Magnetic sheet

Abstract

Provided is a magnetic sheet in which a plurality of alloy thin strips in which a plurality of linear cracks are regularly formed are stacked via an adhesive layer, the linear cracks being aligned in a first direction and being arranged at a distance apart in the first direction and a direction orthogonal to the first direction. The magnetic sheet of the present invention has a small temporal change in magnetic properties.

Description

[0001] This application is a divisional application of Chinese patent application No. 202080031374.3, filed on May 21, 2020, entitled "Method and Apparatus for Manufacturing Alloy Strip Laminates". Technical Field

[0002] This disclosure relates to a method for manufacturing alloy strip laminates and an apparatus for manufacturing alloy strip laminates. Background Technology

[0003] In recent years, electronic devices such as smartphones, tablet computers, and mobile phones have become increasingly widespread. Especially mobile phones (e.g., smartphones), web terminals, and music players, which require long-term continuous use for portability, utilize secondary batteries such as lithium-ion batteries as their power source. Charging methods for these secondary batteries include: contact charging, where the electrodes on the power receiving side directly contact the electrodes on the power supply side; and contactless charging, where transmission coils are placed on both the power supply and power receiving sides, and charging is achieved through electromagnetic induction. Contactless charging eliminates the need for electrodes to directly contact the power supply and power receiving devices, allowing the same power supply to charge different power receiving devices. Furthermore, contactless charging is a technology applicable not only to portable devices but also to other electronic devices, electric vehicles, drones, and more.

[0004] In contactless charging, the magnetic flux generated in the primary transmission coil of the power supply device induces 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. To achieve high power transmission efficiency, a magnetic sheet serving as a coil yoke is provided on the opposite side of the contact surface with the power supply device and the power receiving device for the transmission coil. This magnetic sheet has the following function.

[0005] The primary function is as a magnetic shielding material. For example, if the leakage magnetic flux generated during the charging operation of a contactless charging device flows through other components, such as the metal parts constituting the secondary battery, these components will generate heat due to eddy currents. The magnetic sheet can act as a magnetic shielding material to suppress this heat generation.

[0006] The second function of the magnetic sheet is to act as a yoke component that allows the magnetic flux generated in the coil during charging to flow back.

[0007] Previously, the mainstream soft magnetic material used in the magnetic sheets of contactless charging devices was ferrite. Recently, as shown in Japanese Patent Application Publication No. 2008-112830, alloy strips made of soft magnetic materials including amorphous alloys and nanocrystalline alloys have also begun to be used.

[0008] Japanese Patent Application Publication No. 2008-112830 discloses a method for manufacturing a magnetic sheet, comprising a step of forming a magnetic sheet by bonding a thin plate-shaped magnetic body (alloy strip) to a sheet substrate through an adhesive layer, and a step of maintaining the alloy strip in a bonded state on the sheet substrate and dividing it into multiple pieces by external force to improve the Q value or reduce eddy current loss. Furthermore, Japanese Patent Application Publication No. 2008-112830 discloses that by dividing the alloy strip into multiple pieces by applying external force, the Q value can be improved when the magnetic sheet is used as a magnetic body for, for example, a sensor. Furthermore, Japanese Patent Application Publication No. 2008-112830 discloses that when the magnetic sheet is used as a magnetic body for magnetic shielding, the current path of the alloy strip can be blocked, reducing eddy current loss. Further, Japanese Patent Application Publication No. 2008-112830 discloses that when the alloy strip is divided into multiple pieces, the area of ​​the divided magnetic sheet is preferably 0.01 mm². 2 The above 25mm 2 The following range.

[0009] Furthermore, Japanese Patent Publication No. 2015-505166 discloses, as an example, a method for manufacturing a magnetic sheet, the following two steps are disclosed: 1) attaching a protective film to both sides of a thin-film magnetic sheet (alloy strip) composed of at least one layer of amorphous strip and forming a release film on the exposed surface of a double-sided adhesive tape to form a laminate; and 2) slicing the laminate to divide the alloy strip into multiple thin slices.

[0010] Furthermore, as a further follow-up step, the following step is disclosed: 3) Further laminating the above-mentioned sliced ​​laminated sheet, while planarizing and thinning the laminated sheet, filling the gaps between the above-mentioned protective film and the first and second adhesive layers of the double-sided tape into the gaps of the above-mentioned multiple thin sheets to achieve insulation. The planarization and thinning of the sheet are achieved through the above-mentioned step 3). Summary of the Invention

[0011] The problem that the invention aims to solve

[0012] When using magnetic sheets made of multiple segmented alloy strips for contactless charging devices, permeability is often used as a substitute for magnetic properties to quantify the segmentation state. Typically, a magnetic sheet with a relative permeability μr of 100 to 2000 at 128kHz AC is desirable. To produce a magnetic sheet with this permeability value, it is necessary to finely segment the alloy strips at intervals of approximately 1 mm.

[0013] However, in cases where the internal alloy strip is finely divided into multiple segments by applying external force through a resin film, as described in Japanese Patent Application Publication No. 2015-505166, the resin film of the magnetic sheet has high elasticity, making it impossible to finely divide the alloy strip when the applied external force is small. On the other hand, if the applied external force is large enough to finely divide the alloy strip, unevenness will remain on the surface of the resin film and the alloy strip. In this case, the elasticity of the resin film in the magnetic sheet causes deformation of the unevenness of the alloy strip or changes in the spacing between the multiple segments, resulting in a slow change in the AC relative permeability μr over time. Therefore, the AC relative permeability μr will differ during mass production and after the magnetic sheet is assembled into an electronic device. As a result, problems arise where the characteristics of the electronic device cannot be fully obtained.

[0014] Therefore, the problem to be solved by the invention is to provide a method for manufacturing an alloy strip laminate that can achieve at least one of the following: reducing the magnitude of the external force that divides the alloy strip into multiple parts, ensuring good planarity of the divided alloy strip, and suppressing the time-dependent changes in magnetic properties, as well as an apparatus for manufacturing the alloy strip laminate.

[0015] It should be noted that this alloy strip laminate can be used, for example, for magnetic sheets. However, the alloy strip laminate is not limited to magnetic sheets, and can also be used for other applications as a laminate of alloy strips with cracks.

[0016] Methods for solving problems

[0017] The specific methods used to solve the above problems include the following approaches.

[0018] <1> A method for manufacturing an alloy strip laminate includes: a step of forming cracks in the alloy strip by directly applying an external force to the alloy strip of a first laminate member having an adhesive layer and an alloy strip, thereby obtaining a first laminate having the adhesive layer and the alloy strip with the cracks formed therein; a step of forming cracks in the alloy strip by directly applying an external force to the alloy strip of a second laminate member having an adhesive layer and an alloy strip, thereby obtaining at least one second laminate having the adhesive layer and the alloy strip with the cracks formed therein; and a step of stacking the at least one second laminate on the first laminate to obtain an alloy strip laminate formed by alternating layers of the adhesive layer and the alloy strip with the cracks formed therein.

[0019] <2> according to <1> The method for manufacturing the alloy strip laminate includes the following steps for obtaining the second laminate: bonding an alloy strip to the adhesive layer of a crack-resistant tape having an adhesive layer and a release film that can be peeled off from the adhesive layer, thereby obtaining a second laminate having the release film, the adhesive layer, and the alloy strip; forming cracks in the alloy strip by directly applying external force to the alloy strip of the second laminate; and peeling off the release film to obtain a second laminate having the adhesive layer and the alloy strip with the cracks formed.

[0020] <3> according to <1> or <2> The method for manufacturing the alloy strip laminate includes the following steps for obtaining the first laminate: bonding an alloy strip to the adhesive layer of a crack-resistant tape having an adhesive layer and a release film that can be peeled off from the adhesive layer, thereby obtaining a first laminate member having the release film, the adhesive layer, and the alloy strip; forming cracks in the alloy strip by directly applying external force to the alloy strip of the first laminate member; and peeling off the release film to obtain a first laminate member having the adhesive layer and the alloy strip with the cracks formed.

[0021] <4> according to <2> or <3> In the method for manufacturing the alloy thin strip laminate, the release film is a resin-based release film.

[0022] <5> according to <1> ~ <4> In any one of the methods for manufacturing alloy strip laminates, the adhesive layer is a substrate film coated with adhesive on both sides.

[0023] <6> according to <1> ~ <5> The method for manufacturing the alloy strip laminate according to any one of the above-mentioned methods includes the step of laminating the first laminate on a protective layer having an adhesive layer and a protective film.

[0024] <7> according to <1> or <2> The method for manufacturing the alloy strip laminate includes the following steps for obtaining the first laminate: bonding an alloy strip to an adhesive layer having an adhesive layer and a protective layer having a protective film, to obtain a first laminate having the protective film, the adhesive layer, and the alloy strip; and applying an external force directly to the alloy strip of the first laminate to form cracks in the alloy strip, to obtain a first laminate having the protective film, the adhesive layer, and the alloy strip with the cracks formed therein.

[0025] <8> according to <1> ~ <7> The manufacturing method of the alloy strip laminate according to any one of the following steps includes: bonding a protective film to one or both end faces of the alloy strip laminate in the lamination direction.

[0026] <9> according to <6> ~ <8> In any one of the methods for manufacturing the alloy strip laminate, the protective film is a resin-based protective film.

[0027] <10> according to <1> The method for manufacturing the alloy strip laminate includes the following steps for obtaining the second laminate: applying an external force directly to the alloy strip while a release film that can be peeled off from the adhesive layer is disposed on the surface of the adhesive layer opposite to the surface on which the alloy strip is disposed, thereby forming the crack in the alloy strip; and peeling off the release film.

[0028] <11> according to <1> The manufacturing method of the alloy strip laminate, in the process of obtaining the first laminate, includes the following steps: applying external force directly to the alloy strip while a protective film or a release film that can be peeled off from the adhesive layer is disposed on the surface of the adhesive layer opposite to the surface on which the alloy strip is disposed, thereby forming the crack in the alloy strip.

[0029] <12> according to <1> ~ <11> In any one of the methods for manufacturing an alloy strip laminate, the formation of the cracks involves pressing a convex member against multiple locations on the surface of the alloy strip to form multiple cracks in the alloy strip.

[0030] <13> according to <12> The method for manufacturing the alloy strip laminate includes a step of forming a network of cracks that connect the multiple cracks after pressing the convex member onto the alloy strip to form the plurality of cracks.

[0031] <14> according to <1> ~ <13> The method for manufacturing an alloy strip laminate according to any one of the following methods, wherein the alloy strip is a nanocrystalline alloy strip.

[0032] <15> according to <14> The method for manufacturing the alloy strip laminate, wherein the nanocrystalline alloy strip is obtained by heat treatment of a nanocrystalline amorphous alloy strip under tension.

[0033] <16> according to <14> or <15> The method for manufacturing the alloy ribbon laminate, wherein the nanocrystalline alloy ribbon has the general formula (Fe 1-a M a ) 100-x-y-z-α-β-γ Cu x Si y B z M' α M” β X γThe composition shown in (atomic %) is as follows: 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.

[0034] <17> according to <1> ~ <16> In any one of the methods for manufacturing an alloy strip laminate, in the step of obtaining the alloy strip laminate, the alloy strip laminate obtained by stacking at least one second laminate on the first laminate is a strip-shaped alloy strip laminate, and after the step of obtaining the alloy strip laminate, there is a step of rolling the strip-shaped alloy strip laminate into a roll.

[0035] <18> according to <17> The method for manufacturing the alloy strip laminate includes the steps of unwinding and cutting the long strip alloy strip laminate that has been rolled into a roll.

[0036] <19> according to <1> ~ <16> In any one of the methods for manufacturing an alloy strip laminate, in the step of obtaining the alloy strip laminate, the alloy strip laminate obtained by stacking at least one second laminate on the first laminate is a strip-shaped alloy strip laminate, and after the step of obtaining the alloy strip laminate, there is a step of processing the strip-shaped alloy strip laminate.

[0037] <20> An apparatus for manufacturing an alloy strip laminate includes: multiple mechanisms A for bonding an alloy strip to the adhesive layer of a crack-resistant tape having an adhesive layer and a release film from which the adhesive layer can be peeled off; multiple mechanisms B for directly applying external force to the alloy strip bonded to the crack-resistant tape to form cracks in the alloy strip; multiple mechanisms C for peeling off the release film to form a laminate having the adhesive layer and the alloy strip with the cracks; and a mechanism D for laminating multiple laminates having the adhesive layer and the alloy strip with the cracks formed by multiple mechanisms A, multiple mechanisms B and multiple mechanisms C to form an alloy strip laminate.

[0038] <21> according to <20> The manufacturing apparatus for the alloy strip laminate includes a mechanism for processing the alloy strip laminate.

[0039] <22> according to <20> or <21> The manufacturing apparatus for the alloy strip laminate includes a mechanism for unwinding the alloy strip that has been rolled into a roll.

[0040] Invention Effects

[0041] According to this disclosure, a method for manufacturing an alloy strip laminate and an apparatus for manufacturing the aforementioned alloy strip laminate are provided, both capable of achieving at least one of the following: reducing the magnitude of the external force applied to the alloy strip to form multiple segments, ensuring good planarity of the segmented alloy strips, and suppressing time-dependent changes in magnetic properties. For example, according to this disclosure, the magnitude of the external force applied to the alloy strip to form cracks can be reduced, and the planarity of the cracked alloy strip can be ensured. Therefore, when alloy strips with cracks are laminated to form an alloy strip laminate, an alloy strip laminate with good planarity can be obtained. Furthermore, time-dependent changes in the magnetic properties of the alloy strip laminate can be suppressed. Moreover, an alloy strip laminate suitable for use with magnetic sheets can be obtained. Attached Figure Description

[0042] [ Figure 1 ] Figure 1 A flowchart illustrating the first embodiment.

[0043] [ Figure 2 ] Figure 2 A flowchart illustrating the second embodiment.

[0044] [ Figure 3 ] Figure 3 A flowchart illustrating a variation of the second embodiment.

[0045] [ Figure 4 ] Figure 4 A diagram illustrating the cross-section of the laminate obtained through process (1).

[0046] [ Figure 5 ] Figure 5 A diagram illustrating the laminate obtained through process (2).

[0047] [ Figure 6 ] Figure 6 A diagram illustrating the laminate obtained through process (3).

[0048] [ Figure 7 ] Figure 7 A diagram illustrating the magnetic sheet obtained through process (4).

[0049] [ Figure 8 ] Figure 8 A diagram illustrating the state of fracture and / or cracking (network cracks) in an alloy strip that connects cracks to each other.

[0050] [ Figure 9 ] Figure 9 A diagram illustrating the cross-section of the laminate obtained through process (5).

[0051] [ Figure 10 ] Figure 10 A diagram illustrating the laminate obtained through process (6).

[0052] [ Figure 11 ] Figure 11 A diagram illustrating the magnetic sheet obtained through process (7).

[0053] [ Figure 12 ] Figure 12 A diagram illustrating the additional magnetic sheet obtained in the second embodiment.

[0054] [ Figure 13 ] Figure 13 A diagram showing the manufacturing apparatus used in the first embodiment.

[0055] [ Figure 14 ] Figure 14 A diagram showing the manufacturing apparatus used in the second embodiment.

[0056] [ Figure 15 ] Figure 15 A plan view of an alloy strip showing the location where an external force is applied by a convex member.

[0057] [ Figure 16 ] Figure 16 A cross-sectional photograph showing an example of a magnetic sheet obtained by the manufacturing method of the alloy strip laminate involved in this disclosure.

[0058] [ Figure 17 ] Figure 17 This is a cross-sectional photograph of a magnetic sheet obtained by a conventional manufacturing method.

[0059] [ Figure 18 ] Figure 18 This is a cross-sectional photograph of a magnetic sheet obtained by a conventional manufacturing method.

[0060] [ Figure 19 ] Figure 19 This is a graph showing the change in permeability of a previously manufactured magnetic sheet during placement.

[0061] [ Figure 20 ] Figure 20 This is a schematic diagram of a contactless charging device.

[0062] [ Figure 21 ] Figure 21 A schematic diagram of an online annealing apparatus for obtaining nanocrystalline alloy ribbons.

[0063] [ Figure 22 ] Figure 22 A plan view showing the formation of cracks in the alloy strip.

[0064] Symbol Explanation

[0065] 1. 1A, 1B, 1C, 1D, 1E, 1F: Release film; 2. 2A, 2B, 2C: Adhesive tape; 3: Adhesive layer; 4. 4', 110: Alloy strip; 5: Crushing roller; 6. 6A: Protective layer; 6a, 6a1, 6a2: Protective film; 6b: Adhesive layer; 7: Cutting machine; 8: Tray; 9. 9', 9-1, 9-2: Crack; 10a, 10d: Laminated components; 10b, 10c: Laminated body; 10c4, 10e: First laminate; 10c1, 10c2, 10c3: Second laminate; 11: Network crack; 20a, 20b, 20c: Magnetic sheet; 200: Power supply device; 21: Power supply section; 22: Rectifier circuit; 23: Switching circuit; 24: Control... 25: Control circuit; 26: Resonance capacitor; 201: Primary coil; 300: Power receiving device; 32: Rectifier circuit; 33: Secondary battery; 34: Battery control circuit; 35: Secondary coil for control; 41, 42, 43A, 43B, 44A, 44B, 45A, 45B, 46A, 46B, 47, 48, 49, 50: Guide rollers; 60, 62: Tension adjusting rollers; 301: Secondary coil; 111: Winding body; 112: Unwinding roller; 114: Winding roller; 120: Heating chamber; 122: Heating plate; 122S: First plane; 130: Cooling chamber; 132: Cooling plate; 132S: Second plane; 150: Online annealing device. Detailed Implementation

[0066] The embodiments of this disclosure are described in detail below. This disclosure is not limited to any of the embodiments described below, and appropriate modifications can be made to implement it within the scope of the purpose of this disclosure.

[0067] When describing embodiments of this disclosure with reference to the accompanying drawings, repeated components and symbols in the drawings may sometimes be omitted from the description. Components represented by the same symbols in the drawings are identical components. The dimensional ratios in the drawings do not necessarily represent actual dimensional ratios.

[0068] In this disclosure, the numerical range represented by "~" indicates a range including the values ​​recorded before and after "~" as the lower and upper limits, respectively. Within the segmented numerical ranges described in this disclosure, the upper or lower limit recorded in a certain numerical range can be replaced with the upper or lower limit of other segmented numerical ranges. Furthermore, within the numerical ranges described in this disclosure, the upper or lower limit recorded in a certain numerical range can also be replaced with the values ​​shown in the embodiments.

[0069] In this disclosure, ordinal numbers (e.g., "first" and "second") are terms used to distinguish constituent elements, and are not used to limit the number or quality of constituent elements.

[0070] In this disclosure, the term "process" includes not only independent processes, but also any process that can achieve its desired purpose, even if it cannot be clearly distinguished from other processes.

[0071] In this disclosure, a combination of two or more preferred methods is a more preferred method.

[0072] Conventionally, to manufacture magnetic sheets consisting of multiple alloy strips made of soft magnetic materials stacked together and with cracks formed in these alloy strips, external force is applied after the multiple alloy strips are stacked to form a magnetic sheet, causing cracks to form in the alloy strips. Alternatively, after attaching a protective film or the like to both sides of at least one alloy strip to form a laminated sheet, a slicing process is performed.

[0073] One feature of this disclosure is that, before stacking multiple alloy strips, an external force is directly applied to each alloy strip to form cracks in each alloy strip.

[0074] In this disclosure, an external force is directly applied to the alloy strip to form cracks, and cracks are formed separately in each alloy strip, thereby eliminating the need for excessive external force to form cracks and suppressing excessive deformation of the alloy strip. In other words, the magnitude of the external force applied to the alloy strip to form cracks can be reduced, and the planarity of the alloy strip with cracks can be kept good.

[0075] Multiple alloy strips obtained through the above operations are stacked to form an alloy strip laminate consisting of alternating layers of cracked alloy strips and adhesive layers, thereby obtaining an alloy strip laminate with desired properties and suppressed deformation. The alloy strip laminate of this disclosure can be used, for example, as a magnetic sheet. Furthermore, the alloy strip laminate of this disclosure can also be formed into a block laminate or a toroidal laminate for use. For example, the alloy strip laminate of this disclosure can be used as a sensing element, etc.

[0076] One embodiment of this disclosure is a method for manufacturing an alloy strip laminate, comprising: (1) a step of forming cracks in the alloy strip by directly applying an external force to the alloy strip of a first laminate member having an adhesive layer and an alloy strip, thereby obtaining a first laminate having the adhesive layer and the alloy strip with the cracks formed therein; (2) a step of forming cracks in the alloy strip by directly applying an external force to the alloy strip of a second laminate member having an adhesive layer and an alloy strip, thereby obtaining at least one second laminate having the adhesive layer and the alloy strip with the cracks formed therein; and (3) a step of stacking the at least one second laminate on the first laminate to obtain an alloy strip laminate formed by alternating stacking of the adhesive layer and the alloy strip with the cracks formed therein.

[0077] In one embodiment of the manufacturing method of the alloy strip laminate disclosed herein, an external force is directly applied to a single alloy strip to form a crack. Therefore, the applied external force, based on being directly applied to the alloy strip, produces a crack strength only in the quantity of a single alloy strip. As a result, compared with conventional manufacturing methods that apply external force simultaneously to form cracks after stacking multiple alloy strips, or conventional manufacturing methods that apply external force to form cracks from a protective film, the applied external force can be smaller, the unevenness of the surface state of the segmented alloy strips is suppressed, and a good planar state can be formed. It should be noted that "good planar state" means that the surface of the object has no unevenness or has few unevennesses on the surface of the object. Regarding the segmented alloy strip, when using the term "good planar state," in addition to the above meaning, "good planar state" also refers to a state where the entire segmented alloy strip is flat when continuously observed.

[0078] The term "laminated member" used in this disclosure is used to distinguish it from a laminate having an alloy strip with cracks, and refers to a laminate having an alloy strip before cracks are formed. As described below, for example, a laminate can be formed by bonding the alloy strip to the aforementioned adhesive layer, which has an adhesive layer and a release film that can be peeled off from the adhesive layer, using a crack-resistant adhesive tape. Furthermore, for example, a laminate can also be formed by bonding the alloy strip to the aforementioned adhesive layer, which has an adhesive layer and a protective layer, including a protective film.

[0079] The term "second stack" in this disclosure is used to distinguish it from the first stack and refers to one or more stacks stacked on top of the first stack.

[0080] In one embodiment of the manufacturing method of the alloy strip laminate disclosed herein, at least one second laminate is deposited on a first laminate to form a region consisting of alternating layers of adhesive layer and alloy strip with cracks. For example, by contacting the alloy strip of one laminate (e.g., the first laminate) with the adhesive layer of another laminate (e.g., the second laminate), a region consisting of alternating layers of adhesive layer and alloy strip with cracks can be formed. The layer composition of the alloy strip laminate is not limited as long as it includes a region consisting of alternating layers of adhesive layer and alloy strip with cracks. The smallest unit of the region consisting of alternating layers of adhesive layer and alloy strip with cracks is formed by depositing two laminates (i.e., the first laminate and the second laminate) as “adhesive layer / alloy strip with cracks / adhesive layer / alloy strip with cracks”. The number of second laminates deposited on the first laminate can be two or more. When there are two or more second-layer stacks, for example, the second-layer stacks can be stacked one by one on the first-layer stack. The outermost layer located in one or both of the stacking directions of the alloy strip stack can be a layer other than the adhesive layer and the cracked metal strip (e.g., a protective film). As long as an alloy strip stack consisting of alternating layers of adhesive layer and cracked alloy strip can be obtained, the first-layer stack can also be stacked on the second-layer stack.

[0081] Furthermore, in one embodiment, the alloy strip is bonded to the release film or protective film through an adhesive layer when the crack is formed. Therefore, due to the elasticity of the release film or protective film, the generation of unevenness on the surface of the alloy strip is further suppressed. Moreover, even if unevenness occurs on the surface of the alloy strip, it will deform in a way that the unevenness becomes flat due to the elasticity of the release film or protective film. Some embodiments using a release film or protective film when forming cracks in the alloy strip will be described below.

[0082] For example, in the process of obtaining the first laminate, the formation of cracks preferably involves: applying external force directly to the alloy strip while a "protective film" or a "release film" that can be peeled off from the adhesive layer is disposed on the surface of the adhesive layer opposite to the surface where the alloy strip is disposed, thereby forming the cracks in the alloy strip. By directly applying external force to the alloy strip bonded to the protective film or release film through the adhesive layer, an alloy strip with a good surface condition can be obtained. In the above method, it is preferable that the protective film or release film is disposed at least when the external force is directly applied to the alloy strip. For example, after preparing the first laminate member having the adhesive layer and the alloy strip, and the protective film or release film, the external force can be directly applied to the alloy strip when the adhesive layer of the first laminate member comes into contact with the protective film or the release film. For example, the external force can be directly applied to the alloy strip after the protective film or release film and the first laminate member having the adhesive layer and the alloy strip are prepared in advance. The release film can be peeled off as needed after the crack is formed.

[0083] For example, the process of obtaining the first laminate preferably includes: (1) bonding an alloy strip to the adhesive layer of a crack-resistant tape having an adhesive layer and a release film that can be peeled off from the adhesive layer, thereby obtaining a first laminate having the release film, the adhesive layer, and the alloy strip; (2) forming cracks in the alloy strip by directly applying external force to the alloy strip of the first laminate; and (3) peeling off the release film to obtain a first laminate having the adhesive layer and the alloy strip with the cracks formed. By directly applying external force to the alloy strip bonded to the release film through the adhesive layer, an alloy strip with a good surface condition can be obtained.

[0084] For example, the process of obtaining the first laminate preferably includes: (1) bonding an alloy strip to the adhesive layer having an adhesive layer and a protective film, to obtain a first laminate having the protective film, the adhesive layer, and the alloy strip; and (2) forming cracks in the alloy strip by directly applying external force to the alloy strip of the first laminate, to obtain a first laminate having the protective film, the adhesive layer, and the alloy strip with the cracks formed therein. By directly applying external force to the alloy strip bonded to the protective film through the adhesive layer, an alloy strip with a good surface condition can be obtained.

[0085] For example, the process of obtaining the second laminate preferably includes: (1) applying an external force directly to the alloy strip while a release film that can be peeled off from the adhesive layer is disposed on the surface of the adhesive layer opposite to the surface on which the alloy strip is disposed, thereby forming the crack in the alloy strip; and (2) peeling off the release film. By directly applying an external force to the alloy strip bonded to the release film through the adhesive layer, an alloy strip with a good surface condition can be obtained. In the above method, it is preferable that the release film is disposed at least when an external force is directly applied to the alloy strip. For example, after preparing the second laminate member having the adhesive layer and the alloy strip and the release film respectively, an external force can be directly applied to the alloy strip when the adhesive layer of the second laminate member is brought into contact with the release film. For example, an external force can be directly applied to the alloy strip after the release film and the second laminate member having the adhesive layer and the alloy strip are prepared in advance.

[0086] For example, the process of obtaining the second laminate preferably includes: (1) bonding an alloy strip to the adhesive layer of a crack-resistant tape having an adhesive layer and a release film that can be peeled off from the adhesive layer, to obtain a second laminate having the release film, the adhesive layer, and the alloy strip; (2) forming cracks in the alloy strip by directly applying external force to the alloy strip of the second laminate; and (3) peeling off the release film to obtain a second laminate having the adhesive layer and the alloy strip with the cracks formed. By directly applying external force to the alloy strip bonded to the release film through the adhesive layer, an alloy strip with a good surface condition can be obtained.

[0087] As described above, the alloy strip laminate involved in this disclosure is manufactured by laminating alloy strips with good planarity, and therefore, the surface of the alloy strip laminate is also in good planarity.

[0088] The result is that the factors that cause changes in magnetic properties are reduced, thus enabling the production of alloy strip laminates with minimal changes in magnetic properties over time.

[0089] The alloy strip laminate disclosed herein can be a long strip alloy strip laminate. In the process of obtaining the alloy strip laminate, the alloy strip laminate obtained by overlapping at least one second laminate on a first laminate is preferably a long strip alloy strip laminate. The long strip alloy strip laminate can be manufactured, for example, using a long strip alloy strip. In the case where a long strip alloy strip laminate is obtained in the process of obtaining the alloy strip laminate, the manufacturing method of the alloy strip laminate according to one embodiment of this disclosure preferably includes a step of rolling the long strip alloy strip laminate into a roll after the step of obtaining the alloy strip laminate. Furthermore, the manufacturing method of the alloy strip laminate according to one embodiment of this disclosure preferably includes a step of unwinding and cutting the rolled long strip alloy strip laminate. Furthermore, in the case where a long strip-shaped alloy strip laminate is obtained in the process of obtaining the alloy strip laminate, the method for manufacturing the alloy strip laminate according to one embodiment of the present disclosure preferably includes a process of processing (preferably cutting out) the long strip-shaped alloy strip laminate after the process of obtaining the alloy strip laminate. Through the above process, an alloy strip laminate processed into a desired shape can be obtained.

[0090] The present disclosure will be described in further detail below, but the present disclosure is not limited to these embodiments.

[0091] It should be noted that, in the following description of the alloy strip laminate of this disclosure, a magnetic sheet is used as an example of one type of alloy strip laminate. This magnetic sheet corresponds to the alloy strip laminate of this disclosure.

[0092] [Magnetic sheet]

[0093] An example of the magnetic sheet disclosed herein is a magnetic sheet having multiple alloy strips made of soft magnetic material stacked together, and cracks formed in the alloy strips. It should be noted that the cracks in this disclosure refer to magnetic gaps formed in the alloy strips, including, for example, breaks and / or cracks in the alloy strips.

[0094] The magnetic sheet preferably has an alloy strip with fractures and / or cracks (hereinafter referred to as network cracks) forming alloy strips that connect the cracks to each other.

[0095] By forming a network of cracks in the alloy strip, the effects described in Japanese Patent Application Publication No. 2018-112830 are obtained, for example. That is, when the magnetic sheet is used as a magnetic material for a sensor, the Q value is further improved. Furthermore, when the magnetic sheet is used as a magnetic material for magnetic shielding, the current path of the alloy strip can be blocked, further reducing eddy current losses.

[0096] The magnetic sheet disclosed herein comprises multiple alloy strips stacked together. The alloy strips are stacked together, for example, by an adhesive layer. The adhesive layer can be formed using known adhesives such as acrylic adhesives, silicone adhesives, urethane adhesives, synthetic rubber, and natural rubber. Acrylic adhesives are preferred due to their excellent heat and moisture resistance and wide range of bondable materials. The adhesive layer of this disclosure can have a single-layer or multi-layer structure. For example, the adhesive layer can be a single-layer structure containing an adhesive. The adhesive layer can also be a substrate film coated with adhesive on both sides (layer composition: adhesive / substrate film / adhesive).

[0097] When there are three or more layers of alloy strip stacked together, the adhesive layers between the layers can be the same or different.

[0098] [Protective film]

[0099] Furthermore, a protective film can be further laminated onto the magnetic sheet. This protective film functions to prevent the alloy strip from unintentionally cracking or causing network cracks to increase unnecessarily, or from peeling off, or from rusting due to unintentional external forces. It also functions to prevent unnecessary deformation, such as surface unevenness, when the magnetic sheet is processed into a specified shape.

[0100] The protective film can be laminated as a single unit or as a protective layer having an adhesive layer and a protective film. When laminated as a single unit, the alloy strip and the protective film are bonded together by the adhesive layer of the sheet member described later (an example of a laminate in this disclosure, hereinafter the same). When laminated as a protective layer, the alloy strip and the protective film are bonded together by the adhesive layer of the protective layer.

[0101] The protective film is preferably laminated in a manner that covers the exposed alloy strip.

[0102] Furthermore, when forming a protective layer on a magnetic sheet, the following methods can be used: a method of stacking laminations on the protective layer; or a method of bonding an alloy strip to the protective layer, directly applying external force to the alloy strip to form cracks in the alloy strip, and then stacking laminations on the cracked alloy strip. As a specific example of the former method, the process of stacking a first laminate on a protective layer having an adhesive layer and a protective film can be cited. In the above process, it is preferable to bring the adhesive layer of the protective layer into contact with the adhesive layer of the first laminate.

[0103] The protective film is preferably a resin-based protective film, and more preferably a resin-based protective film with elasticity. As described above, for example, the process of obtaining the first laminate may include: (1) bonding an alloy strip to the adhesive layer having an adhesive layer and a protective film, to obtain a first laminate having the protective film, the adhesive layer, and the alloy strip; and (2) forming cracks in the alloy strip by directly applying external force to the alloy strip of the first laminate, to obtain a first laminate having the protective film, the adhesive layer, and the alloy strip with the cracks formed therein. If the protective film is made of resin, the generation of unevenness on the surface of the alloy strip is further suppressed due to the elasticity of the protective film. Furthermore, even if unevenness occurs on the surface of the alloy strip, it will deform in a way that the unevenness becomes flat due to the elasticity of the protective film. As a result, an alloy strip with good planarity can be produced, and a magnetic sheet with small changes in magnetic properties over time can be obtained. For example, a resin with a lower limit of tensile modulus of 0.1 GPa can be used as the resin for the protective film. If the tensile modulus is 0.1 GPa or higher, the above-mentioned effects can be easily obtained. The lower limit of the tensile modulus is preferably 0.5 GPa, more preferably 1.0 GPa. The upper limit of the tensile modulus is preferably set to 10 GPa. If the tensile modulus exceeds 10 GPa, it may sometimes suppress the deformation of the alloy strip when cracks form. The upper limit of the tensile modulus is preferably 7 GPa, more preferably 5 GPa.

[0104] Furthermore, the protective film is preferably 1 μm to 100 μm thick. If the thickness of the protective film increases, it becomes difficult to deform, sometimes hindering the placement of the magnetic sheet along curved or bent surfaces. Furthermore, if the thickness is less than 1 μm, the protective film itself is more easily deformed, leading to difficulties in operation and insufficient support for the alloy strip. Additionally, the film's strength weakens, resulting in inadequate protective function.

[0105] The magnetic sheets used in portable devices such as smartphones and mobile phones need to be relatively thin. Therefore, the upper limit of the thickness of the protective film for magnetic sheets used in portable devices is preferably set to 100μm or less, and more preferably 20μm.

[0106] Furthermore, the protective layer may include a release film that can be peeled off from the adhesive layer. In this case, the protective layer functions as a protective layer until the protective film is peeled off.

[0107] After the protective film is peeled off, the magnetic sheet is bonded to the shielded object, such as an electronic device, through the adhesive layer.

[0108] In this case, to improve the processability of the magnetic sheet, a protective film with a thickness of more than 20 μm can also be used.

[0109] The protective film can be laminated on one or both end faces of the magnetic sheet in the lamination direction. At least one of the protective films disposed on the two end faces of the magnetic sheet in the lamination direction can be made into a film that can be peeled off from the adhesive layer. For example, the protective film can be laminated on one or both end faces of the magnetic sheet in the lamination direction by a process of bonding the protective film to one or both end faces of the magnetic sheet.

[0110] In addition, the protective film can be bonded to one or both end faces of the alloy strip laminate in the lamination direction after multiple sheet components are stacked to obtain the alloy strip laminate.

[0111] Resins used as protective films include, for example, polyethylene terephthalate (PET), polyimide, polyetherimide, polyethylene naphthalate, polypropylene, polyethylene, polystyrene, polycarbonate, polysulfone, polyetherketone, polyvinyl chloride, polyvinyl alcohol, fluoropolymers, acrylic resins, and cellulose. From the viewpoint of heat resistance and dielectric loss, polyamides and polyimides are particularly preferred.

[0112] As a protective adhesive layer, known substances can be used, such as pressure-sensitive adhesives. Examples of pressure-sensitive adhesives include acrylic, silicone, urethane, synthetic rubber, and natural rubber. The adhesive layer can also be a substrate film coated with adhesive on both sides (layer composition: adhesive / substrate film / adhesive).

[0113] [Alloy Strip]

[0114] As the alloy strip, for example, an alloy strip with a thickness of 100 μm or less, manufactured by quick-cooling by roll forming, can be used. The thickness of the alloy strip is preferably 50 μm or less, more preferably 30 μm or less, and particularly preferably 25 μm or less. Furthermore, if the alloy strip is too thin, it becomes difficult to handle; therefore, the thickness of the alloy strip is preferably 5 μm or more, more preferably 10 μm or more.

[0115] For example, alloy ribbons are composed of Fe-based or Co-based alloys, and alloy ribbons of nanocrystalline alloys or amorphous alloys can be used.

[0116] As alloy ribbons, alloy ribbons composed of nanocrystalline alloys (hereinafter sometimes referred to as "nanocrystalline alloy ribbons") are particularly preferred. Nanocrystalline alloy ribbons are mechanically more brittle than amorphous alloy ribbons, and when external force is applied directly to the alloy ribbon to form cracks, the cracks can be formed with a small force. Therefore, cracks can be formed without creating significant unevenness on the surface of the alloy ribbon, thus enabling the production of alloy ribbons with excellent planarity. Furthermore, the shape of the alloy ribbon after being fabricated into a magnetic sheet exhibits minimal change over time, suppressing changes in magnetic properties over time.

[0117] As described above, in one embodiment, cracks are formed by directly applying external force to the alloy strip while a protective film or a release film that can be peeled off from the adhesive layer is disposed on the surface of the adhesive layer opposite to the surface on which the alloy strip is disposed. According to this method, cracks can be easily formed in the nanocrystalline alloy strip, thus suppressing deformation of the release film or protective film caused by external force. Therefore, alloy strips with good planarity can be manufactured, and magnetic sheets with minimal changes in magnetic properties over time can be obtained.

[0118] Alloy ribbons composed of nanocrystalline alloys can be manufactured, for example, by a manufacturing method comprising the following steps: a step of rapidly cooling the alloy melt to obtain a nanocrystalline amorphous alloy ribbon; and a heat treatment step of heat-treating the amorphous alloy ribbon above the crystallization initiation temperature to form fine grains. The heat treatment temperature varies depending on the alloy composition, but is generally above 450°C.

[0119] Fine grains, for example, are Fe with a body-centered cubic lattice structure containing solid solutions of Si. Analysis of these fine grains can be performed using X-ray diffraction and transmission electron microscopy. In nanocrystalline alloys, at least 50% by volume is comprised of fine grains with an average particle size of less than 100 nm, measured by maximum size. Furthermore, the portion of the nanocrystalline alloy excluding the fine grains is primarily amorphous. The proportion of fine grains can be essentially 100% by volume.

[0120] Furthermore, as a nanocrystalline alloy ribbon, a nanocrystalline alloy ribbon obtained by heat treatment that nanocrystallizes a nanocrystallizable amorphous alloy ribbon under tension can be used.

[0121] Examples of alloy compositions for nanocrystalline amorphous alloy ribbons include those shown in the general formula below. For instance, by heat-treating an amorphous alloy ribbon having the composition shown in the general formula below, a nanocrystalline alloy ribbon having the composition shown in the general formula below can be obtained. The nanocrystalline alloy ribbon preferably has the composition shown in the general formula below.

[0122] General formula: (Fe 1-a M a ) 100-x-y-z-α-β-γ Cu x Si y B z M' α M” β X γ (atom%)

[0123] 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.

[0124] 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.

[0125] Next, an embodiment of heat treatment will be described when using a nanocrystalline alloy strip obtained by heat treatment of nanocrystallization under tension on a nanocrystallizable amorphous alloy strip as an alloy strip.

[0126] First, the process of preparing the nanocrystallizable amorphous alloy strip of this embodiment will be described.

[0127] Nanocrystallizable amorphous alloy ribbons, for example, refer to alloy ribbons in an amorphous state that have been heat-treated to form nanocrystals. These ribbons can be manufactured by rapidly solidifying molten metal incorporated into an alloy composition that is a nanocrystal alloy. Methods for rapidly solidifying the molten metal can be called single-roll or double-roll methods. These are methods using roller cooling. Well-known methods can be applied to this roller cooling method. In this roller cooling method, molten metal is continuously rapidly cooled to obtain a long strip of amorphous alloy ribbon. The material that has been rapidly solidified in a ribbon-like form is an amorphous state lacking nanocrystals; then, nanocrystals are formed through heat treatment (nanocrystallization), forming a nanocrystal alloy ribbon. It should be noted that these long strips of amorphous alloy ribbons are mostly coiled on a spool and transported as a rolled-up body. It should also be noted that sometimes, fine crystals are present in the nanocrystallizable amorphous alloy ribbons. In this case, the fine crystals are heat-treated to form nanocrystals.

[0128] Next, the process of performing a heat treatment to nanocrystallize the amorphous alloy thin strip under tension to obtain a nanocrystalline alloy thin strip will be described.

[0129] By performing a heat treatment on a nanocrystalline amorphous alloy strip under tension, the AC relative permeability μr of the nanocrystalline alloy strip can be adjusted. Furthermore, it is preferable to obtain a nanocrystalline alloy strip with an AC relative permeability μr of 100 to 2000 through this process. It should be noted that the nanocrystalline alloy is an alloy having a microcrystalline structure with a grain size of 100 nm or less.

[0130] In this embodiment, for example, an amorphous alloy strip is continuously circulated under tension, causing a portion of the amorphous alloy strip to nanocrystallize. Nanocrystallization is achieved by applying heat above the crystallization initiation temperature, for example, by passing it through a heat treatment furnace or by contacting it with a heat transfer medium. In this specific embodiment, for example, the amorphous alloy strip under tension is contacted with a heat transfer medium, and the amorphous alloy strip is continuously circulated while maintaining contact with the heat transfer medium. Then, the amorphous alloy strip is heat-treated through the heat transfer medium to become a nanocrystalline alloy strip.

[0131] At this point, the direction of the tension applied to the amorphous alloy strip is the same as the direction of travel of the amorphous alloy strip before contact with the heat transfer medium, the direction of travel of the amorphous alloy strip when in contact with the heat transfer medium, and the direction of travel of the nanocrystalline alloy strip immediately after leaving the heat transfer medium—all are straight lines. The amorphous alloy strip processed in this way is a long, thin strip, and the length direction of this strip is the same as the direction of the applied tension.

[0132] However, the amorphous alloy strip can meander along the upstream side of its travel direction "before it immediately comes into contact with the heat transfer medium," while passing through conveyor rollers, etc. Similarly, the nanocrystalline alloy strip obtained from the amorphous alloy strip can meander along the downstream side of its travel direction "just after it leaves the heat transfer medium," while passing through conveyor rollers, etc.

[0133] The tension is preferably 1.0N to 50.0N, more preferably 2.0N to 40.0N, and particularly preferably 3.0N to 35.0N.

[0134] If the tension is above 1.0N, the permeability can be sufficiently reduced.

[0135] If the tension is below 50.0 N, it can further suppress the fracture of amorphous alloy ribbons or nanocrystalline alloy ribbons.

[0136] Furthermore, in the heat treatment for nanocrystallization in this embodiment, the amorphous alloy ribbon is heated to a temperature above the crystallization temperature Tc1 (e.g., above 430°C). Thus, nanocrystallization occurs within the microstructure of the alloy ribbon.

[0137] The preferred temperature range is 430℃~600℃.

[0138] When the temperature reaches below 600°C (especially when the B content is above 10 atomic% and below 20 atomic%, for example, the precipitation frequency of Fe-B compounds that can degrade the soft magnetic properties (Hc, Bs, etc.) of nanocrystalline alloy ribbons is lower.

[0139] Furthermore, it is preferable to set the arrival temperature to be the same as the temperature of the heat transfer medium.

[0140] Furthermore, when using a heat transfer medium in the heat treatment of nanocrystallization, examples of suitable heat transfer media include plates and twin rollers, with plate-shaped media having the most contact surfaces with the amorphous alloy strip being preferred. The contact surfaces of the plate-shaped medium are preferably flat, but some curved surfaces can also be provided. Additionally, suction holes can be provided at the contact surface between the heat transfer medium and the alloy strip, allowing for depressurized suction. This allows the alloy strip to be attracted and adsorbed onto the surface of the heat transfer medium with suction holes, improving the contact between the alloy strip and the heat transfer medium and thus increasing the heat treatment efficiency.

[0141] In addition, materials that can be used as heat transfer media include, for example, copper, copper alloys (bronze, brass, etc.), aluminum, iron, and iron alloys (stainless steel, etc.). Among these, copper, copper alloys, or aluminum have high thermal conductivity and are preferred.

[0142] The heat transfer medium can be electroplated with Ni, Ag, or other plating processes.

[0143] In addition, a separate component can be provided to heat the heat transfer medium, thereby bringing the heated heat transfer medium into contact with the amorphous alloy strip and heating the amorphous alloy strip for heat treatment. Alternatively, an optional component can be used to surround the heat transfer medium.

[0144] Furthermore, in this embodiment, after the temperature is raised to the target temperature, the temperature of the nanocrystalline alloy strip can be maintained for a certain period of time on the heat transfer medium.

[0145] Furthermore, in this embodiment, it is preferable to cool the obtained nanocrystalline alloy ribbon (preferably to room temperature).

[0146] Furthermore, this embodiment may include a wound of nanocrystalline alloy strip obtained by rolling up the obtained nanocrystalline alloy strip (preferably the cooled nanocrystalline alloy strip described above).

[0147] The thickness of the nanocrystallizable amorphous alloy ribbon in this embodiment is preferably in the range of 10 μm to 50 μm. If the thickness is less than 10 μm, the mechanical strength of the alloy ribbon itself is low, making it difficult to stably cast long strips of alloy ribbon. Furthermore, if the thickness exceeds 50 μm, the alloy is prone to partial crystallization, resulting in property degradation. The thickness of the amorphous alloy ribbon is more preferably 11 μm to 30 μm, and even more preferably 12 μm to 27 μm.

[0148] Furthermore, the width of the amorphous alloy ribbon is not particularly limited, but is preferably 5 mm to 300 mm. If the width of the amorphous alloy ribbon is 5 mm or more, its manufacturability is excellent. If the width of the amorphous alloy ribbon is 300 mm or less, the uniformity of nanocrystallization is higher in the process of obtaining the nanocrystalline alloy ribbon. The width of the amorphous alloy ribbon is preferably 200 mm or less.

[0149] It should be noted that, in this embodiment, the following continuous production line can also be set up to produce nanocrystalline alloy strips: an amorphous alloy strip is unwound from an amorphous alloy strip that is configured as a roll, tension is applied to the amorphous alloy strip while it is moved forward, the moving amorphous alloy strip is brought into contact with a heat transfer medium and heated, heat treatment is performed through this heating, thereby nanocrystallization is carried out to obtain a nanocrystalline alloy strip, and the nanocrystalline alloy strip is rolled into a roll.

[0150] use Figure 21 One embodiment of a method for producing nanocrystalline alloy strips by setting up a continuous production line will be described. Figure 21 The device shown is an online annealing apparatus 150, which is an apparatus for performing the following online annealing process: from the unwinding roll to the winding roll, a long strip of amorphous alloy strip is subjected to a continuous heat treatment process including a heating process and a cooling process to obtain a nanocrystalline alloy strip.

[0151] The online annealing apparatus 150 includes an unwinding roller 112 (unwinding device) for unwinding an alloy strip 110 from a winding body 111 of an amorphous alloy strip, a heating plate (heat transfer medium) 122 for heating the alloy strip 110 unwound from the unwinding roller 112, a cooling plate (heat transfer medium) 132 for cooling the alloy strip 110 heated by the heating plate 122, and a winding roller 114 (winding device) for winding the alloy strip 110 cooled by the cooling plate 132. Figure 21 In the diagram, arrow R indicates the direction of travel of alloy strip 110.

[0152] A winding body 111 of amorphous alloy strip is placed on the unwinding roller 112.

[0153] The alloy strip 110 is unwound from the winding body 111 of the amorphous alloy strip by the unwinding roller 112 rotating axially in the direction of arrow U.

[0154] In this example, the unwinding roller 112 itself may have a rotating mechanism (e.g., a motor), or the unwinding roller 112 itself may not have a rotating mechanism.

[0155] When the unwinding roller 112 itself does not have a rotating mechanism, it is linked with the winding action of the alloy strip 110 carried out by the winding roller 114 (described later) to unwind the alloy strip 110 from the winding body 111 of the amorphous alloy strip placed on the unwinding roller 112.

[0156] Figure 21 As shown in the enlarged portion surrounded by a circle, the heating plate 122 includes a first plane 122S on which the alloy strip 110, unwound from the unwinding roller 112, travels while in contact with the first plane 122S. The heating plate 122 heats the alloy strip 110, which travels on the first plane 122S while in contact with it, through the first plane 122S. As a result, the traveling alloy strip 110 is stably and rapidly heated and nanocrystalline.

[0157] The heating plate 122 is connected to a heat source (not shown) and is heated to the desired temperature using heat supplied from the heat source. Alternatively, the heating plate 122 may have a heat source internally, either directly connected to a heat source or in conjunction with a heat source connection.

[0158] Materials used for the heating plate 122 include, for example, stainless steel, Cu, Cu alloy, Al alloy, etc.

[0159] The heating plate 122 is housed in the heating chamber 120.

[0160] The heating chamber 120 may also have a heat source for controlling the temperature of the heating chamber that is different from the heat source for the heating plate 122.

[0161] The heating chamber 120 has openings (not shown in the figure) on the upstream and downstream sides of the alloy strip 110 in the traveling direction (arrow R) for the alloy strip to enter or exit. The alloy strip 110 enters the heating chamber 120 through the inlet of the upstream opening and exits from the heating chamber 120 through the outlet of the downstream opening.

[0162] also, Figure 21 As shown in the enlarged portion surrounded by a circle, the cooling plate 132 includes a second plane 132S on which the alloy strip 110 contacts and travels. The cooling plate 132 cools the alloy strip 110, which contacts and travels on the second plane 132S.

[0163] The cooling plate 132 may have a cooling mechanism (e.g., a water cooling mechanism) or it may not have a special cooling mechanism.

[0164] Materials used for cooling plate 132 include, for example, stainless steel, Cu, Cu alloy, Al alloy, etc.

[0165] The cooling plate 132 is housed in the cooling chamber 130.

[0166] The cooling chamber 130 may or may not have a cooling mechanism (e.g., a water cooling mechanism). That is, the cooling method of the cooling chamber 130 can be water cooling or air cooling.

[0167] The cooling chamber 130 has openings (not shown in the figure) on the upstream and downstream sides of the alloy strip 110 in the traveling direction (arrow R) for the alloy strip to enter or exit. The alloy strip 110 enters the cooling chamber 130 through the inlet of the upstream opening and exits from the cooling chamber 130 through the outlet of the downstream opening.

[0168] The winding roller 114 has a rotating mechanism (e.g., a motor) that rotates along its axis in the direction of arrow W. By rotating the winding roller 114, the alloy strip 110 is wound at a desired speed.

[0169] In the online annealing apparatus 150, between the unwinding roller 112 and the heating chamber 120, along the travel path of the alloy strip 110, there are guide rollers 41, tension adjusting rollers 60 (a type of tensile stress adjusting device), guide rollers 42, and a pair of guide rollers 43A and 43B. The adjustment of tensile stress is also achieved by controlling the movement of the unwinding roller 112 and the winding roller 114.

[0170] The tension adjusting roller 60 can be adjusted in the vertical direction ( Figure 21The tension adjustment roller 60 is set to move in the direction of the arrows on both sides. The tensile stress of the alloy strip 110 can be adjusted by adjusting the position of the tension adjustment roller 60 in the vertical direction.

[0171] Therefore, it is possible to perform nanocrystallization heat treatment while applying tension to amorphous alloy strips.

[0172] The alloy strip 110 unwound from the unwinding roll 112 is guided into the heating chamber 120 via these guide rolls and tension adjustment rolls.

[0173] The online annealing apparatus 150 has a pair of guide rollers 44A and 44B and a pair of guide rollers 45A and 45B between the heating chamber 120 and the cooling chamber 130.

[0174] The alloy strip 110 exiting the heating chamber 120 is guided into the cooling chamber 130 via these guide rollers.

[0175] In the online annealing apparatus 150, between the cooling chamber 130 and the winding roller 114, along the travel path of the alloy strip 110, there are a pair of guide rollers 46A and 46B, guide roller 47, tension adjusting roller 62, guide roller 48, guide roller 49, and guide roller 50.

[0176] The tension adjusting roller 62 can be adjusted in the vertical direction ( Figure 21 The tension adjustment roller 62 is set to move in the direction of the arrows on both sides. By adjusting the position of the tension adjustment roller 62 in the vertical direction, the tensile stress of the alloy strip 110 can be adjusted.

[0177] The alloy strip 110 exiting the cooling chamber 130 is guided to the winding roller 114 via these guide rollers and tension adjustment rollers.

[0178] In the online annealing apparatus 150, in order to make full contact between the alloy strip 110 and the first plane 122S of the heating plate 122, the guide rollers (43A, 43B, 44A and 44B) arranged on the upstream and downstream sides of the heating chamber 120 have the function of adjusting the position of the alloy strip 110.

[0179] In the online annealing apparatus 150, in order to make full contact between the alloy strip 110 and the second plane 132S of the cooling plate 132, the guide rollers (45A, 45B, 46A and 46B) arranged on the upstream and downstream sides of the cooling chamber 130 have the function of adjusting the position of the alloy strip 110.

[0180] The online annealing apparatus 150 can be used to produce nanocrystalline alloy strips, and the aforementioned alloy strip laminates can be produced using the nanocrystalline alloy strips.

[0181] [Crack tape]

[0182] In one embodiment, when a crack is formed in the alloy strip, a crack-forming tape is adhered to the alloy strip.

[0183] The crack-making tape has an adhesive layer and a release film that can be peeled off from the adhesive layer. The crack-making tape is adhered to one side of an alloy strip, supporting the alloy strip when cracks form. Then, the release film is peeled off, exposing the adhesive layer, thus creating a sheet component (an example of a laminate of this disclosure) having the adhesive layer and the cracked alloy strip. The sheet component can be bonded to other alloy strips, etc., via the adhesive layer. The adhesive layer of the crack-making tape remains on the magnetic sheet. Sometimes, the release film peels off from the adhesive layer during manufacturing, resulting in a situation where it does not remain on the magnetic sheet.

[0184] [Release film]

[0185] The release film is preferably a resin-based release film, and more preferably an elastic resin-based release film.

[0186] One embodiment of this disclosure relates to a method for manufacturing an alloy strip laminate, comprising a step of bonding an alloy strip to a crack-resistant adhesive tape having an adhesive layer and a release film from which the adhesive layer can be peeled off, and a step of directly applying external force to the alloy strip to form cracks. In this case, if the release film is made of resin, the generation of unevenness on the surface of the alloy strip is suppressed due to the elasticity of the release film. Furthermore, even if unevenness occurs on the surface of the alloy strip, it will deform in a way that the unevenness becomes flat due to the elasticity of the release film. As a result, an alloy strip with good planarity can be manufactured, and a magnetic sheet with minimal change in magnetic properties over time can be obtained.

[0187] For example, the resin used as the release film can be a resin with a lower limit of tensile modulus of 0.1 GPa. If the tensile modulus is 0.1 GPa or higher, the aforementioned effects are easily obtained. The lower limit of the tensile modulus is preferably 0.5 GPa, more preferably 1.0 GPa. The upper limit of the tensile modulus is preferably set to 10 GPa. If it exceeds 10 GPa, deformation of the alloy strip may be inhibited when cracks form. The upper limit of the tensile modulus is preferably 7 GPa, more preferably 5 GPa. The resin of the release film can be the same material as the resin of the protective film of the protective layer.

[0188] Furthermore, the release film is preferably a release film with a thickness of 1 μm to 100 μm. If the thickness of the release film is increased, it becomes difficult to deform, which may sometimes hinder the magnetic sheet from being positioned along curved or bent surfaces. In addition, if the thickness is less than 1 μm, the release film itself is more easily deformed, making it difficult to handle and sometimes failing to fully achieve the function of supporting the alloy strip.

[0189] The adhesive layer can be the same as the adhesive layer of the protective layer.

[0190] [crack]

[0191] Cracks can be formed, for example, by pressing a convex member onto the surface of an alloy strip. The shape of the convex member can be, for example, rod-shaped or conical. The front end of the convex member can be flat, conical, centrally concave, or cylindrical.

[0192] In the formation of cracks, it is preferable to press protruding members at multiple locations on the surface of the alloy strip to form multiple cracks in the alloy strip. For example, a pressure member with multiple protruding members regularly arranged can be used to form cracks. For example, a roller (hereinafter referred to as a cracking roller) with multiple protruding members arranged on its circumferential surface can be used to form cracks. For example, cracks can be continuously formed by pressing a long strip of alloy strip onto the cracking roller or by passing a long strip of alloy strip through the gaps between the cracking rollers. Alternatively, multiple cracking rollers can be used to form cracks.

[0193] Figure 15 A plan view of the alloy strip showing the location where an external force is applied by a convex member. The shape of the pattern within the alloy strip corresponds to the shape of the front end of the convex member at the point where the external force is applied.

[0194] Figure 15 (a) A diagram conceptually showing the location where an external force is applied when using a convex member with a circular end cross-section.

[0195] Figure 15 (b) A diagram conceptually showing the location where an external force is applied when using a convex member with a cross-shaped end.

[0196] Figure 15 (c) A diagram conceptually showing the positions of applied external forces when using convex members with end shapes that are lines in the longitudinal and transverse directions of the graphic. In this diagram, the positions of applied external forces are arranged in a discontinuous and matrix-like manner.

[0197] Figure 15 (d) For conceptual display purposes, the end shape is tilted θ° relative to the longitudinal direction of the graphic. Figure 15 (d) a linear convex member inclined at 45° and an inclined (θ°) member. Figure 15 (d) is a diagram showing the location of the applied external force when the linear convex member is tilted at -45°. In this diagram, the locations of the applied external force are arranged in a discontinuous manner, with one linear location of the applied external force intersecting the two ends of another location of the applied external force on its extension.

[0198] Figure 15 (e) For conceptual display purposes, the end profile is tilted θ° relative to the longitudinal direction of the graphic. Figure 15 (e) Inclined at 45°) linear convex member and -θ° ( Figure 15(e) is a diagram showing the location of the applied external force when the linear convex member is tilted at -45°. In this diagram, the locations of the applied external force are arranged in a discontinuous and tilted matrix.

[0199] Figure 15 (f) is a conceptual diagram showing the position of the applied external force when using a convex member with an end shape that is a line in the longitudinal direction and a convex member with a line in the transverse direction, respectively. It is relative to the position of the applied external force. Figure 15 (c) refers to the diagram where the positional relationships have changed. The configuration of the convex members is not limited to the case shown in the diagram and can be set appropriately.

[0200] The locations where external forces are applied preferably form cracks with the exact same shape as the location where the external force is applied. However, it is also possible for other types of cracks to form, or for cracks not to form the same shape (partially no cracks to form).

[0201] Alternatively, the cracks can be formed by making them linear and connecting multiple cracks continuously.

[0202] form Figure 15 (c) Figure 15 (d) Figure 15 (e) or Figure 15 In the case of cracks in (f), for example, a convex member can be placed on a cracking roller and another convex member can be placed on another cracking roller, and the two cracking rollers can be used to apply external force directly to the alloy strip in sequence to form cracks.

[0203] In the formation of cracks using a convex member, it is preferable to further connect multiple cracks to form a network crack. Specifically, in one embodiment, after forming multiple cracks by pressing the convex member onto the alloy strip, it is preferable to have a step of forming a network crack that connects the multiple cracks to each other. For example, after forming cracks by directly applying external force to the alloy strip with the convex member, a second external force can be applied using a device that bends or winds the alloy strip. This allows for the formation of fractures and / or cracks (magnetic gaps connecting the cracks) that connect the cracks, starting from the cracks as the starting point of brittle fracture and / or cracking fracture. Alternatively, in the step of forming the network crack, the second external force described above may not be applied, and the network crack may be formed during the formation of multiple cracks.

[0204] [Manufacturing Process]

[0205] The following describes a specific embodiment of the method for manufacturing the alloy strip laminate disclosed herein. First, the first embodiment will be described. Figure 1 This is a flowchart of the first embodiment.

[0206] The first embodiment is a method for manufacturing a magnetic sheet as described below.

[0207] The first embodiment is a method for manufacturing a magnetic sheet, which is a method for manufacturing a magnetic sheet having multiple alloy strips made of soft magnetic material stacked together and having cracks formed in the alloy strips, comprising: a step of bonding the alloy strips to the adhesive layer having an adhesive layer and a release film that can be peeled off from the adhesive layer with a crack adhesive tape. Figure 1 The process (1) involves directly applying external force to the aforementioned alloy strip to form cracks. Figure 1 The process (2) involves peeling the release film from the adhesive layer to form a sheet component having the adhesive layer and the alloy strip with the cracks. Figure 1 The process (3) and the process of stacking multiple of the above-mentioned sheet components ( Figure 1 The process (4)). The multiple sheet components used in the above process (4) are supplied, for example, by repeating a series of processes including the above process (1), the above process (2) and the above process (3) multiple times.

[0208] In the first embodiment, in step (1), an alloy strip is bonded to a crack tape having an adhesive layer and a release film that can be peeled off from the adhesive layer.

[0209] For crack sealing, a tape with an integrated adhesive layer and release film can be used. Similarly, a tape with a separately prepared adhesive layer and release film, which is then integrated together, can also be used.

[0210] Figure 4 A diagram illustrating the cross-section of the laminated component 10a obtained through process (1). The laminated component 10a contains an alloy strip 4, an adhesive layer 3, and a release film 1.

[0211] In the first embodiment, in process (2), an external force is directly applied to the alloy strip to form cracks.

[0212] In this manner, the present disclosure applies external force directly to the alloy strips before stacking them, rather than after stacking multiple alloy strips, to form cracks. Therefore, since the applied external force is directly applied to the alloy strips, the crack strength is generated only in a single alloy strip. As a result, compared to conventional manufacturing methods that simultaneously form cracks in multiple alloy strips or that form cracks by applying external force to a protective film, cracks can be formed with a smaller external force. Therefore, the unevenness of the surface of the cracked alloy strip can be suppressed, resulting in a good planarity of the alloy strip.

[0213] Furthermore, in step (2), the crack formation is carried out while the alloy strip is bonded to the release film. Therefore, due to the elasticity of the release film, the generation of unevenness on the surface of the alloy strip is suppressed, resulting in a good planar state of the alloy strip. In addition, even if unevenness occurs on the surface of the alloy strip, it will deform in a way that the unevenness becomes flat due to the elasticity of the release film. As a result, a magnetic sheet with small changes in magnetic properties over time can be obtained.

[0214] Figure 5 A diagram illustrating the laminate 10b obtained through process (2). Figure 5 (2-a) is a plan view viewed from the stacking direction. Figure 5 (2-b) is Figure 5 (2-a) AA section diagram. It should be noted that, as will be discussed later... Figure 6 , Figure 7 , Figure 10 , Figure 11 and Figure 12 In the middle, above and below ( -a) and ( The diagram for -b) also shows the same relationship, so further explanation is omitted.

[0215] The laminate 10b contains an alloy strip 4, an adhesive layer 3, and a release film 1. Furthermore, the alloy strip 4 has multiple linear cracks 9 regularly formed, extending in the vertical direction as shown in the attached figure. Figure 5 As shown in (2-b), crack 9 is a break and / or crack formed in the alloy strip 4. The release film, as described above, is preferably made of an elastic resin.

[0216] It should be noted that, in the case of linear cracks forming in the alloy strip, it is preferable to, for example, as shown in the example... Figure 22 As shown, it is formed parallel to the casting direction of the alloy strip (equivalent to the length direction during continuous casting (rapid solidification) using roller cooling, which is the direction along the rotation direction of the roller). It should be noted that... Figure 22 The arrow shown indicates the casting direction.

[0217] In the first embodiment, the release film is peeled off in step (3). Release films are not used in conventional manufacturing methods, but in this disclosure, they are used in step (2) as an auxiliary component to prevent unevenness from appearing in the alloy strip when an external force is applied directly to the alloy strip to form cracks.

[0218] Figure 6 The diagram illustrates the laminate 10c (i.e., sheet component) obtained through process (3). The laminate 10c (i.e., sheet component) contains an alloy strip 4 and an adhesive layer 3. It should be noted that the release film is peeled off.

[0219] In the first embodiment, in step (4), multiple sheet components are stacked. The magnetic sheet is manufactured by directly stacking alloy strips with no or few irregularities on the surface where cracks were formed in step (2) and with good planarity. Therefore, after the magnetic sheet is made, the surface of the alloy strip has few irregularities and good planarity, and a magnetic sheet with small changes in magnetic properties over time can be obtained.

[0220] Figure 7 The diagram illustrates the magnetic sheet 20a (alloy strip laminate) obtained through process (4). The magnetic sheet 20a has multiple sheet components stacked in it. The multiple sheet components include three second laminates (10c1~10c3) and a first laminate 10c4.

[0221] In the magnetic sheet 20a of this embodiment, such as Figure 7 As shown in (4-a), the cracks 9 formed in the second laminate 10c1, 9-1 formed in the second laminate 10c2, and 9-2 formed in the second laminate 10c3 are located at different positions when viewed from the lamination direction. In this way, in one example of the present disclosure, external force is directly applied to each alloy strip to form cracks. Therefore, unlike conventional manufacturing methods that form cracks simultaneously in multiple alloy strips, the position of the cracks in each layer of the alloy strip can be changed, thus enabling the formation of a magnetic sheet with uniformly formed magnetic gaps. Therefore, when the magnetic sheet is further punched or cut into a desired shape, the change in permeability due to the processing position is small, and a magnetic sheet with stable shielding properties can be manufactured. It should be noted that the crack 9-4 in the first laminate 10c4 is formed at a position that coincides with the crack 9 formed in the second laminate 10c1.

[0222] As another step in the first embodiment, for example, a step of laminating a protective film onto the second laminate 10c1 can be employed. Using the protective film, it is possible to prevent the alloy strip from unintentionally increasing cracks and network cracks due to external forces, or from the alloy strip falling off, or from the alloy strip rusting. Furthermore, the protective film functions in a way that does not create unnecessary surface irregularities when processing the magnetic sheet into a specified shape.

[0223] The process of laminating the protective film can be carried out in any of the processes (1) to (4).

[0224] Figure 8 A diagram illustrating the state of fracture and / or cracking (network cracking) in thin alloy bands that connect cracks to each other. Specifically, Figure 8This is a schematic diagram showing the morphology of cracks 9 and network cracks 11 formed in the alloy strip. When cracks 9 are discontinuous, a second external force such as bending or winding can be applied to the alloy strip 4, with cracks 9 as the starting point of brittle fracture, forming fractures and / or cracks in the alloy strip 4, forming a network crack 11 that connects the cracks 9 to each other by the fractures and / or cracks (magnetic gaps that connect the cracks 9 to each other).

[0225] The formation of network crack 11 is possible as long as it occurs after process (2).

[0226] Next, use Figure 13 An example of a magnetic sheet manufacturing apparatus used in the first embodiment and a method for manufacturing a magnetic sheet using the above-described manufacturing apparatus will be described. Figure 13 The apparatus for manufacturing the magnetic sheet shown includes: multiple mechanisms A for bonding an alloy strip to a crack-resistant adhesive tape having an adhesive layer and a release film from which the adhesive layer can be peeled off; multiple mechanisms B for directly applying external force to the alloy strip bonded to the crack-resistant adhesive tape to form cracks in the alloy strip; multiple mechanisms C for peeling off the release film to form a laminate having the adhesive layer and the alloy strip with the cracks; and a mechanism D for laminating multiple laminates having the adhesive layer and the alloy strip with the cracks formed by multiple mechanisms A, multiple mechanisms B, and multiple mechanisms C to form an alloy strip laminate. Further, Figure 13 The apparatus for manufacturing magnetic sheets shown includes a mechanism for unwinding a rolled alloy strip and a mechanism for processing the magnetic sheet. The specific product names and values ​​shown below are examples used to explain in detail the manufacturing method and apparatus for magnetic sheets.

[0227] • Embodiment of process (1): "The process of bonding an alloy strip to the adhesive layer of a crack adhesive tape having an adhesive layer and a release film that can be peeled off from the adhesive layer"

[0228] First, the rollers formed by winding tape 2A are positioned in four locations. Then, tape 2A is pulled out from the rollers. Tape 2A is a three-layer structure consisting of release film 1A (25μm), an adhesive layer (5μm), and release film 1B (25μm). Release films 1A and 1B are made of the same material (PET) with a tensile elasticity of 3.9 GPa. The adhesive layer is a substrate film coated on both sides with an acrylic adhesive. Release films 1A and 1B can be peeled off from the adhesive layer.

[0229] Release film 1A is peeled off from tape 2A. The peeling of release film 1A is performed at approximately the same time as tape 2A is pulled out from the roller. In this embodiment, the tape consisting of an adhesive layer and release film 1B obtained by peeling release film 1A is used as a crack tape.

[0230] The alloy strip 4 used in process (1) is a long strip of alloy strip. The alloy strip 4 is wound on a roller. The roller on which the alloy strip 4 is wound is an example of a mechanism for unwinding the rolled alloy strip. The alloy strip 4 is pulled out from the roller and bonded to the adhesive layer of the crack tape using a pressing roller, which is an example of mechanism A. The alloy strip 4 is an alloy strip made of Fe-Cu-Nb-Si-B nanocrystalline alloy (FT-3 manufactured by Hitachi Metals Corporation). Figure 13 In the manufacturing apparatus shown, the alloy strip 4 moves continuously until it is cut by the cutting machine 7 described later.

[0231] • Implementation method of process (2) "the process of directly applying external force to the alloy strip to form cracks"

[0232] Cracks are formed by directly applying external force to the alloy strip 4 bonded to the cracking tape using a cracking roller 5, which is one example of mechanism B. The cracking roller 5 has multiple protruding members regularly arranged on its circumferential surface. When forming cracks, a compression roller can also be arranged on the release film 1B side to press the alloy strip 4 towards the cracking roller side, so that the external force from the cracking roller does not escape.

[0233] • Implementation method of process (3): “the process of peeling the release film from the adhesive layer to form a sheet component having an adhesive layer and an alloy strip with cracks”

[0234] The release film 1B is peeled off from the adhesive layer of the tape through the cracks, exposing the adhesive layer. By peeling off the release film 1B, a sheet component with an adhesive layer and an alloy strip with cracks is formed. The peeling of the release film 1B is performed using a roller, which is an example of mechanism C. The network cracks can also be formed by using the external force generated on the alloy strip 4 when peeling off the release film 1B. Figure 13 The manufacturing apparatus shown has four combinations of mechanisms A, B and C for performing steps (1) to (3), but the number of such combinations is not limited to four. Depending on the purpose, there may be more than five or less.

[0235] • Implementation method of process (4) "process of stacking multiple sheet components"

[0236] Multiple sheet components manufactured in processes (1) to (3) are stacked using compression rollers in an alternating manner of adhesive layers and alloy strips to obtain magnetic sheets. The compression roller is an example of mechanism D. Multiple sheet components are stacked on protective layer 6A.

[0237] It should be noted that, Figure 13 In the first embodiment shown, a protective layer 6A is bonded to one end face of the magnetic sheet in the stacking direction, and a protective film 6a is bonded to the other end face.

[0238] Protective layer 6A is an adhesive layer bonded to one end face of the magnetic sheet in the stacking direction. Protective layer 6A is a two-layer structure consisting of an adhesive layer with a thickness of 5 μm and a protective film with a thickness of 75 μm. It should be noted that the protective film can be peeled off from the adhesive layer. The adhesive layer of the sheet component and the adhesive layer of the protective layer are bonded using a pressing roller. If the protective film is peeled off, the adhesive layer of the protective layer is exposed, allowing the magnetic sheet to be bonded to electronic devices, etc.

[0239] The protective film 6a is bonded to the alloy strip on the other end of the magnetic sheet through the adhesive layer of another adhesive tape 2B. Adhesive tape 2B has a three-layer structure consisting of release film 1C, an adhesive layer (5 μm), and release film 1D. Release films 1C and 1D can be peeled off from the adhesive layer. Release film 1C is peeled off from adhesive tape 2B, and the exposed adhesive layer is bonded to the alloy strip using a pressing roller. Then, release film 1D is peeled off. Further, the protective film 6a is pressed against the adhesive layer of adhesive tape 2B. The protective film 6a is a 25 μm thick PET protective film.

[0240] In the first embodiment, after the protective film 6a is stacked, the magnetic sheet is cut to the necessary size using a cutting machine 7 and conveyed to the tray 8. The cutting machine 7 is an example of a mechanism for processing the magnetic sheet. Instead of the cutting machine 7, a processing device such as a punching die can be used to process it into the desired shape.

[0241] The second embodiment will be described. Figure 2 A flowchart illustrating the second embodiment.

[0242] The second embodiment is the method for manufacturing the magnetic sheet described below.

[0243] The second embodiment is a method for manufacturing a magnetic sheet, which is a method for manufacturing a magnetic sheet having multiple alloy strips made of soft magnetic material stacked together and having cracks formed in the alloy strips, comprising: a step of bonding the alloy strips to the adhesive layer having an adhesive layer and a release film that can be peeled off from the adhesive layer with a crack adhesive tape. Figure 2 The process (1) involves directly applying external force to the aforementioned alloy strip to form cracks. Figure 2 The process (2) involves peeling the release film from the adhesive layer to form a sheet component having the adhesive layer and the alloy strip with the cracks. Figure 2 The process (3) involves bonding the alloy strip to the aforementioned adhesive layer, which has an adhesive layer and a protective film. Figure 2 The process (5) involves applying external force directly to the alloy strip bonded to the above-mentioned protective layer to form cracks. Figure 2 The process (6) and the process of laminating the sheet component on the alloy strip bonded to the above protective layer ( Figure 2 Process (7)).

[0244] In the second embodiment, there are the same steps (1) to (3) as in the first embodiment.

[0245] The descriptions of steps (1) to (3) are omitted.

[0246] In the second embodiment, in step (5), the alloy strip is bonded to the adhesive layer having an adhesive layer and a protective film.

[0247] The protective layer can be a protective layer in which the adhesive layer and the protective film are integrated, or a protective layer in which the adhesive layer and the protective film are prepared separately and then integrated.

[0248] It should be noted that process (5) can be performed simultaneously with processes (1) to (3).

[0249] Figure 9 A diagram illustrating the cross-section of the laminated member 10d obtained through process (5). The laminated member 10d contains an alloy strip 4' and a protective layer 6 consisting of an adhesive layer 6b and a protective film 6a.

[0250] The protective layer can be a protective layer sold as a single unit consisting of the adhesive layer and the protective film, or it can be a protective layer that is prepared separately for the adhesive layer and the protective film and then integrated together.

[0251] The adhesive layer and protective film of the protective layer are made of the same materials as described above.

[0252] In the second embodiment, in step (6), an external force is applied directly to the alloy strip bonded to the protective layer to form a crack.

[0253] In this manner, the present disclosure applies external force directly to the alloy strips before and after laminating them, rather than after, to form cracks. Therefore, since the applied external force is directly applied to the alloy strips, the crack strength is generated only in the amount of one alloy strip. Thus, compared to conventional manufacturing methods that simultaneously form cracks in multiple alloy strips or that form cracks by applying external force from above the protective film, cracks can be formed with a smaller external force. Because the external force used to form cracks is small, the unevenness of the surface of the cracked alloy strip can be suppressed, resulting in a good planarity of the alloy strip.

[0254] Furthermore, in step (6), crack formation occurs while the alloy strip is bonded to the protective film. Therefore, due to the elasticity of the protective film, the generation of unevenness on the surface of the alloy strip is suppressed, resulting in a good planar state of the alloy strip. Moreover, even if unevenness occurs on the surface of the alloy strip, it will deform in a way that the unevenness becomes flat due to the elasticity of the protective film. As a result, a magnetic sheet (alloy strip laminate) with minimal change in magnetic properties over time can be obtained.

[0255] Figure 10 A diagram illustrating the first laminate 10e obtained through process (6) is provided. Multiple linear cracks 9' extending in the vertical direction along the diagram are regularly formed in the alloy strip 4'. Figure 10 As shown in (6-b), crack 9' is a fracture and / or crack formed in alloy strip 4'.

[0256] The protective film is preferably a protective film made of elastic resin. The preferred ranges for the tensile modulus and thickness of the resin in the protective film, as well as the type of resin, are as described above.

[0257] In the second embodiment, in step (7), the sheet component (i.e., the second laminate 10c3) obtained in steps (1) to (3) is laminated on the alloy strip bonded to the protective layer. Both the alloy strip of the sheet component and the alloy strip bonded to the protective layer are alloy strips with no surface irregularities or few surface irregularities and good planarity. These alloy strips are directly laminated, so after the magnetic sheet is made, the surface irregularities of the alloy strip are small and the planarity is good, which can obtain a magnetic sheet with small changes in magnetic properties over time.

[0258] Figure 11 A diagram illustrating the magnetic sheet 20b obtained through process (7). Figure 11 As shown in (7-a), in the magnetic sheet 20b, a second laminate 10c3 is stacked on the alloy strip 4' bonded to the protective layer 6. In this magnetic sheet 20b, the cracks 9 formed in the alloy strip 4 of the second laminate 10c3 and the cracks 9' formed in the alloy strip 4' bonded to the protective layer 6 are formed at different locations when viewed from the lamination direction. In this way, in this disclosure, external force is directly applied to each alloy strip to form cracks. Therefore, unlike conventional manufacturing methods that simultaneously form cracks in multiple alloy strips, the position of the cracks can be changed in each layer of the alloy strip, thus enabling the creation of a magnetic sheet with uniformly formed magnetic gaps. Therefore, when this magnetic sheet is further punched or cut into a desired shape, the change in permeability due to the processing position is small, and a magnetic sheet with stable shielding properties can be manufactured.

[0259] The magnetic sheet may have an additional protective film or layer laminated on the side opposite to the protective layer 6 in the lamination direction. A release film that can be peeled off from the adhesive layer may be used as a protective film in any of the protective layers.

[0260] In the second embodiment, it can also be combined with Figure 8 The explanation also forms network crack 11.

[0261] In the second embodiment, a process of further stacking other sheet components on the sheet component can be performed. Figure 3 The process (4) of further stacking another sheet component on the sheet component can be set as a process of further stacking another sheet component on the sheet component after stacking the sheet component on the alloy strip bonded to the protective layer. In this case, Figure 2 In the flowchart shown, process (4) is performed after process (7).

[0262] Alternatively, after stacking multiple sheet components, the stack of sheet components can be stacked on an alloy strip bonded to a protective layer. Figure 3 This is a flowchart of the method.

[0263] Figure 3 In the flowchart, the process (4) of the first embodiment is performed after the process (3) of the second embodiment. The description of each process is the same as described above.

[0264] It should be noted that, not only in this case, the steps of stacking alloy strips can be set each time.

[0265] Figure 12 A diagram illustrating the additional magnetic sheet obtained in the second embodiment is shown. Specifically, Figure 12 The magnetic sheet shown is through Figure 3 The process is obtained as shown in the flowchart. Figure 12 As shown in (a), in the magnetic sheet 20c, second laminates 10c1 to 10c3 are stacked on the alloy strip 4' bonded to the protective layer 6. The cracks 9, 9-1, and 9-2 formed in the second laminates 10c1 to 10c3, and the crack 9' formed in the alloy strip 4' bonded to the protective layer 6, are formed at different locations when viewed from the stacking direction. In this way, in this disclosure, external force is directly applied to each alloy strip to form cracks. Therefore, unlike conventional manufacturing methods that simultaneously form cracks in multiple alloy strips, the position of the cracks can be changed in each layer of the alloy strip, thus enabling the production of a magnetic sheet with uniformly formed magnetic gaps. Therefore, even if the magnetic sheet is further punched or cut into a desired shape, the change in permeability due to the processing position is small, enabling the manufacture of a magnetic sheet with stable shielding properties.

[0266] In the magnetic sheet 20c, an additional protective film or layer may be laminated on the surface opposite to the protective layer 6 in the lamination direction. A release film that can be peeled off from the adhesive layer may be used as the protective film in any of the protective layers.

[0267] Next, using Figure 14 An example of a manufacturing apparatus for the magnetic sheet used in the second embodiment will be described. Figure 14 The apparatus for manufacturing the magnetic sheet shown has the same features as... Figure 13 The apparatus for manufacturing the magnetic sheet shown includes the same mechanism. It should be noted that, as a second embodiment, the mechanism... Figure 2 The manufacturing method of the process shown is described.

[0268] • Embodiment of process (1): "The process of bonding an alloy strip to the adhesive layer of a crack adhesive tape having an adhesive layer and a release film that can be peeled off from the adhesive layer"

[0269] First, rollers wound with release film 1E are positioned in three locations. Additionally, rollers wound with adhesive tape 2C for bonding the adhesive layer to release film 1E are also positioned in three locations. Adhesive tape 2C has a two-layer structure consisting of an adhesive layer (5 μm) and release film 1F (25 μm). Release film 1E and release film 1F are made of the same material (PET) with a tensile strength of 3.9 GPa.

[0270] Then, release film 1E and adhesive tape 2C are pulled out from the rollers and bonded together using a pressing roller. The adhesive layer is a substrate film coated on both sides with an acrylic adhesive. Release film 1F can be peeled off from the adhesive layer. Release film 1E can be peeled off after being bonded to the adhesive layer.

[0271] Then, the release film 1F is peeled off from the adhesive layer. In this embodiment, the tape consisting of the adhesive layer and the release film 1E obtained by peeling off the release film 1F is used as a crack tape.

[0272] Then, the alloy strip 4 is pulled out from the roller and bonded to the exposed adhesive layer using a pressing roller. The alloy strip 4 is an alloy strip made of Fe-Cu-Nb-Si-B nanocrystalline alloy (FT-3 manufactured by Hitachi Metals Corporation).

[0273] • Implementation method of process (2) "the process of directly applying external force to the alloy strip to form cracks"

[0274] A crack is formed by directly applying external force to the alloy strip 4, which is adhered to the cracking tape, using a cracking roller 5 with multiple protruding members regularly arranged on its circumferential surface. When forming cracks, a compression roller can be arranged on the release film 1E side to prevent the external force from the cracking roller 5 from escaping.

[0275] • Implementation method of process (3): “the process of peeling the release film from the adhesive layer to form a sheet component having an adhesive layer and an alloy strip with cracks”

[0276] Peel the release film 1E from the adhesive layer of the tape in the crack to expose the adhesive layer. Alternatively, the external force generated on the alloy strip 4 during the peeling of the release film 1E can be used to form a network of cracks.

[0277] • Implementation method of process (5): “The process of bonding alloy strips to an adhesive layer having an adhesive layer and a protective film”

[0278] First, a roller with a protective film 6a1 wound on it is arranged. Furthermore, a roller with an adhesive tape 2C wound on it is arranged near the roller with the protective film 6a1 wound on it. The protective film 6a1 and the adhesive tape 2C are drawn from the roller, and using a pressing roller, the protective film 6a1 is bonded to the adhesive layer of the adhesive tape 2C. The adhesive tape 2C, as described above, has a two-layer structure consisting of an adhesive layer (5 μm) and a release film 1F (25 μm).

[0279] The release film 1F and the protective film 6a1 are made of the same material (PET) with a tensile elasticity of 3.9 GPa. In addition, a substrate film coated with an acrylic adhesive on both sides is used as the adhesive layer.

[0280] Release film 1F can be peeled off from the adhesive layer. Protective film 6a1 can be peeled off after being bonded to the adhesive layer.

[0281] Then, the release film 1F is peeled off from the tape 2C. In this embodiment, the tape thus obtained, consisting of an adhesive layer and a protective film 6a1, is used as the protective layer.

[0282] Then, the alloy strip 4' is pulled out from the roller and bonded to the exposed adhesive layer using a pressing roller. The alloy strip 4' can be made of the same material as the alloy strip 4, or it can be made of a different material.

[0283] • Implementation method of process (6): “The process of directly applying external force to the alloy strip bonded to the protective layer to form cracks”

[0284] A cracking roller 5, with multiple protruding members regularly arranged on its circumferential surface, directly applies external force to the alloy strip 4' bonded to the protective layer 6a1, causing cracks to form. At this time, a compression roller can be arranged on the protective film 6a1 side to prevent the external force from the cracking roller from escaping.

[0285] • Implementation method of process (7) "Laying sheet components on alloy strips bonded to a protective layer"

[0286] Sheet components manufactured through processes (1) to (3) are stacked on an alloy strip 4' of an adhesive layer bonded to a protective layer.

[0287] In this embodiment, one sheet component is first bonded to the alloy strip 4' bonded to the protective layer, and then two more sheet components are stacked in sequence.

[0288] It should be noted that in this second embodiment, in the lamination direction, a protective film 6a2 (10 μm thick) is adhered to the end face opposite to the end face to which the protective film 6a1 is adhered.

[0289] The tape 2C is bonded to the magnetic sheet obtained in step (7). Then, the release film 1F is peeled off from the tape 2C to obtain the magnetic sheet with an adhesive layer for forming a protective film on the outermost layer. Then, the protective film 6a2 is bonded to the adhesive layer.

[0290] It should be noted that protective films 6a1 and 6a2 can also be used as peelable films after the adhesive layer is bonded to the protective layer. In this case, the adhesive layer of the protective layer, exposed by peeling off the protective film, can be bonded to the electronic device to which magnetic shielding is performed.

[0291] In the second embodiment, after the protective film 6a2 is laminated, the magnetic sheet is cut to the necessary size using a cutter 7 and conveyed to the tray 8. Alternatively, instead of the cutter 7, it can be processed into the desired shape by punching.

[0292] Figure 16 This is a cross-sectional photograph showing an example of a magnetic sheet obtained by the manufacturing method of the alloy strip laminate involved in this disclosure. In the photograph, the white portion is the alloy strip, and the gray portion between the alloy strips is the adhesive layer. In addition, there is an adhesive layer or protective layer for the sheet member on the outer side closer to the lamination direction than the four alloy strips.

[0293] Cracks or fissures can be observed in the first to third layers of the alloy strips from the bottom, indicating the presence of magnetic gaps. Furthermore, the surfaces of all the alloy strips are substantially free of unevenness (no protruding three-dimensional structures), and the planarity of the alloy strips is excellent. Additionally, the planarity of the magnetic sheet, which is a four-layer stack, is also excellent.

[0294] Figure 18 This is a cross-sectional photograph of a magnetic sheet obtained using a conventional manufacturing method (a method in which multiple alloy strips are stacked and then subjected to external force to form cracks). In conventional magnetic sheets, the alloy strips are deformed in an undulating manner, and the adhesive layer and the protective layer at the ends are also deformed in the same undulating manner.

[0295] Figure 17 This is a cross-sectional photograph of a magnetic sheet obtained using conventional manufacturing methods. Specifically, Figure 17 The magnetic sheet shown is made using a flat, plate-like component. Figure 18 The magnetic sheet is formed by pressing and flattening both sides. Figure 17In the magnetic sheet, with Figure 18 Compared to magnetic sheets, the alloy strips are arranged more flatly, so in the lower center of the image, the bottommost alloy strip forms a double structure, creating a three-dimensional structure with a protruding surface.

[0296] Figure 19 A graph showing the change in permeability during placement after the manufacture of a conventional magnetic sheet is presented. Specifically, Figure 19 This graph shows the rate of change of the relative permeability of a magnetic sheet after it has been manufactured (set to 0 hours) over 1000 hours in an atmosphere at 70°C, compared to the value at 0 hours. Figure 19 In the figure, (a) is a graph showing the real part (real part) μr' of the AC relative permeability μr, and (b) is a graph showing the imaginary part (imaginary part) μr'' of the AC relative permeability μr. Figure 19 The measurement shown used a magnetic sheet manufactured using a conventional manufacturing method (a method that involves applying external force to form cracks after stacking multiple alloy strips).

[0297] In the determination of the relative permeability μr of AC circuit, an impedance analyzer (Keysight Technologies E4990A, measuring fixture: 16454A) was used. The OSC level was set to 0.03V, and the impedance (Z) and the inductance (L) of the series equivalent circuit were measured at a frequency of 128kHz at a temperature of 25°C. S The relative permeability μr of AC magnetic flux is calculated based on the following formula. The evaluation sample is obtained by stacking 10 to 20 layers of ring-shaped sheets with an outer diameter of 20 mm and an inner diameter of 9 mm.

[0298] μr=2π×Z / (2π×μ0×f×t×n×ln(OD / ID))

[0299] Z: Absolute value of impedance

[0300] f: Frequency (Hz)

[0301] t: Strip thickness (m)

[0302] n: number of layers

[0303] μ0: Vacuum permeability (4×π×10⁻⁶) -7 H / m)

[0304] OD: Outer Diameter (m)

[0305] ID: inner diameter (m)

[0306] like Figure 19 As shown, in magnetic sheets obtained by conventional manufacturing methods, the alternating relative permeability μr changes significantly over time.

[0307] [Contactless charging device]

[0308] As an example of using the magnetic sheet of this disclosure, an example of a contactless charging device is given. The contactless charging device, for example, has... Figure 20 The circuit configuration shown is as follows. The power supply device 200 includes: a power supply section 21 supplying alternating current; a rectifier circuit 22 connected to the power supply section 21 for rectifying the alternating current into direct current; a switching circuit 23 that inputs direct current and converts it into a high-frequency current of a predetermined frequency; a primary coil 201 connected to the switching circuit 23 to carry the high-frequency current; a resonant capacitor 26 connected in parallel with the primary coil 201 in a manner resonating with the switching circuit 23 at the same frequency; a control circuit 24 connected to the switching circuit 23; and a control primary coil 25 connected to the control circuit 24. The control circuit 24 controls the operation of the switching circuit 23 based on the induced current obtained from the control primary coil 25.

[0309] The power receiving device 300 includes: a secondary coil 301 that receives magnetic flux generated from a primary coil 201; a rectifier circuit 32 connected to the secondary coil 301; a secondary battery 33 connected to the rectifier circuit 32; a battery control circuit 34 connected to the secondary battery 33 for detecting the charge storage status based on the voltage of the secondary battery 33; and a control secondary coil 35 connected to the battery control circuit 34. A resonant capacitor (not shown) can be connected in parallel to the secondary coil 301. The rectified current is used not only for storing energy in the secondary battery 33, but also for electronic circuits and drive components (not shown). The battery control circuit 34 causes a signal for optimal charging to flow through the control secondary coil 35 based on the charge storage status of the secondary battery 33. For example, when the secondary battery 33 is fully charged, this signal flows through the control secondary coil 35 and is transmitted to the control circuit 24 of the power supply device 200 via the primary control coil 25, which is electromagnetically coupled to the control secondary coil 35. The control circuit 24 stops the switching circuit 23 based on this signal.

[0310] The magnetic sheet of this disclosure is used in power supply devices, for example, between primary coil 201 and electronic components of other power supply devices, and between primary control coil 25 and electronic components of other power supply devices. The magnetic sheet of this disclosure is also used in power receiving devices, for example, between secondary coil 301 and electronic components of other power supply devices, and between secondary control coil 35 and electronic components of other power supply devices.

[0311] Example

[0312] The present disclosure will be described in detail below through embodiments. However, the present disclosure is not limited to the following embodiments.

[0313] <Example 1>

[0314] Use with Figure 13 The apparatus for manufacturing the components shown produces a magnetic sheet. The method for manufacturing the magnetic sheet (including conditions and materials) is the same as in the first embodiment described above. Specific conditions and materials are shown below.

[0315] ·Alloy strip: FT-3 (manufactured by Hitachi Metals Co., Ltd.)

[0316] • Thickness of the alloy strip: 16μm

[0317] • Width of alloy strip: 60mm

[0318] • Number of layers: 4 pieces

[0319] • Pressure of the crushing roller: 0.3 MPa

[0320] • Magnetic sheet size: 50mm × 50mm

[0321] <Example 2>

[0322] The magnetic sheet was made in the same order as in Example 1.

[0323] <Evaluation>

[0324] The AC relative permeability μr (128 kHz) of the magnetic sheet was evaluated. The evaluation results are shown in Table 1.

[0325] [Table 1]

[0326]

[0327] As shown in Table 1, in Examples 1 and 2, the change rate after 300 days (7200 hours) was within ±3.0%. In contrast, the change rate of the magnetic sheets produced by conventional manufacturing methods (where four layers of alloy strips, separated by an adhesive layer, are sandwiched between two resin films, and an external force is applied from above the resin films to create cracks) was 7% to 10% after 100 hours. These results indicate that Examples 1 and 2 yielded magnetic sheets with minimal change in permeability.

[0328] The disclosures of Japanese Patent Application No. 2019-095278, filed on May 21, 2019, and Japanese Patent Application No. 2019-095279, filed on May 21, 2019, are incorporated herein by reference in their entirety. All documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as the specific and separately described cases.

Claims

1. A magnetic sheet, which is formed by stacking multiple alloy strips through adhesive layers. The alloy strip contains multiple linear cracks that are regularly formed. The linear cracks are arranged in a first direction and spaced apart in the first direction and in directions orthogonal to the first direction.

2. The magnetic sheet according to claim 1, having a network of slits connecting the plurality of said linear slits.

3. The magnetic sheet according to claim 1 or 2, When viewed from the stacking direction of the plurality of alloy strips, the location of the linear cracks formed in the first alloy strip is different from the location of the linear cracks formed in the second alloy strip stacked on the first alloy strip.

4. The magnetic sheet according to claim 3, When viewed from the stacking direction of the plurality of alloy strips, the location of the linear cracks formed in the third alloy strip stacked on the second alloy strip is different from the location of the linear cracks formed in the first alloy strip and the second alloy strip.

5. The magnetic sheet according to claim 1 or 2, wherein the alloy ribbon is a nanocrystalline alloy ribbon.

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