Composite magnetic sheet filled with nanocrystalline slotted soft magnetic alloy powder and preparation method of composite magnetic sheet

Abstract

The invention belongs to the technical field of magnetic shielding materials, and particularly relates to a nanocrystalline slotting and soft magnetic alloy powder filling composite magnetic sheet and a preparation method thereof. The composite magnetic sheet comprises a magnetic material layer formed by alternately compounding a nanocrystalline material layer and a double-faced adhesive tape, the magnetic material layer is provided with regularly distributed slotting structures, and the slotting structures are filled with soft magnetic alloy powder. The preparation method comprises the following steps: alternately compounding a nanocrystalline material layer and a double-faced adhesive tape to form a magnetic material layer, and performing die cutting to form a regularly distributed slotting structure; or the nanocrystalline material composite layer is subjected to die cutting to form a regularly-distributed through slotting structure, and then the structure is compounded with the composite layer which is not slotted to obtain the magnetic material layer; and then filling and fixing the slotting structure by adopting soft magnetic alloy powder to obtain the composite magnetic sheet. According to the invention, the defect of easy magnetic saturation due to local lack of magnetic materials after slotting can be avoided, and the obtained composite magnetic sheet has low loss and high saturation current at the same time.

Description

Technical Field

[0001] This invention belongs to the field of magnetic shielding materials technology, specifically relating to a nanocrystalline slotted soft magnetic alloy powder composite magnetic sheet and its preparation method. Background Technology

[0002] With the popularization of wireless power charging (WPC) and near field communication (NFC) technologies, more and more electronic products are starting to be equipped with the above-mentioned functional modules, and magnetic field shielding sheets are required in these modules.

[0003] The materials used for magnetic field shielding sheets mainly include amorphous and nanocrystalline ribbons, ferrites, and polymer sheets containing magnetic powder. Ferrites and polymer sheets containing magnetic powder, due to their low permeability and low saturation magnetic induction, are difficult to make very thin as shielding materials. Amorphous and nanocrystalline materials, on the other hand, are excellent ultrathin soft magnetic materials with the natural advantages of high intrinsic permeability and high saturation magnetic induction, making them ideal for ultrathin shielding materials, unmatched by other materials. However, when a high-frequency AC magnetic field is applied to amorphous ribbons, eddy current losses on the ribbon surface can degrade application functionality, or cause efficiency reduction and heat generation during wireless charging. To meet the shielding requirements, post-processing is needed to reduce eddy current losses. Reducing the area of ​​the magnetic material can lower eddy current losses; this involves dividing the amorphous or nanocrystalline magnetic sheet into smaller units (i.e., fragmentation or magnetic fragmentation). The small magnetic flux, small area, and small eddy current of the fragmented single unit are small. At the same time, the large circulating eddy current within the entire magnetic sheet area is disconnected, which reduces the loss after coupling and reduces the heat generation.

[0004] However, the overall magnetic fragmentation process typically involves rolling with a roller bearing protrusions, resulting in random fragmentation. This makes it difficult to control the uniformity of the fragmentation (such as fragment size and crack uniformity) and is inconvenient for adjusting the diverse properties of the magnetic sheet. Invention patents CN 110913674 B, CN 112103641 B, and CN 112103642 B all describe methods for forming regular slits, through-holes, and cracks in a predetermined area of ​​the magnetic field shielding sheet, replacing conventional magnetic fragmentation processes or structures. This allows for the manufacture of shielding sheets with diverse magnetic permeabilities and simplifies the manufacturing process. However, the slits or through-holes formed by punching or similar methods are prone to magnetic saturation due to localized lack of magnetic material, leading to a decrease in saturation current. Summary of the Invention

[0005] In view of the shortcomings and deficiencies of the existing technology, the primary objective of this invention is to provide a composite magnetic sheet with nanocrystalline slotted soft magnetic alloy powder.

[0006] Another object of the present invention is to provide a method for preparing the above-mentioned composite magnetic sheet.

[0007] The objective of this invention is achieved through the following technical solution: A nanocrystalline grooved soft magnetic alloy powder composite magnetic sheet includes a magnetic material layer composed of alternating layers of nanocrystalline material and double-sided adhesive. The magnetic material layer has regularly distributed grooved structures, and the grooved structures are filled with soft magnetic alloy powder.

[0008] Furthermore, the nanocrystalline material layer is composed of Fe. (100-x-y-z-α-β-γ) M x Cu y M' z Si α B β X γ Where M is Co and / or Ni, M' is at least one element selected from Nb, V, Mo, Ta, W, Zr, Hf, Ti, Cr, Mn, Al, Sc, Y, Zn, and Sn, and X is at least one element selected from C, Ge, P, Ga, Sb, In, and S; 0≤x≤40, 0.1≤y≤1.5, 0≤z≤5, 1≤α≤18, 5≤β≤15, and 0≤γ≤5. The preferred nanocrystalline material layer composition is Fe. (100-y-z-α-β) Cu y Nb z Si α B β , 0.5≤y≤1.5, 1≤z≤5, 4≤α≤16, 6≤β≤10.

[0009] Furthermore, the thickness of a single layer of the nanocrystalline material layer is 10~30μm, preferably 14~25μm; the number of nanocrystalline material layers in the magnetic material layer is 1~12.

[0010] Furthermore, the nanocrystalline material layer may or may not undergo magnetic fragmentation treatment; the size of the fragments after magnetic fragmentation treatment is 0.02~3mm, and the width of the fracture gaps is 0.02~10μm.

[0011] Furthermore, the magnetic permeability of the nanocrystalline material layer is 500~18000@100kHz, preferably 3000~15000@100kHz.

[0012] Furthermore, the thickness of a single layer of the double-sided adhesive is 1~5μm.

[0013] Furthermore, the slotted structure can be either through-hole or non-through-hole.

[0014] Furthermore, the slotted structure is radially linear, curved, or fan-shaped; the average width of the slotted structure is 0.05~8mm.

[0015] Furthermore, the projected area of ​​the slotted structure in the magnetic material layer accounts for 0.1% to 50%.

[0016] Further, the soft magnetic alloy powder is at least one of the following: carbonyl iron powder, iron-silicon soft magnetic alloy powder, iron-aluminum soft magnetic alloy powder, iron-nickel soft magnetic alloy powder, iron-silicon-aluminum soft magnetic alloy powder, iron-silicon-aluminum-nickel soft magnetic alloy powder, iron-nickel-molybdenum soft magnetic alloy powder, iron-cobalt soft magnetic alloy powder, iron-chromium soft magnetic alloy powder, iron-silicon-chromium soft magnetic alloy powder, manganese-zinc soft magnetic ferrite powder, nickel-zinc soft magnetic ferrite powder, cobalt-based amorphous soft magnetic alloy powder, cobalt-based nanocrystalline soft magnetic alloy powder, iron-based amorphous soft magnetic alloy powder, and iron-based nanocrystalline soft magnetic alloy powder, with a particle size of 0.5~200μm.

[0017] Furthermore, the permeability of the soft magnetic alloy powder is 20~300@1MHz.

[0018] Furthermore, the soft magnetic alloy powder is filled with powder and sealed with a protective film, or it is mixed with 0.1% to 5% (by mass percentage of the soft magnetic alloy powder) of a bonding resin and filled and bonded. Preferably, the bonding resin can be epoxy resin, silicone resin, polyurethane resin, or acrylic resin, etc.

[0019] The preparation method of the above-mentioned composite magnetic sheet includes the following preparation steps: (1) A magnetic material layer is formed by alternating layers of nanocrystalline material and double-sided adhesive, and then a regularly distributed grooved structure is formed on the magnetic material layer by die cutting; or a composite layer formed by alternating layers of nanocrystalline material and double-sided adhesive is formed by die cutting to form a regularly distributed through grooved structure, and then combined with an ungrooved composite layer to obtain a magnetic material layer. (2) The grooved structure is filled by forming a soft magnetic alloy powder and a bonding resin curing sheet corresponding to the grooved structure by punching, or by scraping a soft magnetic alloy powder and bonding resin mixture slurry into the grooved structure and drying and curing it, or by positioning and filling the grooved structure with soft magnetic alloy powder and sealing it with a protective film to obtain a composite magnetic sheet.

[0020] Compared with the prior art, the beneficial effects of the present invention are: This invention reduces magnetic loss in a magnetic sheet by creating a regularly distributed slotted structure on a nanocrystalline magnetic material layer, and facilitates controllable adjustment of the sheet's performance. By filling the slotted structure with soft magnetic alloy powder, the defect of local magnetic saturation due to insufficient magnetic material after slotting can be avoided. The resulting composite magnetic sheet exhibits both lower loss and higher saturation current. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of the composite magnetic sheet in Example 1.

[0022] Figure 2This is a schematic diagram of the AA-direction cross-section of the composite magnetic sheet in Example 1.

[0023] Figure 3 This is a schematic diagram of the overall structure of the composite magnetic sheet in Example 2.

[0024] Figure 4 This is a schematic diagram of the overall structure of the composite magnetic sheet in Example 3.

[0025] Figure 5 This is a schematic diagram of the overall structure of the composite magnetic sheet in Example 4.

[0026] Figure 6 This is a schematic diagram of the overall structure of the composite magnetic sheet in Example 5.

[0027] Figure 7 This is a schematic diagram of the AA-direction cross-section of the composite magnetic sheet in Example 5.

[0028] Figure 8 This is a schematic diagram of the overall structure of the composite magnetic sheet in Example 6.

[0029] Figure 9 This is a schematic diagram of the AA-direction cross-section of the composite magnetic sheet in Example 6.

[0030] The numbers in the diagram are explained as follows: 1-Magnetic material layer, 1-1-Nanocrystalline material layer, 1-2-Double-sided adhesive, 2-Groove structure, 3-Soft magnetic alloy powder, 4-Protective film. Detailed Implementation

[0031] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto. Example 1

[0032] A nanocrystalline slotted soft magnetic alloy powder composite magnetic sheet, the overall structural schematic diagram and the AA-direction cross-sectional schematic diagram are shown below. Figure 1 and Figure 2 As shown, it includes a magnetic material layer 1 composed of an alternating composite of a nanocrystalline material layer 1-1 and double-sided adhesive 1-2. The magnetic material layer 1 has regularly distributed grooved structures 2, and the grooved structures 2 are filled with soft magnetic alloy powder 3.

[0033] The nanocrystalline material layer is composed of Fe. 73.8 Cu1Nb3Si 15.2 B7 (at.%), the nanocrystalline material layer has a single-layer thickness of 18~20μm, and the magnetic material layer contains 4 nanocrystalline material layers. The nanocrystalline material layers undergo magnetic fragmentation treatment, with fragment sizes of 0.2~3mm and fracture gap widths of 0.05~2μm. The magnetic permeability of the fragmented nanocrystalline material layer is 8000@100kHz. The double-sided adhesive has a single-layer thickness of 3μm.

[0034] The slotted structure is non-through; the top three nanocrystalline material layers in the magnetic material layer are slotted, while the bottom layer is not. The slotted structure is a wide, radial, straight line with an average width of 5 mm and a projected area of ​​20% in the magnetic material layer.

[0035] The soft magnetic alloy powder is an iron-silicon-aluminum soft magnetic alloy powder with a particle size of 0.5~100μm and a magnetic permeability of 150@1MHz.

[0036] The nanocrystalline slotted soft magnetic alloy powder composite magnetic sheet is prepared by the following method: (1) A composite layer consisting of three layers of nanocrystalline material and double-sided adhesive is formed by alternating composite layers. After being crushed and magnetically treated by roller, it is die-cut to form a regularly distributed through-grooved structure. Then, it is combined with a composite layer consisting of one layer of nanocrystalline material and double-sided adhesive to obtain a magnetic material layer.

[0037] (2) After scraping a mixture of soft magnetic alloy powder and bonding resin (99wt% iron-silicon-aluminum soft magnetic alloy powder and 1wt% epoxy resin mixture) into the grooved structure of the magnetic material layer, the mixture is dried, cured and filled to obtain a composite magnetic sheet. Example 2

[0038] A nanocrystalline grooved soft magnetic alloy powder composite magnetic sheet, compared with Example 1, has a grooved structure in the shape of a narrow slit radial straight line, an average width of 0.05 mm, and a projected area of ​​2% in the magnetic material layer. Its overall structural schematic diagram is shown below. Figure 3 As shown. Example 3

[0039] A nanocrystalline grooved soft magnetic alloy powder composite magnetic sheet, compared with Example 1, has a grooved structure with a radial curve shape, an average groove width of 2 mm, and a projected area of ​​5% in the magnetic material layer. Its overall structural schematic diagram is shown below. Figure 4 As shown. Example 4

[0040] A nanocrystalline grooved soft magnetic alloy powder composite magnetic sheet, compared with Example 1, has a radial fan-shaped grooved structure, an average groove width of 3 mm, and a projected area of ​​30% in the magnetic material layer. Its overall structural schematic diagram is shown below. Figure 5 As shown. Example 5

[0041] A nanocrystalline slotted soft magnetic alloy powder composite magnetic sheet, the overall structural schematic diagram and the AA-direction cross-sectional schematic diagram are shown below. Figure 6 and Figure 7As shown. The nanocrystalline slotted soft magnetic alloy powder composite magnetic sheet is prepared by the following method: (1) A composite layer consisting of four layers of nanocrystalline material and double-sided adhesive is formed by alternating composites, and then die-cut to form a regularly distributed through-groove structure. The shape of the groove structure is a radial straight line, the average width of the groove structure is 8 mm, and the projection area of ​​the groove structure in the magnetic material layer accounts for 50%, thus obtaining the magnetic material layer.

[0042] (2) The soft magnetic alloy powder and the bonding resin mixture slurry (99wt% iron-silicon-aluminum soft magnetic alloy powder and 1wt% epoxy resin mixture slurry) is molded, dried and cured, and punched to obtain a cured sheet corresponding to the grooved structure in step (1). Then the obtained cured sheet is used to fill the grooved structure to obtain a composite magnetic sheet. Example 6

[0043] A nanocrystalline slotted soft magnetic alloy powder composite magnetic sheet, the overall structural schematic diagram and the AA-direction cross-sectional schematic diagram are shown below. Figure 8 and Figure 9 As shown. The nanocrystalline slotted soft magnetic alloy powder composite magnetic sheet is prepared by the following method: (1) A composite layer consisting of two layers of nanocrystalline material and double-sided adhesive is formed by alternating composite layers. After being crushed by roller and magnetically treated, it is die-cut to form a regularly distributed through-grooved structure. The width of the grooved structure is 5 mm, and the projected area of ​​the grooved structure in the magnetic material layer accounts for 20%. Then it is combined with the composite layer consisting of two layers of nanocrystalline material and double-sided adhesive to obtain the magnetic material layer.

[0044] (2) Fill the slotted structure of the magnetic material layer with iron-silicon-aluminum soft magnetic alloy powder and seal it with protective film 4 to obtain a composite magnetic sheet.

[0045] The performance comparison results of the composite magnetic sheets obtained in the above embodiments and the corresponding slotted structures without soft magnetic alloy powder are shown in Table 1 below.

[0046] Table 1 Comparison of Magnetic Sheet Performance Data Test Cases / Performance Inductance Ls (μH) Resistance Rs (mΩ) Q value Saturation current Is (A) Example 1 8.25 462 11.22 6.6 Example 1: Grooving without filling 8.17 460 11.16 5.8 Example 2 8.46 465 11.43 6.8 Example 2: Grooving without filling 8.44 465 11.40 6.6 Example 3 8.24 460 11.26 6.7 Example 3: Grooving without filling 8.16 459 11.17 5.8 Example 4 8.14 458 11.17 6.2 Example 4: Grooving without filling 8.02 456 11.05 5.3 Example 5 7.87 448 11.04 5.4 Example 5: Grooving without filling 7.63 446 10.75 4.0 Example 6 8.31 465 11.23 6.7 Example 6: Grooving without filling 8.26 464 11.19 5.9 As shown in Table 1, compared to magnetic sheets without soft magnetic alloy powder filling in the slotted structure, the present invention, due to the soft magnetic alloy material filling the slotted structure, increases the overall magnetic flux, resulting in a higher inductance Ls and a higher Q value, thus exhibiting lower losses. Simultaneously, the presence of the soft magnetic alloy material in the slotted structure leads to a more balanced magnetic field distribution, preventing localized magnetic saturation caused by insufficient magnetic material after slotting, resulting in a higher saturation current Is. Generally, the larger the area of ​​the slotted structure in the magnetic material layer, the smaller the magnetic sheet resistance Rs, which can reduce losses during wireless charging and thus reduce heat generation.

[0047] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A composite magnetic sheet with nanocrystalline slotted soft magnetic alloy powder filling, characterized in that: It includes a magnetic material layer composed of alternating layers of nanocrystalline material and double-sided adhesive, wherein the magnetic material layer has regularly distributed grooved structures and the grooved structures are filled with soft magnetic alloy powder.

2. The nanocrystalline grooved filled soft magnetic alloy powder composite magnetic sheet according to claim 1, characterized in that: The nanocrystalline material layer is composed of Fe. (100-x-y-z-α-β-γ) M x Cu y M' z Si α B β X γ , where M is Co and / or Ni, M' is at least one element selected from Nb, V, Mo, Ta, W, Zr, Hf, Ti, Cr, Mn, Al, Sc, Y, Zn, Sn, and X is at least one element selected from C, Ge, P, Ga, Sb, In, S; 0≤x≤40, 0.1≤y≤1.5, 0≤z≤5, 1≤α≤18, 5≤β≤15, and 0≤γ≤5.

3. The nanocrystalline grooved filled soft magnetic alloy powder composite magnetic sheet according to claim 1, characterized in that: The thickness of a single nanocrystalline material layer is 10~30μm; the number of nanocrystalline material layers in the magnetic material layer is 1~12.

4. The nanocrystalline grooved filled soft magnetic alloy powder composite magnetic sheet according to claim 1, characterized in that: The nanocrystalline material layer may or may not undergo magnetic fragmentation treatment; the size of the fragments after magnetic fragmentation treatment is 0.02~3mm, and the width of the fracture gaps is 0.02~10μm; the magnetic permeability of the nanocrystalline material layer is 500~18000@100kHz.

5. The nanocrystalline grooved filled soft magnetic alloy powder composite magnetic sheet according to claim 1, characterized in that: The thickness of a single layer of the double-sided adhesive is 1~5μm.

6. The nanocrystalline grooved filled soft magnetic alloy powder composite magnetic sheet according to claim 1, characterized in that: The slotted structure can be continuous or non-continuous; the shape of the slotted structure can be radial, linear, curved, or fan-shaped; the average width of the slotted structure is 0.05~8mm.

7. The nanocrystalline grooved filled soft magnetic alloy powder composite magnetic sheet according to claim 1, characterized in that: The projected area of ​​the slotted structure in the magnetic material layer accounts for 0.1% to 50%.

8. The nanocrystalline grooved filled soft magnetic alloy powder composite magnetic sheet according to claim 1, characterized in that: The soft magnetic alloy powder is at least one of the following: carbonyl iron powder, iron-silicon soft magnetic alloy powder, iron-aluminum soft magnetic alloy powder, iron-nickel soft magnetic alloy powder, iron-silicon-aluminum soft magnetic alloy powder, iron-silicon-aluminum-nickel soft magnetic alloy powder, iron-nickel-molybdenum soft magnetic alloy powder, iron-cobalt soft magnetic alloy powder, iron-chromium soft magnetic alloy powder, iron-silicon-chromium soft magnetic alloy powder, manganese-zinc soft magnetic ferrite powder, nickel-zinc soft magnetic ferrite powder, cobalt-based amorphous soft magnetic alloy powder, cobalt-based nanocrystalline soft magnetic alloy powder, iron-based amorphous soft magnetic alloy powder, and iron-based nanocrystalline soft magnetic alloy powder, with a particle size of 0.5~200μm; the magnetic permeability of the soft magnetic alloy powder is 20~300@1MHz.

9. The nanocrystalline grooved filled soft magnetic alloy powder composite magnetic sheet according to claim 1, characterized in that: The soft magnetic alloy powder is filled with powder and sealed with a protective film, or it is mixed with 0.1-5% of bonding resin and filled and bonded; the bonding resin is epoxy resin, silicone resin, polyurethane resin or acrylic resin.

10. A method for preparing a composite magnetic sheet according to any one of claims 1 to 9, characterized in that... The preparation steps include the following: (1) A magnetic material layer is formed by alternating layers of nanocrystalline material and double-sided adhesive, and then a regularly distributed grooved structure is formed on the magnetic material layer by die cutting; or a composite layer formed by alternating layers of nanocrystalline material and double-sided adhesive is formed by die cutting to form a regularly distributed through grooved structure, and then combined with an ungrooved composite layer to obtain a magnetic material layer. (2) The grooved structure is filled by forming a soft magnetic alloy powder and a bonding resin curing sheet corresponding to the grooved structure by punching, or by scraping a soft magnetic alloy powder and bonding resin mixture slurry into the grooved structure and drying and curing it, or by positioning and filling the grooved structure with soft magnetic alloy powder and sealing it with a protective film to obtain a composite magnetic sheet.

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