Multilayer coil components

Abstract

To provide a multilayer coil component in which occurrence of poor appearance caused by depression in an exposed portion of a lead conductor is restrained.SOLUTION: A multilayer coil component 1 includes an element body 10A formed by laminating a plurality of insulating layers P1 to P15, Px in a lamination direction L, a coil 30A provided inside the element body, and an external electrode that is provided on the surface of the element body and electrically connected to a coil. The coil is electrically connected to a plurality of coil conductors Q1 to Q15 laminated in the lamination direction through via conductors penetrating through the insulating layers in the lamination direction. The plurality of coil conductors includes laminated parts Ea1, Fa1 consisting of a plurality of adjacent coil conductors, and the coil is electrically connected to the external electrode through a plurality of lead-out conductors 41 to 44. The lead-out conductor 41 includes lead-out via conductors Saa1, Saax penetrating through the insulating layers in the lamination direction, and a diameter of the lead-out via conductor is 100 μm or less.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a multilayer coil component. [Background technology]

[0002] Patent Document 1 describes a rectangular parallelepiped laminate formed by stacking a plurality of insulator layers in a stacking direction, the laminate having a first side surface formed by connecting the outer edges of the plurality of insulator layers, a coil provided on the laminate and formed by connecting a plurality of coil conductors by via-hole conductors that pass through the insulator layers, the coil having a spiral shape that advances in the stacking direction while winding around, a first external electrode provided on at least the first side surface, and a second external electrode provided on the other side of the first external electrode in the stacking direction and also provided on at least the first side surface, and the coil has m coil conductors that are arranged in the stacking direction, and at least a portion of the m coil conductors that are arranged in the stacking direction are arranged in parallel. An electronic component is disclosed, characterized in that it includes a first parallel section configured by connecting in a row, and a second parallel section configured by connecting in parallel at least a portion of n coil conductors arranged in the stacking direction, where m and n are natural numbers, n is greater than m, and the proportion of the number of the first parallel sections to the total number of the first parallel sections and the second parallel sections in a first region that overlaps with the first external electrode when viewed in a plane from the normal direction of the first side surface is higher than the proportion of the number of the first parallel sections to the total number of the first parallel sections and the second parallel sections in a second region that does not overlap with the first external electrode and the second external electrode when viewed in a plane from the normal direction of the first side surface. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2015 / 022889 Summary of the Invention [Problem to be solved by the invention]

[0004] Figure 2 of Patent Document 1 discloses an electronic component in which two or three coil conductors are connected in parallel. Patent Document 1 also describes that the electronic component shown in Figure 2 connects the coil and external electrodes via an extraction conductor made up of multiple via-hole conductors that penetrate an insulator layer. However, the inventors' investigations have revealed that the electronic component shown in Figure 2 of Patent Document 1 has the following problems.

[0005] In the electronic component shown in Figure 2 of Patent Document 1, two or three coil conductors are connected in parallel, which is thought to increase the cross-sectional area of ​​the coil in the direction along the current path of the coil, i.e., perpendicular to the direction in which the coil conductor extends. Therefore, in the electronic component shown in Figure 2 of Patent Document 1, the direct current resistance (Rdc) of the coil is low, which is thought to enable a large current to flow through the coil.

[0006] In the electronic component shown in FIG. 2 of Patent Document 1, when a large current is passed through the coil, a large current also flows through the lead conductor. To facilitate the flow of a large current through the lead conductor, for example, increasing the cross-sectional area of ​​the lead conductor perpendicular to its extension direction can be considered to reduce the DC resistance of the lead conductor. However, if the cross-sectional area of ​​the via-hole conductor constituting the lead conductor is increased to increase the cross-sectional area of ​​the lead conductor, the via-hole conductor is more susceptible to thermal shrinkage than the surrounding insulator layers during the process of fabricating the lead conductor. As a result, the exposed portion of the lead conductor exposed on the surface of the laminate is recessed relative to the surrounding insulator layers, resulting in a problem of poor appearance of the electronic component.

[0007] The present invention has been made to solve the above problems, and has an object to provide a multilayer coil component in which the occurrence of poor appearance due to depressions in exposed portions of lead conductors is suppressed. [Means for solving the problem]

[0008] The laminated coil component of the present invention comprises an element body formed by laminating a plurality of insulating layers in a lamination direction, a coil provided inside the element body, and an external electrode provided on a surface of the element body and electrically connected to the coil, wherein the coil is formed by a plurality of coil conductors laminated in the lamination direction and electrically connected to each other via via conductors that penetrate the insulating layers in the lamination direction, the plurality of coil conductors laminated in the lamination direction include a laminated portion formed of a plurality of adjacent coil conductors, the laminated portion having parallel sections in which all of the coil conductors constituting the laminated portion overlap when viewed from the lamination direction, the parallel sections being connected in parallel by the via conductors, the coil is electrically connected to the same external electrode via a plurality of lead conductors, each of the lead conductors includes a lead via conductor that penetrates the insulating layers in the lamination direction, and the lead via conductor has a diameter of 100 μm or less. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a multilayer coil component in which the occurrence of poor appearance due to depressions in exposed portions of lead conductors is suppressed. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic perspective view showing an example of a multilayer coil component according to the present invention. [Figure 2] FIG. 2 is a schematic perspective view showing an example of an exploded state of the multilayer coil component (excluding the external electrodes) shown in FIG. [Figure 3] FIG. 3 is a schematic plan view showing an example of an exploded state of the multilayer coil component shown in FIG. 1 (excluding the external electrodes). [Figure 4] FIG. 4 is an enlarged schematic cross-sectional view showing an example of the vicinity of the first end face of the element body in the multilayer coil component shown in FIG. 1, as viewed in the height direction. [Figure 5] FIG. 5 is an enlarged schematic cross-sectional view showing an example of the vicinity of the second end face of the element body in the multilayer coil component shown in FIG. 1, as viewed in the height direction. [Figure 6] FIG. 6 is an enlarged cross-sectional schematic view showing an example of three coil conductors constituting the parallel running section in the multilayer coil component shown in FIGS. 2 and 3, as viewed in the height direction. DETAILED DESCRIPTION OF THE INVENTION

[0011] The multilayer coil component of the present invention will be described below. Note that the present invention is not limited to the following configurations and may be modified as appropriate without departing from the spirit of the present invention. Furthermore, a combination of multiple individual preferred configurations described below also constitutes the present invention.

[0012] The drawings shown below are schematic diagrams, and the dimensions, aspect ratio, scale, etc. may differ from those of the actual product.

[0013] The laminated coil component of the present invention comprises an element body formed by laminating a plurality of insulating layers in a lamination direction, a coil provided inside the element body, and an external electrode provided on a surface of the element body and electrically connected to the coil, wherein the coil is formed by a plurality of coil conductors laminated in the lamination direction and electrically connected to each other via via conductors that penetrate the insulating layers in the lamination direction, the plurality of coil conductors laminated in the lamination direction include a laminated portion formed of a plurality of adjacent coil conductors, the laminated portion having parallel sections in which all of the coil conductors constituting the laminated portion overlap when viewed from the lamination direction, the parallel sections being connected in parallel by the via conductors, the coil is electrically connected to the same external electrode via a plurality of lead conductors, each of the lead conductors includes a lead via conductor that penetrates the insulating layers in the lamination direction, and the lead via conductor has a diameter of 100 μm or less.

[0014] FIG. 1 is a schematic perspective view showing an example of a multilayer coil component according to the present invention.

[0015] The multilayer coil component 1 shown in Fig. 1 has an element body 10A, a first external electrode 21, and a second external electrode 22. Although not shown in Fig. 1, as will be described later, the multilayer coil component 1 also has a coil provided inside the element body 10A.

[0016] In this specification, the length direction, height direction, and width direction are defined as directions L, T, and W, respectively, as shown in Fig. 1 etc. Here, the length direction L, height direction T, and width direction W are perpendicular to each other.

[0017] The element body 10A has a first end face 11a and a second end face 11b facing each other in the longitudinal direction L, a first main face 12a and a second main face 12b facing each other in the height direction T, and a first side face 13a and a second side face 13b facing each other in the width direction W, and is, for example, rectangular or approximately rectangular.

[0018] The first end face 11a and the second end face 11b of the element body 10A do not need to be strictly perpendicular to the length direction L. Moreover, the first main surface 12a and the second main surface 12b of the element body 10A do not need to be strictly perpendicular to the height direction T. Furthermore, the first side surface 13a and the second side surface 13b of the element body 10A do not need to be strictly perpendicular to the width direction W.

[0019] When the multilayer coil component 1 is mounted on a substrate, the first main surface 12a of the element body 10A serves as the mounting surface.

[0020] The corners and ridges of element body 10A are preferably rounded. The corners of element body 10A are parts where three faces of element body 10A intersect. The ridges of element body 10A are parts where two faces of element body 10A intersect.

[0021] The first external electrode 21 is provided on the surface of the element body 10A. More specifically, the first external electrode 21 extends from the first end face 11a of the element body 10A over a portion of each of the first main surface 12a, the second main surface 12b, the first side surface 13a, and the second side surface 13b.

[0022] The arrangement of the first external electrode 21 is not limited to the arrangement shown in Fig. 1. For example, the first external electrode 21 may extend from a part of the first main surface 12a of the element body 10A to a part of each of the first end surface 11a, the first side surface 13a, and the second side surface 13b.

[0023] The second external electrode 22 is provided on the surface of the element body 10A. More specifically, the second external electrode 22 extends from the second end face 11b of the element body 10A over a portion of each of the first main surface 12a, the second main surface 12b, the first side surface 13a, and the second side surface 13b.

[0024] The arrangement of the second external electrode 22 is not limited to the arrangement shown in Fig. 1. For example, the second external electrode 22 may extend from a part of the first main surface 12a of the element body 10A to a part of each of the second end surface 11b, the first side surface 13a, and the second side surface 13b.

[0025] As described above, the first external electrode 21 and the second external electrode 22 are provided at positions spaced apart from each other on the surface of the element body 10A.

[0026] As described above, the first external electrode 21 and the second external electrode 22 are provided on the first main surface 12a of the element body 10A, which is the mounting surface, and this improves the mountability of the multilayer coil component 1.

[0027] The first external electrode 21 and the second external electrode 22 may each have a single-layer structure or a multi-layer structure.

[0028] When the first external electrode 21 and the second external electrode 22 each have a single-layer structure, examples of the constituent material of each external electrode include Ag, Au, Cu, Pd, Ni, Al, and alloys containing at least one of these metals.

[0029] When the first external electrode 21 and the second external electrode 22 each have a multi-layer structure, each external electrode may have, in order from the surface side of the base body 10A, for example, a base electrode containing Ag, a Ni-plated electrode, and a Sn-plated electrode.

[0030] Fig. 2 is a schematic perspective view showing an example of an exploded state of the multilayer coil component (excluding external electrodes) shown in Fig. 1. Fig. 3 is a schematic plan view showing an example of an exploded state of the multilayer coil component (excluding external electrodes) shown in Fig. 1.

[0031] As shown in FIGS. 2 and 3, the element body 10A is formed by stacking a plurality of insulating layers in a stacking direction, which is the length direction L in this example.

[0032] The base body 10A includes insulating layer P1, insulating layer P2, insulating layer P3, insulating layer P4, insulating layer P5, insulating layer P6, insulating layer P7, insulating layer P8, insulating layer P9, insulating layer P10, insulating layer P11, insulating layer P12, insulating layer P13, insulating layer P14, and insulating layer P15, in that order in the longitudinal direction L from the first end face 11a side toward the second end face 11b side.

[0033] The constituent material of each insulating layer may be, for example, a magnetic material such as a ferrite material.

[0034] The ferrite material is preferably a Ni-Cu-Zn based ferrite material.

[0035] When the total amount of the Ni-Cu-Zn ferrite material is taken as 100 mol%, it is preferable that the material contains Fe in an amount of 40 mol% to 49.5 mol% inclusive, calculated as Fe2O3, Zn in an amount of 2 mol% to 35 mol% inclusive, calculated as ZnO, Cu in an amount of 6 mol% to 13 mol% inclusive, and Ni in an amount of 10 mol% to 45 mol% inclusive, calculated as NiO.

[0036] The Ni-Cu-Zn ferrite material may further contain additives such as Co, Bi, Sn, and Mn.

[0037] The Ni—Cu—Zn ferrite material may further contain inevitable impurities.

[0038] A coil 30A is provided inside the element body 10A.

[0039] As shown in Figures 2 and 3, coil 30A includes coil conductor Q1, coil conductor Q2, coil conductor Q3, coil conductor Q4, coil conductor Q5, coil conductor Q6, coil conductor Q7, coil conductor Q8, coil conductor Q9, coil conductor Q10, coil conductor Q11, coil conductor Q12, coil conductor Q13, coil conductor Q14, and coil conductor Q15, arranged in that order in the longitudinal direction L.

[0040] The coil conductor Q1 is linear and is provided on the main surface of the insulating layer P1.

[0041] The coil conductor Q1 has a land portion Ra1 and a land portion Rb1 at separate ends.

[0042] The coil conductor Q2 is L-shaped and is provided on the main surface of the insulating layer P2.

[0043] Coil conductor Q2 has land portions Ra2 and Rc2 at separate ends.

[0044] The land portion Ra2 is connected to a via conductor Sa2 that penetrates the insulating layer P2 in the length direction L. The via conductor Sa2 is connected to the land portion Ra1 in addition to the land portion Ra2. That is, the land portion Ra1 and the land portion Ra2 are electrically connected via the via conductor Sa2.

[0045] The coil conductor Q2 has a bent portion Ub2.

[0046] The bent portion Ub2 is connected to a via conductor Sb2 that penetrates the insulating layer P2 in the longitudinal direction L. The via conductor Sb2 is connected to the land portion Rb1 in addition to the bent portion Ub2. That is, the land portion Rb1 and the bent portion Ub2 are electrically connected via the via conductor Sb2.

[0047] The coil conductor Q3 is U-shaped and is provided on the main surface of the insulating layer P3.

[0048] Coil conductor Q3 has land portions Ra3 and Rd3 at separate ends.

[0049] The land portion Ra3 is connected to a via conductor Sa3 that penetrates the insulating layer P3 in the length direction L. The via conductor Sa3 is connected to the land portion Ra2 in addition to the land portion Ra3. That is, the land portion Ra2 and the land portion Ra3 are electrically connected via the via conductor Sa3.

[0050] The coil conductor Q3 has a bent portion Ub3 and a bent portion Uc3.

[0051] The bend Ub3 is connected to a via conductor Sb3 that penetrates the insulating layer P3 in the length direction L. The via conductor Sb3 is connected to the bend Ub2 in addition to the bend Ub3. That is, the bend Ub2 and the bend Ub3 are electrically connected via the via conductor Sb3.

[0052] The bent portion Uc3 is connected to a via conductor Sc3 that penetrates the insulating layer P3 in the longitudinal direction L. The via conductor Sc3 is connected to the land portion Rc2 in addition to the bent portion Uc3. That is, the land portion Rc2 and the bent portion Uc3 are electrically connected via the via conductor Sc3.

[0053] The coil conductor Q4 is U-shaped and is provided on the main surface of the insulating layer P4.

[0054] Coil conductor Q4 has land portions Ra4 and Rb4 at separate ends.

[0055] The land portion Rb4 is connected to a via conductor Sb4 that penetrates the insulating layer P4 in the longitudinal direction L. The via conductor Sb4 is connected to the bend portion Ub3 in addition to the land portion Rb4. That is, the bend portion Ub3 and the land portion Rb4 are electrically connected via the via conductor Sb4.

[0056] The coil conductor Q4 has a bent portion Uc4 and a bent portion Ud4.

[0057] The bent portion Uc4 is connected to a via conductor Sc4 that penetrates the insulating layer P4 in the longitudinal direction L. The via conductor Sc4 is connected to the bent portion Uc3 in addition to the bent portion Uc4. That is, the bent portion Uc3 and the bent portion Uc4 are electrically connected via the via conductor Sc4.

[0058] The bent portion Ud4 is connected to a via conductor Sd4 that penetrates the insulating layer P4 in the longitudinal direction L. The via conductor Sd4 is connected to the land portion Rd3 in addition to the bent portion Ud4. That is, the land portion Rd3 and the bent portion Ud4 are electrically connected via the via conductor Sd4.

[0059] The coil conductor Q5 is U-shaped and is provided on the main surface of the insulating layer P5.

[0060] Coil conductor Q5 has land portions Rb5 and Rc5 at separate ends.

[0061] The land portion Rc5 is connected to a via conductor Sc5 that penetrates the insulating layer P5 in the longitudinal direction L. The via conductor Sc5 is connected to the bent portion Uc4 in addition to the land portion Rc5. That is, the bent portion Uc4 and the land portion Rc5 are electrically connected via the via conductor Sc5.

[0062] The coil conductor Q5 has a bent portion Ua5 and a bent portion Ud5.

[0063] The bent portion Ua5 is connected to a via conductor Sa5 that penetrates the insulating layer P5 in the longitudinal direction L. The via conductor Sa5 is connected to the land portion Ra4 in addition to the bent portion Ua5. That is, the land portion Ra4 and the bent portion Ua5 are electrically connected via the via conductor Sa5.

[0064] The bent portion Ud5 is connected to a via conductor Sd5 that penetrates the insulating layer P5 in the longitudinal direction L. The via conductor Sd5 is connected to the bent portion Ud4 in addition to the bent portion Ud5. That is, the bent portion Ud4 and the bent portion Ud5 are electrically connected via the via conductor Sd5.

[0065] The coil conductor Q6 is U-shaped and is provided on the main surface of the insulating layer P6.

[0066] Coil conductor Q6 has land portions Rc6 and Rd6 at separate ends.

[0067] The land portion Rd6 is connected to a via conductor Sd6 that penetrates the insulating layer P6 in the length direction L. The via conductor Sd6 is connected to the bent portion Ud5 in addition to the land portion Rd6. That is, the bent portion Ud5 and the land portion Rd6 are electrically connected via the via conductor Sd6.

[0068] The coil conductor Q6 has a bent portion Ua6 and a bent portion Ub6.

[0069] The bent portion Ua6 is connected to a via conductor Sa6 that passes through the insulating layer P6 in the longitudinal direction L. The via conductor Sa6 is connected to the bent portion Ua5 in addition to the bent portion Ua6. That is, the bent portion Ua5 and the bent portion Ua6 are electrically connected via the via conductor Sa6.

[0070] The bent portion Ub6 is connected to a via conductor Sb6 that passes through the insulating layer P6 in the longitudinal direction L. The via conductor Sb6 is connected to the land portion Rb5 in addition to the bent portion Ub6. That is, the land portion Rb5 and the bent portion Ub6 are electrically connected via the via conductor Sb6.

[0071] The coil conductor Q7 is U-shaped and is provided on the main surface of the insulating layer P7.

[0072] Coil conductor Q7 has land portions Ra7 and Rd7 at separate ends.

[0073] The land portion Ra7 is connected to a via conductor Sa7 that penetrates the insulating layer P7 in the length direction L. The via conductor Sa7 is connected to the bent portion Ua6 in addition to the land portion Ra7. That is, the bent portion Ua6 and the land portion Ra7 are electrically connected via the via conductor Sa7.

[0074] The coil conductor Q7 has a bent portion Ub7 and a bent portion Uc7.

[0075] The bend Ub7 is connected to a via conductor Sb7 that passes through the insulating layer P7 in the length direction L. The via conductor Sb7 is connected to the bend Ub6 in addition to the bend Ub7. That is, the bend Ub6 and the bend Ub7 are electrically connected via the via conductor Sb7.

[0076] The bent portion Uc7 is connected to a via conductor Sc7 that penetrates the insulating layer P7 in the longitudinal direction L. The via conductor Sc7 is connected to the land portion Rc6 in addition to the bent portion Uc7. That is, the land portion Rc6 and the bent portion Uc7 are electrically connected via the via conductor Sc7.

[0077] The coil conductor Q8 is U-shaped and is provided on the main surface of the insulating layer P8.

[0078] Coil conductor Q8 has land portions Ra8 and Rb8 at separate ends.

[0079] The land portion Rb8 is connected to a via conductor Sb8 that passes through the insulating layer P8 in the length direction L. The via conductor Sb8 is connected to the bend portion Ub7 in addition to the land portion Rb8. That is, the bend portion Ub7 and the land portion Rb8 are electrically connected via the via conductor Sb8.

[0080] The coil conductor Q8 has a bent portion Uc8 and a bent portion Ud8.

[0081] The bent portion Uc8 is connected to a via conductor Sc8 that passes through the insulating layer P8 in the longitudinal direction L. The via conductor Sc8 is connected to the bent portion Uc7 in addition to the bent portion Uc8. That is, the bent portion Uc7 and the bent portion Uc8 are electrically connected via the via conductor Sc8.

[0082] The bent portion Ud8 is connected to a via conductor Sd8 that penetrates the insulating layer P8 in the length direction L. The via conductor Sd8 is connected to the land portion Rd7 in addition to the bent portion Ud8. That is, the land portion Rd7 and the bent portion Ud8 are electrically connected via the via conductor Sd8.

[0083] The coil conductor Q9 is U-shaped and is provided on the main surface of the insulating layer P9.

[0084] Coil conductor Q9 has land portions Rb9 and Rc9 at separate ends.

[0085] The land portion Rc9 is connected to a via conductor Sc9 that penetrates the insulating layer P9 in the length direction L. The via conductor Sc9 is connected to the bent portion Uc8 in addition to the land portion Rc9. That is, the bent portion Uc8 and the land portion Rc9 are electrically connected via the via conductor Sc9.

[0086] The coil conductor Q9 has a bent portion Ua9 and a bent portion Ud9.

[0087] The bent portion Ua9 is connected to a via conductor Sa9 that passes through the insulating layer P9 in the longitudinal direction L. The via conductor Sa9 is connected to the land portion Ra8 in addition to the bent portion Ua9. That is, the land portion Ra8 and the bent portion Ua9 are electrically connected via the via conductor Sa9.

[0088] The bent portion Ud9 is connected to a via conductor Sd9 that passes through the insulating layer P9 in the length direction L. The via conductor Sd9 is connected to the bent portion Ud8 in addition to the bent portion Ud9. That is, the bent portion Ud8 and the bent portion Ud9 are electrically connected via the via conductor Sd9.

[0089] The coil conductor Q10 is U-shaped and is provided on the main surface of the insulating layer P10.

[0090] Coil conductor Q10 has land portions Rc10 and Rd10 at separate ends.

[0091] The land portion Rd10 is connected to a via conductor Sd10 that penetrates the insulating layer P10 in the length direction L. The via conductor Sd10 is connected to the bent portion Ud9 in addition to the land portion Rd10. That is, the bent portion Ud9 and the land portion Rd10 are electrically connected via the via conductor Sd10.

[0092] The coil conductor Q10 has a bent portion Ua10 and a bent portion Ub10.

[0093] The bent portion Ua10 is connected to a via conductor Sa10 that penetrates the insulating layer P10 in the length direction L. The via conductor Sa10 is connected to the bent portion Ua9 in addition to the bent portion Ua10. That is, the bent portion Ua9 and the bent portion Ua10 are electrically connected via the via conductor Sa10.

[0094] The bend Ub10 is connected to a via conductor Sb10 that passes through the insulating layer P10 in the length direction L. The via conductor Sb10 is connected to the land Rb9 in addition to the bend Ub10. That is, the land Rb9 and the bend Ub10 are electrically connected via the via conductor Sb10.

[0095] The coil conductor Q11 is U-shaped and is provided on the main surface of the insulating layer P11.

[0096] The coil conductor Q11 has a land portion Ra11 and a land portion Rd11 at separate ends.

[0097] The land portion Ra11 is connected to a via conductor Sa11 that penetrates the insulating layer P11 in the length direction L. The via conductor Sa11 is connected to the bent portion Ua10 in addition to the land portion Ra11. That is, the bent portion Ua10 and the land portion Ra11 are electrically connected via the via conductor Sa11.

[0098] The coil conductor Q11 has a bent portion Ub11 and a bent portion Uc11.

[0099] The bend Ub11 is connected to a via conductor Sb11 that passes through the insulating layer P11 in the length direction L. The via conductor Sb11 is connected to the bend Ub10 in addition to the bend Ub11. That is, the bend Ub10 and the bend Ub11 are electrically connected via the via conductor Sb11.

[0100] The bent portion Uc11 is connected to a via conductor Sc11 that penetrates the insulating layer P11 in the longitudinal direction L. The via conductor Sc11 is connected to the land portion Rc10 in addition to the bent portion Uc11. That is, the land portion Rc10 and the bent portion Uc11 are electrically connected through the via conductor Sc11.

[0101] The coil conductor Q12 is U-shaped and is provided on the main surface of the insulating layer P12.

[0102] Coil conductor Q12 has land portions Ra12 and Rb12 at separate ends.

[0103] The land portion Rb12 is connected to a via conductor Sb12 that penetrates the insulating layer P12 in the length direction L. The via conductor Sb12 is connected to the bend portion Ub11 in addition to the land portion Rb12. That is, the bend portion Ub11 and the land portion Rb12 are electrically connected via the via conductor Sb12.

[0104] The coil conductor Q12 has a bent portion Uc12 and a bent portion Ud12.

[0105] The bent portion Uc12 is connected to a via conductor Sc12 that penetrates the insulating layer P12 in the longitudinal direction L. The via conductor Sc12 is connected to the bent portion Uc11 in addition to the bent portion Uc12. That is, the bent portion Uc11 and the bent portion Uc12 are electrically connected via the via conductor Sc12.

[0106] The bent portion Ud12 is connected to a via conductor Sd12 that penetrates the insulating layer P12 in the longitudinal direction L. The via conductor Sd12 is connected to the land portion Rd11 in addition to the bent portion Ud12. That is, the land portion Rd11 and the bent portion Ud12 are electrically connected via the via conductor Sd12.

[0107] The coil conductor Q13 is U-shaped and is provided on the main surface of the insulating layer P13.

[0108] Coil conductor Q13 has land portions Rb13 and Rc13 at separate ends.

[0109] The land portion Rc13 is connected to a via conductor Sc13 that penetrates the insulating layer P13 in the length direction L. The via conductor Sc13 is connected to the bent portion Uc12 in addition to the land portion Rc13. That is, the bent portion Uc12 and the land portion Rc13 are electrically connected via the via conductor Sc13.

[0110] The coil conductor Q13 has a bent portion Ua13 and a bent portion Ud13.

[0111] The bent portion Ua13 is connected to a via conductor Sa13 that penetrates the insulating layer P13 in the length direction L. The via conductor Sa13 is connected to the land portion Ra12 in addition to the bent portion Ua13. That is, the land portion Ra12 and the bent portion Ua13 are electrically connected via the via conductor Sa13.

[0112] The bent portion Ud13 is connected to a via conductor Sd13 that penetrates the insulating layer P13 in the length direction L. The via conductor Sd13 is connected to the bent portion Ud12 in addition to the bent portion Ud13. That is, the bent portion Ud12 and the bent portion Ud13 are electrically connected via the via conductor Sd13.

[0113] The coil conductor Q14 is L-shaped and is provided on the main surface of the insulating layer P14.

[0114] The coil conductor Q14 has a land portion Rb14 and a land portion Rd14 at separate ends.

[0115] The land portion Rb14 is connected to a via conductor Sb14 that penetrates the insulating layer P14 in the length direction L. The via conductor Sb14 is connected to the land portion Rb13 in addition to the land portion Rb14. That is, the land portion Rb13 and the land portion Rb14 are electrically connected via the via conductor Sb14.

[0116] The land portion Rd14 is connected to a via conductor Sd14 that penetrates the insulating layer P14 in the length direction L. The via conductor Sd14 is connected to the bent portion Ud13 in addition to the land portion Rd14. That is, the bent portion Ud13 and the land portion Rd14 are electrically connected via the via conductor Sd14.

[0117] The coil conductor Q14 has a bent portion Ua14.

[0118] The bent portion Ua14 is connected to a via conductor Sa14 that penetrates the insulating layer P14 in the length direction L. The via conductor Sa14 is connected to the bent portion Ua13 in addition to the bent portion Ua14. That is, the bent portion Ua13 and the bent portion Ua14 are electrically connected via the via conductor Sa14.

[0119] The coil conductor Q15 is linear and is provided on the main surface of the insulating layer P15.

[0120] Coil conductor Q15 has land portions Ra15 and Rb15 at separate ends.

[0121] The land portion Ra15 is connected to a via conductor Sa15 that penetrates the insulating layer P15 in the length direction L. The via conductor Sa15 is connected to the bent portion Ua14 in addition to the land portion Ra15. That is, the bent portion Ua14 and the land portion Ra15 are electrically connected via the via conductor Sa15.

[0122] The land portion Rb15 is connected to a via conductor Sb15 that penetrates the insulating layer P15 in the length direction L. The via conductor Sb15 is connected to the land portion Rb14 in addition to the land portion Rb15. That is, the land portion Rb14 and the land portion Rb15 are electrically connected via the via conductor Sb15.

[0123] In this specification, the L-shape may be any shape in which two sides are substantially perpendicular to each other, and does not necessarily have to be a shape in which the two sides are strictly perpendicular to each other.

[0124] In this specification, the U-shape may be any shape in which two adjacent sides of the three sides are approximately perpendicular to each other, and does not necessarily have to be a shape in which two adjacent sides of the three sides are strictly perpendicular to each other.

[0125] In the multilayer coil component 1, as described above, the insulating layer P1, the insulating layer P2, the insulating layer P3, the insulating layer P4, the insulating layer P5, the insulating layer P6, the insulating layer P7, the insulating layer P8, the insulating layer P9, the insulating layer P10, the insulating layer P11, the insulating layer P12, the insulating layer P13, the insulating layer P14, and the insulating layer P15 are stacked in this order in the longitudinal direction L. As a result, the coil conductor Q1, the coil conductor Q2, the coil conductor Q3, the coil conductor Q4, the coil conductor Q5, the coil conductor Q6, the coil conductor Q7, the coil conductor Q8, the coil conductor Q9, the coil conductor Q10, the coil conductor Q11, the coil conductor Q12, the coil conductor Q13, the coil conductor Q14, and the coil conductor Q15 are stacked in this order in the longitudinal direction L together with the insulating layers and are electrically connected to each other through the via conductors, thereby forming the coil 30A.

[0126] The coil 30A is, for example, in the form of a solenoid.

[0127] When viewed from the longitudinal direction L, the coil 30A may have a shape composed of straight portions (e.g., a polygonal shape) as shown in Figures 2 and 3, a shape composed of curved portions (e.g., a circular shape), or a shape composed of straight portions and curved portions.

[0128] In the multilayer coil component of the present invention, it is preferable that the stacking direction and the direction of the coil axis of the coil are parallel to the mounting surface of the element body along the same direction.

[0129] In element body 10A, the stacking direction of the insulating layers is parallel to length direction L. In other words, the stacking direction of the insulating layers is parallel to first main surface 12a of element body 10A, which is the mounting surface.

[0130] The coil 30A has a coil axis C. The coil axis C of the coil 30A corresponds to the central axis of the coil 30A when viewed in the longitudinal direction L, and extends in the longitudinal direction L. In other words, the direction of the coil axis C of the coil 30A is parallel to the first main surface 12a of the element body 10A, which is the mounting surface.

[0131] Therefore, in the laminated coil component 1, the lamination direction of the insulating layers and the direction of the coil axis C of the coil 30A are along the same length direction L and are parallel to the first main surface 12a of the element body 10A, which is the mounting surface.

[0132] In the multilayer coil component 1, the stacking direction of the insulating layers and the direction of the coil axis C of the coil 30A are shown to be along the same length direction L and parallel to the first main surface 12a of the element body 10A, which is the mounting surface. However, the stacking direction of the insulating layers and the direction of the coil axis of the coil may be perpendicular to the first main surface of the element body, which is the mounting surface.

[0133] In the multilayer coil component 1, the multiple coil conductors stacked in the length direction L include a first multilayer portion Ea1.

[0134] The first lamination unit Ea1 is made up of three adjacent coil conductors: a coil conductor Q3, a coil conductor Q4, and a coil conductor Q5.

[0135] The first laminated portion Ea1 has a first parallel running section Ma1 in which all of the coil conductors that make up the first laminated portion Ea1, i.e., the coil conductor Q3, the coil conductor Q4, and the coil conductor Q5, overlap when viewed from the longitudinal direction L.

[0136] In the first parallel running section Ma1, the via conductors Sc4, Sd4, Sc5, and Sd5 are connected in parallel, that is, the coil conductors Q3, Q4, and Q5 are connected in parallel in the first parallel running section Ma1.

[0137] The coil conductor Q3, the coil conductor Q4, and the coil conductor Q5 do not overlap with each other when viewed from the longitudinal direction L, except in the first parallel running section Ma1.

[0138] In the multilayer coil component 1, the multiple coil conductors stacked in the length direction L further include a second multilayer portion Fa1 in addition to the first multilayer portion Ea1.

[0139] The second laminated portion Fa1 is made up of three adjacent coil conductors Q7, Q8, and Q9, which is the same number as the first laminated portion Ea1.

[0140] The second laminated portion Fa1 has a second parallel running section Na1 in which all of the coil conductors that make up the second laminated portion Fa1, i.e., coil conductor Q7, coil conductor Q8, and coil conductor Q9, overlap when viewed from the longitudinal direction L.

[0141] The second parallel running section Na1 is connected in parallel by via conductor Sc8, via conductor Sd8, via conductor Sc9, and via conductor Sd9. That is, the coil conductor Q7, coil conductor Q8, and coil conductor Q9 are connected in parallel in the second parallel running section Na1.

[0142] The coil conductor Q7, the coil conductor Q8, and the coil conductor Q9 do not overlap with each other when viewed from the longitudinal direction L, except in the second parallel running section Na1.

[0143] The first parallel running section Ma1 and the second parallel running section Na1 overlap each other when viewed in the longitudinal direction L.

[0144] Although the first multilayer section Ea1 and the second multilayer section Fa1 have been exemplified above as multilayer sections each consisting of three adjacent coil conductors in the multilayer coil component 1, the same applies to multilayer sections each consisting of other combinations of three adjacent coil conductors. In other words, in the multilayer coil component 1, the three adjacent coil conductors are connected in parallel in the parallel-running sections where these coil conductors overlap when viewed from the longitudinal direction L.

[0145] In the multilayer coil component 1, three adjacent coil conductors are connected in parallel in the parallel-running sections, which increases the cross-sectional area of ​​the coil 30A in the direction along the current path of the coil 30A, i.e., perpendicular to the direction in which the coil conductors extend. Therefore, in the multilayer coil component 1, the direct current resistance (Rdc) of the coil 30A is low, allowing a large current to flow through the coil 30A.

[0146] In the multilayer coil component of the present invention, the length of all of the coil conductors constituting the multilayer portion may be a length of ¾ turns of the coil.

[0147] In the multilayer coil component 1, for example, the length of all the coil conductors constituting the first multilayer unit Ea1 is the length of ¾ of the turn of the coil 30A. Also, in the multilayer coil component 1, for example, the length of all the coil conductors constituting the second multilayer unit Fa1 is the length of ¾ of the turn of the coil 30A.

[0148] In this specification, the length of the coil conductor means the length in the direction in which the coil conductor extends on a plane perpendicular to the stacking direction (length direction L in Figures 2 and 3) when viewed from the stacking direction.

[0149] The element body 10A further includes an insulating layer Px.

[0150] The insulating layer Px is laminated on the first end face 11a side of the insulating layer P1, that is, on the side of the insulating layer P1 opposite to the insulating layer P2.

[0151] An extension land portion Rax is provided on the main surface of the insulating layer Px. The extension land portion Rax is connected to an extension via conductor Saax that penetrates the insulating layer Px in the length direction L. The extension land portion Rax is connected to the extension via conductor Saax as well as to an extension via conductor Saa1 that penetrates the insulating layer P1 in the length direction L. This forms a first extension conductor 41 consisting of the extension land portion Rax, the extension via conductor Saax, and the extension via conductor Saa1.

[0152] The extraction via conductor Saa1 is connected to the land portion Ra1 in addition to the extraction land portion Rax. That is, the first extraction conductor 41 is connected to the coil 30A.

[0153] FIG. 4 is an enlarged schematic cross-sectional view showing an example of the vicinity of the first end face of the element body in the multilayer coil component shown in FIG. 1, as viewed in the height direction.

[0154] 4, the insulating layer Px is stacked on the side of the insulating layer P1 opposite the insulating layer P2, so that the first extension conductor 41 is exposed from the first end surface 11a of the element body 10A. The exposed portion of the first extension conductor 41 is connected to the first external electrode 21 provided on the first end surface 11a of the element body 10A.

[0155] Therefore, the coil 30A and the first external electrode 21 are electrically connected via the first extension conductor 41.

[0156] In FIG. 4, for the sake of convenience, the boundaries between the insulating layers are shown, but in reality these boundaries are not clearly visible.

[0157] The extension land portion Rax is connected to an extension via conductor Sabx that is spaced apart from the extension via conductor Saax and penetrates the insulating layer Px in the length direction L. The extension land portion Rax is connected to the extension via conductor Sabx as well as to the extension via conductor Sab1 that penetrates the insulating layer P1 in the length direction L. This forms a second extension conductor 42 that is made up of the extension land portion Rax, the extension via conductor Sabx, and the extension via conductor Sab1. Meanwhile, the extension via conductor Sab1 is connected to the land portion Rax as well as the land portion Ra1. In other words, the second extension conductor 42 is connected to the coil 30A.

[0158] Since the insulating layer Px is stacked on the side of the insulating layer P1 opposite the insulating layer P2, the second extension conductor 42 is exposed from the first end surface 11a of the element body 10A. The exposed portion of the second extension conductor 42 is connected to the first external electrode 21 provided on the first end surface 11a of the element body 10A. A cross-sectional view showing the connection between the second extension conductor 42 and the first external electrode 21 is similar to FIG. 4, which is a cross-sectional view showing the connection between the first extension conductor 41 and the first external electrode 21.

[0159] Therefore, the coil 30A and the first external electrode 21 are electrically connected via the second lead conductor .

[0160] As described above, the coil 30A is electrically connected to the same first external electrode 21 via the first extension conductor 41 and the second extension conductor 42. This allows the current path between the coil 30A and the first external electrode 21 to be divided into two paths, the first extension conductor 41 and the second extension conductor 42, thereby reducing the current density per extension conductor. Therefore, in the multilayer coil component 1, even if a large current flows between the coil 30A and the first external electrode 21, heat generation and electromigration can be suppressed in one extension conductor compared to when the coil 30A and the first external electrode 21 are electrically connected by only one extension conductor. If the coil 30A and the first external electrode 21 are electrically connected by only one extension conductor, heat generation and electromigration causing disconnection in the extension conductor may cause the multilayer coil component to malfunction. In contrast, in the multilayer coil component 1, heat generation and electromigration can be suppressed in one lead conductor, thereby suppressing disconnection of the lead conductor, even when a large current flows between the coil 30A and the first external electrode 21. Furthermore, in the unlikely event that a disconnection occurs in one of the first lead conductor 41 and the second lead conductor 42, the function of the multilayer coil component can be maintained by the other.

[0161] The number of insulating layers Px may be one or more.

[0162] When the number of insulating layers Px is plural, the first extension conductor 41 is formed by alternately connecting a plurality of extension land portions Rax and a plurality of extension via conductors Saax, and further connecting an extension via conductor Saa1.

[0163] When there are a plurality of insulating layers Px, the second extension conductor 42 is formed by alternately connecting a plurality of extension land portions Rax and a plurality of extension via conductors Sabx, and further connecting an extension via conductor Sab1.

[0164] The element body 10A further includes an insulating layer Py.

[0165] The insulating layer Py is laminated on the second end face 11b side of the insulating layer P15, that is, on the side of the insulating layer P15 opposite to the insulating layer P14.

[0166] An extension land Rby is provided on the main surface of the insulating layer Py. The extension land Rby is connected to an extension via conductor Sbay that penetrates the insulating layer Py in the length direction L. This forms a third extension conductor 43 consisting of the extension land Rby and the extension via conductor Sbay.

[0167] The extraction via conductor Sbay is connected to the extraction land portion Rby as well as the land portion Rb15. That is, the third extraction conductor 43 is connected to the coil 30A.

[0168] FIG. 5 is an enlarged schematic cross-sectional view showing an example of the vicinity of the second end face of the element body in the multilayer coil component shown in FIG. 1, as viewed in the height direction.

[0169] 5, the insulating layer Py is stacked on the side of the insulating layer P15 opposite the insulating layer P14, so that the third extension conductor 43 is exposed from the second end surface 11b of the element body 10A. The exposed portion of the third extension conductor 43 is connected to the second external electrode 22 provided on the second end surface 11b of the element body 10A.

[0170] Therefore, the coil 30A and the second external electrode 22 are electrically connected via the third lead conductor 43.

[0171] In FIG. 5, for the sake of convenience, the boundaries between the insulating layers are shown, but in reality, these boundaries are not clearly visible.

[0172] The extension land portion Rby is connected to an extension via conductor Sbby that is spaced apart from the extension via conductor Sbay and penetrates the insulating layer Py in the length direction L. This forms a fourth extension conductor 44 consisting of the extension land portion Rby and the extension via conductor Sbby. Meanwhile, the extension via conductor Sbby is connected to the land portion Rb15 in addition to the extension land portion Rby. That is, the fourth extension conductor 44 is connected to the coil 30A.

[0173] Since the insulating layer Py is stacked on the side of the insulating layer P15 opposite the insulating layer P14, the fourth extension conductor 44 is exposed from the second end surface 11b of the element body 10A. The exposed portion of the fourth extension conductor 44 is connected to the second external electrode 22 provided on the second end surface 11b of the element body 10A. A cross-sectional view showing the connection between the fourth extension conductor 44 and the second external electrode 22 is similar to FIG. 5, which is a cross-sectional view showing the connection between the third extension conductor 43 and the second external electrode 22.

[0174] Therefore, the coil 30A and the second external electrode 22 are electrically connected via the fourth extension conductor 44.

[0175] As a result, the coil 30A is electrically connected to the same second external electrode 22 via the third lead conductor 43 and the fourth lead conductor 44. This allows the current path between the coil 30A and the second external electrode 22 to be divided into two paths, the third lead conductor 43 and the fourth lead conductor 44, thereby reducing the current density per lead conductor. Therefore, in the multilayer coil component 1, even if a large current flows between the coil 30A and the second external electrode 22, heat generation and electromigration can be suppressed in one lead conductor compared to when the coil 30A and the second external electrode 22 are electrically connected by only one lead conductor. If the coil 30A and the second external electrode 22 are electrically connected by only one lead conductor, heat generation and electromigration causing disconnection in the lead conductor may cause the multilayer coil component to malfunction. In contrast, in the multilayer coil component 1, heat generation and electromigration can be suppressed in one of the lead conductors, thereby suppressing disconnection of the lead conductor, even when a large current flows between the coil 30A and the second external electrode 22. Furthermore, in the unlikely event that a disconnection occurs in one of the third lead conductor 43 and the fourth lead conductor 44, the function of the multilayer coil component can be maintained by the other.

[0176] The number of insulating layers Py may be one or more.

[0177] When the number of insulating layers Py is plural, the third extension conductor 43 is formed by alternately connecting a plurality of extension lands Rby and a plurality of extension via conductors Sbay.

[0178] When the number of insulating layers Py is plural, the fourth extension conductor 44 is formed by alternately connecting a plurality of extension lands Rby and a plurality of extension via conductors Sbby.

[0179] The number of insulating layers Px and the number of insulating layers Py may be the same as or different from each other.

[0180] Examples of materials constituting each coil conductor (including the land portion), each via conductor, and each lead-out via conductor include Ag, Au, Cu, Pd, Ni, Al, and alloys containing at least one of these metals.

[0181] When viewed from the longitudinal direction L, each coil conductor may have a shape composed of straight portions as shown in Figures 2 and 3, a shape composed of curved portions, or a shape composed of straight and curved portions.

[0182] When viewed in the length direction L, each land portion may be circular or polygonal.

[0183] When viewed in the length direction L, each via conductor may have a circular shape or a polygonal shape.

[0184] When viewed from the length direction L, each of the extraction via conductors may have a circular shape or a polygonal shape.

[0185] Each of the coil conductors and each of the lead conductors may not independently have a land portion.

[0186] In the multilayer coil component 1, the diameter of the lead via conductor is 100 μm or less. This reduces the degree of thermal contraction of the lead via conductor during the process of manufacturing the lead conductor. Therefore, the exposed portion of the lead conductor exposed on the surface of the element body 10A is less likely to be recessed into the surrounding insulating layer. As a result, the multilayer coil component 1 is less likely to have poor appearance due to recesses in the exposed portion of the lead conductor.

[0187] On the other hand, in the multilayer coil component 1, the diameter of the lead via conductor is 100 μm or less, which reduces the cross-sectional area of ​​the lead via conductor, and as a result, there is a risk of the DC resistance of the lead conductor increasing. In contrast, in the multilayer coil component 1, as described above, the coil 30A is electrically connected to the same external electrode via two lead conductors, and therefore the current density per lead conductor can be reduced. In the multilayer coil component 1, by reducing the current density per lead conductor, the influence of increased DC resistance of the lead conductor can be suppressed.

[0188] In the laminated coil component 1, for at least one lead conductor selected from the group consisting of the first lead conductor 41, the second lead conductor 42, the third lead conductor 43, and the fourth lead conductor 44, the diameter of the lead via conductor constituting that lead conductor may be 100 μm or less.

[0189] In the multilayer coil component 1, it is particularly preferable that the diameters of the extraction via conductors constituting the first extension conductor 41, the second extension conductor 42, the third extension conductor 43, and the fourth extension conductor 44 are all 100 μm or less.

[0190] In the multilayer coil component 1, the diameter of the lead-out via conductor is preferably 70 μm or more, from the viewpoint of preventing the direct current resistance of the lead-out conductor from becoming too high.

[0191] In the laminated coil component 1, for at least one lead conductor selected from the group consisting of the first lead conductor 41, the second lead conductor 42, the third lead conductor 43, and the fourth lead conductor 44, it is preferable that the diameter of the lead via conductor constituting that lead conductor is 70 μm or more.

[0192] In the multilayer coil component 1, it is particularly preferable that the diameters of the extraction via conductors constituting the first extension conductor 41, the second extension conductor 42, the third extension conductor 43, and the fourth extension conductor 44 are all 70 μm or more.

[0193] In the multilayer coil component 1, the diameter of the extraction via conductor that constitutes the first extraction conductor 41 is determined as follows.

[0194] First, while polishing the multilayer coil component 1 from the first side surface 13a toward the second side surface 13b of the element body 10A, cross sections perpendicular to the width direction W, i.e., cross sections along the length direction L and the height direction T, are sequentially observed along the width direction W, and cross-sectional images of the extraction via conductors (including the extraction via conductors Saax and Saa1) that constitute the first extraction conductor 41 are taken with a digital microscope. Next, image analysis software is used to perform image analysis on each of the taken cross-sectional images, thereby measuring the dimensions of the extraction via conductors in the height direction T. Then, the maximum value of the dimensions of the extraction via conductors in the height direction T measured for each cross-sectional image is determined to be the diameter of the extraction via conductor that constitutes the first extraction conductor 41.

[0195] The diameters of the extraction via conductors constituting the second extraction conductor 42, the third extraction conductor 43, and the fourth extraction conductor 44 are determined in the same manner as the diameter of the extraction via conductor constituting the first extraction conductor 41.

[0196] In the multilayer coil component of the present invention, when a first cross section perpendicular to the extension direction of the extraction conductor and a second cross section perpendicular to the extension direction of the coil conductor are defined, it is preferable that the total cross-sectional area of ​​the extraction via conductors constituting the multiple extraction conductors connected to the same external electrode, as defined in the same first cross section, is equal to or greater than the total cross-sectional area of ​​the coil conductors constituting the parallel running section, as defined in the same second cross section.

[0197] In the multilayer coil component 1, a first cross section perpendicular to the direction in which the lead conductors extend and a second cross section perpendicular to the direction in which the coil conductors extend are defined. Hereinafter, a cross section perpendicular to the length direction L in which the lead conductors extend, i.e., a cross section along the height direction T and the width direction W, will be defined as the first cross section, in accordance with FIGS. 2 and 3 . Also, a cross section perpendicular to the height direction T in which the coil conductors extend, i.e., a cross section along the length direction L and the width direction W, will be defined as the second cross section, in accordance with FIGS. 2 and 3 . Note that, since the coil conductors extend in the width direction W in addition to the height direction T, as shown in FIGS. 2 and 3 , a cross section perpendicular to the width direction W, i.e., a cross section along the length direction L and the height direction T, may be defined as the second cross section.

[0198] In the multilayer coil component 1, the sum of the cross-sectional areas of the extension via conductors constituting two extension conductors connected to the same external electrode, as determined in the same first cross section, is equal to or greater than the sum of the cross-sectional areas of the coil conductors constituting the parallel-running section, as determined in the same second cross section. More specifically, in the multilayer coil component 1, the sum of the cross-sectional areas of the extension via conductors constituting the first extension conductor 41 and the extension via conductors constituting the second extension conductor 42, as determined in the same first cross section, is equal to or greater than the sum of the cross-sectional areas of the three coil conductors constituting the parallel-running section, as determined in the same second cross section. Furthermore, in the multilayer coil component 1, the sum of the cross-sectional areas of the extension via conductors constituting the third extension conductor 43 and the extension via conductors constituting the fourth extension conductor 44, as determined in the same first cross section, is equal to or greater than the sum of the cross-sectional areas of the three coil conductors constituting the parallel-running section, as determined in the same second cross section. This allows the current density per extension conductor to be sufficiently low. Therefore, in the multilayer coil component 1, even if a large current flows between the coil 30A and the external electrodes, heat generation and electromigration in one lead conductor can be suppressed.

[0199] In the laminated coil component 1, for at least one of the combination of the first extraction conductor 41 and the second extraction conductor 42 and the combination of the third extraction conductor 43 and the fourth extraction conductor 44, it is preferable that the total cross-sectional area of ​​the extraction via conductors defined in the same first cross section is equal to or greater than the total cross-sectional area of ​​the three coil conductors constituting the parallel section defined in the same second cross section.

[0200] As described above, in the laminated coil component 1, for both the combination of the first extraction conductor 41 and the second extraction conductor 42 and the combination of the third extraction conductor 43 and the fourth extraction conductor 44, it is particularly preferable that the total cross-sectional area of ​​the extraction via conductors defined in the same first cross section is equal to or greater than the total cross-sectional area of ​​the three coil conductors constituting the parallel section defined in the same second cross section.

[0201] In the multilayer coil component 1, the sum of the cross-sectional area of ​​the extraction via conductor that constitutes the first extraction conductor 41 and the cross-sectional area of ​​the extraction via conductor that constitutes the second extraction conductor 42, which are determined in the same first cross section, is determined as follows.

[0202] First, while polishing the multilayer coil component 1 from the first side surface 13a side toward the second side surface 13b side of the element body 10A, cross sections perpendicular to the width direction W, i.e., cross sections along the length direction L and the height direction T, are sequentially observed along the width direction W, and cross-sectional images of the extraction via conductors (including the extraction via conductors Saax and Saa1) that constitute the first extraction conductor 41 and the extraction via conductors (including the extraction via conductors Sabx and Sab1) that constitute the second extraction conductor 42 are taken with a digital microscope. Next, image analysis software is used to measure the dimensions of the extraction via conductors that constitute the first extraction conductor 41 in the height direction T. The maximum value of the dimensions of the extraction via conductors measured for each cross-sectional image in the height direction T is determined as the diameter of the extraction via conductor that constitutes the first extraction conductor 41, and the circle-equivalent area calculated from this diameter is determined as the cross-sectional area of ​​the extraction via conductor that constitutes the first extraction conductor 41. Similarly, the cross-sectional area of ​​the extraction via conductor constituting the second extraction conductor 42 is determined. Then, the sum of the cross-sectional areas of the extraction via conductor constituting the first extraction conductor 41 and the extraction via conductor constituting the second extraction conductor 42, each determined by the above-mentioned method, is determined to be the sum of the cross-sectional areas of the extraction via conductor constituting the first extraction conductor 41 and the extraction via conductor constituting the second extraction conductor 42, which are determined on the same first cross section.

[0203] In the laminated coil component 1, the sum of the cross-sectional areas of the extraction via conductors constituting the third extraction conductor 43 and the extraction via conductors constituting the fourth extraction conductor 44, which are determined on the same first cross section, is determined in the same manner as the sum of the cross-sectional areas of the extraction via conductors constituting the first extraction conductor 41 and the second extraction conductor 42.

[0204] In the multilayer coil component 1, the total cross-sectional area of ​​the three coil conductors that form the parallel running section, which is determined by the same second cross section, is determined as follows.

[0205] FIG. 6 is an enlarged cross-sectional schematic view showing an example of three coil conductors constituting the parallel running section in the multilayer coil component shown in FIGS. 2 and 3, as viewed in the height direction.

[0206] First, while polishing the multilayer coil component 1 from the second main surface 12b side toward the first main surface 12a side of the element body 10A, a second cross section along the length direction L and width direction W is sequentially observed along the height direction T, and cross-sectional images of the coil conductors Q3, Q4, and Q5 constituting the first parallel running section Ma1, as shown in FIG. 6, are captured with a digital microscope. At this time, cross-sectional images of the coil conductors Q3, Q4, and Q5 constituting the first parallel running section Ma1, excluding the land portions, are captured. Next, image analysis software is used to measure the sum of the cross-sectional areas of the coil conductors Q3, Q4, and Q5 for each cross-sectional image. The maximum value of the sum of the cross-sectional areas of the coil conductors measured for each cross-sectional image is defined as the sum of the cross-sectional areas of the coil conductors constituting the first parallel running section Ma1, as determined in the same second cross section.

[0207] In the laminated coil component 1, there are parallel sections other than the first parallel section Ma1 (for example, the second parallel section Na1) in which three adjacent coil conductors overlap when viewed from the longitudinal direction L, but the sum of the cross-sectional areas of the three coil conductors constituting the parallel sections other than the first parallel section Ma1 is determined in the same manner as the sum of the cross-sectional areas of the coil conductors constituting the first parallel section Ma1.

[0208] In the laminated coil component 1, it is preferable that, for at least one of all parallel sections, the sum of the cross-sectional areas of the extraction via conductors constituting two extraction conductors connected to the same external electrode and defined by the same first cross-section is equal to or greater than the sum of the cross-sectional areas of the three coil conductors constituting the parallel section and defined by the same second cross-section.

[0209] In the multilayer coil component of the present invention, the multiple coil conductors stacked in the stacking direction may include an outermost coil conductor located at the outermost position in the stacking direction, and the outermost coil conductor may have a land portion at an end thereof, and it is preferable that the multiple lead-out conductors are connected to the same land portion.

[0210] In the multilayer coil component 1, the multiple coil conductors stacked in the longitudinal direction L include a coil conductor Q1 as the outermost coil conductor located at the outermost position in the longitudinal direction L. The coil conductor Q1 has a land portion Ra1 at its end. The first lead conductor 41 and the second lead conductor 42 are connected to the same land portion Ra1.

[0211] In the multilayer coil component 1, the embodiment in which both the first and second lead conductors 41 and 42 are connected to the land portion Ra1 of the coil conductor Q1, which is the outermost coil conductor, has been illustrated. However, the connection positions of the first and second lead conductors 41 and 42 to the coil 30A are not limited to the embodiment. For example, one of the first and second lead conductors 41 and 42 may be connected to the land portion Ra1 of the coil conductor Q1, and the other may be connected to the land portion Rb1 of the coil conductor Q1. Furthermore, one of the first and second lead conductors 41 and 42 may be connected to the land portion Ra1 or the land portion Rb1 of the coil conductor Q1, and the other may be connected to a portion of the coil conductor Q1 other than the land portion Ra1 or the land portion Rb1. Furthermore, both the first and second lead conductors 41 and 42 may be connected to a portion of the coil conductor Q1 other than the land portion Ra1 or the land portion Rb1.

[0212] In the multilayer coil component 1, the multiple coil conductors stacked in the longitudinal direction L include, in addition to the coil conductor Q1, a coil conductor Q15 as the outermost coil conductor located at the outermost position in the longitudinal direction L. The coil conductor Q15 has a land portion Rb15 at its end. The third lead conductor 43 and the fourth lead conductor 44 are connected to the same land portion Rb15.

[0213] In the multilayer coil component 1, the third and fourth lead conductors 43 and 44 are both connected to the land portion Rb15 of the coil conductor Q15, which is the outermost coil conductor, as illustrated. However, the connection positions of the third and fourth lead conductors 43 and 44 to the coil 30A are not limited to the above. For example, one of the third and fourth lead conductors 43 and 44 may be connected to the land portion Rb15 of the coil conductor Q15, and the other may be connected to the land portion Ra15 of the coil conductor Q15. Alternatively, one of the third and fourth lead conductors 43 and 44 may be connected to the land portion Ra15 or the land portion Rb15 of the coil conductor Q15, and the other may be connected to a portion of the coil conductor Q15 other than the land portion Ra15 or the land portion Rb15. Furthermore, both the third and fourth lead conductors 43 and 44 may be connected to a portion of the coil conductor Q15 other than the land portion Ra15 or the land portion Rb15.

[0214] The laminated coil component 1 may have only the first lead conductor 41 and the second lead conductor 42 as lead conductors, or may have only the third lead conductor 43 and the fourth lead conductor 44, or may have all of the first lead conductor 41, the second lead conductor 42, the third lead conductor 43, and the fourth lead conductor 44.

[0215] While the above describes an example in which the number of coil conductors connected in parallel in the parallel running section is three, the same applies to an example in which the number of coil conductors connected in parallel in the parallel running section is two, and further to an example in which the number of coil conductors connected in parallel in the parallel running section is four or more. In particular, from the viewpoint of reducing the DC resistance of the coil, it is preferable that the number of coil conductors connected in parallel in the parallel running section is three or more. In other words, in the multilayer coil component of the present invention, the multilayer section preferably includes three or more of the above coil conductors.

[0216] Although the above describes an example in which the number of lead conductors connected to the same external electrode is two, the same applies to an example in which the number of lead conductors connected to the same external electrode is three or more.

[0217] The multilayer coil component 1 is manufactured, for example, by the following method.

[0218] <Magnetic material manufacturing process> First, Fe2O3, ZnO, CuO, and NiO are weighed out to have a predetermined ratio.

[0219] Next, these weighed materials and pure water are placed in a ball mill together with PSZ media, mixed, and then pulverized. The mixing and pulverization time is, for example, 4 hours or more and 8 hours or less.

[0220] The resulting pulverized product is then dried and then calcined at a temperature of, for example, 700° C. to 800° C. for, for example, 2 hours to 5 hours.

[0221] In this manner, a powdered magnetic material, more specifically, a powdered magnetic ferrite material is produced.

[0222] The ferrite material is preferably a Ni-Cu-Zn based ferrite material.

[0223] When the total amount of the Ni-Cu-Zn ferrite material is taken as 100 mol%, it is preferable that the material contains Fe in an amount of 40 mol% to 49.5 mol% inclusive, calculated as Fe2O3, Zn in an amount of 2 mol% to 35 mol% inclusive, calculated as ZnO, Cu in an amount of 6 mol% to 13 mol% inclusive, and Ni in an amount of 10 mol% to 45 mol% inclusive, calculated as NiO.

[0224] The Ni-Cu-Zn ferrite material may further contain additives such as Co, Bi, Sn, and Mn.

[0225] The Ni—Cu—Zn ferrite material may further contain inevitable impurities.

[0226] <Green sheet manufacturing process> First, a magnetic material, an organic binder such as polyvinyl butyral resin, an organic solvent such as ethanol or toluene, a plasticizer, etc. are mixed in a ball mill together with PSZ media, and then pulverized to produce a slurry.

[0227] Next, the slurry is formed into a sheet of a predetermined thickness by a doctor blade method or the like, and then punched into a predetermined shape to produce a green sheet. The thickness of the green sheet is, for example, 20 μm or more and 30 μm or less. The shape of the green sheet is, for example, rectangular.

[0228] As the material for the green sheets, instead of a magnetic material, a non-magnetic material such as borosilicate glass material may be used, or a mixed material of a magnetic material and a non-magnetic material may be used.

[0229] <Conductor pattern formation process> First, a via hole is formed by irradiating a predetermined portion of the green sheet with a laser.

[0230] Next, a conductive paste such as Ag paste is applied to the surface of the green sheet by screen printing or the like, filling the via holes. This forms via conductor patterns in the via holes of the green sheet, while forming coil conductor conductor patterns connected to the via conductor patterns on the surface. In this manner, a coil sheet is produced, with the coil conductor conductor patterns and via conductor patterns formed on the green sheet. Multiple coil sheets are produced, and each coil sheet is provided with a coil conductor conductor pattern corresponding to the coil conductor shown in FIGS. 2 and 3 and a via conductor pattern corresponding to the via conductor connected to the coil conductor shown in FIGS. 2 and 3 (including the lead-out via conductor Saa1 and lead-out via conductor Sab1 shown in FIGS. 2 and 3).

[0231] In addition, a conductive paste such as Ag paste is applied to the surface of the green sheet by screen printing or the like, filling the via holes. This forms via conductor patterns in the via holes of the green sheet, while forming land conductor patterns connected to the via conductor conductor patterns on the surface. In this way, via sheets, on which land conductor patterns and via conductor conductor patterns are formed on the green sheet, are produced separately from the coil sheet. Multiple via sheets are also produced, and on each via sheet, land conductor patterns corresponding to the lead lands constituting the lead conductors shown in FIGS. 2 and 3 and via conductor conductor patterns corresponding to the lead via conductors connected to the lead lands shown in FIGS. 2 and 3 (excluding the lead via conductors Saa1 and Sab1 shown in FIGS. 2 and 3) are formed.

[0232] When the coil sheet and the via sheet are produced, the maximum diameter of the conductor pattern for the via conductor, which will later become the lead-out via conductor, is set to be 100 μm or less after firing, which will be described later.

[0233] <Laminated block manufacturing process> The coil sheets and via sheets are stacked in the stacking direction (length direction L in FIGS. 2 and 3) in the order shown in FIGS. 2 and 3, and then thermocompression bonded to form a laminate block.

[0234] <Element and coil manufacturing process> First, the laminate block is cut into a predetermined size using a dicer or the like to produce individual chips.

[0235] Next, the individual chips are fired at a firing temperature of, for example, 900° C. to 920° C. for, for example, 2 hours to 4 hours.

[0236] When the individual chips are fired, the green sheets of the coil sheet and via sheet become insulating layers, resulting in an element body in which multiple insulating layers are stacked in the stacking direction (length direction L in Figures 2 and 3).

[0237] When the singulated chips are fired, the conductor patterns for the coil conductors and the conductor patterns for the via conductors of the coil sheet become coil conductors and via conductors (including the lead-out via conductors Saa1 and Sab1 shown in FIGS. 2 and 3), respectively. As a result, a coil is produced in which multiple coil conductors stacked in the stacking direction (the length direction L in FIGS. 2 and 3) are electrically connected via the via conductors.

[0238] In this way, the element body and the coil provided inside the element body are produced.

[0239] On the other hand, when the individual chips are fired, the land conductor patterns and via conductor conductor patterns of the via sheet become lead lands and lead via conductors, respectively. As a result, a first lead conductor, a second lead conductor, a third lead conductor, and a fourth lead conductor are produced, each formed by alternately connecting a plurality of lead lands and a plurality of lead via conductors stacked in the stacking direction (length direction L in Figures 2 and 3). The first lead conductor and the second lead conductor are exposed from a first end face of the element body. The third lead conductor and the fourth lead conductor are exposed from a second end face of the element body.

[0240] The element body may be subjected to barrel polishing, for example, to round the corners and ridges.

[0241] <External electrode formation process> First, a conductive paste such as a paste containing Ag and glass frit is applied to form a first coating film connected to the first and second extraction conductors exposed from the first end face of the element body, extending from the first end face of the element body over a portion of each of the first main surface, the second main surface, the first side surface, and the second side surface.

[0242] In addition, by applying a conductive paste such as a paste containing Ag and glass frit, a second coating film connected to the third and fourth extraction conductors exposed from the second end face of the element body is formed so as to extend from the second end face of the element body over a portion of each of the first main surface, the second main surface, the first side surface, and the second side surface.

[0243] In this way, the first coating film and the second coating film are formed at positions spaced apart from each other on the surface of the element body.

[0244] When forming the first coating film and the second coating film, the first coating film and the second coating film may be formed at different times or at the same time.

[0245] When the first coating film and the second coating film are formed at different times, they may be formed in the order of the first coating film and the second coating film, or the order of the second coating film and the first coating film.

[0246] Next, the first coating film is baked to form a first base electrode that extends from the first end face of the element body over a portion of each of the first main surface, the second main surface, the first side surface, and the second side surface, and is connected to the first extraction conductor and the second extraction conductor.

[0247] In addition, by baking the second coating film, a second base electrode is formed that extends from the second end face of the element body over a portion of each of the first main surface, the second main surface, the first side surface, and the second side surface, and is connected to the third extraction conductor and the fourth extraction conductor.

[0248] The baking temperature for the first coating film and the second coating film is, for example, 800°C or higher and 820°C or lower.

[0249] The thickness of the first and second base electrodes is, for example, 5 μm.

[0250] Then, a Ni-plated electrode and a Sn-plated electrode are formed in this order on the surface of the first base electrode by electrolytic plating, etc. This forms a first external electrode having the first base electrode, Ni-plated electrode, and Sn-plated electrode in this order from the surface side of the element body.

[0251] Furthermore, a Ni-plated electrode and a Sn-plated electrode are formed in this order on the surface of the second base electrode by electrolytic plating, etc. This forms a second external electrode having the second base electrode, the Ni-plated electrode, and the Sn-plated electrode in this order from the surface side of the element body.

[0252] In this way, a first external electrode electrically connected to the coil via the first and second lead conductors, and a second external electrode electrically connected to the coil via the third and fourth lead conductors are formed on the surface of the element body.

[0253] In this way, the multilayer coil component 1 is manufactured. [Example]

[0254] EXAMPLES Hereinafter, examples that specifically disclose the multilayer coil component of the present invention will be described, but the present invention is not limited to only the following examples.

[0255] [Example 1] The multilayer coil component of Example 1 was manufactured by the following method.

[0256] <Magnetic material manufacturing process> First, Fe2O3, ZnO, CuO, and NiO were weighed out to give a predetermined ratio.

[0257] Next, these weighed materials and pure water were mixed in a ball mill together with PSZ media and then pulverized. The mixing and pulverization time was set to 6 hours.

[0258] The resulting pulverized material was dried and then calcined at a temperature of 800° C. for 3 hours.

[0259] In this manner, a powdered magnetic material, more specifically, a powdered magnetic ferrite material was prepared.

[0260] <Green sheet manufacturing process> First, the magnetic material, polyvinyl butyral resin as an organic binder, ethanol and toluene as organic solvents, and a plasticizer were mixed in a ball mill together with PSZ media, and then pulverized to prepare a slurry.

[0261] Next, the slurry was formed into a sheet by a doctor blade method and then punched out to produce a green sheet. The thickness of the green sheet was set to 25 μm and the shape of the green sheet was set to a rectangular shape.

[0262] <Conductor pattern formation process> First, a via hole was formed by irradiating a predetermined portion of the green sheet with a laser.

[0263] Next, Ag paste was applied to the surface of the green sheet by screen printing, filling the via holes. As a result, via conductor patterns were formed in the via holes of the green sheet, and coil conductor patterns connected to the via conductor patterns were formed on the surface. In this way, a coil sheet was produced in which coil conductor patterns and via conductor patterns were formed on the green sheet. Multiple coil sheets were produced, and each coil sheet was provided with coil conductor patterns corresponding to the coil conductors shown in FIGS. 2 and 3 and via conductor patterns corresponding to the via conductors connected to the coil conductors shown in FIGS. 2 and 3 (including the lead-out via conductors Saa1 and Sab1 shown in FIGS. 2 and 3).

[0264] When the coil sheet was produced, the dimensions in the length direction and width direction of the conductor pattern for the coil conductor were set to 17.5 μm and 200 μm, respectively, after firing as described below.

[0265] In addition, Ag paste was applied to the surface of the green sheet by screen printing while filling the via holes. As a result, via conductor patterns were formed in the via holes of the green sheet, and land conductor patterns connected to the via conductor conductor patterns were formed on the surface. In this way, via sheets in which land conductor patterns and via conductor conductor patterns were formed on the green sheet were produced separately from the coil sheet. Multiple via sheets were also produced, and on each via sheet, land conductor patterns corresponding to the lead lands constituting the lead conductors shown in FIGS. 2 and 3 and via conductor conductor patterns corresponding to the lead via conductors connected to the lead lands shown in FIGS. 2 and 3 (excluding the lead via conductor Saa1 and lead via conductor Sab1 shown in FIGS. 2 and 3) were formed.

[0266] When the coil sheet and the via sheet were produced, the diameter of the conductor pattern for the via conductor, which would later become the lead-out via conductor, was set to 92 μm after firing, which will be described later.

[0267] <Laminated block manufacturing process> The coil sheets and via sheets were stacked in the stacking direction (length direction L in FIGS. 2 and 3) in the order shown in FIGS. 2 and 3, and then thermocompression bonded to form a laminate block.

[0268] <Element and coil manufacturing process> First, the laminate block was cut into a predetermined size with a dicer to produce individual chips.

[0269] Next, the individual chips were fired at a firing temperature of 900° C. for three hours.

[0270] When the individual chips were fired, the green sheets of the coil sheet and via sheet became insulating layers, resulting in an element body in which multiple insulating layers were stacked in the stacking direction (length direction L in Figures 2 and 3).

[0271] When the singulated chips were fired, the conductor patterns for the coil conductors and the conductor patterns for the via conductors of the coil sheet became coil conductors and via conductors (including the lead-out via conductors Saa1 and Sab1 shown in FIGS. 2 and 3), respectively. As a result, a coil was produced in which multiple coil conductors stacked in the stacking direction (the length direction L in FIGS. 2 and 3) were electrically connected via the via conductors.

[0272] In this way, the element body and the coil provided inside the element body were produced.

[0273] On the other hand, when the individual chips were fired, the land conductor patterns and via conductor conductor patterns of the via sheet became lead lands and lead via conductors, respectively. As a result, a first lead conductor, a second lead conductor, a third lead conductor, and a fourth lead conductor were produced, each formed by alternately connecting multiple lead lands and multiple lead via conductors stacked in the stacking direction (length direction L in Figures 2 and 3). The first and second lead conductors were exposed from the first end face of the element body. The third and fourth lead conductors were exposed from the second end face of the element body.

[0274] The element body was then placed together with media in a rotary barrel machine, and barrel polishing was performed on the element body to round the corners and ridges.

[0275] <External electrode formation process> First, a conductive paste containing Ag and glass frit was applied to form a first coating film connected to the first and second extraction conductors exposed from the first end face of the element body, extending from the first end face of the element body over a portion of each of the first main surface, the second main surface, the first side surface, and the second side surface.

[0276] In addition, by applying a conductive paste containing Ag and glass frit, a second coating film connected to the third and fourth extraction conductors exposed from the second end face of the element body was formed so as to extend from the second end face of the element body over a portion of each of the first main surface, the second main surface, the first side surface, and the second side surface.

[0277] In this way, the first coating film and the second coating film were formed at positions spaced apart from each other on the surface of the element body.

[0278] Next, the first coating film was baked to form a first base electrode that extended from the first end face of the element body over a portion of each of the first main surface, the second main surface, the first side surface, and the second side surface, and was connected to the first extraction conductor and the second extraction conductor.

[0279] In addition, by baking the second coating film, a second base electrode was formed that extended from the second end face of the element body over a portion of each of the first main surface, the second main surface, the first side surface, and the second side surface, and was connected to the third extraction conductor and the fourth extraction conductor.

[0280] The baking temperature for the first and second coating films was 800°C.

[0281] The thickness of the first and second base electrodes was set to 5 μm.

[0282] Then, a Ni-plated electrode and a Sn-plated electrode were formed in this order on the surface of the first base electrode by electrolytic plating, thereby forming a first external electrode having the first base electrode, Ni-plated electrode, and Sn-plated electrode in this order from the surface side of the element body.

[0283] Furthermore, a Ni-plated electrode and a Sn-plated electrode were formed in this order on the surface of the second base electrode by electrolytic plating, thereby forming a second external electrode having the second base electrode, Ni-plated electrode, and Sn-plated electrode in this order from the surface side of the element body.

[0284] In this way, a first external electrode electrically connected to the coil via the first and second lead conductors, and a second external electrode electrically connected to the coil via the third and fourth lead conductors were formed on the surface of the element body.

[0285] In this manner, the multilayer coil component 1 of Example 1 was manufactured.

[0286] The laminated coil component of Example 1 had a lengthwise dimension of 2.0 mm, a heightwise dimension of 1.25 mm, and a widthwise dimension of 1.25 mm.

[0287] In the multilayer coil component of Example 1, the diameters of the extraction via conductors constituting the first, second, third, and fourth extraction conductors were all 92 μm. That is, in the multilayer coil component of Example 1, the sum of the cross-sectional areas of the extraction via conductors constituting the first extraction conductor and the extraction via conductors constituting the second extraction conductor, determined by the same first cross section along the height direction and width direction, was approximately 13,300 μm. 2 In addition, in the multilayer coil component of Example 1, the sum of the cross-sectional areas of the extraction via conductors constituting the third extraction conductor and the extraction via conductors constituting the fourth extraction conductor, which are determined by the same first cross section along the height direction and width direction, was approximately 13,300 μm 2 It was.

[0288] In the laminated coil component of Example 1, the lengthwise dimension of all the coil conductors was 17.5 μm, and the widthwise dimension of all the coil conductors was 200 μm. That is, in the laminated coil component of Example 1, the total cross-sectional area of ​​the three coil conductors constituting the parallel running section, which is determined by the same second cross section along the lengthwise and widthwise directions, was 10,500 μm. 2 It was.

[0289] From the above, in the multilayer coil component of Example 1, the sum of the cross-sectional areas of the extraction via conductors constituting the first extraction conductor and the extraction via conductors constituting the second extraction conductor, determined on the same first cross section, was equal to or greater than the sum of the cross-sectional areas of the three coil conductors constituting the parallel running section, determined on the same second cross section. Also, in the multilayer coil component of Example 1, the sum of the cross-sectional areas of the extraction via conductors constituting the third extraction conductor and the extraction via conductors constituting the fourth extraction conductor, determined on the same first cross section, was equal to or greater than the sum of the cross-sectional areas of the three coil conductors constituting the parallel running section, determined on the same second cross section.

[0290] [Comparative Example 1] The multilayer coil component of Comparative Example 1 was manufactured in the same manner as the multilayer coil component of Example 1, except that the second lead conductor and the fourth lead conductor were not fabricated.

[0291] In the multilayer coil component of Comparative Example 1, the diameters of the extraction via conductors constituting the first extraction conductor and the third extraction conductor were all 130 μm. That is, in the multilayer coil component of Comparative Example 1, the cross-sectional area of ​​the extraction via conductor constituting the first extraction conductor, determined by the first cross section along the height direction and width direction, was approximately 13,300 μm. 2 In the multilayer coil component of Comparative Example 1, the cross-sectional area of ​​the extraction via conductor constituting the third extraction conductor, which is determined by the first cross section along the height direction and width direction, was approximately 13,300 μm 2 It was.

[0292] In the multilayer coil component of Comparative Example 1, all of the coil conductors had a lengthwise dimension of 17.5 μm and a widthwise dimension of 200 μm, similar to the multilayer coil component of Example 1. That is, in the multilayer coil component of Comparative Example 1, similar to the multilayer coil component of Example 1, the total cross-sectional area of ​​the three coil conductors constituting the parallel running section, as determined by the same second cross section along the lengthwise and widthwise directions, was 10,500 μm. 2 It was.

[0293] [evaluation] First, the laminated coil component of Example 1 and the laminated coil component of Comparative Example 1 were each vertically stood with the second main surface of the element body exposed upward, and the periphery was sealed with resin. Then, each laminated coil component was polished with a polisher in the height direction from the second main surface side to the first main surface side of the element body until the lead conductors were exposed. Thereafter, the lead conductors in cross sections along the length and width directions of each laminated coil component were observed with a digital microscope.

[0294] In the multilayer coil component of Example 1, in which the diameter of the extraction via conductors was 100 μm or less, the exposed portions of the first and second extraction conductors exposed from the first end face of the element body were not significantly recessed relative to the surrounding insulating layer, and the occurrence of poor appearance due to the recesses in the exposed portions of the extraction conductors was suppressed. Also, in the multilayer coil component of Example 1, the exposed portions of the third and fourth extraction conductors exposed from the second end face of the element body were not significantly recessed relative to the surrounding insulating layer, and the occurrence of poor appearance due to the recesses in the exposed portions of the extraction conductors was suppressed.

[0295] Furthermore, in the laminated coil component of Example 1, in which the sum of the cross-sectional areas of the extraction via conductors constituting the first extraction conductor and the extraction via conductors constituting the second extraction conductor, as determined on the same first cross section, is equal to or greater than the sum of the cross-sectional areas of the three coil conductors constituting the parallel sections, as determined on the same second cross section, it was confirmed that the current density per extraction conductor was sufficiently low.

[0296] On the other hand, in the multilayer coil component of Comparative Example 1, in which the diameter of the extraction via conductor was greater than 100 μm, the exposed portion of the first extraction conductor exposed from the first end face of the element body was significantly recessed relative to the surrounding insulating layer, and the occurrence of poor appearance due to the recess in the exposed portion of the extraction conductor was not suppressed. Also, in the multilayer coil component of Comparative Example 1, the exposed portion of the third extraction conductor exposed from the second end face of the element body was significantly recessed relative to the surrounding insulating layer, and the occurrence of poor appearance due to the recess in the exposed portion of the extraction conductor was not suppressed. [Explanation of symbols]

[0297] 1. Multilayer coil components 10A Base 11a: first end surface of element body 11b: second end surface of element body 12a First principal surface of element 12b Second principal surface of the element 13a First side of the body 13b Second side of the body 21 1st external electrode 22 2nd external electrode 30A coil 41 First lead-out conductor 42 Second lead-out conductor 43 Third lead conductor 44 4th lead conductor C Coil shaft Ea1 First lamination section Fa1 Second lamination section L lengthwise Ma1 1st parallel section Na1 2nd parallel running section P1, P2, P3, P4, P5, P6, P7, P8, P9, P10, P11, P12, P13, P14, P15, Px, Py insulating layer Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8, Q9, Q10, Q11, Q12, Q13, Q14, Q15 Coil conductor Ra1, Rb1, Ra2, Rc2, Ra3, Rd3, Ra4, Rb4, Rb5, Rc5, Rc6, Rd6, Ra7, Rd7, Ra8, Rb8, R b9, Rc9, Rc10, Rd10, Ra11, Rd11, Ra12, Rb12, Rb13, Rc13, Rb14, Rd14, Ra15, Rb15 land part Rax, Rby drawer land Sa2, Sb2, Sa3, Sb3, Sc3, Sb4, Sc4, Sd4, Sa5, Sc5, Sd5, Sa6, Sb6, Sd6, Sa7, Sb7, Sc7, Sb8, Sc8, Sd8, Sa9, Sc9, Sd9, Sa10, Sb10, Sd10, Sa11, Sb11, Sc11, Sb12, Sc12, Sd12, Sa13, Sc13, Sd13, Sa14, Sb14, Sd14, Sa15, Sb15 via conductor Saa1, Sab1, Saax, Sabx, Sbay, Sbby via conductor for extraction T Height direction Ub2, Ub3, Uc3, Uc4, Ud4, Ua5, Ud5, Ua6, Ub6, Ub7, Uc7, Uc8, Ud8, Ua9, Ud9, Ua10, Ub10, Ub11, Uc11, Uc12, Ud12, Ua13, Ud13, Ua14 bend W width direction

Claims

1. an element body formed by laminating a plurality of insulating layers in a lamination direction; a coil provided inside the element body; an external electrode provided on a surface of the element body and electrically connected to the coil; the coil is formed by a plurality of coil conductors stacked in the stacking direction, which are electrically connected to each other through via conductors that pass through the insulating layers in the stacking direction; the plurality of coil conductors stacked in the stacking direction include a stacked portion made up of a plurality of adjacent coil conductors, the laminated portion has a parallel running section in which all of the coil conductors constituting the laminated portion overlap when viewed from the lamination direction, the parallel running sections are connected in parallel by the via conductors, the coil is electrically connected to the same external electrode via a plurality of lead conductors; each of the lead conductors includes a lead via conductor that penetrates the insulating layer in the stacking direction; The diameter of the lead-out via conductor is 100 μm or less, the plurality of coil conductors stacked in the stacking direction include an outermost coil conductor located at an outermost position in the stacking direction, The laminated coil component, wherein the length of the outermost coil conductor among the plurality of coil conductors is shorter than the lengths of the coil conductors other than the outermost coil conductor.

2. 2. The multilayer coil component according to claim 1, wherein, when a first cross section perpendicular to the direction in which the lead conductor extends and a second cross section perpendicular to the direction in which the coil conductor extends are defined, a total cross-sectional area of ​​the lead via conductors constituting the plurality of lead conductors connected to the same external electrode, defined in the same first cross section, is equal to or greater than a total cross-sectional area of ​​the coil conductors constituting the parallel-running sections, defined in the same second cross section.

3. 3. The multilayer coil component according to claim 1, wherein the multilayer portion is made up of three or more of the coil conductors.

4. 4. The multilayer coil component according to claim 1, wherein the stacking direction and the direction of the coil axis of the coil are parallel to the mounting surface of the element body along the same direction.

5. 5. The multilayer coil component according to claim 1, wherein the length of all of the coil conductors constituting the multilayer portion is a length of 3 / 4 turns of the coil.

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