WO2022247465A1 - 磁性薄膜及其制备方法、半导体封装模组和电子设备 - Google Patents

磁性薄膜及其制备方法、半导体封装模组和电子设备 Download PDF

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WO2022247465A1
WO2022247465A1 PCT/CN2022/085002 CN2022085002W WO2022247465A1 WO 2022247465 A1 WO2022247465 A1 WO 2022247465A1 CN 2022085002 W CN2022085002 W CN 2022085002W WO 2022247465 A1 WO2022247465 A1 WO 2022247465A1
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layer
magnetic
thin film
sputtering
thickness
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PCT/CN2022/085002
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English (en)
French (fr)
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喻志刚
周俭军
狄伟
刘刚
李维
刘星
官建国
吴天龙
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华为技术有限公司
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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
    • H05K9/0084—Electromagnetic shielding materials, e.g. EMI, RFI shielding comprising a single continuous metallic layer on an electrically insulating supporting structure, e.g. metal foil, film, plating coating, electro-deposition, vapour-deposition
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
    • C23C14/06—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the coating material
    • C23C14/10—Glass or silica
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
    • C23C14/06—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the coating material
    • C23C14/14—Metallic material, boron or silicon
    • C23C14/20—Metallic material, boron or silicon on organic substrates
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
    • C23C14/06—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the coating material
    • C23C14/14—Metallic material, boron or silicon
    • C23C14/20—Metallic material, boron or silicon on organic substrates
    • C23C14/205—Metallic material, boron or silicon on organic substrates by cathodic sputtering
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
    • C23C14/22—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the process of coating
    • C23C14/34—Sputtering
    • C23C14/35—Sputtering by application of a magnetic field, e.g. magnetron sputtering
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
    • C23C14/22—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the process of coating
    • C23C14/54—Controlling or regulating the coating process
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F10/00—Thin magnetic films, e.g. of one-domain structure
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L23/00—Details of semiconductor or other solid state devices
    • H01L23/552—Protection against radiation, e.g. light or electromagnetic waves
    • 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
    • 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
    • H05K9/0086—Electromagnetic shielding materials, e.g. EMI, RFI shielding comprising a single discontinuous metallic layer on an electrically insulating supporting structure, e.g. metal grid, perforated metal foil, film, aggregated flakes, sintering

Definitions

  • the application relates to a magnetic thin film and a preparation method thereof, as well as a semiconductor packaging module and electronic equipment using the magnetic thin film.
  • Electromagnetic interference between devices and between electronic devices and the external environment has also increased dramatically.
  • Methods to solve electromagnetic interference problems are usually divided into two types: shielding and absorption.
  • shielding and absorption Relatively speaking, using absorbing materials to absorb excess electromagnetic waves can avoid secondary pollution, and it is more convenient and flexible to use, so it is a preferred solution.
  • the high integration of electronic equipment, very limited physical space and complex electromagnetic environment place extremely high requirements on the thickness and absorbing performance of the absorbing material.
  • the first aspect of the embodiment of the present application provides a magnetic thin film, including:
  • a composite layer located on one side of the substrate includes a plurality of stacked magnetic layers and a plurality of insulating dielectric layers, and the plurality of magnetic layers and the plurality of dielectric layers are alternately arranged on the side of the substrate cloth;
  • each magnetic layer is 2nm-100nm; the thickness of each dielectric layer is 2nm-10nm; the thickness of the composite layer is 50nm-10 ⁇ m; the composite layer includes multiple cracks, and the multiple cracks are aperiodic distribution, at least some of the plurality of cracks have different extending directions along the cross-section perpendicular to the stacking direction of the composite layer, and at least some of the multiple cracks extend non-linearly along the cross-section perpendicular to the stacking direction of the composite layer.
  • Adjacent magnetic layers are separated by a nanometer-thick dielectric layer, which can maintain the nanometer size effect and high proportion of interface atoms of the single-layer magnetic thin-layer material to the greatest extent, and maintain the magnetic properties caused by the shape of the nanometer-thick magnetic layer. Anisotropic, so it can still have the characteristics of high magnetic permeability.
  • the plurality of cracks is the release of internal stress in the plurality of magnetic layers and the plurality of dielectric layers during the sputtering process of forming the plurality of magnetic layers and the plurality of dielectric layers lead to.
  • the crack divides the composite layer into several regions.
  • the area of each of the regions along the cross-sectional direction is 0.001 mm 2 -0.3 mm 2 .
  • the cracks divide the continuous composite layer into several tiny regions, thereby significantly increasing the overall resistivity of the magnetic thin film. For example, if no cracks are formed in the magnetic thin film, the resistivity is about 0.01 ⁇ m, but in the present application, the resistivity of the entire magnetic thin film with the cracks is 0.2 ⁇ m-20000 ⁇ m.
  • the plurality of cracks at least include at least one of the following: along the stacking direction of each layer of the composite layer, cracks extending to a depth equal to the stacking height of the composite layer; In the stacking direction of the layers, the cracks extend to a depth less than the stacking height of the composite layers.
  • cracks are due to the accumulation of internal stress of the multi-layer film of the composite layer to a certain extent, the substrate is softened to a certain extent under the action of sputtering heat, and the cracks are caused by stress release; due to the different degrees of stress release, cracks may penetrate Composite layers, which may or may not penetrate the composite layer, can significantly increase the resistivity of the multilayer film.
  • the opening width of each crack is less than 2 ⁇ m.
  • the opening width of the crack is usually small, generally less than 2 microns; cracks with too large width are likely to cause tearing of the substrate, or significantly affect the magnetic properties.
  • the thickness of each magnetic layer is 5nm-40nm.
  • An overly thick magnetic layer will cause the growth of columnar crystals, resulting in excessively large grains and increased coercive force; it will also cause a demagnetization field to be formed inside the magnetic layer; a thicker magnetic layer will also cause the layer to be divided into multiple magnetic layers.
  • the domain and the domain wall will pin the magnetization vector movement, reduce the magnetic permeability, and lead to the deterioration of high-frequency characteristics, thereby significantly reducing the magnetic permeability.
  • the magnetic properties of the product obtained with too small magnetic layer thickness become poor, because a continuous magnetic thin film layer has not been formed when the sputtering thickness is small; it may also be because the proportion of the magnetic layer in the total thickness is too low, resulting in low saturation magnetization , so that a multilayer film with high magnetic permeability cannot be obtained.
  • the material of each magnetic layer is ferromagnetic metal or ferromagnetic alloy.
  • Ferromagnetic metals or ferromagnetic alloys generally have high saturation magnetization and low coercive force, and it is easier to obtain high magnetic permeability than other materials.
  • the composition of the dielectric layer is at least one of insulating oxide, nitride and fluoride.
  • a transition layer is formed between each adjacent magnetic layer and the medium layer, and the thickness of the transition layer is less than or equal to 10 nm; the transition layer contains the magnetic material in the magnetic layer and the medium layer Insulation material.
  • the transition layer acts as a buffer transition between the magnetic layer and the medium layer, thereby improving the bonding strength between the magnetic layer and the medium layer.
  • the volume ratio of the magnetic material in the transition layer is between 20% and 80%.
  • the total number of layers of the plurality of magnetic layers and the plurality of dielectric layers is greater than 50, and the total thickness is greater than 300 nm.
  • the total thickness of the plurality of magnetic layers and the plurality of dielectric layers is too small, on the one hand, it is not enough to produce sufficient absorption performance, that is, the product of the imaginary part of the magnetic permeability and the thickness is not high enough; The accumulated stress of the thin film is not enough to make the film crack.
  • Experimental data shows that thin film materials need at least 300nm to produce obvious cracks, and cracks can be produced more stably when the thickness is more than 1 micron.
  • the total thickness of the plurality of magnetic layers and the plurality of dielectric layers is 1 ⁇ m-10 ⁇ m.
  • the total thickness of the plurality of magnetic layers and the plurality of dielectric layers is not more than 10 microns at most, otherwise the accumulation of internal stress is too large, which will easily reduce the adhesion of the film layer and peel off. On the other hand, the excessive thickness takes too long, The commercial value is low.
  • the substrate is flexible, has a thickness of 5 ⁇ m-50 ⁇ m, a glass transition temperature of 25° C.-100° C., and a melting point greater than 100° C.
  • the material of the substrate is polyethylene terephthalate, polymethyl methacrylate, polybutadiene-styrene, polyphenylene sulfide, acrylonitrile-butadiene-benzene
  • vinyl plastics polyethylene terephthalate-1,4-cyclohexanedimethanol, and polystyrene.
  • the substrate has an influence on the generation of cracks. If the substrate is strong in rigidity, it is not conducive to the generation of cracks, and will cause the film layer to break and fall off when a certain film thickness is reached. In the process of sputtering to form the multiple magnetic layers and the multiple dielectric layers, a certain amount of heat will be generated and cause the temperature to rise, usually the temperature does not exceed 100°C, so it is required to use a glass transition temperature of 25°C-100°C, a melting point Flexible polymers above 100°C are used as film-forming substrates.
  • the substrate is a plastic encapsulation material layer with a thickness of 5 ⁇ m-500 ⁇ m.
  • the plurality of magnetic layers and the plurality of dielectric layers can be deposited on the plastic packaging material layer used to package electronic components, such as chips, etc., to effectively absorb internal crosstalk noises packaged by the plastic packaging material layer.
  • the second aspect of the embodiment of the present application provides a semiconductor packaging module, including electronic components, the above-mentioned magnetic film attached to the electronic components, and a metal shielding layer attached to the magnetic film; the The base layer of the magnetic film is a plastic sealing material layer.
  • the magnetic film absorbs the noise of crosstalk inside the semiconductor packaging module, and the metal shielding layer is used to prevent electromagnetic waves in the semiconductor packaging module from radiating to the outside, which can be effectively solved by the magnetic film and the metal shielding layer. Noise interference of semiconductor packaging modules.
  • the third aspect of the embodiment of the present application provides an electronic device, including a circuit board and the semiconductor package module described in the second aspect located on the circuit board.
  • a fourth aspect of the embodiments of the present application provides an electronic device, including the semiconductor package module described in the second aspect in which the casing is located in the casing.
  • the fifth aspect of the embodiment of the present application provides an electronic device, including a noise source that radiates electromagnetic waves and the magnetic thin film described in the first aspect, the magnetic thin film is attached to the noise source or arranged on the noise propagation path of the noise source .
  • the magnetic thin film is a wave-absorbing material with high magnetic permeability in the radio frequency microwave band, and can be arranged at the position where the electronic equipment needs to absorb electromagnetic waves to absorb redundant electromagnetic waves.
  • the electronic device includes a metal middle frame and metal parts, and the middle frame and the metal parts cooperate to form a cavity, and the noise source is arranged in the cavity, and the outside of the cavity A signal transmitter is provided, and the magnetic film is located in the cavity.
  • the interference noise generated by the noise source usually propagates outward along the cavity between the middle frame and the metal part, so a magnetic thin film is set in the cavity, and when the electromagnetic wave generated by the noise source passes through the magnetic thin film, it will be magnetically
  • the thin film absorbs and is difficult to transmit out of the cavity, thereby avoiding interference signals affecting the signal transmitter.
  • the sixth aspect of the embodiment of the present application provides a method for preparing a magnetic thin film, including:
  • a composite layer is formed on one side of the substrate, the composite layer includes a plurality of magnetic layers and a plurality of dielectric layers, and the plurality of magnetic layers and the plurality of dielectric layers are formed on one side of the substrate.
  • the sides are arranged alternately;
  • each magnetic layer is 2nm-100nm; the thickness of each dielectric layer is 2nm-10nm; the thickness of the composite layer is 50nm-10 ⁇ m;
  • the release of internal stress in the composite layer leads to the formation of non-periodically distributed multiple cracks in the composite layer, at least part of the multiple cracks are along the vertical direction of the composite layer.
  • the extension directions of the cross-sections in the stacking direction are different, and at least some of the plurality of cracks extend non-linearly along the cross-section perpendicular to the stacking direction of the composite layer.
  • the preparation method of the magnetic thin film of the present application has the advantages of convenience and low cost, and can adjust the magnetic permeability, magnetic resonance frequency and resistivity.
  • DC sputtering is adopted for each magnetic layer, the sputtering pressure is set to 0.1Pa-10.0Pa, the sputtering rate is 0.1nm/s-2nm/s, and the sputtering time of each layer is 5s-100s.
  • radio frequency sputtering is used for each dielectric layer, the sputtering pressure is set to 0.1Pa-10.0Pa, the sputtering rate is 0.05nm/s-0.1nm/s, and the sputtering time of each layer is 5s-500s.
  • the sputtering material In order to make the film accumulate enough internal stress to produce cracks during the sputtering process, the sputtering material should be sputtered at a higher sputtering rate; the lower the sputtering efficiency, the better the film quality and the inner Insufficient stress accumulation is difficult to produce cracks; if the sputtering efficiency is too high, the multilayer structure is easy to be damaged, or even powdered and peeled off; in addition, in the process of magnetron sputtering, the sputtering pressure is very important for the sputtering rate and film quality. If the sputtering pressure is too low, the target is difficult to glow or the glow is unstable, and the sputtering effect is not good; Magnetic properties are affected.
  • the preparation method further includes forming a transition layer between each adjacent magnetic layer and the dielectric layer, the transition layer contains the magnetic material in the magnetic layer and the insulating material in the dielectric layer , the thickness of the transition layer is less than or equal to 10 nm.
  • the transition layer is co-sputtered by DC and RF
  • the sputtering pressure is set at 0.1Pa-10.0Pa
  • the sputtering rate ratio between DC and RF sputtering is adjusted between 0.2-5
  • the sputtering time of each layer is less than or equal to 50s.
  • FIG. 1 is a schematic cross-sectional view of a magnetic thin film according to a first embodiment of the present application.
  • FIG. 2 is a schematic cross-sectional view of a magnetic thin film according to a second embodiment of the present application.
  • FIG. 3A and FIG. 3B are an exploded schematic view and a schematic cross-sectional view of an electronic device according to an embodiment of the present application.
  • FIG. 4 is a schematic cross-sectional view of a semiconductor packaging module according to an embodiment of the present application.
  • Fig. 5 is a flowchart of a method for preparing a magnetic thin film according to an embodiment of the present application.
  • FIG. 6 is a scanning electron microscope cross-sectional view of the magnetic thin film of Example 1.
  • FIG. 7 is an absorptivity curve of the magnetic thin film of Example 1.
  • FIG. 8 is a magnetic permeability spectrum of the magnetic thin film of Example 2.
  • FIG. 9 is a magnetic permeability spectrum of the magnetic thin film of Example 3.
  • Fig. 10 is the static magnetostatic performance curve of the magnetic thin film of Example 5.
  • FIG. 11 is an X-ray diffraction pattern of the magnetic thin film of Example 6.
  • FIG. 12 is a transmission microscope photograph of the magnetic thin film of Example 7.
  • FIG. 12 is a transmission microscope photograph of the magnetic thin film of Example 7.
  • FIG. 13 is a microscope reflection photograph of the magnetic thin film of Example 8.
  • the magnetic absorbent In a wave-absorbing material, the magnetic absorbent is filled into the polymer matrix to form a composite material, so that it has both the high magnetic permeability and high magnetic loss of the magnetic material and the flexibility and ease of processing of the polymer composite material. And get high insulation.
  • Magnetic absorbers generally choose magnetic micropowder with high magnetic permeability. According to the different frequency of absorbing materials, there are usually ferrite ( ⁇ 100MHz), soft magnetic alloy (100MHz-3GHz), carbonyl iron powder (3-18GHz) Several basic types. In wireless communication terminals, soft magnetic alloy powders are commonly used as magnetic absorbers, including FeNi alloys, FeSiAl alloys, FeSi alloys, and the like.
  • the magnetic absorber In order to improve the magnetic permeability, the magnetic absorber will be processed into flake micropowder, and it will be oriented and filled as much as possible. Because the shape anisotropy of the magnetic absorber makes it break through the limitation of the Snoek limit and obtain higher high-frequency magnetic permeability; and their orientation arrangement can enhance the magnetic permeability enhancement effect brought by the anisotropy; as high as possible Filling can increase the content of magnetic substances, increase the saturation magnetization of the material and correspondingly increase the magnetic permeability. In order to obtain high resistivity under high filling conditions, the surface of the magnetic absorber is usually insulated so that it can achieve an excellent insulating effect.
  • this kind of absorbing material can reach the maximum real part of the magnetic permeability of 250 and the imaginary part value of about 20 at 10MHz; the peak value of the imaginary part of the magnetic permeability is between 10-100MHz, which can reach about 60-80; As the frequency increases, the magnetic permeability decreases rapidly, and only reaches the real part value of about 5-10 at 1GHz, and the imaginary part value of about 10 to 20. Therefore, at high frequencies above 1 GHz, the magnetic permeability of the absorbing material is usually very limited.
  • Embodiments of the present application provide a magnetic thin film, which is a wave-absorbing material with high magnetic permeability in radio frequency and microwave frequency bands.
  • the magnetic thin film still has high magnetic permeability and high resistivity under the condition that the thickness reaches micron level.
  • the magnetic thin film 100 includes a substrate 10 and a composite layer on one side of the substrate 10 .
  • the composite layer includes a plurality of magnetic layers 20 and a plurality of dielectric layers 30 laminated on a surface of the substrate 10 .
  • the Z-axis shown in FIG. 1 represents the lamination direction of each layer of the composite layer
  • the Y-axis represents the direction perpendicular to the paper
  • the X-axis and Y-axis together define the cross-sectional direction of the magnetic thin film 100 .
  • the plurality of magnetic layers 20 and the plurality of dielectric layers 30 are arranged alternately.
  • the total thickness of the plurality of magnetic layers 20 and the plurality of dielectric layers 30 is 50 nm-10 ⁇ m, that is, the thickness of the composite layer is 50 nm-10 ⁇ m.
  • the data ranges involved in this application all include end values unless otherwise specified.
  • the closest to the substrate 10 in the magnetic thin film 100 is a dielectric layer 30 , but it is not limited thereto, and may also be a magnetic layer 20 .
  • the magnetic layer 20 is farthest from the substrate 10 in the magnetic thin film 100 , but it is not limited thereto.
  • the dielectric layer 30 is farthest from the substrate 10 .
  • the composite layer on the base 10 is formed with a pattern of irregular multiple cracks 31, and the multiple cracks 31 can be clearly seen under a microscope.
  • the multiple cracks 31 can be clearly seen under a microscope.
  • the random light-colored stripes in FIG. 12 and the random dark-colored stripes in FIG. 13 are all cracks 31 .
  • the micrographs in Fig. 12 and Fig. 13 are photographs in the cross-sectional direction perpendicular to the stacking direction of the composite layer, that is, the surface direction defined by the X-axis and the Y-axis. It can be seen that the randomness of the plurality of cracks 31 means that the plurality of cracks 31 are distributed aperiodically. At least some of the multiple cracks 31 have different extension directions perpendicular to the cross section, and at least some of the multiple cracks 31 extend non-linearly along the cross section.
  • the crack 31 is formed during the process of sputtering forming the composite layer, and the release of internal stress in the composite layer leads to cracking of the film.
  • the preparation of the magnetic thin film 100 adopts the magnetron sputtering coating method.
  • the alternate magnetic layer 20 and the dielectric layer 30 are formed by alternate sputtering in the DC sputtering mode and the radio frequency sputtering mode respectively.
  • the multiple cracks 31 divide the continuous composite layer into several tiny regions, thereby significantly increasing the overall resistivity of the magnetic thin film 100 .
  • a region may be a region defined by three or more cracks 31 .
  • the area of each region along the above-mentioned cross-sectional direction is about 0.001mm 2 -0.3mm 2 .
  • the resistivity is about 0.01 ⁇ m.
  • the resistivity of the entire magnetic thin film 100 with the cracks 31 is 0.2 ⁇ m-20000 ⁇ m.
  • the composition, thickness, film compactness, crystal orientation, grain size, internal stress, etc. of the magnetic layer 20 and the dielectric layer 30 can be adjusted, and the resonance frequency can be adjusted to obtain High magnetic permeability in different frequency ranges.
  • the characteristics of the single-layer magnetic layer 20 material such as the nanocrystalline effect and the high proportion of interface atoms can be kept to the greatest extent, and the shape of the magnetic layer 20 with a nanometer thickness can be maintained.
  • the resulting magnetic anisotropy can still have the characteristics of high magnetic permeability.
  • the composition of the magnetic layer 20 can be ferromagnetic metal or ferromagnetic alloy, such as Fe, Co, Ni, FeSiAl alloy, FeNi alloy, FeCo alloy, FeCoNi alloy, FeCr alloy, FeCoCr alloy, FeB alloy.
  • the selection of magnetic components usually considers materials with a large saturation magnetization, which is critical to improving the magnetic permeability; in addition, the main consideration is that the magnetic resonance frequency is close to the operating frequency of the absorbing film material.
  • the above selection of the composition of the magnetic layer 20 covers common materials used for GHz operating frequency, but is not limited to the above selection of materials.
  • Magnetic alloy materials generally have high saturation magnetization and low coercive force, and it is easier to obtain high magnetic permeability than other materials.
  • the composition of each magnetic layer 20 is a magnetic alloy, and the magnetic alloy includes one or more of FeNi alloy, FeSiAl alloy, FeCo alloy and other magnetic alloys.
  • each magnetic layer 20 is nanoscale, preferably 2nm-100nm, more preferably 5nm-40nm. Too thick magnetic layer 20 will cause the growth of columnar crystals, resulting in excessively large crystal grains, increasing the coercive force; it will also cause a demagnetization field to be formed inside the magnetic layer 20; the larger magnetic layer 20 will also cause the layer to be divided into With multiple magnetic domains, the domain wall will pin the magnetization vector movement, reducing the magnetic permeability, resulting in the deterioration of high-frequency characteristics, thereby significantly reducing the magnetic permeability.
  • the magnetic property of the product obtained by too small magnetic layer 20 thickness becomes poor, because a continuous magnetic film layer has not been formed when the sputtering thickness is small; it may also be because the proportion of magnetic layer 20 in the total thickness is too low, resulting in saturation magnetization Low, so that it is impossible to obtain multilayer films with high magnetic permeability.
  • the composition of the dielectric layer 30 is at least one of insulating oxides, nitrides, and fluorides, preferably silicon dioxide, aluminum oxide, magnesium oxide, aluminum nitride, silicon nitride, magnesium fluoride, fluoride at least one of calcium.
  • each dielectric layer 30 is 2nm-10nm.
  • the dielectric layer 30 separates the adjacent magnetic layer 20 into nanometer-thick film layers, which guarantees high magnetic performance, and therefore needs to have a certain thickness to form a substantially continuous film layer.
  • the dielectric layer 30 also has the function of adjusting the overall internal stress of the film. If the thickness of the dielectric layer 30 is too thin and the sputtering time is too short, on the one hand the dielectric layer 30 has no time to grow into a continuous film layer, resulting in increased defects and internal Stress increases.
  • the dielectric layer 30 can also be used to regulate the magnetic interaction between adjacent magnetic nano-layers 20 , and the magnetic exchange magnetic coupling between adjacent magnetic layers 20 can be formed through the non-magnetic layer 20 to improve ferromagnetism. Therefore, the thickness of each dielectric layer 30 is generally within 10 nm, taking the magnetic exchange length of the material of the magnetic layer 20 as a reference. If the thickness of the dielectric layer 30 is too thick, the time cost will be increased due to the relatively low sputtering efficiency of the non-magnetic layer 20 .
  • the total number of layers of the plurality of magnetic layers 20 and the plurality of dielectric layers 30 is greater than 50, and the total thickness is greater than 300 nm, preferably 1 ⁇ m-10 ⁇ m. If the thickness of the composite layer is too small, on the one hand, it is not enough to produce sufficient absorption performance, that is, the product of the imaginary part of the magnetic permeability and the thickness is not high enough; on the other hand, when the thickness is small, the accumulated stress of the multilayer film is not enough to cause cracks in the film31 . Experimental data shows that thin film materials need at least 300 nm to produce obvious cracks 31 , and cracks 31 can be generated more stably when the thickness is more than 1 micron.
  • the maximum thickness of the film should not exceed 10 microns, otherwise the accumulation of internal stress is too large, which will easily reduce the adhesion of the film layer and peel off. On the other hand, if the thickness is too large, it will take too long and the commercial value will be low.
  • the crack 31 includes at least one of a penetrating type and a semi-penetrating type.
  • the penetrating type is: along the stacking direction of each layer of the composite layer (thickness direction of the composite layer), the extension depth of the crack 31 is equal to the thickness of the composite layer, that is, the crack 31 penetrates the composite layer.
  • the semi-penetrating type is: along the stacking direction of each layer of the composite layer (thickness direction of the composite layer), the extension depth of the crack 31 is smaller than the thickness of the composite layer, that is, the crack 31 does not penetrate the composite layer, For example, only a part of the magnetic layer 20 and a part of the dielectric layer 30 are penetrated.
  • the generation of crack 31 is due to the chapping caused by the stress release caused by the polymer matrix softening to a certain extent under the action of sputtering heat after the internal stress of the multi-layer thin film of the composite layer is accumulated to a certain extent. Due to the different degrees of stress release, the lines formed by cracks may be penetrating or semi-penetrating, but all of them can significantly increase the resistivity of the multilayer film. Based on the mechanism of the crack 31 , the opening width of the crack 31 is usually small, generally less than 2 ⁇ m; the crack 31 with too large opening is likely to cause tearing of the polymer substrate, or significantly affect the magnetic properties.
  • the substrate 10 is a flexible substrate with a thickness of 5 ⁇ m-50 ⁇ m, a glass transition temperature of 25° C.-100° C., and a melting point greater than 100° C.
  • the flexible base is a polymer material, preferably, the material of the flexible base can be polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), polybutadiene-benzene Polyethylene (PBS), polyphenylene sulfide (PPS), acrylonitrile-butadiene-styrene plastic (ABS), polyethylene terephthalate-1,4-cyclohexanedimethanol (PETG) , one of polystyrene (PS).
  • PET polyethylene terephthalate
  • PMMA polymethyl methacrylate
  • PBS polybutadiene-benzene
  • PPS polyphenylene sulfide
  • ABS acrylonitrile-butadiene-styrene plastic
  • PETG polyethylene tere
  • the substrate 10 has an influence on the generation of cracks 31 , and if the substrate is rigid, it is not conducive to the generation of cracks 31 , and will cause the film layer to break and fall off when a certain film thickness is reached.
  • a certain amount of heat will be generated and lead to a temperature rise, usually the temperature does not exceed 100°C, so it is required to use a glass transition temperature of 25°C-100°C , a flexible polymer with a melting point greater than 100°C is used as a film-forming substrate.
  • the process of forming the crack 31 will tear the polymer substrate; when the thickness of the flexible polymer substrate is too thick, especially when the thickness is higher than 50 ⁇ m, it usually does not meet the requirements.
  • Application requirements for ultra-thin film layer thickness are not met.
  • the magnetic thin film 200 of the second embodiment of the present application is basically similar to the magnetic thin film 100 of the first embodiment, and also includes a substrate 10 and a composite layer stacked on the substrate 10, the composite layer includes a plurality of magnetic Layer 20 and a plurality of dielectric layers 30, the plurality of magnetic layers 20 and the plurality of dielectric layers 30 are arranged alternately; the difference is that a plurality of transition layers 40 are also included, and each adjacent pair of magnetic layers 20 and dielectric layers 30 to form a transition layer 40 .
  • the dielectric layer 30 , the transition layer 40 , the magnetic layer 20 , and the transition layer 40 are sequentially laminated on the substrate 10 in sequence.
  • the closest to the substrate 10 in the magnetic thin film 200 is a dielectric layer 30 , but it is not limited thereto, and may also be a magnetic layer 20 .
  • the farthest from the substrate 10 in the magnetic thin film 100 is a dielectric layer 30 , but it is not limited thereto.
  • the furthest from the substrate 10 is a magnetic layer 20 .
  • the transition layer 40 contains the magnetic material in the magnetic layer 20 and the insulating material in the dielectric layer 30 .
  • the thickness of the transition layer 40 is less than or equal to 10 nm.
  • the transition layer 40 acts as a buffer transition between the magnetic layer 20 and the medium layer 30 , thereby improving the bonding strength between the magnetic layer 20 and the medium layer 30 .
  • the total number of layers of the plurality of magnetic layers 20 , the plurality of transition layers 40 and the plurality of dielectric layers 30 is greater than 50, and the total thickness is greater than 300 nm, preferably 1 ⁇ m-10 ⁇ m.
  • Internal stress control of the multilayer thin film material is the key to realizing the magnetic properties and the formation of cracks 31 , and the transition layer 40 can also adjust the internal stress and reduce the influence on the magnetic properties.
  • the dielectric layer 30 is sputtered by a radio frequency method, it usually has the characteristics of dense film and small internal stress, which is in sharp contrast to the magnetic layer 20 of DC sputtering with many defects and large internal stress, so the sputtering of the material of the dielectric layer 30 can play a role.
  • the internal stress is closely related to the magnetic properties, and it is also the source of the crack 31 structure of the multilayer film.
  • the transition layer 40 is obtained by co-sputtering the material of the magnetic layer 20 and the material of the dielectric layer, and the volume ratio of the magnetic material is between 20% and 80%, preferably between 50% and 80%. 30 can reduce the weakening of the magnetic exchange effect, and can further adjust the stress of the multilayer film, but the thickness should not exceed 10nm, so as not to have a significant impact on the magnetic properties. However, if the internal stress level is appropriate, there is no need to add a transition layer. According to the function of the transition layer 40, it is not limited to the co-sputtering of the substance of the magnetic layer 20 and the substance of the dielectric layer 30, but also can be independent sputtering of the third target material.
  • the present application also provides an electronic device using the above-mentioned magnetic film 100 or magnetic film 200 .
  • the magnetic thin film 100 or the magnetic thin film 200 is a wave-absorbing material with high magnetic permeability in the radio frequency and microwave band, and can be arranged at the position where the electronic device 300 needs to absorb electromagnetic waves, effectively absorbing electromagnetic waves and avoiding interference noise.
  • the magnetic film 100 or the magnetic film 200 can be directly attached to a noise source (not shown in the figure, such as a circuit, a chip, a module, a high-speed signal line, etc.) that radiates electromagnetic noise, or placed on a noise source On the way to propagate the noise to the receiver (not shown).
  • FIG. 3A and FIG. 3B exemplarily show the internal environment of the electronic device 300 provided by the present application, and the electronic device 300 is used as a mobile phone for illustration.
  • an electronic device 300 includes: a display screen 301 , a middle frame 310 , and a circuit board 303 stacked in sequence.
  • FIG. 3A and FIG. 3B only schematically show some components of the electronic device 300, and the actual shape, actual size and actual configuration of these components are not limited by FIG. 3A and FIG. 3B.
  • the surface of the display screen 301 close to the middle frame 310 is provided with a layered metal piece 330, the metal piece 330 can prevent the imaging unit in the display screen 301 from being interfered by electromagnetic signals, and can also provide the display screen 301 with good heat dissipation.
  • the display screen 301 may be a liquid crystal display (liquid crystal display, LCD), a light emitting diode (light emitting diode, LED) or an organic light emitting semiconductor (organic light-emitting diode, OLED), etc. limit.
  • the middle frame 310 is made of metal and mainly plays a supporting role for the whole machine. As shown in FIG. 3B , the metal part 330 of the display screen 301 cooperates with the middle frame 310 to form a cavity 350 , and the cavity 350 has a metal wall (or a metal frame). In this embodiment, the cavity 350 is not completely closed.
  • the electronic device 300 in order to transmit electrical signals between the display screen 301 and the electronic components (such as a processor) on the circuit board 303, the electronic device 300 is provided with a connecting line 305, and the connecting line 305 passes through the cavity 350 to make the display screen 301 is electrically connected to the circuit board 303 , that is, one end of the connection line 305 is electrically connected to the display screen 301 , and the other end extends through the middle frame 310 to be electrically connected to the circuit board 303 .
  • the connection line 305 can be a mobile industry processor interface (Mobile Industry Processor Interface, MIPI) or a flexible circuit board.
  • the electronic device 300 may further include a battery 304 .
  • the battery 304 and the circuit board 303 are both located on the same side of the middle frame 310 and adjacent to each other.
  • a metal layer (not shown) is also provided on the inside or on the surface of the battery 304 .
  • the electronic device 300 may further include a signal transmitter.
  • the signal transmitter is an antenna unit 302 for performing wireless communication, but it is not limited thereto.
  • the antenna unit 302 may be disposed on one or more sides outside the cavity 350 .
  • the antenna unit 302 may be a frame antenna, a flexible printed circuit (FPC) antenna or other types of antennas.
  • the components (electronic components) in the electronic device 300 often generate electromagnetic waves when powered on, and these electromagnetic waves will interfere with the antenna unit 302 , so these components are the interference source/noise source of the antenna unit 302 .
  • the connection line 305 of this embodiment transmits electrical signals, it will generate an interference signal as an interference source, because the cavity 350 is a metal wall (such as the metal part 330, the middle frame 310 and the side frame), and the interference signal cannot penetrate The metal wall can only transmit inside the cavity 350 , and the direction of the arrow shown in FIG. 3 represents the propagation direction of the interference signal.
  • the interference signal is transmitted to the antenna unit 302 located at the opening of the cavity 350 through the cavity 350 , which will affect the performance of the antenna unit 302 .
  • an existing method is to add a shielding cover at the interference source.
  • this connection line 305 as the interference source it is difficult to use the shielding cover to achieve shielding .
  • the magnetic film 100 or the magnetic film 200 is arranged in the cavity 350.
  • the magnetic film 100 or the magnetic film 200 is arranged on the middle frame 310. 305 )
  • the electromagnetic wave generated by the magnetic film 100 or 200 will be absorbed by the magnetic film 100 or 200 , making it difficult to transmit out of the cavity 350 , thereby preventing interference signals from affecting the antenna unit 302 .
  • the present application also provides a semiconductor package module 500, including an electronic component 510, a magnetic film 520 attached to the electronic component 510, and a metal shielding layer attached to the magnetic film 520 530.
  • the structure of the magnetic film 520 is basically the same as that of the above-mentioned magnetic film 100 and magnetic film 200, the only difference being that the base layer of the magnetic film 520 is different, which is a layer of plastic sealing material with a thickness of 5 ⁇ m-500 ⁇ m.
  • the material layer contains polymer resin, inorganic filler (such as silicon dioxide), and other functional components. That is, the multiple magnetic layers are alternately arranged and the multiple dielectric layers are directly deposited on the molding material layer.
  • the molding material layer is not only used to encapsulate the electronic components 510 , but also serves as a base of the magnetic film 520 .
  • the electronic component 510 may be an integrated circuit, an integrated circuit device, or a chip (such as a system-in-package chip) and the like.
  • the magnetic film 520 absorbs the noise of crosstalk inside the semiconductor packaging module 500, and the metal shielding layer 530 is used to prevent electromagnetic waves in the semiconductor packaging module 500 from radiating to the outside, passing through the magnetic film 520 and the metal The shielding layer 530 can effectively solve the noise interference problem of the semiconductor packaging module 500 .
  • a bonding layer (not shown) can also be selectively provided between the composite laminate of alternately arranging a plurality of magnetic layers and a plurality of dielectric layers and the substrate (molding material layer) to improve the connection between the two. connection strength.
  • the metal shielding layer 530 may be covered with a protective layer (not shown) to prevent the metal shielding layer 530 from being oxidized.
  • the present application also provides an electronic device (not shown in the figure), which includes the above-mentioned semiconductor package module 500 .
  • the electronic device further includes a casing, and the semiconductor packaging module 500 is located in the casing.
  • the electronic device includes a circuit board, and the semiconductor package module 500 is disposed on the circuit board.
  • the present application also provides a method for preparing a magnetic thin film, including:
  • a composite layer is formed on one surface of the substrate, the composite layer includes a plurality of magnetic layers and a plurality of dielectric layers, and the plurality of magnetic layers and the plurality of dielectric layers are alternately arranged, that is, alternately circulated sputtering magnetic layers and dielectric layers; the thickness of each magnetic layer is 2nm-100nm; the thickness of each dielectric layer is 2nm-10nm; the total thickness of the plurality of magnetic layers and the plurality of dielectric layers is 50nm-10 ⁇ m;
  • the substrate may have a thickness of 5 ⁇ m-50 ⁇ m, a glass transition temperature of 25° C.-100° C., and a melting point greater than 100° C.
  • the base is a polymer material, preferably, the material of the base can be polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), polybutadiene-styrene ( PBS), polyphenylene sulfide (PPS), acrylonitrile-butadiene-styrene plastic (ABS), polyethylene terephthalate-1,4-cyclohexanedimethanol (PETG), poly One of styrene (PS).
  • PET polyethylene terephthalate
  • PMMA polymethyl methacrylate
  • PBS polybutadiene-styrene
  • PPS polyphenylene sulfide
  • ABS acrylonitrile-butadiene-styrene plastic
  • PETG polyethylene terephthalate-1,4-
  • the composition of the magnetic layer is ferromagnetic metal or ferromagnetic alloy, such as Fe, Co, Ni, FeSiAl alloy, FeNi alloy, FeCo alloy, FeCoNi alloy, FeCr alloy, FeCoCr alloy, FeB alloy.
  • the composition of the dielectric layer is at least one of insulating oxides, nitrides, and fluorides, preferably silicon dioxide, aluminum oxide, magnesium oxide, aluminum nitride, silicon nitride, magnesium fluoride, and calcium fluoride at least one of the
  • the magnetron sputtering coating equipment with DC and RF multi-target sputtering functions, automatic program control and reciprocating multi-layer sputtering functions is selected as the preparation equipment.
  • Each magnetic layer adopts DC sputtering method, set the sputtering pressure to 0.1Pa-10Pa, adjust the sputtering power and target base distance to make the sputtering rate reach 0.1nm/s-2nm/s, and the sputtering time of each layer is 5s-100s.
  • Each dielectric layer adopts radio frequency sputtering method, set the sputtering pressure 0.1Pa-10Pa, adjust the sputtering power and target base distance to make the sputtering rate reach 0.05nm/s-0.1nm/s, and the sputtering time of each layer is 5s-500s .
  • the preparation method further includes forming a transition layer between each adjacent magnetic layer and the medium layer, and the transition layer contains ferromagnetic metal or ferromagnetic alloy in the magnetic layer and insulating material in the medium layer.
  • the transition layer contains ferromagnetic metal or ferromagnetic alloy in the magnetic layer and insulating material in the medium layer.
  • the thickness of the transition layer is less than or equal to 10 nm.
  • the volume ratio of the magnetic alloy material is between 20% and 80%, preferably between 50% and 80%.
  • the transition layer is co-sputtered by DC and RF, the sputtering pressure is set at 0.2Pa-2.0Pa, the sputtering rate ratio between DC and RF sputtering is adjusted between 0.2-5, and the sputtering time of each layer is less than or equal to 50s.
  • the sputtering material should be sputtered at a higher sputtering rate; the lower the sputtering efficiency, the better the film quality , the accumulation of internal stress is not enough to cause cracks; the sputtering efficiency is too high, the multilayer structure is easy to be damaged, or even pulverized and peeled off.
  • the sputtering pressure is crucial to the sputtering rate and film quality. If the sputtering pressure is too low, the target is difficult to glow or the glow is unstable, and the sputtering effect is not good; Magnetic properties are affected.
  • the magnetic permeability of the magnetic thin film of the present application is high, which is 10-30 times higher than that of traditional wave-absorbing materials, and can reach 200-600; compared with the magnetic thin films prepared by other processes, Its resistivity is 10-1000 times higher, which greatly increases the skin depth and improves the impedance matching of electromagnetic waves; and it can still maintain high magnetic permeability when the thickness reaches the micron level. Therefore, the magnetic thin film of the present application exhibits excellent microwave absorption performance while maintaining an extremely thin thickness. It only needs 1/10 of the thickness of traditional microwave-absorbing materials to obtain comparable or even better microwave-absorbing performance.
  • the magnetic thin film of the present application has broad application prospects as a wave-absorbing material in the fields of electronic components, wireless communication, and radar absorbing stealth, and is especially suitable for electromagnetic interference and prevention in extremely thin thickness and wearable scenarios.
  • the preparation method of the magnetic thin film of the present application has the advantages of convenience and low cost, and can adjust the magnetic permeability, magnetic resonance frequency and resistivity.
  • the substrate made of PET Polyethylene terephthalate, polyethylene terephthalate
  • a thickness of 20 ⁇ m after cleaning and drying with absolute ethanol on the magnetron sputtering sample tray, vacuumize, and wait for the magnetron sputtering chamber
  • the process parameters argon gas flow rate is 40 sccm
  • sputtering pressure is 0.15 Pa
  • tray speed is 20 r/min
  • FeSiAl adopts DC sputtering
  • sputtering efficiency is 0.5nm/s
  • SiO 2 Using radio frequency sputtering, the sputtering efficiency is 0.05nm/s.
  • the thickness of each layer of FeSiAl magnetic alloy layer is 6nm, and the thickness of each layer of SiO2 dielectric layer is 2nm.
  • the thickness of the sputtering transition layer is 5nm.
  • FIG. 6 is a cross-sectional view of a scanning electron micrograph of a sample of the magnetic thin film of Example 1.
  • FIG. Fig. 7 is that the magnetic thin film that embodiment 1 obtains carries out the microstrip line test and obtains the absorptivity curve, it can be seen that the absorbing performance of the magnetic thin film of embodiment 1 reaches more than 90% to the electromagnetic wave absorption rate of 1-2GHz, shows excellent microwave absorption properties.
  • FeNi magnetic alloy layer and SiO2 medium layer According to the order of FeNi magnetic alloy layer and SiO2 medium layer, sputter alternately successively, every layer of FeNi magnetic alloy layer thickness 5nm, every layer of SiO2 medium layer thickness 2nm, when sputtering finishes 100 cycles, sputtering finishes, obtains FeNi/ SiO 2 multilayer magnetic film samples. Scanning electron microscope characterization results show that the sample has a total thickness of 0.7 ⁇ m and a good layered structure. The square resistance is measured by a four-probe resistance meter and the conductivity is calculated to be 3 ⁇ 10 5 S/m.
  • the magnetic film of Example 2 was tested by the single-port short-circuit waveguide method. As shown in FIG. 8 , the magnetic permeability of the magnetic film of Example 2 reached 270 at 0.6 GHz.
  • FeNi magnetic alloy layer and SiO2 medium layer According to the order of FeNi magnetic alloy layer and SiO2 medium layer, sputtering alternately successively, every layer of FeNi magnetic alloy layer thickness 15nm, every layer of SiO2 medium layer thickness 2nm, when sputtering has finished 40 cycles, sputtering finishes, obtains FeNi/ SiO 2 multilayer magnetic film samples. Scanning electron microscope characterization results show that the sample has a total thickness of 0.7 ⁇ m and a good layered structure. The square resistance is measured by a four-probe resistance meter and the conductivity is calculated to be 1.4 ⁇ 10 5 S/m.
  • the magnetic film of Example 3 was tested by the single-port short-circuit waveguide method. As shown in FIG. 9 , the magnetic permeability of the magnetic film of Example 3 reached 630 at 0.7 GHz.
  • each layer of FeNi magnetic alloy layer is 15nm, and the thickness of each layer of SiO2 medium layer is 2.5nm. After 70 cycles of sputtering, the sputtering ends to obtain FeNi /SiO 2 multilayer magnetic film samples.
  • the scanning electron microscope characterization results show that the sample has a total thickness of 1.2 ⁇ m and has a good layered structure.
  • the imaginary part of the magnetic permeability at 1.2 GHz is 180 measured by the single-port short-circuit waveguide method, and the four-probe resistance tester is used Its square resistance was tested and its electrical conductivity was calculated to be 3 ⁇ 10 5 S/m, with semi-penetrating lines.
  • the scanning electron microscope characterization results show that the total thickness of the sample is 1.1 ⁇ m, and it has a good layered structure.
  • the imaginary part of the magnetic permeability at 0.7 GHz is 307 measured by the single-port short-circuit waveguide method, and the four-probe resistance tester is used Measure its square resistance and calculate its conductivity as 3 ⁇ 10 6 S/m.
  • Example 5 The magnetic thin film of Example 5 was tested by a vibrating sample magnetometer, as shown in the static magnetic performance curve shown in FIG. 10 , it was found that its coercive force was only 0.6 Oe, showing excellent magnetic performance.
  • the scanning electron microscope characterization results show that the sample has a total thickness of 2.1 ⁇ m and has a good layered structure.
  • the imaginary part of the magnetic permeability at 1.05 GHz is 215 by using the single-port short-circuit waveguide method, and the four-probe resistance tester is used Its square resistance was tested and its electrical conductivity was calculated to be 500S/m, with a penetrating crack structure.
  • FIG. 11 is an XRD (X-ray diffraction, X-ray diffraction) spectrum of the sample of the magnetic thin film of Example 6, and the characteristic peaks of the base PET and the magnetic alloy layer FeNi 3 can be detected. According to the XRD diffraction pattern, the calculated average grain size is 5nm.
  • argon gas flow rate is 40sccm
  • sputtering pressure is 0.35Pa
  • tray speed is 20r/min
  • FeNi adopts DC sputtering
  • sputtering efficiency is 0.42nm/s
  • SiO2 adopts radio frequency sputtering
  • sputtering efficiency is 0.063nm/s s.
  • the scanning electron microscope characterization results show that the sample has a total thickness of 2.1 ⁇ m and has a good layered structure.
  • the imaginary part of the magnetic permeability at 1.35 GHz is 350 by using the single-port short-circuit waveguide method, and the four-probe resistance tester is used Test its square resistance and calculate its conductivity as 50S/m.
  • FIG. 12 is a transmission microscope photograph of a sample of the magnetic thin film of Example 7.
  • FIG. 12 It can be seen from Fig. 12 that there are penetrating cracks, and the cracks are surrounded by irregular polygonal units, and the area of the polygonal units is 0.001mm 2 -0.3mm 2 .
  • argon gas flow rate is 40sccm
  • sputtering pressure is 0.35Pa
  • tray speed is 20r/min
  • FeNi adopts DC sputtering
  • sputtering efficiency is 0.42nm/s
  • SiO2 adopts radio frequency sputtering
  • sputtering efficiency is 0.063nm/s s.
  • each layer of FeNi magnetic alloy layer thickness is 9.5nm
  • each layer of co-sputtering transition layer is 3.5nm
  • each The thickness of the SiO 2 medium layer is 2nm.
  • FIG. 13 is a microscope reflection photograph of a sample of the magnetic thin film of Example 8.
  • FIG. 13 From Figure 13, it can be seen that the through-type cracks are irregular polygons, and the crack width is about 0.1 ⁇ m.
  • argon gas flow rate is 40sccm
  • sputtering pressure is 0.35Pa
  • tray speed is 20r/min
  • FeNi adopts DC sputtering
  • sputtering efficiency is 0.42nm/s
  • SiO2 adopts radio frequency sputtering
  • the sputtering efficiency was 0.063nm/s.
  • each layer of FeNi magnetic alloy layer thickness is 9.5nm
  • each layer of co-sputtering transition layer is 3.5nm
  • each The thickness of the SiO 2 dielectric layer is 2nm.

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Abstract

本申请提供一种磁性薄膜（100），包括基底（10）和复合层，复合层包括层叠的多个磁性层（20）和绝缘的多个介质层（30），多个磁性层（20）和多个介质层（30）在基底（10）一侧层叠交替排布；每一个磁性层（20）的厚度为2nm-100nm；每一个介质层（30）的厚度为2nm-10nm；复合层包括非周期性分布的多条裂纹（31），至少部分裂纹（31）沿垂直复合层的层叠方向的横截面的延伸方向不同，至少部分的裂纹（31）沿垂直复合层的层叠方向的横截面非直线延伸。本申请还提供一种应用磁性薄膜的电子设备和半导体封装模组、磁性薄膜的制备方法，磁性薄膜为在射频微波频段具有高磁导率的吸波材料，磁性薄膜在厚度达到微米级的条件下仍具有高磁导率和高电阻率。

Description

磁性薄膜及其制备方法、半导体封装模组和电子设备
相关申请的交叉引用
本申请要求在2021年5月27日提交中国专利局、申请号为202110586639.2、申请名称为“磁性薄膜及其制备方法、半导体封装模组和电子设备”的中国专利的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请涉及一种磁性薄膜及其制备方法，以及应用该磁性薄膜的半导体封装模组和电子设备。
背景技术
随着通讯和终端技术的快速发展，电子元器件及终端设备不断趋于微型化、小型化及多频化，导致狭小的空间里充斥着大量不同频率的电磁波，且电子元器件之间、电子设备之间及电子设备与外界环境之间的电磁干扰也急剧增加。解决电磁干扰问题的方法通常分为屏蔽和吸收两种。相对而言，采用吸波材料对多余电磁波进行吸收的方式能够避免二次污染，而且使用更为方便和灵活，是优先考虑的方案。但电子设备的高集成度、非常有限的物理空间及复杂的电磁环境，对吸波材料的厚度及吸波性能提出了极高的要求。
发明内容
本申请实施例第一方面提供了一种磁性薄膜，包括：
基底；
位于所述基底一侧的复合层，所述复合层包括层叠的多个磁性层和绝缘的多个介质层，所述多个磁性层和所述多个介质层在所述基底一侧交替排布；
每一个磁性层的厚度为2nm-100nm；每一个介质层的厚度为2nm-10nm；所述复合层的厚度为50nm-10μm；所述复合层包括多条裂纹，所述多条裂纹非周期性分布，至少部分所述多条裂纹沿垂直所述复合层的层叠方向的横截面的延伸方向不同，至少部分所述多条裂纹沿垂直所述复合层的层叠方向的横截面非直线延伸。
相邻的磁性层被纳米级厚度的介质层分隔后，可最大限度地保持单层磁性薄层材料的纳米尺寸效应、界面原子高占比等特性，保持纳米厚度的磁性层的形状导致的磁各向异性，因而仍能具有高磁导率的特点。
本申请实施方式中，所述多条裂纹为溅射形成所述多个磁性层和所述多个介质层的过程中，所述多个磁性层和所述多个介质层中的内应力释放导致。
本申请实施方式中，所述裂纹将所述复合层分割成若干区域。
本申请实施方式中，每一个所述区域沿所述横截面方向的面积为0.001mm 2-0.3mm 2。
所述裂纹将连续的复合层分割成若干微小区域，从而显著提高所述磁性薄膜整体的电阻率。例如，若所述磁性薄膜中未形成裂纹，则电阻率约为0.01μΩm左右，而本申请中，形成有所述裂纹的所述磁性薄膜整体的电阻率达到0.2μΩm-20000μΩm。
本申请实施方式中，所述多条裂纹至少包括以下中的至少一种：沿所述复合层各层的堆叠方向，延伸深度等于所述复合层的堆叠高度的裂纹；以及沿所述复合层各层的堆叠方向，延伸深度小于所述复合层的堆叠高度的裂纹。
裂纹的产生是由于复合层的多层薄膜的内应力累积到一定程度后，基体在溅射热作用下产生一定程度的软化，应力释放而引起的皲裂；由于应力释放的程度不同，裂纹可能贯穿复合层，也可能是未贯穿复合层，但都能够显著增加多层薄膜的电阻率。
本申请实施方式中，每一条裂纹的开口宽度小于2μm。
基于裂纹产生的机制，裂纹的开口宽度通常较小，一般小于2微米；宽度过大的裂纹容易造成基底的撕裂，或者显著影响磁性能。
本申请实施方式中，每一个磁性层的厚度为5nm-40nm。
过厚的磁性层会造成柱状晶的生长，导致晶粒过大，增加矫顽力；还会导致磁性层内部形成一个退磁场；厚度较大的磁性层也会使得层内分割成多个磁畴，畴壁会对磁化矢量运动起到钉扎，使磁导率降低，导致高频特性的恶化，从而显著降低磁导率。过小的磁性层厚度所得的产物磁性能变差，因为在溅射厚度较小时尚未形成连续的磁性薄膜层；还可能因为磁性层在总厚度中所占比例过低，导致饱和磁化强度较低，从而无法获得高磁导率的多层薄膜。
本申请实施方式中，每一个磁性层的材质为铁磁性金属或铁磁性合金。
铁磁性金属或铁磁性合金一般具有高的饱和磁化强度，低的矫顽力，相对于其他材料更容易获得高的磁导率。
本申请实施方式中，所述介质层的成份为绝缘的氧化物、氮化物、氟化物中的至少一种。
本申请实施方式中，每相邻的磁性层与介质层之间形成有过渡层，所述过渡层的厚度小于等于10nm；所述过渡层含有所述磁性层中的磁性材料和所述介质层中的绝缘材料。
所述过渡层充当磁性层与介质层之间的缓冲过渡，从而提升磁性层与介质层之间的结合强度。
本申请实施方式中，所述磁性材料在所述过渡层中的体积占比在20％到80％之间。
本申请实施方式中，所述多个磁性层和多个介质层的总层数大于50层，总厚度大于300nm。
若所述多个磁性层和所述多个介质层总的厚度太小，一方面不足以产生足够的吸收性能，即磁导率虚部与厚度乘积不够高；另一方面，厚度较小时多层薄膜累积的应力不足以使得薄膜产生裂纹。实验数据表明，薄膜材料至少需要300nm才可产生明显的裂纹，1微米以上时才可较为稳定地产生裂纹。
本申请实施方式中，所述多个磁性层和多个介质层的总厚度为1μm-10μm。
所述多个磁性层和多个介质层的总厚度最大不超过10微米，否则内应力累积过大，容易使得膜层附着力下降从而剥落，另一方面，过大的厚度耗时过长，商业价值较低。
本申请实施方式中，所述基底为柔性的，厚度为5μm-50μm，玻璃转化温度为25℃-100℃，熔点大于100℃。
本申请实施方式中，所述基底的材质为聚对苯二甲酸乙二醇酯、聚甲基丙烯酸甲酯、聚丁二烯-苯乙烯、聚苯硫醚、丙烯腈-丁二烯-苯乙烯塑料、聚对苯二甲酸乙二醇酯-1,4-环己烷二甲醇酯、聚苯乙烯中的一种。
所述基底对于裂纹的产生有影响，若是刚性强的基底，则不利于裂纹的产生，且会在达到一定膜层厚度时导致膜层破碎脱落。在溅射形成所述多个磁性层和所述多个介质层的过程 中会产生一定的热并导致升温，通常温度不超过100℃，因而要求采用玻璃转化温度在25℃-100℃，熔点大于100℃的柔性高分子作为成膜基底。厚度过薄的柔性高分子基底，特别是厚度低于5μm时，形成裂纹的过程会将高分子基底撕裂；厚度过厚的柔性高分子基底，特别是厚度高于50μm时，通常不满足应用对超薄膜层厚度的要求。
本申请实施方式中，所述基底为塑封材料层，厚度为5μm-500μm。
所述多个磁性层和多个介质层可沉积在用以封装电子元器件，例如芯片等，的塑封材料层上，有效吸收塑封材料层封装的内部相互串扰的噪声。
本申请实施例第二方面提供了一种半导体封装模组，包括电子元器件、附着在所述电子元器件上的上述的磁性薄膜、以及附着在所述磁性薄膜上的金属屏蔽层；所述磁性薄膜的基底层为塑封材料层。
所述磁性薄膜吸收所述半导体封装模组内部相互串扰的噪声，所述金属屏蔽层用于避免半导体封装模组中的电磁波辐射到外部，通过所述磁性薄膜和所述金属屏蔽层可有效解决半导体封装模组的噪声干扰问题。
本申请实施例第三方面提供了一种电子设备，包括电路板和位于所述电路板上的第二方面所述的半导体封装模组。
本申请实施例第四方面提供了一种电子设备，包括壳体位于所述壳体中的第二方面所述的半导体封装模组。
本申请实施例第五方面提供了一种电子设备，包括辐射电磁波的噪声源和第一方面所述的磁性薄膜，所述磁性薄膜贴附在噪声源上或者设置在噪声源传播噪声的路径上。
所述磁性薄膜为在射频微波频段具有高磁导率的吸波材料，可设置在所述电子设备需要进行吸收电磁波的位置处以对多余的电磁波进行吸收。
本申请实施方式中，所述电子设备包括金属材质的中框和金属件，所述中框和所述金属件配合构成腔体，所述腔体中设置有所述噪声源，所述腔体外设置有信号发射器，所述磁性薄膜位于所述腔体中。
噪声源产生的干扰噪声通常沿所述中框和所述金属件之间的腔体向外传播，因此在所述腔体中设置磁性薄膜，当噪声源产生的电磁波经过磁性薄膜时会被磁性薄膜吸收，难以传输出腔体，从而避免干扰信号影响所述信号发射器。
本申请实施例第六方面提供了一种磁性薄膜的制备方法，包括：
提供基底；
采用溅射法，在所述基底的一侧形成复合层，所述复合层包括多个磁性层和多个介质层，所述多个磁性层和所述多个介质层在所述基底的一侧为交替排布；
每一个磁性层的厚度为2nm-100nm；每一个介质层厚度为2nm-10nm；所述复合层的厚度为50nm-10μm；
溅射形成所述复合层的过程中，所述复合层中的内应力释放导致所述复合层中形成非周期性分布的多条裂纹，至少部分所述多条裂纹沿垂直所述复合层的层叠方向的横截面的延伸方向不同，至少部分所述多条裂纹沿垂直所述复合层的层叠方向的横截面非直线延伸。
本申请的磁性薄膜的制备方法相对于现有的光刻法等制备图案化的方式，具有便捷、低成本的优势，并且可以对磁导率、磁共振频率和电阻率进行调节。
本申请实施方式中，每一个磁性层采用直流溅射方式，设置溅射气压为0.1Pa-10.0Pa，溅射速率为0.1nm/s-2nm/s，每层溅射时间5s-100s。
本申请实施方式中，每一个介质层采用射频溅射方式，设置溅射气压为0.1Pa-10.0Pa，溅射速率为0.05nm/s-0.1nm/s，每层溅射时间5s-500s。
为了使溅射过程中，薄膜能够累积足够的内应力产生裂纹，在溅射时应使溅射材料以较高的溅射速率进行溅射；较低的溅射效率，成膜质量好，内应力积累不足难以产生裂纹；溅射效率太高，多层结构容易破坏，甚至粉化脱落；此外，磁控溅射过程中，溅射气压对于溅射速率及成膜质量至关重要。溅射气压过低，靶材难以启辉或者辉光不稳定，溅射效果不佳；溅射气压过高，溅射出来的靶材粒子与气体碰撞机会增多，影响成膜附着力，并对磁性能造成影响。
本申请实施方式中，所述制备方法还包括在每相邻的磁性层与介质层之间形成过渡层，所述过渡层含有所述磁性层中的磁性材料和所述介质层中的绝缘材料，所述过渡层的厚度为小于等于10nm。
本申请实施方式中，所述过渡层采用直流和射频共溅射的方式，设置溅射气压为0.1Pa-10.0Pa，调节直流与射频溅射之间的溅射速率比介于0.2-5之间，每层溅射时间小于等于50s。
附图说明
图1是本申请第一施例的磁性薄膜的剖面示意图。
图2是本申请第二实施例的磁性薄膜的剖面示意图。
图3A和图3B是本申请实施例的电子设备的分解示意图和剖面示意图。
图4是本申请实施例的半导体封装模组的剖面示意图。
图5是本申请实施例磁性薄膜的制备方法流程图。
图6是实施例1的磁性薄膜的扫描电镜图断面图。
图7是实施例1的磁性薄膜的吸收率曲线。
图8是实施例2的磁性薄膜的磁导率图谱。
图9是实施例3的磁性薄膜的磁导率图谱。
图10是实施例5的磁性薄膜的静磁性能曲线。
图11是实施例6的磁性薄膜的X射线衍射图谱。
图12是实施例7的磁性薄膜的显微镜透射照片。
图13是实施例8的磁性薄膜的显微镜反射照片。
主要元件符号说明
磁性薄膜 100、200、520
基底 10
磁性层 20
介质层 30
裂纹 31
过渡层 40
电子设备 300
中框 310
金属件 330
腔体 350
连接线路 305
显示屏 301
天线单元 302
电路板 303
电池 304
半导体封装模组 500
电子元器件 510
金属屏蔽层 530
具体实施方式
下面结合本申请实施例中的附图对本申请实施例进行描述。
在一种吸波材料中，是将磁性吸收剂填充到高分子基体中形成复合材料，使其兼具磁性材料的高磁导率、高磁损耗与高分子复合材料的柔性和易加工性，并获得高绝缘性。磁性吸收剂一般选择具有高磁导率的磁性微粉，根据吸波材料作用的频率不同，通常有铁氧体(<100MHz)、软磁合金(100MHz-3GHz)、羰基铁粉(3-18GHz)几种基本类型。在无线通讯终端中，常用软磁合金粉作为磁性吸收剂，包括FeNi系合金、FeSiAl系合金、FeSi系合金等等。为了提高磁导率，磁性吸收剂会被加工成片状微粉，并且尽可能进行取向排列和高填充。因为磁性吸收剂的形状各向异性使其突破Snoek极限的限定，获得更高的高频磁导率；而它们的取向排列可增强各向异性的带来的磁导率增强效果；尽可能高的填充可增大磁性物质含量，提高材料的饱和磁化强度并相应地带来磁导率的提高。而为了在高填充条件下仍能获得高电阻率，通常会对磁性吸收剂的表面进行绝缘处理，使其可达到优异的绝缘效果。通常，这类吸波材料在10MHz可以达到最高250的磁导率实部，20左右的虚部值；磁导率虚部的峰值在10-100MHz之间，约可达到60-80；随着频率升高，磁导率快速下降，在1GHz仅达到5-10左右的实部值，约10到20的虚部值。因而，在1GHz以上的高频率，吸波材料磁导率通常十分有限。
本申请的实施例提供一种磁性薄膜，其为在射频微波频段具有高磁导率的吸波材料。所述磁性薄膜在厚度达到微米级的条件下仍具有高磁导率和高电阻率。
请参阅图1，本申请第一实施例的磁性薄膜100，包括基底10和位于所述基底10一侧的复合层。所述复合层包括层叠在所述基底10一表面上的多个磁性层20和多个介质层30。图1所示的Z轴代表所述复合层的各层的层叠方向，Y轴代表垂直纸面的方向，X轴和Y轴共同界定所述磁性薄膜100的横截面方向。所述多个磁性层20和所述多个介质层30交替排布。所述多个磁性层20和所述多个介质层30的总厚度为50nm-10μm，即所述复合层的厚度为50nm-10μm。本申请涉及的数据范围如无特别备注说明均包括端值。
本实施例中，所述磁性薄膜100中最接近所述基底10的是一介质层30，但不限于此，也可为一磁性层20。本实施例中，所述磁性薄膜100中最远离所述基底10的是一磁性层20，不限于此，优选最远离所述基底10的是一介质层30。
所述基底10上的复合层中形成有无规则的多条裂纹31的纹路，所述多条裂纹31在显微镜下可以清楚的看到，具体请参图12和图13所示的显微镜透射照片和显微镜反射照片，图 12中无规则的浅色条纹和图13中无规则的深色条纹均为裂纹31。图12和图13的显微镜照片均为垂直所述复合层的层叠方向的横截面方向的照片，即X轴和Y轴界定的表面方向。可知，所述多条裂纹31的无规则是指多条裂纹31非周期性地分布。至少部分所述多条裂纹31沿垂直所述横截面的延伸方向不同，至少部分所述多条裂纹31沿横截面非直线延伸。
所述裂纹31为溅射形成所述复合层的过程中，所述复合层中的内应力释放导致薄膜开裂形成的。所述磁性薄膜100的制备采用磁控溅射镀膜法，在所述基底10上，分别采用直流溅射模式和射频溅射模式交替溅射形成交替的磁性层20与介质层30，由于磁性层20和介质层30二者与所述基底10的力学与热学性能的失配，随着溅射过程中薄膜缺陷的累积及内应力的不断增加，而后达到释放的水平，导致薄膜裂纹31产生，并扩展形成连续裂纹31，获得具有裂纹31结构的薄膜材料，从而在获得高的磁导率的同时，实现低的电导率。所述多条裂纹31将连续的复合层分割成若干微小区域，从而显著提高所述磁性薄膜100整体的电阻率。例如，一个区域可为由三条或以上裂纹31围绕而限定的区域。一些实施例中，每一个区域沿上述横截面方向的面积约为0.001mm 2-0.3mm 2。例如，若所述磁性薄膜100中未形成裂纹，则电阻率约为0.01μΩm左右，而本申请中，形成有所述裂纹31的所述磁性薄膜100整体的电阻率达到0.2μΩm-20000μΩm。
另一方面，通过对溅射条件的控制，可以实现对磁性层20和介质层30的成分、厚度、膜层致密性、晶向、晶粒大小、内应力等的调控，并调节共振频率获得不同频率范围的高磁导率。
相邻的磁性层20被纳米级厚度的介质层30分隔后，可最大限度地保持单层磁性层20材料的纳米晶效应、界面原子高占比等特性，保持纳米厚度的磁性层20的形状导致的磁各向异性，因而仍能具有高磁导率的特点。
磁性层20的成份可为铁磁性金属或铁磁性合金，例如Fe、Co、Ni、FeSiAl合金、FeNi合金、FeCo合金、FeCoNi合金、FeCr合金、FeCoCr合金、FeB合金。磁性成分的选择通常考虑饱和磁化强度较大的材料，这对于提高磁导率十分关键；此外主要考虑磁共振频率接近吸波薄膜材料的工作频率。因而，上述磁性层20成分的选择覆盖了GHz工作频率所用的常见材料，但并不局限于上述材料选择。磁性合金材料，一般具有高的饱和磁化强度，低的矫顽力，相对于其他材料更容易获得高的磁导率。优选地，每一个磁性层20的成分为磁性合金，所述磁性合金包括FeNi合金、FeSiAl合金、FeCo合金等磁性合金中的一种或几种。
每一个磁性层20的厚度为纳米级，优选为2nm-100nm，更优选为5nm-40nm。过厚的磁性层20会造成柱状晶的生长，导致晶粒过大，增加矫顽力；还会导致磁性层20内部形成一个退磁场；厚度较大的磁性层20也会使得层内分割成多个磁畴，畴壁会对磁化矢量运动起到钉扎，使磁导率降低，导致高频特性的恶化，从而显著降低磁导率。过小的磁性层20厚度所得的产物磁性能变差，因为在溅射厚度较小时尚未形成连续的磁性薄膜层；还可能因为磁性层20在总厚度中所占比例过低，导致饱和磁化强度较低，从而无法获得高磁导率的多层薄膜。
所述介质层30的成份为绝缘的氧化物、氮化物、氟化物中的至少一种，优选为二氧化硅、氧化铝、氧化镁、氮化铝、氮化硅、氟化镁、氟化钙中的至少一种。
每一个介质层30的厚度为2nm-10nm。所述介质层30将相邻的磁性层20分隔成厚度为纳米级别的膜层，是获得高磁性能的保障，因而需要具有一定的厚度，以形成基本连续的薄膜层。所述介质层30还具有调节薄膜整体的内应力的作用，若介质层30厚度太薄，溅射时间太短，一方面所述介质层30来不及生长成连续的膜层，导致缺陷增多，内应力增大。此外， 所述介质层30还可以用于调控相邻纳米磁性层20之间的磁相互作用，相邻磁性层20之间可以通过非磁性层20形成磁交换磁耦合作用，提高铁磁性。因而每个介质层30的厚度，以不超过磁性层20材料的磁交换作用长度为参考，通常是10nm以内。介质层30的厚度过厚，还会导致因为非磁性层20溅射效率相对较低而造成时间成本增加。
所述多个磁性层20和所述多个介质层30的总层数大于50层，总厚度大于300nm，优选为1μm-10μm。若复合层的厚度太小，一方面不足以产生足够的吸收性能，即磁导率虚部与厚度乘积不够高；另一方面，厚度较小时多层薄膜累积的应力不足以使得薄膜产生裂纹31。实验数据表明，薄膜材料至少需要300nm才可产生明显的裂纹31，1微米以上时才可较为稳定地产生裂纹31。薄膜的厚度最大不超过10微米，否则内应力累积过大，容易使得膜层附着力下降从而剥落，另一方面，过大的厚度耗时过长，商业价值较低。
所述裂纹31包括贯穿型和半贯穿型中的至少一种。贯穿型为：沿所述复合层各层的堆叠方向(所述复合层的厚度方向)，裂纹31的延伸深度等于所述复合层的厚度，即所述裂纹31贯穿所述复合层。半贯穿型为：沿所述复合层各层的堆叠方向(所述复合层的厚度方向)，裂纹31的延伸深度小于所述复合层的厚度，即所述裂纹31未贯穿所述复合层，例如，仅贯穿部分的磁性层20和部分的介质层30。裂纹31的产生是由于复合层的多层薄膜的内应力累积到程度后，高分子基体又在溅射热作用下产生一定程度的软化，应力释放而引起的皲裂。由于应力释放的程度不同，裂纹形成的纹路可能是贯穿的也可能是半贯穿的，但都能够显著增加多层薄膜的电阻率。基于裂纹31产生的机制，裂纹31的开口宽度通常较小，一般小于2μm；过大开口的裂纹31容易造成高分子基底的撕裂，或者显著影响磁性能。
本申请中，所述基底10为柔性基底，厚度为5μm-50μm，玻璃转化温度在25℃-100℃，熔点大于100℃。所述的柔性基底为高分子材料，优选的，所述柔性基底的材质可为聚对苯二甲酸乙二醇酯(PET)、聚甲基丙烯酸甲酯(PMMA)、聚丁二烯-苯乙烯(PBS)、聚苯硫醚(PPS)、丙烯腈-丁二烯-苯乙烯塑料(ABS)、聚对苯二甲酸乙二醇酯-1,4-环己烷二甲醇酯(PETG)、聚苯乙烯(PS)中的一种。所述基底10对于裂纹31的产生有影响，若是刚性强的基底，则不利于裂纹31的产生，且会在达到一定膜层厚度时导致膜层破碎脱落。在溅射形成所述多个磁性层20和所述多个介质层30的过程中会产生一定的热并导致升温，通常温度不超过100℃，因而要求采用玻璃转化温度在25℃-100℃，熔点大于100℃的柔性高分子作为成膜基底。厚度过薄的柔性高分子基底，特别是厚度低于5μm时，形成裂纹31的过程会将高分子基底撕裂；厚度过厚的柔性高分子基底，特别是厚度高于50μm时，通常不满足应用对超薄膜层厚度的要求。
请参阅图2，本申请第二实施例的磁性薄膜200，其与实施例一的磁性薄膜100基本相似，也包括基底10和层叠在所述基底10上的复合层，复合层包括多个磁性层20和多个介质层30，所述多个磁性层20和所述多个介质层30交替排布；区别在于还包括多个过渡层40，每相邻的一对磁性层20与介质层30之间形成一个过渡层40。本申请的一实施例中，按照介质层30、过渡层40、磁性层20、过渡层40的顺序依次循环层叠在所述基底10上。
本实施例中，所述磁性薄膜200中最接近所述基底10的是一介质层30，但不限于此，也可为一磁性层20。本实施例中，所述磁性薄膜100中最远离所述基底10的是一介质层30，不限于此，优选最远离所述基底10的是一磁性层20。
所述过渡层40含有所述磁性层20中的磁性材料和所述介质层30中的绝缘材料。所述过渡层40的厚度小于等于10nm。所述过渡层40充当磁性层20与介质层30之间的缓冲过渡， 从而提升磁性层20与介质层30的结合强度。
所述多个磁性层20、所述多个过渡层40和所述多个介质层30的总层数大于50层，总厚度大于300nm，优选为1μm-10μm。
多层薄膜材料的内应力控制是实现磁性能和裂纹31形成的关键，过渡层40的还可调节内应力并减小对磁性能的影响。由于介质层30采用射频方法溅射，通常具有膜层致密、内应力小的特点，与直流溅射的磁性层20缺陷多、内应力大形成鲜明对比，因而介质层30材料的溅射能够起到调节多层膜整体内应力和缺陷水平的作用，而内应力与磁性能密切相关，同时也是促成多层膜产生裂纹31结构的来源。过渡层40由磁性层20物质与介质层物质共溅射而得，磁性物质的体积占比在20％到80％之间，优选在50％-80％之间，因而相对于纯粹的介质层30而言可减少对磁交换作用的弱化，又能进一步调节多层膜的应力，但厚度不宜超过10nm，以免对磁性能造成明显影响。而对于内应力水平适当的情况，则可以不需要增加过渡层。根据过渡层40的作用，可不局限于磁性层20物质与介质层30物质的共溅射，也可以是第三种靶材的独立溅射。
本申请还提供应用上述磁性薄膜100或磁性薄膜200的电子设备。所述磁性薄膜100或磁性薄膜200为在射频微波频段具有高磁导率的吸波材料，可设置在所述电子设备300需要进行吸收电磁波的位置处，有效吸收电磁波，避免干扰噪声。所述磁性薄膜100或磁性薄膜200可直接贴附在辐射电磁波噪声的噪声源(图未示，例如为产生噪声的电路、芯片、模组、高速信号线等)上，或者是设置在噪声源传播噪声给受体(图未示)的路径上。
图3A和图3B示例性示出了本申请提供的电子设备300内部环境，以电子设备300为手机进行说明。如图3A所示，电子设备300包括依次层叠的：显示屏301、中框310、电路板303。图3A和图3B仅示意性的示出了电子设备300的一些部件，这些部件的实际形状、实际大小和实际构造不受图3A和图3B限定。
如图3B所示，显示屏301靠近中框310的表面设置有层状的金属件330，金属件330可以防止显示屏301中的成像单元受到电磁信号的干扰，同时还可以为显示屏301提供良好的散热。可选地，显示屏301可以是液晶显示器(liquid crystal display，LCD)，发光二极管(light emitting diode，LED)或者有机发光半导体(organic light-emitting diode，OLED)等，本申请对此并不做限制。
中框310为金属材质，主要起整机的支撑作用。如图3B所示，显示屏301的金属件330与中框310配合围成一腔体350，腔体350具有金属壁(或金属框)。本实施例中，腔体350为非完全封闭的腔体。
如图3B所示，为了实现显示屏301与电路板303上电子元件(例如处理器)之间传递电信号，电子设备300中设置有连接线路305，连接线路305穿过腔体350使显示屏301与电路板303电连接，即连接线路305一端电性连接显示屏301，另一端延伸穿过中框310与电路板303电连接。连接线路305可为移动产业处理器接口(Mobile Industry Processor Interface，MIPI)或柔性电路板等。
如图3B所示，电子设备300还可以包括电池304。本实施例中，电池304与电路板303均位于所述中框310的同侧且相邻设置。电池304的内部或表面也会设置有金属层(图未示)。
如图3B所示，电子设备300还可以包括信号发射器，本实施例中，信号发射器为用于进行无线通信的天线单元302，但不以此为限。在一种实现方式中，天线单元302可以设置于腔体350外的一个侧面或多个侧面。天线单元302可以是边框天线，柔性电路板(flexible  printed circuit，FPC)天线或者其他类型的天线。
电子设备300中的元件(电子元件)在上电时往往会产生电磁波，这些电磁波会对天线单元302形成干扰，因此这些元件是天线单元302的干扰源/噪声源。例如，本实施例的连接线路305在传输电信号时，作为干扰源会产生干扰信号，因为腔体350为金属壁(例如金属件330、中框310以及侧面的边框)，干扰信号无法穿透金属壁，只能在腔体350的内部进行传输，图3所示箭头方向代表干扰信号的传播方向。干扰信号经过腔体350传输到位于腔体350开口处的天线单元302，会对天线单元302的性能产生影响。为了减小干扰源对天线单元302等器件的影响，现有的一种方法是在干扰源处添加屏蔽罩，然而，对于这种连接线路305作为干扰源来说，很难用屏蔽罩实现屏蔽。
如图3B所示，因此在所述腔体350中设置磁性薄膜100或磁性薄膜200，本实施例中，磁性薄膜100或磁性薄膜200设置在所述中框310上，当噪声源(连接线路305)产生的电磁波经过磁性薄膜100或200时会被磁性薄膜100或200吸收，难以传输出腔体350，从而避免干扰信号影响所述天线单元302。
请参阅图4，本申请还提供一种半导体封装模组500，包括电子元器件510、附着在所述电子元器件510上的磁性薄膜520、以及附着在所述磁性薄膜520上的金属屏蔽层530。所述磁性薄膜520的结构与上述的磁性薄膜100和磁性薄膜200的结构基本相同，区别仅在于所述磁性薄膜520的基底层不同，其为塑封材料层，厚度为5μm-500μm，所述塑封材料层中含有聚合物树脂、无机填料(例如二氧化硅)、以及其他的功能组分。即，交替排布多个磁性层和所述多个介质层是直接沉积在所述塑封材料层上。所述塑封材料层既用以封装所述电子元器件510，又充当磁性薄膜520的基底。所述电子元器件510可为集成电路、集成电路的器件、或芯片(例如系统级封装的芯片)等。所述磁性薄膜520吸收所述半导体封装模组500内部相互串扰的噪声，所述金属屏蔽层530用于避免半导体封装模组500中的电磁波辐射到外部，通过所述磁性薄膜520和所述金属屏蔽层530可有效解决半导体封装模组500的噪声干扰问题。
可以理解的，交替排布多个磁性层和多个介质层的复合叠层与所述基底(塑封材料层)之间还可以选择性地设置结合层(图未示)以提高二者之间的连接强度。
可以理解的，由于金属屏蔽层530的材质原因容易发生氧化，所述金属屏蔽层530上还可包覆有一保护层(图未示)以防止金属屏蔽层530氧化。
本申请还提供一种电子设备(图未示)，其包括上述的半导体封装模组500。例如所述电子设备还包括壳体，所述半导体封装模组500位于所述壳体中。或者，所述电子设备包括电路板，所述半导体封装模组500设置于所述电路板上。
请参阅图5，本申请还提供一种磁性薄膜的制备方法，包括：
提供基底；
在所述基底的一表面形成复合层，所述复合层包括多个磁性层和多个介质层，所述多个磁性层和所述多个介质层为交替排布，即交替循环溅射磁性层和介质层；每一个磁性层的厚度为2nm-100nm；每一个介质层厚度为2nm-10nm；所述多个磁性层和所述多个介质层的总厚度为50nm-10μm；
溅射形成所述复合层的过程中，所述复合层中的内应力释放导致所述复合层形成非周期性分布的裂纹。
所述基底可选择厚度为5μm-50μm的基底，且玻璃转化温度为25℃-100℃，熔点大于100℃。所述的基底为高分子材料，优选的，所述基底的材质可为聚对苯二甲酸乙二醇酯(PET)、聚甲基丙烯酸甲酯(PMMA)、聚丁二烯-苯乙烯(PBS)、聚苯硫醚(PPS)、丙烯腈-丁二烯-苯乙烯塑料(ABS)、聚对苯二甲酸乙二醇酯-1,4-环己烷二甲醇酯(PETG)、聚苯乙烯(PS)中的一种。所述基底还可为塑封材料层。溅射前，还需对所述基底进行清洁处理，以去除其表面的杂质和脏污。
所述磁性层的成份为铁磁性金属或铁磁性合金，例如Fe、Co、Ni、FeSiAl合金、FeNi合金、FeCo合金、FeCoNi合金、FeCr合金、FeCoCr合金、FeB合金。
所述介质层的成份为绝缘的氧化物、氮化物、氟化物中的至少一种，优选为二氧化硅、氧化铝、氧化镁、氮化铝、氮化硅、氟化镁、氟化钙中的至少一种。
溅射选用具有直流和射频多靶位溅射功能、并具有自动程序控制及往复多层溅射功能的磁控溅射镀膜设备作为制备设备。
每一个磁性层采用直流溅射方式，设置溅射气压0.1Pa-10Pa，调节溅射功率与靶基距使溅射速率达到0.1nm/s-2nm/s，每层溅射时间5s-100s。
每一个介质层采用射频溅射方式，设置溅射气压0.1Pa-10Pa，调节溅射功率与靶基距使溅射速率达到0.05nm/s-0.1nm/s，每层溅射时间5s-500s。
所述制备方法还包括在每相邻的磁性层与介质层之间形成过渡层，所述过渡层含有所述磁性层中的铁磁性金属或铁磁性合金和所述介质层中的绝缘材料。例如，按照介质层、过渡层、磁性层、过渡层的顺序依次交替循环溅射，直至层数和厚度达到设定值。所述过渡层的厚度小于等于10nm。所述过渡层中，所述磁性合金材料的体积占比在20％到80％之间，优选地在50％-80％之间。
过渡层采用直流和射频共溅射的方式，设置溅射气压0.2Pa-2.0Pa，调节直流与射频溅射之间的溅射速率比介于0.2-5之间，每层溅射时间小于等于50s。
另外，为了使溅射过程中，薄膜能够累积足够的内应力产生裂纹，在溅射时应使溅射材料以较高的溅射速率进行溅射；较低的溅射效率，成膜质量好，内应力积累不足难以产生裂纹；溅射效率太高，多层结构容易破坏，甚至粉化脱落。
此外，磁控溅射过程中，溅射气压对于溅射速率及成膜质量至关重要。溅射气压过低，靶材难以启辉或者辉光不稳定，溅射效果不佳；溅射气压过高，溅射出来的靶材粒子与气体碰撞机会增多，影响成膜附着力，并对磁性能造成影响。
本申请具有以下优点和有益效果：本申请的磁性薄膜的磁导率高，相对于传统吸波材料高出10-30倍，可达到200-600；而相较于其它工艺制备的磁性薄膜，其电阻率高10-1000倍，极大增加了趋肤深度、提升了对电磁波的阻抗匹配性；并且在厚度达到微米级时仍能够保持高磁导率。因而，本申请的磁性薄膜在保持极薄的厚度下，展现出优异的微波吸收性能，只需要传统吸波材料1/10以下的厚度即可获得相当的、甚至更好的吸波性能，突破了现有吸波材料的厚度和性能瓶颈；也突破了磁性薄膜材料因电导率高导致阻抗匹配性能差及吸收性能弱的瓶颈。本申请的磁性薄膜作为吸波材料在电子元器件、无线通信及雷达吸波隐身等领域具有广阔的应用前景，特别适用于极薄厚度及可穿戴场景下的电磁干扰与防治。
本申请的磁性薄膜的制备方法相对于现有的光刻法等制备图案化的方式，具有便捷、低成本的优势，并且可以对磁导率、磁共振频率和电阻率进行调节。
下面通过具体实施例对本申请实施例技术方案进行进一步的说明。
实施例1
将用无水乙醇清洗并干燥后的20μm厚的PET(Polyethylene terephthalate，聚对苯二甲酸乙二醇酯)材质的基底固定在磁控溅射样品托盘上，抽真空，待磁控溅射腔室本底真空度达到10 -4Pa时，设置工艺参数：氩气流量为40sccm，溅射气压为0.15Pa，托盘转速20r/min，FeSiAl采用直流溅射，溅射效率0.5nm/s，SiO 2采用射频溅射，溅射效率为0.05nm/s。按照FeSiAl磁性合金层、共溅射过渡层、SiO 2介质层、共溅射层的顺序依次交替溅射，每层FeSiAl磁性合金层厚度6nm，每层SiO 2介质层厚度2nm，每层共溅射过渡层厚度5nm，溅射完100个循环时，溅射结束，得到FeSiAl/SiO 2多层磁性薄膜的样品。扫描电子显微镜表征结果表明该样品总厚度1.8μm，具有较好的分层结构，采用单端口短路波导法测试其磁导率在1.5GHz处磁导率虚部达到250，采用四探针电阻仪测试其方阻并计算其电导率为5×10 6S/m。
图6为实施例1的磁性薄膜的样品的扫描电镜图断面图。图7为实施例1得到的磁性薄膜进行微带线测试得到吸收率曲线，可见，实施例1的磁性薄膜的吸波性能在1-2GHz其对电磁波的吸收率达90％以上，展示出优异的微波吸收性能。
实施例2
将用无水乙醇清洗并干燥后的20μm厚的PET材质的基底固定在磁控溅射样品托盘上，抽真空，待磁控溅射腔室本底真空度达到10 -4Pa时，设置工艺参数：氩气流量为40sccm，溅射气压为0.2Pa，托盘转速20r/min，FeNi采用直流溅射，溅射效率0.3nm/s，SiO 2采用射频溅射，溅射效率为0.05nm/s。按照FeNi磁性合金层、SiO 2介质层的顺序依次交替溅射，每层FeNi磁性合金层厚度5nm，每层SiO 2介质层厚度2nm，溅射完100个循环时，溅射结束，得到FeNi/SiO 2多层磁性薄膜样品。扫描电子显微镜表征结果表明该样品总厚度0.7μm，具有较好的分层结构，采用四探针电阻仪测试其方阻并计算其电导率为3×10 5S/m。
采用单端口短路波导法测试实施例2的磁性薄膜，如图8所示，实施例2的磁性薄膜的磁导率在0.6GHz处磁导率虚部达到270。
实施例3
将用无水乙醇清洗并干燥后的20μm厚的PET材质的基底固定在磁控溅射样品托盘上，抽真空，待磁控溅射腔室本底真空度达到10 -4Pa时，设置工艺参数：氩气流量为40sccm，溅射气压为0.2Pa，托盘转速20r/min，FeNi采用直流溅射，溅射效率0.3nm/s，SiO 2采用射频溅射，溅射效率为0.05nm/s。按照FeNi磁性合金层、SiO 2介质层的顺序依次交替溅射，每层FeNi磁性合金层厚度15nm，每层SiO 2介质层厚度2nm，溅射完40个循环时，溅射结束，得到FeNi/SiO 2多层磁性薄膜样品。扫描电子显微镜表征结果表明该样品总厚度0.7μm，具有较好的分层结构，采用四探针电阻仪测试其方阻并计算其电导率为1.4×10 5S/m。
采用单端口短路波导法测试实施例3的磁性薄膜，如图9所示，实施例3的磁性薄膜的磁导率在0.7GHz处磁导率虚部达到630。
实施例4
将用无水乙醇清洗并干燥后的20μm厚的PET材质的基底固定在磁控溅射样品托盘上，抽真空，待磁控溅射腔室本底真空度达到10 -4Pa时，设置工艺参数：氩气流量为40sccm，溅射气压为0.2Pa，托盘转速20r/min，FeNi采用直流溅射，溅射效率0.3nm/s，SiO 2采用射频溅射，溅射效率为0.05nm/s。按照FeNi磁性合金层、SiO 2介质层的顺序依次交替溅射，每层FeNi磁性合金层厚度15nm，每层SiO 2介质层厚度2.5nm，溅射完70个循环时，溅射结束，得到FeNi/SiO 2多层磁性薄膜样品。
扫描电子显微镜表征结果表明该样品总厚度1.2μm，具有较好的分层结构，采用单端口短路波导法测试其磁导率在1.2GHz处磁导率虚部达到180，采用四探针电阻仪测试其方阻并计算其电导率为3×10 5S/m，具有半贯穿型纹路。
实施例5
将用无水乙醇清洗并干燥后的20μm厚的PET材质的基底固定在磁控溅射样品托盘上，抽真空，待磁控溅射腔室本底真空度达到10 -4Pa时，设置工艺参数：氩气流量为40sccm，溅射气压为0.2Pa，托盘转速20r/min，FeNi采用直流溅射，溅射效率0.3nm/s，SiO 2采用射频溅射，溅射效率为0.05nm/s。按照FeNi磁性合金层、SiO 2介质层的顺序依次交替溅射，每层FeNi磁性合金层厚度15nm，每层SiO 2介质层厚度3nm，溅射完70个循环时，溅射结束，得到FeNi/SiO 2多层磁性薄膜样品。扫描电子显微镜表征结果表明该样品总厚度1.1μm，具有较好的分层结构，采用单端口短路波导法测试其磁导率在0.7GHz处磁导率虚部达到307，采用四探针电阻仪测试其方阻并计算其电导率为3×10 6S/m。
采用振动样品磁强计测试实施例5的磁性薄膜，如图10所示的静磁性能曲线，发现其矫顽力仅0.6Oe展示出极好的磁性性能。
实施例6
将用无水乙醇清洗并干燥后的12.5μm厚的PET材质的基底固定在磁控溅射样品托盘上，抽真空，待磁控溅射腔室本底真空度达到10 -4Pa时，设置工艺参数：氩气流量为40sccm，溅射气压为0.35Pa，托盘转速20r/min，FeNi采用直流溅射，溅射效率0.3nm/s，SiO 2采用射频溅射，溅射效率为0.05nm/s。按照FeNi磁性合金层、SiO 2介质层的顺序依次交替溅射，每层FeNi磁性合金层厚度15nm，每层SiO 2介质层厚度3nm，溅射完120个循环时，溅射结束，得到FeNi/SiO 2多层磁性薄膜样品。扫描电子显微镜表征结果表明该样品总厚度2.1μm，具有较好的分层结构，采用单端口短路波导法测试其磁导率在1.05GHz处磁导率虚部达到215，采用四探针电阻仪测试其方阻并计算其电导率为500S/m，具有贯穿的裂纹结构。
图11为实施例6的磁性薄膜的样品的XRD(X-ray diffraction，X射线衍射)图谱，可以检测到基底PET和磁性合金层FeNi 3的特征峰。通过XRD衍射图谱，计算平均晶粒尺寸为5nm。
实施例7
将用无水乙醇清洗并干燥后的12.5μm厚的PET材质的基底固定在磁控溅射样品托盘上，抽真空，待磁控溅射腔室本底真空度达到10 -4Pa时，设置工艺参数：氩气流量为40sccm，溅射气压为0.35Pa，托盘转速20r/min，FeNi采用直流溅射，溅射效率0.42nm/s，SiO 2采用射频溅射，溅射效率为0.063nm/s。按照FeNi磁性合金层、SiO 2介质层的顺序依次交替溅射，每层FeNi磁性合金层厚度15nm，每层SiO 2介质层厚度3nm，溅射完120个循环时，溅射结束，得到FeNi/SiO 2多层磁性薄膜样品。扫描电子显微镜表征结果表明该样品总厚度2.1μm，具有较好的分层结构，采用单端口短路波导法测试其磁导率在1.35GHz处磁导率虚部达到350，采用四探针电阻仪测试其方阻并计算其电导率为50S/m。
图12为实施例7的磁性薄膜的样品的显微镜透射照片。从图12可以看到贯穿型的裂纹，裂纹围成不规则的多边形单元，多边形单元的面积为0.001mm 2-0.3mm 2。
实施例8
将用无水乙醇清洗并干燥后的12.5μm厚的PET材质的基底固定在磁控溅射样品托盘上，抽真空，待磁控溅射腔室本底真空度达到10 -4Pa时，设置工艺参数：氩气流量为40sccm， 溅射气压为0.35Pa，托盘转速20r/min，FeNi采用直流溅射，溅射效率0.42nm/s，SiO 2采用射频溅射，溅射效率为0.063nm/s。按照FeNi磁性合金层、共溅射过渡层、SiO 2介质层、共溅射过渡层的顺序依次交替溅射，每层FeNi磁性合金层厚度9.5nm，每层共溅射过渡层3.5nm，每层SiO 2介质层厚度2nm，溅射完120个循环时，溅射结束，得到FeNi/SiO 2多层磁性薄膜样品。扫描电子显微镜表征结果表明该样品总厚度2.1μm，具有较好的分层结构，采用单端口短路波导法测试其磁导率在1.28GHz处磁导率虚部达到290，采用四探针电阻仪测试其方阻并计算其电导率为1000S/m。
图13为实施例8的磁性薄膜的样品的显微镜反射照片。从图13可以看到贯穿型的裂纹，裂纹为不规则的多边形，裂纹宽度约0.1μm。
实施例9
将塑封好的芯片模组固定在磁控溅射样品托盘上，抽真空，待磁控溅射腔室本底真空度达到10 -4Pa时，首先在芯片模组的塑封材料层表面溅射一层结合层，然后设置工艺参数：氩气流量为40sccm，溅射气压为0.35Pa，托盘转速20r/min，FeNi采用直流溅射，溅射效率0.42nm/s，SiO 2采用射频溅射，溅射效率为0.063nm/s。按照FeNi磁性合金层、共溅射过渡层、SiO 2介质层、共溅射过渡层的顺序依次交替溅射，每层FeNi磁性合金层厚度9.5nm，每层共溅射过渡层3.5nm，每层SiO 2介质层厚度2nm，溅射完120个循环时，可在结合层表面生长出软磁薄膜层，得到FeNi/SiO 2多层磁性薄膜。在FeNi/SiO 2多层磁性薄膜的表面继续溅射金属屏蔽层和保护层。
需要说明的是，以上仅为本申请的具体实施方式，但本申请的保护范围并不局限于此，任何熟悉本技术领域的技术人员在本申请揭露的技术范围内，可轻易想到变化或替换，都应涵盖在本申请的保护范围之内；在不冲突的情况下，本申请的实施方式及实施方式中的特征可以相互组合。因此，本申请的保护范围应以权利要求的保护范围为准。

Claims (26)

  1. 一种磁性薄膜，其特征在于，包括：
    基底；
    位于所述基底一侧的复合层，所述复合层包括层叠的多个磁性层和多个介质层，所述多个磁性层和所述多个介质层在所述基底一侧交替排布；
    每一个磁性层的厚度为2nm-100nm；每一个介质层的厚度为2nm-10nm；所述复合层的厚度为50nm-10μm；所述复合层包括多条裂纹，所述多条裂纹非周期性分布，至少部分所述多条裂纹沿垂直所述复合层的层叠方向的横截面的延伸方向不同，至少部分所述多条裂纹沿垂直所述复合层的层叠方向的横截面非直线延伸。
  2. 根据权利要求1所述的磁性薄膜，其特征在于，所述多条裂纹为溅射形成所述复合层的过程中，所述复合层中的内应力释放导致。
  3. 根据权利要求1所述的磁性薄膜，其特征在于，所述裂纹将所述复合层分割成若干区域。
  4. 根据权利要求3所述的磁性薄膜，其特征在于，每一个所述区域沿所述横截面方向的面积为0.001mm 2-0.3mm 2。
  5. 根据权利要求1至4中任一项所述的磁性薄膜，其特征在于，所述多条裂纹包括以下中的至少一种：沿所述复合层各层的堆叠方向，延伸深度等于所述复合层的堆叠高度的裂纹；以及沿所述复合层各层的堆叠方向，延伸深度小于所述复合层的堆叠高度的裂纹。
  6. 根据权利要求1至5中任一项所述的磁性薄膜，其特征在于，每一条所述裂纹的开口宽度小于2μm。
  7. 根据权利要求1至6中任一项所述的磁性薄膜，其特征在于，每一个所述磁性层的厚度为5nm-40nm。
  8. 根据权利要求1至7中任一项所述的磁性薄膜，其特征在于，每一个所述磁性层的材质为铁磁性金属或铁磁性合金。
  9. 根据权利要求1至8中任一项所述的磁性薄膜，其特征在于，所述介质层的成份为绝缘的氧化物、氮化物或氟化物中的至少一种。
  10. 根据权利要求1至9中任一项所述的磁性薄膜，其特征在于，所述复合层还包括多个过渡层，每相邻的所述磁性层与介质层之间形成有过渡层，所述过渡层的厚度小于等于10nm；所述过渡层含有所述磁性层中的磁性材料和所述介质层中的绝缘材料。
  11. 根据权利要求10所述的磁性薄膜，其特征在于，所述磁性材料在所述过渡层中的体积占比在20％到80％之间。
  12. 根据权利要求1所述的磁性薄膜，其特征在于，所述多个磁性层和多个介质层的总层数大于50层，总厚度大于300nm。
  13. 根据权利要求12所述的磁性薄膜，其特征在于，所述复合层的厚度为1μm-10μm。
  14. 根据权利要求1至13中任一项所述的磁性薄膜，其特征在于，所述基底的厚度为5μm-50μm，玻璃转化温度为25℃-100℃，熔点大于100℃。
  15. 根据权利要求14所述的磁性薄膜，其特征在于，所述基底的材质为聚对苯二甲酸乙二醇酯、聚甲基丙烯酸甲酯、聚丁二烯-苯乙烯、聚苯硫醚、丙烯腈-丁二烯-苯乙烯塑料、聚 对苯二甲酸乙二醇酯-1,4-环己烷二甲醇酯、聚苯乙烯中的一种。
  16. 根据权利要求1至13中任一项所述的磁性薄膜，其特征在于，所述基底为塑封材料层，厚度为5μm-500μm。
  17. 一种半导体封装模组，其特征在于，包括电子元器件、附着在所述电子元器件上的如权利要求16所述的磁性薄膜、以及附着在所述磁性薄膜上的金属屏蔽层。
  18. 一种电子设备，其特征在于，包括电路板和位于所述电路板上的如权利要求17所述的半导体封装模组。
  19. 一种电子设备，其特征在于，包括壳体位于所述壳体中的如权利要求17所述的半导体封装模组。
  20. 一种电子设备，其特征在于，包括辐射电磁波的噪声源和权利要求1至15中任一项所述的磁性薄膜，所述磁性薄膜贴附在噪声源上或者设置在噪声源传播噪声的路径上。
  21. 根据权利要求20所述的电子设备，其特征在于，所述电子设备包括金属材质的中框和金属件，所述中框和所述金属件配合构成腔体，所述腔体中设置有所述噪声源，所述腔体外设置有信号发射器，所述磁性薄膜位于所述腔体中。
  22. 一种磁性薄膜的制备方法，其特征在于，包括：
    提供基底；
    采用溅射法，在所述基底的一侧形成复合层，所述复合层包括多个磁性层和多个介质层，所述多个磁性层和所述多个介质层在所述基底的一侧为交替排布；
    每一个磁性层的厚度为2nm-100nm；每一个介质层厚度为2nm-10nm；所述复合层的厚度为50nm-10μm；
    溅射形成所述复合层的过程中，所述复合层中的内应力释放导致所述复合层中形成非周期性分布的多条裂纹，至少部分所述多条裂纹沿垂直所述复合层的层叠方向的横截面的延伸方向不同，至少部分所述多条裂纹沿垂直所述复合层的层叠方向的横截面非直线延伸。
  23. 根据权利要求22所述的磁性薄膜的制备方法，其特征在于，每一个磁性层采用直流溅射方式，设置溅射气压为0.1Pa-10.0Pa，溅射速率为0.1nm/s-2nm/s，每层溅射时间为5s-100s。
  24. 根据权利要求22所述的磁性薄膜的制备方法，其特征在于，每一个介质层采用射频溅射方式，设置溅射气压为0.1Pa-10.0Pa，溅射速率为0.05nm/s-0.1nm/s，每层溅射时间为5s-500s。
  25. 根据权利要求22所述的磁性薄膜的制备方法，其特征在于，所述制备方法还包括在每相邻的磁性层与介质层之间形成过渡层，所述过渡层含有所述磁性层中的磁性材料和所述介质层中的绝缘材料，所述过渡层的厚度为小于等于10nm。
  26. 根据权利要求25所述的磁性薄膜的制备方法，其特征在于，所述过渡层采用直流和射频共溅射的方式，设置溅射气压为0.1Pa-10.0Pa，调节直流与射频溅射之间的溅射速率比介于0.2-5之间，每层溅射时间小于等于50s。
PCT/CN2022/085002 2021-05-27 2022-04-02 磁性薄膜及其制备方法、半导体封装模组和电子设备 WO2022247465A1 (zh)

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003338409A (ja) * 2002-05-22 2003-11-28 Taiyo Yuden Co Ltd 積層磁性薄膜及びその製造方法
CN1750184A (zh) * 2004-09-17 2006-03-22 太阳诱电株式会社 叠层磁性薄膜及其制造方法
JP2010092989A (ja) * 2008-10-06 2010-04-22 Fuji Electric Systems Co Ltd 圧粉磁心およびその製造方法
CN109887706A (zh) * 2019-04-04 2019-06-14 东北大学 一种磁性纳米颗粒复合膜及其制备方法
CN112216469A (zh) * 2019-07-12 2021-01-12 株式会社村田制作所 磁性层叠体和含其的磁性结构体、含该层叠体或结构体的电子部件和磁性层叠体的制造方法

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003338409A (ja) * 2002-05-22 2003-11-28 Taiyo Yuden Co Ltd 積層磁性薄膜及びその製造方法
CN1750184A (zh) * 2004-09-17 2006-03-22 太阳诱电株式会社 叠层磁性薄膜及其制造方法
JP2010092989A (ja) * 2008-10-06 2010-04-22 Fuji Electric Systems Co Ltd 圧粉磁心およびその製造方法
CN109887706A (zh) * 2019-04-04 2019-06-14 东北大学 一种磁性纳米颗粒复合膜及其制备方法
CN112216469A (zh) * 2019-07-12 2021-01-12 株式会社村田制作所 磁性层叠体和含其的磁性结构体、含该层叠体或结构体的电子部件和磁性层叠体的制造方法

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