Metallic magnetic flexible composite inductor conductor and method of making same

Abstract

A metal magnetic flexible composite inductor conductor and a preparation method thereof; the preparation method of the metal magnetic flexible composite inductor conductor comprises the following steps: S1: taking metal and magnetic material; the magnetic induction intensity of the magnetic material is greater than or equal to 1.6 T; S2: continuously attaching the metal to the magnetic material to obtain a conductive and magnetically conductive composite conductor; S3: cutting the conductive and magnetically conductive composite conductor by using a femtosecond laser processing technology to obtain a spiral flexible composite inductor conductor. The flexible composite inductor conductor prepared by the scheme can obtain a larger self-inductance value under the same size, can effectively suppress leakage magnetic flux, reduce leakage magnetic coupling to the outside world and electromagnetic interference, and can realize a more compact spiral inductor layout by reducing the number of turns or reducing the coil geometric size, thereby solving the problem that high inductance density and low power consumption cannot be simultaneously achieved in the traditional inductor conductor.

Description

Technical Field

[0001] This invention relates to the field of inductors, and more particularly to a flexible composite inductor with metallic magnetic properties and its preparation method. Background Technology

[0002] An inductor is a component that converts electrical energy into magnetic energy and stores it. The structure of an inductor is similar to a transformer, but it has only one winding. An inductor has a certain inductance, which only impedes changes in current. If no current is flowing through the inductor, it will attempt to impede the current flow when the circuit is closed; if current is flowing through the inductor, it will attempt to maintain a constant current when the circuit is open.

[0003] Traditional inductors typically use copper, which has excellent conductivity but lacks magnetism and high permeability. While using soft magnetic alloys can reduce magnetic leakage, their conductivity is inferior to copper, resulting in higher resistance and power consumption. Therefore, inductors face the following design challenges: pure copper offers excellent conductivity but extremely low permeability, leading to weak magnetic field confinement and significant magnetic leakage; soft magnetic alloys, with their high permeability, effectively suppress magnetic leakage, but their much higher resistivity causes significant Joule heat loss. A balance between these two factors is difficult to achieve. Summary of the Invention

[0004] The purpose of this invention is to propose a method for preparing a flexible composite inductor with metallic magnetic properties. The method involves mixing a metal with saturated magnetic powder to form a magnetic mixture and then forming a spiral strip. This method can achieve a larger self-inductance value within the same size, effectively suppressing leakage magnetic flux, reducing leakage magnetic coupling and electromagnetic interference to the outside world, and achieving a more compact spiral inductor layout by reducing the number of turns or shrinking the coil geometry.

[0005] The present invention also proposes a metal magnetic flexible composite inductor conductor, which is prepared by the above-mentioned method for preparing a metal magnetic flexible composite inductor conductor.

[0006] To achieve this objective, the present invention adopts the following technical solution: A method for preparing a flexible composite inductor with metallic magnetic properties includes the following steps: S1: Take a metallic object and a magnetic object; the magnetic induction intensity of the magnetic object is ≥1.6T; S2: Continuously attaching a metal object to a magnetic object to obtain a conductive and magnetically permeable composite conductor; S3: The conductive and magnetic composite conductor is cut using femtosecond laser processing technology to obtain a helical flexible composite inductor conductor.

[0007] A method for preparing a flexible composite inductor with metallic magnetic properties includes the following steps: S1: Take a metal object and a saturated magnetic powder; the magnetic induction intensity of the saturated magnetic powder is ≥1.6T; S2: Mix the metal, saturated magnetic powder and binder evenly, with the mass ratio of metal to saturated magnetic powder being 1:(0.1~3), and the amount of binder added being 0~10wt% of the total mass of the metal and saturated magnetic powder, to obtain a magnetic mixture; pour the magnetic mixture into a spiral strip mold to form it, and sinter it at a low temperature under a protective atmosphere, with a sintering temperature of 100~200℃, to obtain a conductive and magnetic composite conductor; S3: The conductive and magnetic composite conductor is cut using femtosecond laser processing technology to obtain a helical flexible composite inductor conductor.

[0008] Optimally, in step S1, the metal is metal powder and / or liquid metal; the metal powder includes at least one of copper, silver, aluminum, gold, iron and nickel, or an alloy thereof; the particle size of the metal powder is less than 50 nm, and the particle size of the saturated magnetic powder is smaller than that of the metal powder. Liquid metals include at least one of elemental gallium, gallium-indium alloys, and gallium-indium-tin alloys.

[0009] Alternatively, during the low-temperature sintering process in step S2, a pressure of 10–100 MPa may be applied to the magnetic mixture.

[0010] Optimally, the saturated magnetic powder includes at least one of Fe-Co alloy powder, Fe-Ni alloy powder, Fe-Co-B alloy powder, Fe-Si-B-Nb-Cu alloy powder, and Fe-Co-Si-B alloy powder.

[0011] A method for preparing a flexible composite inductor with metallic magnetic properties includes the following steps: S1: Take a metallic object and a saturated soft magnetic tape; the magnetic induction intensity of the magnetic object is ≥1.6T; S2: Deposit metal on the surface of saturated flexible magnetic tape to form a continuous conductive metal layer on the surface of the saturated flexible magnetic tape, so as to obtain a layered conductive and magnetic composite conductor. S3: Femtosecond laser processing technology is used to cut the layered conductive and magnetic composite conductor into a spiral shape to obtain a spiral flexible composite inductor conductor.

[0012] Optimally, in step S2, a single or multiple layers of conductive metal are deposited on the saturated flexible magnetic tape, wherein the thickness of the saturated flexible magnetic tape is 10–30 μm and the thickness of the conductive metal is 1–10 μm.

[0013] Alternatively, in step S1, the alloy strip is selected from Fe-Si-B-Nb-Cu alloy, Fe-Zr-B alloy, Fe-Co-B alloy, or Fe-Co-Si-B alloy.

[0014] Alternatively, in step S2, the metal is deposited on the surface of the saturated flexible magnetic material by one of physical vapor deposition, sputtering deposition, vacuum evaporation, laser-induced deposition, electroplating, or electroless plating.

[0015] A flexible composite inductor with metallic magnetic properties, prepared by the above-described method for preparing a flexible composite inductor with metallic magnetic properties.

[0016] Compared with the prior art, one of the above technical solutions has the following beneficial effects: This solution provides a method for preparing a flexible composite inductor conductor with metallic magnetic properties. The method involves mixing a metal with saturated magnetic powder to form a magnetic mixture, which is then fabricated into a spiral strip. This method can achieve a larger self-inductance value within the same size, effectively suppressing leakage flux, reducing leakage flux coupling and electromagnetic interference to the outside world, and achieving a more compact spiral inductor layout by reducing the number of turns or shrinking the coil geometry. This solves the problem that traditional inductors cannot simultaneously achieve high inductance density and low power consumption. Attached Figure Description

[0017] Figure 1 This is a schematic flowchart of the preparation method of the metal magnetic flexible composite inductor conductor in Example 1; Figure 2 This is a schematic flowchart of the preparation method of the metal magnetic flexible composite inductor conductor in Example 2; Figure 3 This is a schematic diagram of the structure of one embodiment of the magnetic mixture; Figure 4 This is a schematic diagram of the structure when tweezers are used to pick up a spiral-shaped flexible composite inductor conductor; Figure 5 This is a schematic diagram of one embodiment of a spiral-shaped flexible composite inductor.

[0018] in: 1. Conductive and magnetic composite conductor; 2. Femtosecond laser; 3. Flexible composite inductor; 4. Tweezers; 11. Metal; 12. Saturated magnetic powder; 13. Soft magnetic tape; 14. Metal conductive layer. Detailed Implementation

[0019] To facilitate understanding of the present invention, a more comprehensive description is provided below. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of the present invention. Where specific techniques or conditions are not specified in the embodiments, they are performed in accordance with techniques or conditions described in the literature in the art or according to product instructions. Reagents or instruments used, unless otherwise specified, are all conventional products that can be obtained commercially.

[0020] like Figure 1-5 A method for preparing a flexible composite inductor with metallic magnetic properties includes the following steps: S1: Take a metallic object and a magnetic object; the magnetic induction intensity of the magnetic object is ≥1.6T; S2: Continuously attaching a metal object to a magnetic object to obtain a conductive and magnetically permeable composite conductor; S3: The conductive and magnetic composite conductor is cut using femtosecond laser processing technology to obtain a helical flexible composite inductor conductor.

[0021] This solution employs femtosecond laser processing technology. The laser energy of the femtosecond laser is deposited in an extremely short time, avoiding melting, recasting, and excessive thermal stress concentration caused by thermal diffusion. This allows for high-precision processing of helical structures while effectively preventing crystallization and magnetic property degradation of soft magnetic materials. The femtosecond laser parameters are selected from a range of wavelengths of 400–600 nm, average power of 200–500 mW, repetition frequency of 50–200 kHz, and scanning speed of 0.2–1.0 mm / s, to achieve precise cutting and smooth edge formation without damaging the alloy strip structure.

[0022] This solution provides a method for preparing a flexible composite inductor conductor with metallic magnetic properties. It involves mixing a metal with saturated magnetic powder and forming a spiral strip, which can achieve a larger self-inductance value within the same size. This method can effectively suppress leakage magnetic flux, reduce leakage magnetic coupling and electromagnetic interference to the outside world, and achieve a more compact spiral inductor layout by reducing the number of turns or shrinking the coil geometry. This solves the problem that traditional inductors cannot simultaneously achieve high inductance density and low power consumption.

[0023] A method for preparing a flexible composite inductor with metallic magnetic properties includes the following steps: S1: Take a metal object and a saturated magnetic powder; the magnetic induction intensity of the saturated magnetic powder is ≥1.6T; The conductor portion of the flexible composite inductor is formed by a combination of a metallic phase and a soft magnetic phase. The metallic phase is formed after subsequent sintering and provides the main conductive path. The soft magnetic phase is used to improve the magnetic permeability of the conductor and reduce leakage flux, thereby enhancing the overall performance of the flexible composite inductor and reducing electromagnetic losses. S2: Mix the metal, saturated magnetic powder and binder evenly, with the mass ratio of metal to saturated magnetic powder being 1:(0.1~3), and the amount of binder added being 0~10wt% of the total mass of the metal and saturated magnetic powder, to obtain a magnetic mixture; pour the magnetic mixture into a spiral strip mold to form it, and sinter it at a low temperature under a protective atmosphere, with a sintering temperature of 100~200℃, to obtain a conductive and magnetic composite conductor; The saturated magnetic powder used in this scheme has a magnetic induction intensity ≥1.6T. After being mixed with metal, it undergoes low-temperature sintering, requiring a sintering temperature of 100–200℃. This allows the metal phase and the soft magnetic phase to form a stable interface, achieving synergy between electrical and magnetic permeability. Excessive temperature may damage the interface, preventing the synergy between electrical and magnetic permeability. The metallic material in the flexible composite inductor can increase the conductivity of the inductor conductor and reduce power consumption.

[0024] In step S2, the mold has a spiral-shaped groove. When the magnetic mixture is poured into the mold, a spiral-shaped structure is formed, such as... Figure 5 The flexible composite inductor is evenly coiled several times from the center outwards, thus cutting it into an approximately circular planar spiral structure with a slit between adjacent spirals.

[0025] When the mass ratio of metal to saturated magnetic powder is 1:(0.1~3), the resulting helical flexible composite inductor can achieve a balance between conductivity, magnetic properties and processing stability. When the mass ratio of the metal phase is too large, the magnetic phase in the composite inductor is insufficient to form an effective magnetic flux path, making it difficult to significantly improve the inductance value. When the mass ratio of the soft magnetic phase is too large, the metal phase is difficult to form a continuous conductive network, resulting in a decrease in conductivity and structural stability.

[0026] The amount of adhesive added is 0 to 10 wt% of the total mass of the metal and the saturated magnetic powder, and the amount added depends on the metal; for example, it can be 0% when liquid metal is selected; the amount added can also be 0.1 wt%, 0.2 wt%, 0.3 wt%, or 1 wt%, 2 wt%, 3 wt%, etc.; the adhesive can be selected as a known organic adhesive or inorganic adhesive as needed. Organic adhesives can be: acrylic resins such as polymethyl methacrylate and polybutyl methacrylate; or various organic adhesives such as waxes, paraffin waxes, higher fatty acids (such as stearic acid), higher alcohols, higher fatty acid esters, and higher fatty acid amides; or polyesters such as polyvinyl chloride, polyvinylidene chloride, polyamide, polyethylene terephthalate, and polybutylene terephthalate; or resins such as polyether, polyvinyl alcohol, polyvinylpyrrolidone, or their copolymers; or polyolefins such as polyethylene, polypropylene, and ethylene-vinyl acetate copolymer; and styrene resins such as polystyrene.

[0027] Inorganic adhesives can be: silicate adhesives such as sodium silicate; or phosphate inorganic adhesives, phosphate adhesives such as copper oxide-phosphate glue; borate adhesives, sulfate adhesives; or clay inorganic adhesives such as SiO2, Al2O3 silicate mixtures, bentonite, kaolin, etc.; inorganic binders such as yttrium oxide, lanthanum oxide, cerium oxide, etc., and zirconium powder, etc.

[0028] In the final flexible composite inductor conductor, the spiral shape can reduce magnetic leakage, and the soft magnetic phase can reduce leakage magnetic coupling and electromagnetic interference to the outside world, which is convenient for high-density packaging and adjacent circuit layout. At the same time, the soft magnetic phase can increase the self-inductance of the inductor conductor, so that it can obtain a larger inductance value under the same size. Therefore, a more compact spiral inductor layout can be achieved by reducing the number of turns or shrinking the coil geometry.

[0029] The sintering atmosphere is a vacuum, hydrogen, a nitrogen-hydrogen mixture, or an atmosphere containing a gaseous reducing agent.

[0030] S3: The conductive and magnetic composite conductor is cut using femtosecond laser processing technology to obtain a helical flexible composite inductor conductor.

[0031] This solution provides a method for preparing a flexible composite inductor conductor with metallic magnetic properties. The method involves mixing a metal with saturated magnetic powder to form a magnetic mixture, which is then fabricated into a spiral strip. This method can achieve a larger self-inductance value within the same size, effectively suppressing leakage flux, reducing leakage flux coupling and electromagnetic interference to the outside world, and achieving a more compact spiral inductor layout by reducing the number of turns or shrinking the coil geometry. This solves the problem that traditional inductors cannot simultaneously achieve high inductance density and low power consumption.

[0032] Optimally, in step S1, the metal is metal powder and / or liquid metal; the metal powder includes at least one of copper, silver, aluminum, gold, iron and nickel, or an alloy thereof; the particle size of the metal powder is less than 50 nm, and the particle size of the saturated magnetic powder is smaller than that of the metal powder. Liquid metals include at least one of elemental gallium, gallium-indium alloys, and gallium-indium-tin alloys.

[0033] This method involves mechanically mixing a metallic material with saturated magnetic powder to achieve uniformity. The metallic material can be metal powder and / or liquid metal. In embodiments where the metallic material is metal powder, the metal powder is below 50 nm. On one hand, it possesses high specific surface area and high surface energy. Under applied pressure and reducing or inert atmosphere conditions, the metal particles undergo neck growth and surface diffusion at temperatures far below their melting points, thereby forming a continuous metal on the surface of the magnetic particles. On the other hand, its particle size is larger than that of saturated magnetic powder, such as… Figure 3 This allows the saturated magnetic powder to fill the gaps between the metal powders more fully, increasing the self-inductance of the inductor. In embodiments where the metal is liquid, the metal can be elemental gallium, gallium-indium alloy, or gallium-indium-tin alloy. The liquid metal, being a liquid, can fully fill the gaps between the saturated magnetic powders, thus forming a continuous metallic phase.

[0034] Alternatively, during the low-temperature sintering process in step S2, a pressure of 10–100 MPa may be applied to the magnetic mixture.

[0035] The pressure applied in this scheme promotes close contact between powder particles, reduces pore rearrangement, fills voids, and improves densification. Furthermore, this embodiment uses low-temperature sintering at 100–200°C, allowing the metallic phase and soft magnetic phase to form a stable interface. The pressure increases the contact area between powder particles, shortens the atomic diffusion distance, and thus reduces the activation energy required for diffusion. This enables the material to achieve high density at a lower temperature, while avoiding problems such as excessive grain growth that may occur with high-temperature sintering.

[0036] Optimally, the saturated magnetic powder includes at least one of Fe-Co alloy powder, Fe-Ni alloy powder, Fe-Co-B alloy powder, Fe-Si-B-Nb-Cu alloy powder, and Fe-Co-Si-B alloy powder.

[0037] This solution allows for the selection of one or more of the aforementioned alloy powders as saturated magnetic powders, as needed. Fe-Co alloy powder has the highest Bs, high Curie temperature, good high-temperature stability, and low vibration noise; Fe-Ni alloy powder has ultra-high initial permeability, low coercivity, and low hysteresis loss; In Fe-Co-B alloy powder, B enhances amorphous formation ability, refines grains, and reduces eddy current loss; Fe-Si-B-Nb-Cu alloy powder has the best overall performance, with a nanocrystalline structure achieving high saturation magnetic induction intensity, ultra-low high-frequency loss, and good temperature stability; In Fe-Co-Si-B alloy powder, Co enhances Bs, and Si / B synergistically improve resistivity and corrosion resistance, and after nanocrystallization, it combines high Bs with good high-frequency characteristics.

[0038] A method for preparing a flexible composite inductor with metallic magnetic properties includes the following steps: S1: Take a metallic object and a saturated soft magnetic tape; the magnetic induction intensity of the magnetic object is ≥1.6T; S2: Deposit metal on the surface of saturated flexible magnetic tape to form a continuous conductive metal layer on the surface of the saturated flexible magnetic tape, so as to obtain a layered conductive and magnetic composite conductor. A metallic conductive layer is deposited onto the surface of a saturated soft magnetic magnetic material using one of the following methods: physical vapor deposition, sputtering deposition, vacuum evaporation, laser-induced deposition, electroplating, or electroless plating. This forms a stable interface between the metallic and magnetic phases. The metallic phase provides the primary conductive path, while the soft magnetic phase enhances the conductor's permeability and reduces leakage flux, thereby improving the overall performance of the inductor and reducing electromagnetic losses. This achieves a synergistic effect between electrical and magnetic conductivity.

[0039] S3: Femtosecond laser processing technology is used to cut the layered conductive and magnetic composite conductor into a spiral shape to obtain a spiral flexible composite inductor conductor.

[0040] In this embodiment, the conductive and magnetically permeable composite conductor is layered. A femtosecond laser is used to cut the conductive and magnetically permeable composite conductor into a spiral shape, such as... Figure 2 The femtosecond laser begins cutting from the center of a conductive-magnetic composite conductor, spiraling outwards in several uniform turns to form an approximately circular planar helical structure, with slits between adjacent spirals; for example... Figure 4 The center of the conductive and magnetic composite conductor is held by tweezers, and the flexible composite inductor is spiral-shaped. Laser energy is deposited in a very short time, avoiding melting, recasting, and excessive concentration of thermal stress caused by thermal diffusion. Thus, while achieving high-precision spiral structure processing, it effectively avoids crystallization and magnetic property degradation of soft magnetic materials.

[0041] Optionally, the parameters of the femtosecond laser can be customized as needed to achieve precise cutting and smooth edge formation without damaging the alloy strip structure. In one embodiment, the femtosecond laser parameters are: wavelength 400–600 nm, average power 200–500 mW, repetition rate 50–200 kHz, and scanning speed in the range of 0.2–1.0 mm / s.

[0042] Optimally, in step S2, a single or multiple layers of conductive metal are deposited on the saturated flexible magnetic tape, wherein the thickness of the saturated flexible magnetic tape is 10–30 μm and the thickness of the conductive metal is 1–10 μm.

[0043] A single or multiple layers of conductive metal can be deposited on the saturated flexible magnetic tape. The thickness ratio of the conductive metal layer to the saturated flexible magnetic tape can be 1:(0.1~3). The resulting spiral flexible composite inductor can achieve a balance between conductivity, magnetic properties and processing stability. When the thickness of the conductive metal layer is too large, it is difficult for the composite inductor to significantly improve the inductance value. When the thickness of the saturated flexible magnetic tape is too large, it is easy to cause a decrease in conductivity and structural stability.

[0044] Alternatively, in step S1, the alloy strip is selected from Fe-Si-B-Nb-Cu alloy, Fe-Zr-B alloy, Fe-Co-B alloy, or Fe-Co-Si-B alloy.

[0045] The Fe-Si-B-Nb-Cu alloy exhibits the best overall performance. Its nanocrystalline structure achieves high saturation magnetic induction intensity, ultra-low high-frequency loss, and good temperature stability. In the Fe-Co-B alloy, B enhances the amorphous formation ability, refines the grains, and reduces eddy current loss. In the Fe-Co-Si-B alloy, Co increases Bs, and Si / B synergistically improve resistivity and corrosion resistance. After nanocrystallization, it combines high Bs with good high-frequency characteristics.

[0046] Alternatively, in step S2, the metal is deposited on the surface of the saturated flexible magnetic material by one of physical vapor deposition, sputtering deposition, vacuum evaporation, laser-induced deposition, electroplating, or electroless plating.

[0047] Physical vapor deposition (PVD) can be performed at lower temperatures, reducing the thermal impact on the magnetic properties of flexible magnetic materials, and forming a dense, non-porous structure in the metal, ensuring a stable interface between the metal and magnetic phases. During sputtering deposition, the magnetic bonding strength between the conductive metal layer and the flexible magnetic material is good, making it suitable for uniform coating on substrates with complex shapes. Laser-induced deposition (LAD) offers high laser energy density, allowing precise control over the deposition location and thickness of the conductive metal layer; it also features rapid heating, short high-temperature dwell time, and rapid cooling, minimizing the thermal impact on the flexible magnetic material. Electroplating offers stable processes and can achieve thicker conductive metal layer deposition; chemical plating is suitable for complex-shaped workpieces, producing a uniform conductive metal layer thickness.

[0048] A flexible composite inductor with metallic magnetic properties, prepared by the above-described method for preparing a flexible composite inductor with metallic magnetic properties.

[0049] Example 1: S1: Take a metal object and a saturated magnetic powder; the magnetic induction intensity of the saturated magnetic powder is 1.6T; the metal object is copper powder with a particle size of 40-50nm; the magnetic powder is Fe-Co-Si-B alloy powder; the binder is a silicate binder. S2: Mix the metal with saturated magnetic powder in a uniform manner, with a mass ratio of 1:1. Add 0.1 wt% of the total mass of the metal and saturated magnetic powder to obtain a magnetic mixture. Pour the magnetic mixture into a spiral strip mold and sinter it at a low temperature under a nitrogen-hydrogen mixture. The sintering temperature is 150℃, the sintering time is 60 min, the heating rate is 5℃ / min, and a pressure of 50 MPa is applied to the magnetic mixture during sintering to obtain a conductive and magnetic composite conductor. S3: Femtosecond laser processing technology is used to cut the conductive-magnetic composite conductor. The parameters of the femtosecond laser are: wavelength 450-500nm, average power 400mW, repetition frequency 150kHz, and scanning speed in the range of 0.8-1.0 mm / s; a helical flexible composite inductor conductor is obtained, such as... Figure 5 The flexible composite inductor has 6 turns N, a line width W of 50 μm, a line spacing d of 15 μm, and a thickness T of 20 μm.

[0050] Example 2: S1: Take a metal object and a saturated soft magnetic tape; the magnetic induction intensity of the magnetic object is 1.6T; the metal object is copper powder; the soft magnetic tape is Fe-Si-B-Nb-Cu alloy; S2: Deposit metal on both sides of the saturated flexible magnetic tape using physical vapor deposition to form a continuous conductive metal layer on the surface of the saturated flexible magnetic tape, thereby obtaining a layered conductive and magnetic composite conductor; the thickness of the saturated flexible magnetic tape is 20 μm, and the thickness of the conductive metal layer is 3 μm.

[0051] S3: Femtosecond laser processing technology is used to cut the layered conductive and magnetic composite conductor into a helical shape. The parameters of the femtosecond laser are: wavelength 450-500nm, average power 400mW, repetition frequency 150kHz, and scanning speed in the range of 0.8-1.0 mm / s; a helical flexible composite inductor is obtained. The flexible composite inductor has 6 turns N, a linewidth W of 50μm, a line spacing d of 15μm, and a thickness T of 20μm.

[0052] Performance tests were conducted on Examples 1 and 2: ① After bending radii of 10mm, 15mm, and 20mm for 1000 times, the inductor was tested using an impedance analyzer. The inductor was considered qualified if the rate of change was less than 5%. The results are shown in Table 1.

[0053] ② A zigzag copper inductor with 6 turns N, a line width W of 50 μm, a line spacing d of 15 μm, and a thickness T of 20 μm was selected as Comparative Example 1. The self-inductance of Examples 1, 2, and Comparative Example 1 was tested using an inductance tester, and the power consumption was tested using an inductance loss tester. The results are shown in Table 2 below.

[0054] illustrate: 1. Comparing Examples 1, 2, and Comparative Example 1, it can be seen that, under the same dimensions with the same linewidth (50 μm), line spacing (15 μm), and thickness (20 μm), Comparative Example 1 has a self-inductance of 40 nH and a power consumption of 5 mW; while Example 1, using the same material, has a self-inductance of 311 nH, which is 7 to 8 times that of Comparative Example 1; Example 1 has a power consumption of 2 mW, which is lower than that of Comparative Example 1. Similarly, Example 2 also has a higher self-inductance than Comparative Example 1, and lower power consumption. This shows that by mixing metal with saturated magnetic powder and forming a spiral strip, a larger self-inductance can be obtained under the same dimensions. Therefore, a more compact spiral inductor layout can be achieved by reducing the number of turns or shrinking the coil geometry, solving the problem that traditional inductors cannot simultaneously achieve high inductance density and low power consumption.

[0055] 2. As can be seen from the comparison between Example 1 and Example 2, the example uses saturated magnetic powder and metal mixed and then sintered at low temperature. The two achieve synergy of electrical conductivity and magnetic permeability, and are combined and processed into a spiral structure. The flexible composite inductor obtained by chemical mixing has a better self-inductance value than that of Example 2 which uses physical mixing.

[0056] Example 3: S1: Take a metal object and a saturated magnetic powder; the magnetic induction intensity of the saturated magnetic powder is 1.8T; the metal object is elemental gallium; the magnetic powder is Fe-Si-B-Nb-Cu alloy powder; S2: Mix the metal with saturated magnetic powder evenly, with a mass ratio of 1:3, to obtain a magnetic mixture; pour the magnetic mixture into a spiral strip mold to form a shape, and sinter it at a low temperature in a hydrogen atmosphere. The sintering temperature is 100℃, the sintering time is 30min, the heating rate is 10℃ / min, and a pressure of 50MPa is applied to the magnetic mixture during sintering to obtain a conductive and magnetic composite conductor. S3: The conductive and magnetic composite conductor is cut using femtosecond laser processing technology. The parameters of the femtosecond laser are: wavelength 450-500nm, average power 400mW, repetition frequency 150kHz, and scanning speed range of 0.8-1.0 mm / s. A helical flexible composite inductor conductor is obtained. The flexible composite inductor conductor has 8 turns N, a line width W of 60μm, a line spacing d of 10μm, and a thickness T of 10μm.

[0057] Example 4: S1: Take a metallic object and a saturated magnetic powder; the magnetic induction intensity of the saturated magnetic powder is 1.8T; the metallic object is copper powder and silver powder; the magnetic powder is Fe-Co alloy powder; S2: Mix the metal with saturated magnetic powder evenly, with a mass ratio of 1:0.1. Add 1 wt% of the total mass of the metal and saturated magnetic powder to obtain a magnetic mixture. Pour the magnetic mixture into a spiral strip mold and sinter it at low temperature under vacuum atmosphere. The sintering temperature is 150℃, the sintering time is 20 min, the heating rate is 10℃ / min, and a pressure of 10 MPa is applied to the magnetic mixture during sintering to obtain a conductive and magnetic composite conductor. S3: The conductive and magnetic composite conductor is cut using femtosecond laser processing technology. The parameters of the femtosecond laser are: wavelength 450-500nm, average power 400mW, repetition frequency 150kHz, and scanning speed range of 0.8-1.0 mm / s. A helical flexible composite inductor conductor is obtained. The flexible composite inductor conductor has 7 turns N, a line width W of 40μm, a line spacing d of 5μm, and a thickness T of 15μm.

[0058] Example 5: S1: Take a metal object and a saturated soft magnetic tape; the magnetic induction intensity of the magnetic object is 1.7T; the metal object is silver powder; the soft magnetic tape is an Fe-Co-Si-B alloy; S2: Deposit a metal on one side of the saturated flexible magnetic tape using sputtering deposition to form a continuous conductive metal layer on the surface of the saturated flexible magnetic tape, thereby obtaining a layered conductive and magnetic composite conductor; the thickness of the saturated flexible magnetic tape is 30 μm, and the thickness of the conductive metal layer is 10 μm.

[0059] S3: Femtosecond laser processing technology is used to cut the layered conductive and magnetic composite conductor into a spiral shape. The parameters of the femtosecond laser are: wavelength 400-450nm, average power 500mW, repetition frequency 200kHz, and scanning speed in the range of 0.2-0.4mm / s; a spiral flexible composite inductor is obtained. The flexible composite inductor has 3 turns N, a linewidth W of 30μm, a line spacing d of 5μm, and a thickness T of 11μm.

[0060] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A method for preparing a flexible composite inductor with metallic magnetic properties, characterized in that, Includes the following steps: S1: Take a metallic object and a magnetic object; the magnetic induction intensity of the magnetic object is ≥1.6T; S2: Continuously attaching a metal object to a magnetic object to obtain a conductive and magnetically permeable composite conductor; S3: The conductive and magnetic composite conductor is cut using femtosecond laser processing technology to obtain a helical flexible composite inductor conductor.

2. The method for preparing a flexible composite inductor with metallic magnetic properties according to claim 1, characterized in that, Includes the following steps: S1: Take a metal object and a saturated magnetic powder; the magnetic induction intensity of the saturated magnetic powder is ≥1.6T; S2: Mix the metal, saturated magnetic powder and binder evenly, with the mass ratio of metal to saturated magnetic powder being 1:(0.1~3), and the amount of binder added being 0~10wt% of the total mass of the metal and saturated magnetic powder, to obtain a magnetic mixture; pour the magnetic mixture into a spiral strip mold to form it, and sinter it at a low temperature under a protective atmosphere, with a sintering temperature of 100~200℃, to obtain a conductive and magnetic composite conductor; S3: The conductive and magnetic composite conductor is cut using femtosecond laser processing technology to obtain a helical flexible composite inductor conductor.

3. The method for preparing a flexible composite inductor with metallic magnetic properties according to claim 2, characterized in that, In step S1, the metal is metal powder and / or liquid metal; the metal powder includes: At least one of copper, silver, aluminum, gold, iron, and nickel, either in its elemental form or an alloy thereof; The particle size of the metal powder is below 50 nm, and the particle size of the saturated magnetic powder is smaller than that of the metal powder. Liquid metals include at least one of elemental gallium, gallium-indium alloys, and gallium-indium-tin alloys.

4. The method for preparing a flexible composite inductor with metallic magnetic properties according to claim 3, characterized in that, During the low-temperature sintering process in step S2, a pressure of 10 to 100 MPa is applied to the magnetic mixture.

5. A method for preparing a flexible composite inductor with metallic magnetic properties according to any one of claims 2-4, characterized in that, Saturated magnetic powders include at least one of Fe-Co alloy powder, Fe-Ni alloy powder, Fe-Co-B alloy powder, Fe-Si-B-Nb-Cu alloy powder, and Fe-Co-Si-B alloy powder.

6. The method for preparing a flexible composite inductor with metallic magnetic properties according to claim 1, characterized in that, Includes the following steps: S1: Take a metallic object and a saturated soft magnetic tape; the magnetic induction intensity of the magnetic object is ≥1.6T; S2: Deposit metal on the surface of saturated flexible magnetic tape to form a continuous conductive metal layer on the surface of the saturated flexible magnetic tape, so as to obtain a layered conductive and magnetic composite conductor. S3: Femtosecond laser processing technology is used to cut the layered conductive and magnetic composite conductor into a spiral shape to obtain a spiral flexible composite inductor conductor.

7. The method for preparing a flexible composite inductor with metallic magnetic properties according to claim 6, characterized in that, In step S2, a single or multiple metal conductive layers are deposited on the saturated flexible magnetic tape. The thickness of the saturated flexible magnetic tape is 10–30 μm, and the thickness of the metal conductive layers is 1–10 μm.

8. The method for preparing a flexible composite inductor with metallic magnetic properties according to claim 7, characterized in that, In step S1, the alloy strip is selected from Fe-Si-B-Nb-Cu alloy, Fe-Zr-B alloy, Fe-Co-B alloy or Fe-Co-Si-B alloy.

9. A method for preparing a flexible composite inductor with metallic magnetic properties according to any one of claims 6-8, characterized in that, In step S2, the metal is deposited on the surface of the saturated flexible magnetic material by one of the following methods: physical vapor deposition, sputtering deposition, vacuum evaporation, laser-induced deposition, electroplating, or electroless plating.

10. A flexible composite inductor with metallic magnetic properties, characterized in that, A method for preparing a flexible composite inductor with metallic magnetic properties as described in any one of claims 1-9.

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