CN114300232A

CN114300232A - Inductor, circuit board integrated inductor, power management chip and electronic equipment

Info

Publication number: CN114300232A
Application number: CN202111662549.3A
Authority: CN
Inventors: 蓝昊; 陈奕君
Original assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Current assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Priority date: 2021-12-30
Filing date: 2021-12-30
Publication date: 2022-04-08

Abstract

The application provides an inductor, a circuit board integrated inductor, a power management chip and electronic equipment. The inductor includes: a coil layer having a coil; the magnetic film layer is arranged on one side of the coil layer and comprises a magnetic alloy, and the equivalent conductivity sigma of the magnetic film layer is within the range of 4KS/m and 600 KS/m; the range of the relative magnetic permeability mu r of the magnetic film layer is more than or equal to 500 and less than or equal to 6000. The inductor of the embodiment of the application has thicker skin depth and higher inductance.

Description

Inductor, circuit board integrated inductor, power management chip and electronic equipment

Technical Field

The application relates to the field of electronics, and in particular relates to an inductor, a circuit board integrated inductor, a power management chip and electronic equipment.

Background

With the trend of miniaturization and high density of electronic hardware, the surface area of the circuit board is reduced sharply, but the number of electronic components required to be mounted on the board is increased or decreased. An inductor is an indispensable component of an electronic device, however, the skin depth of a magnetic film layer having a high relative permeability currently applied to the inductor is generally small, and thus it is difficult to effectively disperse magnetic flux by increasing the thickness of the magnetic film layer.

Disclosure of Invention

In view of the above problem, an embodiment of a first aspect of the present application provides an inductor, which includes:

a coil layer having a coil; and

the magnetic film layer is arranged on one side of the coil layer and comprises a magnetic alloy, and the equivalent conductivity sigma of the magnetic film layer is within the range of 4KS/m and less than or equal to sigma and less than or equal to 600 KS/m; the range of the relative magnetic permeability mu r of the magnetic film layer is more than or equal to 500 and less than or equal to 6000.

The embodiment of the second aspect of the present application provides a power management chip, where the power management chip includes a power circuit and an inductor in the embodiment of the present application, and the inductor is electrically connected to the power circuit.

An embodiment of a third aspect of the present application provides a circuit board integrated inductor, which includes:

the circuit board comprises a substrate and a coil, and the coil is embedded in the substrate; and

the magnetic film layer is arranged on one side of the circuit board and at least partially overlapped with the coil, the magnetic film layer comprises magnetic alloy, and the equivalent conductivity sigma of the magnetic film layer is in a range of 4KS/m and less than or equal to sigma and less than or equal to 600 KS/m; the range of the relative magnetic permeability mu r of the magnetic film layer is more than or equal to 500 and less than or equal to 6000.

An embodiment of a fourth aspect of the present application provides an electronic device, where the electronic device includes the inductor in the embodiment of the present application, or includes a power management chip in the embodiment of the present application, or includes the circuit board integrated inductor in the embodiment of the present application.

The inductor comprises a coil layer and a magnetic film layer; the coil layer has a coil; the magnetic film layer is arranged on one side of the coil layer, and the equivalent conductivity sigma of the magnetic film layer is within the range of 4KS/m and less than or equal to sigma and less than or equal to 600 KS/m; the relative magnetic permeability mu r of the magnetic film layer 30 is within the range of 3000 mu r to 9000. Therefore, the magnetic film layer has lower equivalent conductivity while having higher relative permeability. Thereby make the magnetic film layer have thicker skin depth and higher inductance, can improve the saturation magnetic induction intensity of magnetic film layer through the thickness that increases the magnetic film layer, effectively disperse the magnetic flux to better be applicable to the scene of heavy current, in addition, can also improve the inductance of inductance through the thickness that increases the magnetic film layer, improve the utilization ratio of magnetic film layer.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of an inductor according to an embodiment of the present application.

Fig. 2 is a schematic cross-sectional view of an inductor along a direction a-a in fig. 1 according to an embodiment of the present application.

Fig. 3 is a schematic structural diagram of a magnetic film layer according to an embodiment of the present application.

FIG. 4 is a schematic structural diagram of a magnetic film layer according to yet another embodiment of the present application.

Fig. 5 is a schematic cross-sectional view of an inductor along a-a direction in fig. 1 according to another embodiment of the present application.

Fig. 6 is a schematic cross-sectional view of an inductor according to another embodiment of the present application along a-a direction in fig. 1.

Fig. 7 is a circuit block diagram of a power management chip according to an embodiment of the present application.

Fig. 8 is a schematic perspective structural diagram of a circuit board integrated inductor according to an embodiment of the present application.

Fig. 9 is a schematic cross-sectional view of the circuit board integrated inductor along the direction B-B in fig. 8 according to an embodiment of the present application.

Fig. 10 is a schematic structural diagram of a circuit board according to an embodiment of the present application.

Fig. 11 is a schematic structural diagram of a circuit board according to another embodiment of the present application.

Fig. 12 is a schematic cross-sectional view of the circuit board of the embodiment of the present application along the direction B-B in fig. 8.

Fig. 13 is a schematic cross-sectional view of a circuit board according to another embodiment of the present application along the direction B-B in fig. 8.

Fig. 14 is a schematic structural diagram of a circuit board according to another embodiment of the present application.

Fig. 15 is a schematic structural diagram of a coil according to yet another embodiment of the present application.

Fig. 16 is a schematic structural diagram of a circuit board according to another embodiment of the present application.

Fig. 17 is a circuit block diagram of a circuit board integrated inductor according to an embodiment of the present application.

Fig. 18 is a schematic cross-sectional view of a circuit board integrated inductor along the direction B-B in fig. 8 according to another embodiment of the present application.

Fig. 19 is a schematic cross-sectional view of a circuit board integrated inductor along the direction B-B in fig. 8 according to another embodiment of the present application.

Fig. 20 is a schematic structural diagram of an electronic device according to an embodiment of the present application.

Fig. 21 is a schematic diagram of a partially exploded structure of an electronic device according to an embodiment of the present application.

Description of reference numerals:

100-inductor, 10-coil layer, 11-coil, 13-substrate, 20-magnetic glue layer, 30-magnetic film layer, 31-magnetic film layer, 33-metal oxide layer, 35-insulating layer, 50-insulating layer, 200-power management chip, 210-power circuit, 300-circuit board integrated inductor, 310-circuit board, 311-base plate, 311 a-dielectric layer, 313-conducting layer, 313 a-conducting wire, 10 b-functional circuit, 11 b-processor, 13 b-memory, 400-electronic device, 410-display component, 430-shell, 440-circuit board component.

Detailed Description

In order to make the technical solutions better understood by those skilled in the art, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The terms "first," "second," and the like in the description and claims of the present application and in the above-described drawings are used for distinguishing between different objects and not for describing a particular order. Furthermore, the terms "include" and "have," as well as any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those steps or elements listed, but may alternatively include other steps or elements not listed, or inherent to such process, method, article, or apparatus.

The technical solutions in the embodiments of the present application will be described below with reference to the accompanying drawings. It should be noted that, for convenience of description, like reference numerals denote like parts in the embodiments of the present application, and a detailed description of the like parts is omitted in different embodiments for the sake of brevity.

Inductance generally refers to an inductor. An Inductor (Inductor) is a component that can convert electrical energy into magnetic energy for storage. The inductor consists of a coil and a magnetic part, when alternating current passes through the coil, alternating magnetic flux is generated inside and around the coil, and the inductor has the functions of storing and releasing energy.

In order to enable the inductor to have larger inductance, a magnetic material with high relative permeability can be adopted, magnetic induction lines are distributed in a magnetic film in a concentrated mode, the maximum magnetic induction intensity of the inductor easily reaches saturated magnetic induction intensity, the maximum magnetic induction intensity exceeds the saturated magnetic induction intensity which can be endured by the magnetic material, the practicability is lost, the magnetic flux can be effectively dispersed through the increased thickness of the magnetic film layer within a certain thickness range, and the maximum magnetic induction intensity of the inductor is reduced. However, the current magnetic material with high relative permeability generally has higher electrical conductivity, so the skin depth of the prepared magnetic film layer is very small, and when the thickness of the magnetic film layer reaches the skin depth, the magnetic flux is difficult to be effectively dispersed even by increasing the thickness, which greatly limits the application of the magnetic material with high relative permeability in the inductor.

Referring to fig. 1 and fig. 2, an inductor 100 according to an embodiment of the present disclosure includes a coil layer 10 and a magnetic film layer 30; the coil layer 10 has a coil 11; the magnetic film layer 30 is arranged on one side of the coil layer 10, the magnetic film layer 30 comprises a magnetic alloy, and the equivalent electrical conductivity sigma of the magnetic film layer 30 is within the range of 4KS/m and less than or equal to sigma and less than or equal to 600 KS/m; the relative magnetic permeability mu r of the magnetic film layer 30 is more than or equal to 500 and less than or equal to 6000.

The number of coils 11 in the coil layer 10 may be at least one, such as 1, two, three, four, etc. "at least one" means greater than or equal to one.

It is understood that each coil 11 may be, but is not limited to, a portion of one turn coil 11 (e.g., half turn coil 11, 0.3 turn coil 11, etc.), one turn coil 11, two turn coil 11, three turn coil 11, four turn coil 11, five turn coil 11, etc. The more turns of the coil 11, the larger the amount of the inductor 100 is under otherwise constant conditions. Therefore, the number of turns of the coil 11 may be designed according to the application scenario, the required amount of the inductor 100, and the like, and the present application is not limited in particular.

Alternatively, the magnetic film layer 30 may be disposed on one side of the coil layer 10, or may be disposed on two opposite sides of the coil layer 10.

The equivalent conductivity sigma of the magnetic film layer 30 is within the range of 4 KS/m-600 KS/m; specifically, the magnetic film layer 30 can have a conductivity σ of, but is not limited to, 4KS/m, 6KS/m, 10KS/m, 40KS/m, 60KS/m, 80KS/m, 100KS/m, 200KS/m, 300KS/m, 400KS/m, 500KS/m, 600KS/m, and the like. Under the condition that the relative permeability of the magnetic film layer 30 is not changed, the smaller the equivalent conductivity σ of the magnetic film layer 30 is, the larger the skin depth of the obtained magnetic film layer 30 is, and the saturation magnetic induction intensity of the magnetic film layer 30 can be better improved by increasing the thickness of the magnetic film layer 30, so that the inductor 100 can be better applied to a scene with larger current. "equivalent conductivity" refers to the conductivity that the magnetic film layer 30 is equivalent to a homogeneous material.

The range of the relative magnetic permeability mu r of the magnetic film layer 30 is more than or equal to 500 and less than or equal to 6000; specifically, the relative permeability μ r of the magnetic film layer 30 may be, but is not limited to, 500, 800, 1000, 1500, 2000, 2500, 3000, 3500, 4000, 4500, 5000, 5500, 6000, etc. The smaller the relative permeability of the magnetic film layer 30 is, the larger the skin depth of the magnetic film layer 30 is, but the too low relative permeability greatly reduces the inductance of the inductor 100, and therefore, the relative permeability of the magnetic film layer 30 is not preferably too low.

The inductor 100 of the embodiment of the present application includes a coil layer 10 and a magnetic film layer 30; the coil layer 10 has a coil 11; the magnetic film layer 30 is arranged on one side of the coil layer 10, and the equivalent conductivity sigma of the magnetic film layer 30 is within the range of 4KS/m and less than or equal to sigma and less than or equal to 600 KS/m; the relative permeability mu r of the magnetic film layer 30 is within the range of 3000 mu r 9000. Therefore, the magnetic film layer 30 has a higher relative permeability and a lower equivalent conductivity, so that the magnetic film layer 30 has a thicker skin depth and a higher sensitivity. Therefore, the saturation magnetic induction intensity of the magnetic film layer 30 can be improved by increasing the thickness of the magnetic film layer 30, and the magnetic flux can be effectively dispersed, so that the inductor is better suitable for a large-current scene, and in addition, the inductance of the inductor 100 can be improved by increasing the thickness of the magnetic film layer 30, and the utilization rate of the magnetic film layer 30 can be improved.

Referring again to fig. 2, in some embodiments, the coil layer 10 further includes a substrate 13, and the substrate 13 is used for carrying the coil 11. In some embodiments, the coil 11 may be embedded in the substrate 13. Specifically, the coil 11 may be partially located inside the substrate 13 and partially located on the surface of the substrate 13; or may be entirely within the substrate 13. In other embodiments, the coil 11 is disposed on at least one surface of the substrate 13.

Alternatively, the substrate 13 may be, but is not limited to, a polyimide layer, a glass fiber/epoxy composite plate, polyethylene, polytetrafluoroethylene, etc., and the present application is not limited thereto. Optionally, the thickness of the substrate 13 is 10 μm to 50 μm; specifically, it may be, but not limited to, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, or the like. When the thickness of the substrate 13 is too small, for example, less than 10 μm, the mechanical properties of the substrate 13 are limited, and it is difficult to effectively support the coil 11; since the permeability of the substrate 13 is low, if the thickness of the substrate 13 is too large, for example, greater than 50 μm, the length of the magnetic path is increased, so that the magnetic resistance is increased, which is detrimental to the performance of the inductor 100.

In some embodiments, the ratio L/Bm of the inductance L of the inductor 100 to the maximum magnetic induction Bm of the magnetic film layer 30 is in a range of 3.8nH/T < L/Bm < 18.1 nH/T. Specifically, L/Bm can be, but is not limited to, 3.8nH/T, 4.5nH/T, 6nH/T, 8nH/T, 10nH/T, 12nH/T, 14nH/T, 18.1nH/T, and the like. The larger the value of L/Bm, the larger the inductance 100 can be made by using a smaller maximum magnetic induction, so that the inductor 100 with a larger inductance can be made by using a magnetic material with a smaller saturation magnetic induction. "Bm" refers to the magnetic induction at the position where the magnetic induction is the greatest in the magnetic film layer 30.

Alternatively, the magnetic film layer 30 has a skin depth δ in the range of 8.40 μm δ 103 μm at a frequency of 1 MHz. Specifically, the skin depth δ may be, but is not limited to, 8.4 μm, 10 μm, 12.5 μm, 15 μm, 17.5 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 96 μm, 103 μm, and the like. The larger the skin depth is, the better the saturation magnetic induction intensity of the magnetic film layer 30 can be improved by increasing the thickness of the magnetic film layer 30, so that the magnetic flux can be better dispersed, the inductor 100 can be better suitable for a large-current scene, and meanwhile, the inductance of the inductor 100 can be better improved by increasing the thickness of the magnetic film layer 30, so that the magnetic film layer 30 can be thicker. The magnetic film layer 30 of the present application has a higher skin depth to the maximum magnetic induction (Bm) in the magnetic film layer 30 is reduced by the better dispersed magnetic flux, and simultaneously has a higher inductance, so that the inductance having a larger inductance can be obtained by using a material having a smaller saturation magnetic induction.

In some embodiments, the magnetic alloy is a modified magnetic alloy. The modified magnetic alloy comprises at least one of chromium-doped iron-nickel alloy, chromium-doped iron-cobalt alloy, chromium-doped iron-silicon-aluminum alloy and the like. The magnetic alloy has higher relative permeability, so that the manufactured inductor 100 has larger inductance, and meanwhile, the relative permeability of the magnetic alloy can not be reduced too much by chromium doping, so that the equivalent conductivity of the magnetic alloy is greatly reduced, and the skin depth of the magnetic film layer 30 is increased. Therefore, the thickness of the magnetic film layer 30 can be increased, so that the magnetic film layer 30 has higher saturation magnetic induction intensity, magnetic flux can be better dispersed, the maximum magnetic induction intensity when the magnetic film layer 30 is applied is reduced, and the inductor 100 can be better applied to a scene with larger current.

Referring to fig. 3, in some embodiments, the magnetic film layer 30 includes a magnetic film sublayer 31 and a metal oxide layer 33 alternately stacked in sequence, wherein the magnetic film sublayer 31 may be a modified magnetic alloy layer, and the metal oxide layer 33 includes an oxide of at least one metal in the modified magnetic alloy. By alternately stacking the modified magnetic alloy and the metal oxide layer 33, the equivalent conductivity of the magnetic film layer 30 can be sufficiently reduced, but the relative permeability of the magnetic film layer 30 is not reduced too much.

Alternatively, the magnetic film layer 30 of the present embodiment may be prepared by:

1) depositing a metal layer on the insulating base material as a seed layer by methods such as chemical plating and the like to ensure that the insulating base material has conductivity;

2) placing the insulating substrate having the seed layer in a plating solution containing chromium ions, particles of a metal included in the magnetic alloy, such as iron ions, nickel ions, etc., to perform plating, to form a chromium-doped magnetic alloy layer on the surface of the seed layer;

3) standing for a period of time to allow a metal oxide layer 33 to be formed on the surface of the chromium-doped magnetic alloy layer; and

4) and circulating the steps 2) and 3) to form a magnetic film layer 30 structure in which the magnetic film sublayers 31 and the metal oxide layers 33 are sequentially and alternately laminated.

Referring to fig. 4, in other embodiments, the magnetic film layer 30 includes an insulating sub-layer 35 and a magnetic film sub-layer 31 alternately stacked in sequence, wherein the insulating sub-layer 35 includes at least one of silicon dioxide and aluminum oxide, and the magnetic film sub-layer 31 includes a magnetic alloy. By alternately laminating the inorganic insulating layers and the magnetic metal layers, the equivalent conductivity of the magnetic film layer 30 can be sufficiently reduced, but the relative permeability of the magnetic film layer 30 is not reduced too much.

Alternatively, the insulating sub-layer 35 may be formed by Atomic Layer Deposition (ALD), sputtering, evaporation, or the likePlating a layer of nano-scale SiO₂The film layer or the alumina film layer and the like play an insulating role. The magnetic film sublayer 31 may be prepared by electroplating.

Optionally, the thickness h2 of the magnetic film layer 30 is in the range of 8 μm & lt h2 & lt 110 μm; specifically, it may be, but not limited to, 8 μm, 10 μm, 12.5 μm, 15 μm, 17.5 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, or the like. The larger the thickness of the magnetic film layer 30 is, the larger the inductance of the obtained inductor 100 is, and the larger the value of L/Bm is, and in application, the inductor 100 can have a larger inductance only by requiring a smaller maximum magnetic induction intensity, so that the inductor 100 having a larger inductance can be prepared by using a magnetic material having a smaller saturation magnetic induction intensity.

Referring to fig. 5, in some embodiments, the inductor 100 further includes a magnetic glue layer 20, the magnetic glue layer 20 is disposed between the coil layer 10 and the magnetic film layer 30; the magnetic permeability of the magnetic film layer 30 is greater than that of the magnetic glue layer 20. The magnetic glue layer 20 and the magnetic film layer 30 are combined together to be used as the magnetic layer in the inductor 100, and compared with the situation that only the magnetic glue layer 20 or the magnetic film layer 30 is provided, the obtained inductance is greatly increased and far exceeds the accumulated value of the inductance of the single magnetic glue layer 20 and the inductance of the single magnetic film layer 30, the ultrathin high inductance can be better realized, and the ultrathin high inductance is beneficial to the ultrathin and miniaturization of the inductor 100.

In one embodiment, the magnetic film layer 30 is formed on the surface of the magnetic glue layer 20 away from the coil layer 10. The magnetic glue layer 20 refers to a film layer including magnetic materials discontinuously distributed therein with breaks between the magnetic materials.

In some embodiments, the magnetic layer 20 includes a resin and magnetic particles dispersed in the resin. The magnetic paste layer 20 may be formed by dispersing magnetic particles in a liquid resin to form a magnetic paste, coating or printing the magnetic paste on one side of the coil layer 10, and curing (e.g., uv light-curing).

Optionally, in the magnetic glue layer 20, the weight fraction of the magnetic particles ranges from 85% to 95%. Specifically, the weight fraction of the magnetic particles may be, but is not limited to, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, etc. When the weight fraction of the magnetic particles in the magnetic layer 20 is less than 85%, the magnetic permeability of the formed magnetic layer 20 is too low, which is not favorable for improving the inductance of the inductor 100, and when the weight fraction of the magnetic particles in the magnetic layer 20 is more than 95%, the content of the resin is too low, which may cause the magnetic particles to gather together, which is equivalent to the effect of large particles, so that the iron loss of the inductor 100 is increased.

Alternatively, the D90 particle size of the magnetic particles ranges from: d90 is more than or equal to 1 mu m and less than or equal to 10 mu m. Specifically, the D90 particle size of the magnetic particles may be, but is not limited to, 1 μm, 2 μm, 4 μm, 6 μm, 8 μm, 10 μm, and the like. Furthermore, the D90 particle size of the magnetic particles may also be any range of values between 1 μm to 10 μm, such as 1 μm to 5 μm, or 4 μm to 8 μm; or 5 μm to 10 μm. When the magnetic particles are small, the eddy current is limited to a small range; as the magnetic particles grow larger, the area through which eddy currents can flow becomes larger, thereby increasing eddy current loss. However, when the average particle diameter of the magnetic particles is less than 1 μm, not only the cost of the magnetic particles is increased, but also the magnetic permeability of the magnetic paste layer 20 is decreased. When the average particle diameter of the magnetic particles is larger than 10 μm, the eddy current loss increases and the performance of the inductor 100 is also not facilitated. D90 refers to the size value measured for the particle size of 90% of the particles. For example, a D90 particle size range of 1 μm. ltoreq. D90. ltoreq.10 μm for the magnetic particles means that 90% of the magnetic particles have a particle size of 1 μm to 10 μm.

Optionally, the magnetic particles are soft magnetic particles. Soft magnetism has high magnetic permeability, low remanence, low coercivity, low magnetic resistance, low hysteresis loss, and is easily magnetized. Optionally, the magnetic particles comprise at least one of ferrite particles, magnetic metal particles, magnetic alloy particles. Ferrite particles, especially NiZn ferrite, have lower electrical conductivity and thus lower loss, and magnetic alloy particles have higher magnetic saturation induction. Therefore, when the magnetic adhesive layer 20 is required to have better electrical insulation and lower loss, ferrite particles with higher proportion can be selected as the magnetic particles; when the magnetic adhesive layer 20 is required to have higher magnetic saturation induction, magnetic alloy particles with higher proportion can be selected as the magnetic particles. Optionally, the ferrite particles comprise at least one of MnZn ferrite, NiZn ferrite, and the like. Optionally, the magnetic metal particles comprise at least one of iron, cobalt, nickel, and the like. Alternatively, the magnetic alloy particles include at least one of an iron-based crystalline alloy, an iron-based amorphous alloy, a cobalt-based amorphous alloy, and the like. The iron-based crystalline alloy includes at least one of a FeNi alloy, a FeCo alloy, a FeAl alloy, a FeSiAl alloy, a FeNiMo alloy, a FeC alloy, and the like. The iron-based amorphous alloy includes at least one of FeSiB alloy, FeB alloy, FeNiPB alloy, FeNiMoB alloy, and the like. The cobalt-based amorphous alloy includes at least one of CoFeSiB alloy, CoFeCrSiB alloy, CoNiFeSiB alloy, and the like.

The cobalt-based amorphous alloy has a higher magnetic permeability than the iron-based crystalline alloy and the iron-based amorphous alloy, and thus, when the magnetic gel layer 20 requires a higher magnetic permeability, at least one of the cobalt-based amorphous alloys may be used as the magnetic particles. Compared with cobalt-based amorphous alloys, iron-based crystalline alloys and iron-based amorphous alloys have higher saturation magnetic characteristics, and when the magnetic colloid layer 20 requires higher saturation magnetic characteristics, the magnetic particles can be at least one of iron-based crystalline alloys and iron-based amorphous alloys. Compared with the iron-based crystalline alloy, the iron-based amorphous alloy and the cobalt-based amorphous alloy have lower coercive force, and when the magnetic colloid layer 20 requires lower coercive force, the iron-based amorphous alloy and the cobalt-based amorphous alloy can be used as the magnetic particles.

Optionally, when the magnetic particles are magnetic alloy particles, the surface of the magnetic alloy particles has a passivation layer, which is an insulating layer, in other words, the passivation layer is insulating. In some embodiments, a layer of organic resin may be coated on the surface of the magnetic alloy particles to insulate the magnetic alloy particles. In other embodiments, the magnetic alloy particles may be passivated with phosphoric acid to form a non-conductive passivation layer on the surface of the magnetic alloy particles.

Alternatively, the thickness h1 of the magnetic glue layer 20 is in the range of 50 μm & lt h1 & lt 500 μm in the lamination direction of the magnetic glue layer 20 and the magnetic film layer 30, and specifically, the thickness h1 of the magnetic glue layer 20 can be, but not limited to, 5 μm, 10 μm, 30 μm, 50 μm, 80 μm, 100 μm, 120 μm, 140 μm, 160 μm, 180 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, 500 μm, and the like. When the thickness h1 of the magnetic paste layer 20 is less than 50 μm, it may be difficult for the magnetic paste layer 20 to completely cover the coil 11 of the coil layer 10, resulting in a possibility that the surface of the magnetic paste layer 20 may have steps, which is disadvantageous for the deposition of the magnetic film layer 30. When the thickness h1 of the magnetic layer 20 is larger than 500 μm, the inductor 100 device is larger.

Alternatively, the resin includes at least one of epoxy, polyurethane, acrylate, and the like.

Referring to fig. 6, in some embodiments, the inductor 100 further includes an insulating layer 50, where the insulating layer 50 is disposed between the coil layer 10 and the magnetic adhesive layer 20, and is used to insulate the coil 11 from the magnetic adhesive layer 20, so as to prevent the magnetic particles of the magnetic adhesive layer 20 from being unevenly dispersed, which may cause a short circuit between the coil layer 10 and a local magnetic particle accumulation.

Optionally, the insulating layer 50 covers at least the coil, and furthermore, the insulating layer 50 may also cover the entire substrate 13.

Alternatively, the insulating layer 50 includes at least one of a ceramic insulating layer 50, an organic insulating layer 50, and the like; the ceramic insulating layer 50 includes at least one of alumina, silica, and the like; the organic insulating layer 50 includes at least one of polypropylene, polytetrafluoroethylene, polyimide, and the like. The ceramic insulating layer 50 has better insulating properties and mechanical strength compared to the organic insulating layer 50, but the organic insulating layer 50 has lower manufacturing costs. The material of the insulating sub-layer 35 can be selected according to the requirements of practical application. Alternatively, the insulating layer 50 may be formed by physical vapor deposition, atomic layer deposition, or other coating process.

Referring to fig. 7, an embodiment of the present application further provides a power management chip 200, where the power management chip 200 includes a power circuit 210 and the inductor 100 according to the above embodiments of the present application, and the inductor 100 is electrically connected to the power circuit 210.

The power management chip 200 may assume responsibility for power conversion, distribution, detection and other power management in the electronic device 400 system. The power management chip 200 is mainly responsible for identifying the amplitude of the CPU power supply, generating a corresponding short moment wave, and pushing the subsequent circuit to output power. In an embodiment, the inductor 100 may be applied to a transformation circuit of the power management chip 200, such as a voltage boosting circuit, a voltage dropping circuit, and the like. Alternatively, the power supply circuit 210 may be, but is not limited to, a voltage boosting circuit, a voltage dropping circuit, or the like.

For a detailed description of the inductor 100, reference is made to the description of the corresponding parts of the above embodiments, which are not repeated herein.

The inductance device occupies a large area on the circuit board, for example, in the power module, the inductance device occupies more than 40% of the area of the surface of the power board, which is not only unfavorable for the miniaturization and high density of the product; and most of inductance devices need to be separately mounted, so that the packaging efficiency is reduced. Thus, the embodiment of the present application further provides a circuit board integrated inductor 300.

Referring to fig. 8 and 9, the circuit board integrated inductor 300 includes a circuit board 310 and a magnetic film layer 30; the circuit board 310 includes a substrate 311 and a coil 11, wherein the coil 11 is embedded in the substrate 311; the magnetic film layer 30 is arranged on one side of the circuit board 310, the magnetic film layer 30 is at least partially overlapped with the coil 11, the magnetic film layer 30 comprises magnetic alloy, and the equivalent conductivity sigma of the magnetic film layer 30 is in a range of 4 KS/m-600 KS/m; the relative magnetic permeability mu r of the magnetic film layer 30 is more than or equal to 500 mu r and less than or equal to 6000 mu r.

The circuit board 310 may be a flexible circuit board (FPC) or a Printed Circuit Board (PCB), and the present application is not limited thereto. The number of the coils 11 on the circuit board 310 may be one, or may be multiple, for example, but not limited to, 1, 2, 3, etc., and the specific number of the coils 11 may be set according to the actual application requirement, which is not specifically limited in this application. The plurality means two or more or two or more.

The coil 11 is embedded in the substrate 311, and the coil 11 can be at least partially wrapped by the substrate 311; the coil 11 and the substrate 311 may also be integrated into a whole structure, so as to be integrated into the circuit board 310, the coil 11 may be directly composed of a conducting wire in the circuit board 310, and the coil 11 is formed together with the circuit board 310 in the preparation process; the coil 11 may be disposed through the substrate 311, in other words, the coil 11 partially penetrates the substrate 311 and partially exposes the substrate 311.

The coil 11 may be embedded in the substrate 311 at a corresponding position where inductance is required to be provided. The coil 11 is a small part of the circuit board 310, and therefore, the magnetic film layer 30 may be disposed only on the portion of the substrate 311 on which the coil 11 is disposed. Further, the magnetic film layer 30 may cover a surface of the substrate 311 except for the coil 11. In order to achieve cost savings and better performance of the circuit board integrated inductor 300, the magnetic film layer 30 may cover the entire coil 11.

The magnetic film layer 30 at least partially overlaps the coil 11, which means that the magnetic film layer 30 at least partially overlaps the orthographic projection of the coil 11 on the surface of the circuit board 310. The magnetic film layer 30 is at least partially overlapped with the coil 11, and the magnetic film layer 30 can be partially overlapped with the coil 11; it is also possible for the magnetic film layer 30 to cover the entire surface of the coil 11; the magnetic film layer 30 may also cover the coil 11, be located within the coil 11, etc.

The circuit board integrated inductor 300 of the embodiment integrates the inductor on the circuit board 310, and when the inductor is applied to the electronic device 400, the electronic device 400 can be more miniaturized and ultrathin, and the inductor and the circuit board 310 are manufactured together without independent mounting, so that the packaging efficiency is improved. In addition, the inductor is integrated in the circuit board 310, and the position of the circuit board 310 corresponding to the inductor can be saved for mounting other components, thereby saving the area of the circuit board 310 and enhancing the wiring and piece distributing capacity of the circuit board 310. Further, the equivalent conductivity σ of the magnetic film layer 30 of the embodiment of the present application ranges from 4KS/m ≦ σ ≦ 600 KS/m; the relative magnetic permeability mu r of the magnetic film layer 30 is more than or equal to 500 mu r and less than or equal to 6000 mu r. Therefore, the magnetic film layer 30 has a higher relative permeability and a lower equivalent conductivity, so that the magnetic film layer 30 has a thicker skin depth and a higher sensitivity. Therefore, the saturation magnetic induction intensity of the magnetic film layer 30 can be improved by increasing the thickness of the magnetic film layer 30, so that the magnetic film layer is better suitable for a large-current scene, and in addition, the inductance can be improved by increasing the thickness of the magnetic film layer 30, so that the utilization rate of the magnetic film layer 30 is improved.

Referring to fig. 10 to 13, optionally, the circuit board 310 further includes at least one dielectric layer 311a and at least one conductive layer 313; at least one dielectric layer 311a constitutes the substrate 311, the dielectric layers 311a and the conductive layers 313 are sequentially and alternately stacked, and the conductive layers 313 include conductive wires 313 a; when the conductive layer 313 is one layer, the conductive line 313a of the single conductive layer 313 forms the coil 11; when the conductive layers 313 are formed in a plurality of layers, the conductive lines 313a of any adjacent two conductive layers 313 are electrically connected to form the coil 11. The coil 11 is formed by adopting the original conductive layer 313 of the circuit board 310, so that the coil 11 of the inductor is integrated on the circuit board 310, the preparation process is simpler, and the obtained circuit board integrated inductor 300 is thinner and more miniaturized.

As shown in fig. 11, in some embodiments, the circuit board 310 includes a dielectric layer 311a and a conductive layer 313 stacked together, the conductive layer 313 includes a conductive wire 313a, such as one, two, three, four conductive wires 313a, etc., and the conductive wires 313a form the coil 11 (or one conductive wire 313a forms one coil 11). As shown in fig. 12, in another embodiment, the circuit board 310 includes a dielectric layer 311a and two conductive layers 313 stacked one on another, the two conductive layers 313 are respectively disposed on two opposite surfaces of the dielectric layer 311a, the two conductive layers 313 each include a conductive wire 313a, and the conductive wires 313a of the two conductive layers 313 are electrically connected to form the coil 11. As shown in fig. 14, in other embodiments, the circuit board 310 includes a dielectric layer 311a and two conductive layers 313 stacked together, the two conductive layers 313 are respectively disposed on two opposite surfaces of the dielectric layer 311a, each of the two conductive layers 313 includes two conductive wires 313a, one of the conductive wires 313a of the two conductive layers 313 is electrically connected to form one coil 11, and the other conductive wire 313a is electrically connected to form another coil 11, in other words, two coils 11 are formed. As shown in fig. 13, in other embodiments, the circuit board 310 includes two dielectric layers 311a and three conductive layers 313 stacked in layers, the dielectric layers 311a and the conductive layers 313 are alternately stacked in sequence, each conductive layer 313 includes a conductive line 313a, and the conductive lines 313a of any two adjacent conductive layers 313 are electrically connected to form the coil 11. The number of the dielectric layers 311a and the conductive layers 313 in the circuit board 310 is not particularly limited, as long as a structure in which the dielectric layers 311a and the conductive layers 313 are alternately stacked in sequence can be formed, and the number can be specifically designed according to actual requirements.

Alternatively, the dielectric layer 311a may include, but is not limited to, at least one of Polyimide (PI), glass fiber/epoxy composite board (Prepreg), and the like. The conductive line 313a may include, but is not limited to, at least one of copper, silver conductive metal, or alloy. When the flexible circuit board 310(FPC) needs to be prepared, polyimide may be used as the dielectric layer 311a, and when the printed circuit board 310 (PCB) needs to be prepared, a glass fiber/epoxy composite board may be used as the dielectric layer 311 a. In one embodiment, the dielectric layer 311a is polyimide and the conductive line 313a is copper line.

Alternatively, the thickness of each dielectric layer 311a is 10 μm to 50 μm in the lamination direction of the dielectric layer 311a and the conductive layer 313; specifically, it may be, but not limited to, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, or the like. When the thickness of the dielectric layer 311a is too small, for example, less than 10 μm, the mechanical properties of the dielectric layer 311a are limited, and it is difficult to effectively support the conductive layer 313; since the permeability of the dielectric layer 311a is very low, if the thickness of the dielectric layer 311a is too large, for example, greater than 50 μm, the length of the magnetic path is increased, so that the magnetic resistance is increased, which is not favorable for the performance of the inductor 100.

In the embodiments of the present application, when referring to the numerical ranges a to b, if not specifically indicated, the end value a is included, and the end value b is included. For example, the thickness of the conductive line 313a is 50 μm to 150 μm, and the thickness of the conductive line 313a may be any value between 50 μm to 150 μm, including a terminal 50 μm and a terminal 150 μm.

Referring to fig. 15, optionally, the thickness d1 of the conductive line 313a along the stacking direction of the dielectric layer 311a and the conductive layer 313 ranges from 50 μm to 150 μm, and specifically may be, but is not limited to, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, and the like.

Alternatively, the width d2 of the conductive line 313a (i.e., the width parallel to the extending direction of the dielectric layer 311 a) ranges from 100 μm to 300 μm; specifically, it may be, but not limited to, 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 180 μm, 200 μm, 220 μm, 240 μm, 280 μm, 300 μm, or the like.

Alternatively, in the same turn of coil 11, the distance d3 between two portions of conducting wires 313a oppositely arranged is in the range of 100 μm to 200 μm; specifically, it may be, but not limited to, 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 180 μm, 200 μm. In one embodiment, the thickness of the conductive lines 313a is 100 μm, the width of the conductive lines 313a is 200 μm, and the pitch of the conductive lines 313a is 150 μm.

Referring to fig. 16 and 17, in some embodiments, the circuit board 310 further includes a functional circuit 10b, and the functional circuit 10b is carried on the substrate 311 and electrically connected to the coil 11.

Referring to fig. 17, the functional circuit 10b includes a processor 11b and a memory 13b, the processor 11b and the memory 13b are disposed on the surface of the substrate 311, and the processor 11b is electrically connected to the memory 13b and the coil 11. The processor 11b is used for controlling the magnitude, direction and the like of the current of the coil 11. The memory 13b is used for storing program codes required for the processor 11b to operate.

Alternatively, processor 11b includes one or more general-purpose processors, wherein a general-purpose processor may be any type of device capable of Processing electronic instructions, including a Central Processing Unit (CPU), a microprocessor, a microcontroller, a main processor, a controller, an ASIC, and so forth. The processor 11b is configured to execute various types of digitally stored instructions, such as software or firmware programs stored in memory, which enable the computing device to provide a wide variety of services.

Alternatively, the Memory 13b may include a Volatile Memory (Volatile Memory), such as a Random Access Memory (RAM); the Memory 13b may also include a Non-Volatile Memory (NVM), such as a Read-Only Memory (ROM), a Flash Memory (FM), a Hard Disk (HDD), or a Solid-State Drive (SSD). The memory 13b may also comprise a combination of memories of the kind described above.

Optionally, when the number of turns of the coil 11 is 1 and the maximum current is 3A, the ratio of the inductance L of the circuit board integrated inductor 300 to the maximum magnetic induction Bm of the magnetic film layer 30 ranges from 3.8nH/T L/Bm 18.1 nH/T. For a detailed description, refer to the description of the corresponding parts of the above embodiments, which are not repeated herein.

Alternatively, the skin depth δ at a frequency of 1MHz is in the range 8.4 μm ≦ δ ≦ 103 μm. For a detailed description, refer to the description of the corresponding parts of the above embodiments, which are not repeated herein.

In some embodiments, the magnetic alloy is a modified magnetic alloy comprising at least one of a chromium-doped iron-nickel alloy, a chromium-doped iron-cobalt alloy, a chromium-doped iron-silicon-aluminum alloy. Optionally, the magnetic film layer 30 includes magnetic film sub-layers 31 and metal oxide layers 33 alternately stacked in sequence, the magnetic film sub-layers 31 are modified magnetic alloy layers, and the metal oxide layers 33 include oxides of at least one metal in the modified magnetic alloy.

In other embodiments, the magnetic film layer 30 includes insulating sub-layers 35 and magnetic film sub-layers 31 alternately stacked in sequence, the insulating sub-layers 35 include at least one of silicon dioxide and aluminum oxide, and the magnetic film sub-layers 31 include a magnetic alloy.

For other descriptions of the magnetic film 30, refer to the descriptions of the above corresponding parts, which are not repeated herein.

Referring to fig. 18, in some embodiments, the circuit board integrated inductor 300 further includes a magnetic glue layer 20, wherein the magnetic glue layer 20 is disposed between the coil 11 and the magnetic film layer 30; the magnetic permeability of the magnetic film layer 30 is greater than that of the magnetic glue layer 20. The magnetic adhesive layer 20 comprises resin and magnetic particles, and the magnetic particles are dispersed in the resin; in the magnetic glue layer 20, the weight fraction of the magnetic particles ranges from 85% to 95%; the D90 particle size of the magnetic particles is in the range of 1 μm to 10 μm of D90.

For a detailed description of other related technical features of the magnetic layer 20, please refer to the description of the corresponding parts of the above embodiments, which is not repeated herein.

Referring to fig. 19, in some embodiments, the circuit board integrated inductor 300 further includes an insulating layer 50, wherein the insulating layer 50 is disposed between the coil 11 and the magnetic layer 20 for insulating the coil 11 from the magnetic layer 20, so as to prevent the magnetic particles in the magnetic layer 20 from being unevenly dispersed, which may cause a short circuit between the local magnetic particle accumulation and the coil 11.

For a detailed description of the insulating layer 50, reference is made to the description of the corresponding parts of the above embodiments, which are not repeated herein.

The inductor of the present application is further described below with reference to specific examples. In each of the following examples and comparative examples, a simulation calculation was performed on an inductor 100 having a length of 1.6mm and a width of 0.8mm of the magnetic film layer 30, in which the maximum current passed through the inductor 100 was 3A, the applied frequency was 1MHz, and the number of turns of the coil 11 was 1 turn. The material of the magnetic film layer 30 is simulated by taking iron-nickel alloy or modified iron-nickel alloy as an example.

Examples 1 to 9 and comparative examples 1 to 3

The inductor 100 of the present embodiment and the comparative example includes a substrate 13, and a coil 11 is embedded on the substrate 13. The substrate 13 is a polyimide layer having a thickness of 12.5 μm. The coil 11 is partially embedded in the polyimide layer and partially exposed on two opposite surfaces of the polyimide layer, and the coil 11 is a copper coil 11. The line width of the copper coil 11 is 200 μm, the line thickness of the copper coil 11 is 100 μm, and the line pitch of the copper coil 11 is 150 μm. The inductor 100 of the present embodiment and the comparative example further includes a magnetic adhesive layer 20 and a magnetic film layer 30, the magnetic adhesive layer 20 and the magnetic film layer 30 are sequentially stacked on two opposite surfaces of the substrate 13 and at least cover the coil 11, the thickness of the magnetic adhesive layer 20 is 60 μm, the relative permeability of the magnetic adhesive layer 20 is 13, the relative permeability of the magnetic film layer 30 is 6000, and when performing the simulation calculation, it is assumed that the relative permeability of the magnetic film layer is isotropic. The relevant parameters of the magnetic film 30 are shown in tables 1, 2 and 3 below.

The values of the inductance 100 of the examples and comparative examples are shown in tables 1, 2 and 3 below, obtained by simulation calculations according to the standard GB/T8554-1998.

Table 1 simulation test data for inductors 100 of comparative examples 1 to 3

As can be seen from comparative examples 1 to 3 in table 1 above, when the electrical conductivity is 1700KS/m, the skin depth of the magnetic film layer 30 is about 5 μm, and the thicknesses of the magnetic film layers 30 of comparative examples 1 to 3 exceed the skin depth at this time, so that the maximum magnetic induction Bm is reduced little, the increase in inductance is small, and L/Bm is increased slightly after the thickness of the magnetic film layer 30 is increased from 10 μm to 30 μm and 50 μm, which means that it is difficult to effectively disperse magnetic flux by increasing the thickness of the magnetic film layer 30, thereby reducing the maximum magnetic induction Bm of the magnetic film layer 30 to increase the value of L/Bm.

Table 2 simulation test data for inductors 100 of examples 1-5

From the above table 2, it can be seen that when the conductivity is reduced to 40KS/m, the skin depth of the magnetic film layer 30 is about 131 μm, and from the simulation data of the embodiments 1 to 5, when the thickness of the magnetic film layer 30 is gradually increased from 10 μm to 50 μm, the increase of the inductance L is not very obvious, but the maximum magnetic induction intensity Bm of the magnetic film layer 30 is greatly increased, and L/Bm is also greatly increased, and when the thickness of the magnetic film layer 30 is increased to five times of the original thickness, L/Bm is also correspondingly increased to nearly four times of the original thickness. This shows that in the skin depth range, the increase of the thickness of the magnetic film layer 30 can effectively disperse the magnetic flux and reduce Bm, so that the inductor 100 can obtain a larger inductance L with a smaller Bm, and thus the inductor 100 with a large inductance can be manufactured by using a material with a smaller saturation magnetic induction.

Table 3 simulation test data for inductors 100 of examples 6-9

As can be seen from table 3 above, when the thickness of the magnetic film layer 30 is unchanged and the electrical conductivity is gradually increased, the skin depth of the magnetic film layer 30 is gradually decreased, the maximum magnetic induction Bm of the magnetic film layer 30 is gradually increased, the inductance L is basically unchanged, and L/Bm is gradually decreased. This shows that, when the thicknesses of the magnetic film layers 30 are the same, the maximum magnetic induction Bm of the magnetic film layer 30 can be greatly reduced by reducing the electrical conductivity of the magnetic film layer 30, thereby greatly improving L/Bm; when the conductivity is reduced from 600kS/m to 4kS/m, the L/Bm is increased from 3.8nH/T to 13.6nH/T, which is improved by nearly four times. This shows that the maximum magnetic induction Bm of the magnetic film 30 can be effectively reduced by reducing the electrical conductivity of the magnetic film 30, so that the inductor 100 can obtain a larger inductance L with a smaller Bm, and thus the inductor 100 with a large inductance can be manufactured by using a material with a smaller saturation magnetic induction.

Referring to fig. 20 and fig. 21, an electronic device 400 is further provided in the embodiment of the present application, where the electronic device 400 includes a display component 410, a housing 430, and a circuit board component 440. The display component 410 is for displaying; the housing 430 is disposed at one side of the display module 410; the circuit board assembly 440 is disposed between the display assembly 410 and the housing 430, and is electrically connected to the display assembly 410, and the circuit board assembly 440 is used for controlling the display assembly 410 to display. The circuit board assembly 440 includes the inductor 100 of the embodiment of the present application, or the power management chip 200, or the circuit board integrated inductor 300 of the embodiment of the present application.

For a detailed description of the inductor 100, the power management chip 200 and the circuit board integrated inductor 300, please refer to the description of the corresponding parts of the above embodiments, which is not repeated herein.

The electronic device 400 of the embodiment of the present application may be, but is not limited to, a portable electronic device such as a mobile phone, a tablet computer, a notebook computer, a desktop computer, a smart bracelet, a smart watch, an electronic reader, and a game console. The electronic device 400 in fig. 20 is illustrated as a mobile phone, and should not be construed as a limitation to the embodiment of the present application.

The case 430 of the present embodiment may have a 2D structure, a 2.5D structure, a 3D structure, and the like. The case 430 of the embodiment may be a rear cover (battery cover) of the electronic device 400, or a housing in which a middle frame and the rear cover are integrated.

Alternatively, the display assembly 410 may be, but is not limited to, one or more of a liquid crystal display assembly, a light emitting diode display assembly (LED display assembly), a Micro light emitting diode display assembly (Micro LED display assembly), a sub-millimeter light emitting diode display assembly (Mini LED display assembly), an organic light emitting diode display assembly (OLED display assembly), and the like.

It should be understood that the electronic device 400 in this embodiment is only one form of the electronic device 400 to which the inductor 100, the power management chip 200, and the circuit board integrated inductor 300 are applied, and should not be understood as a limitation on the electronic device 400 provided in this application, nor should be understood as a limitation on the inductor 100, the power management chip 200, and the circuit board integrated inductor 300 provided in each embodiment of this application.

Reference in the specification to "an embodiment" or "an implementation" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the specification. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein can be combined with other embodiments. Furthermore, it should be understood that the features, structures, or characteristics described in the embodiments of the present application may be combined arbitrarily without contradiction between them to form another embodiment without departing from the spirit and scope of the present application.

Finally, it should be noted that the above embodiments are only for illustrating the technical solutions of the present application and not for limiting, and although the present application is described in detail with reference to the above preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made to the technical solutions of the present application without departing from the spirit and scope of the technical solutions of the present application.

Claims

1. An inductor, comprising:

a coil layer having a coil; and

2. The inductor as claimed in claim 1, wherein the skin depth δ of the magnetic film layer is in the range of 8.4 μm δ 103 μm at a frequency of 1 MHz.

3. The inductor according to claim 1, wherein the magnetic alloy is a modified magnetic alloy comprising at least one of a chromium-doped iron-nickel alloy, a chromium-doped iron-cobalt alloy, a chromium-doped iron-silicon-aluminum alloy.

4. The inductor according to claim 3, wherein the magnetic film layer comprises a magnetic film sub-layer and a metal oxide layer alternately stacked in sequence, the magnetic film sub-layer is the modified magnetic alloy layer, and the metal oxide layer comprises an oxide of at least one metal in the modified magnetic alloy.

5. The inductor according to claim 1, wherein the magnetic film layer comprises an insulating sub-layer and a magnetic film sub-layer alternately stacked in sequence, the insulating sub-layer comprises at least one of silicon dioxide and aluminum oxide, and the magnetic film sub-layer comprises a magnetic alloy.

6. The inductor according to claim 1, wherein when the number of turns of the coil is 1 and the maximum current is 3A, the ratio of the inductance L of the inductor to the maximum magnetic induction Bm of the magnetic film layer is in the range of 3.8nH/T and L/Bm and 18.1 nH/T.

7. The inductor according to claim 1, further comprising a magnetic glue layer disposed between the coil layer and a magnetic film layer; the magnetic permeability of the magnetic film layer is larger than that of the magnetic glue layer.

8. The inductor according to claim 7, wherein the magnetic adhesive layer comprises a resin and magnetic particles, the magnetic particles being dispersed in the resin; the resin comprises at least one of epoxy resin, polyurethane and acrylate; the magnetic particles comprise at least one of ferrite particles, magnetic metal particles and magnetic alloy particles; the ferrite comprises at least one of MnZn ferrite and NiZn ferrite; the magnetic metal particles comprise at least one of iron, cobalt and nickel; the magnetic alloy particles comprise at least one of iron-based crystalline alloy, iron-based amorphous alloy and cobalt-based amorphous alloy; the iron-based crystalline alloy comprises at least one of FeNi alloy, FeCo alloy, FeAl alloy, FeSiAl alloy, FeNiMo alloy and FeC alloy; the iron-based amorphous alloy comprises at least one of FeSiB alloy, FeB alloy, FeNiPB alloy and FeNiMoB alloy; the cobalt-based amorphous alloy comprises at least one of a CoFeSiB alloy, a CoFeCrSiB alloy and a CoNiFeSiB alloy.

9. The inductor of claim 7, further comprising an insulating layer disposed between the coil layer and the glue layer.

10. A power management chip, wherein the power management chip comprises a power circuit and the inductor of any one of claims 1-9, and the inductor is electrically connected to the power circuit.

11. A circuit board integrated inductor, comprising:

12. The circuit board integrated inductor of claim 11, wherein the skin depth δ of the magnetic film layer is in the range of 8.4 μm δ 103 μm at a frequency of 1 MHz; when the number of turns of the coil is 1 and the maximum current is 3A, the range of the ratio of the inductance L of the integrated inductor of the circuit board to the maximum magnetic induction intensity Bm of the magnetic film layer is 3.8nH/T and L/Bm and 18.1 nH/T.

13. The circuit board integrated inductor of claim 11, wherein the magnetic alloy is a modified magnetic alloy comprising at least one of a chromium doped iron-nickel alloy, a chromium doped iron-cobalt alloy, a chromium doped iron-silicon-aluminum alloy.

14. The integrated inductor of circuit board of claim 13, wherein the magnetic film layer comprises a magnetic film sub-layer and a metal oxide layer alternately stacked in sequence, the magnetic film sub-layer is the modified magnetic alloy layer, and the metal oxide layer comprises an oxide of at least one metal in the modified magnetic alloy.

15. The integrated inductor of circuit board of claim 11, wherein the magnetic film layer comprises an insulating sub-layer and a magnetic film sub-layer alternately stacked in sequence, the insulating sub-layer comprises at least one of silicon dioxide and aluminum oxide, and the magnetic film sub-layer comprises a magnetic alloy.

16. The circuit board integrated inductor of claim 11, further comprising a magnetic glue layer disposed between the coil and the magnetic film layer; the magnetic conductivity of the magnetic film layer is greater than that of the magnetic adhesive layer; the magnetic adhesive layer comprises resin and magnetic particles, and the magnetic particles are dispersed in the resin; in the magnetic glue layer, the weight fraction of the magnetic particles ranges from 85% to 95%; the D90 particle size range of the magnetic particles is more than or equal to 1 mu m and less than or equal to D90 and less than or equal to 10 mu m.

17. The circuit board integrated inductor according to any one of claims 11-16, wherein the circuit board comprises at least one dielectric layer and at least one conductive layer; the substrate is composed of at least one dielectric layer, the dielectric layers and the conducting layers are sequentially and alternately stacked, and the conducting layers comprise conducting wires; when the conductive layer is one layer, the wire of a single layer of the conductive layer forms the coil; when the conducting layers are multiple layers, conducting wires of any two adjacent conducting layers are electrically connected to form the coil.

18. An electronic device, characterized in that the electronic device comprises an inductor according to any of claims 1-9, or comprises a power management chip according to claim 10, or comprises a circuit board integrated inductor according to any of claims 11-17.