JP2017228768A - Coil component and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coil component in which thinning of a component can be realized while ensuring magnetic characteristics.SOLUTION: A coil component includes a magnetic substance, a conductor, and multiple insulators. The magnetic substance is composed of alloy magnetic particles. The conductor has multiple circulation parts, and is wound around one axis in the magnetic substance. The multiple insulators are placed, respectively, between the multiple circulation parts, while having a round shape including two joining surfaces being joined, respectively, to two circulation parts facing uniaxially and at least partially, and are composed of electrically insulating particles.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a coil component having a magnetic part composed of alloy magnetic particles and a method for manufacturing the same.

  A small coil component or an inductance component called a chip type has been widely used due to the multifunctionality of portable devices and the digitization of automobiles. In particular, since a multilayer inductance component (multilayer inductor) can cope with a reduction in thickness, in recent years, development for a power device in which a large current flows has been advanced.

  In multilayer inductors, magnetic layers and internal conductors are alternately formed, and in many cases, the internal conductors are formed in a plurality of layers. For example, Patent Document 1 discloses a method of manufacturing a multilayer inductor by printing a conductor pattern on a ceramic green sheet containing ferrite or the like, laminating these sheets, and firing them.

JP 7-272935 A

  In recent years, with the progress of miniaturization of electronic devices, further reduction in thickness and size of electronic components to be mounted has been demanded. However, in the structure described in Patent Document 1, the magnetic sheet interposed between the conductor patterns also functions as an electrical insulating layer between the conductor patterns, and in order to ensure a predetermined withstand voltage, the magnetic sheet is used. Since the layer needs to have a predetermined thickness or more (distance between patterns), it is difficult to reduce the thickness of the component. In addition, it is possible to ensure withstand voltage by increasing the content of non-magnetic components such as resin component and glass component in the magnetic layer, but the content of magnetic material is relatively reduced, The deterioration of characteristics is inevitable.

  In view of the circumstances as described above, an object of the present invention is to provide a coil component and a method for manufacturing the same that can realize a thin component while ensuring magnetic properties.

In order to achieve the above object, a coil component according to an aspect of the present invention includes a magnetic body portion, a conductor portion, and a plurality of insulator portions.
The magnetic part is composed of alloy magnetic particles.
The conductor portion has a plurality of winding portions and is wound around one axis inside the magnetic body portion.
The plurality of insulator portions are arranged between the plurality of surrounding portions, respectively, and have a circular shape including two joining surfaces respectively joined to two surrounding portions that are at least partially opposed in the uniaxial direction. And composed of electrically insulating particles.

  In the coil component, since the insulator portion arranged between the plurality of surrounding portions facing in the uniaxial direction is composed of a single layer made of electrically insulating particles, It is possible to reduce the thickness of the entire part while securing the mechanical insulation. Further, in the coil component, since the insulator portion has a circular shape facing at least a part of the circular portion, the alloy magnetic particles in which the inner peripheral side and the outer peripheral region of the circular shape constitute the magnetic portion. It becomes possible to comprise. This makes it possible to ensure the desired magnetic characteristics of the coil component.

The thickness dimension along the uniaxial direction of the plurality of insulator parts may be smaller than the thickness dimension along the uniaxial direction of the plurality of rotating parts.
As a result, the pitch between the rotating portions can be reduced, and the parts can be further reduced in thickness.

The width dimension orthogonal to the uniaxial direction of the plurality of insulator portions may have a size greater than or equal to the width dimension orthogonal to the uniaxial direction of the plurality of rotating portions.
Thereby, the stable electrical insulation between the circulation parts can be ensured.

The electrically insulating particles may include first alloy magnetic particles having an average particle diameter of 1 μm or less.
As a result, the electrical insulation characteristics of the insulator portion can be improved, and the withstand voltage between the surrounding portions can be improved or the pitch between the surrounding portions can be further reduced.

The magnetic part may be composed of second alloy magnetic particles having an average particle size larger than that of the first alloy magnetic particles.
As a result, the magnetic properties of the magnetic part can be improved.

The electrically insulating particles may include silica particles, zirconia particles, or alumina particles having an average particle size of 1 μm or less. The insulator particles may be ferrite particles.
Thereby, the insulation characteristic of an insulator part can be aimed at.

The manufacturing method of the coil component which concerns on one form of this invention is the 1st insulator part of the surrounding shape wound around 1 axis | shaft, The said 1st insulator provided on the said 1st insulator part A conductive first surrounding portion having a first end extending from one end of the portion, and an inner peripheral portion and an outer peripheral portion of each of the first insulator portion and the first surrounding portion, respectively. Forming a first layer having one magnetic material pattern.
A second insulator portion having a circular shape wound around the one axis, and extending from one end of the second insulator portion provided on the second insulator portion, and the first end portion; A conductive second circulating portion having a second end to be connected, and a second magnetic body adjacent to the inner peripheral portion and the outer peripheral portion of each of the second insulator portion and the second peripheral portion. A second layer having a pattern is formed on the first layer.

  As described above, according to the present invention, it is possible to reduce the thickness of components while ensuring magnetic properties.

1 is an overall perspective view of a coil component according to an embodiment of the present invention. It is a disassembled perspective view of the said coil components. It is the sectional view on the AA line in FIG. It is a schematic perspective view which shows the structure of the one magnetic body layer in the said coil components. It is a principal part top view of the surrounding part in the said magnetic body layer. A is a cross-sectional view taken along line AA in FIG. 5, and B is a cross-sectional view taken along line BB in FIG. It is a perspective view explaining the manufacturing method of the said magnetic body layer. It is principal part sectional drawing which shows the modification of a structure of the said coil component. It is a schematic diagram which shows the relationship of the thickness of an insulator part and a circumference part.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 is an overall perspective view of a coil component 10 according to an embodiment of the present invention, FIG. 2 is an exploded perspective view of the coil component 10, and FIG. 3 is a sectional view taken along line AA in FIG. The coil component 10 of the present embodiment is configured as a multilayer inductor for power devices, for example.

[Overall configuration of coil parts]
As shown in FIG. 1, the coil component 10 includes a component main body 11 and a pair of external electrodes 14 and 15. The component main body 11 is formed in a substantially rectangular parallelepiped shape having a width W in the X-axis direction, a length L in the Y-axis direction, and a height H in the Z-axis direction. The pair of external electrodes 14 and 15 are provided on two end faces facing the long side direction (Y-axis direction) of the component main body 11.

  The dimension of each part of the component main body 11 is not specifically limited, In this embodiment, length L is 1-2 mm, width W is 0.5-1 mm, and height H is 0.3-0.6 mm.

  The component main body 11 includes a magnetic body portion 12 having a substantially rectangular parallelepiped shape, and a spiral coil portion 13 (conductor portion) disposed inside the magnetic body portion 12. 2 and 3, the component main body 11 has a structure in which a plurality of magnetic layers MLU, ML1 to ML4, and MLD are stacked and integrated in the height direction (Z-axis direction).

(Magnetic part)
The magnetic layers MLU and MLD respectively constitute upper and lower cover layers of the magnetic body portion 12. The magnetic layers ML1 to ML3 include the surrounding portions C1 to C3 constituting the coil portion 13, the magnetic pattern portions M1 to M3 adjacent to the inner peripheral side and the outer peripheral side of the rotating portions C1 to C3, and the insulator portions IS1 to IS3. Respectively. The magnetic body layer ML4 includes a circulation portion C4 that constitutes the coil portion 13, and a magnetic pattern portion M4 that is adjacent to the inner periphery side and the outer periphery side of the periphery portion C4.

  The magnetic layers MLU and MLD and the magnetic pattern portions M1 to M4 constitute the magnetic portion 12. The magnetic part 12 is composed of alloy magnetic particles.

  As the alloy magnetic particles, alloy particles of Fe (iron), a first component, and a second component are used. The first component is composed of at least one of Cr (chromium) and Al (aluminum), and the second component is composed of at least one of Si (silicon) and Zr (zirconium). In the present embodiment, the first component is Cr and the second component is Si. Therefore, the alloy magnetic particles are composed of FeCrSi alloy particles. The composition of the alloy magnetic particles is typically 1 to 5 wt% for Cr and 3 to 10 wt% for Si. Except for impurities, the rest is Fe and the total is 100 wt%.

The magnetic part 12 has a first oxide film that bonds the alloy magnetic particles to each other. The first oxide film includes the first component, and is Cr ₂ O ₃ in the present embodiment. The magnetic part 12 further has a second oxide film interposed between each alloy magnetic particle and the first oxide film. The second oxide film includes the second component and is SiO ₂ in this embodiment.

(Coil part)
Circulating portions C <b> 1 to C <b> 4 constitute a coil portion 13. As shown in FIG. 2, the orbiting portions C <b> 1 to C <b> 4 have a circling pattern shape that constitutes a part of a coil wound around the Z axis. The circular portions C1 to C4 are electrically connected in the Z-axis direction via the vias V12, V23, and V34, respectively, thereby forming the coil portion 13. In the illustrated example, the number of turns of the coil unit 13 is 3.5. However, the number of turns is not limited to this, and the number of turns can be appropriately set according to specifications, component sizes, and the like.

  Referring to FIG. 2, the turn part C1 has a turn length of (6/8) turn, and a lead end part 13e1 connected to the external electrode 14 and a connection end part Ce1 constituting a part of the via V12. And have. The turning portion C2 has a turn length of (7/8) turns, and includes a connection end Cb2 connected to the connection end Ce1 and a connection end Ce2 constituting the via V23. The turn portion C3 has a turn length of (7/8) turns, and includes a connection end portion Cb3 connected to the connection end portion Ce2 and a connection end portion Ce3 constituting the via V34. The turning portion C4 has a turn length of (6/8) turns, and includes a connection end Cb4 connected to the connection end Ce3 and a lead-out end 13e2 connected to the external electrode 15.

  The coil unit 13 is made of a conductive material. The coil part 13 is comprised by the baking body of an electrically conductive paste, for example, and silver (Ag) paste is used for an electrically conductive paste in this embodiment. The circulating portions C1 to C4 are typically configured with the same width and thickness along the rotating direction.

(Magnetic pattern part)
The magnetic pattern portions M1 to M4 include a first region 121 located on the inner peripheral side of the circulating portions C1 to C4 and a second region 122 positioned on the outer peripheral side of the circulating portions C1 to C4, as a whole. The magnetic layers MLU and MLD are formed in a rectangular shape having the same shape and size (see FIG. 3). The thickness of the magnetic pattern portions M1 to M4 determines the thickness of the magnetic layers ML1 to ML4. Therefore, the magnetic pattern portion M1 has a thickness equal to or greater than the sum of the thickness of the insulator layer IS1 and the thickness of the circulating portion C1.

  The magnetic pattern portions M1 to M4 are composed of FeCrSi-based alloy magnetic particles as described above. The average particle size of the alloy magnetic particles constituting the magnetic pattern portions M1 to M4 may be the same as or different from the average particle size of the alloy magnetic particles constituting the magnetic layers MLU and MLD. The average particle size of the alloy magnetic particles constituting the magnetic pattern portion M1 is, for example, 1 μm or more and 5 μm or less.

(Insulator part)
The insulator parts IS1 to IS3 are arranged between the circumference parts C1 to C4, respectively, and have a round shape including two joint surfaces respectively joined to two round parts that are at least partially opposed in the Z-axis direction. . That is, in this embodiment, each of the insulator portions IS1 to IS3 has a circular pattern shape including the opposing regions of the respective circular portions C1 to C4, and the respective opposing surfaces of the two circular portions facing each other in the Z-axis direction. It is comprised by the single layer which has two joining surface Sa and Sb joined to (refer FIG. 3).

The insulator portions IS1 to IS3 constitute a part of the magnetic layers ML1 to ML3. As an example, the structure of the insulator part IS1 provided in the magnetic layer ML1 is shown in FIGS.
FIG. 4 is a perspective view of the magnetic layer ML1. 5 is a plan view of a principal part of the connection end portion Ce1 of the rotating portion C1 in the magnetic layer ML1, FIG. 6A is a cross-sectional view taken along line AA in FIG. 4, and FIG. 6B is a cross-sectional view taken along line BB in FIG. It is.

  Each of the insulators IS1 to IS3 has a width dimension that is equal to or greater than the width dimension in the circumferential direction than the circumferential parts C1 to C4, and in this embodiment, the width is larger than the width dimension Wc of the circumferential parts C1 to C4. It has the dimension Ws (refer FIG. 3, FIG. 5). This prevents a short circuit between the surrounding portions due to the conductive material (conductor paste constituting the surrounding portion) that has permeated between the alloy magnetic particles constituting the magnetic body portion 12 adjacent to the surrounding portions C1 to C4. A desired withstand voltage can be secured.

  The ratio of the width dimension Wc of the circular portion C1 and the width dimension Ws of the insulator portion IS1 is not particularly limited, and is, for example, 10 μm or more and 80 μm or less in terms of (Ws−Wc).

  As shown in FIG. 8, the insulator portions IS1 to IS3 may be configured with the same width dimension as that of the circumferential portions C1 to C4. In this case, compared with the configuration of FIG. 3, there is a concern that the magnetic characteristics (inductance characteristics) of the entire coil component may be decreased due to a decrease in the withstand voltage characteristics between the surrounding portions sandwiching the insulator portions IS1 to IS3. The direct current superimposition characteristics of parts can be enhanced. That is, the width dimensions of the insulator portions IS1 to IS3 can be adjusted according to the specifications of the coil components.

  The thickness of the insulator portions IS1 to IS3 (thickness dimension along the Z-axis direction, hereinafter the same) is not particularly limited, and is set to an appropriate thickness that can ensure a predetermined withstand voltage between the surrounding portions. The thickness of the insulator portions IS1 to IS3 may be equal to or greater than the thickness of the circulating portions C1 to C4, or may be smaller than the thickness of the circulating portions C1 to C4.

  In the present embodiment, the insulator portions IS1 to IS3 are formed with a smaller thickness than the circulating portions C1 to C4. Since the insulator parts IS1 to IS3 are formed with a thickness smaller than the circulation parts C1 to C4, the component main body 11 can be made thinner. Or since the thickness of the surrounding parts C1-C4 can be enlarged, resistance reduction of the surrounding parts C1-C4 can be achieved.

  In FIG. 6A, the upper surface of the insulator portion IS1 constitutes a first bonding surface Sa bonded to the lower surface of the rotating portion C1, and the lower surface of the insulator portion IS1 is the upper surface of the magnetic layer ML2 (of the magnetic pattern portion M2). A second bonding surface Sb bonded to the upper surface) is formed. The first joint surface Sa is joined to all regions except the one end portion Ce1 of the circumferential portion C1, and electrical connection between the one end portion Ce1 of the circumferential portion C1 and the one end portion Cb2 of the circumferential portion C2 is ensured.

  Insulator parts IS1 to IS3 are made of electrically insulating particles. The electrically insulating particles constituting the magnetic parts IS1 to IS3 are not particularly limited, and may be alloy magnetic particles or oxide ceramic particles such as silica particles, zirconia particles, alumina particles, and ferrite particles. The electrically insulating particles are various alloy magnetic particles that can be combined with each other by heat treatment to form an insulator layer, and an insulator from the beginning, and the particles are bonded by heat treatment, Oxide ceramics particles such as ferrite particles, which fuse particles together to form a layer of insulators by fusing the grain boundaries together, and are insulative from the beginning and remain in powder form even after heat treatment And oxide ceramic particles such as silica particles, zirconia particles, and alumina particles.

  As described above, the electrically insulating particles include those in which the particles are bonded by heat treatment. That is, the insulator parts IS1 to IS3 are not limited to the form constituted by the insulator particles themselves, but also include the form constituted by a combination of the insulator particles. In particular, in this embodiment, particles that hardly undergo shrinkage or volume change due to heat treatment are used. When the insulator parts IS1 to IS3 composed of such particles are observed by SEM (Scanning Electron Microscopy), individual particles, a state in which the particles are bonded, a state in which the particles are sintered, etc. are formed between the particles. Observed at the same time as the generated voids. The voids may be filled with a binder or other material.

  It is desirable that the insulator portions IS1 to IS3 do not change in volume during the heat treatment. The insulator parts IS1 to IS3 can be formed as a thin layer while ensuring insulation between the surrounding parts C1 to C4 by ensuring that the insulating parts IS1 to IS3 have high insulation even by heat treatment and do not change in volume. For example, when the insulator parts IS1 to IS3 are made of a material that causes both of the shape changes of shrinkage due to heat treatment, for example, low-melting glass, in order to ensure insulation between the surrounding parts C1 to C4, insulation The body parts IS1 to IS3 cannot be formed as a thin layer, and it is impossible to reduce the thickness of the component while ensuring the magnetic characteristics.

  As the alloy magnetic particles (first alloy magnetic particles) constituting the insulator parts IS1 to IS3, the alloy magnetic particles (second alloy magnetic particles) constituting the magnetic pattern parts M1 to M4 (magnetic body part 12) and Alloy magnetic particles having the same composition, that is, FeCrSi-based alloy magnetic particles can be used.

  The average particle size of the alloy magnetic particles constituting the insulator portions IS1 to IS3 may be the same as or different from the average particle size of the alloy magnetic particles constituting the magnetic pattern portions M1 to M4. Typically, alloy magnetic particles having an average particle size equal to or smaller than (for example, 3 μm or less) the average particle size of the alloy magnetic particles constituting the magnetic pattern portion M1 are used as the alloy magnetic particles constituting the insulator portion IS1. It is also possible to use alloy magnetic particles having an average particle diameter of 1 μm or less.

  The thickness of the insulator portions IS1 to IS3 made of alloy magnetic particles is, for example, 3 μm or more. In this case, when the insulator portions IS1 to IS3 are composed of alloy magnetic particles having an average particle diameter of 1 μm or less, three or more alloy magnetic particles are arranged in the thickness direction. Since the specific surface area increases as the average particle size decreases, the contact area between the particle surface and the oxide film also increases, so that the desired insulating properties can be secured stably.

  In the case where oxide ceramic particles such as silica particles, zirconia particles, alumina particles, and ferrite particles are used as the electrically insulating particles constituting the insulator portions IS1 to IS3, the insulating properties of the insulator portions IS1 to IS3 are further improved. Can do. Thereby, the dielectric breakdown due to the potential difference between the conductors of the circulating portions C1 to C4 can be prevented, and the thickness of the insulator portions IS1 to IS3 can be further reduced. In addition, since this type of ceramic particles can easily obtain particles having an average particle diameter of 1 μm or less, it is possible to stably produce insulator portions IS1 to IS3 having a thickness of 2 μm or less, for example. .

  On the other hand, since the alloy magnetic particles and the ferrite particles are made of a magnetic material, even if the insulator parts IS1 to IS3 have a relatively large thickness or width dimension, they are used as the electrically insulating particles. A decrease in magnetic properties is suppressed. Therefore, as shown in FIG. 3, even when the width dimension Ws of the insulators IS1 to IS3 is larger than the width dimension of the circuit parts C1 to C4, the coil component is ensured while ensuring the insulation between the circuit parts C1 to C4. It is possible to suppress the deterioration of the magnetic characteristics.

[Manufacturing method of coil parts]
As described above, the component main body 11 is manufactured by laminating the magnetic layers MLU, ML1 to ML4, and MLD in the thickness direction. The magnetic layer MLU and the magnetic layer MLD constituting the upper and lower cover layers are each composed of a laminate of a predetermined number of magnetic sheets. On the other hand, the magnetic layers ML1 to ML4 constituting the coil unit 13 are individually manufactured by a printing method or the like, for example.

  7A to 7C are perspective views illustrating a method for manufacturing the magnetic layer ML1.

  When producing the magnetic layer ML1, a support sheet S made of a resin sheet such as PET (polyethylene terephthalate) is used as shown in FIG. 7A. Then, on one surface of the support sheet S, the insulator portion IS1, the circulating portion C1, and the magnetic pattern portion M1 are sequentially formed by using, for example, a screen printing method using an insulator paste, a conductor paste, and a magnetic paste prepared in advance. Thus, the magnetic layer ML1 is manufactured.

  Insulator part IS1 is formed in the formation area of circumference part C1 on support sheet S by the circumference shape corresponding to circumference part C1. At this time, the insulator part IS1 has a wider shape than the surrounding part C1, and is provided in all regions except the one end part Ce1 constituting the via (V12) of the surrounding part C1 (FIG. 7A).

  The circular portion C1 is formed in a predetermined circular shape on the insulator portion IS1. At this time, the circulating portion C1 is formed in the central portion of the insulator portion IS1 with a width dimension (Wc) smaller than the width dimension (Ws) (see FIG. 5). Further, the one end portion Ce1 of the circulating portion C1 is formed on the support sheet S by extending a predetermined length so as to straddle the end portion of the insulator portion IS1 (see FIG. 6B).

  9A to 9C are schematic diagrams illustrating the relationship between the thickness of the insulator part IS1 and the circulating part C1. Here, FIG. 9A shows an example in which the insulator part IS1 is formed with the same thickness as the circulating part C1, and FIGS. 9B and 9C show an example in which the insulator part IS1 is formed thinner than the circulating part C1. ing. 9A to 9C show an example in which the insulator part IS1 is formed with a larger width dimension than the circulating part C1. The difference in width between the insulator part IS1 and the circumference part C1 is not particularly limited, but as shown in the figure, the insulator part IS1 may be configured to protrude from the side surface of the circumference part C1 by an amount corresponding to the thickness. In this case, the difference in the width between the insulator part IS1 and the circulating part C1 is set smaller as the thickness of the insulator part IS1 is smaller.

  When the thickness of the insulator part IS1 is reduced, it is preferable that the average particle diameter of the particles constituting the insulator part IS1 is smaller. This is because if the average particle size is large, a thickness is required, and the amount of protrusion from the side surface of the circulating portion C1 is increased accordingly. In addition, since the uniformity of the thickness is obtained as the average particle size is smaller, the insulator part IS1 can be stably formed.

  The magnetic pattern portion M1 is formed on the support sheet S so as to be adjacent to the inner peripheral portion and the outer peripheral portion of each of the insulator portion IS1 and the rotating portion C1. At this time, the magnetic pattern portion M1 covers both side portions of the insulator portion IS1 that are not covered by the rotating portion C1 and a predetermined tip region of the end portion Ce1 of the rotating portion C1.

  For ease of explanation, only a single magnetic layer ML1 is shown in FIGS. 7A to 7C, but in reality, the support sheet S is large enough to take a large number of magnetic layers ML1 in a plane. The plurality of magnetic layers ML1 are formed on the same support sheet S through the above steps.

  The magnetic layers ML2 to ML4 are also produced by the same method as described above. In addition, about magnetic body layer ML4, since formation of an insulator layer is unnecessary, only the rotation part C4 and the magnetic pattern part M4 are produced (refer FIG. 2).

  The magnetic layers MLU, MLD, ML1 to ML4 are laminated as shown in FIG. 2 and then integrated by thermocompression bonding. At this time, the support sheet S is sequentially peeled and removed when the magnetic layers ML1 to ML4 are stacked. As a result, the end portions Ce1 to Ce4 of the surrounding portions C1 to C4 adjacent in the stacking direction are connected to form vias V12, V23, and V34 (see FIG. 2).

  The laminate of the magnetic layers is cut into a component body size using a cutting machine (not shown) such as a dicing machine or a laser processing machine. The obtained component chip is heat-treated in an oxidizing atmosphere such as air using a heat treatment machine (not shown) such as a firing furnace. This heat treatment includes a degreasing process and an oxide film forming process. The degreasing process is performed at about 300 ° C. for about 1 hour, and the oxide film forming process is performed at about 700 ° C. for about 2 hours. Is done.

  In the oxide film forming process subsequent to the degreasing process, the FeCrSi alloy particles in the magnetic body before the heat treatment are densely formed to produce the magnetic body portion 12 (see FIGS. 1 and 2), and at the same time, the surface of each of the FeCrSi alloy particles. Then, an oxide film of the particles is formed. Moreover, the Ag particle group in the coil part before the heat treatment is sintered to produce the coil part 13 (see FIGS. 1 and 2), and the magnetic pattern parts M1 to M4 of the magnetic layers ML1 to ML4 are integrated. Thus, a common magnetic pattern portion M (see FIG. 3) is produced. Thereby, the component main body 11 is produced.

  Subsequently, using a coating machine (not shown) such as a dip coating machine or a roller coating machine, a conductor paste prepared in advance is applied to both ends in the length direction of the component body 11, and this is applied to a heat treatment machine such as a firing furnace. (Not shown), a baking process is performed at a temperature of about 650 ° C. for about 20 minutes, the solvent and binder are eliminated and the Ag particles are sintered by the baking process. 1 (see FIG. 2). Finally, plating is performed. The plating is performed by general electroplating, and a metal film of Ni and Sn is attached to the external electrodes 14 and 15 formed by previously sintering the Ag particle group. Thereby, the coil component 10 is produced.

  The magnetic layers ML1 to ML4 may be sequentially stacked by a buildup method. In this case, the magnetic layer ML4 is first formed on the support sheet, and the magnetic layer ML3, the magnetic layer ML2, and the magnetic layer ML1 are sequentially formed thereon. As the support sheet S of the magnetic layer ML4, the magnetic layer MLD constituting the lower cover layer may be used.

  In the coil component 10 of the present embodiment configured as described above, the insulator portions IS1 to IS3 disposed between the plurality of circulating portions C1 to C4 facing each other in the Z-axis direction are made of electrically insulating particles. Since it is composed of a single layer, it is possible to reduce the thickness of the entire component while ensuring electrical insulation between the circulating portions C1 to C4.

  Further, in the coil component 10 of the present embodiment, since the insulator portions IS1 to IS3 have a circular shape facing at least a part of the circular portions C1 to C4, the inner peripheral side and the outer peripheral region of the circular shape are provided. It becomes possible to comprise the alloy magnetic particles constituting the magnetic body part 12 (magnetic pattern parts M1 to M4). Thereby, the desired magnetic characteristics of the coil component 10 can be ensured.

  According to the present embodiment, since the thickness dimensions of the insulator parts IS1 to IS3 are smaller than the thickness dimensions of the circulating parts C1 to C4, it becomes possible to reduce the pitch between the circulating parts C1 to C4 and further reduce the thickness of the parts. Can be achieved.

  Further, by using alloy magnetic particles having an average particle size of 1 μm or less as the electrically insulating particles constituting the insulator portions IS1 to IS3, the electrical insulation characteristics of the insulator portions IS1 to IS3 are improved, and the circulation portions C1 to C1 The insulation withstand voltage between C4 can be improved, or the pitch between the surrounding portions C1 to C4 can be further reduced, and as a result, the parts can be made thinner.

  Furthermore, since the magnetic body part 12 is comprised by the alloy magnetic particle whose average particle diameter is larger than the alloy magnetic particle which comprises the insulator parts IS1-IS3, the improvement of the magnetic characteristic of the magnetic body part 12 can be aimed at. . Alternatively, by improving the magnetic characteristics of the magnetic body portion 12, the thickness of the magnetic body layers MLU and MLD constituting the upper and lower cover layers can be reduced to further reduce the thickness of the component.

  Next, examples of the present invention will be described.

Example 1
The coil component shown in FIG. 3 (or FIG. 8) was produced under the following conditions.
Magnetic part size: length 1000 μm, width 500 μm, height 499 μm
Alloy magnetic particles: FeSiCr (3.5Si4.5Cr), average particle size 3 μm
・ Conductor part (circumference part)
Number of turns: 13.5 (16 layers)
Thickness: 9.0μm
Width (Wc): 140 μm
-Insulator part Constituent particle: Alloy magnetic particle (FeSiCr (3.5Si4.5Cr)), average particle size 3 μm
Thickness 13μm
Width (Ws): 218 μm
Width difference (Ws-Wc): 78 μm

  The average particle diameter is an average particle diameter (median diameter) when viewed as a volume-based particle diameter. For example, the cumulative percentage of the particle size distribution measured by the laser diffraction particle size distribution measurement method is 50% (D50 ).

  Subsequently, the withstand voltage of the produced coil parts was measured using an impulse tester. As measurement conditions, the pulse width was set to 1.5 μsec, and a voltage that could clear all 20 samples was evaluated. As a result, it was 50V.

(Example 2)
The height of the magnetic part is 472 μm, the average particle diameter of the alloy magnetic particles is 2 μm, the thickness of the conductor part is 12 μm, the average particle diameter of the constituent particles of the insulator part is 2 μm, the thickness is 8 μm, and the width (Ws) is A coil component was fabricated under the same conditions as in Example 1 except that the thickness was 185 μm (width difference: 45 μm). When the withstand voltage of the produced coil component was measured under the same conditions as in Example 1, it was 50V.

(Example 3)
The height of the magnetic part is 474 μm, the average particle diameter of the alloy magnetic particles is 1.5 μm, the thickness of the conductor part is 14 μm, the average particle diameter of the constituent particles of the insulator part is 1.5 μm, the thickness is 6 μm, and the width A coil component was manufactured under the same conditions as in Example 1 except that the thickness was set to 170 μm (width difference: 30 μm). When the withstand voltage of the produced coil component was measured under the same conditions as in Example 1, it was 50V.

Example 4
The height of the magnetic part is 429 μm, the average particle diameter of the alloy magnetic particles is 1 μm, the thickness of the conductor part is 14 μm, the average particle diameter of the constituent particles of the insulator part is 1 μm, the thickness is 3 μm, and the width is 155 μm (width) A coil component was manufactured under the same conditions as in Example 1 except that the difference was 15 μm. When the withstand voltage of the produced coil component was measured under the same conditions as in Example 1, it was 50V.

(Example 5)
The height of the magnetic part is 405 μm, the average particle diameter of the alloy magnetic particles is 5 μm, the thickness of the conductor part is 14 μm, the average particle diameter of the constituent particles of the insulator part is 1 μm, the thickness is 3 μm, and the width is 155 μm (width) A coil component was manufactured under the same conditions as in Example 1 except that the difference was 15 μm. When the withstand voltage of the produced coil component was measured under the same conditions as in Example 1, it was 50V.

(Example 6)
The height of the magnetic part is 382.5 μm, the average particle diameter of the alloy magnetic particles is 5 μm, the thickness of the conductor part is 14 μm, the constituent particles of the insulator part are silica particles (average particle diameter 0.5 μm), and the thickness is A coil component was manufactured under the same conditions as in Example 1 except that the width was 1.5 μm and the width was 150 μm (width difference 10 μm). When the withstand voltage of the produced coil component was measured under the same conditions as in Example 1, it was 50V.

(Example 7)
The height of the magnetic part is 382.5 μm, the average particle diameter of the alloy magnetic particles is 5 μm, the thickness of the conductor part is 14 μm, the constituent particles of the insulator part are silica particles (average particle diameter 0.05 μm), and the thickness is A coil component was manufactured under the same conditions as in Example 1 except that the width was set to 1.5 μm and the width was set to 170 μm (ratio 21%). When the withstand voltage of the produced coil component was measured under the same conditions as in Example 1, it was 50V.

(Example 8)
The height of the magnetic part is 494 μm, the average particle diameter of the alloy magnetic particles is 5 μm, the thickness of the conductor part is 4 μm, the average particle diameter of the constituent particles of the insulator part is 5 μm, the thickness is 18 μm, and the width is 140 μm (width) A coil component was manufactured under the same conditions as in Example 1 except that the difference was 0). When the withstand voltage of the manufactured coil component was measured under the same conditions as in Example 1, it was 25V.

  The production conditions and withstand voltages of Examples 1 to 8 are summarized in Table 1.

  As shown in Table 1, it was confirmed that a withstand voltage of about 25 V or more was obtained for Examples 1 to 8. In particular, in Examples 1 to 7 in which the average particle diameter of the constituent particles of the insulator part is 3 μm or less, the thickness of the insulator part is small compared to Example 8 in which the average particle diameter is 5 μm. Regardless, it was confirmed that the withstand voltage was high. This is presumably because the smaller the average particle size of the constituent particles of the insulator part, the higher the smoothness and the more uniform the thickness.

  Furthermore, since the thickness of the conductor part of Examples 1-7 is larger than that of Example 8, a coil component having a lower resistance than that of Example 8 can be produced. When the ratio of those of Examples 1 to 7 with respect to the DC resistance of the conductor portion of Example 8 was measured, the results shown in Table 1 were obtained.

As mentioned above, although embodiment of this invention was described, this invention is not limited only to the above-mentioned embodiment, Of course, a various change can be added.

  For example, in the above embodiment, the external electrodes 14 and 15 are provided on the two end faces facing the long side direction of the component main body 11, but the present invention is not limited to this, and two external electrodes facing the short side direction of the component main body 11 are provided. It may be provided on the side surface.

DESCRIPTION OF SYMBOLS 10 ... Coil component 11 ... Component main body 12 ... Magnetic body part 13 ... Coil part 14, 15 ... External electrode C1-C4 ... Circulation part IS1-IS3 ... Insulator part M1-M4 ... Magnetic pattern part ML1-ML4, MLU, MLD ... Magnetic layer

Claims (8)

A magnetic body composed of alloy magnetic particles;
A conductor portion having a plurality of surrounding portions and wound around one axis inside the magnetic body portion;
Each of the plurality of circular portions is arranged between the plurality of circular portions, and each of the circular shapes includes two joint surfaces that are respectively joined to the two circular portions that are at least partially opposed to each other in the uniaxial direction. A coil component comprising a plurality of insulator portions. The coil component according to claim 1,
The thickness dimension along the uniaxial direction of the plurality of insulator portions is smaller than the thickness dimension along the uniaxial direction of the plurality of rotating portions. The coil component according to claim 1 or 2,
The coil part having a width dimension orthogonal to the uniaxial direction of the plurality of insulator parts is equal to or greater than a width dimension orthogonal to the uniaxial direction of the plurality of winding parts. The coil component according to any one of claims 1 to 3,
The electrical insulating particles include first alloy magnetic particles having an average particle diameter of 1 μm or less. The coil component according to claim 4,
The said magnetic body part is comprised by the 2nd alloy magnetic particle whose average particle diameter is larger than the said 1st alloy magnetic particle. The coil component according to any one of claims 1 to 3,
The coil component includes silica particles, zirconia particles, or alumina particles having an average particle diameter of 1 μm or less. The coil component according to any one of claims 1 to 3,
The electrically insulating particles include a ferrite particle. A first insulator portion having a circular shape wound around one axis, and a first end portion provided on the first insulator portion and extending from one end of the first insulator portion. Forming a first layer having a conductive first surrounding part and a first magnetic pattern adjacent to the inner and outer circumferences of each of the first insulator part and the first surrounding part; And
A second insulator portion having a circular shape wound around the one axis; and the first end portion provided on the second insulator portion and extending from one end of the second insulator portion; A conductive second circumferential portion having a second end to be connected, and a second magnetic body adjacent to the inner circumferential portion and the outer circumferential portion of each of the second insulator portion and the second circumferential portion. A method of manufacturing a coil component, wherein a second layer having a pattern is formed on the first layer.

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