WO2024060450A1

WO2024060450A1 - Inductor and inductor manufacturing method

Info

Publication number: WO2024060450A1
Application number: PCT/CN2022/142422
Authority: WO
Inventors: 刘海波; 周小兵; 刘攀
Original assignee: 昆山玛冀电子有限公司
Priority date: 2022-09-22
Filing date: 2022-12-27
Publication date: 2024-03-28
Also published as: CN115440499A

Abstract

The present application relates to an inductor manufacturing method. The method comprises: acquiring an inductance coil wound into a predetermined shape; coating a soft magnetic powder solution having a first magnetic permeability on the inductance coil to obtain an inductance coil having a first structure; drying the inductance coil having the first structure to obtain an inductance coil having a second structure of which the surface is coated with first thickness of powder; putting the inductance coil having the second structure into an inductance mold, and filling the inductance mold with soft magnetic powder having a second magnetic permeability, the second magnetic permeability being greater than the first magnetic permeability; and pressing the inductance mold filled with the soft magnetic powder having the second magnetic permeability to obtain a pressed inductor. By using the present method, highly-saturated soft magnetic powder and lowly-saturated soft magnetic powder can be combined, such that a saturated current of the inductor can be increased.

Description

An inductor and a method of making an inductor

Technical Field

The present application relates to the technical field of electronic components, and in particular to an inductor and a method of making an inductor.

Background technique

Inductors, as energy storage components, are widely used in various electronic devices. Currently, due to changes in consumer demand and the development of product manufacturing processes, many products are moving towards smaller sizes. As the size of the inductor becomes smaller and smaller, the saturation current will become larger and larger.

In the related art, in order to increase the saturation current of the inductor, powder with a larger magnetic flux density is generally used to make the inductor coil. However, as the magnetic flux density increases, the magnetic permeability will decrease, thereby affecting the inductance value. If a powder with a higher magnetic flux density is used, the magnetic permeability will decrease. If a powder with a smaller magnetic flux density is used, the magnetic permeability will increase, and a balance between magnetic permeability and saturation current cannot be achieved.

Contents of the invention

Based on this, it is necessary to provide an inductor to solve the above technical problems, which can use soft magnetic powder with high saturation current and soft magnetic powder with low saturation current to match each other to increase the saturation current.

In a first aspect, this application provides an inductor manufacturing method. The methods include:

Obtain an inductor coil wound into a predetermined shape;

Apply the soft magnetic powder solution of the first magnetic permeability on the inductor coil to obtain the inductor coil of the first structure; dry the inductor coil of the first structure to obtain the second inductor coil whose surface is covered with the first thickness of powder. structural inductor coil;

Put the inductor coil of the second structure into an inductor mold, fill the inductor mold with soft magnetic powder with a second magnetic permeability, and the second magnetic permeability is greater than the first magnetic permeability;

The inductor mold filled with the soft magnetic powder of the second magnetic permeability is pressed to obtain a pressed inductor.

In one embodiment, applying the soft magnetic powder solution of the first magnetic permeability to the inductor coil includes immersing the inductor coil in the soft magnetic powder solution of the first magnetic permeability.

In one embodiment, applying the soft magnetic powder solution of the first magnetic permeability to the inductor coil includes spraying the soft magnetic powder solution of the first magnetic permeability onto the inductor coil.

In one embodiment, the first thickness ranges from 0.05 mm to 0.1 mm.

In one embodiment, the predetermined shape is obtained by using a round wire or a flat wire for horizontal or vertical winding.

In one embodiment, drying the inductor coil of the first structure includes placing the inductor coil of the first structure into an oven to bake for drying.

In one embodiment, the drying of the inductor coil of the first structure includes drying the inductor coil of the first structure by baking it with a hot air gun.

In one embodiment, the soft magnetic powder includes at least one of iron silicon chromium powder, iron silicon aluminum powder, carbonyl powder, amorphous powder, nanocrystalline powder, manganese zinc powder, and nickel zinc powder.

In one embodiment, an inductor is produced based on any one of the above methods.

In one embodiment, the size of the inductor is 1680 or more.

The above-mentioned inductor and the method for making the inductor include at least the following beneficial effects:

In the embodiment provided by the present disclosure, soft magnetic powder with a first magnetic permeability and a soft magnetic powder with a second magnetic permeability can be selected, and the second magnetic permeability is greater than the first magnetic permeability. It can solve the problem that the magnetic flux density distribution of the inductor coil is uneven. The closer to the coil, the higher the magnetic flux density, and at the same time, the inductor saturation current needs to be increased. Apply the soft magnetic powder solution of the first magnetic permeability to the inductor coil to obtain the inductor coil of the first structure, and then dry the inductor coil of the first structure to obtain a surface coverage of the first thickness Powder to the second structure of the inductor coil. The inductor mold filled with the soft magnetic powder of the second magnetic permeability is pressed to obtain a pressed inductor.

It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only, and do not limit the present disclosure.

Description of drawings

In order to more clearly explain the embodiments of the present disclosure or the technical solutions in the traditional technology, the drawings needed to be used in the description of the embodiments or the traditional technology will be briefly introduced below. Obviously, the drawings in the following description are only for the purpose of explaining the embodiments or the technical solutions of the traditional technology. For some disclosed embodiments, those of ordinary skill in the art can also obtain other drawings based on these drawings without exerting creative efforts.

Figure 1 is a schematic diagram of an inductor manufacturing method in an embodiment;

Figure 2 is a schematic diagram of the magnetic flux density distribution of the inductor in one embodiment;

Figure 3 is a schematic diagram of the relationship between magnetic permeability and magnetic flux in one embodiment;

Figure 4 is a table showing changes in inductance values under different magnetic permeabilities in one embodiment.

Detailed ways

To facilitate understanding of the present disclosure, the present disclosure will be described more fully below with reference to the relevant drawings. Embodiments of the present disclosure are illustrated in the accompanying drawings. However, the present disclosure may be embodied in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and comprehensive understanding of the present disclosure.

In this disclosure, unless otherwise explicitly stated and limited, the terms "installation", "connection", "connection", "fixing" and other terms should be understood in a broad sense. For example, it can be a fixed connection or a detachable connection. , or integrated; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be an internal connection between two elements or an interactive relationship between two elements, unless otherwise specified restrictions. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

The terms “first” and “second” are used for descriptive purposes only and shall not be understood as indicating or implying relative importance or implicitly indicating the quantity of indicated technical features. Therefore, features defined as "first" and "second" may explicitly or implicitly include at least one of these features. In the description of the present disclosure, "plurality" means at least two, such as two, three, etc., unless otherwise expressly and specifically limited.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terminology used herein in the description of the disclosure is for the purpose of describing specific embodiments only and is not intended to limit the disclosure. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

In some embodiments of the present disclosure, a method for making an inductor is provided. Inductors are widely used in various electronic devices as energy storage elements. Inductors generally contain a magnetic core. Due to the characteristics of the magnetic core material itself, the magnetic flux passing through it cannot be increased infinitely. When the magnetic flux passing through a certain volume of magnetic core material reaches a certain amount, the magnetic flux may no longer increase regardless of whether the current passing through or the number of turns of the inductor coil is increased. When the current has saturated the magnetic core, increasing the current may not increase the magnetic flux, or increase it very little. If the current increases but the magnetic flux does not increase, then the inductor has no effect of hindering the current, that is, the inductor loses its function. Saturation current generally refers to a bias current at which the inductance value decays by 20% to 40% relative to the initial value. When the current is relatively small, the magnetic flux generated by the unit current is proportional to the current. As the current slowly increases, the increment of the magnetic flux generated by the increase in the unit current decreases, that is, as the current increases, the magnetic permeability slowly decreases, and therefore, the inductance of the inductor also decreases. In actual application, the inductor will not be fully saturated until it is fully saturated. The inductor is fully saturated because the magnetic core is saturated. As long as the current reaches a certain value, the magnetic core may be saturated. Therefore, in circuit design, the saturation current can be set so that the maximum current value of the inductor does not exceed the saturation current.

In order to meet the requirements of various products, the size of the inductor needs to be smaller and smaller, and the saturation current needs to be larger and larger. Therefore, the present disclosure provides an inductor manufacturing method.

In a specific embodiment, as shown in Figure 1, the method may include the following steps:

S202: Obtain an inductor coil wound into a predetermined shape.

According to different methods, inductor coils can be divided into different categories. According to the material and properties of the magnetic conductor, it can be divided into copper core coil, iron core coil, ferrite coil and air core coil. According to the form of the inductor and whether it can change its shape, it can be classified into variable inductor and fixed inductor. According to different working functions and properties, they can be divided into deflection coils, oscillation coils, choke coils, etc. The inductor coil wound into a predetermined shape can be selected according to actual needs. The inductor coil of the preset shape can include a toroidal inductor, an I-shaped inductor, etc. For example, in some embodiments of the present disclosure, if a larger inductance is required, an inductor coil with a larger number of turns can be selected.

S204: Apply the soft magnetic powder solution with the first magnetic permeability on the inductor coil to obtain the inductor coil with the first structure.

Soft magnetic powder can refer to some magnetic materials that are easy to magnetize and demagnetize. The "softness" of soft magnetic powder means that these materials are easily magnetized and appear "soft" magnetically. The magnetic permeability of different soft magnetic powders can be different. In some embodiments of the present disclosure, a soft magnetic powder solution with a first magnetic permeability can be applied on the inductor coil to obtain an inductor coil with a first structure. The inductor coil with the first structure can be obtained by soaking, spraying, coating, wiping, etc. Compared with the traditional pressing method, the above method can be used to achieve uniform coverage of the soft magnetic powder solution with the first magnetic permeability on the surface of the inductor coil. It should be noted that the application of the soft magnetic powder solution in the inductor coil described in this embodiment means that the soft magnetic powder solution can be covered in all or part of the inductor coil by soaking, spraying, coating, wiping, etc. does not limit a specific processing method.

S206: Dry the inductor coil of the first structure to obtain an inductor coil of the second structure whose surface is covered with powder of the first thickness.

Since the soft magnetic powder solution of the first magnetic permeability completely covers the surface of the inductor coil, the inductor coil of the first structure can be dried, and the soft magnetic powder solution of the first magnetic permeability is dried to obtain a surface coverage of the first thickness. Powder to the second structure of the inductor coil.

S208: Place the inductor coil of the second structure into an inductor mold, and fill the inductor mold with soft magnetic powder of a second magnetic permeability, where the second magnetic permeability is greater than the first magnetic permeability.

The inductor coil of the second structure can be placed into the inductor mold. The size of the inductor mold can be larger than the size of the inductor coil of the second structure. The soft magnetic powder of the second magnetic permeability can be filled into the remaining gap in the inductor mold. Because this part of the position has little impact on the saturation current, there is no need to limit the size of the remaining gap in the inductor mold.

In order to increase the saturation current of the inductor, a powder with a larger magnetic flux density can be used. The magnetic permeability of this material is generally very low, and the low magnetic permeability will affect the inductance value. If the saturation current of the soft magnetic powder is high, the magnetic permeability may be low. If the soft magnetic powder selected has a high magnetic permeability, the saturation current may be poor. In some embodiments of the present disclosure, a soft magnetic powder with a first magnetic permeability and a soft magnetic powder with a second magnetic permeability can be selected, and the second magnetic permeability is greater than the first magnetic permeability. As shown in Figure 2, it is a schematic diagram of the distribution of the magnetic flux density of the inductor in one embodiment. It can solve the problem that the magnetic flux density distribution of the inductor coil is uneven, the closer to the coil, the higher the magnetic flux density, and at the same time, the saturation current of the inductor needs to be increased. The magnetic permeability and magnetic flux density of the soft magnetic powder are nonlinear. The higher the magnetic flux density, the lower the magnetic permeability. As shown in Figure 3, it is a schematic diagram of the relationship curve between magnetic permeability and magnetic flux in one embodiment, where B1 can represent the soft magnetic powder of the first magnetic permeability, and B2 can represent the soft magnetic powder of the second magnetic permeability. In some embodiments of the present disclosure, soft magnetic powder (B1) with low magnetic permeability and high saturation current can be used in the space near the coil, and soft magnetic powder (B2) with high magnetic permeability and low saturation current can be used in the space far away from the coil, which can effectively increase the saturation current of the inductor.

S210: Press the inductor mold filled with the soft magnetic powder with the second magnetic permeability to obtain a pressed inductor.

Apply the soft magnetic powder solution of the first magnetic permeability to the inductor coil to obtain the inductor coil of the first structure, and then dry the inductor coil of the first structure to obtain a surface coverage of the first thickness Powder to the second structure of the inductor coil. Since the inductor coil of the second structure has been formed, a pressing method can be selected to press the soft magnetic powder of the second magnetic permeability around the inductor coil of the first structure to obtain a pressed inductor.

In the manufacturing method of the above inductor, soft magnetic powder with first magnetic permeability can be used in the space close to the coil, and soft magnetic powder with second magnetic permeability can be used in the space far away from the coil. The second magnetic permeability is greater than the first magnetic permeability. Conductivity. It can solve the problem that the magnetic flux density distribution of the inductor coil is uneven. The closer to the coil, the higher the magnetic flux density, which makes it difficult to further increase the inductor saturation current.

As shown in Figure 4, it is a table of changes in inductance values under different magnetic permeabilities in one embodiment. When the inductor coil is entirely made of soft magnetic powder with a second magnetic permeability, the initial inductance reaches saturation at 0.471 microhenries (μH). The soft magnetic powder with a second magnetic permeability has high magnetic permeability and poor saturation current. When the inductor produced using the soft magnetic powder with the second magnetic permeability reaches a saturation current of 8.5 amperes (A), the inductance value is 0.298 microhenry, and the change rate is 36.73%. When the inductor coil is entirely made of soft magnetic powder with the first magnetic permeability, the initial inductance value is 0.363 microhenries (μH) and reaches saturation. The soft magnetic powder with the first magnetic permeability has low magnetic permeability and high saturation current. When the inductor produced using the soft magnetic powder with the first magnetic permeability reaches a saturation current of 8.5 amperes (A), the inductance value is 0.29 microhenry, and the change rate is 20.11%. In some embodiments of the present disclosure, soft magnetic powder with a first magnetic permeability and soft magnetic powder with a second magnetic permeability may be selected, and the second magnetic permeability is greater than the first magnetic permeability. The soft magnetic powder (B1) of the first magnetic permeability can be used in the space close to the coil, and the soft magnetic powder (B2) of the second magnetic permeability can be used in the space far away from the coil. The initial inductance value is 0.443 microhenries and reaches saturation. When the saturation current is 8.5 amps (A), the inductance value is 0.332 microhenries, and the change rate is 25.06%.

In some embodiments of the present disclosure, the inductor coil can be immersed in a soft magnetic powder solution with a first magnetic permeability, which can ensure that the soft magnetic powder solution with a first magnetic permeability fully covers the surface of the inductor coil. The magnetic flux density distribution of the inductor coil is uneven. The closer to the coil, the higher the magnetic flux density and the lower the magnetic permeability. The soft magnetic powder solution with the first magnetic permeability evenly covers the surface of the inductor coil, which can ensure that the soft magnetic powder with the first magnetic permeability is evenly wrapped in the part close to the inductor during subsequent operations, reducing the magnetic permeability and increasing the saturation current of the inductor.

In one embodiment, applying the soft magnetic powder solution of the first magnetic permeability on the inductor coil includes spraying the soft magnetic powder solution of the first magnetic permeability on the inductor coil.

In some embodiments of the present disclosure, the soft magnetic powder solution with the first magnetic permeability can be sprayed on the inductor coil multiple times, which can ensure that the soft magnetic powder solution with the first magnetic permeability evenly covers the surface of the inductor coil.

In one embodiment, the first thickness is 0.05 mm to 0.1 mm.

In some embodiments of the present disclosure, the inductor coil of the first structure is dried to obtain an inductor coil of the second structure whose surface is covered with powder of the first thickness. The thickness of the powder may have a certain impact on the increase of the saturation current of the inductor. . The magnetic flux density distribution of the inductor coil is uneven. The closer to the coil, the higher the magnetic flux density and the lower the magnetic permeability. The soft magnetic powder solution with the first magnetic permeability can be used in the part closest to the inductor coil, which can increase the saturation current of the inductor. The first thickness provided in this embodiment ranges from 0.05 mm to 0.1 mm, which can better improve the magnetic flux density of the coil, reduce the magnetic permeability, and increase the saturation current.

In one embodiment, the predetermined shape is obtained by horizontal or vertical winding using round wire or flat wire.

In some embodiments of the present disclosure, the inductor coil is made of wires wound in a certain shape, and the shape of the wires can be round wires or flat wires. You can choose horizontal winding or vertical winding according to the actual use needs and production process. The vertical winding method has better heat dissipation effect and may have better ability to withstand instantaneous high current. The horizontal winding method can reduce the floor space. The inductor coil can be made by horizontal or vertical winding of round wire, or it can be made of horizontal or vertical winding of flat wire.

In one embodiment, the drying process of the inductor coil of the first structure includes placing the inductor coil of the first structure in an oven for baking and drying.

In some embodiments of the present disclosure, since the soft magnetic powder solution of the first magnetic permeability is applied to the inductor to obtain the inductor of the first structure, the inductor of the first structure can be dried. The inductor of the first structure can be placed in an oven for baking, and the soft magnetic powder solution of the first magnetic permeability is dried to obtain the inductor of the second structure whose surface is covered with the powder of the first thickness.

In one embodiment, drying the inductor coil of the first structure includes drying the inductor coil of the first structure using a heat gun.

In some embodiments of the present disclosure, a hot air gun can be used to bake the inductor coil of the first structure, and an inductor coil of the second structure whose surface is covered with powder of the first thickness can be obtained.

Different soft magnetic powders have high and low magnetic permeabilities, which can be selected according to actual design.

In some embodiments of the present disclosure, a soft magnetic powder with a first magnetic permeability may be used in a space close to the coil, and a soft magnetic powder with a second magnetic permeability may be used in a space far away from the coil, and the second magnetic permeability is greater than the first magnetic permeability. 1. Magnetic permeability. The soft magnetic powder with the first magnetic permeability and the soft magnetic powder with the second magnetic permeability may be the same soft magnetic powder, or they may be two different soft magnetic powders. For example, the magnetic permeability of nanocrystals can be adjusted at will within the range of 1,000-30,000, and soft magnetic powder with adapted magnetic permeability can be selected according to actual needs.

In one embodiment, an inductor is fabricated based on any one of the above methods.

In one embodiment, the size of the inductor is 1680 or more.

The size of the inductor can include 1005, 1680, 2012, 3216, etc. The package size of the inductor can represent the length, width, and height of the inductor. For example, in some embodiments of the present disclosure, the size of the inductor may be selected to be 1680 or more.

It should be understood that although the steps in the flowcharts involved in the above-mentioned embodiments are shown in sequence as indicated by the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated in this article, there is no strict order restriction on the execution of these steps, and these steps can be executed in other orders. Moreover, at least some of the steps in the flowcharts involved in the above embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily executed at the same time, but may be completed at different times. The execution order of these steps or stages is not necessarily sequential, but may be performed in turn or alternately with other steps or at least part of the steps or stages in other steps.

The technical features of the above embodiments can be combined in any way. To simplify the description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, all possible combinations should be used. It is considered to be within the scope of this manual.

The above-described embodiments only express several implementation modes of the present disclosure, and their descriptions are relatively specific and detailed, but should not be understood as limiting the patent scope of the present disclosure. It should be noted that, for those of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present disclosure, and these all fall within the protection scope of the present disclosure. Therefore, the scope of protection of the present disclosure should be determined by the appended claims.

Claims

An inductor manufacturing method, characterized in that the method includes:

Obtain an inductor coil wound into a predetermined shape;

Apply the soft magnetic powder solution of the first magnetic permeability on the inductor coil to obtain the inductor coil of the first structure;

Perform a drying process on the inductor coil of the first structure to obtain an inductor coil of the second structure whose surface is covered with powder of the first thickness;

Put the inductor coil of the second structure into an inductor mold, fill the inductor mold with soft magnetic powder with a second magnetic permeability, and the second magnetic permeability is greater than the first magnetic permeability;

The inductor mold filled with the soft magnetic powder of the second magnetic permeability is pressed to obtain a pressed inductor.
The method of claim 1, wherein applying the soft magnetic powder solution of the first magnetic permeability to the inductor coil includes soaking the inductor coil in the soft magnetic powder solution of the first magnetic permeability. magnetic powder solution.
The method of claim 1, wherein applying the soft magnetic powder solution of the first magnetic permeability to the inductor coil includes spraying the soft magnetic powder solution of the first magnetic permeability onto the inductor coil. on the inductor coil.
The method of claim 1, wherein the first thickness is 0.05 mm to 0.1 mm.
The method according to claim 1, characterized in that the predetermined shape is obtained by using a round wire or a flat wire for horizontal winding or vertical winding.
The method according to claim 5, wherein drying the inductor coil of the first structure includes placing the inductor coil of the first structure into an oven and baking it for drying.
The method according to claim 1, wherein drying the inductor coil of the first structure includes drying the inductor coil of the first structure using a hot air gun.
The method according to claim 1, wherein the soft magnetic powder includes at least one of iron silicon chromium powder, iron silicon aluminum powder, carbonyl powder, amorphous powder, nanocrystalline powder, manganese zinc powder and nickel zinc powder. A sort of.
An inductor, characterized in that it is produced based on the method described in any one of claims 1 to 8.
The inductor according to claim 9, wherein the size of the inductor is 1680 or more.