Differential mode and common mode integrated inductor and preparation method thereof

Abstract

The invention discloses a differential mode and common mode integrated inductor and a preparation method thereof, and belongs to the technical field of integration of electronic components. The differential mode and common mode integrated inductor comprises a differential mode inductance magnetic ring, a common mode inductance magnetic ring coaxial with the differential mode inductance magnetic ring is arranged in the differential mode inductance magnetic ring in a sleeved mode, and a coil is wound on the differential mode inductance magnetic ring. The invention further discloses a preparation method of the differential mode and common mode integrated inductor. According to the preparation method of the differential-mode and common-mode integrated inductor, the common-mode inductor magnetic ring and the differential-mode inductor magnetic ring are prepared respectively, then the common-mode inductor magnetic ring and the differential-mode inductor magnetic ring are assembled together, and potting is carried out to form the differential-mode and common-mode integrated inductor. The whole preparation process is simple, low in cost and easy to implement.

Description

Technical Field

[0001] This invention relates to the field of electronic component integration technology, specifically to a differential-mode and common-mode integrated inductor and its fabrication method. Background Technology

[0002] With the widespread application and development of power electronic equipment, especially the trend of circuit integration in new energy vehicle motor control and OBC, differential mode filter inductors and common mode filter inductors have gradually shifted from the use of independent components to the current integrated differential and common mode filter design. This integrated design not only helps to reduce the physical size of the entire circuit system and the number of inductive components on the PCBA, thus reducing the corresponding cost, but also improves the differential and common mode filtering effect in the circuit.

[0003] Existing technologies and common-mode integrated filters mainly fall into two categories: 1) Ferrite material is used, pressed and sintered, and then the air gap is cut open; to obtain the differential mode inductor function on the basis of common mode inductor; however, this type of process is long and involves multiple processing steps, with low efficiency, and due to the introduction of obvious air gap, more leakage flux is caused, which generates radiation interference and is not conducive to improving EMC performance.

[0004] 2) A closed common-mode inductor is fabricated using high-permeability materials such as nanocrystals, and a stacked magnet is placed in the middle of the common-mode inductor to form a combined type; however, the processing technology of this type of stacked magnet is complicated, requiring stamping or cutting before curing and molding, and the appearance is generally treated with epoxy spraying, and there is also an obvious air gap at the bonding position with the common-mode inductor magnetic ring; in addition, the inductance of the stacked magnet is low, and the differential-mode filtering effect is generally poor. Summary of the Invention

[0005] The purpose of this invention is to provide a differential-mode and common-mode integrated inductor and its preparation method, which solves the technical problems in the manufacturing process of existing differential-mode and common-mode integrated inductors, such as cumbersome manufacturing process, obvious air gap, and poor filtering capability of differential-mode inductors.

[0006] To achieve the above objectives, one embodiment of the present invention provides an integrated differential-mode and common-mode inductor, including a differential-mode inductor magnetic ring, inside which is a common-mode inductor magnetic ring coaxial with the differential-mode inductor magnetic ring, and a coil is wound around the differential-mode inductor magnetic ring.

[0007] In one preferred embodiment of the present invention, the differential mode inductor magnetic ring includes an annular base plate, on which a first annular vertical plate and a second annular vertical plate located inside the first annular vertical plate are disposed.

[0008] In one preferred embodiment of the present invention, a partition is provided inside the second annular vertical plate.

[0009] In one preferred embodiment of the present invention, the axis of the first annular vertical plate is the same as the axis of the second annular vertical plate.

[0010] In one preferred embodiment of the present invention, a common-mode inductor magnetic ring is sleeved on the outer wall of the second annular vertical plate.

[0011] In one preferred embodiment of the present invention, an annular sealant is provided on the common mode inductor magnetic ring.

[0012] Based on the differential-mode and common-mode integrated inductor disclosed in this invention, this invention also discloses a method for fabricating the differential-mode and common-mode integrated inductor, comprising the following steps: Common-mode and differential-mode inductor magnetic rings were fabricated separately. The prepared common-mode inductor ring and differential-mode inductor ring are assembled. After assembly, the assembled common-mode inductor ring and differential-mode inductor ring are potted. After the potting process is completed, the winding process is carried out to obtain an integrated differential mode and common mode inductor.

[0013] In one preferred embodiment of the present invention, the common-mode inductor ring includes an iron-based nanocrystalline common-mode inductor ring, an iron-based amorphous common-mode inductor ring, and a ferrite common-mode inductor ring, and the differential-mode inductor ring includes a metal powder core differential-mode inductor ring and a ferrite differential-mode inductor ring.

[0014] One preferred embodiment of the present invention is the preparation of an iron-based nanocrystalline common-mode inductor magnetic ring, which includes: performing crystallization heat treatment on a substrate, and then subjecting the iron core to magnetic field heat treatment, impregnation and curing, and baking to obtain the iron-based nanocrystalline common-mode inductor magnetic ring.

[0015] One preferred embodiment of the present invention is the preparation of an iron-based amorphous common-mode inductor magnetic ring, which includes: a substrate undergoing shaping heat treatment, stress relief heat treatment, magnetic field heat treatment, impregnation curing, and baking to obtain an iron-based amorphous common-mode inductor magnetic ring.

[0016] One preferred embodiment of the present invention is the preparation of a ferrite common mode inductor ring, comprising: ball milling ferrite raw materials and additives, pre-firing and ball milling the milled material to obtain powder, adding binder and lubricant to the powder for granulation, and pressing and sintering the granulated powder to obtain a ferrite common mode inductor ring.

[0017] One preferred embodiment of the present invention is the preparation of a metal powder core differential mode inductor magnetic ring, which includes: passivating and granulating the raw material powder, and then pressing and stress-relieving heat treatment of the granulated powder to obtain a metal powder core differential mode inductor magnetic ring.

[0018] In one preferred embodiment of the present invention, the common-mode inductor ring and the differential-mode inductor ring after potting are insulated before the winding process.

[0019] In one preferred embodiment of the present invention, the insulation treatment includes packaging and / or coating.

[0020] In summary, the beneficial effects of the present invention are as follows: 1. The differential-mode and common-mode integrated inductor of the present invention is a simple assembly of a common-mode inductor magnetic ring and a differential-mode inductor magnetic ring after they are separately formed, which is lower in cost and easier to implement.

[0021] 2. The differential-mode inductor magnetic ring in this invention, through adjustment of material composition, possesses stronger anti-saturation capability and greater differential-mode filtering capability. Among them, the powder core magnetic ring (iron powder core, iron-silicon-aluminum powder core, iron-silicon powder core, iron-nickel powder core, iron-nickel-molybdenum powder core, amorphous powder core, nanocrystalline powder core, etc.) has a permeability of 10-200. Different powder core compositions have different anti-saturation capabilities, different losses, and different costs. Different compositions can be selected according to actual needs.

[0022] 3. In the differential-mode and common-mode integrated inductor of this invention, there is no gap in the magnetic circuit of the differential-mode inductor magnetic ring, resulting in lower leakage flux and better differential-mode filtering effect.

[0023] 4. This invention's integrated differential-mode and common-mode inductor improves the saturation current capability of the common-mode inductor ring through the structural design of both the common-mode and differential-mode inductor rings, thereby avoiding the risk of common-mode inductor ring saturation when ripple current in the circuit increases abnormally. When the common-mode inductor ring performs common-mode filtering, the differential-mode inductor ring, while generating its own differential-mode filtering, also participates in the common-mode inductor filter, sharing the saturation problem caused by the common-mode inductor ring.

[0024] 5. The method for preparing the differential-mode and common-mode integrated inductor of the present invention involves preparing a common-mode inductor magnetic ring and a differential-mode inductor magnetic ring separately, and then assembling the prepared common-mode inductor magnetic ring and differential-mode inductor magnetic ring together and potting them to obtain a differential-mode and common-mode integrated inductor. The resulting differential-mode and common-mode integrated inductor has a high degree of integration and is safer to use in harsh mechanical stress environments such as automotive applications.

[0025] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention will be apparent from the effects described in the description and the accompanying drawings. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of the integrated differential-mode and common-mode inductor in an embodiment of the present invention; Figure 2 This is an exploded view of the integrated differential-mode and common-mode inductor in an embodiment of the present invention; Figure 3This is a flowchart of the method for preparing the integrated differential-mode and common-mode inductor in an embodiment of the present invention.

[0027] Among them, 1-differential mode inductor magnetic ring, 2-sealant, 3-coil, 4-common mode inductor magnetic ring, 5-first annular vertical plate, 6-second annular vertical plate, 7-partition plate, 8-annular base plate. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] The endpoints and any values ​​of the ranges disclosed in this invention are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this invention.

[0030] This invention provides an integrated differential-mode and common-mode inductor, comprising a differential-mode inductor ring 1, inside which is a common-mode inductor ring 4 coaxial with the differential-mode inductor ring 1. Two coils 3 are wound around the differential-mode inductor ring 1. The differential-mode inductor ring 1 is made of high-saturation ferrite, magnetic powder cores of various alloy compositions, etc.; the common-mode inductor ring 4 is made of iron-based nanocrystalline, iron-based amorphous, or high-permeability magnetic ferrite. The coils 3 are made of copper wire, which can be round or flat.

[0031] The differential mode inductor magnetic ring 1 includes an annular base plate 8, on which a first annular vertical plate 5 and a second annular vertical plate 6 located inside the first annular vertical plate 5 are provided. The axis of the first annular vertical plate 5 is the same as the axis of the second annular vertical plate 6, and a partition 7 is provided inside the second annular vertical plate 6. The partition 7 is provided to divide the cavity inside the second annular vertical plate 6 into two parts, which facilitates the subsequent winding of the coil 3.

[0032] Furthermore, the common-mode inductor ring 4 is fitted onto the outer wall of the second annular plate 6, meaning the common-mode inductor ring 4 is inserted into the cavity formed between the first annular plate 5 and the second annular plate 6 in the differential-mode inductor ring 1. An annular sealant 2 is also provided on the common-mode inductor ring 4. The annular sealant 2 is used to seal the differential-mode inductor ring 1 and the common-mode inductor ring 4. The annular sealant 2 can be made of materials such as epoxy resin, silicone, or polyurethane.

[0033] Preferably, a protective box is also provided between the differential mode inductor magnetic ring 1 and the coil 3. The protective box serves to protect and insulate the coil. The material of the protective box is PPS (polyphenylene sulfide), PET (polyethylene terephthalate), PBT (polybutylene terephthalate), etc.

[0034] The differential-mode and common-mode integrated inductor of the present invention is obtained by assembling a common-mode inductor magnetic ring 4 with a differential-mode inductor magnetic ring 1, and the common-mode inductor magnetic ring 4 is inserted into the cavity formed between the first annular plate 5 and the second annular plate 6 in the differential-mode inductor magnetic ring 1.

[0035] In this invention, the differential-mode inductor magnetic ring 1 of the integrated differential-mode and common-mode inductor has no gaps in its magnetic circuit, resulting in lower leakage flux and better differential-mode filtering performance. In many current patents, the differential-mode inductor magnetic ring 1 and the common-mode inductor magnetic ring 4 share a portion of their magnetic circuit. However, due to physical size limitations, the magnetic circuit of the differential-mode inductor magnetic ring 1 and the shared magnetic circuit inherently have air gaps. This patent eliminates this problem; the magnetic circuit of the differential-mode inductor magnetic ring 1 is continuous, resulting in even lower leakage flux.

[0036] The common-mode inductor ring 4 of this invention, which integrates differential-mode and common-mode inductors, exhibits significantly improved saturation current, mitigating the risk of saturation of the common-mode inductor ring 4 when ripple current abnormally increases in the circuit. This invention primarily achieves higher saturation current capability through the structural design of the common-mode inductor ring 4 and the differential-mode inductor ring 1. When the common-mode inductor ring 4 performs common-mode filtering, the differential-mode inductor ring 1, while generating its own differential-mode filtering, also participates in the common-mode inductor filter, thus sharing the saturation problem caused by the common-mode inductor ring 4.

[0037] Based on the differential-mode and common-mode integrated inductor disclosed in this invention, this invention also discloses a method for fabricating the differential-mode and common-mode integrated inductor, comprising the following steps: Step (1): Prepare common-mode inductor ring 4 and differential-mode inductor ring 1 respectively; specifically, common-mode inductor ring 4 includes iron-based nanocrystalline common-mode inductor ring, iron-based amorphous common-mode inductor ring and ferrite common-mode inductor ring, and differential-mode inductor ring 1 includes metal powder core differential-mode inductor ring and ferrite differential-mode inductor ring; The preparation of the iron-based nanocrystalline common-mode inductor ring includes: crystallization heat treatment of the substrate, magnetic field heat treatment of the iron core, impregnation and curing, and baking to obtain the iron-based nanocrystalline common-mode inductor ring; specifically, the preparation method of the iron-based nanocrystalline common-mode inductor ring is to use a thin strip of 1K107 composition system, wind it into a certain size (ring), and then directly crystallize it (heat treatment temperature 520-590℃, holding time 30-300min). If it is a closed shape such as a racetrack or rectangle, it is first subjected to shaping heat treatment (heat treatment temperature 350- The iron core is heated to 500℃ for 30-300 minutes, and then subjected to crystallization heat treatment. After crystallization heat treatment, the core is subjected to magnetic field heat treatment (heat treatment temperature 350-550℃, holding time 30-300 minutes, magnetic field 10mT-300mT). After impregnation and curing, epoxy resin, silicone, polyurethane and other adhesives are selected and diluted. The ratio of resin to diluent is between 1:10 and 1:500. After impregnation for 3-180 seconds, the core is baked in an oven at 50-180℃ for 10-200 minutes to obtain an iron-based nanocrystalline common mode inductor ring. The preparation of iron-based amorphous common-mode inductor magnetic rings includes: a substrate undergoing shaping heat treatment, stress-relief heat treatment, magnetic field heat treatment, impregnation curing, and baking to obtain the iron-based amorphous common-mode inductor magnetic ring; specifically, the preparation method of the iron-based amorphous common-mode magnetic ring is to use a thin strip of 1K101 composition system, wind it into a certain size (ring), and then first perform shaping heat treatment (heat treatment temperature 250-350℃, holding time 30-300min), followed by stress relief. Heat treatment, followed by magnetic field heat treatment (heat treatment temperature 350-450℃, holding time 30-300min, magnetic field 10mT-300mT); impregnation and curing, using epoxy resin, silicone, polyurethane and other adhesives and diluting them, with the resin to diluent ratio between 1:10 and 1:500, impregnating for 3s-180s, and then baking in an oven at 50-180℃ for 10-200min to obtain an iron-based amorphous common-mode inductor ring; The preparation of ferrite common-mode inductor magnetic rings includes: ball milling ferrite raw materials and additives; pre-calcining and secondary ball milling of the ball-milled material to obtain powder; adding binders and lubricants to the powder for granulation; and pressing and sintering the granulated powder to obtain ferrite common-mode inductor magnetic rings. Specifically, the preparation method of ferrite common-mode magnetic rings involves selecting manganese-zinc (iron oxide, manganese oxide, zinc oxide), nickel-zinc (nickel oxide, zinc oxide, copper oxide), and iron-poor ferrite raw materials, and adding small amounts of silicon oxide, calcium oxide, etc., and ball milling them in a specific ratio (ball milling speed 10-100 rpm). The powder is first sintered at a rate of d / min and a time of 10-200 min, then mixed. The mixed powder is then pre-fired (temperature 800-1200℃, time 1-10h). Next, it undergoes a second ball milling process for fine grinding to obtain 0.1-10µm powder. Then, it is granulated with the addition of binders and lubricants. The granulated powder is then pressed in ring-shaped, racetrack-shaped, or rectangular molds (unit pressure 100-3000MPa) to form a rough blank. Finally, it is sintered (temperature 800-1500℃, time 1-10h) to obtain a ferrite common-mode inductor ring. The preparation of a metal powder core differential mode inductor magnetic ring includes: passivating and granulating the raw material powder; pressing and stress-relief heat treatment of the granulated powder to obtain the metal powder core differential mode inductor magnetic ring; specifically: the preparation method of the metal powder core differential mode magnetic ring is to select single powder raw materials such as iron-silicon-aluminum, iron-silicon, iron-nickel, amorphous, nanocrystalline, or multiple powder raw materials with different compositions, first mix them according to particle size ratio, then perform insulating coating, passivate and granulate the powder with acidic reagents (phosphoric acid, oxalic acid, hydrochloric acid, etc.) at a certain concentration (0.1%-5%), add binders (cyanate ester, phenolic resin, epoxy resin, inorganic silicon solution, etc.) and lubricants (zinc stearate, lithium stearate, etc.), and then press the granulated powder in a mold of a specific shape (unit pressure of 100-3000MPa) to form a blank; then perform stress-relief heat treatment (temperature 400-900℃, time 1-10h) to obtain the metal powder core differential mode inductor magnetic ring. The preparation of ferrite differential mode inductor magnetic rings includes: selecting manganese-zinc (iron oxide, manganese oxide, zinc oxide), nickel-zinc (nickel oxide, zinc oxide, copper oxide), and iron-poor ferrite raw materials, and adding a small amount of silicon oxide, calcium oxide, etc., and ball milling (ball milling speed 10-100 rad / min, time 10-200 min) and mixing them according to a specific ratio; the mixed powder is then pre-fired (temperature 800-1200℃, time 1-10 h); then ball milled a second time for fine grinding to obtain 0.1-10 μm powder; then granulated, with the addition of binders, lubricants, etc.; then the granulated powder is pressed in ring, racetrack-shaped, rectangular, etc. molds (unit pressure 100-3000 MPa) to form a rough blank; then sintered (temperature 800-1500℃, time 1-10 h) to obtain ferrite differential mode inductor magnetic ring 1; Step (2): Assemble the common-mode inductor ring 4 and the differential-mode inductor ring 1. Specifically, according to the predetermined performance indicators, select one of the common-mode inductor ring 4 and one of the differential-mode inductor ring 1 for assembly. One common-mode inductor ring 4 is paired with one differential-mode inductor ring 1. The common-mode inductor ring 4 is installed into the corresponding cavity position of the differential-mode inductor ring 1. Step (3): After assembly, potting treatment is performed on the assembled common mode inductor ring 4 and differential mode inductor ring 1; specifically, after assembly, potting treatment is performed on the corresponding cavity position of the common mode inductor ring 4, and the potting adhesive is epoxy resin, silicone, polyurethane, etc. Step (4): After the potting process is completed, the winding process is carried out to obtain the differential mode and common mode integrated inductor; specifically, after the potting process is completed, the coil 3 is wound outside the differential mode inductor magnetic ring 1 to obtain single-phase, three-phase and four-phase differential and common mode integrated inductors. Preferably, before the winding process, the common-mode inductor ring 4 and the differential-mode inductor ring 1 after potting are insulated. The insulation process includes encapsulation and / or coating, that is, the common-mode inductor ring 4 and the differential-mode inductor ring 1 after potting are installed as a whole inside the protective box, or a coating is sprayed on the outside of the common-mode inductor ring 4 and the differential-mode inductor ring 1 after potting.

[0038] The method for fabricating the integrated differential-mode and common-mode inductor of this invention involves separately fabricating a common-mode inductor magnetic ring 4 and a differential-mode inductor magnetic ring 1, then assembling the common-mode inductor magnetic ring 4 and the differential-mode inductor magnetic ring 1 together and encapsulating them to form an integrated differential-mode and common-mode inductor. The entire fabrication process is simple, low-cost, and easy to implement.

[0039] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A differential-mode and common-mode integrated inductor, characterized in that: It includes a differential-mode inductor magnetic ring, inside which is a common-mode inductor magnetic ring coaxial with the differential-mode inductor magnetic ring, and the differential-mode inductor magnetic ring is wound with a coil.

2. The differential-mode and common-mode integrated inductor as described in claim 1, characterized in that: The differential mode inductor magnetic ring includes an annular base plate, on which a first annular upright plate and a second annular upright plate located inside the first annular upright plate are disposed.

3. The differential-mode and common-mode integrated inductor as described in claim 2, characterized in that: The second annular vertical plate has a partition inside.

4. The differential-mode and common-mode integrated inductor as described in claim 2, characterized in that: The axis of the first annular vertical plate is the same as the axis of the second annular vertical plate.

5. The differential-mode and common-mode integrated inductor as described in claim 2, characterized in that: The common-mode inductor magnetic ring is sleeved on the outer wall of the second annular vertical plate.

6. The differential-mode and common-mode integrated inductor as described in claim 1, characterized in that: The common-mode inductor magnetic ring is provided with annular sealant.

7. A method for fabricating an integrated differential-mode and common-mode inductor according to any one of claims 1-6, characterized in that, Includes the following steps: Common-mode and differential-mode inductor magnetic rings were fabricated separately. The prepared common-mode inductor ring and differential-mode inductor ring are assembled. After assembly, the assembled common-mode inductor ring and differential-mode inductor ring are potted. After the potting process is completed, the winding process is carried out to obtain an integrated differential mode and common mode inductor.

8. The method for fabricating an integrated differential-mode and common-mode inductor as described in claim 7, characterized in that: The common-mode inductor rings include iron-based nanocrystalline common-mode inductor rings, iron-based amorphous common-mode inductor rings, and ferrite common-mode inductor rings; the differential-mode inductor rings include metal powder core differential-mode inductor rings and ferrite differential-mode inductor rings.

9. The method for fabricating an integrated differential-mode and common-mode inductor as described in claim 8, characterized in that: The preparation of the iron-based nanocrystalline common-mode inductor magnetic ring includes: performing crystallization heat treatment on the substrate, and then subjecting the iron core to magnetic field heat treatment, impregnation and curing, and baking to obtain the iron-based nanocrystalline common-mode inductor magnetic ring.

10. The method for fabricating an integrated differential-mode and common-mode inductor as described in claim 8, characterized in that: The preparation of the iron-based amorphous common-mode inductor magnetic ring includes: the substrate undergoing shaping heat treatment, stress relief heat treatment, magnetic field heat treatment, impregnation curing, and baking to obtain the iron-based amorphous common-mode inductor magnetic ring.

11. The method for fabricating an integrated differential-mode and common-mode inductor as described in claim 8, characterized in that: The preparation of the ferrite common mode inductor ring includes: ball milling ferrite raw materials and additives, pre-firing and ball milling the milled material to obtain powder, adding binder and lubricant to the powder for granulation, and pressing and sintering the granulated powder to obtain the ferrite common mode inductor ring.

12. The method for fabricating an integrated differential-mode and common-mode inductor as described in claim 8, characterized in that: The preparation of the metal powder core differential mode inductor magnetic ring includes: passivating and granulating the raw material powder, and then pressing and stress-relieving heat treatment of the granulated powder to obtain the metal powder core differential mode inductor magnetic ring.

13. The method for fabricating an integrated differential-mode and common-mode inductor as described in claim 7, characterized in that: Before the winding process, the common-mode inductor ring and differential-mode inductor ring after potting are insulated.

14. The method for fabricating an integrated differential-mode and common-mode inductor as described in claim 13, characterized in that: The insulation treatment includes packaging and / or coating.

Images