High saturation assembled inductor and method for manufacturing the same

Abstract

The application relates to the technical field of electronic inductor devices and magnetic materials, in particular to a high-saturation assembled inductor and a preparation method thereof. The assembled inductor comprises a first magnet, a second magnet and windings. The first magnet is located at the geometric center of the second magnet and is a Fe-based amorphous laminated structure. The second magnet is formed by grading Fe-based alloy powder and alloy fine powder. The first magnet and the second magnet have a resin-filled isolation gap of 0.05-0.15 microns. Four groups of winding sections are uniformly distributed around the first magnet and make the magnetic lines intersect at the first magnet. The first magnet inhibits premature saturation of the intersection area through sheet thickness, sheet gap and mesoporous oxide filler. The second magnet controls Fe crystals through Si and P and fills the intergranular gap with alloy fine powder to improve the large-current inductance retention rate under the condition of low direct-current resistance, and is suitable for low-height high-saturation power inductor devices.

Description

[Technical Field] This invention relates to the field of electronic inductor devices and magnetic materials, and particularly to a high-saturation assembled inductor and its preparation method. [Background Technology] As the power of AI servers, high-performance computing devices, and high-power power modules continues to increase, the power input current increases significantly. Power inductors need to maintain a high inductance value under greater load current while simultaneously meeting the assembly requirements of low height, small size, low DC resistance, and low loss.

[0003] Existing powder alloy inductor materials typically rely on a single powder magnet or conventional alloy powder molding structure, making it difficult to simultaneously achieve optimal permeability, saturation flux density, and inductance retention under high current. When the number of windings is increased to improve the inductance, the DC resistance of the device rises accordingly, leading to increased heat generation and losses. Conversely, reducing the number of windings to control DC resistance and height can easily result in insufficient inductance at rated current.

[0004] Furthermore, in assembled inductors with multiple windings or multiple magnetic flux paths, the region where magnetic field lines intersect is usually the location with the highest local magnetic flux density. This region is prone to magnetic saturation before the main magnet, resulting in a rapid decrease in inductance under high current. Simply increasing the compaction density of the main powder or changing the conventional powder particle size is insufficient to effectively resolve the contradiction between premature saturation in the magnetic field line intersection region and insufficient filling density of the main magnet. [Summary of the Invention] To overcome the above problems, this invention proposes a high-saturation assembled inductor and its preparation method that can effectively solve the above problems.

[0006] The present invention provides a technical solution to solve the above-mentioned technical problems by providing a high-saturation assembled inductor, comprising a first magnet, a second magnet, and a winding. The first magnet is disposed at the geometric center of the second magnet and has a laminated structure. The second magnet is disposed around the first magnet, and an isolation gap of 0.05 μm to 0.15 μm is formed between the first magnet and the second magnet. The isolation gap is filled with silicone resin or silicone resin. The winding comprises four sets of winding segments uniformly distributed around the first magnet, and the magnetic lines of force generated by the four sets of winding segments converge at the first magnet. The first magnet is formed by stacking Fe-based non-flake materials, the composition of which includes 66.0 wt% to 81.5 wt% Fe, 10.0 wt% to 20.0 wt% Co, 4.0 wt% to 6.5 wt% P, 4.0 wt% to 6.5 wt% B, and 0.5 wt% to 1.0 wt% C, with the content of each element being based on the Fe content. The first element is formed by pressing a mixture of Fe-based alloy powder and fine alloy powder. The Fe-based alloy powder contains 88.5 wt% to 92.5 wt% Fe, 2.5 wt% to 4.0 wt% Si, 4.5 wt% to 6.5 wt% P, and 0.5 wt% to 1.0 wt% Cr. The content of each element is based on the total weight of the Fe-based alloy powder, and the total weight of each element is 100 wt%.

[0007] This invention improves inductance retention under high current by setting a stacked Fe-based amorphous first magnet with a layered structure in the intersection region of the magnetic field lines of four windings, and setting a second magnet composed of Fe-based alloy powder and fine alloy powder around its outer periphery. This allows the magnetic field line intersection region and the main magnetic flux region to be borne by different magnetic materials. Fe and Co are used to provide higher saturation magnetic flux density, P and B are beneficial for forming a stable amorphous structure, and C, as a trace amorphous forming element, is used to improve the stability of the sheet structure and the consistency of magnetic properties. Si and P are used to control the size and distribution of Fe crystals, and Cr is used to improve the surface stability and oxidation resistance of the powder. The fine alloy powder is selected from one or more of FeSi powder, FeSiCr powder, and FeSiAl powder. The fine powder is graded to fill the gaps between the Fe-based alloy powders, thereby improving the magnet's density and reducing DC resistance.

[0008] Preferably, the volume ratio of the first magnet to the second magnet is 1:10 to 1:4. This volume ratio allows the first magnet to concentrate on the anti-saturation function in the region where magnetic field lines intersect, while ensuring that the second magnet has sufficient volume to form the main magnetic flux path.

[0009] Preferably, the thickness of the Fe-based non-flake material is 15 μm to 50 μm, and a sheet gap of 0.05 μm to 0.2 μm is formed between two adjacent layers of the Fe-based non-flake material.

[0010] Preferably, the gaps in the sheet are provided with mesoporous oxide and mixed resin, wherein the mesoporous oxide accounts for 20% to 50% of the weight of the filler in the gaps in the sheet, and the remainder is the mixed resin.

[0011] Preferably, the mesoporous oxide is mesoporous alumina and / or mesoporous silica; the mixed resin is a resin system composed of silicone resin or silicone resin and urea-formaldehyde resin, wherein the silicone resin or silicone resin accounts for 50% to 80% of the weight of the mixed resin.

[0012] Preferably, the Fe-based alloy powder has a particle size of 8 μm to 12 μm, and the surface of the Fe-based alloy powder is coated with an oxide layer, which is a silicon oxide layer and / or an aluminum oxide layer, and the thickness of the oxide layer is 5 nm to 15 nm.

[0013] Preferably, the Fe-based alloy powder accounts for 70% to 85% of the weight of the mixed powder.

[0014] Preferably, the alloy fine powder is selected from one or more of FeSi powder, FeSiCr powder, and FeSiAl powder, and the particle size of the alloy fine powder is 0.5μm to 3μm.

[0015] Preferably, the surface of the alloy fine powder is coated with an oxide layer, which is a silicon oxide layer and / or an aluminum oxide layer, and the thickness of the oxide layer is 5 nm to 15 nm; the alloy fine powder accounts for 15% to 30% of the weight of the mixed powder.

[0016] Preferably, the alloy powder in the second magnet is distributed within the interparticle gaps between the Fe-based alloy powder to increase the filling density of the second magnet and reduce the DC resistance of the assembled inductor.

[0017] Preferably, the first magnet forms an anti-saturation magnetic flux channel in the region where the magnetic lines of force of the four sets of winding segments intersect, the second magnet forms a powder magnetic flux body on the outer periphery of the first magnet, and the isolation gap and the sheet gap together constitute a magnetic flux buffer structure.

[0018] Preferably, when the dimensions of the assembled inductor are 6mm×5mm×3mm and the number of turns of the winding is 0.5 turns, the inductance value of the assembled inductor is not less than 70nH under 1MHz and 0.1A conditions, the inductance value is not less than 49nH under 1MHz and 50A conditions, the inductance retention rate is not less than 68.0%, and the DC resistance is not higher than 0.16mΩ.

[0019] This invention also provides a method for preparing a high-saturation assembled inductor, comprising the following steps: Step S1: Prepare the Fe-based non-crystalline material and stack the Fe-based non-crystalline material to form the first magnet; Step S2: Prepare the Fe-based alloy powder and the alloy fine powder, and form an oxide layer on the surface of the Fe-based alloy powder and the alloy fine powder respectively; Step S3: Mix the Fe-based alloy powder with the alloy fine powder to form the mixed powder; Step S4: Place the first magnet at the geometric center of the molding die, fill the outer periphery of the first magnet with the mixed powder and press it to form the second magnet surrounding the first magnet; Step S5: Form the isolation gap between the first magnet and the second magnet, and fill the isolation gap with silicone resin or silicone resin. Step S6: Arrange the four sets of winding segments evenly around the first magnet so that the magnetic lines of force formed by the four sets of winding segments when they are working converge at the first magnet. Step S7 involves curing, shaping, and end treatment to obtain the high-saturation assembled inductor.

[0020] Preferably, when preparing the first magnet, a gap-filling material composed of mesoporous oxide and mixed resin is coated between two adjacent Fe-based non-sheet materials, and the gap between the sheets is controlled to be 0.05 μm to 0.2 μm by lamination.

[0021] Preferably, in preparing the mixed powder, the Fe-based alloy powder with a particle size of 8 μm to 12 μm is mixed with the alloy fine powder with a particle size of 0.5 μm to 3 μm in a graded manner, so that the alloy fine powder fills the gaps between the Fe-based alloy powder, and then the mixed powder is filled into the molding die and pressed to form the second magnet.

[0022] Compared with the prior art, the high-saturation assembled inductor and its preparation method of the present invention have the following beneficial effects: 1. The present invention arranges the Fe-based amorphous first magnet with a laminated structure at the intersection of the magnetic field lines of the four windings, so that the most easily saturated local area is borne by the highly saturated amorphous laminate, which can suppress premature saturation in the magnetic field line intersection area and improve the inductance retention rate under high current.

[0023] 2. By controlling the thickness of the first magnet sheet, the sheet gap, and the composition of the sheet gap filler, the present invention forms a controllable micro-gap and an insulating isolation structure inside the stacked magnet, which is beneficial for adjusting saturation performance and reducing high-frequency loss.

[0024] 3. The second magnet of the present invention adopts a graded composite structure of Fe-based alloy powder and fine alloy powder. The Fe-based alloy powder improves the saturation performance by controlling the size and distribution of Fe crystals through Si and P. The fine alloy powder fills the gaps between coarse powder particles to increase the filling density, thereby increasing the inductance under low DC resistance conditions.

[0025] 4. The present invention sets a micron-level isolation gap between the first magnet and the second magnet and fills it with silicone resin or silicone resin, so that a magnetic flux buffer and structural bonding region is formed between the first magnet and the second magnet, which helps to alleviate the abrupt change in magnetic properties between different magnetic materials and improve device consistency.

[0026] 5. This invention establishes an inseparable synergistic relationship between the first magnet, the second magnet, the winding distribution, the sheet gap, and the powder gradation. It can still meet the requirements of high inductance and high saturation while reducing the number of winding coils, and is suitable for low-profile, high-current-density power devices. [Attached Image Description] Figure 1 This is a first cross-sectional view of the high-saturation assembled inductor of the present invention; Figure 2 This is a second cross-sectional view of the high-saturation assembled inductor of the present invention; Figure 3 This is a third cross-sectional view of the high-saturation assembled inductor of the present invention.

Detailed Implementation Methods

[0029] It should be noted that in the embodiments of the present invention, all directional indications (such as up, down, left, right, front, back, etc.) are limited to relative positions on the specified view, rather than absolute positions.

[0030] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0031] Please see Figures 1 to 3The high-saturation assembled inductor of the present invention comprises a first magnet 1, a second magnet 2, and a winding 3. The first magnet 1 is located at the geometric center of the second magnet 2, and there is a gap of 0.05~0.15µm between the first magnet 1 and the second magnet 2, which is filled with silicone resin or silicone ketone resin. The volume ratio of the first magnet 1 to the second magnet 2 is 1:10 to 1:4. The winding 3 is uniformly distributed around the first magnet 1, and its magnetic lines of force intersect with the first magnet 1. The first magnet 1 has a laminated structure.

[0032] The first magnet 1 is composed of Fe-based amorphous material with the following composition: 66.0wt%~81.5wt% Fe, 10.0wt%~20.0wt% Co, 4.0wt%~6.5wt% P, 4.0wt%~6.5wt% B, and 0.5wt%~1.0wt% C. The thickness of the non-sheet material is 15~50µm, and the inter-sheet gap is 0.05~0.2µm. The inter-sheet gap is composed of mesoporous oxide, such as mesoporous alumina or mesoporous silicon oxide, etc., with the mesoporous oxide accounting for 20%~50% of the weight ratio of the inter-sheet gap. The remainder is silicone resin or a mixture of silicone resin and urea-formaldehyde resin, with silicone resin accounting for 50%~80% of the weight ratio of the mixed resin.

[0033] The second magnet 2 is composed of an Fe-based alloy material, specifically a composite material of powder and alloy powder, comprising 88.5wt%~92.5wt% Fe, 2.5wt%~4.0wt% Si, 4.5wt%~6.5wt% P, and 0.5wt%~1.0wt% Cr. The Fe-based alloy powder has a particle size of 8~12 μm, and its surface is coated with an oxide layer, such as silicon oxide or aluminum oxide, with a thickness of 5~15 nm. The Fe-based alloy powder accounts for 70%~85% of the weight of the mixed powder. The alloy powder, such as FeSi, FeSiCr, and FeSiAl, has a particle size of 0.5~3 μm, and its surface is coated with an oxide layer, such as silicon oxide or aluminum oxide, with a thickness of 5~15 nm. The alloy powder accounts for 15%~30% of the weight of the mixed powder.

[0034] The sample size was 6mm*5mm*3mm, with 0.5 turns in the winding. The inductance L value and the inductance value at 50A were tested using a WK6500B at 1MHz and 1V. The inductance loss was tested using a SY8218.

[0035] The present invention will be further described below with reference to specific embodiments.

[0036] Example 1: A high-saturation assembled inductor comprises a first magnet 1, a second magnet 2, and a winding 3. The first magnet 1 is located at the geometric center of the second magnet 2, and there is a 0.15 μm gap between the first magnet 1 and the second magnet 2, which is filled with silicone resin. The volume ratio of the first magnet 1 to the second magnet 2 is 1:10. The winding 3 is uniformly distributed around the first magnet 1, and its magnetic field lines intersect with the first magnet 1. The first magnet 1 has a laminated structure.

[0037] The first magnet 1 is composed of Fe-based amorphous material with the following composition: 81.5 wt% Fe, 10.0 wt% Co, 4.0 wt% P, 4.0 wt% B, and 0.5 wt% C. The thickness of the amorphous material is 15 μm, and the gap between the sheets is 0.05 μm. The gap between the sheets is composed of mesoporous silicon oxide, which accounts for 20% of the weight ratio of the gap between the sheets. The remainder is a mixture of silicone resin and urea-formaldehyde resin, with silicone resin accounting for 50% of the weight ratio of the mixture.

[0038] The second magnet 2 is composed of an Fe-based alloy material, specifically a composite material of powder and alloy powder, consisting of 92.5 wt% Fe, 2.5 wt% Si, 4.5 wt% P, and 0.5 wt% Cr. The Fe-based alloy powder has a particle size of 8 μm, and its surface is coated with a 5 nm thick layer of alumina. The Fe-based alloy powder accounts for 70% of the weight of the mixed powder. The alloy powder, of type FeSiCr, has a particle size of 0.5 μm and its surface is coated with a 5 nm thick layer of alumina. This alloy powder accounts for 15% of the weight of the mixed powder.

[0039] The sample size was 6mm*5mm*3mm, with 0.5 turns in the winding. The inductance L value and the inductance value at 50A were tested using a WK6500B at 1MHz and 1V. The inductance loss was tested using a SY8218.

[0040] Example 2: A high-saturation assembled inductor comprises a first magnet 1, a second magnet 2, and a winding 3. The first magnet 1 is located at the geometric center of the second magnet 2, and a 0.05 μm gap exists between the first magnet 1 and the second magnet 2, filled with silicone resin. The volume ratio of the first magnet 1 to the second magnet 2 is 1:4. The winding 3 is uniformly distributed around the first magnet 1, and its magnetic field lines intersect with the first magnet 1. The first magnet 1 has a laminated structure.

[0041] The first magnet 1 is composed of Fe-based amorphous material with the following composition: 66.0 wt% Fe, 20.0 wt% Co, 6.5 wt% P, 6.5 wt% B, and 1.0 wt% C. The thickness of the amorphous material is 50 μm, and the gap between the sheets is 0.2 μm. The gap between the sheets is composed of mesoporous alumina, with the mesoporous oxide accounting for 50% of the weight ratio of the gap between the sheets. The remainder is a mixture of silicone resin and urea-formaldehyde resin, with silicone resin accounting for 80% of the weight ratio of the mixture.

[0042] The second magnet 2 is composed of an Fe-based alloy material, specifically a composite material of powder and alloy powder, consisting of 88.5 wt% Fe, 4.0 wt% Si, 6.5 wt% P, and 1.0 wt% Cr. The Fe-based alloy powder has a particle size of 12 μm and is coated with a 15 nm thick layer of alumina. The Fe-based alloy powder accounts for 85% of the weight of the mixed powder. The alloy powder is FeSi, with a particle size of 3 μm and a 15 nm thick layer of silicon oxide. This alloy powder accounts for 30% of the weight of the mixed powder.

[0043] The sample size was 6mm*5mm*3mm, with 0.5 turns in the winding. The inductance L value and the inductance value at 50A were tested using a WK6500B at 1MHz and 1V. The inductance loss was tested using a SY8218.

[0044] Example 3: A high-saturation assembled inductor comprises a first magnet 1, a second magnet 2, and a winding 3. The first magnet 1 is located at the geometric center of the second magnet 2, and a 0.10 μm gap exists between the first magnet 1 and the second magnet 2, filled with silicone resin. The volume ratio of the first magnet 1 to the second magnet 2 is 1:6. The winding 3 is uniformly distributed around the first magnet 1, and its magnetic field lines intersect with the first magnet 1. The first magnet 1 has a laminated structure.

[0045] The first magnet 1 is composed of Fe-based amorphous material with the following composition: 73.0 wt% Fe, 15.0 wt% Co, 5.5 wt% P, 5.8 wt% B, and 0.7 wt% C. The thickness of the amorphous material is 30 μm, and the gap between the sheets is 0.12 μm. The gap between the sheets is composed of mesoporous alumina, which accounts for 40% of the weight of the gap between the sheets. The remainder is a mixture of silicone resin and urea-formaldehyde resin, with silicone resin accounting for 70% of the weight of the mixture.

[0046] The second magnet 2 is composed of an Fe-based alloy material, specifically a composite material of powder and alloy powder, consisting of 90.3 wt% Fe, 3.5 wt% Si, 5.5 wt% P, and 0.7 wt% Cr. The Fe-based alloy powder has a particle size of 10 μm, and its surface is coated with a 9 nm thick layer of alumina. The Fe-based alloy powder accounts for 78% of the weight of the mixed powder. The alloy powder is FeSiAl, with a particle size of 1.8 μm, and its surface is coated with a 10 nm thick layer of silicon oxide. This alloy powder accounts for 21% of the weight of the mixed powder.

[0047] The sample size was 6mm*5mm*3mm, with 0.5 turns in the winding. The inductance L value and the inductance value at 50A were tested using a WK6500B at 1MHz and 1V. The inductance loss was tested using a SY8218.

[0048] Comparative Example 1: A high-saturation assembled inductor comprises a first magnet 1, a second magnet 2, and a winding 3. The first magnet 1 is located at the geometric center of the second magnet 2, and there is a 0.15 μm gap between the first magnet 1 and the second magnet 2, which is filled with silicone resin. The volume ratio of the first magnet 1 to the second magnet 2 is 1:10. The winding 3 is uniformly distributed around the first magnet 1, and its magnetic field lines intersect with the first magnet 1. The first magnet 1 has a laminated structure.

[0049] The first magnet 1 is composed of Fe-based amorphous material with the following composition: 81.5 wt% Fe, 10.0 wt% Co, 4.0 wt% P, 4.0 wt% B, and 0.5 wt% C. The thickness of the amorphous material is 15 μm, and the gap between the sheets is 0.05 μm. The gap between the sheets is composed of mesoporous silicon oxide, which accounts for 20% of the weight of the gap between the sheets. The remainder is a mixture of silicone resin and urea-formaldehyde resin, with silicone resin accounting for 50% of the weight of the mixture. The second magnet 2 is composed of the same material and laminated structure as the first magnet 1.

[0050] The sample size was 6mm*5mm*3mm, with 0.5 turns in the winding. The inductance L value and the inductance value at 50A were tested using a WK6500B at 1MHz and 1V. The inductance loss was tested using a SY8218.

[0051] Comparative Example 2: A high-saturation assembled inductor comprises a first magnet 1, a second magnet 2, and a winding 3. The first magnet 1 is located at the geometric center of the second magnet 2, and there is a 0.15 μm gap between the first magnet 1 and the second magnet 2, which is filled with silicone resin. The volume ratio of the first magnet 1 to the second magnet 2 is 1:10. The winding 3 is uniformly distributed around the first magnet 1, and its magnetic field lines intersect with those of the first magnet 1.

[0052] The first magnet 1 and the second magnet 2 are composed of an Fe-based alloy material, specifically a composite material consisting of 92.5 wt% Fe, 2.5 wt% Si, 4.5 wt% P, and 0.5 wt% Cr powder and alloy powder. The Fe-based alloy powder has a particle size of 8 μm, and its surface is coated with a 5 nm thick layer of alumina. The Fe-based alloy powder accounts for 70% of the weight of the mixed powder. The alloy powder is FeSiCr, with a particle size of 0.5 μm, and its surface is coated with a 5 nm thick layer of alumina. The alloy powder accounts for 15% of the weight of the mixed powder.

[0053] The sample size was 6mm*5mm*3mm, with 0.5 turns in the winding. The inductance L value and the inductance value at 50A were tested using a WK6500B at 1MHz and 1V. The inductance loss was tested using a SY8218.

[0054] Comparative Example 3: A high-saturation assembled inductor comprises a first magnet 1, a second magnet 2, and a winding 3. The first magnet 1 is located at the geometric center of the second magnet 2, and there is a 0.15 μm gap between the first magnet 1 and the second magnet 2, which is filled with silicone resin. The volume ratio of the first magnet 1 to the second magnet 2 is 1:10. The winding 3 is uniformly distributed around the first magnet 1, and its magnetic field lines intersect with the first magnet 1. The first magnet 1 has a laminated structure.

[0055] The first magnet 1 is composed of Fe-based amorphous material with a composition of 81.5 wt% Fe, 10.0 wt% Co, 4.0 wt% P, 4.0 wt% B, and 0.5 wt% C. The thickness of the amorphous material is 15 μm, and there are no interstitial fillers between the sheets. The second magnet 2 is composed of Fe-based alloy material, a composite material of powder and alloy powder with a composition of 92.5 wt% Fe, 2.5 wt% Si, 4.5 wt% P, and 0.5 wt% Cr. The particle size of the Fe-based alloy powder is 8 μm, and the surface of the Fe-based alloy is coated with a layer of alumina with a thickness of 5 nm. The Fe-based alloy powder accounts for 70% of the weight of the mixed powder. The alloy powder is FeSiCr, with a particle size of 0.5 μm, and the surface of the alloy powder is coated with a layer of alumina with a thickness of 5 nm. The alloy powder accounts for 15% of the weight of the mixed powder.

[0056] The sample size was 6mm*5mm*3mm, with 0.5 turns in the winding. The inductance L value and the inductance value at 50A were tested using a WK6500B at 1MHz and 1V. The inductance loss was tested using a SY8218.

[0057] Comparative Example 4: A high-saturation assembled inductor comprises a first magnet 1, a second magnet 2, and a winding 3. The first magnet 1 is located at the geometric center of the second magnet 2, and there is a 0.15 μm gap between the first magnet 1 and the second magnet 2, which is filled with silicone resin. The volume ratio of the first magnet 1 to the second magnet 2 is 1:10. The winding 3 is uniformly distributed around the first magnet 1, and its magnetic field lines intersect with the first magnet 1. The first magnet 1 has a laminated structure.

[0058] The first magnet 1 is composed of Fe-based amorphous material with the following composition: 81.5 wt% Fe, 10.0 wt% Co, 4.0 wt% P, 4.0 wt% B, and 0.5 wt% C. The thickness of the amorphous material is 15 μm, and the inter-sheet spacing is 0.05 μm. The inter-sheet spacing is composed of mesoporous silicon oxide, which accounts for 20% of the weight percentage of the inter-sheet spacing. The remainder is a mixture of silicone resin and urea-formaldehyde resin, with silicone resin accounting for 50% of the weight percentage of the mixture. The second magnet 2 is composed of Fe-based alloy material with the following composition: 92.5 wt% Fe, 2.5 wt% Si, 4.5 wt% P, and 0.5 wt% Cr powder. The particle size of the Fe-based alloy powder is 8 μm, and the surface of the Fe-based alloy is coated with a layer of alumina with a thickness of 5 nm. The Fe-based alloy powder accounts for 100% of the weight percentage of the mixed powder.

[0059] The sample size was 6mm*5mm*3mm, with 0.5 turns in the winding. The inductance L value and the inductance value at 50A were tested using a WK6500B at 1MHz and 1V. The inductance loss was tested using a SY8218.

[0060] Comparative Example 5: A high-saturation assembled inductor comprises a first magnet 1, a second magnet 2, and a winding 3. The first magnet 1 is located at the geometric center of the second magnet 2, and there is a 0.15 μm gap between the first magnet 1 and the second magnet 2, which is filled with silicone resin. The volume ratio of the first magnet 1 to the second magnet 2 is 1:10. The winding 3 is uniformly distributed around the first magnet 1, and its magnetic field lines intersect with the first magnet 1. The first magnet 1 has a laminated structure.

[0061] The first magnet 1 is composed of Fe-based amorphous material with the following composition: 81.5 wt% Fe, 10.0 wt% Co, 4.0 wt% P, 4.0 wt% B, and 0.5 wt% C. The thickness of the amorphous material is 15 μm, and the gap between the sheets is 0.05 μm. The gap between the sheets is composed of mesoporous silicon oxide, which accounts for 20% of the weight ratio of the gap between the sheets. The remainder is a mixture of silicone resin and urea-formaldehyde resin, with silicone resin accounting for 50% of the weight ratio of the mixture. The second magnet 2 is composed of Fe-based alloy material, consisting of a composite material of powder and alloy powder with the following composition: 92.5 wt% Fe, 2.5 wt% Si, 4.5 wt% P, and 0.5 wt% Cr. The particle size of the Fe-based alloy powder is 8 μm, and the surface of the Fe-based alloy is coated with a layer of alumina with a thickness of 5 nm. The Fe-based alloy powder accounts for 70% of the weight ratio of the mixed powder. The alloy powder is FeSiCr, the particle size of the alloy powder is 0.5 μm, and the alloy powder accounts for 15% of the weight of the mixed powder.

[0062] The sample size was 6mm*5mm*3mm, with 0.5 turns in the winding. The inductance L value and the inductance value at 50A were tested using a WK6500B at 1MHz and 1V. The inductance loss was tested using a SY8218.

[0063] Table 1. Performance Comparison of Examples and Comparative Examples

[0064] As shown in Table 1, under similar DCR conditions, the inductance values ​​of Examples 1 to 3 reached 49nH, 51nH, and 50nH respectively at 1MHz and 50A, with inductance retention rates of 70.0%, 68.0%, and 70.4%, respectively, significantly higher than those of Comparative Examples 1 to 5. This indicates that placing the Fe-based amorphous first magnet with a stacked structure in the magnetic field line intersection region and graded Fe-based alloy powder with fine alloy powder to form the second magnet can effectively improve the high-current saturation performance of the assembled inductor.

[0065] Comparative Example 1 uses the same laminated structure as the first magnet 1 for the second magnet 2. Its 50A inductance and inductance retention rate are lower than those of the embodiment, indicating that the powder-graded structure in the main magnetic flux region is necessary to maintain overall inductance performance. Comparative Example 2 uses powder structures for both the first magnet 1 and the second magnet 2. Its high-current inductance and inductance retention rate decrease significantly, indicating that the Fe-based amorphous laminated structure in the magnetic flux intersection region plays a crucial role in suppressing premature local saturation.

[0066] Comparative Example 3, which did not have interlayer filler between the Fe-based non-flake materials, showed increased inductance loss and decreased high-current inductance, indicating that the combination of interlayer and mesopore oxides with the mixed resin helps improve the magnetic performance stability of the stacked magnets. Comparative Example 4 did not add alloy powder, and Comparative Example 5 did not have an oxide layer on the surface of the alloy powder; their performance was lower than that of the examples, indicating that powder gradation and the oxide layer on the powder surface have a synergistic contribution to reducing losses and improving inductance retention.

[0067] In summary, this invention does not simply replace magnetic materials. Instead, it achieves high saturation, low DCR, and low height through the combined effects of the Fe-based amorphous laminated structure of the first magnet 1, the Fe-based alloy powder and fine alloy powder gradation structure of the second magnet 2, the isolation gap between the first magnet 1 and the second magnet 2, and the four sets of uniformly distributed magnetic flux intersection structures of the winding 3. Comparing the embodiments and the comparative examples, it can be seen that under similar DCR conditions, the inductance of the embodiment is higher than that of the comparative example at a loaded current of 40A. This indicates that the control of the component composition and the assembly structure design are crucial for achieving high saturation while meeting the inductance requirements.

[0068] Compared with existing technologies, the high-saturation assembled inductor and its preparation method of the present invention, through material ratio and device structure design, avoids premature saturation by using non-crystalline materials with a stacked structure at the intersection of four sets of coils, thereby increasing the inductance value under high current and reducing the number of winding coils. At the same time, the spacing between the sheets is controlled to adjust the saturation performance, and the saturation characteristics are further improved by the powder structure of the main body. The powder material controls the size and distribution of Fe crystals through Si and P to improve the saturation performance of the material and ensure that the main body does not saturate prematurely. At the same time, the graded fine powder fills the gaps to further increase the inductance and reduce the DCR, ensuring that the inductance value meets the requirements at a lower DCR and that the saturation capability is superior, thereby meeting the application requirements for power devices with low device height and high saturation.

[0069] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any modifications, equivalent substitutions and improvements made within the concept of the present invention should be included within the patent protection scope of the present invention.

Claims

1. A high saturation assembled inductance characterized in that, It includes a first magnet, a second magnet, and a winding, wherein the first magnet is disposed at the geometric center of the second magnet, and the first magnet has a laminated structure; The second magnet is disposed around the first magnet, and an isolation gap of 0.05 μm to 0.15 μm is formed between the first magnet and the second magnet, the isolation gap being filled with silicone resin or silicone resin; The winding includes four sets of winding segments evenly distributed around the first magnet, and the magnetic lines of force generated by the four sets of winding segments converge at the first magnet. The first magnet is formed by stacking Fe-based non-crystalline materials. The Fe-based non-crystalline materials consist of 66.0 wt% to 81.5 wt% Fe, 10.0 wt% to 20.0 wt% Co, 4.0 wt% to 6.5 wt% P, 4.0 wt% to 6.5 wt% B, and 0.5 wt% to 1.0 wt% C, with the content of each element based on the total weight of the Fe-based non-crystalline materials, and the total amount of each element being 100 wt%. The second magnet is formed by pressing a mixture of Fe-based alloy powder and fine alloy powder. The Fe-based alloy powder comprises 88.5 wt% to 92.5 wt% Fe, 2.5 wt% to 4.0 wt% Si, 4.5 wt% to 6.5 wt% P, and 0.5 wt% to 1.0 wt% Cr. The content of each element is based on the total weight of the Fe-based alloy powder, and the total amount of each element is 100 wt%.

2. The high saturation assembled inductance of claim 1, wherein: The volume ratio of the first magnet to the second magnet is 1:10 to 1:

4.

3. The high saturation assembled inductance of claim 1, wherein: The thickness of the Fe-based non-flake material is 15 μm to 50 μm, and a sheet gap of 0.05 μm to 0.2 μm is formed between two adjacent layers of the Fe-based non-flake material.

4. The high saturation assembled inductance of claim 3, wherein: The sheet gaps are provided with mesoporous oxide and mixed resin, wherein the mesoporous oxide accounts for 20% to 50% of the weight of the filler in the sheet gaps, and the remainder is the mixed resin.

5. The high saturation assembled inductance of claim 4, wherein: The mesoporous oxide is mesoporous alumina and / or mesoporous silica; the mixed resin is a resin system composed of silicone resin or silicone resin and urea-formaldehyde resin, wherein the silicone resin or silicone resin accounts for 50% to 80% of the weight of the mixed resin.

6. The high saturation assembled inductance of claim 1, wherein: The Fe-based alloy powder has a particle size of 8 μm to 12 μm, and the surface of the Fe-based alloy powder is coated with an oxide layer, which is a silicon oxide layer and / or an aluminum oxide layer, and the thickness of the oxide layer is 5 nm to 15 nm.

7. The high saturation assembled inductance of claim 6, wherein: The Fe-based alloy powder accounts for 70% to 85% of the weight of the mixed powder.

8. The high saturation assembled inductance of claim 1, wherein: The alloy fine powder is selected from one or more of FeSi powder, FeSiCr powder, and FeSiAl powder, and the particle size of the alloy fine powder is 0.5μm to 3μm.

9. The high saturation assembled inductance of claim 8, wherein: The surface of the alloy fine powder is coated with an oxide layer, which is a silicon oxide layer and / or an aluminum oxide layer, and the thickness of the oxide layer is 5 nm to 15 nm; the alloy fine powder accounts for 15% to 30% of the weight of the mixed powder.

10. A method for preparing a high-saturation assembled inductor as described in any one of claims 1 to 9, characterized in that, Includes the following steps: Step S1: Prepare the Fe-based non-crystalline material and stack the Fe-based non-crystalline material to form the first magnet; Step S2: Prepare the Fe-based alloy powder and the alloy fine powder, and form an oxide layer on the surface of the Fe-based alloy powder and the alloy fine powder respectively; Step S3: Mix the Fe-based alloy powder with the alloy fine powder to form the mixed powder; Step S4: Place the first magnet at the geometric center of the molding die, fill the outer periphery of the first magnet with the mixed powder and press it to form the second magnet surrounding the first magnet; Step S5: Form the isolation gap between the first magnet and the second magnet, and fill the isolation gap with silicone resin or silicone resin. Step S6: Arrange the four sets of winding segments evenly around the first magnet so that the magnetic lines of force formed by the four sets of winding segments when they are working converge at the first magnet. Step S7 involves curing, shaping, and end treatment to obtain the high-saturation assembled inductor.

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