Coil-type electronic component

Abstract

A coil-type electronic component, wherein the electronic component includes an element having a magnetic substance and a coil conductor, the magnetic substance between layers of the coil conductor located adjacent in an axial direction of the coil conductor includes first soft magnetic metal particles, the magnetic substance located outside in the axial direction includes second soft magnetic metal particles, and the first soft magnetic metal particles have a higher saturation magnetization (Ms) than the second soft magnetic metal particles.

Description

Technical Field

[0001] This invention relates to coil-type electronic components. Background Technology

[0002] Patent document 1 describes an invention concerning soft magnetic alloy powder, characterized in that it contains Fe-Ni based particles in which the contents of Fe, Ni, Co and Si are each controlled within a specific range.

[0003] However, while laminated coils using Fe-Ni particles as magnetic materials have high inductance, they also suffer from low DC superposition characteristics.

[0004] Existing technical documents:

[0005] Patent Document 1: Japanese Patent Application Publication No. 2008-135674 Summary of the Invention

[0006] [The technical problem that the invention aims to solve]

[0007] The purpose of this invention is to provide coil-type electronic components with sufficiently high inductance (L) and DC superposition characteristics (Idc).

[0008] [Methods used to solve technical problems]

[0009] In the coil-type electronic component involved in this invention, the electronic component includes an element having a magnetic element and a coil conductor. The magnetic element located between layers of the coil conductor adjacent to each other in the axial direction of the coil conductor includes a first soft magnetic metal particle, and the magnetic element located on the outer side along the axis includes a second soft magnetic metal particle. The first soft magnetic metal particle has a higher saturation magnetization intensity than the second soft magnetic metal particle.

[0010] The coil-type electronic component involved in this invention has sufficiently high inductance and DC superposition characteristics due to the structure described above.

[0011] The first soft magnetic metal particle is preferably an Fe-Si alloy. This allows for a further increase in the saturation magnetization of the first soft magnetic metal particle. Consequently, the saturation magnetization of the first soft magnetic metal particle is more easily made higher than that of the second soft magnetic metal particle, thus significantly improving inductance and DC superposition characteristics.

[0012] The second soft magnetic metal particle is preferably an Fe-Ni alloy. This makes it easier to make the saturation magnetization of the first soft magnetic metal particle higher than that of the second soft magnetic metal particle, thus significantly improving inductance and DC superposition characteristics.

[0013] Preferably, the inner diameter of the second magnetic element, which is present in at least a portion of the inner diameter region of the shaft of the element containing the coil conductor, comprises the second soft magnetic metal particles.

[0014] In a cross-section perpendicular to the axis of the coil conductor, the area of ​​the second magnetic element with the inner diameter preferably accounts for 30% or more of the area of ​​the inner diameter region at the center of the axis. This allows for a higher balance between inductance and DC superposition characteristics.

[0015] The average particle size of the aforementioned first soft magnetic metal particles is preferably 1 to 6 μm. When the average particle size of the first soft magnetic metal particles is 1 to 6 μm, the inductance can be improved compared to when the average particle size is less than 1 μm. Furthermore, when the average particle size of the first soft magnetic metal particles is 1 to 6 μm, compared to when the average particle size exceeds 6 μm, the inductance can be improved, plating elongation can be suppressed, and the number of short circuits can be reduced.

[0016] The average particle size of the aforementioned second soft magnetic metal particles is preferably 1 to 15 μm. When the average particle size of the second soft magnetic metal particles is 1 to 15 μm, the inductance can be improved compared to when the average particle size is less than 1 μm. Furthermore, when the average particle size of the second soft magnetic metal particles is 1 to 15 μm, compared to when the average particle size exceeds 15 μm, the DC superposition characteristics can be improved, electroplating elongation can be suppressed, and the number of short circuits can be reduced.

[0017] Preferably, at least a portion of the outer diameter of the second magnetic element located radially outside the coil conductor, in the central outer diameter region of the element, comprises the second soft magnetic metal particles. This further enhances the inductance.

[0018] In a cross-section perpendicular to the axis of the coil conductor, the area of ​​the second magnetic element with the outer diameter can account for 15% or more of the area of ​​the outer diameter region at the center of the axis. This further improves the DC superposition characteristics. Attached Figure Description

[0019] Figure 1 This is a perspective view of a stacked coil according to one embodiment of the present invention.

[0020] Figure 1A It is along Figure 1 A rough cross-sectional view of the IA-IA line.

[0021] Figure 1A1 It is along Figure 1 A rough cross-sectional view of the IAI-IAI line.

[0022] Figure 1B This is a general cross-sectional view of a stacked coil according to another embodiment of the present invention.

[0023] Figure 1C This is a general cross-sectional view of a stacked coil according to another embodiment of the present invention.

[0024] Figure 1D This is a general cross-sectional view of a stacked coil according to another embodiment of the present invention.

[0025] Figure 1E This is a general cross-sectional view of a stacked coil according to another embodiment of the present invention.

[0026] Figure 2a yes Figure 1A The diagram illustrates the manufacturing method of the laminated coil.

[0027] Figure 2b yes Figure 1A The diagram illustrates the manufacturing method of the laminated coil.

[0028] Figure 2c yes Figure 1A The diagram illustrates the manufacturing method of the laminated coil.

[0029] Figure 2d yes Figure 1A The diagram illustrates the manufacturing method of the laminated coil.

[0030] Figure 2e yes Figure 1A The diagram illustrates the manufacturing method of the laminated coil.

[0031] Figure 2f yes Figure 1A The diagram illustrates the manufacturing method of the laminated coil.

[0032] Figure 2g yes Figure 1A The diagram illustrates the manufacturing method of the laminated coil.

[0033] Figure 2h yes Figure 1A The diagram illustrates the manufacturing method of the laminated coil.

[0034] Figure 3 This is a general cross-sectional view of a stacked coil according to another embodiment of the present invention.

[0035] Figure 4 This is a perspective view of a stacked coil according to another embodiment of the present invention.

[0036] Figure 4A It is along Figure 4A rough cross-sectional view of the IVA-IVA line.

[0037] Figure 5A This is a general cross-sectional view of the laminated coil involved in the comparative example of the present invention.

[0038] Figure 5B This is a general cross-sectional view of the laminated coil involved in the comparative example of the present invention.

[0039] Figure 5C This is a general cross-sectional view of the laminated coil involved in the comparative example of the present invention.

[0040] Figure 6 It is a graph where the X-axis represents the proportion (%) of the second magnetic element with inner diameter, and the Y-axis represents (ΔL / L) + (ΔIdc / Idc) (%).

[0041] Symbol Explanation

[0042] 1...Layered coils

[0043] 2... Components

[0044] 2a1, 2a2... shaft end region

[0045] 2b……Central region of axis

[0046] 24ba……Axis Central Coil Region

[0047] 24ba1……Interlayer area

[0048] 24bb……Inner diameter area of ​​the shaft center

[0049] 24bc……Axis central outer diameter region

[0050] 3……Terminal electrodes

[0051] 4...Magnetic Element

[0052] 4a……coil region

[0053] 4b...Inner diameter area

[0054] 4c……Outer diameter region

[0055] 40……First Magnetic Element

[0056] 40a……First interlayer magnetic element

[0057] 40b... First magnetic element with inner diameter

[0058] 40c……Outer diameter first magnetic element

[0059] 400a~400h……First raw film

[0060] 42……Second Magnetic Element

[0061] 42a1, 42a2... Second magnetic element at the shaft end

[0062] 42a……Second magnetic element between layers

[0063] 42b……Second magnetic element with inner diameter

[0064] 42c……Second magnetic element with outer diameter

[0065] 420a~420h……Second raw film

[0066] 5……coil conductor

[0067] 501, 502... Second layer outer coil conductor

[0068] 503, 504... Second layer inner coil conductor

[0069] 505, 506... Third layer inner coil conductor

[0070] 521, 522... Seventh layer inner coil conductor

[0071] 523, 524... Seventh layer outer coil conductor

[0072] 525, 526... Eighth layer outer coil conductor

[0073] 527, 528... the inner coil conductor of the eighth layer

[0074] 50b, 50b1, 50c, 50c1, 50c2, 50d, 50d1, 50e, 50e1, 50f, 50f1, 50f2, 50g, 50g1... conductors

[0075] 5a1, 5a2... Lead-out electrodes

[0076] 50A1, 50A2... conductors

[0077] 100a~100h……Print Detailed Implementation

[0078] (First Implementation)

[0079] The following is one embodiment of the coil-type electronic component involved in this embodiment. Figure 1 The layered coil 1 shown will be explained.

[0080] like Figure 1As shown, the laminated coil 1 according to this embodiment has an element 2 and terminal electrodes 3. The element 2 has a structure in which a coil conductor 5 is embedded in a three-dimensional spiral shape inside a magnetic body 4. Terminal electrodes 3 are formed at both ends of the element 2, and the terminal electrodes 3 are connected to the coil conductor 5 via lead-out electrodes 5a1 and 5a2. Furthermore, in Figure 1 And the following Figures 1A to 1E , Figure 1A1 , Figure 3 , Figure 4 , Figure 4A , Figures 5A to 5C In the diagram, the X-axis, Y-axis, and Z-axis are perpendicular to each other.

[0081] In addition, in this embodiment, "inner side" refers to the side closer to the center of the laminated coil 1 (the axis N of the coil conductor 5), and "outer side" refers to the side farther away from the center of the laminated coil 1.

[0082] The material of the terminal electrode 3 can be any conductive material, without particular limitations. For example, Ag, Cu, Au, Al, Ag alloys, Cu alloys, etc., can be used. In particular, Ag is preferred because it is inexpensive and has low resistance. The terminal electrode 3 may contain glass powder. In addition, the terminal electrode 3 may also have a two-layer structure, consisting of a metal layer formed on the element 2 and composed of the aforementioned metal or a mixture of the aforementioned metal and glass powder, and a resin layer formed on the metal layer and composed of conductive resin. There are no particular limitations on the type of metal contained in the conductive resin. For example, Ag can be used. Furthermore, the terminal electrode 3 may also be electroplated. For example, Cu electroplating, Ni electroplating, Sn electroplating, Cu-Ni-Sn electroplating, and / or Ni-Sn electroplating may be appropriately performed.

[0083] The coil conductor 5 and the lead electrodes 5a1 and 5a2 can be made of any conductive material, and can be any material. For example, Ag, Cu, Au, Al, Ag alloys, Cu alloys, etc. can be used. In particular, Ag is preferred because it is inexpensive and has low resistance. The coil conductor 5 may also contain glass powder.

[0084] The number of turns of the coil conductor 5 around the axis N is not particularly limited, for example, it is 1.5 to 15.5. In addition, the thickness (Te) of the coil conductor 5 is not particularly limited, for example, it is 5 to 60 μm.

[0085] Figure 1A It is along Figure 1 The approximate cross-sectional view of the IA-IA line is a cross-sectional view parallel to the YZ axis. That is, Figure 1A It is a cross-sectional view that shows the lead-out electrodes 5a1, 5a2 and the terminal electrode 3.

[0086] like Figure 1AAs shown, element 2 can be divided from below along the winding axis N (parallel to the Z axis) of coil conductor 5 into shaft end region 2a1, shaft center region 2b and shaft end region 2a2.

[0087] In other words, component 2 can be divided into a central region 2b on the axis where the coil conductor 5 is embedded, and upper and lower end regions 2a1 and 2a2 on the axis of the central region 2b in the Z-axis direction where the coil conductor 5 is not embedded. It should be noted that the axis of the coil conductor 5 is parallel to the stacking direction of the coil conductor 5.

[0088] Specifically, perpendicular to the axial direction (Z-axis direction), with an imaginary line along the outer side of the lead-out electrodes 5a1 and 5a2 as the boundary, the outer side along the axial center N is designated as the axial end region 2a1 and 2a2, and the inner side is designated as the axial central region 2b. In this embodiment, the axial central region 2b is defined as the area encompassing the lead-out electrodes 5a1 and 5a2.

[0089] In addition, the element 2 can be divided in the radial direction (Y-axis direction) perpendicular to the axis direction into an inner diameter region 4b of the coil conductor 5, a coil region 4a with the coil conductor 5 wound around it, and an outer diameter region 4c located on the radial outer side of the coil conductor 5.

[0090] In this embodiment, as described above, the region of element 2 is divided into shaft end regions 2a1, 2a2 and shaft center region 2b in the Z-axis direction, and into inner diameter region 4b, coil region 4a and outer diameter region 4c in the radial direction.

[0091] Furthermore, in this embodiment, the region located in the central region 2b and the inner diameter region 4b is designated as the central inner diameter region 24bb. Additionally, the region located in the central region 2b and the coil region 4a is designated as the central coil region 24ba. Finally, the region located in the central region 2b and the outer diameter region 4c is designated as the central outer diameter region 24bc.

[0092] In this embodiment, the region of the element 2 located at the midpoint between adjacent coil conductors 5 in the axial direction of the central coil region 24ba is defined as the interlayer region 24ba1. The thickness (Ti) of the interlayer region 24ba1 in the Z-axis direction is not particularly limited, and is, for example, 5 to 100 μm.

[0093] The magnetic element 4 involved in this embodiment is configured in a predetermined arrangement to form a first magnetic element 40 containing first soft magnetic metal particles and a second magnetic element 42 containing second soft magnetic metal particles.

[0094] In this embodiment, the first magnetic element 40 is composed of an interlayer first magnetic element 40a located in the central coil region 24ba of the shaft, an inner diameter first magnetic element 40b located in the inner diameter region 24bb of the shaft, and an outer diameter first magnetic element 40c located in the outer diameter region 24bc of the shaft.

[0095] In addition, the second magnetic element 42 is composed of the shaft end second magnetic elements 42a1 and 42a2 located in the shaft end regions 2a1 and 2a2, the inner diameter second magnetic element 42b located in the inner diameter region 24bb in the center of the shaft, and the outer diameter second magnetic element 42c located in the outer diameter region 24bc in the center of the shaft.

[0096] Specifically, such as Figure 1A As shown, the interlayer region 24ba1 of the coil conductor 5 is composed of an interlayer first magnetic element 40a containing first soft magnetic metal particles.

[0097] The inner diameter first magnetic element 40b is continuously formed from the interlayer first magnetic element 40a. It should be noted that the shape of the inner diameter first magnetic element 40b is not particularly limited, for example, it is preferably substantially rectangular along the central region 2b of the axis. It should be noted that, in this embodiment, "substantially rectangular" means that the outline of the rectangle may have some uneven or sloping portions.

[0098] Moreover, such as Figure 1A As shown, the outer diameter first magnetic element 40c is continuously formed from the interlayer first magnetic element 40a. It should be noted that the shape of the outer diameter first magnetic element 40c is not particularly limited, for example, it is preferably substantially rectangular along the central region 2b of the axis.

[0099] In this embodiment, the shaft end regions 2a1 and 2a2 located on the outer side of the coil conductor 5 are composed of shaft end second magnetic elements 42a1 and 42a2.

[0100] The second magnetic element 42 can also constitute the portion other than the shaft end regions 2a1 and 2a2. For example, as Figure 1A As shown, an inner diameter second magnetic element 42b may also be provided, which continuously forms part of the inner diameter region 24bb at the center of the shaft of the coil conductor 5 from the second magnetic elements 42a1 and 42a2 at the shaft ends. In other words, the inner diameter second magnetic element 42b may also form the inner side of the inner diameter first magnetic element 40b in the inner diameter region 24bb at the center of the shaft. It should be noted that, preferably, the inner diameter second magnetic element 42b is substantially rectangular along the central region 2b of the shaft.

[0101] It should be noted that, in the above, along Figure 1AThe YZ cross-sectional diagram is illustrated, but in the cross-section containing the axis N of the coil conductor 5, the same structure is formed in any cross-section, for example, the same structure is formed in the ZX cross-sectional diagram.

[0102] Figure 1A1 It is along Figure 1 A cross-sectional view of the IAI-IAI line. That is, Figure 1A1 This is a cross-sectional view of the central region 2b of the shaft, perpendicular to the axis N of the coil conductor 5. In this cross-section perpendicular to the axis N of the coil conductor 5 in the central region 2b, the boundary between the central coil region 24ba and the central inner diameter region 24bb is represented by a dashed line as the inner diameter boundary line R. Furthermore, the boundary between the central coil region 24ba and the central outer diameter region 24bc is represented by a dashed line as the outer diameter boundary line S. The coil conductor 5 is stacked in a spiral manner, therefore, as shown... Figure 1A1 As shown, in a cross-section perpendicular to the axis, a portion of the central coil region 24ba does not have a coil conductor 5, but has a portion where an interlayer second magnetic element 42a is disposed. That is, the portion where the interlayer second magnetic element 42a is disposed is the interlayer region 24ba1.

[0103] In this embodiment, in the cross-section perpendicular to the axis N of the coil conductor 5 in the central region 2b, the ratio of the area of ​​the inner diameter second magnetic element 42b to the area of ​​the central inner diameter region 24bb (hereinafter referred to as the "inner diameter second magnetic element ratio") is preferably 30% or more, more preferably 30% to 75%. In this embodiment, in the cross-section perpendicular to the axis N of the coil conductor 5 in the central region 2b, the central inner diameter region 24bb is the region inside the inner diameter boundary line R.

[0104] Furthermore, in the cross-section perpendicular to the axis N of the coil conductor 5 in the central region 2b, the ratio of the area of ​​the outer diameter second magnetic element 42c to the area of ​​the central outer diameter region 24bc (hereinafter referred to as the "outer diameter second magnetic element ratio") is preferably 15% or more, more preferably 15% to 50%. In this embodiment, in the cross-section perpendicular to the axis N of the coil conductor 5 in the central region 2b, the central outer diameter region 24bc is the region outside the outer diameter boundary line S.

[0105] In this embodiment, the first soft magnetic metal particle has a higher saturation magnetization (Ms) than the second soft magnetic metal particle. When the saturation magnetization of the first soft magnetic metal particle is defined as "first Ms" and the saturation magnetization of the second soft magnetic metal particle is defined as "second Ms", the ratio (first Ms / second Ms) is preferably 1.07 to 1.80, more preferably 1.16 to 1.50. It should be noted that, hereinafter, "first soft magnetic metal particle" and "second soft magnetic metal particle" are sometimes collectively referred to as "soft magnetic metal particle".

[0106] The material of the first soft magnetic metal particle involved in this embodiment is not particularly limited, and can be, for example, Fe-Si alloy, Fe-Si-Cr alloy, pure Fe, Fe-Ni alloy, or Fe-Si-Al alloy, preferably an Fe-Si alloy. This allows for further improvement in the saturation magnetization of the first soft magnetic metal particle.

[0107] When the total content of Fe and Si in the first soft magnetic metal particles is set to 100% by mass, the Fe content in the first soft magnetic metal particles is preferably 92.0 to 97.0% by mass, more preferably 92.5 to 96.5% by mass.

[0108] When the total content of Fe and Si in the first soft magnetic metal particles is set to 100% by mass, the content of Cr in the first soft magnetic metal particles is preferably 5% by mass or less, more preferably less than 2% by mass. As a result, the balance between inductance and DC superposition characteristics is better, the evaluation of electroplating elongation suppression is higher, and the number of short circuits is reduced.

[0109] When the total content of Fe and Si in the first soft magnetic metal particles is set to 100% by mass, the content of P in the first soft magnetic metal particles is preferably 10 to 700 ppm, more preferably 40 to 650 ppm. This results in a better balance between inductance and DC superposition characteristics, higher evaluation of electroplating elongation suppression, and fewer short circuits.

[0110] When the total content of Fe and Si in the first soft magnetic metal particles is set to 100% by mass, it is preferable that the content of elements other than Fe, Si, Cr, and P in the first soft magnetic metal particles is less than 3% by mass. The elements other than Fe, Si, Cr, and P in the first soft magnetic metal particles are Ni, O, Co, or Al, etc.

[0111] The material of the second soft magnetic metal particle involved in this embodiment is not particularly limited, such as Fe-Ni alloy, Fe-Si-Cr alloy, Fe-Si-Al alloy, and preferably Fe-Ni alloy. This makes it easy to make the saturation magnetization of the first soft magnetic metal particle higher than that of the second soft magnetic metal particle, thus significantly improving inductance and DC superposition characteristics.

[0112] When the total content of Fe, Ni, Si, Co, Cr and P in the second soft magnetic metal particles is set to 100% by mass, the Fe content in the second soft magnetic metal particles is preferably 33.0 to 68.0% by mass, more preferably 37.0 to 55.0% by mass.

[0113] When the total content of Fe, Ni, Si, Co, Cr, and P in the second soft magnetic metal particles is set to 100% by mass, the content of Ni in the second soft magnetic metal particles is preferably 14.0 to 56.0% by mass, more preferably 15.0 to 55.0% by mass. As a result, the balance between inductance and DC superposition characteristics is better, the evaluation of electroplating elongation suppression is higher, and the number of short circuits is less.

[0114] When the total content of Fe, Ni, Si, Co, Cr, and P in the second soft magnetic metal particles is set to 100% by mass, the content of Si in the second soft magnetic metal particles is preferably 2.0 to 6.0% by mass. As a result, the balance between inductance and DC superposition characteristics is better, the evaluation of electroplating elongation suppression is higher, and the number of short circuits is less.

[0115] When the total content of Fe, Ni, Si, Co, Cr, and P in the second soft magnetic metal particles is set to 100% by mass, the content of Co in the second soft magnetic metal particles is preferably 2.0 to 40.0% by mass. As a result, the balance between inductance and DC superposition characteristics is better, the evaluation of electroplating elongation suppression is higher, and the number of short circuits is less.

[0116] When the total content of Fe, Ni, Si, Co, Cr, and P in the second soft magnetic metal particles is set to 100% by mass, the Cr content in the second soft magnetic metal particles is preferably 1.8% by mass or less. This results in a better balance between inductance and DC superposition characteristics.

[0117] When the total content of Fe, Ni, Si, Co, Cr, and P in the second soft magnetic metal particles is set to 100% by mass, the content of P in the second soft magnetic metal particles is preferably 10 to 6000 ppm, more preferably 100 to 5000 ppm. This results in a better balance between inductance and DC superposition characteristics, higher evaluation of electroplating elongation suppression, and fewer short circuits.

[0118] When the total content of Fe, Ni, Si, Co, Cr, and P in the second soft magnetic metal particles is set to 100% by mass, it is preferable that the content of elements other than Fe, Ni, Si, Co, Cr, and P in the second soft magnetic metal particles is less than 3% by mass. It should be noted that the elements other than Fe, Ni, Si, Co, Cr, and P in the second soft magnetic metal particles are, for example, Al or O.

[0119] In this embodiment, the average particle size of the first soft magnetic metal particles is preferably 1 to 6 μm. When the average particle size of the first soft magnetic metal particles is 1 to 6 μm, the inductance can be improved compared to when the average particle size is less than 1 μm. Furthermore, when the average particle size of the first soft magnetic metal particles is 1 to 6 μm, compared to when the average particle size exceeds 6 μm, the inductance can be improved, plating elongation can be suppressed, and the number of short circuits can be reduced.

[0120] The average particle size of the second soft magnetic metal particles involved in this embodiment is preferably 1 to 15 μm. When the average particle size of the second soft magnetic metal particles is 1 to 15 μm, the inductance can be improved compared to when the average particle size is less than 1 μm. Furthermore, when the average particle size of the second soft magnetic metal particles is 1 to 15 μm, compared to when the average particle size exceeds 15 μm, the DC superposition characteristics can be improved, electroplating elongation can be suppressed, and the number of short circuits can be reduced.

[0121] The average particle size of the first soft magnetic metal particles is preferably less than or equal to the average particle size of the second soft magnetic metal particles. When the average particle size of the first soft magnetic metal particles is defined as the "first average particle size" and the average particle size of the second soft magnetic metal particles is defined as the "second average particle size", the ratio of (first average particle size / second average particle size) is preferably 0.2 to 1.0, and more preferably 0.2 to 0.5.

[0122] There is no particular limitation on the method for determining the average particle size of soft magnetic metal particles. In this embodiment, the area of ​​the soft magnetic metal particles is calculated by performing image analysis on the cross-section of the resin-embedded laminated coil 1 (electronic component) using SEM or STEM, and the value (area diameter) calculated as the diameter of a circle equivalent to that area is used as the particle size of the soft magnetic metal particles. The average particle size is the average particle size of the particle size of multiple soft magnetic metal particles.

[0123] It should be noted that there are no particular restrictions on the shape of the soft magnetic metal particles.

[0124] The magnetic matrix 4 according to this embodiment has a structure in which multiple soft magnetic metal particles are interconnected through sintering. Specifically, the elements contained in the soft magnetic metal particles that come into contact with each other through sintering react with other elements (e.g., O), and the multiple soft magnetic metal particles are connected to each other via bonds arising from this reaction. In the magnetic matrix 4 according to this embodiment, soft magnetic metal particles derived from soft magnetic metal powder, which are raw material powders for soft magnetic metal particles, are interconnected through heat treatment, but each soft magnetic metal particle hardly undergoes grain growth.

[0125] Furthermore, the content of the first soft magnetic metal particles in the first magnetic body 40 is preferably 90% by mass or more, more preferably 95% by mass or more. As long as the content of the first soft magnetic metal particles in the first magnetic body 40 is as described above, the first magnetic body 40 may not be entirely composed of the first soft magnetic metal particles. For example, the first magnetic body 40 may also slightly contain metal particles with a saturation magnetization intensity equal to or less than that of the second soft magnetic metal particles.

[0126] Furthermore, the content of the second soft magnetic metal particles in the second magnetic element 42 is preferably 90% by mass or more, more preferably 95% by mass or more. As long as the content of the second soft magnetic metal particles in the second magnetic element 42 is as described above, the second magnetic element 42 may not be entirely composed of the second soft magnetic metal particles. For example, it may contain metal particles with a saturation magnetization intensity equal to or greater than that of the first soft magnetic metal particles.

[0127] Soft magnetic metal particles can also be coated with a film. Specifically, the coating can be an oxide coating, which can also include a layer composed of Si-containing oxides. By coating the soft magnetic metal particles with a film, the insulation between the soft magnetic metal particles is increased, thereby improving the Q value. In addition, by including a layer composed of Si-containing compounds in the oxide coating, the formation of Fe oxides can also be prevented.

[0128] There is no particular limitation on the method for determining the regions of the first magnetic element 40 and the second magnetic element 42 of the element 2 involved in this embodiment. For example, the determination can also be made by obtaining elemental mapping based on EDS and performing compositional analysis.

[0129] Furthermore, since the first magnetic element 40 and the second magnetic element 42 have different compositions, the regions of the first magnetic element 40 and the second magnetic element 42 can be determined by analyzing the cross-section of the element 2 using SEM or STEM images. Additionally, if the average particle size of the first soft magnetic metal particle is different from the average particle size of the second soft magnetic metal particle, the regions of the first magnetic element 40 and the second magnetic element 42 can be easily determined by analyzing the cross-section of the element 2 using SEM or STEM images.

[0130] In this embodiment, the raw material for the first soft magnetic metal particles is sometimes referred to as "first soft magnetic metal powder," the raw material for the second soft magnetic metal particles is sometimes referred to as "second soft magnetic metal powder," and the raw material for the soft magnetic metal particles is sometimes referred to as "soft magnetic metal powder." That is, the raw material for the first soft magnetic metal particles and the raw material for the second soft magnetic metal particles are sometimes collectively referred to as "soft magnetic metal powder."

[0131] Hereinafter, an example of a method for manufacturing the first soft magnetic metal powder and the second soft magnetic metal powder according to this embodiment will be described.

[0132] In this embodiment, the raw material for the first soft magnetic metal powder can be a single element or an alloy of the constituent elements, such as Fe, Si, or Cr.

[0133] In addition, alloys or elements of the constituent elements can be used as raw materials for the second soft magnetic metal powder, such as Fe-Ni alloys, Fe, Ni, Si, Co, Cr, etc.

[0134] In this embodiment, the soft magnetic metal powder can be obtained using the same method as known methods for manufacturing soft magnetic metal powder. Specifically, the soft magnetic metal powder can be manufactured using gas atomization, water atomization, rotating disk method, etc. Among these, water atomization is preferred from the viewpoint of easily obtaining soft magnetic metal powder with the desired magnetic properties.

[0135] In the water atomization method, raw materials in the form of ingots, blocks, or small balls are prepared, and these raw materials are mixed in a way that results in the desired composition and placed in a crucible located within the water atomization device.

[0136] Next, in an inert atmosphere, a workpiece coil placed outside the crucible is used to heat the crucible to above 1600°C through high-frequency induction, melting and mixing the ingots, blocks or small balls in the crucible to obtain molten metal.

[0137] Molten raw material (molten metal) is supplied as a linear, continuous fluid through a nozzle located at the bottom of the crucible. High-pressure (around 50 MPa) water is blown onto the supplied molten metal to rapidly cool it while it is being dropletized. Through dehydration, drying, and classification, soft magnetic metal powder with the desired average particle size is obtained.

[0138] In this embodiment, for example, each raw material is melted, and the substance containing phosphorus (P) in the melt is micronized by water atomization, thereby producing the soft magnetic metal powder according to this embodiment. Furthermore, if the raw material contains P as an impurity, for example, in an Fe raw material, the total amount of P as an impurity and the amount of added P can be adjusted to produce a soft magnetic metal powder containing a target amount of P. Alternatively, multiple Fe raw materials with different P contents can be used, and a melt with adjusted P content can be micronized by water atomization.

[0139] In this embodiment, a first soft magnetic metal powder, which serves as the raw material powder for the first soft magnetic metal particles, and a second soft magnetic metal powder, which serves as the raw material powder for the second soft magnetic metal particles, are prepared using the method described above.

[0140] Next, for Figure 1 , Figure 1A as well as Figure 1A1 The manufacturing method of the laminated coil 1 shown will be described. First, the obtained first soft magnetic metal powder is slurried together with solvents, binders, and other additives to prepare a first paste. Similarly, the obtained second soft magnetic metal powder is slurried together with solvents, binders, and other additives to prepare a second paste.

[0141] Then, using a second paste, a second green sheet is formed at the shaft end, which, after firing, becomes the second magnetic element 42a1 at the shaft end constituting the shaft end region 2a1.

[0142] Next, on the second green sheet at the shaft end, to become Figure 2a The printed body 100a shown is in the form of a printed conductor 50a1, a first green sheet 400a made of a first paste, and a second green sheet 420a made of a second paste.

[0143] It should be noted that conductor 50a1 and conductor 50a2 (described later) are conductors such as silver (Ag) that become the lead electrodes 5a1 and 5a2 of coil conductor 5 after firing. Furthermore, the first green sheet 400a and the first green sheets 400b to 400h (described later) become the first magnetic material 40 after firing. Moreover, the second green sheet 420a and the second green sheets 420b to 420h (described later) become the second magnetic material 42 after firing. Therefore, in Figure 2aThe process shown is to form the second green sheet 420a in such a way that it becomes the desired inner diameter of the second magnetic element after firing.

[0144] Next, in Figure 2a On the printed body 100a shown, to become Figure 2b The printed body 100b is shown in a manner that prints conductor 50b, a first green sheet 400b made of a first paste, and a second green sheet 420b made of a second paste. That is, in Figure 2b In the printed body shown, conductor 50b is printed in a manner that allows it to connect with conductor 50a1, and the second green sheet 420b is printed in a manner that allows it to connect with conductor 50a1. Figure 2a The second green film 420a shown is printed by overlapping.

[0145] It should be noted that conductor 50b and conductors 50c to 50g, which are described later, are conductors such as silver (Ag) that become coil conductor 5 after firing.

[0146] Next, in Figure 2b On the printed body 100b shown, to become Figure 2c The conductor 50c, the first green sheet 400c made of a first paste, and the second green sheet 420c made of a second paste are printed in the form of the printed body 100c shown. That is, the conductor 50c is printed such that a portion of it (conductor 50c1) can be connected to a portion of it (50b1), and the second green sheet 420c is printed in such a way that it can be connected to it. Figure 2b The second green film 420b shown is printed by overlapping.

[0147] Next, in Figure 2c On the printed body 100c shown, to become Figure 2d The conductor 50d, the first green sheet 400d made of a first paste, and the second green sheet 420d made of a second paste are printed in the form of the printed body 100d shown. That is, the conductor 50d is printed such that a portion of it (conductor 50d1) can be connected to a portion of it (50c2), and the second green sheet 420d is printed in such a way that it can be connected to... Figure 2c The second green film 420c shown is printed by overlapping.

[0148] Next, in Figure 2d On the printed body 100d shown, to become Figure 2e The conductor 50e, the first green sheet 400e made of a first paste, and the second green sheet 420e made of a second paste are printed in the form of the printed body 100e shown. That is, the conductor 50e is printed in a manner that allows it to connect with the conductor 50d, and the second green sheet 420e is printed in a manner that allows it to connect with the conductor 50d. Figure 2d The second green film 420d is printed by overlapping.

[0149] Next, in Figure 2e On the printed body 100e shown, to become Figure 2f The conductor 50f, the first green sheet 400f made of a first paste, and the second green sheet 420f made of a second paste are printed in the form of the printed body 100f shown. That is, the conductor 50f is printed such that a portion of it (conductor 50f1) can be connected to a portion of it (50e1), and the second green sheet 420f is printed in such a way that it can be connected to... Figure 2e The second green film 420e shown is printed by overlapping.

[0150] This will be repeated in the future. Figures 2d to 2f After printing as shown, in Figure 2f On the printed body 100f shown, to become Figure 2g The conductor 50g, a first green sheet 400g made of a first paste, and a second green sheet 420g made of a second paste are printed in the form of a printed body 100g. That is, the conductor 50g is printed such that a portion of it (conductor 50g1) can be connected to a portion of it (50f2), and the second green sheet 420g is printed in such a way that it can be connected to... Figure 2f The second raw film 420f is printed by overlapping.

[0151] Next, in Figure 2g The printed body shown is placed on 100g to become Figure 2h The conductor 50a2, the first green sheet 400h made of the first paste, and the second green sheet 420h made of the second paste are printed in the form of the printed body 100h shown. That is, the conductor 50a2 is printed in a manner that allows it to be connected to the conductor 50g, and the second green sheet 420h is printed in a manner that allows it to be connected to the conductor 50g. Figure 2g The second raw film, 420g, is printed by overlapping.

[0152] It should be noted that, in Figures 2a to 2h In this context, there is no particular restriction on the printing order when printing conductors, the first green film, and the second green film on the same plane.

[0153] Furthermore, in Figure 2h The printed body 100h shown uses a second paste to form a second green sheet at the shaft end, which, after firing, becomes a second magnetic element 42a2 at the shaft end constituting the shaft end region 2a2.

[0154] In the resulting laminate, firstly, Figure 2a The conductor 50a1 of the printed body 100a shown is... Figure 2b The conductor 50b of the printed body 100b shown is in extensive contact and conducts electricity.

[0155] in addition, Figure 2bThe conductor 50b1 of the printed body 100b shown is 50b1 and Figure 2c The conductors 50c1 of the printed body 100c shown are all sandwiched between the imaginary lines J and K, and are conductive through contact.

[0156] also, Figure 2c The printed body 100c shows conductor 50c 50c2 and conductor 50c2. Figure 2d The conductors 50d1 of the printed body 100d shown are all sandwiched between the imaginary lines L and M, and are conductive through contact.

[0157] also, Figure 2d The conductor 50d of the printed body 100d shown is... Figure 2e The conductor 50e of the printed body 100e shown is in extensive contact and conductive.

[0158] and, Figure 2e The conductor 50e of the printed body 100e shown is 50e1 and Figure 2f The conductor 50f1 of the printed body 100f shown is sandwiched between the imaginary line J and the imaginary line K, and therefore is conductive.

[0159] and, Figure 2f The 50f2 of conductor 50f of the printed body 100f shown is... Figure 2g The 100g printed body and 50g conductor shown are both regions sandwiched by imaginary lines L and M, and are conductive through contact.

[0160] and then, Figure 2g The printed body shown has 100g of conductor and 50g of printed body. Figure 2h The conductor 50a2 of the printed body 100h shown is in extensive contact and conduction.

[0161] Here, through having Figure 2d The printed body 100d shown can prevent Figure 2c The 50c1 of the printed body 100c shown is... Figure 2e The 50e1 contact of the printed body 100e shown. As a result, short circuits can be prevented, and a green stack of coil conductor 5 formed in a three-dimensional and helical manner is obtained.

[0162] It should be noted that, Figure 2a The lead-out electrode 5a1 and Figure 2hThe lead-out electrode 5a2 is depicted with the same thickness (Te) as the coil conductor 5 other than the lead-out electrodes 5a1 and 5a2, but the thickness of the lead-out electrodes 5a1 and 5a2 can also be thinner than the thickness (Te) of the coil conductor 5 other than the lead-out electrodes 5a1 and 5a2. By making the thickness of the lead-out electrodes 5a1 and 5a2 thinner than the thickness of the coil conductor 5 other than the lead-out electrodes 5a1 and 5a2, the number of turns per unit volume of the coil can be increased, and the inductance can be improved.

[0163] For example, it can also be in the case of Figure 2a After the printing is overlapped 1-2 times as shown, Figure 2b The printing is overlapped 3 to 8 times as shown. Figures 2c to 2f The printing is overlapped approximately 10 times, thus... Figure 2g After overlapping the printing 3 to 8 times, Figure 2h The printing overlaps 1 to 2 times. As a result, the thickness of the lead electrodes 5a1 and 5a2 can be made thinner than the thickness of the coil conductor 5 other than the lead electrodes 5a1 and 5a2.

[0164] The above describes a method for manufacturing a laminate using a printing method, but a laminate with the above-described structure can also be obtained using a sheet method.

[0165] The resulting laminate is subjected to heat treatment (debinding and sintering processes) to remove the binder, resulting in a sintered body (element) in which the soft magnetic metal particles contained in the soft magnetic metal powder are interconnected and fixed (integrated). The holding temperature in the debinding process (debinding temperature) is not particularly limited, as long as the binder can decompose and be removed as a gas. For example, it can be 300°C or higher and 450°C or lower. Furthermore, the holding time in the debinding process (debinding time) is not particularly limited. For example, it can be 0.5 hours or more and 2.0 hours or less.

[0166] The holding temperature (firing temperature) during the firing process is not particularly limited, as long as it allows the soft magnetic metal particles constituting the soft magnetic metal powder to bond together. It can be above 550℃ and below 850℃. Similarly, the holding time (firing time) during the firing process is also not particularly limited. It can be above 0.5 hours and below 3.0 hours.

[0167] It should be noted that, in this embodiment, it is preferable to adjust the debinding and firing atmosphere.

[0168] Annealing (heat treatment) can also be performed after firing. There are no particular restrictions on the conditions for annealing. For example, it can be carried out at 500–800°C for 0.5–2.0 hours. In addition, there are no particular restrictions on the atmosphere after annealing.

[0169] Next, terminal electrodes 3 are formed on the component. There are no particular restrictions on the method of forming terminal electrodes 3. Generally, the metal (Ag, etc.) that will become terminal electrodes 3 is slurried together with solvents, binders and other additives.

[0170] The laminated coil 1 involved in this embodiment is obtained by the method described above.

[0171] In the laminated coil 1 of this embodiment, the interlayer magnetic element 40a located in the interlayer region 24ba1 of the coil conductor 5 contains first soft magnetic metal particles, and the axial end magnetic elements 42a1 and 42a2 located on the outer side along the axis N of the coil conductor 5 contain second soft magnetic metal particles. The first soft magnetic metal particles have a higher saturation magnetization than the second soft magnetic metal particles. The laminated coil 1 (coil-type electronic component) of this embodiment, with such a structure, has sufficiently high inductance and DC superposition characteristics.

[0172] (Second Implementation)

[0173] The second embodiment will be described below, but aspects not specifically described are the same as those in the first embodiment.

[0174] like Figure 3 As shown, the laminated coil 1 according to this embodiment has a structure in which the coil conductor 5 is embedded in a three-dimensional and double spiral shape. It should be noted that although it is double spiral, the coil conductor 5 is a structure in which the coil conductor 5 is connected as one piece from one lead electrode 5a1 to the other lead electrode 5a2.

[0175] Specifically, in order to Figure 3 The cross-section shown shows a spiral structure formed by connecting the lead-out electrode 5a1 of the first layer, the outer coil conductors 501 and 502 of the second layer, the inner coil conductors 503 and 504 of the second layer, the inner coil conductors 505 and 506 of the third layer, ... the inner coil conductors 521 and 522 of the seventh layer, the outer coil conductors 523 and 524 of the seventh layer, the outer coil conductors 525 and 526 of the eighth layer, the inner coil conductors 527 and 528 of the eighth layer, and the lead-out electrode 5a2 of the ninth layer.

[0176] By making the coil conductor 5 into a double helix shape, the coil becomes more compact, thus increasing the inductance.

[0177] It should be noted that, in Figure 3 In the middle, it is a double spiral with 2 turns for each layer of coil conductor 5, but it is also possible to have 3 or more turns for each layer of coil conductor 5.

[0178] The manufacturing method of the laminated coil 1 involved in this embodiment is not particularly limited. For example, by making the coil conductor 5 three-dimensional and double-helical, in the above-described manner... Figures 2a to 2h By changing the arrangement of the conductor, the first green sheet, and the second green sheet, a stacked body of green blanks is obtained, thereby enabling the stacked coil 1 according to this embodiment to be obtained.

[0179] (Third Implementation)

[0180] The third embodiment will be described below, but aspects not specifically described are the same as those in the first embodiment.

[0181] like Figure 4 As shown, in this embodiment, the axial direction of the coil conductor 5 of the stacked coil 1 is parallel to the Y-axis direction. Figure 4A It is along Figure 4 A general cross-sectional view of the IVA-IVA line. In this embodiment, as... Figure 4A As shown, along the Y-axis, it is divided into an end region 2a and a central region 2b. Additionally, along the Z-axis, it is divided into a coil region 4a, an inner diameter region 4b, and an outer diameter region 4c.

[0182] In the third embodiment, the imaginary line along the outermost coil conductor 5 serves as the boundary, with the outer side being the shaft end regions 2a1 and 2a2, and the inner side being the shaft central region 2b. That is, in the third embodiment, the shaft central region 2b is the area that does not include the lead-out electrodes 5a1 and 5a2.

[0183] (Fourth Implementation)

[0184] The fourth embodiment will be described below, but aspects not specifically described are the same as those in the first embodiment.

[0185] The magnetic material involved in this embodiment is composed of soft magnetic metal particles and resin.

[0186] The components obtained by the methods described in the first to third embodiments have gap spaces in the portion of the magnetic body other than the soft magnetic metal particles. In this embodiment, for example, the gap spaces are filled with resin by impregnating the component with resin.

[0187] By filling the gaps with resin, the strength (especially bending strength) of the laminated coil is increased. Furthermore, the insulation between the soft magnetic metal particles is further improved, making it easier to increase inductance and Q value. Consequently, reliability and heat resistance are improved. Furthermore, the laminated coil is less prone to short circuits.

[0188] There are no particular limitations on the method of resin impregnation. For example, vacuum impregnation can be used. Vacuum impregnation is performed by immersing the aforementioned stacked coil element in resin and controlling the air pressure. The resin penetrates into the interior of the magnetic material by reducing the air pressure. That is, due to the interstitial spaces within the magnetic material, the resin can penetrate into the interior of the magnetic material through these interstitial spaces via the principle of capillary action, particularly into the interlayer regions where the resin is most difficult to penetrate. After impregnating the magnetic material with resin, the resin is cured by heating. The heating conditions vary depending on the type of resin.

[0189] There are no particular restrictions on the type of resin. For example, when using phenolic resin or epoxy resin, the resin can fully penetrate the interlayer spaces within the magnetic substrate (especially the interlayer regions) and easily fill these spaces after curing. Furthermore, it does not easily decompose even when heated, thus exhibiting high heat resistance. In particular, when using phenolic resin or epoxy resin, compared to using silicone resin, the resin more easily and fully penetrates the interlayer spaces within the magnetic substrate (especially the interlayer regions). It should be noted that phenolic resin is preferred because it is inexpensive and easy to handle.

[0190] The resin content in the magnetic body of the final laminated coil is preferably 0.5% by mass or more and 3.0% by mass or less. It should be noted that the resin content can be controlled, for example, by varying the resin solution concentration during impregnation, the impregnation time, and the number of impregnation cycles.

[0191] In this embodiment, electroplating can be performed on the terminal electrodes after resin filling. Since the resin fills the gaps, the plating solution cannot easily penetrate the interior of the magnetic material even when it is immersed in the plating solution. Therefore, no short circuit occurs in the laminated coil even after plating, and the inductance remains high.

[0192] The embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments, and can be modified in various ways within the scope of the present invention.

[0193] For example, such as Figure 1B As shown, the first magnetic element 40 may also be absent. Figure 1A The first magnetic element 40b with an inner diameter is shown. In other words, the second magnetic element 42b with an inner diameter can also constitute the entirety of the central inner diameter region 24bb.

[0194] For example, such as Figure 1C As shown, a second magnetic element 42c with an outer diameter can also be provided on the outer side of the first magnetic element 40c along the central region 2b of the axis.

[0195] For example, such as Figure 1DAs shown, the first magnetic element 40 may also be absent. Figure 1A The inner diameter first magnetic element 40b and the outer diameter first magnetic element 40c are shown. In other words, the entire inner diameter region 24bb at the center of the shaft is composed of the inner diameter second magnetic element 42b, and the entire outer diameter region 24bc at the center of the shaft can also be composed of the outer diameter second magnetic element 42c.

[0196] For example, such as Figure 1E As shown, the entire inner diameter region 24bb at the center of the shaft is composed of the inner diameter first magnetic element 40b, and the entire outer diameter region 24bc at the center of the shaft can also be composed of the outer diameter first magnetic element 40c. In other words, the second magnetic element 42 may not be present. Figure 1A The inner diameter of the second magnetic element 42b and the outer diameter of the second magnetic element 42c are shown.

[0197] like Figures 1B to 1E As shown, there is no particular limitation on the method of changing the configuration of the first magnetic element 40 and the second magnetic element 42. For example, the following method can be given: In the above... Figures 2a to 2h In the printed bodies 100a to 100h shown, the arrangement of the first green sheet and the second green sheet is changed to achieve the desired arrangement of the first magnetic element 40 and the second magnetic element 42.

[0198] In addition, in the above, the ratio of the inner diameter of the second magnetic element and the ratio of the outer diameter of the second magnetic element are calculated by a cross section perpendicular to the axial direction of the coil conductor 5. However, it is also possible to obtain multiple cross sections parallel to the axial direction of the coil conductor 5 and calculate the ratio of the inner diameter of the second magnetic element and the ratio of the outer diameter of the second magnetic element based on them.

[0199] It should be noted that, in this embodiment, a stacked coil is shown as an example of a coil-type electronic component, but transformers, choke coils, and coils are also known as coil-type electronic components. Furthermore, the coil-type electronic component described in this embodiment is suitable for use as an inductor, impedance, etc., in the power supply circuits of various electronic devices such as portable devices.

[0200] [Example]

[0201] The invention will now be described in more detail with reference to the embodiments, but the invention is not limited to these embodiments.

[0202] (Samples in Tables 1 to 3)

[0203] Each raw material was prepared in the manner of becoming a soft magnetic metal powder with the composition described in Table 1 or Table 2. It should be noted that the [mass %] and [ppm] in Table 1 are the contents of each component when the total content of Fe and Si is set to 100% by mass. Similarly, the [mass %] and [ppm] in Table 2 are the contents of each component when the total content of Fe, Ni, Si, Co, Cr, and P is set to 100% by mass.

[0204] Compositional analysis of the obtained soft magnetic metal powders was performed using ICP analysis, and the results confirmed that the composition of each soft magnetic metal powder was as described in Table 1 or Table 2. Therefore, in the examples and comparative examples described later, it is also presumed that the composition of the raw materials used is the same as the composition of the obtained soft magnetic metal powders.

[0205] The saturation magnetization of each soft magnetic metal powder was measured using a vibrating sample magnetometer (VSM-3S-15 manufactured by Toei Kogyo Co., Ltd.) under an external magnetic field of 795.8 kA / m (10 kOe). The results are shown in Tables 1 and 2.

[0206] The first soft magnetic metal powder obtained was used to make a first paste, and the second soft magnetic metal powder was used to make a second paste.

[0207] like Figure 1E As described, the second magnetic element 42 constitutes the shaft end regions 2a1 and 2a2, and the first magnetic element 40 constitutes the interlayer region 24ba1, the shaft center inner diameter region 24bb, and the shaft center outer diameter region 24bc. Figures 2a to 2h In the printed bodies 100a to 100h shown, the arrangement of the first and second green sheets is changed to obtain a green compact laminate with a thickness of 0.8 mm. It should be noted that the conductor is an Ag conductor and the number of turns is 7.5 Ts. Next, the obtained green compact laminate is cut into a 1.6 mm × 0.8 mm shape to obtain a green compact laminated coil.

[0208] Next, the obtained green coils were debonded at 400°C in an inert atmosphere (N2 gas atmosphere). Then, they were fired at 750°C for 1 hour in a reducing atmosphere (a mixture of N2 and H2 gas atmosphere (hydrogen concentration 1.0%)) to obtain the fired body.

[0209] A paste for terminal electrodes is applied to both ends of the obtained sintered body and dried. The body is then sintered at 700°C for 1 hour in an atmosphere with an oxygen partial pressure of 1% to form terminal electrodes 3, thus obtaining a laminated coil sintered product.

[0210] The obtained laminated coil sintered parts are then resin impregnated. Specifically, a mixture of phenolic resin raw materials is vacuum impregnated into the laminated coil sintered parts, and then the resin is cured at 150°C for 2 hours, thereby filling the laminated coil sintered parts with resin. It should be noted that during resin curing, solvents and other substances contained in the raw material mixture evaporate. Subsequently, electroplating is performed to form Ni and Sn plating layers on the terminal electrodes, thereby obtaining laminated coil 1.

[0211] The internal dimensions of the resulting stacked coil are as follows: thickness of coil conductor 5 (Te): 40 μm, thickness of interlayer region 24ba1 (T1): 15 μm.

[0212] The resulting cascaded coils were subjected to compositional analysis, and the average particle size, saturation magnetization, inductance, and DC superposition characteristics were measured.

[0213] <Component Analysis>

[0214] For the stacked coil of Example 1, elemental mapping images of the shaft end regions 2a1 and 2a2, the shaft center inner diameter region 24bb, the interlayer region 24ba1, and the shaft center outer diameter region 24bc were obtained, and compositional analysis was performed. The results confirmed that the regions using the first soft magnetic metal powder contained first soft magnetic metal particles with the same composition as the first soft magnetic metal powder, and the regions using the second soft magnetic metal powder contained second soft magnetic metal particles with the same composition as the second soft magnetic metal powder. Therefore, in the examples and comparative examples described later, it is also presumed that the regions using the first soft magnetic metal powder contained first soft magnetic metal particles with the same composition as the first soft magnetic metal powder, and the regions using the second soft magnetic metal powder contained second soft magnetic metal particles with the same composition as the second soft magnetic metal powder.

[0215] <Average particle size>

[0216] Image analysis of the cross-section of the laminated coil in Example 1 was performed using SEM to determine the equivalent circular diameter of the first and second soft magnetic metal particles, which was then used as the particle size. 400 particle sizes were calculated for both the first and second soft magnetic metal particles, and the average particle size of the first and second soft magnetic metal particles were also determined. The average particle size of the first soft magnetic metal particles is shown in Table 1, and the average particle size of the second soft magnetic metal particles is shown in Table 2.

[0217] <Saturation magnetization (Ms)>

[0218] The first and second magnetic elements of the laminated coil of Example 1 were cut out using laser-based micro-machining. For the first and second soft magnetic metal particles, the saturation magnetization was measured using a vibrating sample magnetometer (VSM-3S-15 manufactured by Toei Kogyo Co., Ltd.) under an external magnetic field of 795.8 kA / m (10 kOe). The results confirmed that the saturation magnetization of the first soft magnetic metal particle was the same as that of the first soft magnetic metal powder, and the saturation magnetization of the second soft magnetic metal particle was the same as that of the second soft magnetic metal powder. Therefore, in the examples and comparative examples described later, it is presumed that the saturation magnetization of the first soft magnetic metal particle is also the same as that of the first soft magnetic metal powder, and the saturation magnetization of the second soft magnetic metal particle is also the same as that of the second soft magnetic metal powder.

[0219] <Measurement of Inductance (L)>

[0220] For the obtained laminated coils, the inductance (L) was measured using an LCR meter (HEWLETT PACKARD: 4285A) at f = 2 MHz and I = 0.1 A. The average value of L for each of the 30 laminated coils was calculated. The results are shown in Table 3. In addition, ΔL / L was calculated as the rate of change of the average value of L relative to the "comparison object of ΔL / L and ΔIdc / Idc" recorded in Table 3. For example, in Example 1, the "comparison object of ΔL / L and ΔIdc / Idc" was "Comparative Example 1", so ΔL / L was calculated by the following formula (1).

[0221] ΔL / L of Example 1 = 100 × {(L of Example 1 - L of Comparative Example 1) / L of Comparative Example 1}……(1)

[0222] <DC superposition characteristic Idc>

[0223] For the obtained laminated coils, the inductance was measured when a DC current was applied. The inductance was measured while the applied DC current was varied from 0 to 3A. The DC current was plotted on the horizontal axis and the inductance on the vertical axis. The current value when the inductance decreased by 30% from the DC current of 0A was calculated as Idc. The average value of Idc for each of the 30 laminated coils was calculated. The results are shown in Table 3. In addition, ΔIdc / Idc was calculated as the rate of change of the average value of Idc relative to the comparison object. For example, in Example 1, the "comparison object of ΔL / L and ΔIdc / Idc" was "Comparative Example 1", so ΔIdc / Idc was calculated by the following formula (2).

[0224] ΔIdc / Idc of Example 1 = 100 × {(Idc of Example 1 - Idc of Comparative Example 1) / Idc of Comparative Example 1}……(2)

[0225] <Judgment>

[0226] Cases where ΔL / L is -30% or more and ΔIdc / Idc is 50% or more are considered acceptable and are recorded as "OK" in Table 3. Conversely, cases where ΔL / L or ΔIdc / Idc is outside the aforementioned ranges are recorded as "NG" in Table 3.

[0227] [Table 1]

[0228] Table 1

[0229]

[0230] [Table 2]

[0231] Table 2

[0232]

[0233] [Table 3]

[0234] Table 3

[0235]

[0236] Based on Tables 1 to 3, it can be confirmed that the interlayer region is composed of the first magnetic element and the axial end region is composed of the second magnetic element. When the saturation magnetization of the first soft magnetic metal particle is higher than that of the second soft magnetic metal particle (Examples 1, 1a, 2, 3, 3a, 3b, 3c, and 3d), it is determined to be OK, and the inductance and DC superposition characteristics are sufficiently high.

[0237] It should be noted that in Comparative Examples 1, 2, 3, 3b, and 3d, the first soft magnetic metal particle and the second soft magnetic metal particle have the same composition, becoming... Figure 5A The structure recorded in the text.

[0238] Furthermore, in Comparative Example 1a, since the saturation magnetization of the first soft magnetic metal particle is lower than that of the second soft magnetic metal particle, it becomes... Figure 5B The structure recorded.

[0239] (Samples in Tables 4 to 6)

[0240] In each of the samples in Tables 4 to 6, the composition of each soft magnetic metal powder was varied in a manner consistent with that described in Table 4 or Table 5. The ratio of the inner diameter second magnetic element to the outer diameter second magnetic element was varied as described in Table 6. Otherwise, stacked coils were obtained in the same manner as in Tables 1 to 3. The average particle size of the soft magnetic metal particles was measured, and L and Idc were measured to calculate (ΔL / L) and (ΔIdc / Idc). The average particle size of the first soft magnetic metal particles is shown in Table 4, and the average particle size of the second soft magnetic metal particles is shown in Table 5. The results for L, Idc, (ΔL / L), and (ΔIdc / Idc) are shown in Table 6.

[0241] In addition, for each sample in Tables 4 to 6, "(ΔL / L) + (ΔIdc / Idc)" was calculated as the balancing measure between "inductance L" and "DC superposition characteristic Idc". The results are shown in Table 6.

[0242] [Table 4]

[0243] Table 4

[0244]

[0245] [Table 5]

[0246] Table 5

[0247]

[0248] [Table 6]

[0249] Table 6

[0250]

[0251] Figure 6 This is a graph relating to Examples 5a and Examples 4-7, where the X-axis represents the percentage of the second magnetic element in the inner diameter portion (%) and the Y-axis represents (ΔL / L) + (ΔIdc / Idc) (%).

[0252] According to Table 6 and Figure 6 It can be confirmed that when the proportion of the second magnetic element in the inner diameter is above 30%, the higher (ΔL / L)+(ΔIdc / Idc) is, the better the balance between inductance and DC superposition characteristics.

[0253] Table 6 confirms that when the proportion of the second magnetic element in the outer diameter is 15% or more, the balance between inductance and DC superposition characteristics is better.

[0254] Furthermore, in Comparative Example 4, since the first soft magnetic metal particle has a lower saturation magnetization than the second soft magnetic metal particle, it becomes... Figure 5CThe structure recorded.

[0255] (Samples in Tables 7 to 9)

[0256] In each sample in Tables 7 to 9, the composition of each soft magnetic metal powder varies in a manner consistent with the composition described in Table 7 or Table 8. Additionally, as... Figure 3 As shown, in Figures 2a to 2h In this process, the arrangement of the conductor, the first green sheet, and the second green sheet was varied to make the coil conductor 5 three-dimensional and double-helical, thus obtaining a green compact laminate. Furthermore, the ratio of the inner diameter of the second magnetic element and the ratio of the outer diameter of the second magnetic element were varied as described in Table 9. In addition to the above, laminated coils were obtained in the same manner as the samples in Tables 1 to 3. The average particle size of the soft magnetic metal particles was measured, and L and Idc were measured to calculate "ΔL / L" and "ΔIdc / Idc". The average particle size of the first soft magnetic metal particles is shown in Table 7, and the average particle size of the second soft magnetic metal particles is shown in Table 8. The results for L, Idc, (ΔL / L), and (ΔIdc / Idc) are shown in Table 9.

[0257] [Table 7]

[0258] Table 7

[0259]

[0260] [Table 8]

[0261] Table 8

[0262]

[0263] [Table 9]

[0264] Table 9

[0265]

[0266] According to Table 9, it can be confirmed that even when the coil conductor 5 is three-dimensional and double-spiral, the interlayer region is composed of the first magnetic element, the shaft end region is composed of the second magnetic element, and the saturation magnetization of the first soft magnetic metal particle is higher than that of the second soft magnetic metal particle (Examples 11 to 15), it is still determined to be OK, and the inductance and DC superposition characteristics are sufficiently high.

[0267] (Samples in Tables 10 to 21)

[0268] In each of the samples listed in Tables 10 to 21, the composition and average particle size of the soft magnetic metal powder varied as described in Tables 10, 11, 13, 14, 16, 17, 19, and 20. Otherwise, the laminated coils were obtained in the same manner as in Example 4. That is, each of the samples in Tables 10 to 21 varied as described in Tables 10 to 20. Figure 1A The structure described in the text is used for production.

[0269] For the obtained laminated coils, the average particle size of the soft magnetic metal particles was measured in the same manner as above, and L and Idc were measured to calculate (ΔL / L) and (ΔIdc / Idc). The average particle size of the first soft magnetic metal particles is shown in Tables 10, 13, 16, and 19, and the average particle size of the second soft magnetic metal particles is shown in Tables 11, 14, 17, and 20. The results for L, Idc, (ΔL / L), and (ΔIdc / Idc) are shown in Tables 12, 15, 18, and 21.

[0270] In addition, for each sample in Tables 10 to 21, the “electroplation elongation inhibition” and “short circuit rate” were determined by the following methods.

[0271] <Electroplation Elongation Inhibition>

[0272] The evaluation of electroplating elongation suppression was performed by observing the appearance of the laminated coils. Case A was defined as no observed electroplating elongation, case B as electroplating elongation less than 50 μm, case C as electroplating elongation greater than 50 μm but less than 400 μm, and case D as electroplating elongation greater than 400 μm. The results are shown in Tables 12, 15, 18, and 21.

[0273] Short circuit count

[0274] Fabricate 30 laminated coils and use an LCR meter to determine the number of short-circuited laminated coils. A result of 0 / 30 is considered good. The results are shown in Tables 12, 15, 18, and 21.

[0275] [Table 10]

[0276] Table 10

[0277]

[0278] [Table 11]

[0279] Table 11

[0280]

[0281] [Table 12]

[0282] Table 12

[0283]

[0284] [Table 13]

[0285] Table 13

[0286]

[0287] [Table 14]

[0288] Table 14

[0289]

[0290] [Table 15]

[0291] Table 15

[0292]

[0293] [Table 16]

[0294] Table 16

[0295]

[0296] [Table 17]

[0297] Table 17

[0298]

[0299] [Table 18]

[0300] Table 18

[0301]

[0302] [Table 19]

[0303] Table 19

[0304]

[0305] [Table 20]

[0306] Table 20

[0307]

[0308] [Table 21]

[0309] Table 21

[0310]

[0311] According to Tables 10 to 12, it can be confirmed that when the average particle size of the first soft magnetic metal particles is 1 to 6 μm (Examples 4, Examples 16 to 18), the balance between inductance and DC superposition characteristics is better, the evaluation of electroplating elongation suppression is higher, and the number of short circuits is less.

[0312] According to Tables 10 to 12, it can be confirmed that when the average particle size of the second soft magnetic metal particles is 1 to 15 μm (Examples 4, Examples 20 to 23), the balance between inductance and DC superposition characteristics is better and the number of short circuits is less.

[0313] According to Tables 13 to 15, it can be confirmed that when the P content of the first soft magnetic metal particles is 10 to 40 ppm (Examples 26 to 28), the evaluation of electroplating elongation suppression is higher and the number of short circuits is less.

[0314] According to Tables 13 to 15, it can be confirmed that when the P content of the second soft magnetic metal particles is 100 to 6000 ppm (Examples 30 to 33), the evaluation of electroplating elongation suppression is higher and the number of short circuits is lower.

[0315] According to Tables 16 to 18, it can be confirmed that when the Ni content of the second soft magnetic metal particles is more than 14.0% by mass and less than 56.0% by mass (Examples 35 to 38), the inductance is large and the balance between inductance and DC superposition characteristics is better.

[0316] According to Tables 19 to 21, it can be confirmed that when the Si content of the first soft magnetic metal particles is 3.5 to 7.5% by mass (Examples 41 to 43), the balance between inductance and DC superposition characteristics is better, the evaluation of electroplating elongation suppression is higher, and the number of short circuits is less.

[0317] According to Tables 19 to 21, it can be confirmed that when the Si content of the second soft magnetic metal particles is 2.0 to 6.0% by mass (Examples 46 and 47), the balance between inductance and DC superposition characteristics is better, the evaluation of electroplating elongation suppression is higher, and the number of short circuits is less.

Claims

1. A coil-type electronic component, wherein, The electronic component includes elements having a magnetic body and a coil conductor. The magnetic element located between layers of adjacent coil conductors in the axial direction of the coil conductors comprises a first soft magnetic metal particle. The magnetic element located on the outer side along the axis comprises a second soft magnetic metal particle. The inner diameter second magnetic element comprises the second soft magnetic metal particle, and the inner diameter second magnetic element is present in at least a portion of the central inner diameter region of the element containing the axis of the coil conductor. The first soft magnetic metal particle has a higher saturation magnetization intensity compared to the second soft magnetic metal particle.

2. The coil-type electronic component according to claim 1, wherein, The first soft magnetic metal particle is an Fe-Si alloy.

3. The coil-type electronic component according to claim 1, wherein, The second soft magnetic metal particle is an Fe-Ni alloy.

4. The coil-type electronic component according to claim 1, wherein, In a cross section perpendicular to the axis of the coil conductor, the area of ​​the inner diameter second magnetic element accounts for more than 30% of the area of ​​the inner diameter region at the center of the axis.

5. The coil-type electronic component according to claim 1, wherein, The average particle size of the first soft magnetic metal particle is 1–6 μm.

6. The coil-type electronic component according to claim 1, wherein, The average particle size of the second soft magnetic metal particle is 1–15 μm.

7. The coil-type electronic component according to claim 1, wherein, The outer diameter second magnetic element comprises the second soft magnetic metal particle, and the outer diameter second magnetic element is present in at least a portion of the axial central outer diameter region of the element located radially outside the coil conductor.

8. The coil-type electronic component according to claim 7, wherein, In a cross section perpendicular to the axis of the coil conductor, the area of ​​the outer diameter second magnetic element accounts for more than 15% of the area of ​​the outer diameter region at the center of the axis.

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