Laminate and method for manufacturing the same

Abstract

To provide a laminate that enhances an electromagnetic wave shielding effect in a low-frequency region.SOLUTION: A laminate includes one or more non-magnetic metal layers and one or more magnetic metal layers, where at least one magnetic metal layer includes an amorphous phase.SELECTED DRAWING: Figure 1A

Description

[Technical Field]

[0001] The present invention relates to a laminate, and more particularly to a laminate that can constitute an electromagnetic wave shielding material used as a covering or exterior material for electric and electronic devices. [Background technology]

[0002] In recent years, interest in global environmental issues has grown worldwide, and environmentally friendly vehicles equipped with secondary batteries, such as electric vehicles and hybrid vehicles, are becoming increasingly popular. Many of these vehicles use a system in which direct current (DC) generated by the onboard secondary battery is converted to alternating current (AC) via an inverter, and the necessary power is then supplied to an AC motor to generate driving force. Electromagnetic waves are generated due to the switching operation of the inverter, etc. Because electromagnetic waves can interfere with reception of onboard audio equipment, wireless devices, and the like, measures have been taken to shield electromagnetic waves by housing the inverter, or the inverter together with the battery and motor, etc., in a metal case (Patent Document 1: JP 2003-285002 A).

[0003] Electromagnetic waves are emitted not only from automobiles but also from many other electrical and electronic devices, including communication devices, displays, and medical devices. Electromagnetic waves can cause precision equipment to malfunction, and there are also concerns about their effects on the human body. For this reason, various technologies have been developed to mitigate the effects of electromagnetic waves using electromagnetic wave shielding materials. For example, copper foil composites (laminates) formed by laminating copper foil and resin films are used as electromagnetic wave shielding materials (Patent Document 2: Japanese Patent Laid-Open Publication No. 7-290449). Copper foil has an electromagnetic wave shielding effect, and a resin film is laminated on the copper foil to reinforce it. Another known electromagnetic wave shielding structure has metal layers laminated on both the inside and outside of an intermediate layer made of an insulating material (Patent Document 3: Japanese Patent No. 4602680). Also known is an optical element for blocking electromagnetic waves, which comprises a base substrate and a laminated member formed on one surface of the base substrate and composed of multiple repeating unit films including a metal layer and a high refractive index layer (niobium pentoxide) (Patent Document 4: JP 2008-21979 A).

[0004] Furthermore, in recent years, the miniaturization and high efficiency of electrical and electronic devices have led to an ever-increasing demand for electromagnetic wave shielding effectiveness. In particular, electrical and electronic devices related to power supplies and drives, such as inverters around the motors of electric vehicles, often generate strong magnetic field noise in the low-frequency range (typically in the frequency range of 1 MHz or less). Therefore, electromagnetic wave shielding materials that provide a higher electromagnetic wave shielding effectiveness are needed.

[0005] One method for significantly improving the electromagnetic wave shielding effect is disclosed in Japanese Patent No. 6278922 (Patent Document 5). This document proposes an electromagnetic wave shielding material having a structure in which at least three metal foils are laminated with an insulating layer interposed therebetween. It has been shown that this electromagnetic wave shielding material, by laminating three or more metal foils, significantly improves the shielding effect compared to a single metal foil or a two-layer metal foil, even if the total thickness of the metal foils is the same. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-285002 [Patent Document 2] Japanese Patent Application Publication No. 7-290449 [Patent Document 3] Patent No. 4602680 [Patent Document 4] Japanese Patent Application Laid-Open No. 2008-21979 [Patent Document 5] Patent No. 6278922 Summary of the Invention [Problem to be solved by the invention]

[0007] The method disclosed in Patent Document 5 improved the overall electromagnetic wave shielding effect, but only limited the improvement in the shielding effect against magnetic field noise in the low frequency range. The inventors investigated the cause and found that the metal foil materials conventionally used in electromagnetic wave shielding materials themselves have a low shielding effect against magnetic field noise in the low frequency range. Therefore, there is a need for the development of new materials that can reduce magnetic field noise not only in the mid- to high-frequency range, but also in the low frequency range.

[0008] Furthermore, electromagnetic shielding materials may require forming processes such as drawing and bending to conform to the shape of the electrical and electronic devices to which they are applied. Generally, the metal foils used in electromagnetic shielding materials range in thickness from a few microns to a few tens of microns, making them prone to cracking during forming. Therefore, if forming is required, it is important to prevent the electromagnetic shielding material from cracking during the forming process. Therefore, if new materials with improved formability could be provided to accommodate various forming processes, by processing the new materials into appropriate shapes, they could provide electromagnetic shielding effects (especially reducing magnetic field noise in the low-frequency range) for a wider range of electrical and electronic devices.

[0009] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide, in one embodiment, a laminate that improves electromagnetic wave shielding effect in the low frequency range while maintaining electromagnetic wave shielding effect against magnetic field noise in the mid- to high-frequency range. In another embodiment, an object of the present invention is to provide a method for manufacturing such a laminate. [Means for solving the problem]

[0010] As described above, the inventors discovered that conventional materials lack the shielding effect against magnetic field noise in the low-frequency range. Therefore, as a result of extensive research, the inventors discovered that a laminate made by laminating a nonmagnetic metal and an amorphous magnetic metal with a low degree of crystallinity has a high electromagnetic wave shielding effect over a wide frequency range, from low to high frequencies. Furthermore, when the inventors molded this laminate into a predetermined shape, they found that cracks occurring in the laminate could be effectively reduced. Furthermore, they discovered that the electromagnetic wave shielding effect in the low-frequency range could be further improved by partially or completely crystallizing the magnetic metal layer containing the amorphous magnetic metal.

[0011] The present invention has been completed based on the above findings, and is exemplified below.

[0012] [1] A laminate comprising at least one non-magnetic metal layer and at least one magnetic metal layer, at least one of the magnetic metal layers containing an amorphous phase. [2] The laminate according to [1], wherein the degree of crystallinity of the magnetic metal layer containing the amorphous phase is 10% or more. [3] The laminate according to [1] or [2], wherein at least a portion of the laminate is molded. [4] The laminate according to any one of [1] to [3], wherein the nonmagnetic metal layer has a thickness of 4 to 100 μm. [5] The laminate according to any one of [1] to [4], wherein the magnetic metal layer has a thickness of 4 to 100 μm. [6] The laminate according to any one of [1] to [5], wherein the total thickness of the nonmagnetic metal layer and the magnetic metal layer is 15 to 150 μm. [7] The laminate according to any one of [1] to [6], wherein the non-magnetic metal layer is selected from the group consisting of aluminum foil, aluminum alloy foil, copper foil, and copper alloy foil. [8] The laminate according to any one of [1] to [7], wherein in the magnetic metal layer containing the amorphous phase, the total amount of Fe, Ni, and Co is 65.0 to 90.0 atomic %, the amount of Cu is 0 to 2.0 atomic %, the total amount of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Ag, Zn, Al, Sn, As, Sb, Bi, and REM is 0 to 8.0 atomic %, and the remainder is at least one element selected from the group consisting of B, Si, P, and C, and impurities, and the total amount of Fe, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Co, Ni, Ag, Zn, Al, Sn, As, Sb, Bi, and REM is 65.0 to 90.0 atomic %. [9] The laminate according to any one of [1] to [7], wherein in the magnetic metal layer containing the amorphous phase, the total amount of Fe, Ni, and Co is 65.0 to 92.0 atomic %, the amount of Cu is 0 to 2.0 atomic %, the total amount of Ti, V, Ta, Cr, Mo, W, Mn, Ag, Zn, Al, Sn, As, Sb, Bi, and REM is 0 to 8.0 atomic %, the total amount of B, Si, P, and C is 0 to 10.0 atomic %, and the remainder is at least one selected from the group consisting of Zr, Hf, and Nb, and impurities.

[10] In the magnetic metal layer containing the amorphous phase, the amount of Fe is 79.0 to 88.0 atomic %, the amount of B is 5.0 to 15.0 atomic %, the amount of Si is 0 to 8.0 atomic %, the amount of P is 1.0 to 8.0 atomic %, the amount of C is 0 to 5.0 atomic %, the amount of Cu is 0 to 1.4 atomic %, and the total amount of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Ag, Zn, Al, Sn, As, Sb, Bi and REM is 0 to 8.0 atomic %. The laminate according to any one of [1] to [7], wherein the total amount of Fe, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Co, Ni, Ag, Zn, Al, Sn, As, Sb, Bi, and REM is 79.0 to 88.0 atomic %, and the total amount of Fe, B, Si, P, C, Cu, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Co, Ni, Ag, Zn, Al, Sn, As, Sb, Bi, and REM is 100%.

[11] The conductivity of the non-magnetic metal layer is 30.0×10 6 The laminate according to any one of [1] to

[10] , wherein the saturation magnetic flux density of the magnetic metal layer containing the amorphous phase is 1.50 T or more.

[12] The laminate according to any one of [1] to

[11] , wherein at least one of the non-magnetic metal layers is in contact with at least one of the magnetic metal layers containing an amorphous phase.

[13] A method for manufacturing a laminate, comprising a lamination step of laminating materials containing a non-magnetic metal and an amorphous magnetic metal to form a green laminate.

[14] The method for manufacturing a laminate according to

[13] , further comprising a firing step of firing the green laminate so that the crystallinity of the amorphous magnetic metal layer of the green laminate is 10% or more.

[15] The method for producing a laminate according to

[14] , further comprising a forming step of processing the unfired laminate into a predetermined shape before the firing step.

[16]

[15] The method for producing a laminate according to

[15] , further comprising a pre-firing step of pre-firing the unsintered laminate before the molding step so that the crystallinity of the amorphous magnetic metal in the unsintered laminate is 10 to 75%.

[17] The method for producing a laminate according to any one of

[13] to

[16] , wherein in the laminating step, the non-magnetic metal and the amorphous magnetic metal are bonded by a surface activated bonding method. [Effects of the Invention]

[0013] According to one embodiment of the present invention, it is possible to provide a laminate that improves the electromagnetic wave shielding effect in the low frequency range while maintaining the electromagnetic wave shielding effect against magnetic field noise in the mid- to high-frequency range. As a result, it is possible to significantly reduce noise entering electric and electronic devices. It is also possible to reduce the weight and size of electric and electronic devices. Furthermore, according to another embodiment of the present invention, it is possible to provide a method for producing such a laminate. [Brief explanation of the drawings]

[0014] [Figure 1A] 1 is an example of a laminate according to an embodiment of the present invention. [Figure 1B] 1 is an example of a laminate according to an embodiment of the present invention. [Figure 1C] 1 is an example of a laminate according to an embodiment of the present invention. [Figure 1D] 1 is an example of a laminate according to an embodiment of the present invention. [Figure 1E] 1 is an example of a laminate according to an embodiment of the present invention. [Figure 1F] 1 is an example of a laminate according to an embodiment of the present invention. [Figure 1G] 1 is an example of a laminate according to an embodiment of the present invention. [Figure 1H] 1 is an example of a laminate according to an embodiment of the present invention. [Figure 2] 1 is an example of the relationship between crystallinity and saturation magnetic flux density. [Figure 3] 10 is a flowchart of a method for manufacturing a laminate according to another embodiment of the present invention. [Figure 4A] FIG. 10 is a diagram showing a laminate in which cracks occurred after molding (a defective result). [Figure 4B] FIG. 10 is a diagram showing a laminate in which no cracks occurred after molding (good result). DETAILED DESCRIPTION OF THE INVENTION

[0015] Next, embodiments of the present invention will be described in detail. It should be understood that the present invention is not limited to the following embodiments, and that appropriate design changes and improvements may be made based on the ordinary knowledge of those skilled in the art without departing from the spirit of the present invention.

[0016] (1. Laminate) As shown in FIG. 1A, a laminate 1 according to one embodiment of the present invention includes a nonmagnetic metal layer 2 and a magnetic metal layer 3, and the magnetic metal layer 3 includes an amorphous phase. The laminate 1 can adequately shield electromagnetic waves over a wide frequency band, from low to high frequencies. The nonmagnetic metal layer 2 may be a single metal layer as shown in FIG. 1A, or multiple metal layers as shown in FIG. 1B. Similarly, the magnetic metal layer 3 may be a single metal layer as shown in FIG. 1A, or multiple metal layers as shown in FIG. 1C. The number of nonmagnetic metal layers 2 may be at least one, or multiple layers may be present depending on the number of other layers, as shown in FIGS. 1D and 1E. When the laminate 1 includes multiple nonmagnetic metal layers 2, the nonmagnetic metal layers 2 may have the same or different configurations. Similarly, the number of magnetic metal layers 3 may be at least one, or multiple layers may be present depending on the number of other layers, as shown in FIG. 1E. When the laminate 1 includes multiple magnetic metal layers 3, the magnetic metal layers 3 may have the same or different configurations. As shown in FIG. 1F, the laminate 1 may include a non-metallic layer 4. This non-metallic layer 4 may be a single non-metallic layer, or may be multiple non-metallic layers as shown in FIG. 1G. The non-metallic layer 4 may be a single layer, as shown in FIG. 1F, or multiple layers depending on the number of other layers, as shown in FIG. 1H. When the laminate 1 includes multiple non-metallic layers 4, the non-metallic layers 4 may have the same configuration or different configurations.

[0017] To improve the electromagnetic wave shielding effect, the total thickness of the nonmagnetic metal layer 2 and the magnetic metal layer 3 is preferably 15 μm or more. To improve moldability, this total thickness is preferably 150 μm or less, more preferably 120 μm or less, even more preferably 80 μm or less, and most preferably 60 μm or less. Therefore, the thickness of the laminate 1 may be 15 to 150 μm.

[0018] From a cost perspective, the number of nonmagnetic metal layers 2 may be one. On the other hand, even if the total thickness of the nonmagnetic metal layers 2 is the same, if the laminate 1 has a structure in which a magnetic metal layer 3 is present between the nonmagnetic metal layers 2, the electromagnetic wave shielding effect of the laminate 1 is enhanced due to the synergistic effect of the two layers on the electromagnetic wave shielding effect. In addition, the number of surfaces from which electromagnetic waves are reflected (contact surfaces between different materials within the layer) can be increased, thereby increasing the number of times the electromagnetic wave is reflected and attenuating it. Therefore, for the same electromagnetic wave shielding effect, the thickness of the laminate 1 can be reduced. Therefore, it is preferable to have two or more nonmagnetic metal layers 2. From a cost perspective, the number of nonmagnetic metal layers 2 is preferably five or less, more preferably four or less, and most preferably three or less.

[0019] Similarly, from a cost perspective, the number of magnetic metal layers 3 may be one. On the other hand, even if the total thickness of the magnetic metal layers 3 is the same, if the laminate 1 has a structure in which a non-magnetic metal layer 2 is present between the magnetic metal layers 3, the two layers have a synergistic effect on the electromagnetic wave shielding effect (for example, when the magnetic flux density in the magnetic material fluctuates, eddy currents are formed outside the magnetic flux concentration area, more reliably capturing the magnetic flux and preventing the generated electric field fluctuations from leaking outside the shield), thereby enhancing the electromagnetic wave shielding effect of the laminate 1. In addition, the number of surfaces from which electromagnetic waves are reflected (contact surfaces between different materials within the layer) can be increased, thereby increasing the number of times the electromagnetic wave is reflected and attenuating it. Therefore, for the same electromagnetic wave shielding effect, the thickness of the laminate 1 can be reduced. Therefore, it is preferable to have two or more magnetic metal layers 3. From a cost perspective, the number of magnetic metal layers 3 is preferably five or less, more preferably four or less, and most preferably three or less.

[0020] To facilitate earth connection, it is preferable that the non-magnetic metal layer 2 and the magnetic metal layer 3 containing an amorphous phase are in contact with each other, and it is more preferable that the non-magnetic metal layer 2 and the magnetic metal layer 3 are in contact with each other entirely. In other words, it is preferable that the non-magnetic metal layer 2 and the magnetic metal layer 3 are stacked so as to be alternately arranged. In particular, it is preferable that the non-magnetic metal layer 2 and the magnetic metal layer 3 are stacked so as to be alternately arranged. 6 It is preferable that the non-magnetic metal layer 2 containing a metal having a conductivity of S / m or more and the magnetic metal layer 3 containing an amorphous phase are in contact with each other.

[0021] In this specification, the nonmagnetic metal layer 2 is defined as a metal layer having a volume magnetic susceptibility in SI units of -1.0 to 1.0 at 20°C, and this can be confirmed by the fact that it is not attracted to a typical ferrite magnet when brought close to it. Examples of such metals include copper (Cu), aluminum (Al), silver (Ag), gold (Au), tin (Sn), zinc (Zn), and alloys containing these elements as the main component (e.g., copper alloys). These materials typically have a relative magnetic permeability of around 1 (0.9 to 1.1).

[0022] From the viewpoint of enhancing the shielding effect of the laminate 1 against AC magnetic fields and AC electric fields, it is preferable that the metal contained in the nonmagnetic metal layer 2 has high electrical conductivity. Specifically, the electrical conductivity at 20° C. is 1.0×10 6 S / m or more is preferable, and 10.0 × 10 6 S / m or more is more preferable, and 30.0×10 6 S / m or more is more preferable, and 50.0×10 6 It is most preferable that the conductivity of such a metal is about 33.0×10 S / m or more. 6 S / m of aluminum, conductivity is approximately 58.0 x 10 6 S / m of copper, conductivity is approximately 61.4 x 10 6 Examples of suitable materials include silver with a conductivity of 1000 S / m. The non-magnetic metal layer 2 can be in various forms such as metal foil, plating, paste, sputtering, etc., but metal foil is easy to use in practice. Considering both conductivity and cost, it is practically preferable for the laminate to contain aluminum or copper (e.g., aluminum foil, aluminum alloy foil, copper foil, and copper alloy foil). It is particularly preferable for the non-magnetic metal layer 2 to contain copper. The upper limit of conductivity is 200×10 6 The electrical conductivity may be S / m. The electrical conductivity is determined by the four-terminal method specified in JIS H0505 (1975).

[0023] When the nonmagnetic metal layer 2 contains copper foil, the higher the purity of the copper, the more the electromagnetic wave shielding effect of the laminate 1 improves. Therefore, the purity of copper is preferably 99.5% by mass or more, and more preferably 99.8% by mass or more. The purity of copper may be 100% by mass or less. Furthermore, to improve the elongation of the copper foil, the copper foil may contain at least one element selected from the group consisting of phosphorus (P), Sn, manganese (Mn), chromium (Cr), Zn, zirconium (Zr), magnesium (Mg), nickel (Ni), silicon (Si), and Ag as an optional element. When the copper foil contains P, the amount of P is preferably 50 ppm by mass, and more preferably 10 to 50 ppm by mass. When the copper foil contains at least one element selected from the group consisting of Sn, Mn, Cr, Zn, Zr, Mg, Ni, Si, and Ag, the total amount of these elements is preferably 2000 ppm by mass or less, and more preferably 200 to 2000 ppm by mass. For example, the copper foil is composed of 99.5% by mass or 99.8% by mass of copper, with the remainder consisting of the above-mentioned optional elements and impurities. The copper foil may be any of rolled copper foil, electrolytic copper foil, and metallized copper foil. Rolled copper foil is preferable because it has excellent formability (particularly, flexibility and drawability).

[0024] When copper foil is used as the non-magnetic metal layer 2, if the copper foil is sufficiently thick, the strength and ductility of the non-magnetic metal layer 2 will be sufficiently high, thereby improving the formability of the laminate 1. Therefore, the thickness of the non-magnetic metal layer 2 is preferably 4 μm or more. Furthermore, if the non-magnetic metal layer 2 is thick, the electromagnetic wave shielding effect of the non-magnetic metal layer 2 will be increased. Therefore, the thickness of the non-magnetic metal layer 2 is more preferably 6 μm or more, more preferably 8 μm or more, and even more preferably 10 μm or more. If the thickness of the non-magnetic metal layer 2 is sufficiently small, the strength of the non-magnetic metal layer 2 will be sufficiently low, thereby sufficiently improving the formability of the laminate 1. Therefore, the thickness of the non-magnetic metal layer 2 is preferably 100 μm or less, more preferably 50 μm or less, even more preferably 45 μm or less, and most preferably 40 μm or less. When the laminate 1 includes multiple non-magnetic metal layers 2, one non-magnetic metal layer 2 may be within the above-mentioned thickness range, some of the non-magnetic metal layers 2 may be within the above-mentioned thickness range, or all of the non-magnetic metal layers 2 may be within the above-mentioned thickness range.

[0025] To improve environmental resistance such as heat resistance and corrosion resistance, the non-magnetic metal layer 2 may contain one or more of Au, Ag, Sn, Zn, or alloys containing these enumerated elements as a main component (for example, Sn alloys include Sn—Ag alloys, Sn—Ni alloys, and Sn—Cu alloys). The enumerated elements and their alloys are preferably present on the outermost surface of the laminate 1. From the viewpoint of cost reduction, the non-magnetic metal layer 2 preferably contains Sn or an Sn alloy. Furthermore, the non-magnetic metal layer 2 may have irregularities to improve adhesion between layers. The irregularities can be formed, for example, by a roughening treatment described below. The laminate 1 may include a non-magnetic metal layer 2 consisting only of the enumerated elements and their alloys, and the thickness of this non-magnetic metal layer 2 is preferably 0.001 to 10 μm.

[0026] In this specification, the magnetic metal layer 3 is defined as a layer of metal having a volume magnetic susceptibility of 10 or more in SI units at 20°C, and can be confirmed by the fact that when a general ferrite magnet is brought close to it, it is attracted to the ferrite magnet. Examples of such metals include iron (Fe), nickel (Ni), cobalt (Co), and alloys containing these listed elements as the main component (e.g., iron alloys such as Fe-Ni). These materials usually have a relative magnetic permeability that is sufficiently larger than 1 (e.g., 5 to 10 6 ).

[0027] Furthermore, at least one of the magnetic metal layers 3 contains an amorphous phase. An amorphous phase is a phase without a clear crystalline structure. A magnetic metal layer 3 is determined to contain an amorphous phase when a broad, circular electron diffraction pattern is obtained using a transmission electron microscope. In particular, when the amorphous phase is abundant, in addition to obtaining the electron diffraction pattern described above, it can be easily identified as a broad peak using the X-ray diffraction method described below, which can replace obtaining a diffraction pattern using a transmission electron microscope. Examples of magnetic metal layers 3 containing an amorphous phase include amorphous metals containing only an amorphous phase or nanocrystalline metals in which a crystalline phase is dispersed within an amorphous phase. Such magnetic metal layers 3 can control the magnetic anisotropy to a very small value in the region corresponding to the width of the domain wall, effectively dispersing magnetic field lines within the plane of the magnetic metal layer 3, allowing the entire magnetic metal layer 3 to be used as a shield against magnetic fields. This effectively reduces low-frequency magnetic field noise and contributes to reducing the weight of the laminate 1. In addition, since typical thin magnetic metals have macroscopic directionality, it is possible that the magnetic permeability of the magnetic metal is not fully utilized.

[0028] From the viewpoint of enhancing the electromagnetic shielding effect of the laminate 1 against DC magnetic fields and low-frequency magnetic field noise without increasing the dimensions of the laminate 1 (from the viewpoint of using the product near the optimal operating point), it is preferable that the metal contained in the magnetic metal layer 3 has a high saturation magnetic flux density and a high relative magnetic permeability. Specifically, the saturation magnetic flux density at 20°C is preferably 0.50 T or more, more preferably 1.00 T or more, more preferably 1.50 T or more, even more preferably 1.60 T or more, and most preferably 1.70 T or more. The upper limit of the saturation magnetic flux density may be 2.50 T. This saturation magnetic flux density is measured using a vibrating sample magnetometer (VSM). Furthermore, for the metal contained in the laminate 1 or the magnetic metal layer 3, the maximum differential relative magnetic permeability at 20°C is preferably 1000 or more, more preferably 2000 or more, and most preferably 5000 or more. The upper limit of the differential relative magnetic permeability is 1.0 × 10 6 In this specification, the differential relative permeability is a value (10 7 ) multiplied by . / 4π. This differential relative permeability is measured using a BH tracer. The maximum differential relative permeability is defined as the average value of the maximum differential relative permeability in a predetermined direction (first differential relative permeability) and the differential relative permeability in a direction perpendicular to this predetermined direction (second differential relative permeability). Furthermore, in standard applications, it is important that the magnetic properties do not have directionality (anisotropy), since there is no need to apply product design according to the electromagnetic wave environment. Therefore, it is desirable that the maximum values ​​of the first differential relative permeability and the second differential relative permeability be equal. For example, the value obtained by dividing the maximum value of the first differential relative permeability by the maximum value of the second differential relative permeability is preferably 0.90 to 1.10, more preferably 0.95 to 1.05, and most preferably 0.98 to 1.02. Furthermore, for example, the value obtained by dividing the difference between the maximum value of the first differential relative magnetic permeability and the maximum value of the second differential relative magnetic permeability by the maximum value of the differential relative magnetic permeability is preferably 0.10 or less, more preferably 0.08 or less, and most preferably 0.05 or less.

[0029] If the magnetic metal layer 3 contains a small-sized metal crystalline phase (crystal grains) in addition to the amorphous phase, the saturation magnetic flux density can be increased without increasing the magnetic anisotropy or coercive force. The average crystal grain size of these crystal grains is preferably 60 nm or less, more preferably 30 nm or less, even more preferably 25 nm or less, even more preferably 20 nm or less, and most preferably 15 nm or less. This average crystal grain size may be 3 nm or more. This average crystal grain size is determined by analyzing the main peak of metal crystals in a spectrum obtained by X-ray diffraction (XRD) using the Scherrer method. The Scherrer constant in this Scherrer method is 0.90.

[0030] Furthermore, as shown in FIG. 2 as an example of a material having a specific chemical composition (chemical composition of the example) and a coercive force of 10 A / m or less, the saturation magnetic flux density increases as the amount of metal crystalline phase increases. Therefore, it is desirable to increase the amount of metal crystalline phase to the maximum amount of available metal crystalline phase. If crystallinity is defined as the amount of metal crystalline phase relative to the maximum amount of available metal crystalline phase, this crystallinity is preferably 10% or more, more preferably 20% or more, more preferably 30% or more, more preferably 40% or more, more preferably 50% or more, even more preferably 60% or more, even more preferably 80% or more, and most preferably 90% or more. This crystallinity may be 100% or less. On the other hand, if the crystallinity is high, the magnetic metal layer 3 becomes brittle and the moldability of the laminate 1 decreases. Therefore, if molding is required, the crystallinity before molding is preferably 75% or less, more preferably 60% or less. Considering the balance between saturation magnetic flux density and moldability, the crystallinity is preferably 10 to 75%, and most preferably 40 to 60%. Typical thin magnetic metals are brittle and prone to cracking during molding. If cracks occur, the laminate 1's effectiveness in reducing magnetic field noise also decreases. In this case, magnetic field noise may leak through the cracks. The crystallinity is determined by a differential scanning calorimeter (DSC). In this DSC measurement, the calorific value (calculated from the peak area) resulting from the formation of the metal crystalline phase in the DSC curve obtained from a material in which the metal crystalline phase ratio (described below) on both sides of the material is 1% or less (e.g., a material after liquid quenching and before crystallization) is defined as the total calorific value ΔH(all) (i.e., 100%). Similarly, the calorific value (calculated from the peak area) resulting from the formation of the metal crystalline phase in the DSC curve obtained from the material being measured is defined as the residual calorific value ΔH(bal). The degree of crystallinity can be obtained by subtracting the residual heat generation amount ΔH(bal) from the total heat generation amount ΔH(all), dividing the result by the total heat generation amount ΔH(all), and multiplying the result by 100 (i.e., the degree of crystallinity is calculated by (ΔH(all)-ΔH(bal)) / ΔH(all)×100).If a peak due to the formation of a metal crystalline phase overlaps with a peak due to a phase other than the metal phase, such as a compound phase, peak separation is performed to identify the peak due to the formation of the metal crystalline phase. The metal crystalline phase fraction is defined as the proportion of the metal crystalline phase relative to all phases at the main position where a broad peak due to the amorphous phase is obtained. This metal crystalline phase fraction is determined by the method for determining crystallinity disclosed in International Publication No. 2017 / 022594 using a spectrum obtained by XRD (i.e., the value of X in this International Publication is defined as the metal crystalline phase fraction). In this XRD, if both sides can be measured, it is defined as the average value of both sides. If only one side can be measured, it is defined on that one side. If the surface cannot be measured, it is defined at the center (halfway through the thickness). The metal crystalline phase fraction is preferably 10% or more, more preferably 20% or more, and most preferably 40% or more. This metal crystalline phase fraction may be 99% or less, or may be 70% or less.

[0031] Furthermore, in order to reduce the residual magnetization in the magnetic metal layer 3, the coercive force at 20°C is preferably 50 A / m or less, more preferably 20 A / m or less, even more preferably 10 A / m or less, and most preferably 5 A / m or less. This coercive force is measured with a BH tracer.

[0032] For example, to reduce the residual magnetization in the magnetic metal layer 3, it is desirable to sufficiently reduce the amount of compound phases (e.g., Fe2B and Fe3P). The amount of this compound phase is preferably reduced to a level that is not detectable in the spectrum obtained by XRD. For example, the method disclosed in International Publication No. 2017 / 022594 is used. That is, the compound crystalline phase ratio is defined as the ratio of the compound phase to all phases at the above-mentioned main position (i.e., the value of Y in this International Publication is defined as the compound crystalline phase ratio). The compound crystalline phase ratio is preferably 2% or less, and more preferably 1% or less. This compound crystalline phase ratio may be 0% or more. As the compound phase increases, the amount of amorphous phase in the magnetic metal layer 3 decreases.

[0033] The magnetic metal layer 3 may include a thin ribbon, or may include a material formed by molding powder into layers. If the magnetic metal layer 3 is continuous, leakage of magnetic flux is reduced, improving the shielding ability of the laminate 1. For this reason, it is preferable that the magnetic metal layer 3 includes a thin ribbon. It is also preferable that the thin ribbon has few cracks. In particular, it is preferable that there are no cracks that penetrate the magnetic metal layer 3.

[0034] The chemical composition of the metal contained in the magnetic metal layer 3 is not particularly limited, but for example, the following chemical compositions can be selected.

[0035] Fe, Ni, and Co are ferromagnetic and increase the saturation magnetic flux density. Therefore, the total amount of Fe, Ni, and Co is preferably 65.0 to 100 atomic %. When this metal contains an amorphous phase, from the viewpoint of the stability of the amorphous phase, the total amount of Fe, Ni, and Co is preferably 65.0 to 92.0 atomic %. Examples of such metals include an alloy containing at least one element selected from the group consisting of boron (B), Si, P, and carbon (C) and at least one element selected from the group consisting of Fe, Ni, and Co, and an alloy containing at least one element selected from the group consisting of Zr, hafnium (Hf), and niobium (Nb) and at least one element selected from the group consisting of Fe, Ni, and Co.

[0036] B, Si, P, C, Zr, Hf, and Nb enhance the thermal stability of the amorphous phase. Therefore, the total amount of B, Si, P, C, Zr, Hf, and Nb is preferably 8.0 atomic % or more. On the other hand, to obtain a high saturation magnetic flux density, this total amount is preferably 35.0 atomic % or less. When thermal stability is imparted to the amorphous phase mainly by B, Si, P, and C, which have smaller atomic radii than Fe, Ni, and Co, the total amount of B, Si, P, and C is preferably 10.0 atomic % or more, more preferably 12.0 atomic % or more, and most preferably 14.0 atomic % or more. On the other hand, to obtain a high saturation magnetic flux density, this total amount is preferably 35.0 atomic % or less, more preferably 20.0 atomic % or less, even more preferably 16.0 atomic % or less, and most preferably 15.0 atomic % or less. Since B, Si, P, and C significantly increase the activity of each other in the amorphous phase and thereby significantly enhance the stability of the amorphous phase, it is preferable that two or more elements be selected from the group consisting of B, Si, P, and C, more preferably three or more, and most preferably four. When thermal stability is imparted to the amorphous phase mainly by Zr, Hf, and Nb, which have larger atomic radii than Fe, Ni, and Co, the total amount of Zr, Hf, and Nb is preferably 5.0 atomic % or more, more preferably 8.0 atomic % or more. On the other hand, to obtain a high saturation magnetic flux density, this total amount is preferably 15.0 atomic % or less, more preferably 10.0 atomic % or less.

[0037] Among Fe, Ni, and Co, Fe is advantageous in terms of cost. Furthermore, elements with smaller atomic radii are more advantageous than elements with larger atomic radii in obtaining high saturation magnetic flux density while maintaining the stability of the amorphous phase. Therefore, as an example, the following describes a chemical composition in which Fe is the main component of the magnetic metal layer 3 and at least one element selected from the group consisting of B, Si, P, and C. In this example, the total amount of Fe, B, Si, P, C, optional elements (Cu, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Co, Ni, Cu, Ag, Zn, Al, Sn, As, Sb, Bi, and rare earth elements (REM)), and impurities is 100 atomic %.

[0038] Fe has ferromagnetism and increases the saturation magnetic flux density. Therefore, the amount of Fe is preferably 65.0 atomic % or more, more preferably 70.0 atomic % or more, more preferably 75.0 atomic % or more, more preferably 79.0 atomic % or more, even more preferably 81.0 atomic % or more, and most preferably 83.0 atomic % or more. On the other hand, to improve the stability of the amorphous phase, the amount of Fe is preferably 92.0 atomic % or less, more preferably 88.0 atomic % or less, more preferably 86.0 atomic % or less, and most preferably 85.0 atomic % or less.

[0039] B particularly enhances the thermal stability of the amorphous phase. Therefore, the amount of B is preferably 0.1 atomic % or more, more preferably 1.0 atomic % or more, more preferably 5.0 atomic % or more, even more preferably 7.5 atomic % or more, and most preferably 8.0 atomic % or more. On the other hand, to obtain a high saturation magnetic flux density, the amount of B is preferably 16.0 atomic % or less, more preferably 13.0 atomic % or less, even more preferably 11.0 atomic % or less, even more preferably 10.0 atomic % or less, and most preferably 9.4 atomic % or less. Depending on the amounts of Si, P, and C, the amount of B may be 0 atomic %.

[0040] Si enhances the thermal stability of the amorphous phase and increases the temperature at which the compound phase forms during heat treatment. Therefore, the amount of Si is preferably 0.1 atomic % or more, more preferably 0.2 atomic % or more, more preferably 0.5 atomic % or more, even more preferably 1.0 atomic % or more, and most preferably 2.0 atomic % or more. Si can also form a silica surface coating through oxidation, imparting insulation and corrosion resistance to the magnetic metal layer. In this case, the amount of Si is preferably 8.0 atomic % or more, and more preferably 10.0 atomic % or more. On the other hand, to obtain a high saturation magnetic flux density, the amount of Si is preferably 15.0 atomic % or less, more preferably 10.0 atomic % or less, more preferably 8.0 atomic % or less, even more preferably 5.0 atomic % or less, and most preferably 4.0 atomic % or less. Depending on the amounts of B, P, and C, the amount of Si may be 0 atomic %.

[0041] P enhances the thermal stability of the amorphous phase and maintains fine crystal grains during heat treatment. Therefore, the amount of P is preferably 0.1 atomic % or more, more preferably 1.0 atomic % or more, even more preferably 2.0 atomic % or more, and most preferably 3.0 atomic % or more. On the other hand, to obtain a high saturation magnetic flux density, the amount of P is preferably 15.0 atomic % or less, more preferably 10.0 atomic % or less, even more preferably 8.0 atomic % or less, and most preferably 5.0 atomic % or less. Depending on the amounts of B, Si, and C, the amount of P may be 0 atomic %.

[0042] C improves the thermal stability of the amorphous phase. Therefore, the amount of C is preferably 0.1 atomic % or more, more preferably 0.5 atomic % or more, and most preferably 1.0 atomic % or more. On the other hand, in order to obtain a high saturation magnetic flux density, the amount of C is preferably 10.0 atomic % or less, more preferably 8.0 atomic % or less, even more preferably 5.0 atomic % or less, and most preferably 3.0 atomic % or less. Depending on the amounts of B, Si, and P, the amount of C may be 0 atomic %.

[0043] Furthermore, in order to stably disperse crystal grains in the amorphous phase and stably increase the saturation magnetic flux density using a readily available heat treatment method, the magnetic metal layer 3 may contain, for example, Cu as an optional element. The amount of Cu is preferably 0.1 atomic % or more, more preferably 0.4 atomic % or more, even more preferably 0.5 atomic % or more, and most preferably 0.6 atomic % or more. From the viewpoint of maintaining the thermal stability of the amorphous phase and a high saturation magnetic flux density, the amount of Cu is preferably 2.0 atomic % or less, more preferably 1.5 atomic % or less, even more preferably 1.1 atomic % or less, even more preferably 1.0 atomic % or less, and most preferably 0.9 atomic % or less. The amount of Cu may even be 0 atomic %.

[0044] In addition to the above, to impart additional effects related to the above characteristics or other properties, the magnetic metal layer 3 may contain, for example, at least one element selected from the group consisting of titanium (Ti), Zr, Hf, vanadium (V), Nb, tantalum (Ta), Cr, molybdenum (Mo), tungsten (W), manganese (Mn), Co, Ni, Ag, Zn, Al, Sn, arsenic (As), antimony (Sb), bismuth (Bi), and rare earth metal (REM). Among these elements, Co is expensive, but significantly improves saturation magnetic flux density when combined with Fe. Therefore, the amount of Co is preferably 0.1 atomic % or more, more preferably 1.0 atomic % or more, and most preferably 3.0 atomic %. Considering the cost advantage of using Fe as the main component, the amount of Co may be half the amount of Fe or 30.0 atomic % or less. Ni can also improve corrosion resistance without significantly reducing saturation magnetic flux density. Therefore, the amount of Ni is preferably 0.1 atomic % or more, more preferably 1.0 atomic % or more, and most preferably 3.0 atomic %. Considering the cost advantage of using Fe as the main component, the amount of Ni may be 15.0 atomic % or less. The total amount of Fe, Ni, and Co is preferably 65.0 to 90.0 atomic %. Even when imparting additional effects related to the above properties or other properties, from the viewpoint of maintaining a high saturation magnetic flux density, the total amount of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Ag, Zn, Al, Sn, As, Sb, Bi, and REM is preferably 8.0 atomic % or less, more preferably 5.0 atomic % or less, even more preferably 3.0 atomic % or less, and most preferably 1.0 atomic % or less. The total amount of Fe, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Co, Ni, Ag, Zn, Al, Sn, As, Sb, Bi and REM is preferably 65.0 to 90.0 atomic %. These optional elements may be 0 atomic %.REM stands for scandium (Sc), yttrium (Y), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu).

[0045] In addition to the above, the magnetic metal layer 3 may unavoidably contain impurities. However, the amount of impurities is preferably 0.5 atomic % or less, more preferably 0.1 atomic % or less, even more preferably 0.05 atomic % or less, and most preferably 0.01 atomic % or less. For example, impurities include, but are not limited to, O, N, S, Pb, and Cd. The impurities may be 0 atomic %.

[0046] Therefore, in one embodiment of the present invention, in a magnetic metal layer containing an amorphous phase, the total amount of Fe, Ni, and Co is 65.0 to 90.0 atomic %, the amount of Cu is 0 to 2.0 atomic %, the total amount of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Ag, Zn, Al, Sn, As, Sb, Bi, and REM is 0 to 8.0 atomic %, and the remainder is at least one element selected from the group consisting of B, Si, P, and C, and impurities, and the total amount of Fe, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Co, Ni, Ag, Zn, Al, Sn, As, Sb, Bi, and REM is 65.0 to 90.0 atomic %.

[0047] In another embodiment of the present invention, in a magnetic metal layer containing an amorphous phase, the total amount of Fe, Ni, and Co is 65.0 to 92.0 atomic %, the amount of Cu is 0 to 2.0 atomic %, the total amount of Ti, V, Ta, Cr, Mo, W, Mn, Ag, Zn, Al, Sn, As, Sb, Bi, and REM is 0 to 8.0 atomic %, the total amount of B, Si, P, and C is 0 to 10.0 atomic %, and the balance is at least one selected from the group consisting of Zr, Hf, and Nb, and impurities.

[0048] In another embodiment of the present invention, in the magnetic metal layer containing an amorphous phase, the amount of Fe is 79.0 to 88.0 atomic %, the amount of B is 5.0 to 15.0 atomic %, the amount of Si is 0 to 8.0 atomic %, the amount of P is 1.0 to 8.0 atomic %, the amount of C is 0 to 5.0 atomic %, the amount of Cu is 0 to 1.4 atomic %, and the amount of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Ag, Zn, Al, Sn, As, Sb, Bi and REM is 0 to 8.0 atomic %, the total amount of Fe, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Co, Ni, Ag, Zn, Al, Sn, As, Sb, Bi and REM is 79.0 to 88.0 atomic %, and the total amount of Fe, B, Si, P, C, Cu, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Co, Ni, Ag, Zn, Al, Sn, As, Sb, Bi and REM is 100%.

[0049] In this example, the alloy composition disclosed in WO 2010 / 021130 can be suitably used as the magnetic metal layer 3 containing an amorphous phase. Therefore, the disclosure of WO 2010 / 021130 is incorporated herein by reference in its entirety to the extent that it does not contradict the contents of this specification.

[0050] For example, when stably dispersing crystal grains in an amorphous phase and prioritizing the synergistic effect of P and Cu (crystal grain refinement), the ratio of the amount of Cu (atomic %) to the amount of P (atomic %) is preferably 0.08 to 0.80, and more preferably 0.08 to 0.55.

[0051] Also, for example, excluding impurities, the composition formula is Fe a B b Si c P x C y Cu zIn this case, it is preferable that the amount of Fe (a) is 79.0 to 88.0 atomic %, the amount of B (b) is 5.0 to 15.0 atomic %, the amount of Si (c) is 0 to 8.0 atomic %, the amount of P (x) is 1.0 to 8.0 atomic %, the amount of C (y) is 0 to 5.0 atomic %, and the amount of Cu (z) is 0 to 1.4 atomic %.

[0052] When the magnetic metal layer 3 is sufficiently thick, the strength of the magnetic metal layer 3 is sufficiently high, thereby improving the processability of the laminate 1. Therefore, the thickness of the magnetic metal layer 3 is preferably 4 μm or more. Furthermore, when the magnetic metal layer 3 is thick, the electromagnetic wave shielding effect of the magnetic metal layer 3 increases. Therefore, the thickness of the magnetic metal layer 3 is more preferably 10 μm or more, more preferably 15 μm or more, and even more preferably 20 μm or more. When the magnetic metal layer 3 is sufficiently thin, the strength of the magnetic metal layer 3 is sufficiently small, thereby sufficiently improving the formability of the laminate 1. Therefore, the thickness of the magnetic metal layer 3 is preferably 100 μm or less, more preferably 50 μm or less, even more preferably 45 μm or less, and most preferably 40 μm or less. When the laminate 1 includes multiple magnetic metal layers 3, one magnetic metal layer 3 may be within the above-mentioned thickness range, some of the magnetic metal layers 3 may be within the above-mentioned thickness range, or all of the magnetic metal layers 3 may be within the above-mentioned thickness range.

[0053] Furthermore, the laminate 1 may optionally include a magnetic metal layer 3 that does not contain an amorphous phase. For example, this magnetic metal layer 3 may include at least one selected from the group consisting of Fe, Ni, and Co in order to improve environmental resistance such as heat resistance and corrosion resistance, to improve adhesion between layers, or to improve the laminate's shielding ability against DC magnetic fields. In particular, when improving environmental resistance such as heat resistance and corrosion resistance, it is preferable that the magnetic metal layer 3 be present on the outermost surface of the laminate. Examples of such a magnetic metal layer 3 include Ni and Fe-Ni. These Ni and Fe-Ni can be formed not only by laminating foils but also by plating or vapor deposition.

[0054] In addition to the nonmagnetic metal layer 2 and the magnetic metal layer 3, the laminate 1 may optionally include a nonmetallic layer 4. For example, the nonmetallic layer 4 may contain a chromium compound to improve environmental resistance, such as heat resistance and corrosion resistance, or to improve interlayer adhesion. Furthermore, the nonmetallic layer 4 may contain a polymer to improve interlayer adhesion. For example, the polymer may be at least one selected from acrylic resin, epoxy resin, urethane resin, polyester, silicone resin, polyvinyl acetate, styrene-butadiene rubber, nitrile rubber, phenolic resin, and cyanoacrylate. From a cost perspective, the polymer is preferably a urethane resin, polyester resin, or polyvinyl acetate. Furthermore, the nonmetallic layer 4 may include an insulating layer to provide insulation between layers or on the surface. In particular, when improving environmental resistance, such as heat resistance and corrosion resistance, it is preferable that the nonmetallic layer 4 be present on the outermost surface of the laminate 1. To improve the electromagnetic wave shielding effect of the laminate 1 per unit thickness, the thickness of the non-metallic layer 4 is preferably 20 μm or less, more preferably 15 μm or less, even more preferably 10 μm or less, and most preferably 5 μm or less. Alternatively, the thickness of the non-metallic layer 4 may be 0.1 μm, 1.0 μm, 1.5 μm, or 2.0 μm or more.

[0055] (2. Manufacturing Method of Laminate) A method for manufacturing a laminate according to another embodiment of the present invention includes a lamination step of laminating materials containing a nonmagnetic metal and a magnetic metal containing an amorphous phase (amorphous magnetic metal) to form an unsintered laminate, as shown in the flowchart of Figure 3. This lamination step forms the nonmagnetic metal layer and the magnetic metal layer. The materials used for these layers and the structure of the layers are as described above, and therefore will not be described here.

[0056] If shaping is required depending on the application, a shaping step may be included in which the green laminate is shaped into a predetermined shape. This shaping step may include, for example, cutting, punching, deep drawing, stretching, bending, etc.

[0057] To increase the crystallinity of the amorphous magnetic metal to enhance the electromagnetic wave shielding effect of the laminate or to reduce distortion caused by the molding process, the present manufacturing method preferably includes a sintering step. In this sintering step, a sintered laminate is formed from an unsintered laminate or a pre-sintered laminate (described below). However, since the amorphous magnetic metal becomes more brittle as the crystallinity increases, it is preferable to include a sintering step after the molding process. The crystallinity of the amorphous magnetic metal obtained by the sintering step is preferably 10% or more, more preferably 20% or more, more preferably 30% or more, more preferably 40% or more, even more preferably 50% or more, even more preferably 60% or more, even more preferably 70% or more, even more preferably 80% or more, and most preferably 90% or more. This crystallinity may be 100% or less, or may be less than 100%. The heat treatment conditions are preferably varied depending on the material. For example, the heat treatment temperature may be 350 to 650° C., and is preferably higher than the temperature at which a metal crystalline phase precipitates and lower than the temperature at which a compound crystalline phase does not precipitate. The heat treatment time may be, for example, 1 to 3600 seconds.

[0058] Furthermore, in order to stably perform crystallization after the processing step or to adjust the formability in the molding step, a pre-firing step may be included between the lamination step and the molding step. In this pre-firing step, a pre-fired laminate is formed from the unfired laminate. In order to maintain the formability in the molding step, the crystallinity of the amorphous magnetic metal obtained by the pre-firing step is preferably 75% or less, more preferably 60% or less, more preferably 50% or less, more preferably 40% or less, more preferably 30% or less, even more preferably 20% or less, and most preferably 10% or less. This crystallinity may be 0% or more or 5% or more. In addition, in order to ensure the stability of crystallization in the firing step, the crystallinity of the amorphous magnetic metal obtained by the pre-firing step is preferably 10% or more, more preferably 20% or more, and most preferably 50% or more.

[0059] The manufacturing method of the nonmagnetic metal and amorphous magnetic metal is not limited. For example, when the nonmagnetic metal is copper foil, the copper foil may be any of rolled copper foil, electrolytic copper foil, and metallized copper foil. Furthermore, the magnetic metal containing an amorphous phase may be manufactured by either a gas phase or liquid phase quenching method. For example, in the case of a thin ribbon, such manufacturing methods include the single-roll method, the twin-roll method, the thermal spraying method, the plating method, and the vapor deposition method. In the case of a powder, examples include a method of pulverizing a thin ribbon, as well as a water atomization method and a gas atomization method. Materials in which additional processing has been performed on the nonmagnetic metal and amorphous magnetic metal may also be used. For example, a material in which the amorphous magnetic metal has been heat-treated in advance may be used to adjust the amount of strain previously contained in the amorphous magnetic metal and reduce warping due to dimensional changes in the material after heat treatment. Even in this case, the crystallinity is not limited. However, if sufficient formability is required, a crystallinity of 0 to 5% is preferable. Furthermore, for example, for the purpose of imparting additional electromagnetic wave shielding effect, environmental resistance, or adhesion to the laminate, materials that have been subjected to various plating treatments (Au, Ag, Sn, Ni, Fe-Ni alloy, Zn, Sn alloy [Sn-Ag, Sn-Ni, Sn-Cu]), various chemical conversion treatments (chromate treatment), or roughening treatments may be used as the nonmagnetic metal and amorphous magnetic metal. From the viewpoint of both environmental resistance and cost, it is preferable that the material contains Sn plating or Sn alloy plating. From the viewpoint of adhesion, it is preferable to use a material that has been roughened. These additional treatments may be applied to the material in multiple ways.

[0060] In the lamination process, when the layers are bonded together without the use of an adhesive, for example, a surface activated bonding method may be used. In this surface activated bonding method, the surfaces of the nonmagnetic metal and the amorphous magnetic metal are activated, and the activated surfaces of both metals are brought into contact and bonded. The contact can be achieved by pressure bonding using overlapping rolls. Examples of methods for activating the surfaces of both metals include ion etching and dry film formation in a vacuum. The surface activation methods for each metal may be the same or different. Furthermore, when an adhesive is used, for example, an adhesive compatible with the aforementioned polymer (e.g., polyol and isocyanate in the case of urethane resin) can be used. In this case, it is preferable to compare the heat resistance conditions of the adhesive with the heat treatment conditions of the amorphous magnetic metal and adjust the heat treatment of the amorphous magnetic metal so as not to deteriorate the adhesive.

[0061] Furthermore, in order to impart aesthetic appearance, environmental resistance, and other properties to the laminate, the surface of the laminate may be subjected to a surface treatment in the final step. If lamination with an adhesive is required, for example, an additional lamination step may be added as part of this surface treatment. Heat treatment may be performed after this additional lamination step. In this case, when an adhesive or polymer is used, it is preferable that the heat treatment temperature be lower than the heat resistance temperature of the adhesive or polymer.

[0062] The laminate as a product may be an unfired laminate, a prefired laminate, or a fired laminate, regardless of whether it has been molded or not. Even if it is an unfired laminate or a prefired laminate, it can be used as is if it has a sufficient shielding effect against electromagnetic waves. The degree of crystallization of the amorphous magnetic metal can be adjusted depending on the purpose.

[0063] The laminate and the method for manufacturing the laminate according to the above-described embodiments can be used in various electromagnetic shielding applications, such as coating or exterior materials for electric and electronic devices (e.g., inverters, communication devices, resonators, electron tubes and discharge lamps, electric heating devices, electric motors, generators, electronic components, printed circuits, medical devices, etc.), coating materials for harnesses and communication cables connected to electric and electronic devices, electromagnetic shielding sheets, electromagnetic shielding panels, electromagnetic shielding bags, electromagnetic shielding boxes, and electromagnetic shielding rooms. [Example]

[0064] Examples of the present invention will be described below together with comparative examples, which are provided for a better understanding of the present invention and its advantages, but are not intended to limit the invention.

[0065] Rolled copper foil was used as the non-magnetic metal. This rolled copper foil was made of pure copper [non-magnetic (diamagnetic)] with a thickness of 12 μm, and had a conductivity of 58.0 × 10 at 20 °C. 6 The amorphous magnetic metal used was an amorphous metal ribbon manufactured by the single-roll method. This amorphous metal ribbon had a metal crystalline phase ratio of 0% (measured on both sides of the ribbon using a Rigaku MiniFlex 600 under the conditions of a Cu target, a tube voltage of 40 kV, a tube current of 15 mA, a step size of 0.01°, and a scan speed of 10° / min [θ-2θ method]), a crystallinity of 0% (defined), a thickness of 25 μm, a saturation magnetic flux density of 1.57 T (the saturation mass magnetization of an 8 × 8 mm sample was measured using a Toei Kogyo VSM-P7-15, and the saturation magnetic flux density was calculated by multiplying this saturation mass magnetization by 4π and the density calculated by the Archimedes method), and a coercive force of 16.5 A / m (measured on a 10 × 70 mm sample using a Riken Denshi Model BHS-40). The chemical composition was Fe 84.8 B 9.4 Si 0.5 P 3.5 Cu 0.8 C 1.0(atomic %) [magnetic (ferromagnetic)], and the amount of impurities (total amount of elements excluding the six elements mentioned above) was 0.1 atomic % or less. The copper foil and the amorphous metal ribbon were cut so that their lengths and widths were approximately the same.

[0066] In Examples 1 to 5, the surfaces of the rolled copper foil and the amorphous metal ribbon were activated by ion etching (plasma) and then rolled together to form a bond (surface activated bonding). This bonding process resulted in a green laminate, with the copper foil forming the nonmagnetic metal layer and the amorphous metal ribbon forming the magnetic metal layer having an amorphous phase. A portion of the green laminate in each of these Examples was passed through a 0.75 m long furnace set at 455°C at a speed of 1.5 m / min to crystallize a portion of the magnetic metal layer and form a pre-fired laminate (pre-firing step) [crystallinity: 53%] (measured on a 20 mg sample at a heating rate of 40°C / min using a PerkinElmer DSC8500). In addition, a portion of the unsintered laminate and pre-sintered laminate of the example was heated to 425°C at a heating rate of 1°C / min in a furnace while being kept flat, and then held for 10 minutes, followed by furnace cooling, to sufficiently crystallize the magnetic metal layer and form a sintered laminate (sintering process) [crystallinity of 99% or more]. The maximum differential relative permeability (measured using Model BHS-40 manufactured by Riken Denshi Co., Ltd.) was 1.5 x 10 for Examples 1, 4, and 5, respectively. 4 , 1.2 × 10 3 and 6.9 x 10 3 Similarly, the values ​​obtained by dividing the maximum value of the first differential relative magnetic permeability (longitudinal direction) by the maximum value of the second differential relative magnetic permeability (width direction) were 0.94, 0.97, and 1.01 for Examples 1, 4, and 5, respectively. In addition, the values ​​obtained by dividing the difference between the maximum value of the first differential relative magnetic permeability and the maximum value of the second differential relative magnetic permeability by the maximum value of the differential relative magnetic permeability were 6.3 × 10 for Examples 1, 4, and 5, respectively. -2 , 2.6×10 -2 and 9.9 x 10 -3 It was.

[0067] In Example 6, an amorphous metal ribbon was passed through a furnace with a length of 0.75 m and set at 490°C at a speed of 1.0 m / min, whereby the amorphous metal ribbon was partially crystallized (crystallinity: 60%, saturation magnetic flux density: 1.75 T). This crystallized amorphous metal ribbon was bonded to copper foil (thickness: 12 μm) with an adhesive to form a laminate. This bonding resulted in the nonmagnetic layer (resin film [derived from the adhesive]) being in contact with the nonmagnetic metal layer (copper foil), and the magnetic metal layer (amorphous metal ribbon) having an amorphous phase being in contact with this nonmagnetic layer. Because a urethane-based adhesive was used as the adhesive, the nonmagnetic layer was a urethane resin layer. In Examples 1 to 6, the layers were laminated so that their end faces coincided.

[0068] In Comparative Example 1, copper foil (thickness 12 μm) was used as is (corresponding to only the non-magnetic metal layer), and in Comparative Example 2, amorphous metal ribbon (thickness 25 μm) was used as is (corresponding to only the magnetic metal layer).

[0069] Table 1 lists the layer structure of the actual laminate, as well as the firing structure, the crystallinity of the magnetic metal layer, and the average crystal grain size.

[0070] (Evaluation of electromagnetic wave shielding effectiveness) The laminates of each example and comparative example were placed in an electromagnetic wave shielding effectiveness evaluation device (Techno Science Japan, model TSES-KEC), and the electromagnetic wave shielding effectiveness was evaluated by the KEC method under conditions of frequencies of 500 kHz and 1 MHz and a temperature of 20° C. The evaluation criteria were as follows: [Shielding effectiveness evaluation at a frequency of 500 kHz] A: Magnetic field shielding effect is 35.0 dB or more B: Magnetic field shielding effect is 25.0 dB or more and less than 35.0 dB C: Magnetic field shielding effect is less than 25.0 dB [Shielding effectiveness evaluation at a frequency of 1 MHz] A: Magnetic field shielding effect is 40.0 dB or more B: Magnetic field shielding effect is 30.0 dB or more and less than 40.0 dB C: Magnetic field shielding effect is less than 30.0 dB [Overall evaluation of magnetic field shielding effectiveness] A: Both 500kHz and 1MHz are rated A B: Evaluated at either 500 kHz or 1 MHz with a B rating C: C rating at either 500 kHz or 1 MHz

[0071] (Moldability) A 125 mm × 125 mm test piece was cut from each laminate of each example and comparative example, wrapped around a Φ18 mm round rod with the copper foil facing outward, and then unfolded to determine whether cracks had occurred on the front and back surfaces of the test piece. If cracks penetrating the nonmagnetic metal layer or the magnetic metal layer were observed, the test piece was rated "B" (poor). If no cracks penetrating either the nonmagnetic metal layer or the magnetic metal layer were observed, the test piece was rated "A" (good) (see Figures 4A and 4B). A test piece was also rated "A" (good) when no molding process was applied. [Table 1]

[0072] (Table 1) According to Table 1, a laminate including a nonmagnetic metal layer and a magnetic metal layer containing an amorphous phase had a higher electromagnetic wave shielding effect than a laminate including only a nonmagnetic metal layer or only a magnetic metal layer. Furthermore, by appropriately adjusting the crystallinity of the magnetic metal layer containing an amorphous phase, it was possible to enhance the electromagnetic wave shielding effect in the low frequency range while maintaining sufficient formability. Furthermore, the provision of a nonmagnetic metal layer also provided a high electromagnetic wave shielding effect in the mid- to high-frequency range.

Claims

1. A laminate comprising at least one non-magnetic metal layer and at least one magnetic metal layer, at least one of the magnetic metal layers including an amorphous phase.

2. 2. The laminate according to claim 1, wherein the magnetic metal layer containing the amorphous phase has a crystallinity of 10% or more.

3. The laminate according to claim 1 or 2, wherein at least a portion of the laminate is molded.

4. 4. The laminate according to claim 1, wherein the non-magnetic metal layer has a thickness of 4 to 100 μm.

5. 5. The laminate according to claim 1, wherein the magnetic metal layer has a thickness of 4 to 100 μm.

6. 6. The laminate according to claim 1, wherein the total thickness of the non-magnetic metal layer and the magnetic metal layer is 15 to 150 μm.

7. 7. The laminate according to claim 1, wherein the non-magnetic metal layer is selected from the group consisting of aluminum foil, aluminum alloy foil, copper foil, and copper alloy foil.

8. 8. The laminate according to any one of claims 1 to 7, wherein in the magnetic metal layer containing the amorphous phase, the total amount of Fe, Ni, and Co is 65.0 to 90.0 atomic %, the amount of Cu is 0 to 2.0 atomic %, the total amount of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Ag, Zn, Al, Sn, As, Sb, Bi, and REM is 0 to 8.0 atomic %, and the balance is at least one element selected from the group consisting of B, Si, P, and C, and impurities, and the total amount of Fe, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Co, Ni, Ag, Zn, Al, Sn, As, Sb, Bi, and REM is 65.0 to 90.0 atomic %.

9. 8. The laminate according to any one of claims 1 to 7, wherein the magnetic metal layer containing the amorphous phase has a total content of Fe, Ni, and Co of 65.0 to 92.0 atomic %, a content of Cu of 0 to 2.0 atomic %, a total content of Ti, V, Ta, Cr, Mo, W, Mn, Ag, Zn, Al, Sn, As, Sb, Bi, and REM of 0 to 8.0 atomic %, a total content of B, Si, P, and C of 0 to 10.0 atomic %, and the balance being at least one element selected from the group consisting of Zr, Hf, and Nb, and impurities.

10. In the magnetic metal layer containing the amorphous phase, the amount of Fe is 79.0 to 88.0 atomic %, the amount of B is 5.0 to 15.0 atomic %, the amount of Si is 0 to 8.0 atomic %, the amount of P is 1.0 to 8.0 atomic %, the amount of C is 0 to 5.0 atomic %, the amount of Cu is 0 to 1.4 atomic %, and the total amount of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Ag, Zn, Al, Sn, As, Sb, Bi and REM is 0 to 8.0 atomic %.

8. The laminate according to claim 1, wherein the total amount of Fe, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Co, Ni, Ag, Zn, Al, Sn, As, Sb, Bi, and REM is 79.0 to 88.0 atomic %, and the total amount of Fe, B, Si, P, C, Cu, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Co, Ni, Ag, Zn, Al, Sn, As, Sb, Bi, and REM is 100%.

11. The conductivity of the non-magnetic metal layer is 30.0×10 6 11. The laminate according to claim 1, wherein the saturation magnetic flux density of the magnetic metal layer containing the amorphous phase is 1.50 T or more.

12. 12. The laminate according to claim 1, wherein at least one of the non-magnetic metal layers and at least one of the magnetic metal layers containing an amorphous phase are in contact with each other.

13. A method for manufacturing a laminate, comprising a lamination step of laminating materials containing a non-magnetic metal and an amorphous magnetic metal to form a green laminate.

14. The method for producing a laminate according to claim 13, further comprising a firing step of firing the green laminate so that the layer of the amorphous magnetic metal in the green laminate has a crystallinity of 10% or more.

15. The method for producing a laminate according to claim 14, further comprising a forming step of processing the green laminate into a predetermined shape before the firing step.

16. The method for manufacturing a laminate according to claim 15, further comprising a pre-firing step of pre-firing the green laminate before the molding step so that the crystallinity of the amorphous magnetic metal in the green laminate is 10 to 75%.

17. 17. The method for manufacturing a laminate according to claim 13, wherein in the laminating step, the non-magnetic metal and the amorphous magnetic metal are bonded by a surface activated bonding method.

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