Inductor and method for manufacturing the same

Abstract

The present invention provides an inductor and a manufacturing method thereof, wherein a columnar portion is formed around a winding before the inductor is formed, so as to prevent the winding from being subjected to a large pressure during the inductor forming process, thereby preventing a short circuit caused by excessive pressure. The inductor comprises a body and a winding; the winding body is buried in the body, and both ends extend out of the body and form electrodes on the surface of the body; the body comprises a first part, a second part and a third part; the first part is a cylindrical structure, and the winding is closely attached to the outer surface of the first part; the second part is a cylindrical structure concentric with the first part; the second part is directly formed on the first part and the winding; the third part is directly formed on the second part.

Description

Technical Field

[0001] The invention relates to a passive electronic component, and in particular to an inductor and a manufacturing method thereof. Background Art

[0002] Inductors are a basic passive electronic component, widely used in various electronic circuits. Among them, one-piece molded inductors have gradually become mainstream due to their excellent characteristics and small size. Existing one-piece molded inductors are mostly formed by putting the winding on a combination of multiple pre-formed magnetic cores and then filling them with powder and pressing them. Common pre-formed magnetic cores include T-type, U-type, E-type, I-type, etc. The pressure during pressing is very high, reaching tens of tons. The winding directly bears such a huge pressure, which can easily cause the surface insulation layer to break, thereby causing a short circuit. If the above problem is not solved, the thickness or hardness of the surface insulation layer of the winding will usually be increased, but it will affect the wire diameter of the winding, thereby limiting the number of turns of the winding in a certain space. Summary of the invention

[0003] The present invention provides an inductor, in which a columnar part is formed around a winding before the inductor is formed, so as to avoid the winding being subjected to a large pressure during the inductor forming, thereby avoiding a short circuit caused by excessive pressure.

[0004] The present invention provides an inductor, comprising a body and a winding; the winding body is buried in the body, with two ends extending out of the body and forming electrodes on the surface of the body; the body comprises a first part, a second part and a third part; the first part is a cylindrical structure, and the winding is tightly attached to the outer surface of the first part; the second part is a cylindrical structure concentric with the first part; the second part is directly formed on the first part and the winding; the third part is directly formed on the second part.

[0005] Furthermore, the main body also includes a fourth part formed by cold pressing, hot pressing and / or sintering of magnetic powder; the fourth part is provided with a groove which is gap-matched with the first part.

[0006] Furthermore, when viewed in a direction perpendicular to the axial direction of the first part, the first part includes a plurality of molded parts sequentially formed along the axial direction of the first part; and the plurality of molded parts have different magnetic permeabilities.

[0007] Furthermore, when viewed along a direction perpendicular to the radial direction of the first part, the first part includes a plurality of formed parts sequentially formed along the radial direction of the first part; and the plurality of formed parts have different magnetic permeabilities.

[0008] The present invention also provides a method for manufacturing the above-mentioned inductor, comprising the following steps: S1, preparing a cylindrical first part; S2, winding a winding on the first part to obtain a winding forming module; S3, forming a second part of the winding wrapped around the winding forming part to obtain a wrapped molding module; S4, filling magnetic powder around the wrapped molding module and forming electrodes to obtain an inductor.

[0009] Furthermore, the second part is a cylinder concentric with the first part; the second part is formed by pressing the magnetic powder under a force perpendicular to the axial direction of the first part.

[0010] Furthermore, step S4 includes placing the overmolded module into a mold, filling the mold with magnetic powder, compacting and / or sintering the mold to form a semi-finished product, and forming electrodes on the surface of the semi-finished product to obtain an inductor.

[0011] Furthermore, step S4 further includes preparing the fourth part, combining the fourth part with the overmolding module and placing it into a mold, filling magnetic powder and then compacting and / or sintering to form a semi-finished product, and forming electrodes on the surface of the semi-finished product to obtain an inductor.

[0012] Furthermore, the step S1 includes S11, compacting and / or sintering the magnetic powder to form a first molding part; S12, placing the first molding part in a mold, filling it with powder and compacting it to form a second molding part on the first molding part; S13, continuing to fill it with powder to form a third molding part on the second molding part.

[0013] The beneficial effects of the present invention are as follows: before the inductor is integrally formed, the second part is first formed around the winding with a relatively small pressure, so that the pressure directly applied to the winding when the inductor is integrally formed can be avoided, so that the insulating layer on the surface of the winding does not need to be thickened and is not prone to short circuit; because the second part is columnar, the pressure at various locations is balanced when the second part is formed, so that each turn of the winding is evenly stressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a cross-sectional schematic diagram of an inductor according to Embodiment 1;

[0015] Figure 2 It is a schematic diagram of the structure of the winding forming module;

[0016] Figure 3 It is a schematic diagram of the structure of the overmolding module;

[0017] Figure 4 is a cross-sectional schematic diagram of an overmolding module;

[0018] Figure 5 is a cross-sectional schematic diagram of an inductor according to Embodiment 2;

[0019] Figure 6This is a cross-sectional schematic diagram of the winding forming module of Example 3;

[0020] Figure 7 This is a cross-sectional schematic diagram of the winding forming module of Example 4.

[0021] Marked in the figure: 101, electrode; 110, first part; 111, first molded part; 112, second molded part; 113, third molded part; 114, fourth molded part; 111B, first molded part; 112B, second molded part; 113B, third molded part; 120, second part; 130, third part; 140, fourth part; 200, winding. DETAILED DESCRIPTION

[0022] In order to deepen the understanding of the present invention, exemplary embodiments will be described in detail here, and examples thereof are shown in the accompanying drawings. When the following description refers to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application.

[0023] The terms used in this application are only for the purpose of describing specific embodiments and are not intended to limit this application. Unless otherwise defined, the technical terms or scientific terms used in this application should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in this application do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one" or "one" do not indicate quantity restrictions, but indicate the existence of at least one. "Multiple" or "several" means two or more. Unless otherwise specified, words such as "front", "rear", "lower" and / or "upper" are only for the convenience of explanation and are not limited to one position or one spatial orientation. Words such as "include" or "comprise" mean that the elements or objects appearing in front of "include" or "comprise" include the elements or objects listed after "include" or "comprise" and their equivalents, and do not exclude other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, and can include electrical connections, whether direct or indirect. As used in this specification and the appended claims, the singular forms "a", "an", "said" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and encompasses any or all possible combinations of one or more of the associated listed items.

[0024] Embodiment 1

[0025] Please refer to Figures 1 to 4The present invention provides an inductor, comprising a body and a winding 200; the winding 200 is buried in the body, with two ends extending out of the body and electrodes 101 formed on the surface of the body; the body comprises a first part 110, a second part 120 and a third part 130; the first part 110 is a cylindrical structure, the winding 200 is directly wound on the first part 110, and the winding 200 is closely attached to the outer surface of the first part 110; the second part 120 is a cylindrical structure concentric with the first part 110, and the second part 120 is directly formed around the winding 200 by molding, which can prevent the winding 200 from being directly subjected to pressure during subsequent pressing and forming, thereby protecting the winding 200; the third part 130 is directly pressed and formed on the basis of the second part 120. Since the second part 120 is a columnar structure, its radial pressure distribution is more uniform than that of a square structure. Therefore, when the second part 120 is press-formed, a pressure smaller than that of the third part 130 can be used, thereby reducing the pressure directly borne by the winding 200. Therefore, the insulating layer on the surface of the winding 200 does not need to be thickened and is not prone to short circuit. On the other hand, the winding 200 is directly wound on the first part 110. When the second part 120 is formed, the first part 110 can provide radial support for the winding 200 to prevent radial deformation of the winding 200 after being compressed.

[0026] Embodiment 2

[0027] Please refer to Figure 5 The difference between this embodiment and the first embodiment is that the body further includes a fourth part 140, and the fourth part 140 is formed by cold pressing, hot pressing and / or sintering of magnetic powder; the fourth part 140 is provided with a groove that is gap-matched with the first part 110, and before the third part 130 is formed, the first part 110 is first placed in the groove on the fourth part 140, and then the first part 110, the second part 120, the third part 130 and the fourth part 140 are pressed and fused together by pressing, and the third part 130 is formed in this process.

[0028] Embodiment 3

[0029] Please refer to Figure 6 The difference between this embodiment and the first embodiment is that the first part 110 includes a plurality of molding parts. When viewed in a direction perpendicular to the axial direction of the first part 110, the first part 110 includes a first molding part 111, a second molding part 112, a third molding part 113 and a fourth molding part 114 sequentially formed along the axial direction of the first part 110. The magnetic permeabilities of the plurality of molding parts are different, which can improve the final characteristic value μ of the inductor. The first part 110 of this embodiment includes four molding parts, which are formed by four times of powder filling and pressing. In other embodiments, there may be two, three, five or even more molding parts.

[0030] Embodiment 4

[0031] Please refer to Figure 7 The difference between this embodiment and the third embodiment is that a plurality of molding parts are sequentially formed along the radial direction of the first part 110. Observed in a direction perpendicular to the radial direction of the first part, the first part includes a first molding part 111B, a second molding part 112B and a third molding part 113B sequentially formed along the radial direction of the first part; the first part 110 of this embodiment includes three molding parts, which are formed by three times of powder filling and pressing, and in other embodiments, there may be two, four or even more molding parts.

[0032] The present invention also provides a method for manufacturing the above-mentioned inductor, comprising the following steps:

[0033] S1. Prepare the first part: first prepare a cylindrical first part 110,

[0034] S2, preparing a winding forming module: directly winding a coil on the first part 110, so that the winding 200 is closely attached to the surface of the first part 110, and obtaining a winding forming module ( Figure 2 );

[0035] S3, preparing the overmolded module: forming the second part 120 around the winding 200 by powder filling and pressing, so that the second part 120 completely covers the winding 200, and obtaining the overmolded module ( Figure 3 );

[0036] S4, inductor molding: Finally, a soft magnetic material is coated on the outside of the overmolding module and an electrode 101 is formed on the surface to obtain an inductor.

[0037] The first portion 110 may be prepared by cold pressing, hot pressing or sintering. The first portion 110 may have a plurality of formed portions with different magnetic permeabilities to improve the characteristic value of the inductor.

[0038] In actual operation, the second part 120 can be formed by pressing magnetic powder along the radial direction of the winding 200 by two curved molds. The second part 120 is cylindrical and concentric with the first part 110. Since the first part 110 provides radial support for the winding 200, the winding 200 will not be radially deformed during this process. The second part 120 is used to protect the winding 200 to prevent the winding 200 from being directly subjected to a large pressure when the final inductor is formed. After the second part 120 is formed, it can be baked to initially solidify its interior to increase its hardness.

[0039] When forming the inductor, the overmolding module can be placed in the mold, and the mold can be filled with magnetic powder and compacted and / or sintered; the overmolding module can also be assembled with the prefabricated fourth part 140 and then placed in the mold, and then pressed and / or sintered, and finally the electrode is formed on the surface. The fourth part can be a soft magnetic material or a metal material, which can be integrated with the first part 110, the second part 120 and the third part 130, and can also be used as a shielding layer to enhance the electromagnetic shielding performance of the inductor.

[0040] The above is only a preferred embodiment of the present application and does not constitute any form of limitation on the present application. Although the present application has been disclosed as a preferred embodiment as above, it is not intended to limit the present application. Any technician familiar with the profession can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present application. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application still falls within the scope of the technical solution of the present application.

Claims

1. An inductor, comprising a body and a winding; the winding body is buried in the body, with two ends extending out of the body and forming electrodes on the surface of the body; characterized in that: The body comprises a first part, a second part and a third part; the first part is a cylindrical structure, and the winding is closely attached to the outer surface of the first part; the second part is a cylindrical structure concentric with the first part; the second part is directly formed on the first part and the winding, and the pressure used when the second part is pressed is smaller than that when the third part is pressed; the third part is directly formed on the second part; The body further comprises a fourth part formed by cold pressing, hot pressing and / or sintering of magnetic powder; the fourth part is provided with a groove which is gap-matched with the first part; When viewed in a direction perpendicular to the axial direction of the first part, the first part includes a plurality of molded parts formed in sequence along the axial direction of the first part; the plurality of molded parts have different magnetic permeabilities; Or, when viewed along a direction perpendicular to the radial direction of the first portion, the first portion includes a plurality of formed portions formed sequentially along the radial direction of the first portion; and the plurality of formed portions have different magnetic permeabilities.

2. A method for manufacturing the inductor as claimed in claim 1, characterized in that: The following steps are involved: S1, preparing a cylindrical first part; S2, winding a winding on the first part to obtain a winding forming module; S3, forming a second part of the wrapped winding around the winding forming part to obtain an overmolded module; the second part is a cylinder concentric with the first part; the second part is formed by pressing the magnetic powder with a force perpendicular to the axial direction of the first part; S4, filling magnetic powder around the overmolded module, forming a third part on the second part, and forming an electrode The step S4 further includes preparing the fourth part, combining the fourth part with the overmolding module and placing them into a mold, filling magnetic powder, compacting and sintering to form a semi-finished product, and forming electrodes on the surface of the semi-finished product to obtain an inductor; The second portion is formed directly on the first portion and the winding, and the second portion is pressed and formed using a pressure that is less than that used when the third portion is formed.

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