EP0337716A2 - Magnetic ribbon and magnetic core - Google Patents

Magnetic ribbon and magnetic core Download PDF

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Publication number
EP0337716A2
EP0337716A2 EP89303542A EP89303542A EP0337716A2 EP 0337716 A2 EP0337716 A2 EP 0337716A2 EP 89303542 A EP89303542 A EP 89303542A EP 89303542 A EP89303542 A EP 89303542A EP 0337716 A2 EP0337716 A2 EP 0337716A2
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EP
European Patent Office
Prior art keywords
magnetic
ribbon
particles
magnetic ribbon
attached
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EP89303542A
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German (de)
French (fr)
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EP0337716A3 (en
EP0337716B1 (en
Inventor
Takashi Matsuoka
Toshikazu Furihata
Yasushi Ueda
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Nippon Chemi Con Corp
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Mitsui Petrochemical Industries Ltd
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    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01FMAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F1/00Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01FMAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F41/00Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
    • H01F41/02Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
    • H01F41/0206Manufacturing of magnetic cores by mechanical means
    • H01F41/0213Manufacturing of magnetic circuits made from strip(s) or ribbon(s)
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01FMAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F1/00Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
    • H01F1/01Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
    • H01F1/03Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
    • H01F1/12Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials
    • H01F1/14Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys
    • H01F1/147Alloys characterised by their composition
    • H01F1/153Amorphous metallic alloys, e.g. glassy metals
    • H01F1/15383Applying coatings thereon
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01FMAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F1/00Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
    • H01F1/01Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
    • H01F1/03Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
    • H01F1/12Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials
    • H01F1/14Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys
    • H01F1/16Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys in the form of sheets
    • H01F1/18Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys in the form of sheets with insulating coating
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01FMAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F27/00Details of transformers or inductances, in general
    • H01F27/24Magnetic cores
    • H01F27/25Magnetic cores made from strips or ribbons

Definitions

  • the present invention relates to a magnetic ribbon and a magnetic core formed by using said magnetic ribbon.
  • a magnetic core is formed by winding or laminating a magnetic ribbon, and if insulation between layers of the ribbon is poor, an eddy current flowing across the ribbon layers occurs and an increase in eddy current losses results in an increase in overall core losses (magnetic losses). This tendency is particularly noticeable in the case of high frequencies. In addition, the frequency characteristics of permeability is poor, and it is impossible to expect any advantageous use at 100 kHz or more.
  • an insulating layer formed of a nonmagnetic material is conventionally provided between the ribbon layers, and a uniform insulating film is formed on the ribbon surface as one means thereof, so as to solve the aforementioned problem.
  • annealing is usually carried out at 400°C or thereabouts. However, if such annealing is carried out, because of a difference in the coefficient of linear expansion, i.e., since the coefficient of linear expansion of the insulating film is greater than that of the amorphous ribbon, compressive stress occurs in the ribbon, and magnetic characteristics deteriorate due to the adverse effect of magnetostriction.
  • an insulating film is generally interposed between ribbon layers, and the greatest matter of concern to those skilled in the art lies in finding an insulating material having an excellent insulating performance.
  • a magnetic ribbon on at least one side of which particles, preferably fine particles, formed of a nonmagnetic, preferably inorganic, substance having insulating properties are attached.
  • the invention also provides a magnetic core having such a ribbon wound therearound or laminated thereon.
  • the particles may be attached so as to secure a layer of air so that in the absence of a conventional insulating film, the air present between the layers can serve as an insulating layer and prevent an eddy current, and the space factor can be made as large as possible.
  • particles formed of an inorganic substance are attached on at least one surface of the magnetic ribbon, so that if the magnetic ribbon is wound or laminated to form a magnetic core, the particles serve as a spacer, thereby forming a layer of air between adjacent layers of the ribbon.
  • the particles may be attached uniformly and densely on at least one surface of the ribbon.
  • the particles themselves function as an insulating layer. Nevertheless, in this case as well, it is possible to obtain the same effect as that obtained by securing a layer of air by means of the particles. Accordingly, the present invention includes both the case where the particles are attached coarsely and the case where they are attached densely.
  • the particles may be applied by any suitable method for example by passing the magnetic ribbon through a suspension containing the particles. Where it is intended that the particles should act as a spacer trapping a layer of air between layers or windings of a core the proportion of particles in the suspension may be chosen to be suitably low. For example where the particles are antimony pentoxide suspended in toluene they may form 1% to 10%, preferably 2% to 5%, eg about 3%, by weight of the suspension.
  • the particles should be attached more densely so as to act as the insulation then a higher proportion may be used in the suspension.
  • a higher proportion may be used in the suspension.
  • 20% by weight for example 20% to 50%, e.g. about 30% by weight.
  • a magnetic ribbon and a magnetic core can be provided having excellent magnetic characteristics while securing insulating properties between ribbon layers with the space factor reduced.
  • the magnetic ribbon referred to in the present invention is a thin magnetic strip, and, as magnetic materials, it is possible to cite the following: ferromagnetic elements such as Fe, Co, and Ni among transition metals, alloys of ferromagnetic elements, alloys of ferromagnetic elements and nonferromagnetic elements which are added to improve characteristics, ferrite, permalloy, amorphous alloys, etc.
  • ferromagnetic elements such as Fe, Co, and Ni among transition metals
  • alloys of ferromagnetic elements alloys of ferromagnetic elements and nonferromagnetic elements which are added to improve characteristics, ferrite, permalloy, amorphous alloys, etc.
  • Fe-based alloys such as Fe-B, Fe-B-C, Fe-B-Si, Fe-B-Si-C, Fe-B-Si-Cr, Fe-Co-B-Si, and Fe-Ni-Mo-B
  • Co-based alloys such as Co-B, Co-Fe-Si-B, Co-Fe-Ni-Mo-B-Si, Co-Fe-Ni-B-Si, Co-Fe-Mn-B-Si, Co-Fe-Mn-Ni, Co-Mn-Ni-B-Si, and Co-Fe-Mn-Ni-B, and other similar alloys.
  • inorganic fine particles that are attached to such a magnetic ribbon are that it is nonmagnetic, and that it has insulating properties. If the fine particles are magnetic and conductive, an adverse effect is exerted on magnetic characteristics, and an eddy current is liable to flow.
  • inorganic substances used in the present invention it is possible to cite the following: (1) inorganic substances which are stable in a natural condition, including glass (sodium silicate), mica (aluminosilicate alkali salt and phyllosilicate alkali salt), silicon carbide, calcium sulfate semi-water salt, potassium carbonate, magnesium carbonate, calcium carbonate, barium sulfate, and the like; (2) metal oxides such as aluminum oxide, boron oxide, magnesium oxide, silicon dioxide, tin dioxide, zinc oxide, zirconium dioxide, antimony pentoxide, and the like; and (3) ceramics formed of the materials cited in (2) above and double oxides such as perovskite, silicate glass, phosphate, titanic acid salt, niobium, tantalum, and tungstate; ceramics formed singly or in a combination by using such ceramic materials as nitrides, including aluminum nitride, a sintered body of aluminum oxide and nitride, boron nitrid
  • the size of the fine particles of the inorganic substance if consideration is paid to the fact that the fine particles are attached to the ribbon uniformly so as to form an insulating layer, the size of the fine particles may be small. However, if the particle size is made too small, it constitutes a factor making manufacture difficult. Meanwhile, if the particle size is too large, when the magnetic core is formed by a ribbon, the gap between the adjacent layers of the ribbon becomes too large, so that the space factor of the magnetic material becomes small. For this reason, it is preferred that the size of the fine particles is set in the range of 10 nm to 2 ⁇ m.
  • the fine particles may preferably be attached in such a manner that they are attached by 10 ⁇ 7cm3 to 2 x 10 ⁇ ­4cm3, more preferably 3 x 10 ⁇ 6cm3 - 10 ⁇ 5cm3, per unit area (1 cm2). If this amount attached is calculated into the weight of fine particles per unit area, although its value changes depending on the specific weight of the material of the fine particles, in the case of antimony pentoxide, the weight is 3.8 x 10 ⁇ 7g/cm2 - 7.6 x 10 ⁇ 4g/cm2, preferably 1.1 x 10 ⁇ 5g/cm2 - 3.8 x 10 ⁇ 5g/cm2.
  • Means for attaching the fine particles is so arranged that these fine particles are dispersed in water or a volatile organic solvent such as toluene, and, after this solution is applied to the ribbon surface, force or natural drying is carried out, thereby allowing the fine particles to be attached to the ribbon.
  • the concentration of this solution determines the amount of fine particles to be attached to the ribbon.
  • this inorganic substance may be dispersed in toluene in a colloidal state at a rate of from 0.1 to 30 wt% with respect to toluene. 3 wt% or thereabouts in this range is also effective, a decline in the space factor is practically nil, and the magnetic characteristics do not deteriorate.
  • the thickness of the film of the solution applied is preferably 10 ⁇ m or less in determining the aforementioned amount of fine particles to be attached.
  • a drying furnace may be used for evaporation of the solvent depending on the solvent, and drying may be carried out at 100°C or above.
  • annealing may be carried out for 0.­5 - 5 hours at the temperature of 300 - 500°C in an inert gas atmosphere such as nitrogen so as to eliminate strain, as required.
  • This annealing may be effected after the ribbon is wound or laminated into a magnetic core, or may be effected in the state of the ribbon.
  • annealing may be effected at a temperature 10 to 50°C higher than the Curie point, a magnetic core exhibiting excellent characteristics with respect to high frequencies can be obtained.
  • annealing may be effected in a magnetic field or in a nonmagnetic field.
  • the magnetic core when the amorphous magnetic core with the ribbon wound therearound or laminated thereon is annealed since the fine particles disposed between adjacent ribbon layers are powders, the magnetic core is not subjected to linear expansion. The fine particles rather exhibit the action of absorbing the stress accompanying the shrinkage of the amorphous ribbon.
  • a magnetic ribbon and a solution containing fine particles are prepared.
  • the solution containing the fine particles is applied to at lest one surface of the magnetic ribbon by any of the various methods of application, and the solvent is allowed to dry.
  • the resultant magnetic ribbon with the fine particles attached thereto is wound under tension, thereby obtaining a toroidal-type magnetic core.
  • annealing for eliminating strain is carried out, as necessary.
  • tension applied at the time of winding is preferably 0.05 o 2 kg.
  • the ribbon with fine particles attached thereto is cut into a predetermined configuration, and the cut pieces are laminated so as to form the magnetic core.
  • Annealing which is carried out as necessary may be effected prior to the lamination or after the magnetic core has been formed subsequent to the lamination.
  • an amorphous ribbon 1a (2605S-2, Fe78-B13-Si9, 10 mm width) made by Allied Corp. is fed forward into a colloidal solution 2 of antimony pentoxide.
  • a colloidal solution 2 of antimony pentoxide As the colloidal solution 2 of antimony pentoxide, toluene was used as the solvent, and 3 wt% of antimony was dispersed with respect to toluene 97 wt%.
  • the ribbon 1b with the particles attached thereto was fed forward via a roller 5, and was wound under tension in a final stage, thereby forming an amorphous magnetic core 6.
  • a plurality of magnetic cores having the same dimensions were then formed, and were subjected to annealing for two hours at 435°C in a nitrogen atmosphere.
  • Organic solvent toluene, 100 wt%
  • Fine particles antimony pentoxide, 3 wt%
  • Organic solvent toluene, 70 wt%
  • Fine particles antimony pentoxide, 30 wt%
  • the magnetic cores of the Examples display a hysteresis which is closer to a linear configuration, and that the core loss is low as a whole, and a rise in the high-­frequency component can be reduced to a low level.
  • a substantially fixed permeability was obtained up to 200 kHz.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Dispersion Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Manufacturing & Machinery (AREA)
  • Soft Magnetic Materials (AREA)
  • Manufacturing Cores, Coils, And Magnets (AREA)
  • Magnetic Heads (AREA)
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  • Decoration Of Textiles (AREA)

Abstract

Disclosed are a magnetic ribbon on at least one surface of which fine particles formed of nonmagnetic inorganic substance having insulating properties are attached and a magnetic core around which this magnetic ribbon is wound or on which it is laminated. The fine particles serve as a spacer to form a layer of air between adjacent layers of the magnetic ribbon.

Description

  • The present invention relates to a magnetic ribbon and a magnetic core formed by using said magnetic ribbon.
  • If a magnetic core is formed by winding or laminating a magnetic ribbon, and if insulation between layers of the ribbon is poor, an eddy current flowing across the ribbon layers occurs and an increase in eddy current losses results in an increase in overall core losses (magnetic losses). This tendency is particularly noticeable in the case of high frequencies. In addition, the frequency characteristics of permeability is poor, and it is impossible to expect any advantageous use at 100 kHz or more.
  • Accordingly, in order to improve insulation between ribbon layers, an insulating layer formed of a nonmagnetic material is conventionally provided between the ribbon layers, and a uniform insulating film is formed on the ribbon surface as one means thereof, so as to solve the aforementioned problem.
  • In cases where an amorphous magnetic ribbon is processed as a magnetic ribbon, annealing is usually carried out at 400°C or thereabouts. However, if such annealing is carried out, because of a difference in the coefficient of linear expansion, i.e., since the coefficient of linear expansion of the insulating film is greater than that of the amorphous ribbon, compressive stress occurs in the ribbon, and magnetic characteristics deteriorate due to the adverse effect of magnetostriction.
  • In addition, there is another problem in that materials of such insulating films capable of withstanding annealing at 400°C or thereabouts are limited. Furthermore, if a magnetic core is formed by providing an insulating film, the filling factor (space factor) declines, which disadvantageously causes the magnetic core to become large in size.
  • Thus, as described above, when producing a magnetic core by using a magnetic ribbon, an insulating film is generally interposed between ribbon layers, and the greatest matter of concern to those skilled in the art lies in finding an insulating material having an excellent insulating performance.
  • In accordance with the present invention, there is provided a magnetic ribbon on at least one side of which particles, preferably fine particles, formed of a nonmagnetic, preferably inorganic, substance having insulating properties are attached.
  • The invention also provides a magnetic core having such a ribbon wound therearound or laminated thereon.
  • The particles may be attached so as to secure a layer of air so that in the absence of a conventional insulating film, the air present between the layers can serve as an insulating layer and prevent an eddy current, and the space factor can be made as large as possible.
  • That is, particles formed of an inorganic substance are attached on at least one surface of the magnetic ribbon, so that if the magnetic ribbon is wound or laminated to form a magnetic core, the particles serve as a spacer, thereby forming a layer of air between adjacent layers of the ribbon.
  • However, the particles may be attached uniformly and densely on at least one surface of the ribbon. In this case, rather than particularly securing a layer of air, the particles themselves function as an insulating layer. Nevertheless, in this case as well, it is possible to obtain the same effect as that obtained by securing a layer of air by means of the particles. Accordingly, the present invention includes both the case where the particles are attached coarsely and the case where they are attached densely.
  • The particles may be applied by any suitable method for example by passing the magnetic ribbon through a suspension containing the particles. Where it is intended that the particles should act as a spacer trapping a layer of air between layers or windings of a core the proportion of particles in the suspension may be chosen to be suitably low. For example where the particles are antimony pentoxide suspended in toluene they may form 1% to 10%, preferably 2% to 5%, eg about 3%, by weight of the suspension.
  • Where it is intended that the particles should be attached more densely so as to act as the insulation then a higher proportion may be used in the suspension. For example, with the same materials as above, above 20% by weight, for example 20% to 50%, e.g. about 30% by weight.
  • Thus with the present invention a magnetic ribbon and a magnetic core can be provided having excellent magnetic characteristics while securing insulating properties between ribbon layers with the space factor reduced.
  • The invention will be further described by way of non-limitative example with reference to the accompanying drawings, in which :-
    • Figs. 1 to 3 are graphs illustrating magnetic characteristics in accordance with a first embodiment of the present invention, in which
      • Fig. 1 illustrates B-H characteristics;
      • Fig. 2 illustrates the frequency characteristics of core loss; and
      • Fig. 3 illustrates the frequency characteristics of permeability;
    • Figs. 4 to 6 are graphs illustrating the magnetic characteristics in accordance with a second embodiment of the present invention, in which
      • Fig. 4 illustrates B-H characteristics;
      • Fig. 5 illustrates the frequency characteristics of core loss; and
      • Fig. 6 illustrates the frequency characteristics of permeability; and
      • Fig. 7 illustrates the outline of apparatus for attaching fine articles; and
      • Fig. 8 is a diagram schematically illustrating means for producing a toroidal type magnetic core.
  • Referring now to the accompanying drawings, a description will be given of the preferred embodiments of the present invention.
  • The magnetic ribbon referred to in the present invention is a thin magnetic strip, and, as magnetic materials, it is possible to cite the following: ferromagnetic elements such as Fe, Co, and Ni among transition metals, alloys of ferromagnetic elements, alloys of ferromagnetic elements and nonferromagnetic elements which are added to improve characteristics, ferrite, permalloy, amorphous alloys, etc. As amorphous alloys, it is possible to cite Fe-based alloys such as Fe-B, Fe-B-C, Fe-B-Si, Fe-B-Si-C, Fe-B-Si-Cr, Fe-Co-B-Si, and Fe-Ni-Mo-B, Co-based alloys such as Co-B, Co-Fe-Si-B, Co-Fe-Ni-Mo-B-Si, Co-Fe-Ni-B-Si, Co-Fe-Mn-B-Si, Co-Fe-Mn-Ni, Co-Mn-Ni-B-Si, and Co-Fe-Mn-Ni-B, and other similar alloys.
  • The conditions of inorganic fine particles that are attached to such a magnetic ribbon are that it is nonmagnetic, and that it has insulating properties. If the fine particles are magnetic and conductive, an adverse effect is exerted on magnetic characteristics, and an eddy current is liable to flow.
  • As inorganic substances used in the present invention, it is possible to cite the following: (1) inorganic substances which are stable in a natural condition, including glass (sodium silicate), mica (aluminosilicate alkali salt and phyllosilicate alkali salt), silicon carbide, calcium sulfate semi-water salt, potassium carbonate, magnesium carbonate, calcium carbonate, barium sulfate, and the like; (2) metal oxides such as aluminum oxide, boron oxide, magnesium oxide, silicon dioxide, tin dioxide, zinc oxide, zirconium dioxide, antimony pentoxide, and the like; and (3) ceramics formed of the materials cited in (2) above and double oxides such as perovskite, silicate glass, phosphate, titanic acid salt, niobium, tantalum, and tungstate; ceramics formed singly or in a combination by using such ceramic materials as nitrides, including aluminum nitride, a sintered body of aluminum oxide and nitride, boron nitride, boron nitride magnesium, boron nitride complexes, silicon nitride, silicon nitride lanthanum, and SIALON, carbides, including boron carbide, silicon carbide, boron carbide aluminum, and titanium carbide, and borides, including titanium diboride, calcium hexaboride, and lanthanum hexaboride. Among these substances, antimony pentoxide is preferably used.
  • As for the size of the fine particles of the inorganic substance, if consideration is paid to the fact that the fine particles are attached to the ribbon uniformly so as to form an insulating layer, the size of the fine particles may be small. However, if the particle size is made too small, it constitutes a factor making manufacture difficult. Meanwhile, if the particle size is too large, when the magnetic core is formed by a ribbon, the gap between the adjacent layers of the ribbon becomes too large, so that the space factor of the magnetic material becomes small. For this reason, it is preferred that the size of the fine particles is set in the range of 10 nm to 2 µm.
  • In addition, as for the amount of the fine particles attached, the fine particles may preferably be attached in such a manner that they are attached by 10⁻⁷cm³ to 2 x 10⁻­⁴cm³, more preferably 3 x 10⁻⁶cm³ - 10⁻⁵cm³, per unit area (1 cm²). If this amount attached is calculated into the weight of fine particles per unit area, although its value changes depending on the specific weight of the material of the fine particles, in the case of antimony pentoxide, the weight is 3.8 x 10⁻⁷g/cm² - 7.6 x 10⁻⁴g/cm², preferably 1.1 x 10⁻⁵g/cm² - 3.8 x 10⁻⁵g/cm².
  • Means for attaching the fine particles is so arranged that these fine particles are dispersed in water or a volatile organic solvent such as toluene, and, after this solution is applied to the ribbon surface, force or natural drying is carried out, thereby allowing the fine particles to be attached to the ribbon. The concentration of this solution determines the amount of fine particles to be attached to the ribbon. In other words, in the case of antimony pentoxide, this inorganic substance may be dispersed in toluene in a colloidal state at a rate of from 0.1 to 30 wt% with respect to toluene. 3 wt% or thereabouts in this range is also effective, a decline in the space factor is practically nil, and the magnetic characteristics do not deteriorate. The thickness of the film of the solution applied is preferably 10 µm or less in determining the aforementioned amount of fine particles to be attached. In addition, a drying furnace may be used for evaporation of the solvent depending on the solvent, and drying may be carried out at 100°C or above.
  • With respect to the magnetic ribbon, or an amorphous ribbon, in particular, annealing may be carried out for 0.­5 - 5 hours at the temperature of 300 - 500°C in an inert gas atmosphere such as nitrogen so as to eliminate strain, as required. This annealing may be effected after the ribbon is wound or laminated into a magnetic core, or may be effected in the state of the ribbon. In particular, when annealing is effected at a temperature 10 to 50°C higher than the Curie point, a magnetic core exhibiting excellent characteristics with respect to high frequencies can be obtained. Incidentally, annealing may be effected in a magnetic field or in a nonmagnetic field.
  • In addition, when the amorphous magnetic core with the ribbon wound therearound or laminated thereon is annealed since the fine particles disposed between adjacent ribbon layers are powders, the magnetic core is not subjected to linear expansion. The fine particles rather exhibit the action of absorbing the stress accompanying the shrinkage of the amorphous ribbon.
  • On the basis of the foregoing, a description will now be given of a method of producing a magnetic core in accordance with the present invention.
  • First, a magnetic ribbon and a solution containing fine particles are prepared. The solution containing the fine particles is applied to at lest one surface of the magnetic ribbon by any of the various methods of application, and the solvent is allowed to dry. The resultant magnetic ribbon with the fine particles attached thereto is wound under tension, thereby obtaining a toroidal-type magnetic core. Finally, annealing for eliminating strain is carried out, as necessary. Incidentally, tension applied at the time of winding is preferably 0.05 o 2 kg.
  • Meanwhile, when a laminated type magnetic core is produced, the ribbon with fine particles attached thereto is cut into a predetermined configuration, and the cut pieces are laminated so as to form the magnetic core. Annealing which is carried out as necessary may be effected prior to the lamination or after the magnetic core has been formed subsequent to the lamination.
  • Examples of the present invention will be described hereafter.
  • By using the apparatus shown in Fig. 7, an amorphous ribbon 1a (2605S-2, Fe₇₈-B₁₃-Si₉, 10 mm width) made by Allied Corp. is fed forward into a colloidal solution 2 of antimony pentoxide. When the amorphous ribbon 1a is lifted up, the amorphous ribbon 1a is clamped by a pair of bar coaters 3 so as to allow excess solution to drop. Then, while the ribbon 1a is being dried with hot air by means of a hot air drier 4, the ribbon 1a was taken up. As for the colloidal solution 2 of antimony pentoxide, toluene was used as the solvent, and 3 wt% of antimony was dispersed with respect to toluene 97 wt%.
  • Subsequently, as shown in Fig. 8, the ribbon 1b with the particles attached thereto was fed forward via a roller 5, and was wound under tension in a final stage, thereby forming an amorphous magnetic core 6. A plurality of magnetic cores having the same dimensions were then formed, and were subjected to annealing for two hours at 435°C in a nitrogen atmosphere.
  • With respect to the magnetic cores thus obtained, measurements were made of the B-H characteristics, frequency characteristics of core loss, and frequency characteristics of permeability. As for the B-H characteristics, measurements were made of two cases: one in which a magnetic field of 10 oersted (Oe), and the other in which a magnetic field of 1 oersted (Oe) was applied.
  • In addition, a colloidal solution in which 30 wt% of antimony pentoxide was dispersed with respect to 70 wt% of toluene was applied to the ribbon 1a, and measurements were similarly made. The detailed conditions in the respective examples were as follows:
  • (1) Example 1 (3 wt% solution) (a) Magnetic core:
  • a toroidal core with the aforementioned ribbon wound therearound
    Inside diameter: 23.00 mm
    Outside diameter: 37.00 mm
    Height: 10.00 mm
    Mass: 42.00 g
    Density of the material: 7.18 g/m³
    Volume: 5.850 x 10⁻⁶ (m³)
    Effective sectional area: 6.207 x 10⁻⁵ (m²)
    Mean magnetic path length: 9.425 x 10⁻² (m)
    Space factor: 88.67% (ratio of the volume of the ribbon to the total volume)
    Tension during the magnetic ribbon winding: 0.8 kg
  • (b) Colloidal solution applied
  • Organic solvent: toluene, 100 wt%
    Fine particles: antimony pentoxide, 3 wt%
  • (c) Results
  • * B-H characteristics are shown in Fig. 1.
    * Frequency characteristics of core loss are shown in Fig. 2.
    The number of turns of the primary winding around the core was 5, while the number of turns of the secondary winding was 10.
    * Frequency characteristics of permeability are shown in Fig. 3.
    The number of turns of the primary winding around the core was 10.
    Measured magnetic field: 5 mOe
    Measured current: 2.65173 mA
  • (2) Example 2 (30wt% solution) (a) Magnetic core:
  • a toroidal core with the aforementioned ribbon wound therearound
    Inside diameter: 23.00 mm
    Outside diameter: 37.00 mm
    Height: 10.00 mm
    Mass: 25.57 g
    Density of the material: 7.18 g/m³
    Volume: 3.561 x 10⁻⁶ (m³)
    Effective sectional area: 3.779 x 10⁻⁵ (m²)
    Mean magnetic path length: 9.425 x 10⁻² (m)
    Space factor: 53.98%
    Tension during the magnetic ribbon winding: 0.8 kg
  • (b) Colloidal solution applied
  • Organic solvent: toluene, 70 wt%
    Fine particles: antimony pentoxide, 30 wt%
  • (c) Results
  • * B-H characteristics are shown in Fig. 4.
    * Frequency characteristics of core loss are shown in Fig. 5.
    The number of turns of the primary winding around the core was 5, while the number of turns of the secondary winding was 10.
    * Frequency characteristics of permeability are shown in Fig. 6.
    The number of turns of the primary winding around the core was 10.
    Measured magnetic field: 5 mOe
    Measured current: 2.65173 mA
  • From the foregoing results, it can be appreciated that the magnetic cores of the Examples display a hysteresis which is closer to a linear configuration, and that the core loss is low as a whole, and a rise in the high-­frequency component can be reduced to a low level. A substantially fixed permeability was obtained up to 200 kHz.
  • As described above, in accordance with the present invention, since the above-described arrangement is adopted, it is possible to improve the magnetic characteristics at a frequency higher than 10 kHz, and the space factor can be made as large as possible, thereby making contributions to making the magnetic core compact.

Claims (10)

1. A magnetic ribbon on at least one surface of which particles formed of a nonmagnetic substance having insulating properties are attached.
2. A magnetic ribbon according to claim 1, wherein said magnetic ribbon is formed of an amorphous metal.
3. A magnetic ribbon according to claim 1 or 2 wherein the particles are formed of an inorganic substance.
4. A magnetic ribbon according to claim 1, 2 or 3, wherein said non-magnetic substance is a metal oxide, and the size of said particles is 10nm to 2µm.
5. A magnetic ribbon according to any of claims 1, 2, 3 or 4, wherein said magnetic ribbon is subjected to annealing for 0.5 - 5 hours at a temperature of 300 - 500°C in an inert gas atmosphere.
6. A magnetic ribbon according to any one of the preceding claims wherein the particles are attached so as to secure a layer of air.
7. A magnetic ribbon are to any one of the preceding claims wherein the particles are attached at such a surface density to act as spacers so that when the ribbon is wound or laminated with other ribbons, air and/or the particles electrically insulate the layers from each other.
8. A magnetic core around which said magnetic ribbon according to any of claims 1 to 7 is wound or on which said magnetic ribbon is laminated.
9. A magnetic core around which said magnetic ribbon according to any of claims 1 to 4 is wound or on which said magnetic ribbon is laminated, and which is subsequently subjected to annealing for 0.5 - 5 hours at a temperature of 300 - 500°C in an inert gas atmosphere.
10. An electrical or electronic device including a magnetic core according to claim 9.
EP89303542A 1988-04-11 1989-04-11 Magnetic ribbon and magnetic core Expired - Lifetime EP0337716B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP88694/88 1988-04-11
JP63088694A JP2716064B2 (en) 1988-04-11 1988-04-11 Magnetic ribbon and magnetic core

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EP0337716A2 true EP0337716A2 (en) 1989-10-18
EP0337716A3 EP0337716A3 (en) 1990-09-19
EP0337716B1 EP0337716B1 (en) 1995-03-01

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EP (1) EP0337716B1 (en)
JP (1) JP2716064B2 (en)
KR (1) KR920005490B1 (en)
AT (1) ATE119309T1 (en)
CA (1) CA1340795C (en)
DE (1) DE68921363T2 (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1991018404A1 (en) * 1990-05-18 1991-11-28 Allied-Signal Inc. Magnetic cores utilizing metallic glass ribbons and mica paper interlaminar insulation
EP0480265A1 (en) * 1990-10-03 1992-04-15 Nippon Steel Corporation Method of producing permalloy cores
EP0625786A2 (en) * 1993-05-21 1994-11-23 Hitachi Metals, Ltd. Nano-crystalline soft magnetic alloy ribbon with insulation coating; magnetic core therefrom and applications therewith
WO2006014632A2 (en) * 2004-07-22 2006-02-09 Axcelis Technologies, Inc. Improved magnet for scanning ion beams
US9331493B2 (en) 2012-01-13 2016-05-03 Honda Motor Co., Ltd. Electric load control apparatus
US11715591B2 (en) 2020-03-27 2023-08-01 Proterial, Ltd. Method for manufacturing a wound magnetic core

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2023031770A (en) 2021-08-25 2023-03-09 Tdk株式会社 Magnetic alloy ribbon, laminate and magnetic core

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JPS618903A (en) * 1984-06-25 1986-01-16 Kawasaki Steel Corp Characteristics of amorphous alloy thin belt and improvement of dieing workability thereof
JPS6210278A (en) * 1985-07-09 1987-01-19 Kawasaki Steel Corp Thin amorphous alloy strip having excellent paramagnetic permeability
JPS6261308A (en) * 1985-09-11 1987-03-18 Toshiba Corp Heat treatment of amorphous wound core
EP0214305A1 (en) * 1985-02-27 1987-03-18 Kawasaki Steel Corporation Process for the production of a laminate of thinamorphous alloy strip and a core made of thin amorphous alloy strip
JPS62188209A (en) * 1986-02-13 1987-08-17 Tdk Corp Manufacture of wound core

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JPS61181114A (en) * 1985-02-07 1986-08-13 Toshiba Corp Manufacture of rolled iron core
JPS61198611A (en) * 1985-02-27 1986-09-03 Kawasaki Steel Corp Manufacture of transformer with amorphous alloy thin band core
JPS6265403A (en) * 1985-09-18 1987-03-24 Kawasaki Steel Corp Improving magnetic characteristics of amorphous alloy thin band

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JPS618903A (en) * 1984-06-25 1986-01-16 Kawasaki Steel Corp Characteristics of amorphous alloy thin belt and improvement of dieing workability thereof
EP0214305A1 (en) * 1985-02-27 1987-03-18 Kawasaki Steel Corporation Process for the production of a laminate of thinamorphous alloy strip and a core made of thin amorphous alloy strip
JPS6210278A (en) * 1985-07-09 1987-01-19 Kawasaki Steel Corp Thin amorphous alloy strip having excellent paramagnetic permeability
JPS6261308A (en) * 1985-09-11 1987-03-18 Toshiba Corp Heat treatment of amorphous wound core
JPS62188209A (en) * 1986-02-13 1987-08-17 Tdk Corp Manufacture of wound core

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PATENT ABSTRACTS OF JAPAN, vol. 10, no. 145 (E-407)[2202], 28th May 1986; & JP-A-61 008 903 (KAWASAKI SEITETSU K.K.) 16-01-1986 *
PATENT ABSTRACTS OF JAPAN, vol. 11, no. 185 (C-428)[2632], 13th June 1987; & JP-A-62 010 278 (KAWASAKI STEEL CORP.) 19-01-1987 *
PATENT ABSTRACTS OF JAPAN, vol. 11, no. 249 (E-532)[2696], 13th August 1987; & JP-A-62 061 308 (TOSHIBA CORP.) 18-03-1987 *
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Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1991018404A1 (en) * 1990-05-18 1991-11-28 Allied-Signal Inc. Magnetic cores utilizing metallic glass ribbons and mica paper interlaminar insulation
EP0480265A1 (en) * 1990-10-03 1992-04-15 Nippon Steel Corporation Method of producing permalloy cores
EP0625786A2 (en) * 1993-05-21 1994-11-23 Hitachi Metals, Ltd. Nano-crystalline soft magnetic alloy ribbon with insulation coating; magnetic core therefrom and applications therewith
EP0625786A3 (en) * 1993-05-21 1995-01-25 Hitachi Metals Ltd Nano-crystalline soft magnetic alloy ribbon with insulation coating; magnetic core therefrom and applications therewith.
US5486404A (en) * 1993-05-21 1996-01-23 Hitachi Metals, Ltd. Nano-crystalline soft magnetic alloy ribbon with insulation coating and magnetic core made therefrom and pulse generator, laser unit and accelerator therewith
WO2006014632A2 (en) * 2004-07-22 2006-02-09 Axcelis Technologies, Inc. Improved magnet for scanning ion beams
WO2006014632A3 (en) * 2004-07-22 2006-04-20 Axcelis Tech Inc Improved magnet for scanning ion beams
US9331493B2 (en) 2012-01-13 2016-05-03 Honda Motor Co., Ltd. Electric load control apparatus
US11715591B2 (en) 2020-03-27 2023-08-01 Proterial, Ltd. Method for manufacturing a wound magnetic core

Also Published As

Publication number Publication date
EP0337716A3 (en) 1990-09-19
CA1340795C (en) 1999-10-19
JPH01259510A (en) 1989-10-17
KR890016591A (en) 1989-11-29
DE68921363D1 (en) 1995-04-06
ATE119309T1 (en) 1995-03-15
EP0337716B1 (en) 1995-03-01
KR920005490B1 (en) 1992-07-06
JP2716064B2 (en) 1998-02-18
DE68921363T2 (en) 1995-07-13

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