WO2022033033A1 - 一种电磁波噪声抑制片材及高频电子设备 - Google Patents

一种电磁波噪声抑制片材及高频电子设备 Download PDF

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WO2022033033A1
WO2022033033A1 PCT/CN2021/082042 CN2021082042W WO2022033033A1 WO 2022033033 A1 WO2022033033 A1 WO 2022033033A1 CN 2021082042 W CN2021082042 W CN 2021082042W WO 2022033033 A1 WO2022033033 A1 WO 2022033033A1
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noise suppression
electromagnetic wave
wave noise
suppression sheet
sheet according
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PCT/CN2021/082042
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English (en)
French (fr)
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李绪亮
戚超勇
葛现金
满其奎
谭果果
李润伟
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宁波磁性材料应用技术创新中心有限公司
中国科学院宁波材料技术与工程研究所
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Priority to KR1020237008553A priority Critical patent/KR20230073189A/ko
Publication of WO2022033033A1 publication Critical patent/WO2022033033A1/zh

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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K9/00—Screening of apparatus or components against electric or magnetic fields
    • H05K9/0073—Shielding materials
    • H05K9/0081—Electromagnetic shielding materials, e.g. EMI, RFI shielding
    • H05K9/0083—Electromagnetic shielding materials, e.g. EMI, RFI shielding comprising electro-conductive non-fibrous particles embedded in an electrically insulating supporting structure, e.g. powder, flakes, whiskers
    • 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
    • H01F1/153—Amorphous metallic alloys, e.g. glassy metals
    • H01F1/15325—Amorphous metallic alloys, e.g. glassy metals containing rare earths
    • 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
    • H01F1/153—Amorphous metallic alloys, e.g. glassy metals
    • H01F1/15341—Preparation processes therefor

Definitions

  • the invention belongs to the technical field of electromagnetic compatibility, and in particular relates to an electromagnetic wave noise suppression sheet and high-frequency electronic equipment.
  • a near-field noise suppression sheet that converts excess radiated electromagnetic waves (noise) into heat is usually attached to equipment or the like.
  • the thickness of the noise suppression sheet is 0.02 mm to 2 mm, so it can be used by directly pasting or pasting in the vicinity of an electronic component or electronic circuit that is a noise source, and is easy to process and has a high degree of freedom in shape. . Therefore, the noise suppression sheet can be adapted to the miniaturization and weight reduction of electronic equipment and communication equipment which are advancing, and is widely used as a noise countermeasure member of electronic equipment or communication equipment.
  • the most commonly used electromagnetic noise suppression materials mainly include coating type and composite type.
  • the coating type material is made by mixing electromagnetic wave absorber and resin binder to make a coating, and then coating it on the surface of the protective body; composite type material It is an enhanced electromagnetic noise suppression material prepared by mixing electromagnetic wave absorbers with organic adhesives or multi-layer fibers.
  • the magnetic anisotropy of the soft magnetic alloy powder with respect to the in-plane anisotropy of the noise suppression sheet can be improved by processing the flat shape, and by utilizing the magnetic anisotropy, the magnetic permeability can be controlled according to the frequency of the electromagnetic wave to be absorbed.
  • the distribution of part ⁇ ” improves the absorption and suppression of electromagnetic waves at high frequency and improves the power loss ratio of electromagnetic waves.
  • the magnetic materials used in the current large-scale noise suppression sheet are mainly Fe-Si-Al, carbonyl iron, ferrite and other series of materials, as described in the patent documents CN103609207B, CN104072117A, CN107836140B, but the high performance of these magnetic materials
  • the frequency magnetic permeability is low, and the thickness of the noise suppression sheet is often thick, which limits its use in the GHz frequency band.
  • Patent document CN107377960B improves the imaginary part ⁇ " of magnetic permeability at high frequency by adjusting the formulation of FeMn alloy and the aspect ratio of flake powder.
  • Patent document CN107481829A uses Fe-Si-Al particle powder to control the particle size and The aspect ratio improves the mutual decoupling of the noise suppression sheet.
  • the noise suppression sheet described in the above patent documents has excellent noise suppression performance in the frequency band of 10MHz-5GHz, but in the frequency band of 5GHz and above, ⁇ ' and ⁇ " are relatively low, and the power loss is also difficult to meet the requirements of electronic equipment and electronic equipment in the 5G communication era. Requirements for electromagnetic noise suppression of high-frequency communication equipment.
  • the present invention uses soft magnetic RE a M b X c powder in electromagnetic wave noise suppression sheet, and finds that it has excellent noise suppression effect in high frequency band, and the real part of permeability is u in the range of 3-10 GHz. '>3, imaginary part u">3, power loss ratio Ploss/Pin>90%, transmission attenuation rate Rtp>20dB.
  • an electromagnetic wave noise suppression sheet comprising soft magnetic alloy powder, characterized in that: the chemical composition molecular formula of the soft magnetic alloy powder is RE a M b X c , wherein a, b, c is the number of atoms, where 0.5 ⁇ a ⁇ 20, 1 ⁇ b ⁇ 50, 0 ⁇ c ⁇ 10;
  • RE is one or more of rare earth elements La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Y;
  • M is one or more of Fe, Co, Ni, Mn, Cr, Ti, Cu, Zn, Al, Ga, Ag, Nb, Zr;
  • X is one or more of the elements N, B, Si, C, S, P, O.
  • RE is one or more of rare earth elements La, Ce, Pr, Nd, Sm, Dy, Ho, Yb, Y;
  • M is one or more of Fe, Co, Ni, Cr, Cu, Zn, and Al;
  • X is one or more of N, B, Si, and C.
  • the shape of the soft magnetic alloy powder is flat.
  • the thickness of the soft magnetic alloy powder is 10 nm-10 ⁇ m, the size of the flakes is 10-200 ⁇ m, and the aspect ratio is 5-500. More preferably, the thickness is 10 nm-2 ⁇ m, the size of the flakes is 10-100 ⁇ m, and the aspect ratio is 10-100.
  • the preparation method of the soft magnetic alloy powder comprises: preparing raw materials of corresponding purity according to the chemical composition and molecular formula of the soft magnetic alloy powder, mixing and then smelting, and pouring the molten alloy liquid to obtain an alloy ingot or an alloy flake, Then, it is crushed to obtain powder, and the particle size of the powder is preferably 1-100 ⁇ m; or, the molten alloy liquid is gas-atomized to obtain spherical powder, and the particle size of the powder is preferably 5-200 ⁇ m.
  • the flat soft magnetic alloy powder is obtained by subjecting the soft magnetic alloy powder to flake processing, and the flake processing includes at least one of bedroom sand milling, planetary ball milling, vertical stirring mill and other processes or It consists of a variety of methods.
  • the preferred mechanical methods such as bedroom sand mill and vertical stirring mill are grinding and shearing.
  • the flat soft magnetic alloy powder is subjected to passivation treatment to reduce the electrical conductivity of the soft magnetic alloy powder.
  • the passivation treatment includes chemical treatment and heat treatment under a specific atmosphere, wherein the purpose of the chemical treatment is to coat an insulating layer or a high resistance layer on the surface of the powder, such as SiO 2 , TiO 2 , Al 2 O 3 , ZnO 2
  • the thickness of the layer is preferably 1-100 nm;
  • the heat treatment is mainly for the heat treatment of the soft magnetic alloy powder containing interstitial atoms N and C, including nitriding or carburizing treatment.
  • the nitriding treatment method is heat treatment in high-pressure (>1MPa) high-purity nitrogen or ammonia gas.
  • Carburizing treatment is vacuum heat treatment in a furnace chamber containing graphite or carbon components.
  • the electromagnetic wave noise suppression sheet sequentially includes a resistance layer, a magnetic layer, a metal layer, and an insulating layer in the thickness direction; wherein the magnetic layer contains the soft magnetic alloy powder.
  • the resistance layer is a thin layer with high resistance, its surface resistance value is 10 4 -10 8 ⁇ / ⁇ , preferably 10 5 -10 8 ⁇ / ⁇ , and the average thickness is 10-200 ⁇ m.
  • the resistance layer is a mixed layer including ferrite and a binder.
  • Ferrites are mainly NiZn ferrites, Co 2 Z-type hexagonal ferrites, and the like.
  • the average particle size of the ferrite is 0.1-20 ⁇ m, and the mass fraction does not exceed 10%.
  • the magnetic layer is an absorption loss layer for electromagnetic waves.
  • the thickness of the magnetic layer is 0.05-2 mm, more preferably 0.1-1.0 mm.
  • the magnetic layer is a mixed layer including the soft magnetic alloy powder, a binder and an additive.
  • the additives include one or more of flame retardants, defoaming agents, plasticizers, and the like.
  • the content of the soft magnetic alloy powder is 50-98%
  • the content of the binder is 2-40%
  • the balance is additives.
  • the magnetic layer is obtained by mixing the soft magnetic alloy powder, the binder, and the additives, followed by casting and lamination, and the thickness is preferably 0.05-2 mm, more preferably 0.1-1.0 mm.
  • an electromagnetic field parallel to the plane of the magnetic layer is applied, preferably, the size of the electromagnetic field is 1-2T.
  • the adhesive includes, but is not limited to, rubber, resin, polyurethane, and the like.
  • the resin is selected from any resin-based materials such as epoxy resin, phenolic resin, cellulose resin, polyethylene resin, polyester resin, polyvinyl chloride resin, and polyacetal resin.
  • the rubber is selected from any rubber-based material such as silicone rubber, acrylic rubber, nitrile rubber, butyl rubber, polyvinyl alcohol resin, and chlorinated polyethylene resin.
  • the defoamer includes but is not limited to modified silicon polydimethylsiloxane, modified polyether silicon, special silicone-free defoamer composed of mineral oil, special polyether ester and dispersant, etc. .
  • the plasticizer includes, but is not limited to, dibutyl sebacate (DBS), di-n-butyl adipate (DBA), dibutyl phthalate (DBP), and the like.
  • the flame retardants include, but are not limited to, one or more of metal hydroxides, nitrogen-containing cyclic compounds, phosphorus compounds with amide bonds, and the like.
  • the metal hydroxides are Mg(OH) 2 and Al(OH) 3 , and the amide-bonded phosphorus compound contains at least ammonium polyphosphate and red phosphorus.
  • the metal layer mainly reflects the electromagnetic waves that are not completely lost and transmitted by the magnetic layer into the magnetic layer for further loss, and at the same time plays the role of heat conduction.
  • the metal layer structure is not limited, and may be a single-layer thin film structure or a multi-layer thin film structure composed of Fe, Ni, Al, Zn, Cu, Ag, and Ti.
  • the thickness of the metal layer is preferably 20 nm to 50 ⁇ m, more preferably 0.5 ⁇ m to 20 ⁇ m.
  • the preparation method of the metal layer is not limited, including any one of coating, magnetron sputtering, vacuum evaporation, and electrodeposition.
  • a metal layer is first prepared on a substrate.
  • the substrate material is not limited, including stainless steel, Al, Mg, Cu, etc., and then the metal layer is peeled off from the substrate and bonded to the magnetic layer or insulating layer; Metal layers are obtained directly on the magnetic or insulating layers using methods other than electrodeposition. According to the realization degree and stability of the process, magnetron sputtering and coating methods are preferred to prepare the metal layer.
  • the insulating layer is used to prevent interference from noise sources and conduction of surrounding electronic components.
  • the insulating layer is a resin with high resistivity and low dielectric constant.
  • the resins include, but are not limited to, polyimide, polyethylene terephthalate, liquid crystal polymers, and fluororesins.
  • one layer can be directly placed on the surface of the other layers by deposition and spraying, or it can be connected by bonding.
  • adhesives include cyanoacrylate adhesives, ethyl cellulose, acrylic resins, polyvinyl acetal resins, polyurethane, polyethylene glycol, epoxy resin adhesives and other well-known adhesives.
  • the magnetic permeability test under high-frequency electromagnetic wave is to use a vector network analyzer to make the test sample into a cylindrical ring with an outer diameter of 7.00mm and an inner diameter of 3.04mm, and use a coaxial double-ended wire fixture to test the frequency range of 0.1-18GH Internal electromagnetic parameters.
  • the power loss ratio and the transmission attenuation rate are calculated according to the IEC standard (IEC 62333-2), and a vector network analyzer is also used.
  • the measurement fixture is a microstrip line whose impedance is adjusted to 50 ⁇ . Cut the test sample to a length of 100mm and a width of 50mm, then evenly cover the microstrip line, connect the microstrip line to the vector network analyzer, measure the reflection parameter S11 and transmission parameter S21 of the microstrip line at 0.1-18GHz, and then according to The formula calculates P loss /P in and R tp .
  • a foamed polystyrene board with a thickness of 10mm and a foaming ratio of the same size as the sheet is 20-30 times. Overlapped with the test sample, a 300g load was placed thereon.
  • the four-probe method is used to detect the surface resistance, the size of the sample is larger than 50mm ⁇ 50mm, and the thickness is corrected for the measurement.
  • the flame retardant characterization method is as follows: vertically fix the test sample (length 125mm, width 13mm, record the thickness of the sample), place the burner at 10mm from the lower end of the sample, and remove the burner after maintaining for 10s. Ignite it again for 10s, remove the burning appliance and record the after-flame time t to check whether there is any inflammable material falling. The measurement of flame retardancy is classified according to the UL94 grade.
  • the present invention applies the RE a M b X c soft magnetic alloy powder to the electromagnetic noise suppression sheet, and obtains excellent noise suppression performance in the high frequency band of 3-10 GHz, and the real part and the imaginary part of the magnetic permeability are respectively More than 3, the power loss ratio Ploss/Pin>90%, the transmission attenuation rate Rtp>20dB, which solves the problem that the noise suppression sheet in the prior art has low ⁇ ' and ⁇ " in the frequency band above 5GHz, and the power loss is low Therefore, it is difficult to meet the electromagnetic noise suppression requirements of high-frequency electronic equipment such as the 5G communication era. It has a good application prospect in the electromagnetic noise suppression of electronic equipment, especially high-frequency electronic equipment (frequency in the GHz range).
  • FIG. 1 is a cross-sectional view of a high-frequency electromagnetic noise suppressing sheet in Examples 1-4 of the present invention.
  • FIG. 2 is a graph showing the variation of the real part of the magnetic permeability with frequency in Examples 1-4 of the present invention.
  • FIG. 3 is a graph showing the variation of the imaginary part of the magnetic permeability with frequency in Examples 1-4 of the present invention.
  • FIG. 4 is a graph showing the variation of the power loss ratio Ploss/Pin with frequency in Examples 1-4 of the present invention.
  • FIG. 5 is a curve showing the variation of the transmission attenuation rate Rtp with the frequency in Embodiments 1-4 of the present invention.
  • the reference numerals in FIG. 1 are: resistance layer 1 , magnetic layer 2 , soft magnetic alloy powder 3 , metal layer 4 , insulating layer 5 .
  • the composition of the selected soft magnetic material is Y 1.5 Nd 0.5 Co 8 Fe 5.5 Ni 3.0 Mn 0.5
  • the powder preparation method is as follows:
  • step 2) The alloy flakes obtained in step 1) are crushed to a particle size of 0.1-1 mm with a hammer crusher, and then the particle powder is further crushed to an average particle size of 15 ⁇ m using a jet mill.
  • step 2) The powder obtained in step 2) is further ground by ball milling process, the grinding medium is stainless steel balls of 3 mm and 5 mm, the mass ratio of the two is 3:1, the ratio of balls to material is 20:1, the grinding solvent is dehydrated alcohol, and the ball is milled. After 4 hours, a flat powder was obtained with an average size of 20 ⁇ m and an average thickness of 150 nm.
  • a SiO 2 film with an average thickness of 10 nm is formed on the flat powder obtained in step 3) by a sol-gel process.
  • the electromagnetic wave noise suppression sheet includes a resistance layer 1, a magnetic layer 2, a metal layer 4 and an insulating layer 5 in order in the thickness direction, wherein the magnetic layer 2 contains Y 1.5 Nd 0.5 obtained in the above step 4).
  • Co 8 Fe 5.5 Ni 3.0 Mn 0.5 soft magnetic alloy powder 3 the preparation method is as follows:
  • the Co 2 Z-type hexagonal ferrite with an average particle size of 500 nm was uniformly mixed into the epoxy resin, and the mass fraction of the ferrite was 5%. Then, the epoxy resin mixed with ferrite is coated on the upper surface of the magnetic layer, and cured at 80° C. for 12 hours to obtain a resistance layer. According to the method for testing surface resistance of the present invention, the surface resistance value is measured to be 7.6 ⁇ 10 6 ⁇ / ⁇ , the average thickness is 40 ⁇ m.
  • the above-mentioned magnetic layer adhered with the resistance layer was placed in a magnetron sputtering cavity, and a metal Zn layer with a thickness of 10 ⁇ m was sputtered on the lower surface of the magnetic layer.
  • a polyimide insulating layer with a thickness of 20 ⁇ m is bonded to the surface of the metal Zn layer, and finally a noise suppression sheet with a thickness of 0.44-0.48 mm is obtained.
  • the noise suppression sheet prepared above is prepared into a circular ring with an inner diameter of 3.04 mm and an outer diameter of 7.00 mm to test the magnetic permeability, and cut out a 100 mm ⁇ 50 mm sheet to test the power loss ratio and transmission attenuation rate.
  • the composition of the selected soft magnetic material is Y 0.85 Nd 0.65 Ho 0.2 Fe 10.8 Al 4.2 Cu 1.0 Si 2.0
  • the powder preparation method is as follows:
  • step 2) the powder obtained in step 1) is further processed with a vertical stirring mill, the grinding medium is stainless steel balls of 3mm and 5mm, the mass ratio of the two is 1:1, the ratio of ball to material is 20:1, and the grinding solvent is dehydrated alcohol, The ball milling time was 3h, and a flat powder was obtained with an average size of 40 ⁇ m and an average thickness of 200 nm.
  • step 3 Add the flat powder obtained in step 2) into the solution of cyclohexane, stir evenly to form a slurry, and apply ultrasonic dispersion at the same time, and then add 1.5% nano-Al 2 O 3 and nano-Al into the slurry.
  • the average particle size of 2 O 3 was 5 nm.
  • an Al 2 O 3 film with an average thickness of 10 nm was attached to the surface of the flake powder.
  • the electromagnetic wave noise suppression sheet includes a resistance layer 1, a magnetic layer 2, a metal layer 4 and an insulating layer 5 in order in the thickness direction, wherein the magnetic layer 2 contains Y 0.85 Nd 0.65 obtained in the above step 3).
  • Ho 0.2 Fe 10.8 Al 4.2 Cu 1.0 Si 2.0 soft magnetic alloy powder 3 the preparation method is as follows:
  • the NiZn ferrite with an average particle size of 500 nm is uniformly mixed into the polyurethane, and the mass fraction of NiZn ferrite is 6%. Then, the polyurethane sol mixed with ferrite is directly coated on the upper surface of the magnetic layer, and cured at 80° C. for 8 hours to obtain a resistance layer. According to the method for testing surface resistance of the present invention, the surface resistance value is measured to be 5.0 ⁇ 10 7 ⁇ / ⁇ , and the average thickness is 80 ⁇ m.
  • the above-mentioned magnetic layer adhered with the resistance layer was placed in a magnetron sputtering cavity, and a metal Ni layer with a thickness of 10 ⁇ m was sputtered on the lower surface of the magnetic layer.
  • a polyimide insulating layer with a thickness of 20 ⁇ m is bonded to the surface of the metal Ni layer, and finally a noise suppression sheet with a thickness of 0.6-0.62 mm is obtained.
  • the noise suppression sheet prepared above is prepared into a circular ring with an inner diameter of 3.04 mm and an outer diameter of 7.00 mm to test the magnetic permeability, and cut out a 100 mm ⁇ 50 mm sheet to test the power loss ratio and transmission attenuation rate.
  • the composition of the selected soft magnetic material is Ce 1.5 Y 0.3 La 0.2 Fe 15 Co 2 N 3.5
  • the preparation method of the powder is as follows:
  • step 2) The alloy flakes obtained in step 1) are crushed to a particle size of 0.1-2mm with a hammer crusher, then screened to 0.2-0.8mm with a cyclone, and finally a vibration ball mill is used to further crush the particle powder to an average particle size of 50 ⁇ m. .
  • step 2) The granular powder obtained in step 2) is further ground by using a bedroom sand mill, the grinding medium is 3mm zirconia balls, the ball-to-material ratio is 20:1, the grinding solvent is anhydrous ethanol, and the ball milling time is 4h to obtain flat powder , with an average size of 50 ⁇ m and an average thickness of 700 nm.
  • step 4) Put the flat powder obtained in step 3) into the vacuum heat treatment, first pump the vacuum to 10 -3 Pa, fill with Ar gas of 0.01MPa, then fill with high-purity nitrogen of 5MPa, and heat to 450 After being kept at °C for 2 hours, then rapidly cooled to room temperature to obtain Ce 1.5 Y 0.3 La 0.2 Fe 15 Co 2 N 3.5 flake powder.
  • the electromagnetic wave noise suppression sheet includes a resistance layer 1, a magnetic layer 2, a metal layer 4 and an insulating layer 5 in order in the thickness direction, wherein the magnetic layer 2 contains the Ce 1.5 Y 0.3 obtained in the above step 4).
  • La 0.2 Fe 15 Co 2 N 3.5 soft magnetic alloy powder 3 the preparation method is as follows:
  • the NiZn ferrite with an average particle size of 2 ⁇ m was uniformly mixed into the epoxy resin, and the mass fraction of the ferrite was 5%. Then, the epoxy resin was directly coated on the upper surface of the magnetic layer, and the resistance layer was obtained by curing at 80° C. for 12 hours. According to the method for testing the surface resistance of the present invention, the surface resistance value was measured to be 8 ⁇ 10 7 ⁇ / ⁇ , and the average value was 8 ⁇ 10 7 ⁇ / ⁇ . Thickness 35 ⁇ m.
  • a layer of Fe film with an average thickness of 10 ⁇ m is adhered to the lower surface of the magnetic layer with the resistance layer adhered, and the adhesive is a cyanoacrylate adhesive.
  • a fluororesin insulating layer with an average thickness of 40 ⁇ m was bonded to the surface of the Fe film, and finally a noise suppression sheet with a thickness of 0.27-0.30 mm was obtained.
  • the noise suppression sheet prepared above is prepared into a circular ring with an inner diameter of 3.04 mm and an outer diameter of 7.00 mm to test the magnetic permeability, and cut out a 100 mm ⁇ 50 mm sheet to test the power loss ratio and transmission attenuation rate.
  • the composition of the selected soft magnetic material is Sm 1.85 Ce 0.2 Fe 12 Ti 1.0 Ga 0.5 B 1.2
  • the powder preparation method is as follows:
  • step 2) The alloy flakes obtained in step 1) are crushed to a particle size of 0.1-1 mm with a hammer crusher, and then the particle powder is further crushed to an average particle size of 30 ⁇ m using an air flow mill.
  • step 2) further grinding the powder obtained in step 2) by using a bedroom sand mill, the grinding medium is a 4mm stainless steel ball, the ratio of the ball to the material is 20:1, the grinding solvent is anhydrous ethanol, and the ball milling time is 6h to obtain a flat powder, Its average size is 50 ⁇ m and its average thickness is 300 nm.
  • a SiO 2 film with an average thickness of 10 nm is formed on the flat powder obtained in step 3) by a sol-gel method.
  • the electromagnetic wave noise suppression sheet includes a resistance layer 1, a magnetic layer 2, a metal layer 4 and an insulating layer 5 in order in the thickness direction, wherein the magnetic layer 2 contains the Sm 1.85 Ce 0.2 obtained in the above step 4).
  • Fe 12 Ti 1.0 Ga 0.5 B 1.2 soft magnetic alloy powder 3 the preparation method is as follows:
  • Co 2 Z-type hexagonal ferrite with an average particle size of 3 ⁇ m was uniformly mixed into the butyl rubber, and the mass fraction of the ferrite was 4%. Then, the butyl rubber mixed with ferrite is directly coated on the upper surface of the magnetic layer, and cured at 120° C. for 10 hours to obtain a resistance layer. According to the method for testing surface resistance of the present invention, the surface resistance value is measured to be 4.5 ⁇ 10 6 ⁇ / ⁇ , and the average thickness is 50 ⁇ m.
  • a layer of Cu film with an average thickness of 20 ⁇ m was pasted on the lower surface of the magnetic layer with the resistance layer adhered, and the adhesive was a cyanoacrylate adhesive.
  • a polyethylene terephthalate insulating layer with an average thickness of 50 ⁇ m is bonded on the surface of the Cu film, and an acrylic resin adhesive is used for bonding, and finally a noise suppression sheet with a thickness of 0.9-0.94 mm is obtained.
  • the noise suppression sheet prepared above is prepared into a circular ring with an inner diameter of 3.04 mm and an outer diameter of 7.00 mm to test the magnetic permeability, and cut out a 100 mm ⁇ 50 mm sheet to test the power loss ratio and transmission attenuation rate.
  • Fig. 2 The change curve of the magnetic permeability real part of the noise suppression sheet prepared in the above-mentioned Examples 1-4 with frequency is shown in Fig. 2, which shows that the magnetic permeability real part u'>4.5 in the range of 3-7 GHz, and in the range of 7-7 GHz The real part of permeability u'>3 in the range of 10GHz.
  • the power loss ratio Ploss/Pin of the noise suppression sheets prepared in the above examples 1-4 is shown in Fig. 4 as a function of frequency, showing that the power loss ratio Ploss/Pin>90% in the range of 3-10 GHz.
  • the curve of the transmission attenuation rate Rtp of the noise suppression sheet prepared in the above examples 1-4 is shown in Figure 5, which shows that the transmission attenuation rate Rtp>20dB in the range of 3-10GHz, and the transmission attenuation rate in the range of 4-10GHz Attenuation rate Rtp>30dB.

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Abstract

本发明提供一种电磁波噪声抑制片材及高频电子设备。该电磁波噪声抑制片材包括REaMbXc软磁性合金粉末，其中a、b、c是原子个数，0.5<a<20、1<b<50、0≤c<10；在3-10GHz高频段具有优异的噪声抑制性能，其磁导率实部和虚部分别大于3，功率损耗比Ploss/Pin＞90％，传输衰减率Rtp＞20dB，在5G通讯时代电子设备，尤其是高频电子设备的电磁噪声抑制方面具有良好的应用前景。

Description

一种电磁波噪声抑制片材及高频电子设备 技术领域
本发明属于电磁兼容技术领域，具体涉及一种电磁波噪声抑制片材及高频电子设备。
背景技术
随着电子器件、通讯技术、微波技术的快速发展，特别是5G通讯技术的快速发展，产品和器件内应用频率的提高，电子设备或通信设备的小型化、轻量化，装配于电子电路的部件的安装密度也升高。从电子部件放射的电磁波噪声为起因，在电子部件彼此间或电子电路彼此间产生电磁波干涉而引起的电子设备或通信设备的误动作成为问题。电子设备高频化和集成化的快速发展，***的电磁噪声干扰问题日益突出。
为了解决上述问题，通常是在设备等上安装将多余的放射电磁波(噪声)转换成热量的近场用噪声抑制片。该噪声抑制片的厚度为0.02mm～2mm，因此可以通过直接粘贴于作为噪声产生源的电子部件或电子电路、或者粘贴于电子部件或电子电路的附近来使用，易于加工且形状自由度也高。所以，噪声抑制片能够适应于不断发展的电子设备或通信设备的小型化、轻量化，广泛地使用作为电子设备或通信设备的噪声应对部件。
目前最常用的电磁噪声抑制材料主要包括涂覆型和复合型两种，其中涂覆型材料是将电磁波吸收剂与树脂粘合剂混合制成涂料，然后涂覆在防护体表面；复合型材料则是将电磁波吸收剂混合在有机粘接剂或者多层纤维中制备而成的增强型电磁噪声抑制材料。
噪声抑制片的特性依赖于所包含软磁性合金粉末的磁导率，以及磁粉的自燃共振频率。通常磁导率μ＝μ’-j*μ”，但是在噪声抑制片利用磁损失的情形下，虚部磁导率μ”显得更为重要。虚部越高，对电磁波的功率损耗越显著，而且μ”的极大值出现在自燃共振频率处。
通过加工扁平状能够提高相对于噪声抑制片的面内各向异性的软磁合金粉末的磁各向异性，通过利用该磁各向异性，能够根据要吸收的电磁波的频率来控制磁导率虚部μ”的分布，提高在高频段下对电磁波的吸收抑制，提高电磁波的功率损耗比。
当前规模应用的噪声抑制片中使用磁损耗的磁性材料主要为Fe-Si-Al、羰基铁、铁氧体等系列材料，如专利文献CN103609207B、CN104072117A、CN107836140B中所记载，但是这些磁性材料的高频磁导率低，噪声抑制片材厚度往往较厚，限制其在GHz频段下的使用。专利文献CN107377960B通过调整 FeMn合金的配方及片粉的长径比，提高了高频下磁导率的虚部μ”。专利文献CN107481829A使用Fe-Si-Al颗粒粉，控制粉体的粒径及长径比，改善噪声抑制片的相互去耦合性。
以上专利文献中记载的噪声抑制片材在10MHz-5GHz的频段有优异的噪声抑制性能，但是在5GHz及频段以上频段，μ’和μ”偏低，功率损耗也难以满足5G通讯时代电子设备和高频通讯设备的电磁噪声抑制的要求。
发明内容
针对上述技术现状，本发明将软磁RE aM bX c粉末用于电磁波噪声抑制片中，发现其在高频段下具有优异的噪声抑制效果，在3-10GHz范围内磁导率实部u’＞3、虚部u”＞3，功率损耗比Ploss/Pin＞90％、传输衰减率Rtp＞20dB。
即，本发明的技术方案为：一种电磁波噪声抑制片材，包括软磁性合金粉末，其特征是：所述软磁性合金粉末的化学组成分子式为RE aM bX c，其中a、b、c是原子个数，其中0.5<a<20、1<b<50、0≤c<10；
RE是稀土元素La、Ce、Pr、Nd、Sm、Eu、Gd、Tb、Dy、Ho、Er、Tm、Yb、Lu、Y中一种或多种；
M是Fe、Co、Ni、Mn、Cr、Ti、Cu、Zn、Al、Ga、Ag、Nb、Zr中一种或多种；
X是元素N、B、Si、C、S、P、O中一种或多种。
作为优选，1<a<10。
作为优选，2<b<40。
作为优选，0≤c<5。
作为优选，RE是稀土元素La、Ce、Pr、Nd、Sm、Dy、Ho、Yb、Y中一种或多种；
作为优选，M是Fe、Co、Ni、Cr、Cu、Zn、Al中一种或多种；
作为优选，X是N、B、Si、C中一种或多种。
作为优选，所述软磁性合金粉末的形状呈扁平状。作为进一步优选，所述软磁性合金粉末的厚度为10nm-10μm、片粉面尺寸为10-200μm、长径比为5-500。作为更优选，其厚度为10nm-2μm、片粉面尺寸为10-100μm、长径比为10-100。
作为优选，所述软磁性合金粉末的制备方法包括：根据软磁性合金粉末的化学组成分子式准备相应纯度的原材料，混合后进行熔炼，将熔融的合金液进行浇注，得到合金铸锭或合金薄片，然后进行破碎，得到粉体，粉体粒径优选为1-100μm；或者，将熔融的合金液通过气雾化得到球形粉体，粉体粒径优选为5-200μm。
作为优选，所述扁平状软磁性合金粉末是通过将软磁性合金粉末进行片状化处理得到，所述片状化处理包括卧室砂磨、行星球磨、立式搅拌磨等工艺中至少 一种或多种方法组成，根据工艺实现的难易程度，优选卧室砂磨、立式搅拌磨等磨削、剪切为主的机械方式。
作为进一步优选，将所述扁平状软磁性合金粉末进行钝化处理，用于降低所述软磁性合金粉末的导电性。所述钝化处理包括化学处理和特定气氛下的热处理，其中化学处理的目的是在粉体表面包覆一层绝缘层或者高电阻层，如SiO 2、TiO 2、Al 2O 3、ZnO 2层，其厚度优选1-100nm；热处理主要是针对含有间隙原子N、C的软磁合金粉末的热处理，包括渗氮或渗碳处理。渗氮处理方法是在高压(＞1MPa)高纯氮气或者氨气中进行热处理。渗碳处理是在石墨或者碳素成分的炉室进行真空热处理。
作为一种实现方式，所述电磁波噪声抑制片在厚度方向依次包含电阻层、磁性层、金属层、绝缘层；其中磁性层中含有所述软磁性合金粉末。
作为优选，所述电阻层是呈高电阻的的薄层，其表面电阻值为10 4-10 8Ω/□，优选为10 5-10 8Ω/□，平均厚度为10-200μm。
作为一种实现方式，所述电阻层是包括铁氧体与粘结剂的混合层。铁氧体主要为NiZn铁氧体、Co 2Z型六角铁氧体等。作为优选，铁氧体的颗粒平均尺寸在0.1-20μm，质量份数不超过10％。
所述磁性层是电磁波的吸收损耗层。作为优选，所述磁性层厚度为0.05-2mm，更优选为0.1-1.0mm。作为一种实现方式，所述磁性层是包括所述软磁性合金粉末、粘接剂与添加剂的混合层。添加剂包括阻燃剂、消泡剂、增塑剂等中的一种或者几种。作为优选，所述磁性层中，按照质量百分含量计，所述软磁性合金粉末的含量为50-98％，粘接剂的含量为2-40％，余量为添加剂。作为优选，所述磁性层是将所述软磁性合金粉末、粘接剂与添加剂等混合后流延、叠压而获得，厚度优选为0.05-2mm，更优选为0.1-1.0mm。所述流延过程中施加平行于磁性层平面方向的电磁场，作为优选，电磁场大小1-2T。
所述粘接剂包括但不限于橡胶、树脂、聚氨酯等。树脂选自环氧树脂、酚醛树脂、纤维素树脂、聚乙烯树脂、聚酯树脂、聚氯乙烯树脂、聚缩醛树脂等任意的树脂系材料。橡胶选自硅橡胶、丙烯酸橡胶、丁腈橡胶、丁基橡胶、聚乙烯醇树脂、氯化聚乙烯树脂等任意的橡胶系材料。
所述消泡剂包括但不限于改性硅聚二甲基硅氧烷、改性聚醚硅，由矿物油、特种聚醚酯和分散剂等组成的不含有机硅的特殊消泡剂等。
所述增塑剂包括但不限于癸二酸二丁酯(DBS)、已二酸二正丁酯(DBA)、邻苯二甲酸二丁酯(DBP)等。
所述阻燃剂包括但不限于金属氢氧化物、含氮环状化合物、具有酰胺结合的磷类化合物等一种或多种。其中金属氢氧化物为Mg(OH) 2、Al(OH) 3，酰胺结合的磷类化合物至少含有聚磷酸铵和红磷。
所述金属层主要是将磁性层未完全损耗透射的电磁波完全反射到磁性层中 进一步损耗，同时起到导热的作用。金属层结构不限，可以是Fe、Ni、Al、Zn、Cu、Ag、Ti构成的单层薄膜结构或多层薄膜结构。金属层厚度优选为20nm-50μm，更优选为0.5μm-20μm。
所述金属层的制备方法不限，包括涂覆、磁控溅射、真空蒸镀、电沉积中任一种方法。作为一种实现方式，首先在基板制备金属层，所述基板材料不限，包括不锈钢、Al、Mg、Cu等，然后将金属层从基板上剥离，粘接到磁性层或者绝缘层；也可以直接在磁性层或绝缘层上利用除电沉积之外的其他方法获得金属层。根据工艺实现程度和稳定性，优选磁控溅射、涂覆方法制备金属层。
所述绝缘层用于阻止噪声源和周边电子部件导电的干扰。作为优选，所述绝缘层是具有高电阻率、低介电常数的树脂。所述树脂包括但不限于聚酰亚胺、聚对苯二甲酸乙二醇酯、液晶聚合物和氟树脂。
所述各层之间在可行条件下可通过沉积、喷涂直接将一层置于其它层表面，也可以可通过粘接相连。常用的粘接胶包括氰基丙烯酸酯粘结剂、乙基纤维素、丙烯酸类树脂、聚乙烯醇缩醛树脂、聚氨酯、聚乙二醇、环氧树脂胶等公知粘接胶。
本发明中，高频电磁波下磁导率测试是使用矢量网络分析仪，将测试样品制成外径7.00mm、内径3.04mm的圆筒环，利用同轴双端线夹具，测试0.1-18GH频率范围内电磁参数。
本发明中，功率损耗比和传输衰减率的计算是按照IEC标准(IEC 62333-2)，同样是使用矢量网络分析仪，测量夹具是阻抗调节为50Ω的微带线。将测试样品裁剪至长100mm，宽50mm，然后均匀覆盖在微带线上方，将微带线与矢量网络分析仪连接，测定微带线在0.1-18GHz的反射参数S11和透射参数S21，然后根据公式算出P loss/P in和R tp。为保证微带线的长度方向与片材分长度方向及各自的中心一致的方式进行安装，将与片材同尺寸的发泡倍率为20-30倍的厚度在10mm的发泡聚苯乙烯板与测试样品重叠，在其上放置300g载荷。
Figure PCTCN2021082042-appb-000001
Figure PCTCN2021082042-appb-000002
本发明中，采用四探针法检测表面电阻，样品尺寸大于50mm×50mm，测量进行厚度修正。
本发明中，阻燃的表征方法为：将试验样品(长125mm，宽13mm，记录样品厚度)垂直固定，将燃具置于样品下端10mm处，维持10s后移开燃具，余焰熄灭时再次点燃10s，移开燃具后记录余焰时间t，检查是否有可燃物掉落，阻燃性的测量按照UL94等级进行划分。
与现有技术相比，本发明将RE aM bX c软磁合金粉末应用于电磁噪声抑制片 材，在3-10GHz高频段得到优异的噪声抑制性能，磁导率实部和虚部分别大于3，功率损耗比Ploss/Pin＞90％，传输衰减率Rtp＞20dB，解决了现有技术中的噪声抑制片材在5GHz及频段以上频段，μ’和μ”偏低，功率损耗较低，因此难以满足5G通讯时代等高频电子设备的电磁噪声抑制要求的问题，在电子设备，尤其是高频电子设备(频率在GHz范围)的电磁噪声抑制方面具有良好的应用前景。
附图说明
图1是本发明实施例1-4中高频电磁噪声抑制片的剖视图。
图2是本发明实施例1-4磁导率实部随频率变化曲线。
图3是本发明实施例1-4磁导率虚部随频率变化曲线。
图4是本发明实施例1-4功率损耗比Ploss/Pin随频率变化曲线。
图5是本发明实施例1-4传输衰减率Rtp随频率变化曲线。
图1中的附图标记为：电阻层1、磁性层2、软磁性合金粉体3、金属层4、绝缘层5。
具体实施方式
下面结合实施例与附图对本实用新型进一步详细描述，需要指出的是，以下所述实施例旨在便于对本发明的理解，而对其不起任何限定作用。
实施例1：
本实施例中，选定的软磁材料的成分是Y 1.5Nd 0.5Co 8Fe 5.5Ni 3.0Mn 0.5，其粉体的制备方法如下：
1)使用纯度≥99.9％的Y、Nd和纯度≥99.95％的Co、Fe、Ni、Mn，首先去除各金属的表层氧化层，按配比分别称重，其中稀土Y和Nd过量5％。将各金属加入真空熔炼炉中进行电磁感应熔炼，熔炼温度控制在1400-1450℃，保温5分钟。然后将熔融的合金液浇注到转速为1.5m/s的旋转铜辊上，最终得到厚度0.1-0.3mm的合金薄片。
2)将步骤1)得到的合金薄片用锤式破碎机破碎至颗粒度0.1-1mm，然后使用气流磨将颗粒粉进一步破碎到平均粒径为15μm。
3)利用球磨工艺将步骤2)得到的粉体进一步研磨加工，研磨介质是3mm和5mm的不锈钢球，二者质量比3:1，球料比20:1，研磨溶剂是无水乙醇，球磨时间4h，获得扁平状粉体，其平均尺寸为20μm，平均厚度为150nm。
4)利用溶胶凝胶工艺在步骤3)得到的扁平状粉体上生成平均厚度为10nm的SiO 2膜。
将上述步骤4)制得的Y 1.5Nd 0.5Co 8Fe 5.5Ni 3.0Mn 0.5粉体应用于电磁波噪声抑制片材。如图1所示，该电磁波噪声抑制片材在厚度方向依次包含电阻层1、磁性层2、金属层4与绝缘层5，其中磁性层2中含有上述步骤4)制得的 Y 1.5Nd 0.5Co 8Fe 5.5Ni 3.0Mn 0.5软磁性合金粉体3，制备方法如下：
称取上述步骤4)制得的Y 1.5Nd 0.5Co 8Fe 5.5Ni 3.0Mn 0.5粉体80g，与20g粘结剂、0.2ml消泡剂、1g增塑剂和8g阻燃剂混合，搅拌均匀，直至磁粉已经完全被粘接剂包裹，获得适当粘度的浆料。本实施例中使用的粘接剂、消泡剂、增塑剂和阻燃剂分别是聚乙烯树脂、二甲基硅氧烷、DBS和Mg(OH) 2粉。
将搅拌均匀的浆料倒入流延机入口，开启流延开关，浆料经刮刀均匀铺在PET膜上，调整流延膜厚度为0.1mm，与此同时在平行薄膜方向施加1.0T的磁场，最后加热至60℃烘干。待流延膜干燥后，从PET基底上取下，裁剪至长宽为100mm×100mm；通过热压机在0.3Mpa、100℃下热压60min，获得厚度为0.4mm的磁性层。
将平均粒径500nm的Co 2Z型六角铁氧体均匀混入环氧树脂中，铁氧体的质量分数为5％。然后将混合铁氧体的环氧树脂涂覆到磁性层的上表面，在80℃下固化12h获得电阻层，按照本发明的测试表面电阻的方法测得其表面电阻值为7.6×10 6Ω/□，平均厚度为40μm。
将上述粘有电阻层的磁性层放置在磁控溅射的腔体内，在磁性层的下表面溅射一层厚度10μm的金属Zn层。
使用环氧树脂胶，在金属Zn层表面粘接厚度20μm的聚酰亚胺绝缘层，最终获得厚度在0.44-0.48mm的噪声抑制片材。
将上述制得的噪声抑制片材制备成内径为3.04mm、外径为7.00mm的圆环测试磁导率，剪裁出100mm×50mm的片材测试功率损耗比和传输衰减率，按照本发明中表征阻燃的方法进行阻燃表征。
实施例2：
本实施例中，选定的软磁材料的成分是Y 0.85Nd 0.65Ho 0.2Fe 10.8Al 4.2Cu 1.0Si 2.0，其粉体的制备方法如下：
1)使用纯度≥99.9％的Y、Nd、HoFe(钬铁，Ho质量占比30％)和纯度≥99.95％的Fe、Al、Cu、Si，首先去除各金属的表层氧化层，按配比分别称重，其中稀土Y和Nd过量10％。将各金属加入雾化设备的熔炼炉中进行高温熔炼，温度控制在1300-1350℃，保温5分钟。然后将熔融的合金引流至喷嘴，用2MPa的Ar气喷射形成球形液滴，经冷却、分级后获得平均粒径80μm的近球形粉体。
2)将步骤1)得到的粉体用立式搅拌磨进一步加工，研磨介质是3mm和5mm的不锈钢球，二者质量比1:1，球料比20:1，研磨溶剂是无水乙醇，球磨时间3h，获得扁平状粉体，其平均尺寸为40μm，平均厚度为200nm。
3)将步骤2)得到的扁平状粉体加入环己烷的溶液中，搅拌均匀形成浆料，同时施加超声波分散，然后在浆料中加入质量分数1.5％的纳米Al 2O 3，纳米Al 2O 3的平均粒径为5nm，搅拌和超声分散2h后，片状粉体表面附着一层平均厚度10nm的Al 2O 3膜。
将上述步骤3)制得的Y 0.85Nd 0.65Ho 0.2Fe 10.8Al 4.2Cu 1.0Si 2.0粉体应用于电磁波噪声抑制片材。如图1所示，该电磁波噪声抑制片材在厚度方向依次包含电阻层1、磁性层2、金属层4与绝缘层5，其中磁性层2中含有上述步骤3)制得的Y 0.85Nd 0.65Ho 0.2Fe 10.8Al 4.2Cu 1.0Si 2.0软磁性合金粉体3，制备方法如下：
称取上述步骤3)制得的Y 0.85Nd 0.65Ho 0.2Fe 10.8Al 4.2Cu 1.0Si 2.0粉体85g，与15g粘结剂、0.15ml消泡剂、2g增塑剂和6g阻燃剂混合，搅拌均匀，直至磁粉已经完全被粘接剂包裹，获得适当粘度的浆料。本实施例中使用的粘接剂、消泡剂、增塑剂和阻燃剂分别是聚氨酯、改性聚醚硅、DBS和Al(OH) 3粉。
将搅拌均匀的浆料倒入流延机入口，开启流延开关，浆料经刮刀均匀铺在PET膜上，调整流延膜厚度为0.1mm，与此同时在平行薄膜方向施加1.0T的磁场，最后加热至60℃烘干。待流延膜干燥后，从PET基底上取下，裁剪至长宽为100mm×100mm；通过热压机在0.35Mpa、120℃下热压60min获得厚度为0.5mm的磁性层。
将平均粒径500nm的NiZn铁氧体均匀混入聚氨酯中，NiZn铁氧体的质量分数6％。然后直接将混有铁氧体的聚氨酯溶胶涂覆到磁性层的上表面，在80℃下固化8h获得电阻层，按照本发明的测试表面电阻的方法测得其表面电阻值为5.0×10 7Ω/□，平均厚度为80μm。
将上述粘有电阻层的磁性层放置在磁控溅射的腔体内，在磁性层的下表面溅射一层厚度10μm的金属Ni层。
使用环氧树脂胶，在金属Ni层的表面粘接厚度20μm的聚酰亚胺绝缘层，最终获得厚度在0.6-0.62mm的噪声抑制片材。
将上述制得的噪声抑制片材制备成内径为3.04mm、外径为7.00mm的圆环测试磁导率，剪裁出100mm×50mm的片材测试功率损耗比和传输衰减率，按照本发明中表征阻燃的方法进行阻燃表征。
实施例3：
本实施例中，选定的软磁材料的成分是Ce 1.5Y 0.3La 0.2Fe 15Co 2N 3.5，其粉体的制备方法如下：
1)使用纯度≥99.9％的Y、Nd、La和纯度≥99.95％的Co、Fe，首先去除各金属的表层氧化层，按配比分别称重，其中稀土Ce和Y过量10％。将各金属加入真空熔炼炉中进行电磁感应熔炼，熔炼温度控制在1400-1450℃，保温5分钟。然后将熔融的合金液浇注到转速为1.5m/s的旋转铜辊上，最终得到厚度0.1-0.3mm的合金薄片。
2)将步骤1)得到的合金薄片用锤式破碎机破碎至颗粒度0.1-2mm，然后用旋风分离筛选至0.2-0.8mm，最后使用震动球磨，将颗粒粉进一步破碎到平均粒径为50μm。
3)利用卧室砂磨机将步骤2)得到的颗粒粉进一步研磨加工，研磨介质是 3mm氧化锆球，球料比20:1，研磨溶剂是无水乙醇，球磨时间4h，获得扁平状粉体，其平均尺寸为50μm，平均厚度为700nm。
4)将步骤3)得到的扁平状粉体放入真空热处理内，先将真空抽到10 -3Pa后，充入0.01MPa的Ar气，然后再充入5MPa的高纯氮气，加热至450℃后保温2h，然后快速冷却到室温，获得Ce 1.5Y 0.3La 0.2Fe 15Co 2N 3.5片粉。
将上述步骤4)制得的Ce 1.5Y 0.3La 0.2Fe 15Co 2N 3.5片粉应用于电磁波噪声抑制片材。如图1所示，该电磁波噪声抑制片材在厚度方向依次包含电阻层1、磁性层2、金属层4与绝缘层5，其中磁性层2中含有上述步骤4)制得的Ce 1.5Y 0.3La 0.2Fe 15Co 2N 3.5软磁性合金粉体3，制备方法如下：
称取上述步骤4)制得的Ce 1.5Y 0.3La 0.2Fe 15Co 2N 3.5片粉80g，与20g粘结剂、0.2ml消泡剂、2g增塑剂和8g阻燃剂混合，搅拌均匀，直至磁粉已经完全被粘接剂包裹，获得适当粘度的浆料。本实施例中使用的粘接剂、消泡剂、增塑剂和阻燃剂分别是硅橡胶、特种聚醚酯、已二酸二正丁酯、酰胺结合的磷类化合物。
将搅拌均匀的浆料倒入流延机入口，开启流延开关，浆料经刮刀均匀铺在PET膜上，调整流延膜厚度为0.1mm，与此同时在平行薄膜方向施加1.0T的磁场，最后在加热至60℃烘干。待流延膜干燥后，从PET基底上取下，裁剪至长宽为100mm×100mm；通过热压机在0.4Mpa、60℃下热压100min，获得厚度为0.2mm的磁性层。
将平均粒径2μm的NiZn铁氧体均匀混入环氧树脂中，铁氧体的质量分数为5％。然后直接将环氧树脂涂覆到磁性层的上表面，在80℃下固化12h获得电阻层，按照本发明的测试表面电阻的方法测得其表面电阻值为8×10 7Ω/□，平均厚度35μm。
将上述粘有电阻层的磁性层的下表面粘结一层平均厚度10μm的Fe膜，粘接胶是氰基丙烯酸酯粘结剂。
使用氰基丙烯酸酯粘结剂，在Fe膜的表面粘接平均厚度40μm的氟树脂绝缘层，最终获得厚度在0.27-0.30mm的噪声抑制片材。
将上述制得的噪声抑制片材制备成内径为3.04mm、外径为7.00mm的圆环测试磁导率，剪裁出100mm×50mm的片材测试功率损耗比和传输衰减率，按照本发明中表征阻燃的方法进行阻燃表征。
实施例4：
本实施例中，选定的软磁材料的成分是Sm 1.85Ce 0.2Fe 12Ti 1.0Ga 0.5B 1.2，其粉体的制备方法如下：
1)使用纯度≥99.9％的Sm、Ce和纯度≥99.95％的Fe、Ti、Ga、BFe(硼铁，其中B含量25％)，首先去除各金属的表层氧化层，按配比分别称重，其中稀土Sm过量15％。然后将各金属加入真空熔炼炉中进行电磁感应熔炼，熔炼温度控制在1350-1400℃，保温5分钟。然后将熔融的合金液浇注到转速为1.0m/s的旋 转铜辊上，最终得到厚度0.2-0.4mm的合金薄片。
2)将步骤1)得到的合金薄片用锤式破碎机破碎至颗粒度0.1-1mm，然后使用气流磨将颗粒粉进一步破碎到平均粒径为30μm。
3)利用卧室砂磨机将步骤2)得到的粉体进一步研磨加工，研磨介质是4mm不锈钢球，球料比20:1，研磨溶剂是无水乙醇，球磨时间6h，获得扁平状粉体，其平均尺寸为50μm，平均厚度为300nm。
4)利用溶胶凝胶法在步骤3)得到的扁平状粉体上生成一层平均厚度10nm的SiO 2膜。
将上述步骤4)制得的Sm 1.85Ce 0.2Fe 12Ti 1.0Ga 0.5B 1.2粉体应用于电磁波噪声抑制片材。如图1所示，该电磁波噪声抑制片材在厚度方向依次包含电阻层1、磁性层2、金属层4与绝缘层5，其中磁性层2中含有上述步骤4)制得的Sm 1.85Ce 0.2Fe 12Ti 1.0Ga 0.5B 1.2软磁性合金粉体3，制备方法如下：
称取上述步骤4)制得的Sm 1.85Ce 0.2Fe 12Ti 1.0Ga 0.5B 1.2粉体90g，与10g粘结剂、0.2ml消泡剂、2g增塑剂和10g阻燃剂混合，搅拌均匀，直至磁粉已经完全被粘接剂包裹，获得适当粘度的浆料。本实施例中使用的粘接剂、消泡剂、增塑剂和阻燃剂分别是酚醛树脂、改性聚醚硅、邻苯二甲酸二丁酯、含氮环状化合物。
将平均粒径3μm的Co 2Z型六角铁氧体均匀混入丁基橡胶中，铁氧体的质量分数为4％。然后直接将混有铁氧体丁基橡胶涂覆到磁性层的上表面，在120℃下固化10h获得电阻层，按照本发明的测试表面电阻的方法测得其表面电阻值为4.5×10 6Ω/□，平均厚度为50μm。
将上述粘有电阻层的磁性层的下表面粘贴一层平均厚度20μm的Cu膜，粘接胶是氰基丙烯酸酯粘结剂。
在Cu膜的表面粘接平均厚度为50μm的聚对苯二甲酸乙二醇酯绝缘层，使用丙烯酸类树脂粘结胶粘接，最终获得厚度在0.9-0.94mm的噪声抑制片材。
将上述制得的噪声抑制片材制备成内径为3.04mm、外径为7.00mm的圆环测试磁导率，剪裁出100mm×50mm的片材测试功率损耗比和传输衰减率，按照本发明中表征阻燃的方法进行阻燃表征。
上述实施例1-4中制得的噪声抑制片材的磁导率实部随频率变化曲线如图2所示，显示在3-7GHz范围内磁导率实部u’＞4.5、在7-10GHz范围内磁导率实部u’＞3。
上述实施例1-4中制得的噪声抑制片材的磁导率虚部随频率变化曲线如图3所示，显示在3-10GHz范围内磁导率虚部u”＞3.5、在4-10GHz范围内磁导率虚部u”＞4，在7-10GHz范围内磁导率虚部u”＞4.5。
上述实施例1-4中制得的噪声抑制片材的功率损耗比Ploss/Pin随频率变化曲线如图4所示，显示在3-10GHz范围内功率损耗比Ploss/Pin＞90％。
上述实施例1-4中制得的噪声抑制片材的传输衰减率Rtp随频率变化曲线如 图5所示，显示在3-10GHz范围内传输衰减率Rtp＞20dB，在4-10GHz范围内传输衰减率Rtp＞30dB。
上述实施例1-4中制得的噪声抑制片材结构与部分测试结果如下表所示：
Figure PCTCN2021082042-appb-000003
以上所述的实施例对本发明的技术方案进行了详细说明，应理解的是以上所述仅为本发明的具体实施例，并不用于限制本发明，凡在本发明的原则范围内所做的任何修改、补充或类似方式替代等，均应包含在本发明的保护范围之内。

Claims (33)

  1. 一种电磁波噪声抑制片材，包括软磁性合金粉末，其特征是：所述软磁性合金粉末的化学组成分子式为RE aM bX c，其中a、b、c是原子个数，其中0.5<a<20、1<b<50、0≤c<10；
    RE是稀土La、Ce、Pr、Nd、Sm、Eu、Gd、Tb、Dy、Ho、Er、Tm、Yb、Lu、Y中一种或多种；
    M是Fe、Co、Ni、Mn、Cr、Ti、Cu、Zn、Al、Ga、Ag、Nb、Zr中一种或多种；
    X是元素N、B、Si、C、S、P、O中一种或多种。
  2. 如权利要求1所述的电磁波噪声抑制片材，其特征是：1<a<10。
  3. 如权利要求1所述的电磁波噪声抑制片材，其特征是：2<b<40。
  4. 如权利要求1所述的电磁波噪声抑制片材，其特征是：0≤c<5。
  5. 如权利要求1所述的电磁波噪声抑制片材，其特征是：RE是稀土La、Ce、Pr、Nd、Sm、Dy、Ho、Yb、Y中一种或多种。
  6. 如权利要求1所述的电磁波噪声抑制片材，其特征是：M是Fe、Co、Ni、Cr、Cu、Zn、Al中一种或多种。
  7. 如权利要求1所述的电磁波噪声抑制片材，其特征是：X是N、B、Si、C中一种或多种。
  8. 如权利要求1所述的电磁波噪声抑制片材，其特征是：所述软磁性合金粉末呈扁平状。
  9. 如权利要求8所述的电磁波噪声抑制片材，其特征是：所述软磁性合金粉末厚度为10nm-10μm、面尺寸为10-200μm、长径比为5-500。
  10. 如权利要求9所述的电磁波噪声抑制片材，其特征是：所述软磁性合金粉末厚度为10nm-2μm、面尺寸为10-100μm、长径比为10-100。
  11. 如权利要求1所述的电磁波噪声抑制片材，其特征是：所述软磁性合金粉末的制备方法包括：根据软磁性合金粉末的化学组成分子式准备相应纯度的原材料，混合后进行熔炼，将熔融的合金液进行浇注，得到合金铸锭或合金薄片，然后进行破碎，得到粉体；或者，将熔融的合金液通过气雾化得到球形粉体。
  12. 如权利要求11所述的电磁波噪声抑制片材，其特征是：得到合金铸锭或合金薄片，然后进行破碎，得到粉体的粒径为1-100μm；将熔融的合金液通过气雾化得到球形粉体的粒径为5-200μm。
  13. 如权利要求8所述的电磁波噪声抑制片材，其特征是：所述扁平状软磁性合金粉末是通过将软磁性合金粉末进行片状化处理得到；
    所述片状化处理包括卧室砂磨、行星球磨、立式搅拌磨等工艺中至少一种或多种方法组成。
  14. 如权利要求8所述的电磁波噪声抑制片材，其特征是：将所述扁平状软 磁性合金粉末进行钝化处理；
    所述钝化处理包括化学处理和特定气氛下的热处理；
    所述化学处理是在粉体表面包覆一层绝缘层或者高电阻层；
    所述热处理包括渗氮或渗碳处理。
  15. 如权利要求14所述的电磁波噪声抑制片材，其特征是：绝缘层或者高电阻层的厚度为1-100nm。
  16. 如权利要求1所述的电磁波噪声抑制片材，其特征是：所述电磁波噪声抑制片在厚度方向依次包含电阻层、磁性层、金属层、绝缘层；其中磁性层中含有所述软磁性合金粉末。
  17. 如权利要求16所述的电磁波噪声抑制片材，其特征是：所述电阻层的平均厚度为10-200μm，表面电阻值为10 4-10 8Ω/□，优选为10 5-10 8Ω/□。
  18. 如权利要求16所述的电磁波噪声抑制片材，其特征是：所述电阻层是包括铁氧体与粘结剂的混合层。
  19. 如权利要求18所述的电磁波噪声抑制片材，其特征是：铁氧体的颗粒平均尺寸在0.1-20μm，质量份数不超过10％。
  20. 如权利要求16所述的电磁波噪声抑制片材，其特征是：所述磁性层厚度为0.05-2mm。
  21. 如权利要求16所述的电磁波噪声抑制片材，其特征是：所述磁性层是包括所述软磁性合金粉末、粘接剂与添加剂的混合层；
    添加剂包括阻燃剂、消泡剂、增塑剂中的一种或者几种。
  22. 如权利要求21所述的电磁波噪声抑制片材，其特征是：所述磁性层中，按照质量百分含量计，所述软磁性合金粉末的含量为50-98％，粘接剂的含量为2-40％，余量为添加剂。
  23. 如权利要求21所述的电磁波噪声抑制片材，其特征是：所述磁性层是将所述软磁性合金粉末、粘接剂与添加剂混合后流延、叠压而获得。
  24. 如权利要求21所述的电磁波噪声抑制片材，其特征是：所述粘接剂包括橡胶、树脂、聚氨酯。
  25. 如权利要求24所述的电磁波噪声抑制片材，其特征是：树脂选自环氧树脂、酚醛树脂、纤维素树脂、聚乙烯树脂、聚酯树脂、聚氯乙烯树脂、聚缩醛树脂。
  26. 如权利要求24所述的电磁波噪声抑制片材，其特征是：橡胶选自硅橡胶、丙烯酸橡胶、丁腈橡胶、丁基橡胶、聚乙烯醇树脂、氯化聚乙烯树脂。
  27. 如权利要求23所述的电磁波噪声抑制片材，其特征是：流延过程中施加平行于磁性层平面方向的电磁场。
  28. 如权利要求27所述的电磁波噪声抑制片材，其特征是：电磁场大小为1-2T。
  29. 如权利要求16所述的电磁波噪声抑制片材，其特征是：所述金属层是Fe、Ni、Al、Zn、Cu、Ag、Ti构成的单层薄膜结构或多层薄膜结构。
  30. 如权利要求29所述的电磁波噪声抑制片材，其特征是：金属层厚度为20nm-50μm。
  31. 如权利要求30所述的电磁波噪声抑制片材，其特征是：金属层厚度为0.5μm-20μm。
  32. 如权利要求1至31中任一权利要求所述的电磁波噪声抑制片材，其特征是：在3-10GHz高频段，其磁导率实部和虚部分别大于3，功率损耗比Ploss/Pin＞90％，传输衰减率Rtp＞20dB。
  33. 一种高频电子设备，包括如权利要求1至31中任一权利要求所述的电磁波噪声抑制片材。
PCT/CN2021/082042 2020-08-12 2021-03-22 一种电磁波噪声抑制片材及高频电子设备 WO2022033033A1 (zh)

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