INDUCTOR AND TRANS-INDUCTOR VOLTAGE REGULATOR

An inductor provided in the present invention, includes a magnetic core and one or more conductive coil assembly embedded in the magnetic core; each conductive coil assembly comprises an inner conductive coil and an outer conductive coil coupled to the inner conductive coil. The inner conductive coil and the outer conductive coil are insulated from each other; the inner conductive coil rans through the outer conductive coil whereby most of or all magnetic field lines of the inner conductive coil pass through the outer conductive coil. A trans-inductor voltage regulator provided, includes a circuit board and the inductor electrically connected to the circuit board. The inductor has a coupling coefficient more than 98%.

CROSS REFERENCE TO RELATED APPLICATIONS

The present invention is 35 U.S.C. § 119 benefit of earlier filing dates; rights of priority of Chinese Applications No. 202310877670.0 filed on Jul. 17, 2023, the disclosure of which is incorporated by reference herein.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to the field of electronic components, and more particularly, to an inductor.

Description of Related Art

At present, most traditional coupled inductors are assembled structures, and the materials of the magnetic core generally are ferrite. The magnetic core, conductive coils and coupling are assembled together to obtain the coupled inductor. The assembled inductor is not suitable for trans-inductor voltage regulator (TLVR), and there is a problem of low inductive coupling. The magnetic core and conductive coils cannot be in full contact in the assembled inductor, the power density is low, and the heat dissipation is insufficient.

SUMMARY OF THE INVENTION

An object of the present invention is to is to provide an inductor to solve the problems of low inductive coupling of existing inductors.

An inductor provided by the present invention, comprises a magnetic core, and one or more conductive coil assembly embedded in the magnetic core. Each conductive coil assembly comprises an inner conductive coil and an outer conductive coil coupled to the inner conductive coil. The inner conductive coil and the outer conductive coil are insulated from each other; the inner conductive coil rans through the outer conductive coil whereby most of or all magnetic field lines of the inner conductive coil pass through the outer conductive coil.

Preferably, the inductor is an integrated inductor manufactured by an integrated molding process; the conductive coil assembly is inseparably embedded in the magnetic core.

In some embodiments, a straight channel is formed inside the outer conductive coil and extends to opposite sides of the outer conductive coil and extends to opposite end surfaces of the magnetic core; the outer conductive coil has a main body and opposite leads at opposite sides thereof, the opposite leads extend to said opposite end surfaces of the magnetic core respectively; the inner conductive coil is straight, has a main body and opposite leads at opposite ends thereof, and is inserted in the straight channel in the outer conductive coil, and the opposite leads of the inner conductive coil extend to and said opposite end surfaces of the magnetic core.

In some embodiments, the main body of the outer conductive coil is straight, the straight channel is provided in the straight main body along a length thereof; the inner conductive coil inserted in the straight channel of the outer conductive coil, has the opposite leads thereof passing through the opposite leads of the outer conductive coil and extending to opposite end surfaces of the magnetic core respectively; and the inner conductive coil is parallel to the straight main body of the outer conductive coil. The outer conductive coil is U-shaped or Z-shaped or straight as a whole.

In some embodiments, the opposite leads of the U-shaped outer conductive coil are bent respectively from opposite sides of the main body, extend to opposite end surfaces of the magnetic core, and are exposed on said opposite end surfaces and/or exposed on the same adjacent end surface of said opposite end surface of the magnetic core; and the end surfaces of the magnetic core with the leads thereon is kept flat or planar. The opposite leads of the Z-shaped outer conductive coil are bent respectively from opposite sides of the main body, extend to said opposite end surfaces of the magnetic core, and are exposed on said opposite end surfaces and/or exposed on respective adjacent surfaces of said opposite end surfaces of the magnetic core; and the end surfaces of the magnetic core with the leads thereon is kept flat or planar.

In some embodiments, the inner conductive coil is covered with an insulating layer and/or an inner wall of the straight channel is covered with an insulating layer; the inner conductive coil and the outer conductive coil are insulated from each other by the insulating layer, and the insulating layer provides a spacing between the inner conductive coil and the inner wall of the straight channel close enough whereby a coupling coefficient between the inner conductive coil and the outer conductive coil reaches 0.98 or above.

In some embodiments, insulating magnetic powder is filled between the inner conductive coil and an inner wall of the straight channel to form an insulating layer therebetween which provides electrical insulation and a sufficiently close distance between the inner conductive coil and the outer conductive coil, whereby a coupling coefficient between the inner conductive coil and the outer conductive coil reaches 0.98 or above.

In some embodiments, the magnetic core and the conductive coil assembly are integrated by means of an integrated molding process using magnetic powder filing around the conductive coil assembly in one mold, whereby the magnetic core and the conductive coils are fully contacted and tightly combined; the integrated molding process comprising steps of: a pressing and molding step; and an annealing step.

In some embodiments, the inductor is a multi-phase coupling inductor and comprises multiple conductive coil assemblies embedded in the magnetic core, and each conductive coil assembly includes the inner conductive coil and the outer conductive coil that are coupled to each other.

In some embodiments, each conductive coil assembly is arranged in parallel and spaced apart from each other, and the inner conductive coil and the outer conductive coil are parallel to each other; the inner conductive coils of each conductive coil assembly are electrically connected in series, and the outer conductive coils and corresponding inner conductive coils of each conductive coil assembly are coupled to each other, thereby a high dynamic response is obtained.

In some embodiments, for one multiple conductive coil assembly, which is located at one side of the magnetic core, the outer conductive coil defines an open straight groove along a length thereof, and the inner conductive coil is inserted in the open straight groove; the open straight groove extends to opposite sides of the outer conductive coil and extends to opposite end surfaces of the magnetic core.

In some embodiments, for other multiple conductive coil assemblies, the outer conductive coil defines a straight channel therein along a length thereof, the straight channel extends to opposite sides of the outer conductive coil and extends to said opposite end surfaces of the magnetic core; the outer conductive coil has a straight main body and opposite leads at opposite sides thereof, the opposite leads extend to said opposite end surfaces of the magnetic core respectively; the inner conductive coil is a straight, has a main body and opposite leads at opposite ends thereof, and is inserted in the straight channel in the outer conductive coil, and the opposite leads of the inner conductive coil pass through the opposite leads of the outer conductive coil and extend to said opposite end surfaces of the magnetic core, respectively.

The present invention provides a trans-inductor voltage regulator, comprising a circuit board, and the inductor of any of above-described embodiments which is electrically connected to the circuit board.

The advantages of the present invention are:the inductor of the present invention adopts an inner conductive coil is inserted through an outer conductive coil, the inner and outer conductive coils are embedded in the magnetic core by means of integrated molding, thereby, a very high coupling coefficient is obtained. The coupling coefficient can be more than 0.98, that's almost a full coupling, thus a fast response of the inductor is obtained and the powder loss is reduced.

In some embodiments, the inductor of the present invention, the magnetic core and the conductive coils are integrated into inseparable one piece, magnetic powder fully fill gaps in the magnetic core and between the conductive coils, which improves the magnetic permeability and magnetic flux density of the inductor, and reduces the powder loss. The magnetic core and conductive coils are tightly combined, and have good heat conduction and heat dissipation effects, which can keep the inductor at a lower operating temperature. The magnetic core and conductive coils are molded in one piece to give the inductor a high density.

DETAILED DESCRIPTION OF THE INVENTION

An integrated inductor is described herein. Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, the present invention may be implemented in various forms and should not be limited to the embodiments described below. Rather, these embodiments are provided to enable those skilled in the art to completely understand the present invention.

Certain terminology is used in the following description for convenience only and is not limiting. The words “a”, “an” and “one”, as used in the claims and in the corresponding portions of the specification, are defined as including one or more of the referenced items unless specifically stated otherwise. This terminology includes the words above specifically mentioned, derivatives thereof, and words of similar import. The phrase “at least one” followed by a list of two or more items, such as “A, B, or C,” means any individual one of A, B or C as well as any combination thereof. It may be noted that some Figures are shown with partial transparency for the purpose of explanation, illustration and demonstration purposes only, and is not intended to indicate that an element itself would be transparent in its final manufactured form.

Although the terms first, second, etc. may be used herein to describe various elements, components, regions, layers and/or sections; these elements, components, regions, layers and/or sections shall not be referred to as limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, an element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

For ease of description, orientational terms may be used herein to describe the relationship of one element or feature to another element or feature as shown in the figures, such as “internal”, “external”, “inside”, “outside”, “below”, “beneath”, “under”, “above”, “on”, “top”, “bottom”, “front”, “rear”, “left”, “right”, etc. Such orientational terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures and description. For example, if the device in the figures is turned over, elements described as “below” or “beneath” or “under” other elements or features would then be oriented “above” or “on” the other elements or features. Thus, the example term “below” may include an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the orientation herein should be interpreted accordingly.

The experimental methods described in the following examples, if no special limitations are given, are conventional methods; the reagents and materials, if no special limitations are given, can be obtained from commercial sources.

Numerical values or value ranges disclosed herein are not limited to the precise values or range, but should be understood to include values approaching these ranges or values. For numerical ranges, the endpoints and any point values within the range, individual or combined with each other to obtain one or more new value ranges, shall be deemed to be specifically disclosed herein.

Referring toFIGS.1-17, an integrated inductor100of the present invention includes a magnetic core10and one or more coupled conductive coil assembly20embedded inside the magnetic core10. The integrated inductor100can be single-phase coupled or multi-phase coupled, where the single-phase inductor has one or more pair of conductive coils in the magnetic core10, and the multi-phase inductor has multiple pair of conductive coils in the magnetic core10. Each conductive coil assembly20includes an inner conductive coil21and an outer conductive coil22which are coupled to each other. The inner conductive coil21is longitudinally inserted in and rans through the outer conductive coil22. The inner conductive coil21comprises a main body and opposite leads210,211at opposite ends of the coil21(or at opposite ends of the main body), and the outer conductive coil22comprises a main body and opposite leads220,221at opposite sides of the coil22(or at opposite sides of main body), the main body of the inner conductive coil21is encapsuled inside the main body of the outer conductive coil22. Surfaces of the inner conductive coils21and/or the outer conductive coils22are covered with a thin insulating layer, or a spacing between the conductive coils21and22is filled with insulating magnetic powder (particles), thus the inner conductive coil21is electrically insulated from the outer conductive coil22. The inner conductive coil21is entirely inside the outer conductive coil22along a length direction, almost all magnetic lines of the inner conductive coil21pass through the outer conductive coil22, therefore, a coupling coefficient between the coils21and22makes the inductor100work as an omni (full) coupled inductor, that is, the coupling coefficient is close to 1. A distance between the two conductive coils21and22is close enough to obtain such high coupling coefficient to an omni coupling. The coupling coefficient can be 0.98 or above, and close to 1, and a fast response can be obtained. Since a distance between the inner conductive coil21and the outer conductive coil22is close enough, further, the inner conductive coil21is encapsuled/inserted inside the outer conductive coil22, therefore, almost all magnetic field lines of the inner conductive coil21passes through the outer conductive coil22, which results a high coupling coefficient.

In some specific embodiments, a straight channel223is formed in the outer conductive coil22, ran through a length of the coil22, and extend to opposite end surfaces11,11′ of the magnetic core10. The leads220,221at opposite sides of the outer conductive coil22are exposed on end surface(s) of the magnetic core10for facilitating electrical connection with a circuit on a circuit board. Generally, the end surface(s) of the magnetic core with leads220,221thereon keeps flat or planar. The inner conductive coil21is straight-out or straight, and is inserted in and ran through the straight channel223in the outer conductive coil. The opposite leads210and211at opposite ends of the inner conductive coil21extend to and are exposed on opposite end surfaces11and11′ of the magnetic core10for facilitating electrical connection with the circuit on the circuit board.

The outer conductive coil22includes a linear main body, and the straight channel223rans though the linear main body along a length direction thereof. The inner conductive coil21is inserted in the straight channel223and is parallel to the linear main body of the outer conductive coil22. The inner conductive coil21passes through the straight channel223in the outer conductive coil22, and the straight leads210and211of the coil21respectively pass through the leads220and221of the outer conductive coil22and extend out of opposite end surfaces11and11′ of the magnetic core10.

Surfaces of the conductive coil21,22or a spacing between the conductive coils is covered with a thin insulating layer, or is insulated by insulating magnetic particles. Specifically, the surface of the inner conductive coil21is covered with a thin insulating layer, and/or an inner wall of the straight channel223of the outer conductive coil22is covered with a thin insulating layer thereon. The thin insulating layer insulates and separates the inner conductive coil21from the inner wall of the straight channel223in the outer conductive coil22, thus a distance between the inner conductive coil21and the inner wall of the straight channel223is close enough and the coupling coefficient between the inner and outer conductive coils21and22reaches more than 0.98. In other embodiments, the thin insulating layer may be formed by insulating soft magnetic powder (particles), so that the distance between the inner conductive coil21and the inner wall of the straight channel223is close enough.

In some embodiments, the integrated inductor100is a multi-phase coupling inductor, and multiple coupled conductive coil assemblies20are embedded in the magnetic core10. Each conductive coil assembly20includes the inner and outer conductive coils21,22that are coupled to each other; The conductive coil assemblies20are arranged parallel and spaced apart from each other, and the inner and outer conductive coils21,22are parallel to each other. The inner conductive coils21are electrically connected in series with each other, and the outer conductive coil22of each conductive coil assembly20is coupled to the corresponding inner conductive coil21therein, thereby a highly dynamic response is obtained.

In some embodiments, in the multi-phase coupled inductor100, for a higher coupling between conductive coil assemblies20and eliminating interference, one outermost conductive coil assembly20is configured that:

an open straight groove224is formed on a surface of the outer conductive coil22along a length thereof, and extend to opposite ends of the outer conductive coil22and opposite end surfaces11,11′ of the magnetic core10, the leads220and221at opposite sides of the outer conductive coil22are exposed on opposite end surface11,11′ of the magnetic core10;

the inner conductive coil21is inserted and rans through the open straight groove224of the outer conductive coil22, and the leads210and211of the coil21respectively pass through the leads220and221of the outer conductive coil22and extend out of opposite end surfaces11and11′ of the magnetic core; andthere is a sufficiently close distance or spacing between the inner conductive coil21and the outer conductive coil22. In some embodiments, a thin insulating layer covering on an inner wall of the straight groove224and/or on the outer surface of the inner conductive coil21to obtain an enough close distance and electrically insulation between the coils21and22when the inner conductive coil21is inserted in the outer conductive coil22. In other embodiments, fill soft magnetic powder between the coils21and22to form a thin insulating layer, thus obtain an enough close distance and electrically insulation therebetween, thereby a high coupling between the inner and outer conductive coil21and22is obtained.

In a preferred embodiment, the outer conductive coil22, comprising the main body and opposite leads220and221on opposite sides of the main body, is “U”-shaped or “Z”-shaped or straight-out (straight). The pair of leads220and221of the outer conductive coil22are bent from opposite sides of the main body and exposed on the end surfaces of the magnetic core10respectively, and the end surfaces with the leads220,221thereon of the magnetic core10is kept flat or planar. The inner conductive coil21is a straight (such as a straight rod). The inner conductive coil21is completely inserted into or completely placed in the outer conductive coil22. Opposite straight leads210and211extend out of opposite surfaces, that is, the first end surfaces11/11′ of the magnetic core10.

In one exemplary embodiment, the magnetic core10and the conductive coil assembly20can be formed into an integrated structure by means of a molding process by filling magnetic powder around the conductive coil assembly20in a mold. The molding process comprises the following steps:pressing and molding step, specifically: installing conductive coil assembly(s)20in a mold with the inner conductive coil21inserted into the outer conductive coil22, filling the mold cavity with magnetic powder, applying pressure for molding, where the molding pressure can be 12˜24 T/cm2, then obtaining a raw inductor of which the conductive coils are embedded in the magnetic core and the leads are exposed on the surface(s) of the magnetic core; andannealing step: placing the raw inductor in a heat treatment furnace for calcinating and annealing so as to release residual stress inside the magnetic core, and obtaining the integrated inductor with a high dynamic response, where annealing temperature can be 400˜850° C.

Magnetic powder is insulating magnetic powder (particles), and the insulating magnetic powder can be one or more of Fe-based powder, Fe—Si powder, Fe—Si—Al alloy powder, Fe—Ni alloy powder, etc., or amorphous powder thereof.

During the molding process, soft magnetic powder is filled around conductive coils in the mold, soft magnetic powder material is evenly distributed between the conductive coils and make the conductive coils electrically insulated from each other. The magnetic core and conductive coils fully contact to obtain a rapid heat transfer. The molding process at a high-pressure (12˜24 T/cm2) significantly reduces gaps inside the inductor (or inside magnetic core), through which an inductor can be obtained with full space utilization and at a high-power density. A multi-phase integrated inductor with a high dynamic response can be manufactured by means of molding soft magnetic powder filled around multiple conductive coils in one mold, which can save a volume of the inductor. The inductor of the present invention has a small profile and high-power density.

Referring toFIGS.1-3, the integrated inductor100in accordance with a first embodiment includes a square (not limited to square) magnetic core10and a conductive coil assembly20embedded in the magnetic core10. The conductive coil assembly20includes an inner conductive coil21and an outer conductive coil22. The inner conductive coil21is straight-out (straight), is completely built-in the outer conductive coil22, rans through the outer conductive coil22, and is parallel to the outer conductive coil22along a length direction thereof. Opposite leads210,211of the inner conductive coil21extend outwards from opposite leads220,221of the outer conductive coil22respectively and are exposed on opposite end surfaces11,11′ of the magnetic core10. The straight channel223is define in the outer conductive coil22and along a length direction thereof. The inner conductive coil21is inserted in the straight channel223. Through an integrated molding process using magnetic powder and the conductive coils21,22, the insulating magnetic powder material is evenly distributed between the conductive coils, thus the conductive coils21and22are sufficiently close together and electrically insulated from each other, there is almost no gap inside the inductor (or in the magnetic core), thereby the inner and outer conductive coils21and22represent a very high coupling coefficient such as 0.98 or above, near a complete coupling. Alternatively, the inner conductive coil21is covered with an insulating layer, is inserted into the straight channel223, and is electrically insulated from the outer conductive coil22. The outer conductive coil22, comprising a main body and opposite leads220and221at opposite sides thereof, is U-shaped as a whole. The main body of the outer conductive coil22is linear, specifically is straight. The lead220is bent to and exposed on two adjacent end surfaces11and12of the magnetic core10. The other lead221is bent to and exposed on the two adjacent end surfaces11′ and12of the magnetic core10, and the end surfaces11and11′ are opposite to each other. The leads220and221are embedded in the end surface for keeping the end surfaces flat or planar. A conductive coating may be formed on the end surfaces for electrically connected with the leads220and221respectively for facilitating electrically connected with the circuit of the circuit board.

Referring toFIGS.4-6, the integrated inductor100in accordance with a second embodiment, includes the square (not limited to square) magnetic core10and the conductive coil assembly20embedded in the magnetic core10. The conductive coil assembly20includes a pair of inner and outer conductive coils21and22. The inner conductive coil21is a straight out or straight conductive coil, completely built in the outer conductive coil22, and parallelly inserted into the linear main body of the outer conductive coil. The opposite leads210,211of the inner conductive coil21respectively extend outwards from the opposite leads220,221of the outer conductive coil22and are exposed on opposite end surfaces11,11′ of the magnetic core10. The outer conductive coil22inside forms the straight channel223, and the straight inner conductive coil21is inserted into the straight channel223. The gap between the inner conductive coil and the inner wall of the straight channel223is filled with magnetic powder to form a thin insulating layer. The conductive coils21and22and the magnetic core10are integrated by means the integrated molding process. Insulating magnetic powder material is evenly distributed between the conductive coils, so that the conductive coils21and22form the closest distance therebetween and are electrically insulated from each other. There is almost no gap inside the inductor, a complete/full coupling is obtained between the inner and outer conductive coils21and22, and the coupling coefficient exceeds 0.98. Alternatively, the surface of the inner conductive coil21is covered with an insulating layer, is inserted in the straight channel223, and is electrically insulated from the outer conductive coil22. The outer conductive coil22, comprising a main body and opposite leads220and221at opposite sides thereof, is Z-shaped as a whole. The main body of the outer conductive coil22is linear, specifically is straight. The lead220is bent from the main body and exposed on the two adjacent end surfaces11and12of the magnetic core10. The other lead221is bent from the main body and is exposed on the two adjacent end surfaces11′ and12′ of the magnetic core10. The end surfaces11and11′ are opposite to each other, and the end surfaces12and12′ are opposite to each other. The leads220and221are embedded in the end surfaces and keep the end surfaces flat or planar. The leads220and221can be electrically connected and expanded by covering a conductive coating on the end surfaces of the magnetic core10.

In other embodiments, the outer conductive coil22can be a straight-out or straight conductive coil, embedded in the magnetic core10, ran through the magnetic core and expend outwards from opposite end surfaces11/11′ of the magnetic core10. The opposite leads220,221are exposed on or extend out of opposite end surfaces11/11′ of the magnetic core10. The straight channel223rans through inside the straight outer conductive coil22along a length thereof, and the inner conductive coil21is inserted into the straight channel223with the opposite leads210and211extending out of opposite end surfaces11/11′ of the magnetic core10.

Referring toFIGS.7-9, the integrated inductor100in accordance with a third embodiment includes the square (not limited to square) magnetic core10and multiple conductive coil assemblies20embedded in the core10to form a multi-phase coupling integration. As shown in the figure, two conductive coil assemblies20are arranged in parallel and spaced apart in the magnetic core10, and the inner and outer conductive coils21and22are parallel to each other. Each conductive coil assembly20includes a pair of inner and outer conductive coils21and22. The inner conductive coil21is a straight-out or straight conductive coil, completely built in the outer conductive coil22, and is inserted into the outer conductive coil in parallel along the length direction. The opposite leads211,210extend outwards from the outer conductive coil to the opposite surfaces11,11′ of the magnetic core10. A straight channel223is formed in the outer conductive coil22, runs through the coil22and extends to opposite end surfaces11,11′ of the magnetic core10along the length direction. The straight inner conductive coil21is inserted into the straight channel223. The gap between the inner wall of the straight channel223and the straight inner conductive coil21is filled with insulating magnetic powder to form a thin insulating layer. Insulating magnetic powder and the conductive coils21and22are integrated by means of an integrated molding process. The insulating magnetic powder material is evenly distributed between the conductive coils, so that the conductive coils21and22are spaced as a closest distance and electrically insulated from each other. There is almost no gap inside the inductor, so that almost a full coupling is formed between the inner and outer conductive coils21and22, and the coupling coefficient exceeds 0.98. Alternatively, the surface of the inner conductive coil21is covered with a thin insulating layer, is inserted into the straight channel223, and is electrically insulated from the outer conductive coil22. The outer conductive coil22, comprises a main body and opposite leads220and221at opposite sides thereof, is a C-shaped or U-shaped as a whole. The main body of the outer conductive coil22is linear, with a straight channel223formed inside; the lead220is bent from the main body and embedded in the two adjacent end surfaces11and12of the magnetic core10. The other lead221is bent from the main body and embedded in two adjacent end surfaces11′ and12of the magnetic core10. The end surfaces11and11′ are opposite to each other. The leads220and221are embedded in the end surfaces and are exposed on the end surfaces to keep the end surfaces flat or planar. The leads220and221may also be electrically connected and covered respectively by a conductive coating covered on the end surfaces of the magnetic core10for facilitating electrical connection to the circuit board.

Referring toFIGS.10-13, the integrated inductor100in accordance with a fourth embodiment includes the square (not limited to square) magnetic core10and multiple conductive coil assemblies20embedded in the magnetic core10to form a multi-phase coupling integration. As shown in the figures, three conductive coil assemblies20are arranged in parallel and spaced apart in the magnetic core10, and the inner and outer conductive coils21and22are parallel to each other. Each conductive coil assembly20includes a pair of inner and outer conductive coils21and22. The outer conductive coil22, comprises a main body and opposite leads220and221, is U-shaped as a whole. The main body of the outer conductive coil22is linear or straight. The two adjacent outer conductive coils22, namely one outermost and middle coils22, respectively form a straight channel223inside along a length thereof; while the other conductive coil22, that is the other outermost coil22, forms an open straight groove224on its surface away from the other coils22along a length thereof; and the straight channel223and the open straight groove224extend to opposite end surfaces11,11′ of the magnetic core10. For each conductive coil assembly20, the lead220is bent from the main body of the outer conductive coil22and embedded in two adjacent end surfaces11and12of the magnetic core, while the other lead221is bent from the main body and embedded in the two adjacent end surfaces11′ and12of the magnetic core10. The end surfaces11and11′ are opposite to each other. The leads220and221are embedded in the end surfaces, exposed on the end surfaces and keep the end surfaces flat or planar. The leads220and221may be electrically connected with and covered by a conductive coating on the end surfaces, respectively. The inner conductive coil21is a straight-out conductive coil, and is inserted parallelly along the length direction into the straight channel223defined in the outer conductive coil22or is inserted into the open straight groove224formed on the surface of the outer conductive coil22. The opposite straight leads211,210of the inner conductive coil21respectively extend outwards from the leads220,221of the outer conductive coil22and extend outwards from the opposite surfaces11,11′ of the magnetic core10. The straight inner conductive coil21is inserted into the straight channel223inside the outer conductive coil22or inserted into the open straight groove224on the surface of the outer conductive coil22. The gap between the inner conductive coil and the inner wall of the straight channel223/open straight groove224is filled with magnetic powder to form a thin insulating layer. The magnetic powder and the conductive coils21and22are integrated together. The insulating magnetic powder material is evenly distributed between the conductive coils, so that the conductive coils21and22is spaced at the closest distance and electrically insulated from each other. There is almost no air gap inside the inductor or the magnetic core. The inner and outer conductive coils21and22are completed coupled to each other, and the coupling coefficient exceeds 0.98. Alternatively, the surface of the inner conductive coil21is covered with an insulating layer, is inserted into the straight channel223and insulated from the outer conductive coil22.

This embodiment takes three-phase coupling as an example to illustrate the principle of multi-phase coupling. The first, second, and third (or more) inner conductive coils can be electrically connected in series, the first outer conductive coil is coupled to the first inner conductive coil, and the coupling signal (current and voltage) formed in the first inner conductive coil must flow through the second and third inner conductive coils. Moreover, the second inner and outer conductive coils are fully coupled to each other, and the third inner and outer conductive coils are fully coupled, thus a high response is obtained.

Referring toFIGS.14-17, the integrated inductor100in accordance with a fifth embodiment includes the square (not limited to square) magnetic core10and multiple conductive coil assemblies20embedded in the magnetic core10to form a multi-phase coupling integration. As shown in the figures, three conductive coil assemblies20are arranged in parallel and spaced apart in the magnetic core10, and the inner and outer conductive coils21and22are parallel to each other. Each conductive coil assembly20includes a pair of inner and outer conductive coils21and22. The outer conductive coil22having a main body and opposite leads220and221, is Z-shaped as a whole. The main body of the outer conductive coil22is linear or straight. The two adjacent outer conductive coils22at one outermost side and the middle position, respectively form a straight channel223inside along a length direction thereof, while the conductive coil22on the other outmost side forms an open straight groove224on its surface away from the other two outer conductive coils22. The straight channel223and the open straight groove224extend to opposite end surfaces11,11′ of the magnetic core10. The lead220of each outer conductive coil22is bent from one side of the main body and extends to the two adjacent end surfaces11and12of the magnetic core, and the other lead221is bent from the opposite side of the main body and extends to the two adjacent end surfaces11′ and12′ of the magnetic core. The end surfaces11and11′ are opposite to each other. The end surfaces12and12′ are opposite to each other. The leads220and221are embedded in the end surfaces, exposed on the end surface and keep the end surfaces flat or planar. The leads220and221may be electrically connected and covered respectively by a conductive coating on the end surfaces of the magnetic core for facilitating electrical connection with the circuit board. The inner conductive coil21is a straight-out conductive coil, and is inserted parallelly along the length direction into the straight channel223formed in the outer conductive coil or inserted into the open straight groove224formed on the surface of the outer conductive coil. The leads211,210respectively extend outwards from the leads220,221of the conductive coil22and extend outwards from opposite end surfaces11,11′ of the magnetic core10. The straight inner conductive coil21is inserted into the straight channel223or the straight groove224. The gap between the inner conductive coil and the inner wall of the straight channel223/straight groove224is filled with insulating magnetic powder to form a thin insulating layer. The magnetic powder and the conductive coils21and22are integrated together by means of the integrated molding process. The insulating magnetic powder material is evenly distributed between the conductive coils, so that the conductive coils21and22are spaced at the closest distance and electrically insulated from each other. There is almost no air gap inside the magnetic core10. The inner and outer conductive coils21and22is fully coupled, and the coupling coefficient exceeds 0.98. Alternatively, the surface of the inner conductive coil21is covered with a thin insulating layer, is inserted into the straight channel223/open straight groove224and is electrically insulated from the outer conductive coil22.

This embodiment takes three-phase coupling as an example to illustrate the principle of multi-phase coupling. The first, second, and third (or more) inner conductive coils are electrically connected in series, and the first outer conductive coil is coupled to the first inner conductive coil, the coupling signal (current and voltage) formed in the first inner conductive coil must flow through the second and third inner conductive coils. Moreover, the second inner and outer conductive coils are fully coupled to each other, and the third inner and outer conductive coils are fully coupled, thus a high response is obtained.

The integrated inductor100of the present invention is used as an inductor for a trans-inductor voltage regulator (TLVR). The TLVR comprise a circuit board, and the inductor100is electrically connected with a circuit in the circuit board.

In the integrated inductor100of the present invention, one or more conductive coil assemblies20are embedded in the magnetic core10. The integrated inductor100can be single-phase coupling or multi-phase coupling. The straight-out inner conductive coil21is built-in the outer conductive coil22along a length direction thereof. When it is multi-phase coupled inductor, the outermost inner conductive coil21is embedded in an open groove224on the surface of the corresponding outer conductive coil22. A spacing between the inner conductive coil21and the outer conductive coil22of each conductive coil assembly20is close enough so as to obtain a very high coupling, such as the coupling coefficient can be 0.98 or above, and the inductor100is nearly an omnicoupled (full coupling) inductor, and has a fast response. Through high-pressure molding of soft magnetic powder (particles) and conductive coils in one mold, the insulating magnetic powder (particle) material is evenly distributed between the conductive coils, thereby, the inner conductive coil21and the outer conductive coil22are spaced at the closest distance and are insulated from each other. There is almost no air gap inside the entire inductor100(or magnetic core10) to obtain full space utilization and high-power density. The magnet core10and conductive coils21,22are fully contacted and closely combined to realize rapid heat transfer and good heat dissipation effect, which keeps the inductor at a lower operating temperature. The inductor100of the present invention is simpler for manufacturing and applicable for SMD packaging, therefore, it is easy to realize an automagical manufacturing process, and the manufacturing method for the inductor and the inductor are low-cost. The integrated inductor of the present invention can be integrated with single or multiple phases to obtain a small size with high power density. The inductor in accordance with some embodiments of the present invention is formed by integrating the magnetic core made of soft magnetic powder (particles) and conductive coils in one mold, the entire closed magnetic path of the inductor is provided by the magnetic materials, and there is no obvious air gap in the inductor or in the magnetic core; therefore, the integrated inductor provided by the present invention obtains magnetic shield, which represents an anti-electromagnetic interference function.

The technical features of the above embodiments can be combined arbitrarily. In order to make the description simple, all possible combinations of the technical features in the above embodiments are not described. However, as long as there is no contradiction in the combination of these technical features It is considered to be the range described in this specification.

The above examples only represent several embodiments of the present invention, and the descriptions thereof are specific and detailed, but should not be construed as a limitation on the scope of the invention patent. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can also be made, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.