High-magnetic-conductance and low-loss integrally formed inductor and preparation method therefor

Abstract

The present invention relates to the technical field of inductor preparation. Provided are a high-magnetic-conductance and low-loss integrally formed inductor and a preparation method therefor. The high-magnetic-conductance and low-loss integrally formed inductor comprises a stem, a winding coil, embedded magnetic powder and pins, wherein the winding coil is wound around an outer side of the stem; the pins are spot-welded and connected to both ends of the winding coil; the winding coil and the pins form a conductive ring frame; and the embedded magnetic powder is filled in the peripheral side of the conductive ring frame, and forms an integrally formed structure together with the conductive ring frame by means of a constant pressure. The present invention overcomes the defect in the prior art of the electromagnetic characteristics of an integrally formed inductor being poor, improves the high-magnetic-conductance and low-loss characteristics of the integrally formed inductor, and improves the performance and reliability of products.

Description

A high magnetic permeability and low loss integrated molded inductor and its preparation method Technical Field

[0001] The present invention belongs to the technical field of inductor devices, and in particular relates to a high-permeability, low-loss, integrally formed inductor and a preparation method thereof. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] In recent years, the trend toward thinner, lighter, and more integrated electronic devices has necessitated a shift to electronic circuitry upgrades. High energy efficiency and high current capability have become competitive advantages for these products. To meet these market demands, inductor manufacturing technology has become increasingly advanced, with product practicality and reliability increasing. One-piece molded inductors have become a hallmark of technological advancement in the inductor industry. Compared to traditional inductors, one-piece molded inductors offer smaller size, higher current capability, higher temperature resistance, lower parasitic capacitance, higher dimensional accuracy, and higher yield rates. They also exhibit high stability in high-frequency and high-temperature environments.

[0004] In current research, at the structural design level, most designers are constantly upgrading the device structure with the goals of simple structure, cost savings, and high manufacturing efficiency. For the design of I-shaped inductors, KR 2020090004493 U, KR 1020190085828 A, CN 108565994 A and CN 200941331 Y all use a T-core core column and a winding coil for simple assembly, making the prepared I-shaped inductor easy to install and with high inductance accuracy. However, they do not consider problems such as aging failure caused by exposed coils and magnetic flux leakage in the excitation field; CN 110718386 A optimizes the winding mode of the T-core inductor and adopts a flat coil for an α winding mode, thereby improving the saturation value of the device and the product yield; for the design of one-piece molded inductors, CN 1019786066 A and CN 109741918 A use the same magnetic material to prepare a T-core core column and an external casing for assembly to prepare a new type of inductor. This type of inductor has a simple structure, low cost, and high magnetic permeability. However, since the T-core core column is formed by powder metallurgy die-casting, this type of core column has a large porosity, which is far inferior to the high-density column block prepared by sintering, so there is limited room for improving the magnetic properties.

[0005] CN 104240898 A is a relatively ideal inductor design, consisting primarily of a T-shaped core rod, coil, electrodes, and an outer cladding layer. The T-core is typically made of iron-based alloy powder or ferrite metal powder, while the outer cladding layer is made of insulated metal magnetic powder. The core rod and outer cladding layer can be made of the same or different materials. The core rod is fully embedded within the inner diameter of the coil, while the electrode terminals are extended and bent and attached to the surface of the outer cladding layer, offering advantages in improved inductor performance and manufacturability. KR 100764555 B1 utilizes a ferrite core rod as the T-core and manufactures the inductor by die-casting the outer surface with magnetic powder and a base, further improving the inductor's performance. However, the device lacks annealing heat treatment, and residual compression stress within the device affects its stability.

[0006] In summary, traditional one-piece molded inductors are often die-cast from a single magnetic powder. This technical drawback lies in product density limitations and residual die-casting stress, resulting in no significant improvement in key inductor characteristics, particularly inductance, saturation current, electromagnetic loss, and reliability. Furthermore, the magnetic flux distribution within the inductor is uneven, often leading to magnetic flux leakage.

[0007] Summary of the Invention

[0008] To overcome the above-mentioned deficiencies of the prior art, the present invention provides a high-magnetic-permeability, low-loss one-piece molded inductor and a method for preparing the same, which overcomes the deficiencies of the prior art in the poor electromagnetic properties of the one-piece molded inductor, improves the high-magnetic-permeability and low-loss properties of the one-piece molded inductor, and improves product performance and reliability.

[0009] To achieve the above objectives, one or more embodiments of the present invention provide the following technical solutions:

[0010] A first aspect of the present invention provides a high-permeability, low-loss, one-piece molded inductor.

[0011] A high-magnetic-permeability, low-loss, integrally molded inductor comprises a core column, a wound coil, embedded magnetic powder, and pins. The wound coil is wound around the outside of the core column, and both ends of the wound coil are spot-welded to pins. The wound coil and the pins form a conductive coil frame. The embedded magnetic powder is filled around the conductive coil frame and is integrally molded with the conductive coil frame under constant pressure.

[0012] Preferably, the core column is a column made by sintering Mn-Zn ferrite powder; the embedded magnetic powder is made by coating magnetic metal powder with insulating material.

[0013] A second aspect of the present invention provides a method for preparing a high-permeability, low-loss, integrally formed inductor.

[0014] A method for preparing the high magnetic permeability and low loss integrally formed inductor according to the first aspect comprises the following steps:

[0015] (1) Mn-Zn ferrite powder is sintered in a N2 atmosphere at 700-900°C to obtain a ferrite core column with a relative sintering density higher than 98%;

[0016] (2) Making winding coils and winding the winding coils evenly on the core column;

[0017] (3) spot welding the wound coil to the tinned copper pin to form a conductive ring frame, and placing the welded conductive ring frame into the middle of the mold;

[0018] (4) Using inorganic-organic composite coating method to embed magnetic powder on the conductive ring frame;

[0019] (5) The conductive coil frame embedded with magnetic powder is placed in a mold to form an integrally formed inductor component.

[0020] Preferably, the embedded magnetic powder is composed of one of the following: carbonyl iron powder, iron-silicon-chromium alloy powder, and FeSiBCr amorphous powder, or a composite of two of the three powders. The atomic percentage composition of the carbonyl iron powder is: 99.5% to 99.9% Fe; the atomic percentage of the iron-silicon-chromium alloy powder is: 87.80% to 91.75% Fe, 3.65 to 8.20% Si, 4.00 to 6.00% Cr; the atomic percentage of the FeSiBCr amorphous powder is: 71.10% Fe, 8.94% Si, 14.96% to 16.89% B, 3.07 to 5.00% Cr.

[0021] Preferably, the inorganic-organic composite coating method comprises the following steps: passivating the surface of the weighed magnetic powder with phosphoric acid, adding an organic binder to the dry magnetic powder after phosphating, mixing the powder evenly, drying the powder, screening the powder and granulating the powder.

[0022] Preferably, the mass percentage of the phosphoric acid is 0.5-1.5%, and the phosphating time is 2 hours; the mass percentage of the organic binder is 1%-5%; the mesh range of the sieving and granulation is 40-200 mesh; the lubricant is barium stearate or zinc stearate, and the amount used is 1-3wt.‰ of the total mass percentage of the magnetic powder.

[0023] Preferably, after step five, the method further includes step six: subjecting the integrally formed inductor component to an annealing heat treatment, wherein the annealing temperature is within 220 degrees and the holding time is between 60-120 minutes.

[0024] Preferably, after step six, the method further includes: cutting and bending the tinned copper pins on both sides of the integrally formed inductor component.

[0025] Preferably, the ferrite powder is prepared by co-precipitation method and includes three types of oxides: MnO, ZnO, and Fe2O3.

[0026] Preferably, the wound coil is a round wire, a twisted wire or a flat spiral coil, and the coil surface is insulated with insulating varnish.

[0027] One or more of the above technical solutions have the following beneficial effects:

[0028] The present invention provides a high-permeability, low-loss, one-piece molded inductor and a preparation method thereof. The prepared one-piece molded inductor component has the characteristics of high electromagnetic properties, high strength, and easy processing; at the same time, it can shorten the device production cycle and reduce labor costs; and can maintain high stability in high-frequency and high-temperature environments.

[0029] Advantages of additional aspects of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0031] FIG1 is a perspective schematic diagram of the overall structure of an integrally formed inductor according to the present invention.

[0032] FIG2 is a front view schematic diagram of the structure of the integrally formed inductor of the present invention.

[0033] FIG3 is a schematic diagram of a top view of the structure of an integrally formed inductor according to the present invention.

[0034] FIG4 is a bottom view of the structure of the integrally formed inductor of the present invention.

[0035] FIG5 is a schematic diagram of the left side structure of the integrally formed inductor of the present invention.

[0036] FIG6 is a schematic diagram of the right side structure of the integrally formed inductor of the present invention.

[0037] FIG7 is a diagram showing the results of simulating the magnetic induction intensity distribution of the inductors prepared in Example 1, Example 2, Comparative Example 1, and Comparative Example 2 of the present invention.

[0038] In the accompanying drawings, the components represented by the reference numerals are as follows: 1 core column, 2 wound coil, 3 embedded magnetic powder, 4 pin, 5 spot welding end, 6 copper sheet slot. DETAILED DESCRIPTION

[0039] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0040] It should be noted that the terms used herein are for describing particular embodiments only and are not intended to limit the exemplary embodiments according to the present invention.

[0041] In the absence of conflict, the embodiments of the present invention and the features thereof may be combined with each other.

[0042] Overall inventive concept:

[0043] Traditional one-piece molded inductors are often die-cast from a single magnetic powder. These technical drawbacks stem from product density limitations and residual compression stress, resulting in no significant improvement in key inductor characteristics, particularly inductance, saturation current, electromagnetic loss, and reliability. Furthermore, the magnetic flux distribution within the inductor is uneven, often leading to leakage flux. Magnetic permeability and inductance are positively correlated; higher permeability results in stronger flux binding.

[0044] Therefore, the present invention proposes a high-permeability, low-loss, one-piece molded inductor and a preparation method thereof. By adding high-permeability, low-loss, and high-density sintered ferrite magnetic columns, the magnetic lines of force are concentrated and evenly distributed, thereby solving the leakage flux problem and improving the magnetic permeability of the entire inductor.

[0045] A method for preparing a novel one-piece molded inductor component comprises the following steps: (1) making a core column; (2) making a winding coil; (3) spot welding a conductive coil frame; (4) making an embedded magnetic powder; (5) integrally forming the embedded magnetic powder conductive coil frame; (6) annealing heat treatment; and (7) processing, sorting, and printing the inductor.

[0046] A first aspect of the present invention discloses a high-permeability, low-loss, integrally formed inductor.

[0047] As shown in Figures 1 to 6, a high magnetic permeability and low loss one-piece molded inductor includes a core column 1, a wound coil 2, embedded magnetic powder 3 and a pin 4. The wound coil 2 is wound on the outside of the core column 1, and both ends of the wound coil 2 are spot-welded to the pins 4. A spot welding end 5 is provided at the welding point between the wound coil 2 and the pin 4. The wound coil 2 and the pin 4 constitute a conductive coil frame, and the embedded magnetic powder 3 is filled around the conductive coil frame and is constantly pressurized to form an one-piece molded structure with the conductive coil frame.

[0048] As shown in FIG. 1 , the pin 4 is provided with a bend, which is arranged toward the direction of the wound coil 2 to form a copper sheet attachment groove 6 .

[0049] The core column is a column made by sintering Mn-Zn ferrite powder; the embedded magnetic powder is made by coating magnetic metal powder with insulating material.

[0050] A new type of integrated inductor was designed and manufactured, as shown in Figure 1. It consists of a core, a wound coil, embedded magnetic powder, and tinned copper pins. The wound coil and tinned copper are spot-welded to form a "conductive frame." The ferrite core is assembled into the core of the conductive frame, then embedded with magnetic powder and formed using constant pressure to form an integrated inductor component. The core is made of a sintered Mn-Zn ferrite powder cylinder. The embedded magnetic powder consists of magnetic metal powder coated with an insulating material.

[0051] A second aspect of the present invention discloses a method for preparing a high-permeability, low-loss, integrally formed inductor.

[0052] A method for preparing the high-permeability, low-loss, integrally formed inductor according to Example 1 comprises the following steps:

[0053] (1) Mn-Zn ferrite powder is sintered in a N2 atmosphere at 700-900°C to obtain a ferrite core column with a relative sintering density higher than 98%;

[0054] (2) Making winding coils and winding the winding coils evenly on the core column;

[0055] (3) spot welding the wound coil to the tinned copper pin to form a conductive ring frame, and placing the welded conductive ring frame into the middle of the mold;

[0056] (4) Using inorganic-organic composite coating method to embed magnetic powder on the conductive ring frame;

[0057] (5) placing the conductive coil frame embedded with magnetic powder into a mold to form an integrally formed inductor component;

[0058] (6) Annealing heat treatment;

[0059] (7) Inductor processing, inspection and printing.

[0060] The ferrite powder is prepared by coprecipitation method and mainly contains three kinds of oxides: MnO, ZnO and Fe2O3. After sintering at 700-900℃ in N2 atmosphere for 2 hours, a ferrite core column with a relative sintering density higher than 98% is obtained.

[0061] The embedded magnetic powder is composed of one of the following: carbonyl iron powder, iron-silicon-chromium alloy powder, and FeSiBCr amorphous powder, or a composite of the two. The carbonyl iron powder comprises (atomic percentage at.%) 99.5% to 99.9% Fe. The iron-silicon-chromium alloy powder comprises (atomic percentage at.%) 87.80% to 91.75% Fe, 3.65% to 8.20% Si, and 4.00% to 6.00% Cr. The FeSiBCr amorphous powder comprises (atomic percentage at.%) 71.10% Fe, 8.94% Si, 14.96% to 16.89% B, and 3.07% to 5.00% Cr.

[0062] In the step (1), the core column is made by preparing manganese zinc ferrite powder by co-precipitation method, first cold pressing it into a column embryo with certain size characteristics, and then sintering it in a heat treatment muffle furnace with a nitrogen atmosphere at a high temperature environment of 700-900°C to obtain a ferrite core column with a relative sintering density higher than 98%.

[0063] In step (2), the coil is a round wire, a stranded wire or a flat spiral coil wound evenly on the ferrite core column. The coil surface is insulated with insulating varnish to prevent short circuit.

[0064] In the step (3), the conductive coil frame is assembled by connecting the two ends of the wound coil to the tinned copper sheet by spot welding. In the step (5), the conductive coil frame embedded with magnetic powder is integrally formed by placing the spot-welded conductive coil frame into a special mold to achieve the molding effect of the coil and the embedded magnetic powder as one body.

[0065] The equipment for producing magnetic powder generally includes a melting furnace, an atomizer, and a vibrating screen. In step (4), the embedded magnetic powder is composed of one of carbonyl iron powder, iron-silicon-chromium alloy powder, and FeSiBCr amorphous powder, or a combination of two of the three. The magnetic powder is produced using an inorganic-organic composite coating method, specifically: the weighed magnetic powder is surface passivated with phosphoric acid, an organic binder is added to the dry magnetic powder after phosphating, and after uniform mixing, it is dried, sieved, and granulated. An appropriate amount of lubricant is added to the granulated powder to facilitate demolding after molding.

[0066] In one embodiment, the coating treatment method of the magnetic powder is an inorganic-organic composite coating method.

[0067] Using carbonyl iron powder and iron-silicon-chromium alloy powder as raw materials, the weighed magnetic powder is first surface-treated with a phosphoric acid solution. The phosphating agent dosage is 0.5-1.5%, and the phosphating time is controlled at 2 hours. The phosphated magnetic powder is then dried in a constant-temperature drying oven at 110°C for 1 hour. The dried phosphated magnetic powder is then added with 1%-5% by weight of an organic binder, mixed thoroughly, and then dried and sieved through a 40-200 mesh screen for granulation. The granulated powder is then lubricated with 1-3 wt.‰ of barium stearate to form an embedded magnetic powder. This embedded magnetic powder is then formed using a one-piece inductor molding process. The molded one-piece inductor is annealed at a temperature below 220°C for 60-120 minutes. Finally, the tinned copper leads on both sides of the one-piece inductor component are trimmed and bent to facilitate surface mount applications.

[0068] The following are two preferred embodiments:

[0069] Example 1:

[0070] Production size:

[0071] Inductor dimensions: length * width * height = 7.3mm * 6.8mm * 5.0mm; ferrite core column dimensions: outer diameter * height = 3.0mm * 5.0mm; winding coil wire diameter: 0.4mm; number of winding turns: 20Ts.

[0072] The embedded powder is made from carbonyl iron powder (measured by mass). The weighed carbonyl iron powder is surface-treated with a phosphoric acid solution, using a phosphating agent dosage of 0.7% to 1.0% for a phosphating time of 2 hours. The phosphated magnetic powder is then dried in a 110°C constant-temperature drying oven for 1 hour. A 4% organic binder is added to the dried phosphated magnetic powder, mixed thoroughly, and then dried and sieved through a 40-200 mesh screen for granulation. 3 wt.‰ of barium stearate lubricant is added to the granulated powder to produce embedded magnetic powder, which is then formed using a one-piece inductor molding process. The molded one-piece inductor undergoes a low-temperature annealing treatment at a temperature below 220°C for 120 minutes. Finally, the tinned copper leads on both sides of the one-piece inductor component are trimmed and bent to facilitate surface mount applications. The simulated inductance is 24.245 μH±20% (1 MHz 0.5 V), where the magnetic induction intensity distribution of the column is shown in FIG7( b ).

[0073] Example 2:

[0074] The production dimensions are: Inductor size: length * width * height = 7.3mm * 6.8mm * 5.0mm; Ferrite core column size: outer diameter * height = 3.0mm * 5.0mm; Winding coil wire diameter: 0.4mm; Number of winding turns:

[0075] 20Ts.

[0076] The embedded powder is made from iron, silicon, and chromium powder (measured by mass). The weighed iron, silicon, and chromium powder is surface-treated with a phosphoric acid solution. The phosphating agent dosage ranges from 0.5% to 1.5%, and the phosphating time is controlled at 2 hours. The phosphated magnetic powder is then dried in a 110°C constant-temperature drying oven for 1 hour. A 4% organic binder is added to the dried phosphated magnetic powder, mixed thoroughly, and then dried and sieved through a 40-200 mesh screen for granulation. 3 wt.‰ of barium stearate lubricant is added to the granulated powder to produce embedded magnetic powder. The embedded magnetic powder is then formed using the integrated inductor process. The formed integrated inductor undergoes a low-temperature annealing treatment at a temperature below 220°C for 120 minutes. Finally, the tinned copper leads on both sides of the integrated inductor component are trimmed and bent to facilitate surface mount applications. The simulated inductance is 30.293 μH±20% (1 MHz 0.5 V), where the magnetic induction intensity distribution of the column is shown in FIG7 (c).

[0077] At the same time, as a control group, two one-piece molded inductors of the same specifications (Control Group 1 and Control Group 2) were prepared using previous technology, that is, without including a ferrite core column, using a single embedded magnetic powder direct die-casting molding. The simulated inductance performance results under the same test conditions are as follows.

[0078] Comparative Example 1:

[0079] The simulated inductance of control group 1 (one-piece molded inductor made of carbonyl iron without ferrite core) is 9.329 μH±20% (1 MHz 0.5 V), where the magnetic induction intensity distribution of the core is shown in FIG7 (d).

[0080] Comparative Example 2: The simulated inductance of Control Group 2 (one-piece inductor made of iron, silicon and chromium without ferrite core) is 11.815 μH±20% (1MHz 0.5V), where the magnetic induction intensity distribution of the core is shown in FIG7 (e).

[0081] Table 1 summarizes the simulation results for the monolithic inductors prepared in the Examples and Comparative Examples. Furthermore, the magnetic flux density distribution results for the core pillars of the Examples and Comparative Examples clearly show that higher magnetic permeability (including ferrite core pillars) leads to higher magnetic flux density, thereby increasing the inductor's inductance and facilitating miniaturization of inductor devices.

[0082] Table 1 Simulation results of the one-piece molded inductors prepared in the examples and comparative examples

[0083] Note: Inductor dimensions: L*W*H=7.3mm*6.8mm*5.0mm; Ferrite core dimensions: OD*H=3.0mm*5.0mm; Coil wire diameter: 0.4mm; Number of turns: 20Ts.

[0084] As can be seen from the examples, the integrated molded inductor not only solves the problem of poor electromagnetic properties, but also maintains high stability of magnetic properties in high-frequency and high-temperature environments, improving product performance and reliability, while also shortening device production cycles and reducing labor costs.

[0085] Those skilled in the art will appreciate that the modules or steps of the present invention described above can be implemented using a general-purpose computer device. Alternatively, they can be implemented using program code executable by a computing device, which can then be stored in a storage device and executed by the computing device. Alternatively, they can be fabricated into separate integrated circuit modules, or multiple modules or steps can be fabricated into a single integrated circuit module for implementation. The present invention is not limited to any specific combination of hardware and software.

[0086] Although the above describes the specific embodiments of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without any creative work are still within the scope of protection of the present invention.

Claims

1. A high magnetic permeability and low loss one-piece molded inductor, characterized in that: It includes a core column, a winding coil, embedded magnetic powder and pins. The winding coil is wound on the outside of the core column. Both ends of the winding coil are spot-welded with pins. The winding coil and the pins form a conductive coil frame. The embedded magnetic powder is filled around the conductive coil frame and is formed into an integrated structure with the conductive coil frame under constant pressure.

2. The high magnetic permeability and low loss one-piece molded inductor according to claim 1, characterized in that: The core column is a column made by sintering Mn-Zn ferrite powder; the embedded magnetic powder is made by insulating material coating magnetic metal powder.

3. A method for preparing the high magnetic permeability and low loss one-piece molded inductor according to any one of claims 1 to 2, characterized in that: The following steps are involved: (1) Mn-Zn ferrite powder is sintered in a N2 atmosphere at 700-900°C to obtain a ferrite core column with a relative sintering density higher than 98%; (2) Making winding coils and winding the winding coils evenly on the core column; (3) spot welding the wound coil to the tinned copper pin to form a conductive ring frame, and placing the welded conductive ring frame in the middle of the mold; (4) using an inorganic-organic composite coating method to embed magnetic powder on a conductive ring frame; (5) placing the conductive coil frame after embedding the magnetic powder into a mold to form an integrated molded inductor component.

4. The method for preparing a high magnetic permeability and low loss integrated molded inductor according to claim 3, characterized in that: The embedded magnetic powder is composed of one of the following three powders, carbonyl iron powder, iron silicon chromium alloy powder, and FeSiBCr amorphous powder, or a composite of two of the three powders. The atomic percentage of the carbonyl iron powder is: 99.5% to 99.9% Fe; the atomic percentage of the iron silicon chromium alloy powder is: 87.80% to 91.75% Fe, 3.65% to 8.20% Si, 4.00% to 6.00% Cr; the atomic percentage of the FeSiBCr amorphous powder is: 71.10% Fe, 8.94% Si, 14.96% to 16.89% B, 3.07% to 5.00% Cr.

5. The method for preparing a high magnetic permeability and low loss integrated molded inductor according to claim 3, characterized in that: The inorganic-organic composite coating method specifically comprises: treating the surface of weighed magnetic powder with phosphoric acid for passivation, adding an organic binder to the phosphated dry magnetic powder, mixing evenly, drying, sieving and granulating.

6. The method for preparing a high magnetic permeability and low loss integrated molded inductor according to claim 5, characterized in that: The mass percentage of the phosphoric acid is 0.5-1.5%, and the phosphating time is 2 hours; the mass percentage of the organic binder is 1%-5%; the mesh range of the sieving and granulation is 40-200 mesh; the lubricant is barium stearate or zinc stearate, and the amount used is 1-3wt.‰ of the total mass percentage of the magnetic powder.

7. The method for preparing a high magnetic permeability and low loss integrated molded inductor according to claim 3, characterized in that: After step five, the method further includes step six: subjecting the integrally formed inductor element to an annealing heat treatment, wherein the annealing temperature is within 220 degrees and the heat preservation time is between 60 and 120 minutes.

8. The method for preparing a high magnetic permeability and low loss integrated molded inductor according to claim 3, characterized in that: After step six, the method further includes: cutting and bending the tinned copper pins on both sides of the one-piece molded inductor component.

9. The method for preparing a high magnetic permeability and low loss integrated molded inductor according to claim 3, characterized in that: The ferrite powder is prepared by coprecipitation method and includes three types of oxides: MnO, ZnO and Fe2O3.

10. The method for preparing a high magnetic permeability and low loss integrated molded inductor according to claim 3, characterized in that: The winding coil is a round wire, a twisted wire or a flat spiral coil, and the coil surface is insulated with an insulating paint.

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