tested. Before each test, both the permalloy magnetic shielding system and the square nanocrystalline alloy magnetic shielding devices were demagnetized to eliminate the influence of geomagnetization on the magnetic shielding devices themselves. The magnetic noise test results are as follows: Figure 11 As shown, Figure 11 This is a schematic diagram comparing the magnetic noise of a square nanocrystalline alloy magnetic shielding device with ultra-low magnetic noise, as described in an embodiment of this disclosure, with that of a permalloy system. The permalloy magnetic shielding system used in this embodiment has internal... The average magnetic noise within the range is approximately .from Figure 11 As can be clearly seen, the single-layer square nanocrystalline alloy magnetic shielding device inherently possesses... The average magnetic noise within the range is reduced to Compared to the permalloy magnetic shielding system, the magnetic noise is reduced by more than 30%, indicating that the single-layer square nanocrystalline alloy magnetic shielding device of this embodiment has a certain suppression effect on the magnetic noise generated by permalloy. Furthermore... Figure 11 The five-layer square nanocrystalline alloy magnetic shielding device shown in the article has an average magnetic noise of approximately [missing information]. It is close to the inherent magnetic noise of a square nanocrystalline alloy magnetic shielding device of this specification.

[0171] In summary, the nanocrystalline alloy magnetic shielding device provided in this embodiment has a significant suppression effect on the magnetic noise generated by the permalloy magnetic shielding system, and the nanocrystalline alloy magnetic shielding device has extremely low inherent magnetic noise.

[0172] This invention also provides a magnetic shielding system. The nanocrystalline alloy magnetic shielding device with ultra-low magnetic noise described in the above embodiments of this disclosure can be applied to a magnetic shielding system as a hardware unit in the magnetic shielding system.

[0173] Although embodiments of the present disclosure have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present disclosure, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A nanocrystalline alloy magnetic shielding device with ultra-low magnetic noise, characterized in that, include: Nanocrystalline alloy strip obtained by annealing and crystallization treatment of Finemet-type amorphous alloy strip; A non-magnetic protective film is disposed on at least one surface of the nanocrystalline alloy strip, and the non-magnetic protective film is bonded to the nanocrystalline alloy strip by an insulating adhesive. A single-layer magnetic shielding sheet is formed by splicing and die-cutting multiple nanocrystalline alloy strips. During the splicing process, an overlap area is provided at the splicing points of adjacent nanocrystalline alloy strips; wherein the width of the overlap area is... To balance magnetic properties with structural design; A multi-layer magnetic shielding structure formed by stacking or winding at least one of the single-layer magnetic shielding sheets; and a non-magnetic support frame for supporting and fixing the multi-layer magnetic shielding structure; The microstructure of the nanocrystalline alloy strip is predominantly single-phase. Nanocrystalline phase, and the grain size of the nanocrystals is ; The annealing and crystallization treatment is a three-step annealing process performed under an inert gas or vacuum atmosphere, including: First annealing stage: In Lower Annealing minute; Second annealing stage: In Lower Annealing minute; Third annealing stage: In Lower Annealing minute.

2. The device according to claim 1, characterized in that, The non-magnetic protective film is a polyethylene terephthalate film with a thickness of [missing information]. The thickness of the insulating adhesive is .

3. The device according to claim 1, characterized in that, The non-magnetic support frame is a cylindrical or square structure.

4. The device according to claim 1, characterized in that, It also includes a demagnetizing coil integrated into the multi-layer magnetic shielding structure.

5. A method for preparing a nanocrystalline alloy magnetic shielding device, characterized in that, include: We offer fine-mesh amorphous alloy strips. The Finemet-type amorphous alloy strip is subjected to annealing and crystallization treatment to obtain a nanocrystalline alloy strip; Multiple nanocrystalline alloy strips are spliced ​​together, and an overlap area is set at the splicing point of adjacent nanocrystalline alloy strips to form a single-layer magnetic shielding sheet; wherein, the width of the overlap area is... To balance magnetic properties with structural design; At least one of the single-layer magnetic shielding sheets is stacked or wound to form a multi-layer magnetic shielding structure, and fixed to a non-magnetic support frame to assemble a magnetic shielding device. The microstructure of the nanocrystalline alloy strip is predominantly single-phase. Nanocrystalline phase, and the grain size of the nanocrystals is ; The annealing and crystallization treatment is a three-step annealing process performed under an inert gas or vacuum atmosphere, including: First annealing stage: In Lower Annealing minute; Second annealing stage: In Lower Annealing minute; Third annealing stage: In Lower Annealing minute.

6. The method according to claim 5, characterized in that, The step of splicing multiple nanocrystalline alloy strips together and setting an overlap area at the splicing point of adjacent nanocrystalline alloy strips to form a single-layer magnetic shielding sheet includes: Multiple nanocrystalline alloy strips are available; Peel off the protective film on the upper surface of the nanocrystalline alloy strip, and splice the nanocrystalline alloy strip in parallel onto a base protective film of a predetermined width through the non-magnetic protective film on its lower surface, forming the overlapping area at the splicing point. A non-magnetic protective film is covered on the upper surface of the assembled structure to form the single-layer magnetic shielding sheet.

7. The method according to claim 5, characterized in that, After the magnetic shielding device is assembled, the process further includes: demagnetizing the magnetic shielding device using an alternating magnetic field with gradually decreasing amplitude.

8. A magnetic shielding system, characterized in that, Including nanocrystalline alloy magnetic shielding devices with ultra-low magnetic noise as described in any one of claims 1-4.

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