Inductor and electronic device

Abstract

The utility model provides an inductor and electronic equipment, and relates to the technical field of electronic components. The inductor comprises a skeleton; the one or more layers of laminated strips are wound on the framework, and each laminated strip comprises a conductive material layer, a magnetic material layer and an insulating layer located between the conductive material layer and the magnetic material layer. The inductor structure disclosed by the embodiment of the utility model shows better flexibility; the lamination structure made of the soft magnetic material can realize magnetic flux offset, so that a relatively high inductance value is kept, and relatively low magnetic core loss density is realized.

Description

Technical Field

[0001] The present disclosure relates to the technical field of electronic components, and in particular to an inductor and an electronic device. Background Art

[0002] An inductor is an electronic component used to store electrical energy and hinder current changes. The structure of an inductor generally includes the following types:

[0003] Coil Inductors: Coil inductors are the most common type and consist of wire wound into a coil shape. The wire of the coil is usually insulated to ensure that current flows through the wire without creating a short circuit.

[0004] Iron core inductor: Iron core inductor has a magnetic iron core wrapped around the coil. The iron core can be made of iron oxide, nickel zinc and other materials, which can increase the magnetic induction intensity and the stored magnetic energy.

[0005] Thin film inductors: Thin film inductors are realized by using thin films prepared on a micrometer scale. The thin film can be a thin layer of metal or alloy, forming a coil structure on a substrate.

[0006] Multilayer ceramic inductor: Multilayer ceramic inductor is a surface mount inductor device made of ceramic sheets. It consists of multiple layers of ceramic sheets, with metal electrodes wound alternately on each layer and connected to the circuit board by welding.

[0007] Providing higher inductance value and lower core loss has always been the practical demand of inductor design.

[0008] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0009] The purpose of the present disclosure is to provide an inductor and an electronic device including the inductor, which can at least to some extent overcome the problem of large core loss in the related art.

[0010] Other features and advantages of the present disclosure will become apparent from the following detailed description, or may be learned in part by the practice of the present disclosure.

[0011] According to one aspect of the present disclosure, an inductor is provided, comprising: a skeleton; and one or more layers of laminated tape wound on the skeleton, wherein the laminated tape comprises a conductive material layer, a magnetic material layer, and an insulating layer located between the conductive material layer and the magnetic material layer.

[0012] In one embodiment, the conductive material layer comprises a metal layer.

[0013] In one embodiment, the metal layer includes a copper layer, an aluminum layer, a silver layer, or a stainless steel layer.

[0014] In one embodiment, the magnetic material layer includes a nanocrystalline layer, a nickel-zinc ferrite film, or a manganese-zinc ferrite film.

[0015] In one embodiment, the inductor further includes: an inductor connection terminal electrically connected to the conductive material layer.

[0016] In one embodiment, the inductor connection terminal is not in contact with the magnetic material layer and the insulating layer.

[0017] In one embodiment, the inductor connection terminal is electrically connected to the conductive material layer through PCB patch welding or through a through hole.

[0018] In one embodiment, the magnetic material layer is a nanocrystalline layer, and the insulating layer is an insulating adhesive layer; the laminated strip comprises a nanocrystalline layer, an insulating adhesive layer, a metal layer, an insulating adhesive layer and a nanocrystalline layer arranged in sequence.

[0019] In one embodiment, the thickness of the metal layer is between 0.1 mm and 1 mm, the thickness of the nanocrystalline layer is between 12 μm and 20 μm, and the thickness of the insulating adhesive layer is between 5 μm and 15 μm.

[0020] In one embodiment, the inner radius of the inductor is r1, the outer radius is r2, and the height of the inductor is h; wherein the inner radius is the radius of the skeleton, the outer radius is determined by the thickness of the laminated tape wound on the skeleton and the number of layers of the laminated tape, and the height is determined by the width of the laminated tape.

[0021] In one embodiment, the nanocrystalline layer is an iron-based non-crushed tape or an iron-based crushed tape.

[0022] According to another aspect of the present disclosure, an electronic device is provided, comprising the inductor as described above.

[0023] The inductor and electronic device provided by the embodiments of the present disclosure have an inductor structure that exhibits better flexibility; a laminated structure made of soft magnetic material can achieve magnetic flux cancellation, thereby achieving a lower core loss density while maintaining a relatively high inductance value.

[0024] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification are used to explain the principles of the present disclosure. Obviously, the accompanying drawings described below are only some embodiments of the present disclosure, and for ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without creative work.

[0026] Figure 1A A schematic diagram of the structure of an inductor in an embodiment of the present disclosure is shown;

[0027] Figure 1B An inductor equivalent circuit diagram in an embodiment of the present disclosure is shown;

[0028] Figure 2 A schematic structural diagram of a cross-section of an inductor in another embodiment of the present disclosure is shown;

[0029] FIG. 3A to FIG. 3D showing different shapes of cross-sections of the skeleton in the disclosed embodiments; and

[0030] Figure 4 A schematic diagram showing a comparison of inductance and core loss between a novel inductor and a traditional Litz wire inductor in one embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0031] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that the disclosure will be more comprehensive and complete and to fully convey the concepts of the example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0032] In addition, the accompanying drawings are only schematic illustrations of the present disclosure and are not necessarily drawn to scale. The same reference numerals in the drawings represent the same or similar parts, and thus their repeated description will be omitted.

[0033] The technical solution provided by the present disclosure relates to an inductor. For ease of understanding, several terms involved in the present disclosure are first explained below.

[0034] Nanocrystalline ribbon is a special metal ribbon with nanocrystalline structure characteristics. It consists of a series of thin metal ribbons, each of which is usually tens to hundreds of nanometers thick and a few millimeters to centimeters wide. Nanocrystalline ribbons are usually made of high-purity metals or alloys, such as iron, nickel, cobalt, etc. Its preparation process includes technologies such as rapid solidification or magnetron sputtering, which can quickly cool the metal solution in a short time to form a thin film with a nanocrystalline structure. Nanocrystalline ribbons have many special physical and chemical properties, which make them widely used in many fields. It has the characteristics of high saturation magnetic induction, low hysteresis loss, excellent magnetic conductivity and high resistivity, and is widely used in power electronics, transformers, sensors, magnetic storage and other fields. Its special nanocrystalline structure gives it excellent magnetic and electrical properties, and can achieve high efficiency and high power density applications in the electromagnetic field. In general, nanocrystalline ribbon is a metal ribbon with a special structure, which has excellent magnetic and electrical properties and is widely used in various fields.

[0035] Nanocrystalline soft magnetic materials are a type of soft magnetic materials with nanocrystalline structural characteristics. They are composed of a metal matrix with nanocrystalline grain size and suitable alloying elements. The nanocrystalline grain size is usually between a few nanometers and tens of nanometers. Compared with traditional micron-sized grain materials, nanocrystalline materials have smaller magnetic domain sizes and higher saturation permeability, and have better soft magnetic properties. Nanocrystalline soft magnetic materials have the following characteristics:

[0036] 1. High saturation flux density: It has a higher magnetic saturation induction intensity and can store a higher magnetic flux.

[0037] 2. Low hysteresis loss: It has a lower hysteresis loop area, showing lower hysteresis loss and remanence.

[0038] 3. High magnetic permeability: With higher magnetic permeability, it can provide lower inductive resistance.

[0039] 4. Wide frequency response: It exhibits a wide frequency response range and is suitable for high-frequency applications. Nanocrystalline soft magnetic materials are widely used in power electronics, transformers, inductors, sensors, magnetic storage, high-frequency inductors, electric vehicles, magnetic transmissions, and magnetic amplifiers. By optimizing the alloy composition and preparation process, the magnetic properties of nanocrystalline soft magnetic materials can be further regulated to meet the needs of different applications.

[0040] Nanocrystalline soft magnetic materials can be used to manufacture nanocrystalline ribbons.

[0041] Two-dimensional Maxwell simulation refers to a two-dimensional electromagnetic field simulation method based on Maxwell's equations. Maxwell's equations are the basic physical equations that describe the behavior of electromagnetic fields, including Maxwell's laws and the continuity equation of electromagnetic fields. Two-dimensional Maxwell simulation usually refers to solving Maxwell's equations on a two-dimensional plane using numerical methods to simulate the spatial distribution and propagation characteristics of electromagnetic fields. This simulation method is widely used in electromagnetic field simulation and design, and can be used to analyze electromagnetic wave propagation, field intensity distribution, reflection and transmission. In two-dimensional Maxwell simulation, a numerical method such as finite difference method (FDM), finite element method (FEM) or finite difference time domain (FDTD) is usually used to discretize Maxwell's equations, and the distribution of electromagnetic fields is obtained by iterative solution. Two-dimensional Maxwell simulation is widely used in electromagnetic wave propagation and radiation, waveguide transmission, microwave device design and other fields. It can help engineers and scientists understand and optimize the behavior of electromagnetic fields and provide important guidance when designing electromagnetic devices and systems.

[0042] The embodiments of the present disclosure propose a highly integrated inductor design that combines a conductive material layer and a magnetic material layer. By laminating a conductive material layer, an insulating layer, and a magnetic material layer together to form a laminated strip of an inductor, the laminated strip is wound together to form an inductor, wherein the conductive material layer serves as the winding of the inductor, and the magnetic material layer serves as the soft magnetic material of the inductor, forming a unique structure of the inductor. This is different from the separate winding and core structure of the traditional inductor, and the inductor structure of the embodiment of the present disclosure exhibits better flexibility. Different inductance values ​​can be achieved by winding into a specific geometric shape without changing the raw materials. In addition, the laminated structure using soft magnetic materials can achieve flux cancellation, thereby achieving a lower core loss density while maintaining a relatively high inductance value. Compared with traditional power inductors, the inductor structure of the embodiment of the present disclosure has a higher power density.

[0043] In one embodiment, the conductive material layer includes a metal layer, and the material of the metal layer is, for example, copper, aluminum, silver or stainless steel. In one embodiment, the magnetic material layer can be a nanocrystalline layer, a nickel-zinc ferrite film or a manganese-zinc ferrite film, etc. In one embodiment, the nanocrystalline ribbon can be an original iron-based non-broken ribbon, or an iron-based broken ribbon can be formed into an air-gapped broken screen structure to enhance flexibility.

[0044] In one embodiment, the insulating layer is an insulating adhesive layer and also acts as an adhesive layer, such as a pressure sensitive adhesive (PSA), or other adhesive and insulating materials. The adhesive layers in the inductor structure have multiple purposes. First, they provide mechanical integrity to the overall design; second, they ensure isolation between layers, help electrical insulation and prevent conduction between conductive material layers (such as copper layers) and magnetic material layers (such as nanocrystalline layers).

[0045] In one embodiment, copper foil and nanocrystalline ribbon are wound together to form an inductor, forming a unique structure that combines windings (copper foil) and soft magnetic materials (nanocrystalline materials) together. Through the integrated design and utilization of copper foil and nanocrystalline ribbon, it has obvious advantages in flexibility, inductance customization and reduced core loss.

[0046] Hereinafter, the structure of the inductor in this exemplary embodiment will be described in more detail with reference to the accompanying drawings and embodiments.

[0047] Figure 1A FIG. 2 shows a schematic diagram of the structure of an inductor according to an embodiment of the present disclosure. Figure 1A As shown, the inductor is formed by winding one or more layers of laminated tape 11. Figure 1A The left side is a structural view of the inductor, and the right side is a cross-sectional view of the laminated strip 11 along the AB direction. Each laminated strip 111 in the laminated strip 11 includes a conductive material layer 1111, two magnetic material layers 1112, and multiple insulating layers 1113. In one embodiment, each laminated strip includes a nanocrystalline layer, an insulating adhesive layer, a metal layer, an insulating adhesive layer, and a nanocrystalline layer arranged in sequence.

[0048] In one embodiment, the integrated inductor is made of a novel laminate structure of copper foil and nanocrystalline strip. Each unit layer structure consists of a copper layer 1111, multiple adhesive layers 1113 and multiple nanocrystalline layers 1112. The thickness of the copper layer is t c , the thickness of the nanocrystalline layer is t f , the thickness of the adhesive layer is t a The copper layer is used as the winding of the inductor and the nanocrystalline layer is used as the soft magnetic core. The nanocrystalline layer has a high magnetic permeability, which effectively reduces the magnetic resistance around the copper layer and significantly improves the inductance. In addition, the symmetrical structure of the unit layers enables magnetic flux, thereby preventing excessive flux density in the nanocrystalline layer between the two copper layers. The core losses can be kept at a low level. The bonding layers in this structure serve multiple purposes. They provide mechanical integrity to the overall design, ensure isolation between the layers, help with electrical insulation and prevent conduction between the copper layer and the nanocrystalline layer.

[0049] In one embodiment, by winding the unit layer structure into a complete inductor, such as Figure 1A As shown. The inner radius of the inductor is r1, the outer radius is r2, and the height of the inductor is h. The size of the inductor can be defined by these three parameters: the inner radius is determined by the skeleton, the outer radius is determined by the thickness of a layer of laminated tape wound on the skeleton and the number of layers of the laminated tape, and the height is determined by the width of the laminated tape. In one embodiment, the thickness of the metal layer (such as a copper layer) can be between 0.1 mm and 1 mm. The thickness of the nanocrystalline layer is typically in the range of 12μm to 20μm, while the thickness of the insulating adhesive layer is in the range of 5μm to 15μm. These adjustable parameters allow the inductor design to be customized and optimized to meet the specific needs of various applications.

[0050] In one embodiment, the inductor further includes inductor connection terminals S1 and S2, and the inductor connection terminals S1 and S2 are electrically connected to the conductive material layer 1111. In one embodiment, the inductor connection terminals S1 and S2 are not in contact with the magnetic material layer 1112 and the insulating layer 1113. In one embodiment, the inductor connection terminals S1 and S2 are electrically connected to the conductive material layer 1111 through PCB (Printed Circuit Board) patch welding or through holes.

[0051] Figure 1B FIG. 2 shows an inductor equivalent circuit diagram in an embodiment of the present disclosure. Figure 1B As shown, the circuit includes an inductor connecting terminals S1 and S2, an inductor L1 and a capacitor C1 located between the terminals S1 and S2.

[0052] Figure 2 FIG. 2 is a schematic diagram showing a cross-sectional structure of an inductor in another embodiment of the present disclosure. Figure 2 As shown, the inductor (not shown) is wound by winding multiple layers of laminated strips 21. Each layer of laminated strips 211 in the laminated strips 21 includes two conductive material layers 2111, two magnetic material layers 2112 and multiple insulating layers 2113.

[0053] Those skilled in the art can implement other variations and combinations based on the teachings of the embodiments of the present disclosure.

[0054] FIG. 3A to FIG. 3D 1 and 2 show different shapes of cross-sections of the skeleton in the embodiments of the present disclosure. Figure 3A Shown is Figure 1A The circular shape in the embodiment, Figure 3B Shown is a square. Figure 3C The oval is shown. Figure 3D The skilled person in the art will appreciate that by making full use of the flexibility of the strip, the shape of the skeleton can be determined as required, thereby forming different shapes around it.

[0055] The following briefly introduces the implementation of an integrated inductor that forms a stacked structure.

[0056] (1) A conductive material layer (e.g., copper foil or aluminum foil) and a magnetic material layer (e.g., nanocrystalline strip) are formed into a laminated structure by means of an adhesive, wherein each unit of the laminated structure includes a copper layer, multiple insulating adhesive layers, and a nanocrystalline layer, and the laminated strip is obtained by combining them.

[0057] (2) The combined laminated strip is coaxially wound on a frame to form an inductor. The conductive material layer (e.g., copper foil or aluminum foil) serves as a winding, and the magnetic material layer (e.g., nanocrystalline strip) serves as a soft magnetic material, and the two are integrated into one. The inductor connection terminal does not contain a nanocrystalline layer and an adhesive layer to ensure minimum contact resistance. The inductor connection terminal can be a PCB patch soldering or a through-hole connection.

[0058] Furthermore, the required inductance value can be obtained with the help of finite element simulation.

[0059] In one embodiment, finite element simulation is used to evaluate the performance and determine the inductance value. Thanks to the axisymmetric structure, a simplified two-dimensional Maxwell simulation can be performed on the proposed inductor structure. The simulation is performed and compared with a conventional inductor with a core Litz wire. The parameters of the inductor example using the proposed laminated structure are shown in Table 1 below:

[0060] Table 1

[0061] parameter value <![CDATA[Thickness t of the copper layer c > 0.1mm <![CDATA[Thickness t of the nanocrystalline layer f > 0.02mm <![CDATA[Thickness t of the adhesive layer a > 0.01mm The number of copper layers in each layer structure 1 The number of nanocrystalline layers in each layer structure 2 Number of adhesive layers per structure 4 The number of layers of the structure included in the inductor 50 <![CDATA[Inner radius r1]]> 10mm <![CDATA[Outer radius r2]]> 19mm Height 20mm

[0062] Figure 4 The simulation results shown compare the inductance and core loss between the new inductor and the conventional Litz wire inductor in the embodiment of the present disclosure. The size of the new inductor of the present disclosure matches the core size of the conventional inductor. The conventional inductor is wound with 3 turns of Litz wire, so its physical size is larger than the novel structure. The simulation was performed with a sinusoidal excitation of 3A and a frequency of 50kHz. The results show that the new inductor using the proposed integrated structure exhibits a higher inductance value of 89.28μH, while the conventional inductor only reaches 76.68μH. In addition, due to the flux cancellation effect, the proposed integrated inductor exhibits extremely low core loss. The core loss is significantly reduced from 12.72W for the conventional inductor to 0.44W for the new inductor. It is worth noting that the winding loss caused by the use of Litz wire winding in the conventional inductor is negligible. On the other hand, the new inductor uses copper foil, and the skin effect of copper will cause an additional 5.10W winding loss. As a result, the new inductor has a significantly reduced core loss of 60% and a 16.3% increase in inductance compared to conventional inductors.

[0063] A method for producing an iron-based amorphous nanocrystalline strip is provided below, comprising the following steps:

[0064] 1) iron, copper, cobalt, nickel, zinc, titanium, manganese and carbon are configured according to weight percentage, wherein: iron is 50%-90%, copper is 1.2%-5.0%, cobalt is 2.8%-15%, nickel is 2.8%-12%, zinc is 1.1%-8.8%, titanium is 1.5%-5.0%, manganese is 0.5%-3.5%, and carbon is 0.1%-0.7%;

[0065] 2) Place the proportioned raw materials in a smelting furnace and melt them at a temperature above 1500°C;

[0066] 3) After the molten product is output through a pipeline, it is evenly sprayed on a copper foil substrate carrier through a ceramic nozzle and rapidly cooled to form a continuous amorphous alloy strip;

[0067] 4) placing the amorphous alloy continuous strip in a vacuum annealing tunnel furnace and subjecting it to a transverse, longitudinal or transverse and longitudinal staggered magnetic field at 300° C.-750° C. for annealing and crystallization treatment;

[0068] 5) After the annealed and crystallized strip is passed through an alloy rolling machine, it is die-cut to obtain a nanocrystalline strip of required width.

[0069] The inductor disclosed herein can be applied to various electronic devices. For example, it can be used as a power inductor for power conversion applications, and the applications of the inductor include power supplies, electronics, automotive systems, telecommunications, industrial and medical equipment, etc.

[0070] The integrated inductor design has significant advantages in terms of high power density and low core loss. Simulation results show that the core loss is significantly reduced by 60% and the inductance is increased by 16.3% compared to the traditional design. In addition, the structure composed of copper foil and nanocrystalline ribbons provides a high degree of flexibility for inductor manufacturing. Inductors with different inductance values ​​can be easily produced by simply winding more unit layers of the proposed structure. This flexibility allows customization and adaptability to meet specific application requirements.

[0071] In addition, although the steps of the method in the present disclosure are described in a specific order in the drawings, this does not require or imply that the steps must be performed in this specific order, or that all the steps shown must be performed to achieve the desired results. Additionally or alternatively, some steps may be omitted, multiple steps may be combined into one step, and / or one step may be decomposed into multiple steps, etc.

[0072] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any modification, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the appended claims.

Claims

1. An inductor, characterized in that: include: skeleton; One or more layers of laminated tape are wound on the skeleton, and the laminated tape includes a conductive material layer, a magnetic material layer, and an insulating layer located between the conductive material layer and the magnetic material layer.

2. The inductor according to claim 1, characterized in that The conductive material layer includes a metal layer.

3. The inductor according to claim 2, characterized in that The metal layer includes a copper layer, an aluminum layer, a silver layer, or a stainless steel layer.

4. The inductor according to any one of claims 1 to 3, characterized in that: The magnetic material layer includes a nanocrystalline layer, a nickel-zinc ferrite film, or a manganese-zinc ferrite film.

5. The inductor according to claim 4, characterized in that Also includes: The inductor connection terminal is electrically connected to the conductive material layer.

6. The inductor according to claim 5, characterized in that The inductor connection terminal is not in contact with the magnetic material layer and the insulating layer; and / or The inductor connection terminal is electrically connected to the conductive material layer through printed circuit board PCB patch welding or through-hole.

7. The inductor according to claim 2, characterized in that The magnetic material layer is a nanocrystalline layer, and the insulating layer is an insulating adhesive layer; the laminated strip comprises a nanocrystalline layer, an insulating adhesive layer, a metal layer, an insulating adhesive layer and a nanocrystalline layer which are arranged in sequence.

8. The inductor according to claim 7, characterized in that The thickness of the metal layer is between 0.1 mm and 1 mm, the thickness of the nanocrystalline layer is between 12 μm and 20 μm, and the thickness of the insulating adhesive layer is between 5 μm and 15 μm.

9. The inductor according to claim 1, wherein: The inner radius of the inductor is r1, the outer radius is r2, and the height of the inductor is h; The inner radius is the radius of the skeleton, the outer radius is determined by the thickness of the laminated strip wound on the skeleton and the number of layers of the laminated strip, and the height is determined by the width of the laminated strip.

10. The inductor according to claim 4, characterized in that The nanocrystalline layer is an iron-based non-broken strip or an iron-based broken strip.

11. An electronic device, characterized in that: Comprising the inductor according to any one of claims 1 to 10.

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