A common-mode inductor core with differential-mode interference suppression and its fabrication method

Abstract

This invention belongs to the field of soft magnetic materials technology and discloses a common-mode inductor core with differential-mode interference suppression and its preparation method. The inductor core includes a main magnetic ring wound from nanocrystalline ribbon and a magnetic component disposed within a window of the main magnetic ring. The permeability of the magnetic component is lower than that of the main magnetic ring, and both ends of the magnetic component are in contact with the main magnetic ring. The inductor core of this invention innovatively adjusts the differential-mode inductance by the difference in permeability between the main magnetic ring and the magnetic component within the window of the main magnetic ring, offering advantages in flexible structural design and performance adjustment. The magnetic component can be further fabricated by bonding multiple layers of nanocrystalline and / or amorphous ribbon after magnetic fragmentation treatment with double-sided adhesive. Its permeability can be easily adjusted by the degree of fragmentation during magnetic fragmentation treatment and the number of composite layers of nanocrystalline and / or amorphous ribbon, thereby achieving adjustment of the differential-mode inductance by the difference in permeability between the component and the main magnetic ring.

Description

Technical Field

[0001] This invention belongs to the field of soft magnetic materials technology, specifically relating to a common-mode inductor core with differential-mode interference suppression function and its preparation method. Background Technology

[0002] With the widespread application of third-generation semiconductor technology, new requirements have been put forward for the performance of various power electronic components, requiring higher power and higher frequency. Moreover, due to space limitations, the integration of magnetic components in EMC circuits is becoming increasingly higher.

[0003] Conducted interference can generally be divided into two types: common-mode interference and differential-mode interference. The circuits and solutions for their electromagnetic interference signals are different. At this time, a common-mode inductor is needed in the circuit to solve the common-mode interference problem, and a differential-mode inductor is also needed to solve the differential-mode interference problem. However, as the circuit structure becomes more and more compact, there is not enough space to install the above-mentioned multiple magnetic rings.

[0004] Patent CN 115938747 A discloses a differential and common-mode integrated filter inductor, comprising a magnetic core and two winding coils wound on the magnetic core. The magnetic core is composed of two EE-type magnetic cores arranged opposite each other. The differential-mode inductance of the integrated filter inductor is adjusted based on the air gap formed by the opposing intermediate magnetic pillars of the two EE-type magnetic cores; or the magnetic core comprises a circular magnetic ring and a sheet-like magnetic core, the sheet-like magnetic core passing through the center of the circular magnetic ring and having both ends connected to the circular magnetic ring, its differential-mode inductance being set by adjusting the number and size of the inserted sheet-like magnetic cores. However, the shape of the magnetic core is relatively limited, only EE-type or circular magnetic cores are allowed, and the differential-mode inductance is adjusted by the air gap between the EE-type magnetic cores or the number and size of the inserted sheet-like magnetic cores, limiting the flexibility of its structural design and performance adjustment.

[0005] Patent CN 116864283 A discloses a common-differential mode inductor core, which achieves common-mode / differential-mode integration by placing magnetic conductors between the coils of a ring-shaped magnetic core. Patent CN 210667963 U discloses a common-mode inductor with built-in differential-mode effect, which eliminates differential-mode interference by placing a magnetic sheet in the middle of the main magnetic core, forming a magnetic shunt in the middle of the main magnetic core. Both of these patents adjust the differential-mode inductance by adjusting the gap between wedge-shaped or vertical magnetic conductors, or the gap between the magnetic sheet and the magnetic core, thus limiting the flexibility of structural design and performance adjustment. Summary of the Invention

[0006] To address the shortcomings and deficiencies of the existing technologies, the primary objective of this invention is to provide a common-mode inductor core with differential-mode interference suppression capabilities. The inductor core of this invention innovatively adjusts the differential-mode inductance by utilizing the permeability difference between the main magnetic ring and the magnetic components within the main magnetic ring window, offering advantages in both structural design and performance adjustment flexibility.

[0007] Another object of the present invention is to provide a method for preparing the above-mentioned common-mode inductor core with differential-mode interference suppression function.

[0008] The objective of this invention is achieved through the following technical solution:

[0009] A common-mode inductor core with differential-mode interference suppression capability includes a main magnetic ring wound from nanocrystalline ribbon and a magnetic component disposed within a window of the main magnetic ring; the magnetic permeability of the magnetic component is lower than that of the main magnetic ring, and both ends of the magnetic component are in contact with the main magnetic ring.

[0010] Furthermore, the main magnetic ring is a closed magnetic circuit in the shape of a ring, racetrack, rectangle, ellipse, etc.

[0011] Furthermore, the main magnetic ring is composed of Fe. bal. M a Cu b M' c Si d B e X f Iron-based nanocrystalline and / or amorphous ribbons; wherein M is Co and / or Ni, M' is at least one of Nb, V, Ta, Mo, and X is at least one of common impurity elements such as C, O, Si, N, S, P, etc.; a = 0–30%, b = 0.5–2%, c = 2–7%, d = 5–18%, e = 5–10%, f = 0–0.5%.

[0012] More preferably, in the composition of the iron-based nanocrystalline ribbon, a = 0-12%, b = 0.8-1.2%, c = 2-4%, d = 15-16%, e = 6-8%, and f = 0-0.2%.

[0013] Furthermore, the number of magnetic components is one or more; the shape of the magnetic components can be a strip, a broken line, a wedge, a trapezoid, or an S-shape with a certain width. The magnetic components can be positioned through or away from the center of the main magnetic ring; their distribution can be uniform or non-uniform, allowing for more flexible structural design and performance adjustment. For example, when there are multiple magnetic components, they can be arranged in symmetrical or asymmetrical patterns such as triangles, quadrilaterals, or pentagons around the main magnetic ring.

[0014] Furthermore, the magnetic component material may be selected as nanocrystalline and / or amorphous or ferrite material; the ferrite material may be manganese-zinc ferrite or nickel-zinc ferrite.

[0015] More preferably, the magnetic component is made of multilayered, magnetically fragmented nanocrystalline and / or amorphous ribbons bonded together with double-sided adhesive; the nanocrystalline and / or amorphous ribbons are composed of Fe. bal. Cu x Nb y Si z B n Where x = 0.8–1.2%, y = 2–4%, z = 15–16%, and n = 6–8%. The magnetic component of this invention is a multilayer nanocrystalline and / or amorphous ribbon bonded together with double-sided adhesive after magnetic fragmentation treatment. The permeability can be easily adjusted by the degree of fragmentation during magnetic fragmentation and the number of composite layers of the nanocrystalline and / or amorphous ribbon, thereby adjusting the differential mode inductance based on the permeability difference with the main magnetic ring. This offers advantages such as convenient performance adjustment and minimal restrictions on structural placement. The magnetic fragmentation process of the nanocrystalline and / or amorphous ribbon is a commonly used technique in the field, primarily used to adjust the permeability, magnetic loss, and other magnetic properties of the nanocrystalline and / or amorphous ribbon. The magnetic fragmentation treatment can be performed using transverse or longitudinal roller shearing, rolling with a round roller or flat plate with protrusions, or other methods that can induce uniform fragmentation in the nanocrystalline ribbon. The size of the fragmented nanocrystalline and / or amorphous material layers after magnetic fragmentation treatment is 0.1–3 mm; the width of the fragmentation gaps is 0.02–10 μm.

[0016] Furthermore, the relative initial permeability of the main magnetic ring is 2 to 200,000, and its effective permeability at 100 kHz is 15,000 to 60,000; the relative initial permeability of the magnetic component is 100 to 30,000, and its effective permeability at 100 kHz is 100 to 30,000.

[0017] The method for preparing the above-mentioned common-mode inductor core with differential-mode interference suppression includes the following preparation steps:

[0018] (1) The composition is Fe bal. M a Cu b M' c Si d B e X fIron-based nanocrystalline ribbons are wound into closed magnetic circuit cores, and after heat treatment for crystallization annealing, they are impregnated and cured with epoxy resin to obtain the main magnetic ring; wherein M is Co and / or Ni, M' is at least one of Nb, V, Ta, Mo, and X is at least one of common C, O, Si, N, S, P impurity elements; a = 0-30%, b = 0.5-2%, c = 2-7%, d = 5-18%, e = 5-10%, f = 0-0.5%;

[0019] (2) The composition is Fe bal. Cu x Nb y Si z B n After heat treatment and crystallization annealing, the iron-based nanocrystalline ribbon is laminated in multiple layers using pressure-sensitive double-sided adhesive. The resulting multilayer ribbon is then subjected to magnetic crushing treatment to reduce its magnetic permeability. The magnetically crushed ribbon is then die-cut to form a magnetic component; wherein x = 0.8–1.2%, y = 2–4%, z = 15–16%, and n = 6–8%.

[0020] (3) Place the main magnetic ring obtained in step (1) into the matching plastic protective box, and then insert the magnetic component obtained in step (2) into the window of the main magnetic ring. The two ends of the magnetic component are in contact with the inner wall of the main magnetic ring to obtain a common mode inductor core with differential mode interference suppression function.

[0021] Furthermore, the width of the iron-based nanocrystalline ribbon in step (1) is 1 to 100 mm and the thickness is 5 to 25 μm.

[0022] Furthermore, the temperature of the heat treatment crystallization annealing in steps (1) and (2) is 450–620 °C.

[0023] Furthermore, the epoxy resin adhesive in step (1) includes epoxy resin, low molecular weight polyamide curing agent, and diluent. By using epoxy resin, which has good insulating and bonding properties, and by using a specific low molecular weight polyamide curing agent, the stress during epoxy resin curing can be effectively reduced, the curing and bonding effect can be improved, and the inductor core can maintain its vibration-resistant stability.

[0024] Preferably, the epoxy resin is selected from type E epoxy resin, the low molecular weight polyamide curing agent is selected from 650 low molecular weight polyamide, and the diluent is at least one of anhydrous ethanol, ethyl acetate, and ethylene glycol.

[0025] Further, the impregnation and curing mentioned in step (1) refers to immersing the product in epoxy resin solution for 10s to 5min under normal pressure or vacuum conditions, then removing it and letting it drain naturally before curing it at 50 to 120℃ for 2 to 10h.

[0026] Furthermore, the width of the iron-based nanocrystalline ribbon in step (2) is 10-100 mm and the thickness is 5-25 μm.

[0027] Further, the magnetic fragmentation treatment mentioned in step (2) refers to the use of transverse or longitudinal roller shearing, rolling with a round roller or flat plate with protrusions, or other methods that can make the nanocrystalline ribbon have uniform fragmentation gaps; the size of the fragmented pieces after the magnetic fragmentation treatment is 0.1 to 3 mm; the width of the fragmentation gaps is 0.02 to 10 μm.

[0028] Compared with the prior art, the beneficial effects of the present invention are:

[0029] (1) The inductor core of the present invention adjusts the differential mode inductance by means of the difference in permeability between the main magnetic ring and the magnetic components in the window of the main magnetic ring, as well as the number and position of the magnetic components, which has the advantages of flexible structural design and performance adjustment.

[0030] (2) The main magnetic ring of the inductor core of the present invention is made of nanocrystalline strip wound together and is used after being impregnated and cured by epoxy resin with a specific composition. It can maintain the stability against vibration and the elasticity of being relatively fixed with the magnetic components at the same time.

[0031] (3) The magnetic component of the present invention can be further made by bonding nanocrystalline and / or amorphous ribbons after multi-layer magnetic crushing treatment with double-sided adhesive. The magnetic permeability can be conveniently adjusted by the degree of crushing of the magnetic crushing treatment and the number of composite layers of nanocrystalline and / or amorphous ribbons, thereby adjusting the differential mode inductance by the difference in magnetic permeability between the magnetic component and the main magnetic ring. It has the advantages of convenient performance adjustment and small restrictions on the structural position setting. Attached Figure Description

[0032] Figure 1 and Figure 2 The diagram shows the overall structure and cross-sectional structure of the inductor core obtained in Embodiment 1 of the present invention.

[0033] Figure 3 This is a schematic diagram of the structure of the inductor core obtained in Embodiment 2 of the present invention;

[0034] Figure 4 This is a schematic diagram of the structure of the inductor core obtained in Embodiment 3 of the present invention. Detailed Implementation

[0035] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0036] Example 1

[0037] (1) A nanocrystalline ribbon with a width of 10 mm and a thickness of 18 μm, the nominal composition of which is Fe bal. Cu1Nb3Si15.5 B7 (at.%) was wound into a toroidal magnetic core, crystallized and annealed at 560℃, and then vacuum-immersed in a 1:25 mixture of type E epoxy resin and 650 low molecular weight polyamide curing agent with anhydrous ethanol for 30 seconds. After being removed and allowed to air dry for 10 minutes, it was placed in a constant temperature oven at 100℃ for 5 hours to cure, resulting in the main magnetic ring. Testing showed that the relative initial permeability of the main magnetic ring was 100,000, and the effective permeability at 100kHz was 30,000.

[0038] (2) A roll of nanocrystalline ribbon with a width of 50 mm and a thickness of 18 μm, the nominal composition of which is Fe bal. Cu1Nb3Si 15.5 After B7 (at.%) is crystallized and annealed at 560℃, it is laminated with a 3μm thick pressure-sensitive double-sided adhesive. Then, the tape coated with double-sided adhesive is laminated in multiple layers to obtain a 3-layer nanocrystalline tape. The multilayer tape is then subjected to magnetic crushing (molding crushing; by adjusting the mold and pressure, the size of the fragments can be controlled to 0.5mm, and the width of the cracks to 0.1μm) to reduce its permeability. The magnetically crushed tape is then die-cut with a flat die, and through simultaneous release film removal and waste removal stacking, a stacked strip magnetic assembly with a total thickness × length × width of 5mm × 15mm × 10mm is obtained. The resulting stacked strip magnetic assembly has a relative initial permeability of 3000 and an effective permeability of 2900 at 100kHz.

[0039] (3) Place the main magnetic ring obtained in step (1) into the matching plastic protective box, and then insert the bar magnetic component obtained in step (2) into the window of the main magnetic ring. The two ends of the magnetic component are in contact with the inner wall of the main magnetic ring to obtain a common mode inductor core with differential mode interference suppression.

[0040] The overall structural schematic diagram and cross-sectional structural schematic diagram of the inductor core obtained in this embodiment are shown below. Figure 1 and Figure 2 As shown. Figure 2 Number 1 is the main magnetic ring, 2 is the magnetic component, 2-1 is the double-sided adhesive, and 2-2 is the nanocrystalline ribbon layer after magnetic crushing treatment.

[0041] Tests showed that the inductor core obtained in this embodiment has a common-mode inductance of 20μH and a differential-mode inductance of 0.45μH at a frequency of 100kHz. After applying a 10A bias current, the differential-mode inductance decreases to 0.13μH.

[0042] By controlling the degree of magnetic component fragmentation in step (2) of this embodiment and the number of composite layers of nanocrystalline ribbon, the relative initial permeability of the magnetic component was adjusted to 1000, 3000, 5000, 7000, and 10000, respectively. The effective permeability at 100kHz was 1000, 2900, 4700, 6600, and 9000, respectively. The common-mode inductance, differential-mode inductance, and differential-mode inductance attenuation of the obtained inductor core at a frequency of 100kHz were tested, and the results are shown in Table 1 below.

[0043] Table 1

[0044] test sample initial permeability 100kHz effective permeability Common mode inductance Differential mode sensitivity Differential mode inductance attenuation Test sample 1 1000 1000 20μH 0.36μH 0.17μH Test Sample 2 3000 2900 20μH 0.45μH 0.13μH Test sample 3 5000 4700 20μH 0.48μH 0.12μH Test sample 4 7000 6600 20μH 0.53μH 0.11μH Test sample 5 10000 9000 20μH 0.55μH 0.11HμH

[0045] As can be seen from the results in Table 1, the present invention can conveniently adjust the differential mode inductance and differential mode inductance attenuation by adjusting the permeability of the magnetic component, which has the advantages of convenient performance adjustment and few restrictions on the structural position setting.

[0046] Example 2

[0047] (1) A nanocrystalline ribbon with a width of 10 mm and a thickness of 18 μm, the nominal composition of which is Fe bal. Cu1Nb3Si 15.5 B7 (at.%) was wound into a racetrack-shaped magnetic core, annealed at 560℃, and then vacuum-immersed for 30 seconds using a 1:25 mixture of E-type epoxy resin and 650 low-molecular-weight polyamide curing agent (anhydrous ethanol). After being removed and allowed to air dry for 10 minutes, it was placed in a constant-temperature oven at 100℃ for 5 hours to cure, resulting in the main magnetic ring. The relative initial permeability of the main magnetic ring was tested to be 55,000, and the effective permeability at 100kHz was 25,000.

[0048] (2) A roll of nanocrystalline ribbon with a width of 50 mm and a thickness of 18 μm, the nominal composition of which is Fe bal. Cu1Nb3Si 15.5 B7 (at.%), after crystallization annealing at 560℃, is laminated with a 3μm thick pressure-sensitive double-sided adhesive. The tape coated with double-sided adhesive is then laminated in multiple layers to obtain a multi-layered nanocrystalline tape. This multi-layered tape undergoes magnetic crushing (molding crushing; by adjusting the mold and pressure, the size of the fragments can be controlled to 0.5mm, and the width of the cracks to 0.1μm) to reduce its permeability. The magnetically crushed tape is then die-cut with a flat die, and through simultaneous release film removal and waste removal stacking, a stacked strip magnetic assembly with a total thickness × length × width of 5mm × 15mm × 10mm is obtained. The resulting stacked strip magnetic assembly has a relative initial permeability of 3000 and an effective permeability of 2900 at 100kHz.

[0049] (3) Place the main magnetic ring obtained in step (1) into the matching plastic protective box, and then insert the bar magnetic component obtained in step (2) into the window of the main magnetic ring. The two ends of the magnetic component are in contact with the inner wall of the main magnetic ring to obtain a common mode inductor core with differential mode interference suppression.

[0050] A schematic diagram of the structure of the inductor core obtained in this embodiment is shown below. Figure 2 As shown.

[0051] According to the test, the inductor core obtained in this embodiment has a common-mode inductance of 21μH and a differential-mode inductance of 0.43μH at a frequency of 100kHz. After applying a bias current of 10A, the differential-mode inductance decreases to 0.15μH.

[0052] Example 3

[0053] (1) A nanocrystalline ribbon with a width of 10 mm and a thickness of 18 μm, the nominal composition of which is Fe bal. Cu1Nb3Si 15.5 B7 (at.%) was wound into a racetrack-shaped magnetic core, annealed at 560℃, and then vacuum-immersed for 30 seconds using a 1:25 mixture of E-type epoxy resin and 650 low-molecular-weight polyamide curing agent (anhydrous ethanol). After being removed and allowed to air dry for 10 minutes, it was placed in a constant-temperature oven at 100℃ for 5 hours to cure, resulting in the main magnetic ring. The relative initial permeability of the main magnetic ring was tested to be 55,000, and the effective permeability at 100kHz was 25,000.

[0054] (2) A roll of nanocrystalline ribbon with a width of 50 mm and a thickness of 18 μm, the nominal composition of which is Fe bal. Cu1Nb3Si 15.5 B7 (at.%), after crystallization annealing at 560℃, is laminated with a 3μm thick pressure-sensitive double-sided adhesive. The tape coated with double-sided adhesive is then laminated in multiple layers to obtain a multi-layered nanocrystalline tape. This multi-layered tape undergoes magnetic crushing (molding crushing; by adjusting the mold and pressure, the size of the fragments can be controlled to 1mm, and the width of the cracks to 0.2μm) to reduce its permeability. The magnetically crushed tape is then die-cut with a flat die, and through simultaneous release film removal and waste removal stacking, a stacked strip magnetic assembly with a total thickness × length × width of 5mm × 15mm × 10mm is obtained. The resulting stacked strip magnetic assembly has a relative initial permeability of 1000, and its effective permeability at 100kHz is also 1000.

[0055] (3) Place the main magnetic ring obtained in step (1) into the matching plastic protective box, and then insert the two strip magnetic components obtained in step (2) evenly into the window of the main magnetic ring. The two ends of the magnetic components are in contact with the inner wall of the main magnetic ring to obtain a three-phase common mode inductor core with differential mode interference suppression function.

[0056] A schematic diagram of the structure of the inductor core obtained in this embodiment is shown below. Figure 3 As shown.

[0057] According to the test, the inductor core obtained in this embodiment has a common-mode inductance of 21μH and a differential-mode inductance of 0.33μH at a frequency of 100kHz. After applying a bias current of 10A, the differential-mode inductance decreases to 0.18μH.

[0058] The comparison between this embodiment and Embodiment 2 shows that the present invention can further adjust the differential mode inductance by adjusting the number and position of the magnetic components, and has the advantages of flexible structural design and performance adjustment.

[0059] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A common-mode inductor core with differential-mode interference suppression capability, characterized in that, It includes a main magnetic ring made of nanocrystalline ribbon and a magnetic component disposed within a window of the main magnetic ring; the magnetic permeability of the magnetic component is lower than that of the main magnetic ring, and both ends of the magnetic component are in contact with the main magnetic ring. The method for fabricating the common-mode inductor core includes the following steps: (1) The composition is Fe bal. M a Cu b M' c Si d B e X f Iron-based nanocrystalline ribbons are wound into closed magnetic circuit cores, and after heat treatment for crystallization annealing, they are impregnated and cured with epoxy resin to obtain the main magnetic ring; wherein M is Co and / or Ni, M' is at least one of Nb, V, Ta, and Mo, and X is at least one of common impurity elements such as C, O, Si, N, S, and P; a=0~30%, b=0.5~2%, c=2~7%, d=5~18%, e=5~10%, and f=0~0.5%; (2) The composition is Fe bal. Cu x Nb y Si z B n After heat treatment and crystallization annealing, iron-based nanocrystalline ribbons are laminated in multiple layers using pressure-sensitive double-sided adhesive. The resulting multilayer ribbons are then subjected to magnetic fragmentation treatment to reduce their magnetic permeability. The magnetically fragmented ribbons are then die-cut to form magnetic components; where x = 0.8~1.2%, y = 2~4%, z = 15~16%, and n = 6~8%. (3) Place the main magnetic ring obtained in step (1) into the matching plastic protective box, and then insert the magnetic component obtained in step (2) into the window of the main magnetic ring. The two ends of the magnetic component are in contact with the inner wall of the main magnetic ring to obtain a common mode inductor core with differential mode interference suppression function.

2. A common-mode inductor core with differential-mode interference suppression as described in claim 1, characterized in that, The main magnetic ring is a closed magnetic circuit that is ring-shaped, racetrack-shaped, rectangular, or elliptical.

3. A common-mode inductor core with differential-mode interference suppression as described in claim 1, characterized in that, In the composition of the iron-based nanocrystalline ribbon, a=0~12%, b=0.8~1.2%, c=2~4%, d=15~16%, e=6~8%, and f=0~0.2%.

4. A common-mode inductor core with differential-mode interference suppression as described in claim 1, characterized in that, The number of magnetic components is one or more; the shape of the magnetic components is a strip, a broken line, a wedge, a trapezoid, or an S-shape with a certain width.

5. A common-mode inductor core with differential-mode interference suppression as described in claim 1, characterized in that, The relative initial permeability of the main magnetic ring is 2 to 200,000, and its effective permeability at 100 kHz is 15,000 to 60,000; the relative initial permeability of the magnetic component is 100 to 30,000, and its effective permeability at 100 kHz is 100 to 30,000.

6. A method for preparing a common-mode inductor core with differential-mode interference suppression, characterized in that, The preparation steps include the following: (1) The composition is Fe bal. M a Cu b M' c Si d B e X f Iron-based nanocrystalline ribbons are wound into closed magnetic circuit cores, and after heat treatment for crystallization annealing, they are impregnated and cured with epoxy resin to obtain the main magnetic ring; wherein M is Co and / or Ni, M' is at least one of Nb, V, Ta, and Mo, and X is at least one of common impurity elements such as C, O, Si, N, S, and P; a=0~30%, b=0.5~2%, c=2~7%, d=5~18%, e=5~10%, and f=0~0.5%; (2) The composition is Fe bal. Cu x Nb y Si z B n After heat treatment and crystallization annealing, iron-based nanocrystalline ribbons are laminated in multiple layers using pressure-sensitive double-sided adhesive. The resulting multilayer ribbons are then subjected to magnetic fragmentation treatment to reduce their magnetic permeability. The magnetically fragmented ribbons are then die-cut to form magnetic components; where x = 0.8~1.2%, y = 2~4%, z = 15~16%, and n = 6~8%. (3) Place the main magnetic ring obtained in step (1) into the matching plastic protective box, and then insert the magnetic component obtained in step (2) into the window of the main magnetic ring. The two ends of the magnetic component are in contact with the inner wall of the main magnetic ring to obtain a common mode inductor core with differential mode interference suppression function.

7. The method for preparing a common-mode inductor core with differential-mode interference suppression according to claim 6, characterized in that, The width of the iron-based nanocrystalline ribbon in step (1) is 1~100mm and the thickness is 5~25μm.

8. The method for preparing a common-mode inductor core with differential-mode interference suppression according to claim 6, characterized in that, The temperature of the heat treatment crystallization annealing in steps (1) and (2) is 450~620℃.

9. The method for preparing a common-mode inductor core with differential-mode interference suppression according to claim 6, characterized in that, The epoxy resin solution mentioned in step (1) includes epoxy resin, low molecular weight polyamide curing agent and diluent.

10. The method for preparing a common-mode inductor core with differential-mode interference suppression according to claim 9, characterized in that, The epoxy resin is selected from type E epoxy resin, the low molecular weight polyamide curing agent is selected from 650 low molecular weight polyamide, and the diluent is at least one of anhydrous ethanol, ethyl acetate, and ethylene glycol.

11. The method for preparing a common-mode inductor core with differential-mode interference suppression according to claim 6, characterized in that, The impregnation curing mentioned in step (1) refers to immersing the epoxy resin in the solution for 10s to 5min under normal pressure or vacuum conditions, then taking it out and letting it drain naturally before curing it at 50 to 120℃ for 2 to 10h.

12. The method for preparing a common-mode inductor core with differential-mode interference suppression according to claim 6, characterized in that, The width of the iron-based nanocrystalline ribbon in step (2) is 10~100mm and the thickness is 5~25μm.

13. The method for preparing a common-mode inductor core with differential-mode interference suppression according to claim 6, characterized in that, The magnetic fragmentation treatment mentioned in step (2) refers to the use of transverse or longitudinal roller shearing, rolling with a round roller or flat plate with protrusions, or other methods that can make the nanocrystalline ribbon have uniform fragmentation gaps; the size of the fragmented pieces after the magnetic fragmentation treatment is 0.1~3mm; the width of the fragmentation gaps is 0.02~10μm.

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