A mixture for forming a multilayer inductor and a method of manufacturing the same

Abstract

The present application discloses a mixture for forming a multilayer inductor and a manufacturing method thereof, the mixture comprising a first magnetic powder, a second magnetic powder and a glass material, wherein D50 of the first magnetic powder is greater than D50 of the second magnetic powder, and each of the first magnetic powder and the second magnetic powder comprises an amorphous magnetic powder or a nanocrystalline magnetic powder, and the softening point temperature of the glass material is 300-430 DEG C.

Description

Technical Field

[0001] This invention relates to a mixture of ultra-low temperature sintered amorphous or nanocrystalline magnetic powders for forming multilayer inductors and a method thereof. Background Technology

[0002] In recent years, electronic products such as mobile devices have become increasingly thinner and more feature-rich. Therefore, it is necessary to generate different voltages from the mobile device's battery to apply different voltages to different components, such as the LCD screen or wireless module within the mobile device. Multilayer inductors can be used in DC-DC converters, with design goals including reducing DC resistance (DCR) and improving power conversion efficiency.

[0003] Traditional iron alloy multilayer power inductors have moderate permeability but high iron loss, which reduces the conversion efficiency of conversion circuits or DC-DC converters.

[0004] Traditional multilayer power inductors use atomized silver as the internal circuit for sintering, and the sintering temperature needs to reach above 700℃ to achieve higher density and lower resistivity.

[0005] Accordingly, the present invention proposes a better method for designing multilayer inductors to overcome the above-mentioned problems. Summary of the Invention

[0006] One object of the present invention is to provide a mixture for forming multilayer inductors, wherein the mixture of the present invention can be formed at a lower temperature compared with conventional methods, wherein the mixture comprises amorphous or nanocrystalline magnetic powder with low iron loss to improve the conversion efficiency of the magnetic powder.

[0007] One object of the present invention is to provide a mixture for forming a multilayer inductor that can be sintered at a temperature not exceeding 470°C.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] The present invention provides a mixture for forming a multilayer inductor, the mixture comprising: a first magnetic powder, a second magnetic powder, and a glass material, wherein the D50 of the first magnetic powder is greater than the D50 of the second magnetic powder, and each of the first magnetic powder and the second magnetic powder comprises an amorphous magnetic powder or a nanocrystalline magnetic powder.

[0010] In one embodiment, the softening point temperature of the glass material is 300°C to 430°C.

[0011] In one embodiment, the first magnetic powder comprises Fe, Cr, Si, B, and C.

[0012] In one embodiment, the second magnetic powder comprises Fe, Cr, Si, B, and C.

[0013] In one embodiment, the D50 of the second magnetic powder is 1 to 2 μm.

[0014] In one embodiment, the glass material comprises glass powder, and the D50 of the glass powder is not greater than 1 μm.

[0015] In one embodiment, the D50 of the first magnetic powder is at least 7 times that of the second magnetic powder.

[0016] In one embodiment, the glass material comprises Bi, Zn, and B.

[0017] In one embodiment, the volume of the second magnetic powder accounts for 20-40% of the total volume of the mixture.

[0018] In one embodiment, the glass material covers the outer surface of each of the plurality of particles of the first magnetic powder, and the thickness of the glass material is not greater than 50 nm.

[0019] In one embodiment, an oxide layer covers the outer surface of each of the plurality of particles of the second magnetic powder, and the thickness of the oxide layer is not greater than 10 nm.

[0020] In one embodiment, the mixture is sintered in air with an oxygen content greater than 20% and a temperature not greater than 470°C to form a magnetic sheet.

[0021] In one embodiment, an oxide layer is coated on the surface of the second powder, wherein the thickness of the oxide layer is no greater than 10 nm.

[0022] The present invention also provides a mixture for forming a multilayer inductor, the mixture comprising: a first magnetic powder and a first insulating material, wherein the first magnetic powder comprises an amorphous magnetic powder or a nanocrystalline magnetic powder, the first insulating material comprises a first glass material having a softening point temperature in the range of 300°C to 430°C, wherein the first insulating material is coated on the outer surface of each of a plurality of particles in the first magnetic powder to make each of the plurality of particles of the first magnetic powder insulating.

[0023] In one embodiment, the mixture further includes a second insulating material filling the spaces between multiple particles of the first magnetic powder coated with the first insulating material, wherein the second insulating material comprises a second glass material having a softening point in the range of 300°C to 430°C.

[0024] In one embodiment, the thickness of the first insulating material on the outer surface of each of the plurality of particles coated in the first magnetic powder is in the range of 20 to 800 nm.

[0025] In one embodiment, the first insulating material comprises at least one of the following: SnO-P2O5, V2O5-TeO2, Bi2O3-B2O3, and ZnO.

[0026] In one embodiment, the weight of the first glass material is no more than 4% of the total weight of the first magnetic powder and the first glass material.

[0027] In one embodiment, the mixture further includes a second magnetic powder, the second glass material filling the space between the particles of the second magnetic powder and the particles of the first magnetic powder.

[0028] In one embodiment, the first insulating material comprises glass powder, wherein the D50 of the glass powder is not greater than 1 μm.

[0029] In one embodiment, the weight of the second glass material is no more than 8% of the total weight of the magnetic material.

[0030] In one embodiment, the thickness of the first glass material on the outer surface of each of the plurality of particles coated with the first magnetic powder is no greater than 50 nm.

[0031] The present invention also provides a method for preparing a mixture for forming a multilayer inductor, the method comprising the following steps:

[0032] A first magnetic powder is provided, wherein the first magnetic powder comprises an amorphous magnetic powder or a nanocrystalline magnetic powder; and

[0033] A first insulating material is coated on the outer surface of each of the plurality of particles of the first magnetic powder to make each of the plurality of particles of the first magnetic powder insulating, wherein the first insulating material comprises a first glass material having a softening point temperature in the range of 300°C to 430°C.

[0034] In one embodiment, the method further includes a filling step of filling a second magnetic powder and a second insulating material into the spaces between a plurality of particles of the first magnetic powder coated with the first glass material, wherein the second insulating material includes a second glass material, the D50 of the first magnetic powder is greater than the D50 of the second magnetic powder, the softening point temperature of the second glass material is in the range of 300°C to 430°C, and the second glass material softens in the filling step to bond the first magnetic powder coated with the first insulating material to the second magnetic powder.

[0035] In one embodiment, the first glass material comprises a glass powder having a D50 of no more than 1 μm.

[0036] In one embodiment, the weight of the first glass material is no more than 4% of the total weight of the first magnetic powder and the first glass material.

[0037] In one embodiment, the thickness of the first glass material on the outer surface of each of the plurality of particles coated with the first magnetic powder is no greater than 50 nm.

[0038] In one embodiment, the weight of the second glass material is no more than 8% of the total weight of the magnetic material.

[0039] The present invention also provides an electrical component comprising: a plurality of magnetic layers stacked on top of each other, wherein each magnetic layer comprises a magnetic powder and a first insulating material coated on the outer surface of each of a plurality of particles of the magnetic powder to insulate each of the plurality of particles of the magnetic powder, wherein the magnetic powder comprises an amorphous magnetic powder or a nanocrystalline magnetic powder, and the first insulating material comprises glass with a softening point in the range of 300°C to 430°C, wherein each magnetic layer is provided with a corresponding conductive pattern.

[0040] In one embodiment, the electrical component is an inductor, wherein the conductive pattern forms a coil.

[0041] In one embodiment, the electrical component further includes a second insulating material filling the spaces between a plurality of particles of the first magnetic powder coated with the first insulating material, wherein the second insulating material comprises glass with a softening point in the range of 300°C to 430°C.

[0042] In one embodiment, the thickness of the first insulating material on the outer surface of each of the plurality of particles coated with the magnetic powder is in the range of 20 to 800 nm.

[0043] In one embodiment, the first insulating material comprises at least one of the following: SnO-P2O5, V2O5-TeO2, Bi2O3-B2O3, and ZnO.

[0044] In one embodiment, the first insulating material is made of glass with a softening point in the range of 300°C to 430°C.

[0045] In one embodiment, the first insulating material is made of glass with a softening point in the range of 330°C to 430°C.

[0046] In one embodiment, the second insulating material is made of glass with a softening point in the range of 300°C to 430°C.

[0047] In one embodiment, the second insulating material is made of glass with a softening point in the range of 330°C to 430°C.

[0048] In one embodiment, the first insulating material and the second insulating material are the same.

[0049] In one embodiment, both the first insulating material and the second insulating material are made of glass with a softening point in the range of 300°C to 430°C. Attached Figure Description

[0050] Figure 1A The invention illustrates a coating step for fabricating a mixture for forming a magnetic layer in a multilayer inductor, according to one embodiment of the present invention.

[0051] Figure 1B The invention illustrates a filling step for fabricating a mixture for forming a magnetic layer in a multilayer inductor according to an embodiment of the present invention;

[0052] Figure 2A A cross-sectional view of a multilayer inductor structure according to an embodiment of the present invention is shown;

[0053] Figure 2B A schematic cross-sectional view of the magnetic layer of a multilayer inductor structure according to an embodiment of the present invention is shown.

[0054] Figure 2C A top view of a multilayer inductor structure according to an embodiment of the present invention is shown.

[0055] Explanation of icon numbers:

[0056] 101 First Magnetic Powder

[0057] 102 First Glass Material

[0058] 103 The first magnetic powder to be coated

[0059] 104 Second Magnetic Powder

[0060] 105 Second Glass Material

[0061] 106 Mixture

[0062] AA' direction

[0063] 200, 200B magnetic layer structure

[0064] 201 Magnetic Layer

[0065] 202a, 202b conductive patterns

[0066] E1, E2 magnetic layers

[0067] Magnetic layers 301, 302, 303, 304 Detailed Implementation

[0068] The present invention will be further described below with reference to specific embodiments, and the advantages and features of the present invention will become clearer as a result. However, these embodiments are merely exemplary and do not constitute any limitation on the scope of the present invention. Those skilled in the art should understand that modifications or substitutions can be made to the details and form of the technical solutions of the present invention without departing from the spirit and scope of the present invention, but all such modifications and substitutions fall within the protection scope of the present invention.

[0069] This invention provides a mixture for forming multilayer inductors at ultra-low sintering temperatures, and for forming an oxide layer on the surface of heat-treated amorphous or nanocrystalline magnetic powder particles, or for at least partially coating the surface of amorphous or nanocrystalline powder particles with glass material by mechanical fusion, wherein the amorphous or nanocrystalline powder and glass material can be mixed according to different particle sizes and ratios. The binder can then be removed in air to form an oxide layer on the surface of the amorphous or nanocrystalline magnetic powder particles, thereby increasing the insulating strength of the magnetic powder. The mixture can also be sintered under nitrogen to bond the glass material with the magnetic powder, improving the sintering strength.

[0070] Please refer to Figure 1A The invention discloses a method for producing a mixture for forming a multilayer inductor, the method comprising: providing a first magnetic powder 101, wherein the first magnetic powder 101 comprises amorphous magnetic powder or nanocrystalline magnetic powder; and coating the outer surface of each of a plurality of particles of the first magnetic powder 101 with a first insulating material to form a coated first magnetic powder 103, wherein the first insulating material comprises a first glass material 102, the first glass material 102 having a softening point temperature in the range of 300°C to 430°C.

[0071] In one embodiment, the softening point temperature of the first glass material 102 is in the range of 330°C to 430°C.

[0072] Please refer to Figure 1B In one embodiment, the method further includes a filling step, in which a second magnetic powder 104 and a second insulating material are filled into the spaces between a plurality of particles of the coated first magnetic powder 103 to form a mixture 106, wherein the second insulating material includes a second glass material 105, the D50 of the first magnetic powder 101 is greater than the D50 of the second magnetic powder 104, the softening point temperature of the second glass material 105 is in the range of 300°C to 430°C, and the second glass material 105 is softened in the filling step to allow the plurality of particles of the coated first magnetic powder 103 to bond with the second magnetic powder 104.

[0073] In one embodiment, oxygen is added during the combustion sintering process of a polymer material to form an oxide layer on the surface of a first magnetic powder to achieve an insulating effect, wherein the weight of oxygen is no more than 20% relative to the weight of the polymer material.

[0074] In one embodiment, prior to the filling step, the second magnetic powder is heated to form an oxide layer on the surface of each particle of the second magnetic powder, wherein the thickness of the oxide layer on the surface of the second magnetic powder is not greater than 10 nm.

[0075] In one embodiment, a mixture for forming a multilayer inductor is provided, the mixture comprising a first magnetic powder, a second magnetic powder, and a glass material, wherein the D50 of the first magnetic powder is greater than the D50 of the second magnetic powder, and each of the first and second magnetic powders comprises an amorphous magnetic powder or a nanocrystalline magnetic powder, and the softening point temperature of the glass material is 300–430°C.

[0076] In one embodiment, the first magnetic powder comprises Fe, Cr, Si, B, and C.

[0077] In one embodiment, the second magnetic powder comprises Fe, Cr, Si, B, and C.

[0078] In one embodiment, the D50 of the second magnetic powder is 1 to 2 μm, where D50 is the particle size value corresponding to a cumulative percentage of particle number reaching 50%.

[0079] In one embodiment, the glass material comprises glass powder, and the D50 of the glass powder is not greater than 1 μm.

[0080] In one embodiment, the D50 of the first magnetic powder is at least 7 times that of the second magnetic powder.

[0081] In one embodiment, the glass material comprises Bi, Zn, and B.

[0082] In one embodiment, the volume of the second magnetic powder accounts for 20-40% of the total volume of the mixture.

[0083] In one embodiment, the weight of the first glass material is no more than 4% of the total weight of the first magnetic powder and the first glass material.

[0084] In one embodiment, the weight of the second glass material is no more than 8% of the total weight of the magnetic material.

[0085] In one embodiment, an oxide layer is coated on the outer surface of each of the plurality of particles of the second magnetic powder, and the coating thickness of the oxide layer is not greater than 10 nm.

[0086] In one embodiment, the first glass material 102 may partially coat the first magnetic powder 101, and each of the second magnetic powder 104 and the first glass material 102 and the second glass material 105 may be in powder form for manufacturing a magnetic sheet, which may be used to form a multilayer inductor or a multilayer power inductor using a lamination method.

[0087] In one embodiment, the first magnetic powder 103, the second magnetic powder 104, the second glass material 105 to be coated can be mixed evenly with an adhesive material to form a slurry, and then the mixture can be spread on a carrier film by a doctor blade forming step to obtain a magnetic sheet.

[0088] In one embodiment, the proportion of the adhesive material, such as glue, to the total weight of the mixture is 1.1% to 2%. If the weight proportion of the adhesive material is not greater than 1.1%, the magnetic sheet will have a loose and inflexible structure; if the weight proportion of the adhesive material exceeds 2%, the magnetic permeability of the magnetic sheet will decrease.

[0089] In one embodiment, the magnetic sheet is stacked and stamped to form a toroidal inductor with an outer diameter of 14 mm, an inner diameter of 8 mm, and a thickness of 1 to 3 mm, wherein the magnetic sheet is formed by sintering a mixture in air with an oxygen content greater than 20% and a temperature not greater than 470°C.

[0090] In one embodiment, the magnetic sheet is stacked and stamped to form a sheet of 100-150 μm, wherein the magnetic sheet is formed by sintering a mixture in air with an oxygen content greater than 20% and a temperature not greater than 450°C.

[0091] In one embodiment, a mixture for forming a multilayer inductor is provided, the mixture comprising: a first magnetic powder and a first insulating material, wherein the first magnetic powder comprises an amorphous magnetic powder or a nanocrystalline magnetic powder, the first insulating material comprises a first glass material having a softening point temperature in the range of 300°C to 430°C, wherein the first insulating material is coated on the outer surface of each of a plurality of particles of the first magnetic powder to insulate each of the plurality of particles of the first magnetic powder.

[0092] In one embodiment, the mixture further includes a second insulating material filling the spaces between multiple particles of the first magnetic powder coated with the first insulating material, wherein the second insulating material comprises a second glass material having a softening point in the range of 300°C to 430°C.

[0093] In one embodiment, the mixture further includes a second insulating material filling the spaces between multiple particles of the coated first magnetic powder, wherein the second insulating material comprises a second glass material having a softening point in the range of 300°C to 430°C.

[0094] In one embodiment, the thickness of the first insulating material coated on the outer surface of each of the plurality of particles in the first magnetic powder is in the range of 20 to 800 nm.

[0095] In one embodiment, the first insulating material comprises at least one of the following: SnO-P2O5, V2O5-TeO2, Bi2O3-B2O3, and ZnO.

[0096] In one embodiment, the first insulating material comprises at least one of the following: SnO-P2O5, V2O5-TeO2, Bi2O3-B2O3, ZnO, and A2O-MoO3.

[0097] In one embodiment, the first insulating material is made of glass with a softening point in the range of 300°C to 430°C.

[0098] In one embodiment, the first insulating material is made of glass with a softening point in the range of 330°C to 430°C.

[0099] In one embodiment, the second insulating material is made of glass with a softening point in the range of 300°C to 430°C.

[0100] In one embodiment, the second insulating material is made of glass with a softening point in the range of 330°C to 430°C.

[0101] In one embodiment, the first insulating material and the second insulating material are the same.

[0102] In one embodiment, both the first insulating material and the second insulating material are made of glass with a softening point in the range of 300°C to 430°C.

[0103] In one embodiment, the D50 of the first magnetic powder is in the range of 0.5 to 40 μm.

[0104] In one embodiment, the first magnetic powder comprises at least one of the following: iron-silicon-boron-carbon-chromium-niobium-copper, iron-silicon-boron-carbon-chromium, iron-silicon-boron-carbon, and iron-silicon-boron-carbon-chromium-niobium-phosphorus.

[0105] In one embodiment, the D50 of the second magnetic powder is 1 to 2 μm, and the D50 of the first magnetic powder is at least 7 times that of the second magnetic powder.

[0106] In one embodiment, the volume of the second magnetic powder accounts for 20-40% of the total volume of the mixture.

[0107] In one embodiment, the weight of the first glass material is no more than 4% of the total weight of the first magnetic powder and the first glass material.

[0108] In one embodiment, the second glass material fills the space between the particles of the second magnetic powder and the particles of the first magnetic powder.

[0109] In one embodiment, the first insulating material comprises glass powder, wherein the D50 of the glass powder is not greater than 1 μm.

[0110] In one embodiment, the weight of the second glass material is no more than 8% of the total weight of the magnetic material.

[0111] In one embodiment, the thickness of the first glass material on the outer surface of each of the plurality of particles coated with the first magnetic powder is no greater than 50 nm.

[0112] In one embodiment, oxygen is added during the combustion sintering process of a polymer material to form an oxide layer on the surface of a first magnetic powder to achieve an insulating effect, wherein the weight of oxygen is no more than 20% relative to the weight of the polymer material.

[0113] Please refer to Figure 2A The diagram shows a cross-sectional view of a magnetic layer structure 200 along the A-A' direction. The magnetic layer structure 200 includes a magnetic layer 201 for forming a coil. The magnetic layer contains a magnetic powder and a first insulating material coated on the outer surface of each of a plurality of particles of the magnetic powder to insulate each of the plurality of particles of the magnetic powder. The magnetic powder contains an amorphous magnetic powder or a nanocrystalline magnetic powder. The first insulating material comprises glass with a softening point in the range of 300°C to 430°C. Conductive patterns 202a and 202b are disposed on the magnetic layer to form a coil.

[0114] In one embodiment, a trench may be formed in the magnetic layer 201, wherein conductive patterns 202a, 202b may be disposed in a trench of the magnetic layer to form a coil.

[0115] Figure 2BA cross-sectional view of a magnetic layer structure 200B along the A-A' direction is shown. The magnetic layer structure 200B includes multiple magnetic layers E1, 301, 302, 303, 304, and E2 for forming a multilayer inductor with a coil. Each magnetic layer includes a magnetic powder and a first insulating material coated on the outer surface of each of the multiple particles of the magnetic powder to insulate each of the multiple particles of the magnetic powder. The magnetic powder comprises an amorphous magnetic powder or a nanocrystalline magnetic powder. The first insulating material comprises glass with a softening point in the range of 300°C to 430°C. A coil is disposed in the magnetic layer.

[0116] In one embodiment, trenches can be formed in each magnetic layer 301, 302, 303, 304, wherein the conductive patterns 202a, 202b corresponding to each magnetic layer can be disposed in the corresponding trenches to form a coil.

[0117] refer to Figure 2C It shows a top view of structure 200B along the A-A' direction, and shows a corresponding top view of each magnetic layer E2, 301, 302, 303, 304, E1, wherein coils are formed in multiple magnetic layers E2, 301, 302, 303, 304, E1 to form an inductor.

[0118] In one embodiment, an electrical component is provided, comprising: a plurality of magnetic layers stacked on top of each other, wherein each magnetic layer comprises a magnetic powder and a first insulating material coated on the outer surface of each of a plurality of particles of the magnetic powder to insulate each of the plurality of particles of the magnetic powder, wherein the magnetic powder comprises an amorphous magnetic powder or a nanocrystalline magnetic powder, and the first insulating material comprises glass with a softening point in the range of 300°C to 430°C, wherein each magnetic layer is provided with a corresponding conductive pattern.

[0119] In one embodiment, the electrical component is an inductor, wherein the conductive pattern forms a coil.

[0120] In one embodiment, a second insulating material is further included, filling the spaces between a plurality of particles of the first magnetic powder coated with the first insulating material, wherein the second insulating material comprises glass with a softening point in the range of 300°C to 430°C.

[0121] In one embodiment, the thickness of the first insulating material on the outer surface of each of the plurality of particles coated with the magnetic powder is in the range of 20 to 800 nm.

[0122] In one embodiment, the thickness of the first insulating material on the outer surface of each of the plurality of particles coated with the magnetic powder is no greater than 50 nm.

[0123] In one embodiment, the first insulating material comprises at least one of the following: SnO-P2O5, V2O5-TeO2, Bi2O3-B2O3, and ZnO.

[0124] In one embodiment, the first insulating material is made of glass with a softening point in the range of 300°C to 430°C.

[0125] In one embodiment, the second insulating material is made of glass with a softening point in the range of 300°C to 430°C.

[0126] In one embodiment, the first insulating material is made of glass with a softening point in the range of 330°C to 430°C.

[0127] In one embodiment, the second insulating material is made of glass with a softening point in the range of 330°C to 430°C.

[0128] In one embodiment, the first insulating material and the second insulating material are the same.

[0129] In one embodiment, both the first insulating material and the second insulating material are made of glass with a softening point in the range of 300°C to 430°C.

Claims

1. A mixture for forming a multilayer inductor, characterized in that: The mixture comprises a first magnetic powder, a second magnetic powder, and a first glass material, wherein the D50 of the first magnetic powder is greater than that of the second magnetic powder, and each of the first and second magnetic powders comprises either an amorphous magnetic powder or a nanocrystalline magnetic powder. The first glass material coats the outer surface of each of the plurality of particles of the first magnetic powder, and the first glass material comprises SnO-P2O5, V2O5-TeO2, or Bi2O3-B2O3, and the softening temperature of the first glass material is 300°C to 430°C. A second glass material fills a space between the particles of the plurality of first magnetic powders coated with the first glass material, and the softening temperature of the second glass material is also 300°C to 430°C. The second glass material filling the space is softened to bond the first magnetic powder and the second magnetic powder.

2. The mixture according to claim 1, characterized in that: The first magnetic powder comprises Fe, Cr, Si, B, and C.

3. The mixture according to claim 1, characterized in that: The second magnetic powder comprises Fe, Cr, Si, B, and C.

4. The mixture according to claim 1, characterized in that: The D50 of the second magnetic powder is 1-2 μm.

5. The mixture according to claim 1, characterized in that: The D50 of the first magnetic powder is at least 7 times that of the second magnetic powder.

6. The mixture according to claim 1, characterized in that: The first glass material comprises a glass powder, and the D50 of the glass powder is not greater than 1 μm.

7. The mixture according to claim 1, characterized in that: The first glass material is the same as the second glass material, including SnO-P2O5, V2O5-TeO2 or Bi2O3-B2O3. The second glass material is softened to bond the first magnetic powder and the second magnetic powder.

8. The mixture according to claim 1, characterized in that: The volume of the second magnetic powder accounts for 20-40% of the total volume of the mixture.

9. The mixture according to claim 1, characterized in that: The thickness of the first glass material covering the outer surface of each of the plurality of particles of the first magnetic powder is no greater than 50 nm.

10. The mixture according to claim 1, characterized in that: An oxide layer covers the outer surface of each of the plurality of particles of the second magnetic powder, and the thickness of the oxide layer is not greater than 10 nm.

11. The mixture according to claim 1, characterized in that: The mixture is sintered in air with an oxygen content greater than 20% and a temperature not exceeding 470°C to form a magnetic sheet.

12. A method for producing a mixture for forming a multilayer inductor, characterized in that: The method includes the following steps: A first magnetic powder is provided, wherein the first magnetic powder comprises an amorphous magnetic powder or a nanocrystalline magnetic powder; A first insulating material is coated on the outer surface of each of the plurality of particles of the first magnetic powder, wherein the first insulating material includes a first glass material, the first glass material includes SnO-P2O5, V2O5-TeO2 or Bi2O3-B2O3 and the softening point temperature of the first glass material is in the range of 300℃ to 430℃. A second magnetic powder and a second glass material are filled into a space between multiple particles of the first magnetic powder coated with the first glass material, wherein the softening point temperature of the second glass material is in the range of 300°C to 430°C; and A magnetic sheet is formed by sintering at a temperature not exceeding 470°C, wherein the second glass material filling the space is softened to bond the first magnetic powder and the second magnetic powder together.

13. The method according to claim 12, characterized in that: The first magnetic powder has a greater D50 than the second magnetic powder, and the softening point temperature of the second glass material is in the range of 300℃ to 430℃.

14. The method according to claim 12, characterized in that: The first glass material comprises a glass powder having a D50 of no more than 1 μm.

15. The method according to claim 12, characterized in that: The weight of the first glass material is no more than 4% of the total weight of the first magnetic powder and the first glass material.

16. The method according to claim 12, characterized in that: The thickness of the first glass material on the outer surface of each of the plurality of particles coated with the first magnetic powder is no greater than 50 nm.

17. The method according to claim 13, characterized in that: The weight of the second glass material is no more than 8% of the total weight of the magnetic material composed of the first magnetic powder and the second magnetic powder.

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