Manufacturing method for sheet-shaped magnetic member

Abstract

To provide a sheet-shaped magnetic member formed by stacking nano-crystalline alloy thin strips with cracks formed in an appropriate shape.SOLUTION: A sheet-shaped magnetic member has nanocrystalline alloy thin strips stacked. An adhesive layer is provided between the nanocrystalline alloy thin strips. The nanocrystalline alloy thin strips are cracked and divided into small pieces. In the sheet-shaped magnetic member, the cracks are hexagonal honeycomb-shaped, and a pair of parallel sides of the hexagons are perpendicular to a casting direction (X direction) of the nanocrystalline alloy thin strips.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a sheet-shaped magnetic member used in magnetic cores, inductors, magnetic shields, etc., and a method for manufacturing the same. [Background technology]

[0002] In recent years, non-contact charging, which uses transmission coils on both the power supply side and the power receiving side to transmit power using electromagnetic induction, has been attracting attention. In non-contact charging, magnetic flux generated in the primary transmission coil of the power supply device generates an electromotive force in the secondary transmission coil of the power receiving device through the housings of the power supply device and the power receiving device, thereby supplying power.

[0003] Non-contact charging is becoming popular for electronic devices such as tablet information terminals, music players, smartphones, and mobile phones. Non-contact charging is also applicable to electronic devices other than those mentioned above, electric vehicles, and drones. It is also applicable to transport vehicles such as forklifts and AGVs (Automated Guided Vehicles), railways, streetcars, and the like.

[0004] In non-contact charging, a magnetic sheet may be combined with the above-mentioned transmission coil (power supply side and power receiving side). This magnetic sheet is mainly used to improve the transmission efficiency of non-contact charging and to prevent leakage of magnetic flux from the non-contact charging circuit to other circuits (magnetic shield). Various methods have been proposed as a method for manufacturing the above-mentioned magnetic sheet (see, for example, Patent Documents 1 to 3). Patent Documents 1 to 3 disclose manufacturing methods including a step of dividing a thin plate-shaped magnetic material contained in a magnetic sheet or a ribbon of an amorphous alloy or nanocrystalline alloy (hereinafter also referred to as an "alloy thin ribbon") into a plurality of pieces for the purpose of improving the Q value or reducing eddy current loss.

[0005] Patent Document 1 discloses a manufacturing method including a step of forming a magnetic sheet by adhering an alloy ribbon to an adhesive layer provided on a sheet substrate, and a step of dividing the alloy ribbon into several pieces by an external force while maintaining the alloy ribbon adhered to the sheet substrate.

[0006] Patent Document 2 discloses a method for producing a magnetic sheet in which an alloy ribbon is heat-treated and then flaked to separate the alloy ribbon into a large number of small pieces or to form cracks in the alloy ribbon. The magnetic sheet has a configuration in which a plurality of alloy ribbons are laminated and adhesive layers or double-sided tape are disposed between the plurality of alloy ribbons. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2008-112830 A [Patent Document 2] Special Publication No. 2015-505166 [Patent Document 3] International Publication No. 2020-235642 Summary of the Invention [Problem to be solved by the invention]

[0008] Nanocrystalline alloy ribbons are used as one of the magnetic materials used in magnetic sheets. Then, cracks may be formed in the nanocrystalline alloy ribbons and the nanocrystalline alloy ribbons may be processed into small pieces. At this time, it is described in prior art documents that a cracking roll is pressed against the nanocrystalline alloy ribbon to form cracks in the nanocrystalline alloy ribbon. Nanocrystalline alloy ribbons have a brittle nature compared to amorphous alloy ribbons, and are more susceptible to cracks.

[0009] Although it is easy to form cracks in nanocrystalline alloy ribbons, the cracks tend to vary in shape, making it difficult to form cracks of a uniform shape. In addition, when used as a magnetic sheet, the optimal size of the pieces may differ depending on the application. Therefore, various studies have been conducted on the formation of cracks, but the optimal form of cracks and the method for producing them have not been determined.

[0010] The present disclosure provides a sheet-shaped magnetic member that provides cracks of an optimal shape and is formed by stacking nanocrystalline alloy ribbons having the cracks formed therein. It also provides a method for manufacturing the sheet-shaped magnetic member that provides cracks of an optimal shape. [Means for solving the problem]

[0011] The present disclosure relates to a sheet-shaped magnetic member in which nanocrystalline alloy ribbons are laminated, an adhesive layer is provided between the nanocrystalline alloy ribbons, and cracks are formed in the nanocrystalline alloy ribbons and the nanocrystalline alloy ribbons are divided into small pieces. The crack is a sheet-like magnetic member having a honeycomb shape made up of interlocking hexagons, with a pair of parallel sides of the hexagon extending along a direction (X direction) perpendicular to the casting direction of the nanocrystalline alloy ribbon. Effect of the Invention

[0012] According to the present disclosure, it is possible to provide a sheet-shaped magnetic member in which nanocrystalline alloy ribbons having cracks formed therein in an appropriate form are laminated, and also to provide a manufacturing method for a sheet-shaped magnetic member in which nanocrystalline alloy ribbons having cracks formed therein in an appropriate form are laminated. [Brief description of the drawings]

[0013] [Figure 1] FIG. 2 is a schematic diagram showing a crack morphology of an example of the present disclosure. [Diagram 2] FIG. 2 is an illustration of a crack in an example of the present disclosure. [Diagram 3] FIG. 13 is a schematic diagram showing a crack morphology in another example of the present disclosure. [Figure 4] FIG. 13 is a schematic diagram showing a crack morphology in yet another example of the present disclosure. [Diagram 5] FIG. 2 is a conceptual diagram of a heat treatment method for obtaining a nanocrystalline alloy ribbon according to the present disclosure. [Figure 6] FIG. 2 is a schematic diagram of an embodiment of forming a crack in the nanocrystalline alloy ribbon of the present disclosure. [Figure 7] 1 is a cross-sectional view of a laminate used in the manufacturing process of the present disclosure. [Figure 8] FIG. 2 is a cross-sectional view of an example in which an adhesive layer is disposed on one surface of a nanocrystalline alloy ribbon having cracks formed therein according to the present disclosure. [Figure 9] FIG. 2 is a side view of an example of a cracking roll used in the embodiments of the present disclosure. [Figure 10] 1A and 1B are a front view and a side view, respectively, of a ring-shaped member having a plurality of protrusions on its outer circumferential surface according to the present disclosure. [Figure 11] 4 is a conceptual diagram of an example of a protrusion of a ring-shaped member according to the present disclosure. FIG. [Figure 12] 1A to 1C are schematic diagrams illustrating an example of a method for producing a sheet-shaped magnetic member in which nanocrystalline alloy ribbons according to the present disclosure are stacked. [Figure 13] FIG. 2 is a schematic diagram of an example of a sheet-shaped magnetic member (five layers) according to the present disclosure. [Figure 14] FIG. 2 is a diagram showing the state in which the tips of the protrusions of a cracking roll come into contact with the nanocrystalline alloy ribbon of the present disclosure. [Figure 15] 1 is an observation photograph (observation A) of a crack formed in the nanocrystalline alloy ribbon of the present disclosure. [Figure 16] FIG. 16 is a replica of the crack lines in the photograph of FIG. 15. [Figure 17] FIG. 13 is a diagram showing the length of the pieces. [Figure 18] 13 is a graph showing the value of Q calculated based on the measurement results. [Figure 19] 1 is a graph showing measured Ls values. [Figure 20] 1 is a graph showing measured Rs values. [Figure 21] FIG. 2 is a diagram illustrating a measuring device used in the evaluation of the present embodiment. [Figure 22] FIG. 2 is a schematic side view of a sheet-shaped magnetic member (25 layers) according to the present disclosure. [Figure 23] 1 is an observation photograph (observation B) of a crack formed in the nanocrystalline alloy ribbon of the present disclosure. [Figure 24] FIG. 24 is a replica of the crack lines in the photograph of FIG. 23. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The embodiments of the present disclosure will be described below with reference to the drawings. Note that the drawings are merely examples, and the dimensional ratios in the drawings do not necessarily represent the actual dimensional ratios. In addition, the present disclosure is not limited to those shown in the drawings, and can be modified as appropriate.

[0015] The nanocrystalline alloy ribbon of the present disclosure has cracks formed therein and is divided into small pieces by the cracks. FIG. 1 is a schematic diagram showing the shape of the cracks in one embodiment of the present disclosure. The shape of the cracks is a combination of hexagons, forming a so-called honeycomb shape. A pair of parallel sides 7 of the hexagons are aligned along a direction (X direction) perpendicular to the casting direction of the nanocrystalline alloy ribbon. Here, the casting direction of the nanocrystalline alloy ribbon is indicated as the Y direction. Also, the shape is such that elongated small pieces are stacked in the Y direction in the X direction, and rows of the stacked small pieces in the Y direction are arranged in the X direction, and adjacent pieces in the X direction are arranged alternately.

[0016] Fig. 2 shows a schematic diagram of the crack in the hexagon. If the hexagon is a regular hexagon, La / L in Fig. 2 is 1.15473. The hexagon of the present disclosure is preferably a hexagon that is elongated in the X direction. For this reason, it is preferable for the hexagon to be a hexagon that satisfies La / L>1.15473. In addition, in the case of a hexagon that is elongated in the X direction, the vertex distance La is longer than the distances Lb and Lc between the other vertices. That is, the cracks of the present disclosure are hexagonal elongated in the X direction; in other words, the nanocrystalline alloy ribbon of the present disclosure has small pieces elongated in the X direction. As described above, the crack in one embodiment of the present disclosure has a shape in which elongated hexagons are combined in the X direction, and a pair of parallel sides are combined along the X direction.

[0017] Fig. 3 is a schematic diagram showing the form of a crack in another embodiment of the present disclosure. The crack form shown in Fig. 3 has an arc-shaped crack 8 around a pair of parallel sides 7 of a hexagon. In Fig. 3, the arc-shaped crack 8 is elliptical, but it may be partially missing, and may not be a uniform arc. In addition, there may be some sides 7 that do not have the arc-shaped crack 8.

[0018] Fig. 4 is a schematic diagram showing the form of a crack in yet another embodiment of the present disclosure. The form of the crack shown in Fig. 4 includes a crack 9 connecting vertices parallel to a pair of parallel sides 7 of a hexagon. In Fig. 4, the crack 9 connecting vertices parallel to a pair of parallel sides 7 is in a straight line, but it may be partially missing or in a broken line shape. In addition, there may be some vertices that do not include a crack 9 connecting vertices parallel to a pair of parallel sides 7.

[0019] In addition to the forms shown in Figs. 1 to 4, the cracks of the present disclosure may have the forms and further include other cracks.

[0020] The nanocrystalline alloy ribbon of the present disclosure can be produced by a production method including a step of rapidly cooling a molten alloy to obtain an amorphous alloy ribbon capable of nanocrystallization, and a heat treatment step of heat treating the amorphous alloy ribbon at a crystallization onset temperature or higher to form fine crystal grains.

[0021] The temperature of the heat treatment is set according to the alloy composition. The fine crystal grains are, for example, Fe with a body-centered cubic lattice structure in which Si and other elements are dissolved. The fine crystal grains can be analyzed using X-ray diffraction and a transmission electron microscope.

[0022] In the nanocrystalline alloy ribbon, at least 50% by volume of the nanocrystalline alloy ribbon is made up of fine crystal grains having an average grain size of 100 nm or less measured at the maximum dimension. The portion of the nanocrystalline alloy other than the fine crystal grains is mainly amorphous. The proportion of the fine crystal grains may be substantially 100% by volume.

[0023] The above-mentioned quenching can be performed by a single-roll method in which the molten alloy is discharged onto a rotating chill roll and rapidly solidified. The direction along the rotation direction of the chill roll is the casting direction of the nanocrystalline alloy ribbon. The casting direction of this nanocrystalline alloy ribbon is also the longitudinal direction of the nanocrystalline alloy ribbon, and the length can be, for example, 20,000 m.

[0024] An example of the alloy composition of the amorphous alloy ribbon capable of nanocrystallization is a composition represented by the following general formula. For example, by heat treating an amorphous alloy ribbon having a composition represented by the following general formula, a nanocrystalline alloy ribbon having a composition represented by the following general formula can be obtained. The nanocrystalline alloy ribbon preferably has a composition represented by the following general formula. General formula: (Fe 1-a Ma) 100-x-y-z-α-β-γ Cu x S y B z M' α M” β X γ (atom%)

[0025] In the above general formula, M is Co and / or Ni, M' is at least one element selected from the group consisting of Nb, Mo, Ta, Ti, Zr, Hf, V, Cr, Mn, and W, M" is at least one element selected from the group consisting of Al, platinum group elements, Sc, rare earth elements, Zn, Sn, and Re, X is at least one element selected from the group consisting of C, Ge, P, Ga, Sb, In, Be, and As, and a, x, y, z, α, β, and γ satisfy 0≦a≦0.5, 0.1≦x≦3, 0≦y≦30, 0≦z≦25, 5≦y+z≦30, 0≦α≦20, 0≦β≦20, and 0≦γ≦20, respectively. Preferably, in the above general formula, a, x, y, z, α, β, and γ are 0≦a≦0.1, 0.7≦x≦1.3, 12≦y≦17, 5≦z≦10, 1.5≦α≦5, 0≦β≦1, and 0≦γ≦1, respectively.

[0026] In the present disclosure, the nanocrystalline alloy ribbon will be described by taking as an example an Fe-Cu-Nb-Si-B based nanocrystalline alloy ribbon (FT-3 manufactured by Proterial Co., Ltd.).

[0027] In addition, as the nanocrystalline alloy ribbon of the present disclosure, it is preferable to use a nanocrystalline alloy ribbon obtained by subjecting an amorphous alloy ribbon capable of nanocrystallization to a heat treatment for nanocrystallization while applying tension thereto.

[0028] By applying tension to the amorphous alloy ribbon capable of nanocrystallization, it is possible to adjust the AC relative magnetic permeability μr of the nanocrystalline alloy ribbon. It is preferable to obtain a nanocrystalline alloy ribbon having an AC relative magnetic permeability μr of 100 to 2000 measured at a frequency of 128 kHz by this process.

[0029] One embodiment of the heat treatment method of the present disclosure will be described with reference to Fig. 5. Fig. 5 shows an in-line annealing device 150, which is an apparatus for performing an in-line annealing process in which a long amorphous alloy ribbon is subjected to a continuous heat treatment process including a temperature increase process and a temperature decrease (cooling) process from an unwinding roll to a winding roll to obtain a nanocrystalline alloy ribbon.

[0030] The in-line annealing device 150 includes an unwinding roller 112 (unwinding device) that unwinds the amorphous alloy ribbon 110 from a wound body 111 of an amorphous alloy ribbon (hereinafter also referred to as an alloy ribbon. Note that, for convenience, even when the alloy ribbon becomes a nanocrystalline alloy ribbon by heat treatment, it is referred to as an alloy ribbon.), a heating plate (heat transfer medium) 122 that heats the amorphous alloy ribbon 110 unwound from the unwinding roller 112, a cooling plate (heat transfer medium) 132 that cools the alloy ribbon 110 heated by the heating plate 122, and a winding roller 114 (winding device) that winds up the alloy ribbon 110 cooled by the cooling plate 132. In FIG. 5, the running direction of the alloy ribbon 110 is indicated by an arrow.

[0031] The heating plate 122 includes a first flat surface 122S on which the alloy ribbon 110 unwound from the unwinding roller 112 runs in contact with the first flat surface 122S. The heating plate 122 heats the alloy ribbon 110 running on the first flat surface 122S in contact with the first flat surface 122S via the first flat surface 122S. As a result, the running alloy ribbon 110 is stably and rapidly heated and nano-crystallized. The heating plate 122 is connected to a heat source (not shown) and is heated to a desired temperature by heat supplied from the heat source. Instead of being connected to a heat source, or in addition to being connected to a heat source, the heating plate 122 may include a heat source inside the heating plate 122 itself. Examples of the material for the heating plate 122 include stainless steel, Cu, a Cu alloy, and an Al alloy.

[0032] The heating plate 122 is housed in the heating chamber 120 . The heating chamber 120 may include a heat source separate from the heat source for the heating plate 122 to control the temperature of the heating chamber. The heating chamber 120 has openings (not shown) through which the alloy ribbon enters or exits, on both the upstream side and downstream side in the running direction of the alloy ribbon 110. The alloy ribbon 110 enters the heating chamber 120 through an entrance port which is an opening on the upstream side, and exits the heating chamber 120 through an exit port which is an opening on the downstream side.

[0033] The cooling plate 132 also includes a second flat surface 132S on which the alloy ribbon 110 travels while being in contact with the second flat surface 132S. The cooling plate 132 reduces the temperature of the alloy ribbon 110 traveling on the second flat surface 132S while being in contact with the second flat surface 132S via the second flat surface 132S. The cooling plate 132 may have a cooling mechanism (for example, a water-cooling mechanism), or may not have a particular cooling mechanism. The cooling plate 132 may be made of, for example, stainless steel, Cu, a Cu alloy, or an Al alloy. The cooling plate 132 is housed in the cooling chamber 130 .

[0034] The cooling chamber 130 may have a cooling mechanism (for example, a water-cooling mechanism), but may not have a particular cooling mechanism. That is, the cooling mode by the cooling chamber 130 may be water-cooling or air-cooling. The cooling chamber 130 has openings (not shown) through which the alloy ribbon enters or exits, on both the upstream side and downstream side in the running direction of the alloy ribbon 110. The alloy ribbon 110 enters the cooling chamber 130 through an entrance port which is an opening on the upstream side, and exits the cooling chamber 130 through an exit port which is an opening on the downstream side.

[0035] The winding roller 114 is provided with a rotation mechanism (for example, a motor) that rotates about its axis in the direction of the arrow Wr. By the rotation of the winding roller 114, the alloy ribbon 110 is wound at a desired speed.

[0036] The in-line annealing device 150 includes a guide roller 41, a dancer roller 60 (one of the tensile stress adjusting devices), a guide roller 42, and a pair of guide rollers 43 along the running path of the alloy ribbon 110 between the unwinding roller 112 and the heating chamber 120. The tensile stress is also adjusted by controlling the operation of the unwinding roller 112 and the take-up roller 114. The dancer roller 60 is provided so as to be movable in the vertical direction. By adjusting the vertical position of the dancer roller 60, the tensile stress of the alloy ribbon 110 can be adjusted. This allows the heat treatment for nanocrystallization to be performed while tension is being applied to the amorphous alloy ribbon.

[0037] The alloy ribbon 110 unwound from the unwinding roller 112 is guided into the heating chamber 120 via these guide rollers and dancer rollers. The in-line annealing device 150 includes a pair of guide rollers 44, 45 between the heating chamber 120 and the cooling chamber 130. The alloy ribbon 110 exiting the heating chamber 120 is guided into the cooling chamber 130 via these guide rollers.

[0038] The in-line annealing apparatus 150 is provided, between the cooling chamber 130 and the winding roller 114, with a pair of guide rollers 46, a guide roller 47, a dancer roller 62, a guide roller 48, a guide roller 49, and a guide roller 50 along the running path of the alloy ribbon 110. The dancer roller 62 is provided so as to be movable in the vertical direction. By adjusting the vertical position of the dancer roller 62, the tensile stress of the alloy ribbon 110 can be adjusted. The alloy ribbon 110 exiting the cooling chamber 130 is guided to the take-up roller 114 via these guide rollers and dancer rollers.

[0039] By using this in-line annealing device 150, a heat treatment is performed while applying tension in the casting direction of the amorphous alloy ribbon, and a nanocrystalline alloy ribbon can be produced.

[0040] In the present disclosure, the tension applied to the amorphous alloy ribbon in the casting direction is preferably 1.0 N to 50.0 N, more preferably 2.0 N to 40.0 N, and particularly preferably 3.0 N to 35.0 N. When the tension is 1.0 N or more, the magnetic permeability can be sufficiently reduced. When the tension is 50.0 N or less, breakage of the amorphous alloy ribbon or nanocrystalline alloy ribbon can be further suppressed.

[0041] In the heat treatment for nanocrystallization in this embodiment, the amorphous alloy ribbon is heated to an ultimate temperature equal to or higher than the crystallization temperature Tc1 (for example, 430°C or higher). This advances nanocrystallization in the structure of the alloy ribbon. The ultimate temperature is preferably 430°C to 640°C. When the attained temperature is 640°C or less (particularly when the B content is 10 atomic % or more and 20 atomic % or less), for example, the frequency of precipitation of Fe-B compounds that may deteriorate the soft magnetic properties (Hc, Bs, etc.) of the nanocrystalline alloy ribbon can be further reduced. It is also preferable that the set ultimate temperature and the temperature of the heat transfer medium are set to the same temperature.

[0042] The thickness of the amorphous alloy ribbon capable of nanocrystallization in this embodiment is preferably in the range of 10 μm to 50 μm. If it is less than 10 μm, the mechanical strength of the alloy ribbon itself is low, making it difficult to stably cast a long alloy ribbon. If it exceeds 50 μm, a part of the alloy is likely to crystallize, and the characteristics may deteriorate. The thickness of the amorphous alloy ribbon is more preferably 11 μm to 30 μm, and further preferably 12 μm to 27 μm.

[0043] The width of the amorphous alloy ribbon is not particularly limited, but is preferably 5 mm to 300 mm. When the width of the amorphous alloy ribbon is 5 mm or more, the manufacturing suitability of the amorphous alloy ribbon is excellent. When the width of the amorphous alloy ribbon is 300 mm or less, the uniformity of nanocrystallization is further improved in the process of obtaining a nanocrystalline alloy ribbon. The width of the amorphous alloy ribbon is preferably 200 mm or less.

[0044] The nanocrystalline alloy ribbon has a property of being more brittle than the amorphous alloy ribbon. Therefore, when a crack is formed in the nanocrystalline alloy ribbon by directly applying an external force, the crack can be formed with a small external force. In addition, the crack can be formed without substantially forming unevenness on the surface. Therefore, the flat surface state of the nanocrystalline alloy ribbon can be made good.

[0045] A cross-sectional view of an example in which an adhesive layer is disposed on one side of the nanocrystalline alloy ribbon having cracks formed therein according to the present disclosure is shown in Fig. 8. Fig. 8 shows a nanocrystalline alloy ribbon 20, an adhesive layer 10 attached to one side of the nanocrystalline alloy ribbon, and a resin sheet 15 attached to the adhesive layer 10. A crack 21 is formed in the nanocrystalline alloy ribbon 20, and the nanocrystalline alloy ribbon 20 is divided into small pieces 22. The adhesive layer 10 includes adhesives 12 on both sides of a support 11, the nanocrystalline alloy ribbon 20 is attached to one adhesive 12, and the resin sheet 15 is attached to the other adhesive 12.

[0046] The support 11 is a strip-shaped film member formed in an elongated shape, for example, a rectangular film member. The support 11 is formed using a flexible resin material. As the resin material, polyethylene terephthalate (PET) can be used.

[0047] For example, a pressure-sensitive adhesive can be used as the adhesive 12. For example, known adhesives such as acrylic adhesives, silicone adhesives, urethane adhesives, synthetic rubber, and natural rubber can be used as the adhesive 12. Acrylic adhesives are preferable as the adhesive 12 because they have excellent heat resistance and moisture resistance and can bond a wide range of materials.

[0048] It is preferable that the nanocrystalline alloy ribbon 20 and the adhesive layer 10 have shapes that satisfy the following relationship. 0.2mm≦(Width A-Width B)≦3mm The width A is a dimension related to the adhesive layer 10, and more preferably a dimension related to a region in the adhesive layer 10 where the adhesive 12 to which the nanocrystalline alloy ribbon 20 is adhered is provided. The width B is a dimension related to the nanocrystalline alloy ribbon 20. When the adhesive 12 is provided on the entire surface of the support 11 of the adhesive layer 10, the width A is a dimension related to the adhesive layer 10 or the support 11.

[0049] Here, the lower limit of (width A - width B) is preferably 0.5 mm, and more preferably 1.0 mm, and the upper limit of (width A - width B) is preferably 2.5 mm, and more preferably 2.0 mm.

[0050] In addition, the nanocrystalline alloy ribbons 20 and the adhesive layer 10 are preferably disposed so as to satisfy another relationship of the following formula. 0mm<gap a and 0mm<gap b

[0051] Gap a and gap b are the distances from the end of the adhesive layer 10 to the end of the nanocrystalline alloy ribbon 20. Specifically, gap a is the distance from the first adhesive layer end 10X of the adhesive layer 10 to the first ribbon end 20X of the nanocrystalline alloy ribbon 20. Gap b is the distance from the second adhesive layer end 10Y of the adhesive layer 10 to the second ribbon end 20Y of the nanocrystalline alloy ribbon 20.

[0052] The first ribbon end 20X is an end on the same side as the first adhesive layer end 10X of the nanocrystalline alloy ribbon 20. The second adhesive layer end 10Y is an end of the adhesive layer 10 opposite to the first adhesive layer end 10X. The second ribbon end 20Y is an end on the same side as the second adhesive layer end 10Y of the nanocrystalline alloy ribbon 20.

[0053] The width A, the width B, the gap a, and the gap b are dimensions in a direction intersecting, more preferably perpendicular to, the casting direction of the nanocrystalline alloy ribbon 20. The casting direction of the nanocrystalline alloy ribbon 20 and the extending direction of the adhesive layer 10 are the same direction. In addition, the casting direction of the nanocrystalline alloy ribbon 20 and the longitudinal direction of the nanocrystalline alloy ribbon 20 are the same direction.

[0054] A manufacturing method for forming cracks in the nanocrystalline alloy ribbon 20 according to the present disclosure will be described with reference to Fig. 6. Fig. 6 is a schematic diagram for explaining a manufacturing method for forming cracks in the nanocrystalline alloy ribbon 20 according to an embodiment.

[0055] 6 is mainly provided with a first unwinding roll 510, a first winding roll 520, a second unwinding roll 530, an attaching roll 540, a cracking roll 550, a flattening roll 560, and a third winding roll 570, from upstream to downstream in the manufacturing process. The manufacturing apparatus 500 may further be provided with a plurality of guide rolls 580. Note that the guide rolls 580 may be arranged at positions not shown as necessary.

[0056] FIG. 7 is a cross-sectional view illustrating the configuration of the laminate supplied from the first unwinding roll 510. As shown in FIG. 7, a laminate in which adhesive 12 is provided on each of first surface 11A and second surface 11B of adhesive layer 10 and resin sheet 15 is laminated on each surface is wound around first unwinding roll 510. Resin sheet 15 arranged on first surface 11A is a protective sheet, and resin sheet 15 arranged on second surface 11B is also referred to as a liner. Resin sheet 15 arranged on first surface 11A is a sheet having a smaller thickness than resin sheet 15 arranged on second surface 11B.

[0057] The resin sheet 15 arranged on the first surface 11A of the laminate unwound from the first unwinding roll 510 is peeled off. The peeled resin sheet 15 is taken up by the first winding roll 520, as shown in FIG.

[0058] The laminate from which the resin sheet 15 arranged on the first surface 11A has been peeled off is guided to the laminating roll 540 by a plurality of guide rolls 580. The nanocrystalline alloy ribbon 20 unwound from the second unwinding roll 530 is further guided to the laminating roll 540. No cracks 21 are formed in the nanocrystalline alloy ribbon 20 guided to the laminating roll 540.

[0059] The laminating roll 540 presses and adheres the nanocrystalline alloy ribbon 20 to the laminate from which the resin sheet 15 has been peeled off. Specifically, the laminate and the nanocrystalline alloy ribbon 20 are guided between two rolls arranged opposite to each other, and the nanocrystalline alloy ribbon 20 is pressed and adhered to the adhesive material 12 on the first surface 11A of the adhesive layer 10 by using the two rolls.

[0060] The nanocrystalline alloy ribbons 20 may be arranged so that their centers coincide with the adhesive layer 10 in the width direction, or may be arranged so that their centers are separated. In this case, they are arranged so as to satisfy the relationships of 0 mm<gap a and 0 mm<gap b (see FIG. 10). The laminate to which the nanocrystalline alloy ribbons 20 are adhered is led from the laminating roll 540 to the cracking roll 550, as shown in FIG. 6. This cracking roll 550 is composed of a cracking roll provided with protrusions (the cracking roll 55 of the present disclosure is used) and a roll not provided with protrusions.

[0061] The cracking roll 550 forms cracks 21 in the nanocrystalline alloy ribbon 20 bonded to the adhesive layer 10. Specifically, the laminate to which the nanocrystalline alloy ribbon 20 is bonded is guided between two rolls arranged opposite to each other, and one of the two rolls, a cracking roll having protrusions, is brought into direct contact with the nanocrystalline alloy ribbon 20 to form cracks 21 (see FIG. 8). Here, the protrusions of the cracking roll come into contact with the nanocrystalline alloy ribbon and apply pressure to form cracks.

[0062] Of the two rolls, the roll without the protrusions is disposed on the laminate side from which the resin sheet 15 has been peeled off. The nanocrystalline alloy ribbon 20 in which the cracks 21 have been formed contains a plurality of small pieces 22 (see FIG. 8 ). The plurality of small pieces 22 are adhered to the adhesive layer 10.

[0063] In the formation of cracks using the cracking roll 550, it is preferable to further form cracks that connect the plurality of cracks 21 in a network-like manner. Specifically, it is preferable to have a process of pressing the cracking roll 550 against the nanocrystalline alloy ribbon 20 to form the plurality of cracks 21, and then forming cracks that connect the plurality of cracks 21 in a network-like manner.

[0064] For example, after applying an external force directly to the nanocrystalline alloy ribbon 20 using the cracking roll 550 to form cracks 21, a second external force may be applied by bending or winding the nanocrystalline alloy ribbon 20 to form cracks that connect the multiple cracks 21 in a mesh-like pattern. The cracks that connect the cracks 21 (magnetic gaps that connect the cracks) are formed with the cracks 21 as starting points of brittle fracture and / or crack fracture.

[0065] The laminate guided from the cracking roll 550 to the flattening roll 560 is subjected to flattening treatment by the flattening roll 560. The flattening roll 560 is also referred to as a shaping roll.

[0066] Specifically, the laminate is guided between two rolls arranged opposite to each other in the flattening roll 560, and the laminate is sandwiched between the two rolls and pressed. This flattens the surface of the nanocrystalline alloy ribbon 20 on which the cracks 21 are formed.

[0067] A flattening process is performed, and cracks are formed in the nanocrystalline alloy ribbons 20, to obtain a sheet-shaped magnetic member 100 (see FIG. 8 ) having an adhesive layer 10 on one surface. The adhesive layer 10 has a resin sheet 15 on one surface. The sheet-shaped magnetic member 100 is guided to a third winding roll 570 via a guide roll 580. The sheet-shaped magnetic member 100 is wound around the third winding roll 570.

[0068] The structure of one embodiment of the cracking roll of the present disclosure will be described with reference to Figures 9 to 11. The cracking roll of the present disclosure is not limited to the one shown in the drawings, and can be modified as appropriate.

[0069] FIG. 10 is a front view (a) and a side view (b) of a ring-shaped member used in a cracking roll of the present disclosure. The ring-shaped member 1 of the present disclosure has a plurality of protrusions 2 on its outer peripheral surface. As shown in FIG. 11, the protrusions 2 have a triangular shape 5 extending in the axial direction of the ring-shaped member. Here, the protrusions 2 are formed from one end face to the other end face in the thickness direction of the ring-shaped member 1. The protrusions 2 have a linear tip extending in the axial direction of the ring-shaped member 1. Here, the term "linear" means that the tip shape may be arc-shaped or flat, or may be linear with width.

[0070] The ring-shaped member 1 contacts the nanocrystalline alloy ribbon and applies an external force directly to the nanocrystalline alloy ribbon. Although the nanocrystalline alloy ribbon has a brittle property, it has a high hardness, so the ring-shaped member 1 is preferably made of a wear-resistant tool steel material or a superhard material. For example, the tool steel material may be SS material, SC material, SKD material, or SKS material.

[0071] A side view of the cracking roll of the present disclosure is shown in Fig. 9. This cracking roll 55 is made by arranging a plurality of ring-shaped members 1, with spacer materials 4 disposed between the ring-shaped members 1. In Fig. 9, 28 ring-shaped members 1 are used. The spacer materials 4 used are ring-shaped. The spacer materials 4 need not be ring-shaped as long as they can set the intervals.

[0072] Here, two key grooves 3 are formed on the inner circumference of the ring-shaped member 1. The ring-shaped member 1 is attached to the shaft material of the cracking roll 55 by aligning the key grooves 3 with the engagement portion provided on the shaft material of the cracking roll. FIG. 2 shows the shaft portion 58. The shaft material to which the ring-shaped member 1 is attached can be inserted into the shaft portion 58 for use. The position of the key groove 3 is provided at a position that allows the position of the protrusion 2 of the ring-shaped member 1 to be adjusted. In other words, the position of the protrusion 2 can be made different when the ring-shaped member 1 is attached to the shaft material of the cracking roll using the first key groove 3 and when the ring-shaped member 1 is attached to the shaft material of the cracking roll using the second key groove 3. In other words, the protrusions can be shifted between adjacent ring-shaped members so that they are not continuous in the axial direction of the ring-shaped members. A third or fourth key groove 3 may be provided.

[0073] The cracking roll 55 of the present disclosure is configured so that the width in the axial direction matches the width of the nanocrystalline alloy ribbon. Then, while the cracking roll rotates, it continuously comes into contact with the nanocrystalline alloy ribbon in the casting direction, and forms cracks in the nanocrystalline alloy ribbon. At this time, the direction in which the cracking roll rotates is along the casting direction of the nanocrystalline alloy ribbon.

[0074] FIG. 14 shows how the protrusions of the cracking roll 55 of the present disclosure contact the nanocrystalline alloy ribbon. FIG. 14 shows the surface of the nanocrystalline alloy ribbon, and the cross bar 6 shows the state in which the tip of the protrusion of the cracking roll contacts the nanocrystalline alloy ribbon. That is, the cross bar 6 shows the shape in which the tip of the protrusion 2 of the ring-shaped member 1 contacts the nanocrystalline alloy ribbon 20. In the figure, S corresponds to the thickness of the spacer material. As shown in the arrangement of the cross bars 6, the shape in which the tip of the protrusion of the cracking roll contacts the nanocrystalline alloy ribbon 20 is a cross bar shape, and the cross bars 6 are spaced from each other to form a staggered shape. Here, the staggered shape can be expressed as rows of cross bars 6 arranged at intervals in the Y direction, arranged at intervals in the X direction, and the cross bars 6 are arranged alternately in the X direction.

[0075] According to the cracking roll of the present disclosure, the number of ring-shaped members 1 can be adjusted to match the width of the nanocrystalline alloy ribbon. Furthermore, the interval Px between the protrusions 2 of the ring-shaped member 1 can be adjusted by changing the width (S) of the spacer material 4. Here, the interval Px is the interval between the protrusions 2 in the nanocrystalline alloy ribbon in a direction perpendicular to the casting direction of the nanocrystalline alloy ribbon (X direction), and is the distance from the end of one protrusion to the end of the other protrusion. The interval Px corresponds to the distance between the vertices parallel to a pair of parallel sides 7 of the hexagon in the crack of the present disclosure. In addition, by preparing a plurality of ring-shaped members 1 with different intervals (circumferential intervals) between the protrusions 2 of the ring-shaped member 1, it is possible to adjust the interval Py between the protrusions 2 of the ring-shaped member 1. Here, the interval Py is the interval in the casting direction of the nanocrystalline alloy ribbon among the intervals between the protrusions in the nanocrystalline alloy ribbon, and is the center-to-center distance between one protrusion and the other protrusion.

[0076] The tips of the protrusions of the cracking roll come into contact with the nanocrystalline alloy ribbon and apply pressure to generate cracks. The cracks generated by the cracking roll and the network cracks generated during the subsequent transportation, etc., form the cracks shown in Figures 1 to 4.

[0077] The nanocrystalline alloy ribbon of the present disclosure is manufactured in a long shape in the casting direction (corresponding to the rotation direction of the cooling roll) by discharging the molten alloy onto a cooling roll and quenching it. In addition, the nanocrystalline alloy ribbon of the present disclosure is preferably heat-treated by applying tension in the casting direction. Due to these manufacturing methods, the nanocrystalline alloy ribbon of the present disclosure may have anisotropy in which the magnetic properties are different in the casting direction of the nanocrystalline alloy ribbon and in the direction perpendicular to the casting direction. Then, a nanocrystalline alloy ribbon having good magnetic properties in the casting direction may be obtained. When forming cracks in the nanocrystalline alloy ribbon having such anisotropic magnetic properties, it has been found that it is preferable to form the cracks so that elongated small pieces are formed in the direction perpendicular to the casting direction in order to obtain good properties as a sheet-like magnetic member. For this reason, in the present disclosure, the cracks are shaped so that elongated small pieces are obtained in the direction perpendicular to the casting direction of the nanocrystalline alloy ribbon.

[0078] In addition, as shown in Fig. 14, in the present disclosure, the tip of the protrusion of the cracking roll that contacts the nanocrystalline alloy ribbon is configured as a rod-like shape 6, and the horizontal rod 6 is configured to be staggered along the direction (X direction) perpendicular to the casting direction of the nanocrystalline alloy ribbon. It has been found that this makes it easy to form desired cracks. In other words, cracks that produce elongated pieces in the direction perpendicular to the casting direction of the nanocrystalline alloy ribbon are easily formed.

[0079] When the cracking roll of the present disclosure is used, the tips of the protrusions of the cracking roll come into contact with the nanocrystalline alloy ribbon in the state shown in FIG. 14 and press the nanocrystalline alloy ribbon. Then, staggered linear cracks corresponding to the rod shapes 6 are formed, and then cracks connecting the tips of the linear cracks are formed. As a result, the cracks become honeycomb-shaped with hexagons combined, and a pair of parallel sides of the hexagons are aligned in the direction (X direction) perpendicular to the casting direction of the nanocrystalline alloy ribbon. Then, elongated small pieces are obtained in the direction perpendicular to the casting direction of the nanocrystalline alloy ribbon.

[0080] In addition, according to the cracking roll of the present disclosure, when the rods 6 press the nanocrystalline alloy ribbon, an arc-shaped crack may be formed around the linear crack caused by the rods 6. An example of this arc-shaped crack is shown in FIG. Furthermore, with the cracking roll of the present disclosure, cracks may be formed that connect the vertices parallel to a pair of parallel sides of a hexagon, as shown in FIG.

[0081] According to the cracking roll of the present disclosure, the number of steps required to manufacture the cracking roll can be reduced, for example, compared to the case where honeycomb-structured protrusions are formed on the entire outer peripheral surface of a cylindrical (columnar) cracking roll. In addition, it is easy to reconfigure the cracking roll in response to changes in the cracks to be formed. Therefore, the cracking roll of the present disclosure is advantageous in reducing the number of steps required to manufacture the sheet-shaped magnetic member.

[0082] Fig. 8 is a schematic diagram of a sheet-shaped magnetic member obtained by the manufacturing method of Fig. 6. The sheet-shaped magnetic member 100 shown in Fig. 8 includes nanocrystalline alloy ribbons having cracks formed therein, and an adhesive layer is provided on one surface of the nanocrystalline alloy ribbons. The resin sheet 15 attached to the adhesive layer 10 is peeled off and attached to nanocrystalline alloy ribbons 20 of another sheet-shaped magnetic member 100, thereby producing a sheet-shaped magnetic member in which nanocrystalline alloy ribbons are stacked.

[0083] FIG. 12 is a schematic diagram illustrating an embodiment of a method for producing a sheet-shaped magnetic member 300 in which nanocrystalline alloy ribbons 20 having cracks formed therein are stacked. The sheet-shaped magnetic member 300 in which the nanocrystalline alloy ribbons 20 having cracks are stacked can be manufactured by using a manufacturing apparatus 600 shown in Fig. 12. Fig. 12 shows the manufacturing apparatus 600 for manufacturing the sheet-shaped magnetic member 300 including five layers of the nanocrystalline alloy ribbons 20.

[0084] The manufacturing apparatus 600 is mainly provided with a supply roll 601, a resin sheet winding roll 602, a first magnetic sheet unwinding roll 611, a first winding roll 612, a first pasting roll 613, a second magnetic sheet unwinding roll 621, a second winding roll 622, a second pasting roll 623, a third magnetic sheet unwinding roll 631, a third winding roll 632, a third pasting roll 633, a fourth magnetic sheet unwinding roll 641, a fourth winding roll 642, a fourth pasting roll 643, a fifth magnetic sheet unwinding roll 651, a fifth pasting roll 653, a flattening roll 663, and a multilayer magnetic sheet winding roll 670, from the upstream to the downstream of the manufacturing process. The manufacturing apparatus 600 may further be provided with a plurality of guide rolls 680. The guide roll 680 may be arranged at a position not shown as necessary.

[0085] The manufacturing apparatus 600 may manufacture the sheet-shaped magnetic member 300 having two or more and four or less layers of nanocrystalline alloy ribbons 20. Also, the sheet-shaped magnetic member 300 may be manufactured having six or more layers of nanocrystalline alloy ribbons 20. In this case, the number of the above-mentioned first magnetic sheet unwinding rolls 611, etc. is changed according to the number of nanocrystalline alloy ribbons 20. Also, instead of the sheet-shaped magnetic member 100 unwound from the first magnetic sheet unwinding roll 611, etc., a sheet-shaped magnetic member having multiple layers of nanocrystalline alloy ribbons can be unwound to form a multilayer structure.

[0086] There is no particular upper limit on the number of layers. The number of layers may be determined as appropriate. However, when winding the sheet-shaped magnetic member 300 in which the nanocrystalline alloy ribbons 20 are laminated, if the number of layers is large, it may be difficult to wind the sheet-shaped magnetic member 300 or the sheet-shaped magnetic member 300 in which the nanocrystalline alloy ribbons 20 are laminated may cause a defective shape during winding. Therefore, when winding the sheet-shaped magnetic member 300 in which the nanocrystalline alloy ribbons 20 are laminated, the number of layers is preferably 30 or less. More preferably, it is 25 or less, more preferably 20 or less, more preferably 15 or less, and more preferably 10 or less.

[0087] As shown in FIG. 7, a laminate in which a resin sheet 15 is laminated on a first surface 11A and a second surface 11B of an adhesive layer 10 is wound around the supply roll 601. The resin sheet 15 arranged on the first surface 11A of the laminate unwound from the supply roll 601 is peeled off. The peeled resin sheet 15 is taken up by a resin sheet take-up roll 602, as shown in FIG.

[0088] The laminate from which the resin sheet 15 arranged on the first surface 11A has been peeled off is guided to a first laminating roll 613 by a guide roll 680. The sheet-shaped magnetic member 100 unwound from a first magnetic sheet unwinding roll 611 is further guided to the first laminating roll 613.

[0089] The first laminating roll 613 presses and adheres the sheet-shaped magnetic member 100 to the laminate from which the resin sheet 15 has been peeled off. Specifically, the laminate and the sheet-shaped magnetic member 100 are guided between two rolls arranged opposite to each other, and the two rolls are used to press and adhere the nanocrystalline alloy ribbons 20 of the sheet-shaped magnetic member 100 to the first surface 11A of the adhesive layer 10 of the laminate.

[0090] The resin sheet 15 of the sheet-shaped magnetic member 100 adhered by the first laminating roll 613 is peeled off from the sheet-shaped magnetic member 100 and taken up by the first winding roll 612. The laminate after the resin sheet 15 is taken up by the first winding roll 612 is guided to the second laminating roll 623. The sheet-shaped magnetic member 100 unwound from the second magnetic sheet unwinding roll 621 is further guided to the second laminating roll 623.

[0091] The second laminating roll 623 presses and adheres the sheet-shaped magnetic member 100 onto the laminate delivered from the first laminating roll 613. Specifically, the laminate and the sheet-shaped magnetic member 100 are led between two rolls arranged opposite to each other, and the nanocrystalline alloy ribbons 20 of the sheet-shaped magnetic member 100 are pressed and adhered onto the second surface 11B of the adhesive layer 10 of the laminate by using the two rolls.

[0092] The resin sheet 15 of the sheet-shaped magnetic member 100 adhered by the second laminating roll 623 is peeled off from the sheet-shaped magnetic member 100 and taken up by the second winding roll 622. The laminate after the resin sheet 15 has been taken up by the second winding roll 622 is guided to a third laminating roll 633. The sheet-shaped magnetic member 100 unwound from a third magnetic sheet unwinding roll 631 is further guided to the third laminating roll 633.

[0093] Similarly, the third laminating roll 633, the fourth laminating roll 643, and the fifth laminating roll 653 are used to laminate the nanocrystalline alloy ribbons into five layers. The laminate guided from the fifth laminating roll 653 to the flattening roll 663 is subjected to flattening treatment by the flattening roll 663 .

[0094] The nanocrystalline alloy ribbons 20 and the adhesive layer 10 are preferably arranged so as to satisfy the relationships of 0 mm<gap a and 0 mm<gap b (see FIG. 8). However, in the lamination process of the sheet-shaped magnetic member 100 and the laminate, a positional deviation may occur. When this positional deviation occurs, the relationship between the nanocrystalline alloy ribbons 20 and the adhesive layer 10 may have a negative gap a, for example. In other words, an end of the nanocrystalline alloy ribbon 20 may protrude from an end of the adhesive layer 10 on one side of the nanocrystalline alloy ribbon 20. Even if an end of the nanocrystalline alloy ribbon 20 protrudes beyond the end of the adhesive layer 10 on one side of the nanocrystalline alloy ribbon 20, the nanocrystalline alloy ribbon 20 can maintain its adherence to the adhesive layer 10 as long as the relationship between the nanocrystalline alloy ribbon 20 and the adhesive layer 10 on the other side of the nanocrystalline alloy ribbon 20 satisfies the relationship 0 mm<gap a and 0 mm<gap b (see Figure 8).

[0095] The sheet-shaped magnetic member 300 is guided to the multilayered magnetic sheet take-up roll 670 via a guide roll 680. The sheet-shaped magnetic member 300 is taken up by the multilayered magnetic sheet take-up roll 670. Note that, other than the method of taking up the sheet-shaped magnetic member 300 by the multilayered magnetic sheet take-up roll 670, the sheet-shaped magnetic member 300 may be cut to a required length.

[0096] The laminate after the flattening process becomes the sheet-shaped magnetic member 300 shown in Fig. 13. The sheet-shaped magnetic member 300 shown in Fig. 13 is formed by laminating nanocrystalline alloy ribbons 20 via adhesive layers 10, and includes resin sheets 15 as the bottom and top layers. The sheet-shaped magnetic member 300 is a laminate of five layers of nanocrystalline alloy ribbons 20. The number of layers of nanocrystalline alloy ribbons 20 in the sheet-shaped magnetic member 300 can be set as appropriate.

[0097] For example, a sheet-shaped magnetic member having a plurality of five layers as shown in Fig. 13 may be produced, and the five-layer sheet-shaped magnetic members may be stacked to produce a sheet-shaped magnetic member having a large number of stacked nanocrystalline alloy ribbons 20. Moreover, a sheet-shaped magnetic member having a larger area may be produced by arranging the sheet-shaped magnetic members side by side.

[0098] In the sheet-shaped magnetic member of the present disclosure, the number of layers of the nanocrystalline alloy ribbons 20 is preferably 10 or more. More preferably, the number is 15 or more, more preferably 20 or more, and even more preferably 25 or more. There is no particular need to set an upper limit, and the required number of layers may be stacked.

[0099] The sheet-like magnetic member of the present disclosure may have another magnetic material, a metal foil such as aluminum, a resin sheet, or the like attached to the bottom or top layer.

[0100] The sheet-shaped magnetic member of the present disclosure can be formed into a desired size and stacked in the required number to form a magnetic sheet or core material for contactless charging.

[0101] Example 1 [Manufacturing of nanocrystalline alloy ribbons] Using a manufacturing apparatus having the components shown in FIG. 5, a heat treatment was performed while applying tension to an amorphous alloy ribbon (Fe-Cu-Nb-Si-B alloy) to produce a nanocrystalline alloy ribbon (Fe-Cu-Nb-Si-B alloy). The tension applied to the amorphous gold ribbon was 40 MPa. The temperature reached by the amorphous alloy ribbon in the heat treatment was 640°C. The thickness of the nanocrystalline alloy ribbon was 16 μm and the width was 30 mm. The nanocrystalline alloy ribbon in the example is equivalent to FT-3 manufactured by Proterial Co., Ltd. [Cracking Roll] A link-shaped member 1 having the structure shown in Fig. 10 and Fig. 11 was prepared. The ring-shaped member 1 had an outer diameter of 31 mm and a thickness of 0.8 mm, and was made of SKD tool steel. Next, as shown in Fig. 9, a cracking roll was produced by arranging a plurality of ring-shaped members 1 with a spacer material 4 having a thickness of 0.6 mm sandwiched therebetween. At this time, the ring-shaped members 1 were attached so that the protrusions of adjacent ring-shaped members 1 were shifted by half a pitch with respect to the circumferential pitch of the protrusions so that they were not aligned in a straight line in the axial direction. The thickness of the spacer material is preferably 0.4 mm or more and 2 mm or less.

[0102] Fig. 14 is a schematic diagram showing the state of the contact area when this cracking roll comes into contact with the nanocrystalline alloy ribbon 20. Fig. 14 shows the surface of the nanocrystalline alloy ribbon, and the cross bar 6 shows the state in which the tip of the protrusion of the cracking roll comes into contact with the nanocrystalline alloy ribbon. In other words, the cross bar 6 shows the shape in which the tip of the protrusion 2 of the ring-shaped member 1 comes into contact with the nanocrystalline alloy ribbon 20. In the figure, S corresponds to the thickness of the spacer material.

[0103] In this embodiment, the horizontal bars 6 face in one direction. This one direction is defined as the X direction. The X direction is a direction perpendicular to the casting direction of the nanocrystalline alloy ribbon 20. The interval Px between the horizontal bars 6 in the X direction is 2 mm. In other words, among the intervals between the protrusions in the nanocrystalline alloy ribbon, the interval Px in the direction perpendicular to the casting direction of the nanocrystalline alloy ribbon is 2 mm.

[0104] In addition, the Y direction in the figure is the casting direction of the nanocrystalline alloy ribbon 20. In the Y direction, the interval Py between the horizontal bars 6 is set to 1.6 mm. In other words, among the intervals between the protrusions in the nanocrystalline alloy ribbon, the interval Py in the casting direction of the nanocrystalline alloy ribbon is 1.6 mm. The interval between the horizontal bars 7 in the Y direction is preferably 1 mm or more and 2 mm or less. As will be described later, this embodiment is configured to form a crack having an elongated shape in the X direction, and has a relationship of distance Px>distance Py.

[0105] [Manufacturing of sheet-shaped magnetic members] Using the above cracking roll, a sheet-shaped magnetic member 100 shown in Fig. 8 was produced by the production method shown in Fig. 6. The state of cracks in the nanocrystalline alloy ribbons 20 of the produced sheet-shaped magnetic member 100 was observed. For the observation, a USB camera L-836 (magnification 20) manufactured by Hozan Corporation and a stereo microscope SZ2-ILST (magnification 10 to 40) manufactured by Olympus Corporation were used. In addition, the observation was performed by transmitting light from the back side of the observation surface.

[0106] Fig. 15 shows an observation photograph (observation A). Fig. 16 shows a copy of the crack lines in the observation photograph of Fig. 15. Fig. 16 is a copy of an area of ​​15 mm (X direction) x 11 mm (Y direction) of the nanocrystalline alloy ribbon in Fig. 15. As can be seen from Figs. 15 and 16, the small piece in this example has an elongated shape in the horizontal direction (X direction). Here, the X direction is a direction perpendicular to the casting direction of the nanocrystalline alloy ribbon, and the Y direction is the casting direction of the nanocrystalline alloy ribbon.

[0107] Since cracks are easily formed in the nanocrystalline alloy ribbon, the cracks are not uniform. However, the cracks of the present disclosure have a basic shape of a hexagon that is elongated in the X direction, and are combined to form a honeycomb shape. A pair of parallel sides of the hexagon are aligned along the X direction. The hexagon is elongated in the X direction. Many arc-shaped cracks are formed around the pair of parallel sides of the hexagon. The hexagon is partially provided with a crack that connects vertices that are parallel to the pair of parallel sides.

[0108] The particle size was measured using Figures 15 and 16. An example of a small piece is shown in Figure 17. The maximum value of the small piece in the Y direction is length L, and the maximum value of the small piece in the X direction is length W. At this time, small pieces PW were defined as pieces with length W > length L and length W being 0.2 mm or more, and small pieces PL were defined as pieces with length W ≦ length L and length L being 0.2 mm or more, and the number of each was calculated. The number PWN of small pieces PW was 450, and the number PLN of small pieces PL was 100. As a result, PWN / (PWN+PLN)=82%. This PWN / (PWN+PLN) is preferably 60% or more. It is preferable that it is 70% or more, and more preferably 80% or more. The maximum value of the length W was 6.8 mm. The length W is preferably 10 mm or less, more preferably 8 mm or less, and further preferably 7 mm or less.

[0109] Furthermore, the number PWMN of small pieces where length W > length L and length W was 1.6 mm or more was 44. This number PWMN is preferably 10 or more. Furthermore, 20 or more is preferable, and 30 or more is more preferable. Furthermore, PWMN / PWN was 10%. This PWMN / PWN is preferably 5% or more.

[0110] If the small pieces are regular hexagons, the ratio of length W to length L is length W / length L = 1.15473. Therefore, small pieces with length W / length L greater than 1.15473 can be regarded as hexagonal pieces elongated in the X direction rather than regular hexagons. The number PWD of small pieces with length W / length L > 1.15473 among the small pieces PW was 403. This was 90% (PWD / PWN) of PWN. Therefore, according to the present disclosure, it was found that there are many small pieces corresponding to hexagons elongated in the X direction. In other words, among the three vertices (diagonals) of a hexagon, the vertex distance La parallel to the X direction can be regarded as longer than the distances Lb and Lc between the other vertices. This ratio (PWD / PWN) is preferably 80% or more, and more preferably 85% or more.

[0111] In addition, the number PWT of small pieces with length W / length L>2, where length W is more than twice length L, was 182. The number PWT of small pieces that are elongated in the X direction, where length W is more than twice length L, was 33.1% of PWN+PLN=550. It is preferable that the ratio (PWT / (PWN+PLN)) of small pieces with length W more than twice length L, where L / W>2, is 20% or more. More preferably, it is 25% or more, and more preferably, it is 30% or more.

[0112] FIG. 23 shows an observation photograph of another region (observation B). Observation B was observed in the same manner as observation A. FIG. 24 shows a copy of the crack lines in the observation photograph of FIG. 23. FIG. 24 is a copy of an area of ​​15 mm (X direction) × 11 mm (Y direction) of the nanocrystalline alloy ribbon in FIG. 23. As can be seen from FIGS. 23 and 24, the small pieces of this example have an elongated shape in the horizontal direction (X direction). Here, the X direction is a direction perpendicular to the casting direction of the nanocrystalline alloy ribbon, and the Y direction is the casting direction of the nanocrystalline alloy ribbon. The size of the small pieces was measured using these figures 23 and 24. The measurement was the same as above. The results are shown in Tables 1 and 2 together with Observation A.

[0113] [Table 1]

[0114] [Table 2]

[0115] A sheet-like magnetic member 300 having five layers of nanocrystalline alloy ribbons 20 was produced by the manufacturing method shown in FIG. 12 using the sheet-like magnetic member 100 including the nanocrystalline alloy ribbons having the cracks formed therein according to the present disclosure. Furthermore, five of these sheet-like magnetic members 300 were stacked to produce a sheet-like magnetic member having 25 layers of nanocrystalline alloy ribbons 20. A side view of a sheet-like magnetic member 700 having 25 layers of nanocrystalline alloy ribbons is shown in FIG. 22. In this sheet-like magnetic member 700, three sheet-like magnetic members 300 were arranged in parallel, two sheet-like magnetic members 300 were arranged in parallel on top of them with a half pitch shift in the width direction, and three sheet-like magnetic members 300 were arranged in parallel on top of them in the same manner as the first layer, and five were stacked in the stacking direction in the same manner. The length direction was about 60 mm. When the sheet-like magnetic members 300 are bonded to each other, the resin sheet 15 on the bonding surface is peeled off to expose the adhesive layer 20, and the nanocrystalline alloy ribbons 20 are laminated. In the bottom layer, a base material (such as a resin sheet) of a desired size may be provided, and the sheet-like magnetic members 300 may be arranged and bonded thereon. In addition, a resin sheet of a desired size may be provided in the top layer. In this 25-layer sheet-like magnetic member 700, two adhesive layers 10 are provided between five of the sheet-like magnetic members 300.

[0116] The characteristics of the 25-layer sheet-shaped magnetic member 700 of this example were evaluated. As a comparative example, a sheet-shaped magnetic member in which no cracks were formed and 25 layers were laminated with adhesive layers interposed therebetween was used. The measuring device 800 used in the evaluation will be described with reference to Fig. 21. Fig. 21 is a diagram illustrating the measuring device 800 used in the evaluation of the magnetic sheet.

[0117] The measuring device 800 is provided with an LCR meter 810, a measuring coil 820, and an aluminum board 830. The LCR meter 810 is connected to the measuring coil 820, and is a device that measures Ls (inductance (H)) and Rs (resistance (Ω)) of the sheet-shaped magnetic member 840 together with the measuring coil 820. The LCR meter 810 used was an E4980A manufactured by Keysight Corporation. Note that the sheet-shaped magnetic member 700 of the present disclosure and a sheet-shaped magnetic member of a comparative example were arranged as the sheet-shaped magnetic member 840 and evaluated.

[0118] The measuring coil 820 is a coil disposed together with the aluminum board 830, sandwiching the sheet-like magnetic member 840 therebetween. The diameter of the measuring coil is 50 mm. At a frequency of 85 kHz, the measuring coil 820 has an Ls of 3.5 μH and an Rs of 28 mΩ.

[0119] The aluminum board 830 is a plate member formed in a rectangular shape. Specifically, the aluminum board 830 is a plate member having a square shape with each side measuring 60 mm and a thickness of 2 mm.

[0120] Furthermore, Q is calculated based on Ls and Rs measured by the measuring device 800. The calculation is performed using the formula Q=Ls / Rs×2πf, where f is the frequency (Hz).

[0121] Next, the measurement results by the measurement device 800 will be described with reference to Fig. 18 to Fig. 20. Fig. 18 is a graph showing the value of Q calculated based on the measurement results. Fig. 19 is a graph showing the measured value of Ls. Fig. 20 is a graph showing the measured value of Rs.

[0122] In Fig. 18 to Fig. 20, the embodiment is indicated by Crack 25L, and the comparative example is indicated by Non crack 25L. In Fig. 18, the horizontal axis indicates the frequency (kHz) used in the measurement, and the vertical axis indicates the Q value. In Fig. 19, the horizontal axis indicates the frequency (kHz) used in the measurement, and the vertical axis indicates the Ls (H) value. In Fig. 20, the horizontal axis indicates the frequency (kHz) used in the measurement, and the vertical axis indicates the Rs (Ω) value.

[0123] 18, the Q value of the embodiment is higher than that of the comparative example at almost all frequencies. In other words, the Q value of the embodiment is larger than that of the comparative example at almost all frequencies.

[0124] The operating frequency used in a contactless charging circuit for an automobile is about 85 kHz, and the operating frequency used in a contactless charging circuit for a smartphone is about 128 kHz or 360 kHz. In other words, the sheet-like magnetic member of the embodiment is shown to have a high Q value at the operating frequencies used in a contactless charging circuit for an automobile or a contactless charging circuit for a smartphone. Therefore, the sheet-like magnetic member is useful for these applications.

[0125] As shown in FIG. 19, the Ls value decreases as the frequency increases. There was no significant difference between the Example and the Comparative Example. As shown in FIG. 20, the Rs value increases as the frequency increases overall. In high-frequency regions, the increase in Rs with increasing frequency is greater than in low-frequency regions. The higher the frequency region, the lower the Example is located compared to the Comparative Example. In other words, the Example has a smaller Rs value than the Comparative Example at frequencies above about 100 kHz. In the Example, Rs is small, and the Q value is improved by suppressing eddy current loss.

[0126] Since the cracking roll of the present disclosure can be manufactured by arranging ring-shaped members, it is easily understood that the shape of the crack in the nanocrystalline alloy ribbon 20 can be adjusted by adjusting the spacing between the ring-shaped members or changing the shape of the protrusions of the ring-shaped members. According to the present disclosure, it is possible to obtain a sheet-shaped magnetic member formed by stacking nanocrystalline alloy ribbons in which cracks of an appropriate shape are formed. Furthermore, the sheet-shaped magnetic member of the present disclosure can be used as a magnetic sheet (for example, a magnetic sheet for contactless charging) or as a core material for inductance components.

Claims

1. a sheet-like magnetic member in which nanocrystalline alloy ribbons are laminated, An adhesive layer is provided between the nanocrystalline alloy ribbons, The nanocrystalline alloy ribbon is cracked and divided into small pieces. The cracks are in a honeycomb shape formed by combining hexagons, A sheet-shaped magnetic member, wherein a pair of parallel sides of the hexagon are aligned along a direction (X direction) perpendicular to the casting direction of the nanocrystalline alloy ribbon.

2. The sheet-shaped magnetic member according to claim 1 , wherein the hexagon has arc-shaped cracks around the pair of parallel sides.

3. The sheet-shaped magnetic member according to claim 1 , wherein the hexagon has cracks connecting vertices parallel to the pair of parallel sides.

4. The casting direction of the nanocrystalline alloy ribbon is defined as a Y direction, and the direction perpendicular to the casting direction is defined as an X direction. The maximum length of the small piece in the Y direction is defined as length L, and the maximum length of the small piece in the X direction is defined as length W, A small piece PW is a piece with length W>length L and length W being 0.2 mm or more, and a small piece PL is a piece with length W≦length L and length L being 0.2 mm or more, When the nanocrystalline alloy ribbon was observed in an area of ​​15 mm (X direction) × 11 mm (Y direction), 2. The sheet-shaped magnetic member according to claim 1, wherein a relationship between the number PWN of the small pieces PW and the number PLN of the small pieces PL satisfies PWN / (PWN+PLN)≧60%.

5. 5. The sheet-like magnetic member according to claim 4, wherein a ratio (PWD / PWN) of the number PWD of the pieces PW that satisfy length W / length L>1.15473 to the number PWN of the pieces PW is 80% or more.

6. 5. The sheet-shaped magnetic member according to claim 4, wherein length W>length L and the number PWMN of small pieces each having a length W of 1.6 mm or more is 10 or more.

7. The molten alloy is discharged onto a rotating cooling roll and quenched to produce an amorphous alloy ribbon; The amorphous alloy ribbon is subjected to a heat treatment to produce a nanocrystalline alloy ribbon; forming an adhesive layer on one surface of the nanocrystalline alloy ribbon, and directly applying a cracking roll to a surface of the nanocrystalline alloy ribbon opposite to the surface on which the adhesive layer is formed, to form cracks in the nanocrystalline alloy ribbon; A method for producing a sheet-shaped magnetic member, comprising the steps of: preparing a plurality of nanocrystalline alloy ribbons having the cracks formed therein; and laminating the plurality of nanocrystalline alloy ribbons via the adhesive layer, The heat treatment is performed in a state where tension is applied to the amorphous alloy ribbon in a casting direction, The cracks are in the form of a combination of hexagons, A method for manufacturing a sheet-shaped magnetic member, wherein a pair of parallel sides of the hexagon are aligned along a direction (X direction) perpendicular to the casting direction of the nanocrystalline alloy ribbon.

8. The method for manufacturing a sheet-shaped magnetic component as described in claim 7, wherein the cracking roll has a plurality of protrusions on its surface, the portion of the protrusions that contact the nanocrystalline alloy ribbon is linear along a direction perpendicular to the casting direction of the nanocrystalline alloy ribbon, and the linear protrusions are arranged in a staggered pattern.

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