[go: up one dir, main page]

WO2004043633A1 - Fe-Si ALLOY POWDER CORES AND FABRICATION PROCESS THEREOF - Google Patents

Fe-Si ALLOY POWDER CORES AND FABRICATION PROCESS THEREOF Download PDF

Info

Publication number
WO2004043633A1
WO2004043633A1 PCT/KR2003/002430 KR0302430W WO2004043633A1 WO 2004043633 A1 WO2004043633 A1 WO 2004043633A1 KR 0302430 W KR0302430 W KR 0302430W WO 2004043633 A1 WO2004043633 A1 WO 2004043633A1
Authority
WO
WIPO (PCT)
Prior art keywords
alloy powder
smd
core
binder
present
Prior art date
Application number
PCT/KR2003/002430
Other languages
French (fr)
Inventor
Kyu-Jin Kim
Jin-Young Park
Original Assignee
Humanelecs Co., Ltd.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Humanelecs Co., Ltd. filed Critical Humanelecs Co., Ltd.
Priority to AU2003280872A priority Critical patent/AU2003280872A1/en
Publication of WO2004043633A1 publication Critical patent/WO2004043633A1/en

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/02—Compacting only
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C33/00—Making ferrous alloys
    • C22C33/02—Making ferrous alloys by powder metallurgy
    • C22C33/0257—Making ferrous alloys by powder metallurgy characterised by the range of the alloying elements
    • C22C33/0264—Making ferrous alloys by powder metallurgy characterised by the range of the alloying elements the maximum content of each alloying element not exceeding 5%
    • C22C33/0271—Making ferrous alloys by powder metallurgy characterised by the range of the alloying elements the maximum content of each alloying element not exceeding 5% with only C, Mn, Si, P, S, As as alloying elements, e.g. carbon steel
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
    • B22F1/10—Metallic powder containing lubricating or binding agents; Metallic powder containing organic material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
    • B22F1/10—Metallic powder containing lubricating or binding agents; Metallic powder containing organic material
    • B22F1/102—Metallic powder coated with organic material
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C33/00—Making ferrous alloys
    • C22C33/02—Making ferrous alloys by powder metallurgy
    • C22C33/0257—Making ferrous alloys by powder metallurgy characterised by the range of the alloying elements
    • C22C33/0278—Making ferrous alloys by powder metallurgy characterised by the range of the alloying elements with at least one alloying element having a minimum content above 5%
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
    • H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
    • H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
    • H01F1/12—Magnets 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
    • H01F1/14—Magnets 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
    • H01F1/147—Alloys characterised by their composition
    • H01F1/14766—Fe-Si based alloys
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
    • H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
    • H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
    • H01F1/12—Magnets 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
    • H01F1/14—Magnets 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
    • H01F1/20—Magnets 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 particles, e.g. powder
    • H01F1/22—Magnets 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 particles, e.g. powder pressed, sintered, or bound together
    • H01F1/24—Magnets 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 particles, e.g. powder pressed, sintered, or bound together the particles being insulated
    • H01F1/26—Magnets 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 particles, e.g. powder pressed, sintered, or bound together the particles being insulated by macromolecular organic substances
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F17/00—Fixed inductances of the signal type
    • H01F17/04—Fixed inductances of the signal type with magnetic core
    • H01F17/043—Fixed inductances of the signal type with magnetic core with two, usually identical or nearly identical parts enclosing completely the coil (pot cores)
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F3/00—Cores, Yokes, or armatures
    • H01F3/08—Cores, Yokes, or armatures made from powder
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F41/00—Apparatus 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
    • H01F41/02—Apparatus 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
    • H01F41/0206—Manufacturing of magnetic cores by mechanical means
    • H01F41/0246—Manufacturing of magnetic circuits by moulding or by pressing powder
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/24—After-treatment of workpieces or articles
    • B22F2003/248—Thermal after-treatment
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F2998/00—Supplementary information concerning processes or compositions relating to powder metallurgy
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F2998/00—Supplementary information concerning processes or compositions relating to powder metallurgy
    • B22F2998/10—Processes characterised by the sequence of their steps
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F17/00—Fixed inductances of the signal type
    • H01F17/04—Fixed inductances of the signal type with magnetic core
    • H01F2017/048—Fixed inductances of the signal type with magnetic core with encapsulating core, e.g. made of resin and magnetic powder
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F27/00—Details of transformers or inductances, in general
    • H01F27/02—Casings
    • H01F27/027—Casings specially adapted for combination of signal type inductors or transformers with electronic circuits, e.g. mounting on printed circuit boards
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F27/00—Details of transformers or inductances, in general
    • H01F27/28—Coils; Windings; Conductive connections
    • H01F27/29—Terminals; Tapping arrangements for signal inductances
    • H01F27/292—Surface mounted devices

Definitions

  • the present invention relates to an SMD (surface mounting device) core using Fe-Si alloy powder and fabrication method thereof, by which excellent magnetic properties of the SMD core appear in radio frequency band, the SMD core having saturated magnetic flux density and effective magnetic permeability (or inductance) better than those of the previous SMD cores such as pure ion, Sendust (Fe 8 4Si ⁇ o l 6 ) , and the like can be fabricated, and the new SMD core can be mass-produced with low process or raw material costs.
  • the requested magnetic properties are implemented using pure iron or Sendust alloy powder.
  • the pure iron powder is applicable within a low magnetic permeability area only due to the inferior magnetic properties (especially, effective magnetic permeability, magnetic loss, etc.) despite the facilitation of the fabrication.
  • Sendust alloy powder high brittleness of the powder makes the SMD cores broken with ease in fabrication despite its excellent soft magnetic property.
  • High Flux (Fe 5 oNi 50 ) or MMP (moly-permalloy powder) alloy power having excellent ductility and soft magnetic properties is appropriately mixed with the pure iron powder or Sendust alloy powder, which raises the costs of production due to expensive raw materials.
  • the related art annealing needs a considerably high annealing temperature over 1,100°C, which brings about oxidation or sintering of Fe-Si alloy powder particles in the process of annealing.
  • the sintering between the Fe-Si alloy powder particles results in the degraded radio frequency characteristics as well as the superior soft magnetic properties of the final Fe-Si alloy powder.
  • the related art final Fe-Si alloy powder has difficulty in application to a band over several hundreds kHz.
  • the annealing has to be performed at high temperature, thereby increasing costs of fabrication.
  • the present invention is directed to an SMD (surface mounting device) core using Fe-Si alloy powder and fabrication method thereof that substantially obviate one or more of the problems due to limitations and disadvantages of the related art.
  • An object of the present invention is to provide an SMD core using Fe-Si alloy powder and fabrication method thereof, by which excellent magnetic properties of the SMD core appear in radio frequency band, new SMD cores having cohesive strength, saturated magnetic flux density, and effective magnetic permeability (or inductance) better than those of the previous SMD cores such as pure ion, Sendust, and the like can be fabricated, and the new SMD cores can be mass-produced with low process or raw material costs.
  • Another object of the present invention is to provide an SMD core using Fe-Si alloy powder and fabrication method thereof, in which annealing is performed at a low temperature to economically fabricate Fe-Si alloy powder having the above-mentioned properties.
  • a method of fabricating an SMD core using Fe-Si alloy powder includes a step (a) of preparing a binder solution by dissolving a binder in an organic solvent or water, a step (b) of preparing a composite particle powder by coating the binder solution on a Fe-Si alloy powder surface, and a step (c) of molding the composite particle powder.
  • the method further includes an annealing step of performing annealing on the composite particle powder at 400-800°C after the step (c) .
  • the binder in the step (a) is selected from the group consisting of polyimide based resin, phenol based resin, and sodium silicate and wherein a content of the binder is 0.2-3. Qwt% of total mass of the binder and the Fe-Si alloy powder.
  • a molding pressure in the step (c) is 5-20 ton/cm 2 and a molding time is 5-30 seconds.
  • a Si content of the Fe-Si alloy powder is 3 ⁇ 0wt%
  • a Fe content of the Fe-Si alloy powder is 90 ⁇ 97wt%
  • a particle diameter of the Fe-Si alloy powder is 10 ⁇ 150um.
  • a Fe- Si alloy powder core is fabricated by a method of fabricating an SMD core using Fe-Si alloy powder according to the present invention.
  • Fig. 1 is a flowchart of a method of fabricating an SMD core using Fe-Si alloy powder according to one embodiment of the present invention
  • Fig. 2 shows development views and a perspective view of an SMD core body using Fe-Si alloy powder according to one embodiment of the present invention.
  • Fig. 3 shows development views of an SMD core cover using Fe-Si alloy powder according to one embodiment of the present invention.
  • Fig. 1 is a flowchart of a method of fabricating an SMD core using Fe-Si alloy powder according to one embodiment of the present invention.
  • a method of fabricating an SMD core using Fe-Si alloy powder includes a coating step 10 of coating the Fe-Si alloy powder, a pressurization molding step 20 of performing pressurization molding on the coated Fe-Si alloy powder to fabricate the SMD core using the Fe-Si alloy powder, and an annealing step 30 of annealing the SMD core fabricated by the pressurization molding step 20 to give superior soft magnetic properties to the annealed SMD core and to increase cohesive strength thereof.
  • the coating step 10 is performed in a manner that the Fe-Si alloy powder is coated with a binder.
  • the present invention can be prepared by gas ato ization, water atomization, or the like. And, the present invention uses the alloy powder prepared by high-pressure water atomization.
  • the particle diameter of the Fe-Si alloy powder is preferably below 150 ⁇ m.
  • a particle distribution of the Fe- Si alloy powder prepared by the high-pressure water atomization is 5 ⁇ 150 ⁇ m, and an average particle diameter is about 20 ⁇ m.
  • the Si content is preferably 3 ⁇ 10wt%.
  • a softening point of the binder should be lower than an annealing temperature of the Fe-Si alloy powder for revealing high magnetic permeability and a sample, which has a predetermined cohesive strength at room temperature, is used to suppress crack generation while maintaining a shape of the core by a molding pressure on performing the pressurization molding at the room temperature.
  • the binder is preferably selected from the group consisting of polyimide based ther o-hardening resin, phenol based thermo-hardening resin, and inorganic sodium silicate.
  • An amount of the binder is preferably limited to 0.2-3.0wt% of total mass. If the amount of the binder is below 0.2wt%, the cohesive strength is so weak that the surface cracks frequently occur in molding of the alloy powder. If the amount of the binder exceeds 3.0wt%, the cohesive strength between the alloy powder particles increases but the amount of the binder over the molding weight becomes excessive to degrade the soft magnetic properties. And, the total mass means totaled mass of the binder and alloy powder constructing the fabricated core.
  • the binder In order to coat the Fe-Si alloy powder surface with the binder, the binder is dissolved in an organic solvent or water to prepare a binder solution. The Fe-Si alloy powder is then mixed with the binder solution so that the Fe-Si alloy powder surface is uniformly coated with the binder to the thickness below 0. I ⁇ m for liquid phase coating 10.
  • the pressurization molding step 20 of pressurizing the coated alloy powder in a mold is executed to mold an SMD core.
  • the molding pressure is preferably below 20 ton/cm 2 . If the molding pressure exceeds 20 ton/cm 2 , the increased abrasion and the frequent occurrence of surface scratches of the mold shorten a replacement period of the mold to increase the costs of production despite the enhancement of magnetic properties of the SMD core. On the other hand, if the molding pressure is smaller than 5 ton/cm 2 , molding density is lowered to degrade the magnetic properties.
  • the annealing step 30 of the molded core is performed to acquire the revelation of the excellent soft magnetic properties and the enhancement of the cohesive strength by removing the stresses generated from the preparation and molding of the powder to control the microstructure of the core.
  • Annealing conditions are varied according to the usage of the core.
  • a material of high magnetic permeability (A L value: over 90nH/N 2 at 100kHz) is annealed at 400-800 °C, whereas a material of low magnetic permeability (A L value: over 90nH/N 2 at 100kHz) is not annealed.
  • the magnetic permeability property is reduced below 400°C, and the binder is resolved over 800°C to degrade the insulating property between the powder particles.
  • Annealing ambience is preferably provided by a non-oxidizing gas such as N 2 , Ar, and the like or a reducing gas such as H 2 , etc.
  • annealing time is preferably set to 10-120 minutes. If the annealing time is too short, the stress fails to be sufficiently removed. If the annealing time is too long, productivity is reduced.
  • a solution prepared by dissolving polyimide as a binder amounting to about 0.85wt% of total mass of Fe-Si alloy powder in methylene chloride is poured on Fe 93 .5Si6.5 (wt%) alloy powder (average particle diameter: 20 ⁇ m, particle distribution: 5 ⁇ 150 ⁇ m) prepared by water atomization to be mixed with each other.
  • the mixed solution is then dried so that polyimide is uniformly coated on a surface of the Fe-Si alloy powder to the thickness below O.l ⁇ m to prepare powder of composite particles.
  • the polyimide-coated Fe-Si alloy powder is molded at a pressure of about 5 ton/cm 2 in a mold, and is then annealed at 740 °C for about 60 minutes at an ambience of N 2 or Ar gas to fabricate a Fe-Si alloy powder SMD core.
  • the SMD core generally includes a body and a cover.
  • a body and a cover of the SMD core according to the present invention are fabricated using Fe-Si alloy powder by the above-explained method and are shown in Fig. 2 and Fig. 3, respectively.
  • Fig. 2 shows development views and a perspective view of an SMD core body using Fe-Si alloy powder according to one embodiment of the present invention
  • Fig. 3 shows development views of an SMD core cover using Fe-Si alloy powder according to one embodiment of the present invention.
  • a size of the fabricated SMD core is shown in the drawings. Shape and size of the SMD core fabricated by the method of fabricating the SMD core using Fe-Si alloy powder according to the present invention are not limited to the above-described embodiment of the present invention.
  • Average crystalline particle diameter, density, saturated magnetic flux density, and A L value coefficient ratio (A L lMHz/A L lkHz) in various frequency bands for the fabricated SMD core are shown in Table 1.
  • an average size of a powder particle diameter indicates a value of average particle diameters analyzed by Laser Particle Sizer and SEM (scanning electron microscope) , the density of the core is computed by dividing actual core weight by core volume, the saturated magnetic flux density (Bs) is measured under an external magnetic field of 5,000 Oe using VSM (vibrating sample magnetometer) , and the A L value is measured under an external magnetic field of 10 mOe at each frequency band using LCR meter. And, the A L value coefficient ratio (A L lMHz/A L lkHz) indicates a ratio between A values measured at 1MHz and 1kHz, respectively.
  • a second embodiment according to the present invention is performed in the same manner of the first embodiment according to the present invention except that eg 6 . 5 Si 3 . 5 (wt%) alloy powder (average particle diameter: 23 ⁇ m, particle distribution: 5 ⁇ 150 ⁇ m) prepared by water atomization is used as the Fe-Si alloy powder in the first embodiment of the present invention and that the amount of polyimide as the binder is changed into 0.5wt%.
  • Third Embodiment A third embodiment according to the present invention is performed in the same manner of the first embodiment according to the present invention except that Fe 9 Sis(wt%) alloy powder (average particle diameter: 23 ⁇ m, particle distribution: 5 ⁇ 150 ⁇ m) prepared by water atomization is used as the Fe-Si alloy powder in the first embodiment of the present invention.
  • a fourth embodiment according to the present invention is performed in the same manner of the first embodiment according to the present invention except that the amount of polyimide as the binder is changed into 1.2wt%.
  • a fifth embodiment according to the present invention is performed in the same manner of the first embodiment according to the present invention except that the amount of sodium silicate used as the binder is 0.85wt%.
  • Sixth Embodiment A sixth embodiment according to the present invention is performed in the same manner of the first embodiment according to the present invention except that the amount of phenol based resin used as the binder is 0.85wt%.
  • Seventh Embodiment A seventh embodiment according to the present invention is performed in the same manner of the first embodiment according to the present invention except that annealing is not performed in molding the SMD core.
  • Eighth Embodiment An eighth embodiment according to the present invention is performed in the same manner of the first embodiment according to the present invention except that the annealing temperature is set to 400°C.
  • a ninth embodiment according to the present invention is performed in the same manner of the first embodiment according to the present invention except that the annealing temperature is set to 800 °C.
  • a tenth embodiment according to the present invention is performed in the same manner of the first embodiment according to the present invention except that the molding pressure is set to 12 ton/cm 2 .
  • a first comparison example is performed in the same manner of the first embodiment according to the present invention except that Sendust (Fe84.1Si10.1 l5.8) alloy powder (average particle diameter: 28 ⁇ m, particle distribution: 5 ⁇ 150 ⁇ m) prepared by high-pressure water atomization is used as a conventional SMD core raw material for high magnetic permeability.
  • Sendust Fe84.1Si10.1 l5.8 alloy powder (average particle diameter: 28 ⁇ m, particle distribution: 5 ⁇ 150 ⁇ m) prepared by high-pressure water atomization is used as a conventional SMD core raw material for high magnetic permeability.
  • Second comparison Example A second comparison example is performed in the same manner of the first embodiment according to the present invention except that pure iron (Fe) powder (average particle diameter: 75 ⁇ m, particle distribution: 10 ⁇ 150 ⁇ m) is used as a conventional SMD core raw material for low magnetic permeability.
  • pure iron (Fe) powder average particle diameter: 75 ⁇ m, particle distribution: 10 ⁇ 150 ⁇ m
  • the binder (polyimide, phenol, or sodium silicate) of high rigidity is mixed with Fe-Si based alloy powder containing 3.0 ⁇ 6.5wt% Si to prepare composite powder, and the composite powder is then molded at a pressure below 15 ton/cm 2 .
  • the molding density becomes at least 6.3, whereby the saturated magnetic flux density becomes at least 1.5T.
  • the A L value at 100 kHz is at least 90 nH/N 2 if annealing is skipped, whereas it becomes at least 100 nH/N 2 if annealing is performed.
  • the A L value at 100 kHz is at least 125 nH/N 2 and the A L value coefficient ratio (A L MHZ /A L kH z) becomes at least 0.98.
  • Such an A L value is superior to that of the commercialized SMD core product using Sendust alloy powder.
  • the corresponding saturated magnetic flux density is 1.5 times higher than that of the commercialized SMD core product using Sendust alloy powder.
  • an SMD core using Fe-Si alloy powder and fabrication method thereof according to the present invention excellent magnetic properties of the SMD core appear in radio frequency band, the SMD core having excellent cohesive strength, saturated magnetic flux density, and effective magnetic permeability (or inductance) can be fabricated, and the SMD core having both of the excellent frequency characteristics and the soft magnetic properties can be mass-produced with low process or raw material costs by performing annealing within a range of low temperature between 400-800 °C in fabricating a material of high magnetic permeability (A value: over 110 nH/N 2 at 100 kHz) .

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Power Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Materials Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Dispersion Chemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Electromagnetism (AREA)
  • Powder Metallurgy (AREA)

Abstract

Disclosed is an SMD (surface mounting device) core using Fe-Si alloy powder and fabrication method thereof, by which excellent magnetic properties of the SMD core appear in radio frequency band, the SMD core having saturated magnetic flux density and effective magnetic permeability (or inductance) better than those of the previous SMD cores such as pure ion, Sendust (Fe84Si10Al6), and the like can be fabricated, and the new SMD core can be mass-produced with low process or raw material costs. The present invention includes a step: (a) of preparing a binder solutin by dissolving a binder in an organic solvent or water; a step (b) of preparing a composite particle powder by coating the binder solution on a Fe-Si alloy powder surface, and a step (c) of molding the composite particle powder.

Description

Fe-Si Alloy Powder Cores and Fabrication Process thereof
TECHNICAL FIELD
The present invention relates to an SMD (surface mounting device) core using Fe-Si alloy powder and fabrication method thereof, by which excellent magnetic properties of the SMD core appear in radio frequency band, the SMD core having saturated magnetic flux density and effective magnetic permeability (or inductance) better than those of the previous SMD cores such as pure ion, Sendust (Fe84Siιo l6) , and the like can be fabricated, and the new SMD core can be mass-produced with low process or raw material costs. BACKGROUND ART Generally, in case of fabricating an SMD core by molding and annealing according to a related art, the requested magnetic properties are implemented using pure iron or Sendust alloy powder. Yet, in case of using pure iron powder, the pure iron powder is applicable within a low magnetic permeability area only due to the inferior magnetic properties (especially, effective magnetic permeability, magnetic loss, etc.) despite the facilitation of the fabrication. And, in case of using Sendust alloy powder, high brittleness of the powder makes the SMD cores broken with ease in fabrication despite its excellent soft magnetic property. To overcome such problems, High Flux (Fe5oNi50) or MMP (moly-permalloy powder) alloy power having excellent ductility and soft magnetic properties is appropriately mixed with the pure iron powder or Sendust alloy powder, which raises the costs of production due to expensive raw materials.
Moreover, the related art annealing needs a considerably high annealing temperature over 1,100°C, which brings about oxidation or sintering of Fe-Si alloy powder particles in the process of annealing. The sintering between the Fe-Si alloy powder particles results in the degraded radio frequency characteristics as well as the superior soft magnetic properties of the final Fe-Si alloy powder. Hence, the related art final Fe-Si alloy powder has difficulty in application to a band over several hundreds kHz. Besides, the annealing has to be performed at high temperature, thereby increasing costs of fabrication.
DISCLOSURE OF THE INVENTION
Accordingly, the present invention is directed to an SMD (surface mounting device) core using Fe-Si alloy powder and fabrication method thereof that substantially obviate one or more of the problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide an SMD core using Fe-Si alloy powder and fabrication method thereof, by which excellent magnetic properties of the SMD core appear in radio frequency band, new SMD cores having cohesive strength, saturated magnetic flux density, and effective magnetic permeability (or inductance) better than those of the previous SMD cores such as pure ion, Sendust, and the like can be fabricated, and the new SMD cores can be mass-produced with low process or raw material costs.
Another object of the present invention is to provide an SMD core using Fe-Si alloy powder and fabrication method thereof, in which annealing is performed at a low temperature to economically fabricate Fe-Si alloy powder having the above-mentioned properties.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims thereof as well as the appended drawings .
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, a method of fabricating an SMD core using Fe-Si alloy powder according to the present invention includes a step (a) of preparing a binder solution by dissolving a binder in an organic solvent or water, a step (b) of preparing a composite particle powder by coating the binder solution on a Fe-Si alloy powder surface, and a step (c) of molding the composite particle powder. Preferably, the method further includes an annealing step of performing annealing on the composite particle powder at 400-800°C after the step (c) .
And, the binder in the step (a) is selected from the group consisting of polyimide based resin, phenol based resin, and sodium silicate and wherein a content of the binder is 0.2-3. Qwt% of total mass of the binder and the Fe-Si alloy powder.
Moreover, a molding pressure in the step (c) is 5-20 ton/cm2 and a molding time is 5-30 seconds. Besides, a Si content of the Fe-Si alloy powder is 3~0wt%, a Fe content of the Fe-Si alloy powder is 90~97wt%, and a particle diameter of the Fe-Si alloy powder is 10~150um.
To further achieve these and other advantages and in accordance with the purpose of the present invention, a Fe- Si alloy powder core is fabricated by a method of fabricating an SMD core using Fe-Si alloy powder according to the present invention. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.
In the drawings :
Fig. 1 is a flowchart of a method of fabricating an SMD core using Fe-Si alloy powder according to one embodiment of the present invention;
Fig. 2 shows development views and a perspective view of an SMD core body using Fe-Si alloy powder according to one embodiment of the present invention; and
Fig. 3 shows development views of an SMD core cover using Fe-Si alloy powder according to one embodiment of the present invention.
BEST MODE FOR CARRYING OUT THE INVENTION Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.
Fig. 1 is a flowchart of a method of fabricating an SMD core using Fe-Si alloy powder according to one embodiment of the present invention.
Referring to Fig. 1, a method of fabricating an SMD core using Fe-Si alloy powder according to the present invention includes a coating step 10 of coating the Fe-Si alloy powder, a pressurization molding step 20 of performing pressurization molding on the coated Fe-Si alloy powder to fabricate the SMD core using the Fe-Si alloy powder, and an annealing step 30 of annealing the SMD core fabricated by the pressurization molding step 20 to give superior soft magnetic properties to the annealed SMD core and to increase cohesive strength thereof.
The coating step 10 is performed in a manner that the Fe-Si alloy powder is coated with a binder. The Fe-Si alloy powder used in the method of fabricating the SMD core using the Fe-Si alloy powder according to one embodiment of the W
present invention can be prepared by gas ato ization, water atomization, or the like. And, the present invention uses the alloy powder prepared by high-pressure water atomization. In fabricating the Fe-Si alloy powder, if a particle diameter of the Fe-Si alloy powder is equal to or greater than 150μm, the soft magnetic properties are enhanced but the RF characteristics are degraded. Hence, the particle diameter of the Fe-Si alloy powder is preferably below 150μm. A particle distribution of the Fe- Si alloy powder prepared by the high-pressure water atomization is 5~150μm, and an average particle diameter is about 20μm. Moreover, if a Si content becomes below 3wt% in fabricating the Fe-Si alloy powder, the soft magnetic properties are degraded. If the Si content becomes over 10wt%, brittleness increases so that surface cracks frequently occur in molding. Hence, the Si content is preferably 3~10wt%.
In case of a binder used for giving insulating and cohesive properties between Fe-Si alloy powder particles, a softening point of the binder should be lower than an annealing temperature of the Fe-Si alloy powder for revealing high magnetic permeability and a sample, which has a predetermined cohesive strength at room temperature, is used to suppress crack generation while maintaining a shape of the core by a molding pressure on performing the pressurization molding at the room temperature. The binder is preferably selected from the group consisting of polyimide based ther o-hardening resin, phenol based thermo-hardening resin, and inorganic sodium silicate.
An amount of the binder is preferably limited to 0.2-3.0wt% of total mass. If the amount of the binder is below 0.2wt%, the cohesive strength is so weak that the surface cracks frequently occur in molding of the alloy powder. If the amount of the binder exceeds 3.0wt%, the cohesive strength between the alloy powder particles increases but the amount of the binder over the molding weight becomes excessive to degrade the soft magnetic properties. And, the total mass means totaled mass of the binder and alloy powder constructing the fabricated core.
In order to coat the Fe-Si alloy powder surface with the binder, the binder is dissolved in an organic solvent or water to prepare a binder solution. The Fe-Si alloy powder is then mixed with the binder solution so that the Fe-Si alloy powder surface is uniformly coated with the binder to the thickness below 0. Iμm for liquid phase coating 10.
Once the coating step 10 of the alloy powder is completed, the pressurization molding step 20 of pressurizing the coated alloy powder in a mold is executed to mold an SMD core. The molding pressure is preferably below 20 ton/cm2. If the molding pressure exceeds 20 ton/cm2, the increased abrasion and the frequent occurrence of surface scratches of the mold shorten a replacement period of the mold to increase the costs of production despite the enhancement of magnetic properties of the SMD core. On the other hand, if the molding pressure is smaller than 5 ton/cm2, molding density is lowered to degrade the magnetic properties.
The annealing step 30 of the molded core is performed to acquire the revelation of the excellent soft magnetic properties and the enhancement of the cohesive strength by removing the stresses generated from the preparation and molding of the powder to control the microstructure of the core. Annealing conditions are varied according to the usage of the core. Preferably, a material of high magnetic permeability (AL value: over 90nH/N2 at 100kHz) is annealed at 400-800 °C, whereas a material of low magnetic permeability (AL value: over 90nH/N2 at 100kHz) is not annealed. The magnetic permeability property is reduced below 400°C, and the binder is resolved over 800°C to degrade the insulating property between the powder particles. Annealing ambience is preferably provided by a non-oxidizing gas such as N2, Ar, and the like or a reducing gas such as H2, etc. And, annealing time is preferably set to 10-120 minutes. If the annealing time is too short, the stress fails to be sufficiently removed. If the annealing time is too long, productivity is reduced.
Preferred embodiments according to the present invention are explained as follows.
First Embodiment
First of all, a solution prepared by dissolving polyimide as a binder amounting to about 0.85wt% of total mass of Fe-Si alloy powder in methylene chloride is poured on Fe93.5Si6.5 (wt%) alloy powder (average particle diameter: 20μm, particle distribution: 5~150μm) prepared by water atomization to be mixed with each other. The mixed solution is then dried so that polyimide is uniformly coated on a surface of the Fe-Si alloy powder to the thickness below O.lμm to prepare powder of composite particles.
The polyimide-coated Fe-Si alloy powder is molded at a pressure of about 5 ton/cm2 in a mold, and is then annealed at 740 °C for about 60 minutes at an ambience of N2 or Ar gas to fabricate a Fe-Si alloy powder SMD core.
The SMD core generally includes a body and a cover. Hence, a body and a cover of the SMD core according to the present invention are fabricated using Fe-Si alloy powder by the above-explained method and are shown in Fig. 2 and Fig. 3, respectively. Fig. 2 shows development views and a perspective view of an SMD core body using Fe-Si alloy powder according to one embodiment of the present invention and Fig. 3 shows development views of an SMD core cover using Fe-Si alloy powder according to one embodiment of the present invention. A size of the fabricated SMD core is shown in the drawings. Shape and size of the SMD core fabricated by the method of fabricating the SMD core using Fe-Si alloy powder according to the present invention are not limited to the above-described embodiment of the present invention.
Average crystalline particle diameter, density, saturated magnetic flux density, and AL value coefficient ratio (ALlMHz/ALlkHz) in various frequency bands for the fabricated SMD core are shown in Table 1.
In the present invention, an average size of a powder particle diameter indicates a value of average particle diameters analyzed by Laser Particle Sizer and SEM (scanning electron microscope) , the density of the core is computed by dividing actual core weight by core volume, the saturated magnetic flux density (Bs) is measured under an external magnetic field of 5,000 Oe using VSM (vibrating sample magnetometer) , and the AL value is measured under an external magnetic field of 10 mOe at each frequency band using LCR meter. And, the AL value coefficient ratio (ALlMHz/ALlkHz) indicates a ratio between A values measured at 1MHz and 1kHz, respectively. Second Embodiment
A second embodiment according to the present invention is performed in the same manner of the first embodiment according to the present invention except that eg6.5Si3.5 (wt%) alloy powder (average particle diameter: 23μm, particle distribution: 5~150μm) prepared by water atomization is used as the Fe-Si alloy powder in the first embodiment of the present invention and that the amount of polyimide as the binder is changed into 0.5wt%. Third Embodiment A third embodiment according to the present invention is performed in the same manner of the first embodiment according to the present invention except that Fe9Sis(wt%) alloy powder (average particle diameter: 23μm, particle distribution: 5~150μm) prepared by water atomization is used as the Fe-Si alloy powder in the first embodiment of the present invention. Fourth Embodiment
A fourth embodiment according to the present invention is performed in the same manner of the first embodiment according to the present invention except that the amount of polyimide as the binder is changed into 1.2wt%.
Fifth Embodiment A fifth embodiment according to the present invention is performed in the same manner of the first embodiment according to the present invention except that the amount of sodium silicate used as the binder is 0.85wt%. Sixth Embodiment A sixth embodiment according to the present invention is performed in the same manner of the first embodiment according to the present invention except that the amount of phenol based resin used as the binder is 0.85wt%. Seventh Embodiment A seventh embodiment according to the present invention is performed in the same manner of the first embodiment according to the present invention except that annealing is not performed in molding the SMD core. Eighth Embodiment An eighth embodiment according to the present invention is performed in the same manner of the first embodiment according to the present invention except that the annealing temperature is set to 400°C. Ninth Embodiment
A ninth embodiment according to the present invention is performed in the same manner of the first embodiment according to the present invention except that the annealing temperature is set to 800 °C.
Tenth Embodiment
A tenth embodiment according to the present invention is performed in the same manner of the first embodiment according to the present invention except that the molding pressure is set to 12 ton/cm2.
First comparison Example
A first comparison example is performed in the same manner of the first embodiment according to the present invention except that Sendust (Fe84.1Si10.1 l5.8) alloy powder (average particle diameter: 28μm, particle distribution: 5~150μm) prepared by high-pressure water atomization is used as a conventional SMD core raw material for high magnetic permeability.
Second comparison Example A second comparison example is performed in the same manner of the first embodiment according to the present invention except that pure iron (Fe) powder (average particle diameter: 75μm, particle distribution: 10~150μm) is used as a conventional SMD core raw material for low magnetic permeability.
Meanwhile, properties of the SMD cores fabricated by the above-described embodiments according to the present invention and results from the comparison examples are summarized in Table 1.
Analysis results are explained by referring to Table 1 as follows.
First of all, in the overall embodiments of the present invention, the binder (polyimide, phenol, or sodium silicate) of high rigidity is mixed with Fe-Si based alloy powder containing 3.0~6.5wt% Si to prepare composite powder, and the composite powder is then molded at a pressure below 15 ton/cm2. In such a case, the molding density becomes at least 6.3, whereby the saturated magnetic flux density becomes at least 1.5T. And, the AL value at 100 kHz is at least 90 nH/N2 if annealing is skipped, whereas it becomes at least 100 nH/N2 if annealing is performed. Specifically, in case of the Fe-Si based alloy powder core containing 6.5wt% Si, when the molding is performed at 5 ton/cm2 and the annealing is performed at 740°C, the AL value at 100 kHz is at least 125 nH/N2 and the AL value coefficient ratio (AL MHZ/AL kHz) becomes at least 0.98. Such an AL value is superior to that of the commercialized SMD core product using Sendust alloy powder. And, the corresponding saturated magnetic flux density is 1.5 times higher than that of the commercialized SMD core product using Sendust alloy powder. [Table 1]
Figure imgf000018_0001
INDUSTRIAL APPLICABILITY
Accordingly, in an SMD core using Fe-Si alloy powder and fabrication method thereof according to the present invention, excellent magnetic properties of the SMD core appear in radio frequency band, the SMD core having excellent cohesive strength, saturated magnetic flux density, and effective magnetic permeability (or inductance) can be fabricated, and the SMD core having both of the excellent frequency characteristics and the soft magnetic properties can be mass-produced with low process or raw material costs by performing annealing within a range of low temperature between 400-800 °C in fabricating a material of high magnetic permeability (A value: over 110 nH/N2 at 100 kHz) .
While the present invention has been described and illustrated herein with reference to the preferred embodiments thereof, it will be apparent to those skilled in the art that various modifications and variations can be made therein without departing from the spirit and scope of the invention. Thus, it is intended that the present invention covers the modifications and variations of this invention that come within the scope of the appended claims and their equivalents.

Claims

WHAT IS CLAIMED IS:
1. A method of fabricating an SMD core using Fe-Si alloy powder, comprising: a step (a) of preparing a binder solution by dissolving a binder in an organic solvent or water; a step (b) of preparing a composite particle powder by coating the binder solution on a Fe-Si alloy powder surface; and a step (c) of molding the composite particle powder.
2. The method of claim 1, further comprising an annealing step of performing annealing on the composite particle powder at 400~800°C after the step (c) .
3. The method of claim 2, wherein the annealing in the step (c) is performed at a non-oxidizing or reducing gas ambience.
4. The method of claim 2 or claim 3, wherein an annealing time of the step (c) is 10-120 minutes.
5. The method of claim 1 or claim 2, wherein the binder in the step (a) is selected from the group consisting of polyimide based resin, phenol based resin, and sodium silicate and wherein a content of the binder is 0.2-3.0wt% of total mass of the binder and the Fe-Si alloy powder.
6. The method of claim 1 or claim 2, wherein a molding pressure in the step (c) is 5-20 ton/cm2 and a molding time is 5-30 seconds.
7. The method of claim 1 or claim 2, wherein a Si content of the Fe-Si alloy powder is 3~0wt%, a Fe content of the Fe-Si alloy powder is 90~97wt%, and a particle diameter of the Fe-Si alloy powder is 10~150μm.
8. A Fe-Si alloy powder core fabricated by a method according to one of claim 1 to claim 3.
PCT/KR2003/002430 2002-11-13 2003-11-13 Fe-Si ALLOY POWDER CORES AND FABRICATION PROCESS THEREOF WO2004043633A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU2003280872A AU2003280872A1 (en) 2002-11-13 2003-11-13 Fe-Si ALLOY POWDER CORES AND FABRICATION PROCESS THEREOF

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
KR10-2002-0070389 2002-11-13
KR1020020070389A KR20040042214A (en) 2002-11-13 2002-11-13 FABRICATION PROCESS OF SMD CORE USING Fe-Si ALLOY POWDER

Publications (1)

Publication Number Publication Date
WO2004043633A1 true WO2004043633A1 (en) 2004-05-27

Family

ID=32310854

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/KR2003/002430 WO2004043633A1 (en) 2002-11-13 2003-11-13 Fe-Si ALLOY POWDER CORES AND FABRICATION PROCESS THEREOF

Country Status (3)

Country Link
KR (1) KR20040042214A (en)
AU (1) AU2003280872A1 (en)
WO (1) WO2004043633A1 (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102436895A (en) * 2011-12-19 2012-05-02 浙江大学 A kind of preparation method of sendust magnetic powder core
CN102982990A (en) * 2012-03-05 2013-03-20 宁波市普盛磁电科技有限公司 Manufacturing method for ferrum-silicon-aluminum magnetic cores
CN102982989A (en) * 2012-03-05 2013-03-20 宁波市普盛磁电科技有限公司 Manufacturing method for ferrum-silicon-aluminum magnetic cores
CN103797550A (en) * 2011-09-07 2014-05-14 株式会社昌星 Elliptical unit block for preparing core using soft magnetic metal powder, and powdered magnetic core prepared using same
CN109494039A (en) * 2018-11-27 2019-03-19 北京航空航天大学 Preparation method of FeSi-based composite soft magnetic material

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101443530B1 (en) * 2013-05-31 2014-09-22 영남대학교 산학협력단 Method for manufacturing fe-si magnetic core including glass power

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63166901A (en) * 1986-12-26 1988-07-11 Fukuda Metal Foil & Powder Co Ltd Fe-si-a alloy powder
JPH02290002A (en) * 1989-01-18 1990-11-29 Nippon Steel Corp Fe-si based alloy dust core and its manufacture
KR20020064713A (en) * 2002-07-02 2002-08-09 휴먼일렉스(주) Fe-Si alloy powder cores and fabrication process thereof

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100262488B1 (en) * 1995-12-05 2000-08-01 이구택 Manufacturing method of sintered iron-silicon lead magnetic alloy
JP2000030924A (en) * 1998-07-10 2000-01-28 Daido Steel Co Ltd Soft magnetic alloy powder and dust core
KR100396045B1 (en) * 2000-01-28 2003-08-27 (주)창성 Silicon steel powder processing method for soft magnetic core material and soft magnetic core processing method using this powder
KR100344010B1 (en) * 2001-01-05 2002-07-22 휴먼일렉스(주) Amorphous metal alloy powder cores for high frequency range and method for making the same

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63166901A (en) * 1986-12-26 1988-07-11 Fukuda Metal Foil & Powder Co Ltd Fe-si-a alloy powder
JPH02290002A (en) * 1989-01-18 1990-11-29 Nippon Steel Corp Fe-si based alloy dust core and its manufacture
KR20020064713A (en) * 2002-07-02 2002-08-09 휴먼일렉스(주) Fe-Si alloy powder cores and fabrication process thereof

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103797550A (en) * 2011-09-07 2014-05-14 株式会社昌星 Elliptical unit block for preparing core using soft magnetic metal powder, and powdered magnetic core prepared using same
EP2755215A4 (en) * 2011-09-07 2015-09-09 Chang Sung Co Elliptical unit block for preparing core using soft magnetic metal powder, and powdered magnetic core prepared using same
CN102436895A (en) * 2011-12-19 2012-05-02 浙江大学 A kind of preparation method of sendust magnetic powder core
CN102982990A (en) * 2012-03-05 2013-03-20 宁波市普盛磁电科技有限公司 Manufacturing method for ferrum-silicon-aluminum magnetic cores
CN102982989A (en) * 2012-03-05 2013-03-20 宁波市普盛磁电科技有限公司 Manufacturing method for ferrum-silicon-aluminum magnetic cores
CN109494039A (en) * 2018-11-27 2019-03-19 北京航空航天大学 Preparation method of FeSi-based composite soft magnetic material
CN109494039B (en) * 2018-11-27 2020-09-01 北京航空航天大学 A kind of preparation method of FeSi-based soft magnetic composite soft magnetic material

Also Published As

Publication number Publication date
KR20040042214A (en) 2004-05-20
AU2003280872A1 (en) 2004-06-03

Similar Documents

Publication Publication Date Title
JP5412425B2 (en) Composite magnetic material and method for producing the same
JP5022999B2 (en) Powder magnetic core and manufacturing method thereof
WO2018179812A1 (en) Dust core
CN104190945B (en) The preparation method of a kind of amorphous metal soft magnetic-powder core
CN106158340B (en) A kind of Fe Si Al powder core toroidal magnets and preparation method thereof
KR20160093557A (en) Soft magnetic metal powder core
JP2010272604A (en) Soft magnetic powder and dust core using the same, and inductor and method of manufacturing the same
JP2003133122A (en) Dust core
CN107424711B (en) Iron-based composite powder for manufacturing magnetic powder core and die-pressed inductor and preparation method thereof
JP2015201481A (en) Powder-compact magnetic core arranged by use of nanocrystal soft magnetic alloy powder, and manufacturing method thereof
JP5063861B2 (en) Composite dust core and manufacturing method thereof
WO2004043633A1 (en) Fe-Si ALLOY POWDER CORES AND FABRICATION PROCESS THEREOF
JP2009147252A (en) Composite magnetic material and method for producing the same
CN104084586B (en) Filter-pressing preparation method for soft-magnetic composite material
JP2003068550A (en) Soft magnetism pot core, manufacturing method thereof, and reactor using the same
JP2005116820A (en) Dust core
JP2006100292A (en) Powder magnetic core manufacturing method and powder magnetic core using the same
CN116612975B (en) A method for preparing high-frequency low-loss iron-based soft magnetic composite material
JP2023169098A (en) Soft magnetic powder composition and manufacturing method of inductor core by use thereof
CN111599567B (en) Composite magnetic material, magnetic core, and electronic component
KR100344010B1 (en) Amorphous metal alloy powder cores for high frequency range and method for making the same
KR100499013B1 (en) Fe-Si alloy powder cores and fabrication process thereof
JP2004327762A (en) Composite soft magnetic material
JP6458853B1 (en) Powder magnetic core and inductor element
US20200168376A1 (en) Magnetic powder, compressed powder core, method of preparation thereof

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE EG ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NI NO NZ OM PG PH PL PT RO RU SC SD SE SG SK SL SY TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): BW GH GM KE LS MW MZ SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LU MC NL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
122 Ep: pct application non-entry in european phase
NENP Non-entry into the national phase

Ref country code: JP

WWW Wipo information: withdrawn in national office

Country of ref document: JP