A method for preparing an integrally formed inductor

Abstract

The present invention discloses a method for preparing an integrally formed inductor, and relates to the field of magnetic electronic materials, characterized in that: Step 1: material selection, according to the requirements of the use frequency (0.1-20MHz), inductance value, power loss, RDC and Isat of the inductor device, ultrafine carbonyl iron powder, iron silicon, iron silicon chromium, iron nickel, iron cobalt and other soft magnetic powders are selected as the basic powders of the integrally formed inductor; Step 2: screening, the soft magnetic powders with a certain particle size distribution are screened out by screening mechanism and powder grading technology. The present invention innovatively proposes a metal soft magnetic alloy-soft ferrite in-situ composite technology, which not only ensures the surface insulation effect of the alloy magnetic powder, but also effectively avoids the reduction of magnetic properties, and improves the comprehensive performance of the integrally formed inductor; the present invention adopts Co trace elements to replace Fe, and improves the saturation magnetic induction intensity of the alloy; and adopts Ni, Mo and Nb to partially replace Cr, reduce the Cr element content, and improve corrosion resistance.

Description

Technical Field

[0001] The invention relates to the field of magnetic electronic materials, and in particular to a method for preparing an integrally formed inductor. Background Art

[0002] As high-speed, large-capacity 5G communication technology and third-generation semiconductor technologies such as SiC and GaN gradually become practical, electronic devices are accelerating their development in the direction of miniaturization, high frequency, high integration, multi-function and wearability. This has also put forward new requirements for electronic information materials. As soft magnetic materials and devices indispensable in the processes of electromagnetic transformation, transmission and information emission, transmission, reception, processing and recording, they face huge challenges of high frequency and low power consumption, and have become a key factor restricting the development of next-generation electronic devices. The requirements of high-speed, large-capacity information transmission and processing on electronic circuits and components in high-frequency communication equipment are mainly reflected in the following aspects: (1) The response speed should be fast and the loss should be low when processing high-frequency signals; (2) High-frequency electronic signals can cause serious electromagnetic leakage, forming electromagnetic interference to peripheral equipment and other components. In order to prevent this problem from occurring, magnetoelectric components are required to be made into closed magnetic circuits as much as possible.

[0003] However, in the preparation process of one-piece molded inductors, the powder grading technology is relatively backward. Under high frequency, the loss of soft magnetic materials is mainly determined by eddy current loss, and the powder particle size is the key factor determining the eddy current loss. In addition, the powder grading also affects the fluidity, filling type, saturation flux density and DC bias of soft magnetic materials. Therefore, accurate powder grading is the key to preparing high-performance soft magnetic materials. High-frequency soft magnetic materials have very high requirements for powder particle size, usually below 10 microns. Usually, cyclone separation technology can achieve powder particle size screening, but the accuracy is poor, and it is difficult to separate powders below 1 micron. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing an integrally formed inductor in order to solve the above problem.

[0005] To achieve the above object, the present invention provides the following technical solution: a method for preparing an integrally formed inductor,

[0006] Step 1: Material selection. According to the requirements of the operating frequency, inductance value, power loss, RDC and Isat of the inductor device, ultrafine carbonyl iron powder, iron silicon, iron silicon chromium, iron nickel and iron cobalt soft magnetic powder are selected as the basic powder of the one-piece inductor;

[0007] Step 2: Screening: Screening out soft magnetic powder with a certain particle size distribution through screening mechanism and powder grading technology;

[0008] Step 3: In-situ coating, growing a nano-scale magnetic oxide layer with insulating properties on the surface of the powder through in-situ coating technology;

[0009] Step 4: Coating resin, evenly coating the powder surface with thermosetting heat-resistant insulating resin;

[0010] Step 5: bidirectional concave die floating pressing, preparing an integrally formed inductor blank by bidirectional concave die floating pressing technology, curing at a certain temperature and releasing stress to obtain a product;

[0011] Step 6: Detection, characterize the electromagnetic characteristics of the device through high-frequency inductance test technology, high-frequency loss test technology, and high-frequency resistance test technology;

[0012] The input end of the screening mechanism is connected to a feed port, an air outlet is fixed to the top of the screening mechanism, a flip fan blade is fixed to the bottom end of the air outlet and an outer wall of a connecting ring is arranged inside the screening mechanism, a connecting frame is fixed to the bottom end of the connecting ring, a rotating rod is installed at the bottom end of the connecting frame, a rotating hammer is fixed to the outer wall of the rotating rod, a connecting hammer is connected to the bottom end of the rotating hammer, a connecting rod is arranged at the bottom end of the connecting hammer, a rotating shaft is connected to the inside of the connecting rod, a vibrating hammer is arranged at one end of the rotating shaft, a screening net is connected to the outer wall of the vibrating hammer, and a collecting ring is connected to the outer wall of the screening mechanism;

[0013] The number of the screening nets is five groups, and the filter pore sizes inside the five groups of screening nets are arranged from top to bottom according to five levels: 20-50 microns, 10-20 microns, 5-10 microns, 2-5 microns, and 0.5-2 microns;

[0014] There are five groups of collecting rings, the top and bottom ends of the five groups of collecting rings are connected to each other, two groups of collecting rings are isolated by filters, the filter holes of the internal filters of the four groups of collecting rings are 10~20 microns, 5~10 microns, 2~5 microns, and 0.5~2 microns, arranged from top to bottom in sequence, the inner wall of the collecting ring is provided with a first slide groove, and the inner wall of the screening mechanism is provided with a second slide groove that penetrates through its outer wall.

[0015] Preferably, the in-situ insulation coating technology in step three and step four is: pouring the powder into a prepared reaction solution and uniformly stirring the powder at a certain temperature; in-situ growing a highly insulating soft magnetic oxide film on the surface of the powder, then separating the powder, washing it with a solvent, and then adding a binder solution to the powder and drying it so that the binder is evenly coated on the surface of the powder.

[0016] Preferably, the input end of the feed port is connected to a cyclone separator, a one-way valve is provided inside the feed port, and a one-way valve is provided at the bottom end of the air outlet.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1 The present invention innovatively proposes a metal soft magnetic alloy-soft magnetic ferrite in-situ composite technology, which not only ensures the surface insulation effect of the alloy magnetic powder, but also effectively avoids the reduction of magnetic properties, thereby improving the comprehensive performance of the one-piece molded inductor;

[0019] The present invention adopts the trace element Co to replace Fe to improve the saturation magnetic induction intensity of the alloy; and adopts Ni, Mo and Nb to partially replace Cr to reduce the Cr element content and improve the corrosion resistance;

[0020] The multi-stage crushing method of the present invention prepares soft magnetic powder, which solves the shortcomings of irregular powder shape, easy formation of ellipsoidal particles, low fine powder content and high price.

[0021] The present invention develops a new soft magnetic powder insulation coating technology to prepare soft magnetic powder with good insulation effect, excellent magnetic properties, excellent fluidity and compressibility;

[0022] The present invention adopts a concave die floating pressing method to make the density of the magnetic core blank uniform, enhance the mechanical strength and ensure the sintering quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of the screening mechanism of the present invention;

[0024] Figure 2 It is a schematic diagram of the structure of the collecting ring of the present invention;

[0025] Figure 3 It is a schematic structural diagram of the vibration hammer of the present invention.

[0026] In the figure: 1. screening mechanism; 2. feed inlet; 3. air outlet; 4. connecting ring; 5. flip fan blade; 6. connecting frame; 7. rotating rod; 8. rotating hammer; 9. connecting hammer; 10. connecting rod; 11. rotating shaft; 12. vibrating hammer; 13. screening net; 14. collecting ring. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "set" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal connection of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. The following is an explanation of an embodiment of the present invention based on the overall structure of the present invention.

[0029] A method for preparing an integrally formed inductor is characterized by:

[0030] Step 1: Material selection. According to the requirements of the operating frequency, inductance value, power loss, RDC and Isat of the inductor device, ultrafine carbonyl iron powder, iron silicon, iron silicon chromium, iron nickel and iron cobalt soft magnetic powder are selected as the basic powder of the one-piece inductor;

[0031] Step 2: Screening: Screening out soft magnetic powder with a certain particle size distribution through the screening mechanism 1 and the powder grading technology;

[0032] Step 3: In-situ coating, growing a nano-scale magnetic oxide layer with insulating properties on the surface of the powder through in-situ coating technology;

[0033] Step 4: Coating resin, evenly coating the powder surface with thermosetting heat-resistant insulating resin;

[0034] Step 5: bidirectional concave die floating pressing, preparing an integrally formed inductor blank by bidirectional concave die floating pressing technology, curing at a certain temperature and releasing stress to obtain a product;

[0035] Step 6: Detection, characterize the electromagnetic characteristics of the device through high-frequency inductance testing technology, high-frequency loss testing technology, and high-frequency resistance testing technology.

[0036] In Example 1, the in-situ insulation coating technology in step three and step four is: pouring the powder into the prepared reaction solution and uniformly stirring the powder at a certain temperature; in-situ growing a highly insulating soft magnetic oxide film on the surface of the powder, and then separating the powder, washing it with a solvent, and then adding a binder solution to the powder and drying it so that the binder is evenly coated on the surface of the powder.

[0037] Example 2, please refer to Figure 1-Figure 3 ,, including the screening mechanism 1 in step 2, the input end of the screening mechanism 1 is connected with the feed port 2, the top of the screening mechanism 1 is fixed with an air outlet 3, the bottom of the air outlet 3 is fixed with a flip fan blade 5 on the outer wall of the screening mechanism 1 provided with a connecting ring 4, the bottom end of the connecting ring 4 is fixed with a connecting frame 6, the bottom end of the connecting frame 6 is installed with a rotating rod 7, the outer wall of the rotating rod 7 is fixed with a rotating hammer 8, the bottom end of the rotating hammer 8 is connected with a connecting hammer 9, the bottom end of the connecting hammer 9 is provided with a connecting rod 10, the inside of the connecting rod 10 is connected with a rotating shaft 11, one end of the rotating shaft 11 is provided with a vibrating hammer 12, the outer wall of the vibrating hammer 12 is connected with a screening net 13, and the outer wall of the screening mechanism 1 is connected with a collecting ring 14, so that the screening mechanism 1 can screen the raw materials.

[0038] Please refer to Figure 1 The input end of the feed port 2 is connected to a cyclone separator, a one-way valve is arranged inside the feed port 2, and a one-way valve is arranged at the bottom end of the air outlet 3 to facilitate the movement of airflow inside the screening mechanism 1.

[0039] Please refer to Figure 1 The number of screening nets 13 is five groups, and the internal filter pore sizes of the five groups of screening nets 13 are arranged from top to bottom according to five levels of 20~50 microns, 10~20 microns, 5~10 microns, 2~5 microns, and 0.5~2 microns, so as to facilitate the screening mechanism 1 to classify and screen the raw materials.

[0040] Please refer to Figure 1 and Figure 2 There are five groups of collecting rings 14, the tops and bottoms of the five groups of collecting rings 14 are connected to each other, two groups of collecting rings 14 are isolated by filters, and the filter holes of the four groups of collecting rings 14 are 10-20 microns, 5-10 microns, 2-5 microns, and 0.5-2 microns, which are arranged from top to bottom in sequence. The inner wall of the collecting ring 14 is provided with a first chute, and the inner wall of the screening mechanism 1 is provided with a second chute that penetrates to its outer wall, so that the raw materials falling into the collecting ring 14 can be screened according to the particle size.

[0041] Working principle: First, when the raw material enters the screening mechanism 1 through the cyclone separator and the feed port 2, the raw material is rotated on the inner wall of the screening mechanism 1 by the wind force output by the cyclone separator. At the same time, the wind force drives the flip blade 5 to rotate, and the rotation of the flip blade 5 drives the connecting ring 4 to rotate, thereby driving the connecting frame 6 to rotate, and the rotation of the connecting frame 6 drives the rotating hammer 8 to rotate, and the rotating hammer 8 rotates to hit the connecting hammer 9, thereby driving the connecting rod 10 to move in a fan shape, and the connecting rod 10 makes a fan-shaped movement to drive the vibrating hammer 12 to make a fan-shaped movement, thereby causing the vibrating hammer 12 to hit the screening net 13. As the feed port 2 continuously flows to the screening net The raw materials are transported inside the mechanism 1, so that part of the raw materials fall on the screening net 13. Since the filter holes of the five groups of screening nets 13 are arranged from top to bottom in five levels of 20-50 microns, 10-20 microns, 5-10 microns, 2-5 microns, and 0.5-2 microns, the raw materials can be divided into five groups. Since the shape of the screening net 13 is conical, the raw materials falling on the screening net 13 slide into the collecting ring 14. However, when some smaller particles are mixed into the collecting ring 14, they will pass through the filter net at the bottom of the collecting ring 14 and fall into the next group of collecting rings 14, so that the user can quickly and conveniently screen the raw materials.

[0042] Example 3, the surface of the split body is modified in combination with powder insulation coating, and the particle size distribution is optimized to improve its fluidity and filling properties; according to the size of the inductor, multi-unit bidirectional concave molds such as 6 particles, 12 particles, 18 particles, and 24 particles are designed and the pressurization curve is optimized; in order to make the powder evenly arranged in the inductor and reduce the friction between the powder and the coil, a certain lubricant needs to be added to avoid damage to the coil insulation layer caused by powder friction as much as possible, thereby improving the product qualification rate.

[0043] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A method for preparing an integrally formed inductor, characterized in that: Step 1: Material selection. According to the requirements of the operating frequency, inductance value, power loss, RDC and Isat of the inductor device, ultrafine carbonyl iron powder, iron silicon, iron silicon chromium, iron nickel and iron cobalt soft magnetic powder are selected as the basic powder of the one-piece inductor; Step 2: Screening: Screening out soft magnetic powder with a certain particle size distribution through the screening mechanism (1) and powder grading technology; Step 3: In-situ coating, growing a nano-scale magnetic oxide layer with insulating properties on the surface of the powder through in-situ coating technology; Step 4: Coating resin, evenly coating the powder surface with thermosetting heat-resistant insulating resin; Step 5: bidirectional concave die floating pressing, preparing an integrally formed inductor blank by bidirectional concave die floating pressing technology, curing at a certain temperature and releasing stress to obtain a product; Step 6: Detection, characterize the electromagnetic characteristics of the device through high-frequency inductance test technology, high-frequency loss test technology, and high-frequency resistance test technology; The input end of the screening mechanism (1) is connected to a feed port (2); an air outlet (3) is fixed at the top of the screening mechanism (1); a flip fan blade (5) is fixed to the bottom of the air outlet (3) and the outer wall of a connecting ring (4) is provided inside the screening mechanism (1); a connecting frame (6) is fixed to the bottom end of the connecting ring (4); a rotating rod (7) is installed at the bottom end of the connecting frame (6); a rotating hammer (8) is fixed to the outer wall of the rotating rod (7); a connecting hammer (9) is connected to the bottom end of the rotating hammer (8); a connecting rod (10) is provided at the bottom end of the connecting hammer (9); a rotating shaft (11) is connected inside the connecting rod (10); a vibrating hammer (12) is provided at one end of the rotating shaft (11); a screening net (13) is connected to the outer wall of the vibrating hammer (12); and a collecting ring (14) is connected to the outer wall of the screening mechanism (1); The number of the screening nets (13) is five groups, and the filter pore sizes inside the five groups of screening nets (13) are arranged from top to bottom in five levels: 20-50 microns, 10-20 microns, 5-10 microns, 2-5 microns, and 0.5-2 microns; The number of the collecting rings (14) is five groups, the tops and bottoms of the five groups of collecting rings (14) are connected to each other, two groups of collecting rings (14) are separated by a filter screen, the filter holes of the internal filter screens of the four groups of collecting rings (14) are arranged from top to bottom in sequence of 10-20 microns, 5-10 microns, 2-5 microns, and 0.5-2 microns, the inner wall of the collecting ring (14) is provided with a first slide groove, and the inner wall of the screening mechanism (1) is provided with a second slide groove penetrating to its outer wall.

2. The method for preparing an integrally formed inductor according to claim 1, characterized in that: The in-situ insulation coating technology in step three and step four is as follows: pouring the powder into a prepared reaction solution and uniformly stirring the powder at a certain temperature; in-situ growing a highly insulating soft magnetic oxide film on the surface of the powder, then separating the powder, washing it with a solvent, and then adding a binder solution to the powder and drying it so that the binder is uniformly coated on the surface of the powder.

3. The method for preparing an integrally formed inductor according to claim 1, characterized in that: The input end of the feed port (2) is connected to a cyclone separator, a one-way valve is arranged inside the feed port (2), and a one-way valve is arranged at the bottom end of the air outlet (3).

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