Lamination coil component and manufacturing method of lamination coil component

Abstract

To provide a lamination coil component capable of suppressing a structural defect of an external electrode by reducing a coil trace of an element assembly end surface.SOLUTION: A lamination coil component 1 comprises: a lamination body 10 that is formed by laminating a plurality of insulation layers 31, and includes a coil 30 inside; and a first external electrode 21 and a second external electrode 22 that are connected to the coil. In the coil, a plurality of coil conductors 32 laminated with the insulation layer are connected, and the lamination body includes: a first end surface 11 and a second end surface 12 in a length direction L; a first principal surface 13 and a second principal surface 14 in a height direction T; and a first side surface and a second side surface in a width direction W. A coil shaft A is parallel to the first principal surface. The lamination body is further laminated with the insulation layer. A dimension in a direction vertical to the coil shaft includes plate-like members 37e and 37f that are larger than a dimension in a direction that is parallel to the coil shaft. An area of the plate-like member is smaller than an area of the first end surface of the lamination body.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a multilayer coil component and a method for manufacturing the multilayer coil component.

Background Art

[0002] Patent Document 1 discloses a method for manufacturing a multilayer coil component by laminating a plurality of ceramic green sheets having a conductor pattern serving as a coil conductor printed on the surface to produce an element having a built-in coil, and forming external electrodes on both end faces in the lamination direction of the element.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when forming external electrodes on a laminate manufactured by the method described in Patent Document 1, under specific conditions, poor formation of the external electrodes may occur.

[0005] When manufacturing a multilayer coil component by the method described in Patent Document 1, among the end faces in the lamination direction of the element, there may be a case where a portion where the circumferential shape of the coil overlaps protrudes, and relatively, the inner portion of the circumferential shape of the coil is recessed. A portion where the portion overlapping the circumferential shape of the coil protrudes more than the surroundings, which occurs in such a case, is also referred to as a "coil mark".

[0006] When a "coil mark" occurs on the end face where the external electrode of the element is formed, it is considered that when applying the paste for the external electrode to the end face of the element, air bubbles enter the recess in the center of the coil mark, leading to poor formation of the external electrode.

[0007] However, in conventional laminated coil components, it was not known that coil marks would cause defective formation of external electrodes.

[0008] The coil marks are formed on the end faces of the element in the stacking direction, but in Patent Document 1, the external electrodes are formed on end faces other than the end faces of the element in the stacking direction. Therefore, when the end face on which the coil marks are formed is different from the end face on which the external electrodes are formed, defects in the formation of the external electrodes did not occur.

[0009] Furthermore, depending on the size (depth) of the coil mark, it does not cause defective formation of the external electrodes. In conventional laminated coil components, the coil marks are small, and even when the paste that will become the external electrodes is applied to the end faces of the element, air bubbles do not get into the depression in the center of the coil marks.

[0010] However, when the size of the elements is increased or the number of layers of the coil conductor is increased in order to improve the performance of the multilayer coil component, it has been found that the depth of the coil marks increases (deepens), and when a paste to become the external electrodes is applied, air bubbles may get into the depression in the center of the coil marks, causing defects in the formation of the external electrodes.

[0011] In view of the above, poor formation of external electrodes due to coil marks is a problem that occurs significantly when the following conditions are met: the size of a multilayer coil component is large or the number of layers of a coil conductor is large, which causes the depth of the coil marks to increase; and the end face where the coil marks occur coincides with the end face where the external electrodes are formed. This problem has not been generally recognized until now.

[0012] The present invention has been made to solve the above problems, and has an object to provide a laminated coil component that can suppress structural defects in external electrodes by reducing coil marks on end faces of the element body. [Means for solving the problem]

[0013] The laminated coil component of the present invention includes a laminate formed by laminating a plurality of insulating layers and having a coil inside, and a first external electrode and a second external electrode electrically connected to the coil. The coil is formed by electrically connecting a plurality of coil conductors laminated together with the insulating layers. The laminate has a first end face and a second end face facing each other in the length direction, a first main face and a second main face facing each other in the height direction orthogonal to the length direction, and a first side face and a second side face facing each other in the width direction orthogonal to the length direction and the height direction. The coil axis of the coil is parallel to the first main face. The laminate further has a plate-like member laminated together with the insulating layers, the dimension of the plate-like member in the direction perpendicular to the coil axis being larger than the dimension in the direction parallel to the coil axis, and the area of the plate-like member being smaller than the area of the first end face of the laminate.

Advantages of the Invention

[0014] According to the present invention, it is possible to provide a laminated coil component capable of suppressing structural defects of the external electrodes by reducing coil marks on the body end face.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

BEST MODE FOR CARRYING OUT THE INVENTION

[0016] Hereinafter, the laminated coil component of the present invention will be described. Note that the present invention is not limited to the following configuration and may be appropriately changed without departing from the gist of the present invention. Also, a combination of a plurality of the individual preferred configurations described below is also within the scope of the present invention.

[0017] The drawings shown below are schematic diagrams, and their dimensions, scales of aspect ratios, etc. may be different from those of actual products. In the drawings, the same or corresponding parts will be denoted by the same reference numerals. Also, in each figure, the same elements will be denoted by the same reference numerals and redundant explanations will be omitted.

[0018] In this specification, terms indicating the relationship between elements (e.g., "parallel", "orthogonal", etc.) and terms indicating the shape of elements do not only mean the exact strict aspect, but also mean a substantially equivalent range, for example, a range including a difference of about several percent.

[0019] Each of the embodiments shown below is illustrative, and it goes without saying that partial substitution or combination of the configurations shown in different embodiments is possible. In the following embodiments from the second embodiment onwards, the description of matters common to the first embodiment will be omitted, and only the differences will be explained. In particular, for the same effects obtained by the same configurations, they will not be sequentially mentioned for each embodiment.

[0020] [Stacked coil component] The stacked coil component of the present invention includes a laminate in which a plurality of insulating layers are laminated and which has a coil inside, and a first external electrode and a second external electrode that are electrically connected to the coil. The coil is formed by electrically connecting a plurality of coil conductors laminated together with the insulating layers. The laminate has a first end face and a second end face facing each other in the length direction, a first main face and a second main face facing each other in the height direction orthogonal to the length direction, and a first side face and a second side face facing each other in the width direction orthogonal to the length direction and the height direction. The coil axis of the coil is parallel to the first main face. The laminate further has a plate-like member laminated together with the insulating layers, and the dimension in the direction perpendicular to the coil axis is larger than the dimension in the direction parallel to the coil axis. The area of the plate-like member is smaller than the area of the first end face of the laminate.

[0021] FIG. 1 is a perspective view schematically showing an example of the stacked coil component of the present invention. The stacked coil component 1 shown in FIG. 1 includes a laminate (element body) 10 and a first external electrode 21 and a second external electrode 22 provided on the outer surface of the laminate 10. The laminate 10 has a rectangular parallelepiped shape with six faces. The configuration of the laminate 10 will be described later, but a plurality of insulating layers and a plurality of coil conductors are laminated in the lamination direction and have a coil inside. The first external electrode 21 and the second external electrode 22 are each electrically connected to the coil.

[0022] In the laminated coil component and the laminate in this specification, the length direction, the height direction, and the width direction are the L direction, the T direction, and the W direction in FIG. 1. Here, the length direction L, the height direction T, and the width direction W are orthogonal to each other. Here, the length direction L is a direction parallel to the lamination direction.

[0023] As shown in FIG. 1, the laminate 10 has a first end face 11 and a second end face 12 facing each other in the length direction L, a first main face 13 and a second main face 14 facing each other in the height direction T orthogonal to the length direction L, and a first side face 15 and a second side face 16 facing each other in the width direction W orthogonal to the length direction L and the height direction T.

[0024] Although not shown in FIG. 1, it is preferable that the corners and ridge lines of the laminate 10 are rounded. A corner is a portion where three faces of the laminate intersect, and a ridge line portion is a portion where two faces of the laminate intersect.

[0025] The first external electrode 21 covers, for example, as shown in FIG. 1, the entire first end face 11 of the laminate 10 and extends from the first end face 11 to cover a part of the first main face 13, a part of the second main face 14, a part of the first side face 15, and a part of the second side face 16.

[0026] The second external electrode 22 covers, for example, as shown in FIG. 1, the entire second end face 12 of the laminate 10 and extends from the second end face 12 to cover a part of the first main face 13, a part of the second main face 14, a part of the first side face 15, and a part of the second side face 16.

[0027] When mounting the laminated coil component 1 in which the first external electrode 21 and the second external electrode 22 are arranged as described above on a substrate, any one of the first main face 13, the second main face 14, the first side face 15, and the second side face 16 of the laminate 10 becomes the mounting face.

[0028] However, the first external electrode 21 only needs to extend from at least a part of the first end face 11 of the laminate 10 to the mounting face of the laminate 10.

[0029] Similarly, the second external electrode 22 may extend from at least a part of the second end face 12 of the laminate 10 over the mounting surface of the laminate 10.

[0030] The first external electrode 21 and the second external electrode 22 may each have a single-layer structure or a multi-layer structure.

[0031] 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, alloys containing at least one of these metals, and the like.

[0032] 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 laminate 10, for example, a base electrode layer containing Ag, a Ni film, and a Sn film.

[0033] The size of the laminated coil component of the present invention is not particularly limited, but it is preferably 1608 size or more in JIS C 5101-21(2021) (however, the symbol M indicating that the dimensions are expressed in the metric system is omitted).

[0034] FIG. 2 is an exploded perspective view schematically showing an example of the laminate constituting the laminated coil component shown in FIG. 1.

[0035] As shown in FIG. 2, the laminate 10 is configured by laminating a plurality of insulating layers 31a, 31b, 31c, 31d, 31e, 31f, 131e, and 131f in the lamination direction (here, the length direction L) from the second end face 12 side to the first end face 11 side of the laminate 10. Hereinafter, the insulating layers 31a, 31b, 31c, 31d, 31e, and 31f are also collectively referred to as the insulating layer 31. Also, the insulating layer 131e and the insulating layer 131f are also collectively referred to as the insulating layer 131.

[0036] In this specification, the direction in which a plurality of insulating layers constituting the laminate overlap is referred to as the lamination direction.

[0037] In FIG. 2, the insulating layers 31e and 131e are disposed on the lower side in the stacking direction (the second end face 12 side of the laminate 10), and the insulating layers 31f and 131f are disposed on the upper side in the stacking direction (the first end face 11 side of the laminate 10).

[0038] Examples of the constituent material of each insulating layer 31 include magnetic materials such as ferrite materials.

[0039] In the insulating layers 31a, 31b, 31c, and 31d, coil conductors 32a, 32b, 32c, and 32d and via conductors 33a, 33b, 33c, and 33d are provided, respectively. In the insulating layer 31e, a via conductor 33e and a land 35e are provided. In the insulating layer 31f, a via conductor 33f and a land 35f are provided. In the insulating layer 131e, a via conductor 33e, a land 35e, and a plate-like member 37e are provided. In the insulating layer 131f, a via conductor 33f, a land 35f, and a plate-like member 37f are provided. The total number of the insulating layers 131e and 131f may be 1 layer or 2 or more layers. The total number of the insulating layers 31e may be 0 layer, 1 layer, or 2 or more layers. The total number of the insulating layer 31e and the insulating layer 131e may be 1 layer or 2 or more layers. Similarly, the total number of the insulating layers 31f may be 0 layer, 1 layer, or 2 or more layers. The total number of the insulating layer 31f and the insulating layer 131f may be 1 layer or 2 or more layers. Hereinafter, the coil conductors 32a, 32b, 32c, and 32d are also collectively referred to as the coil conductor 32.

[0040] The coil conductors 32a, 32b, 32c, and 32d are provided on the main surfaces of the insulating layers 31a, 31b, 31c, and 31d, respectively, and are stacked together with the insulating layers 31a, 31b, 31c, 31d, 31e, 31f, 131e, and 131f. In FIG. 2, each coil conductor 32 has a 3 / 4 turn shape, and four insulating layers 31 arranged in the order of the insulating layers 31a, 31b, 31c, and 31d are used as one unit (for 3 turns) and are repeatedly stacked.

[0041] Further, the coil conductors 32a, 32b, 32c, and 32d each include an annular circumferential portion 34a, 34b, 34c, and 34d with one portion missing and a partial gap, and lands 35a, 35b, 35c, and 35d. Lands 35a, 35b, 35c, and 35d are provided at both ends of each circumferential portion 34a, 34b, 34c, and 34d, respectively. Hereinafter, the circumferential portions 34a, 34b, 34c, and 34d are also collectively referred to as the circumferential portion 34.

[0042] The via conductors 33a, 33b, 33c, 33d, 33e, and 33f are each provided so as to penetrate the insulating layers 31a, 31b, 31c, 31d, 31e, 31f, 131e, and 131f in the stacking direction. Hereinafter, the via conductors 33a, 33b, 33c, 33d, 33e, and 33f are also collectively referred to as the via conductor 33.

[0043] Lands 35e and 35f are provided directly above the via conductors 33e and 33f, respectively. The lands 35a, 35b, 35c, 35d, 35e, and 35f are preferably slightly larger than the line widths of the circumferential portions 34a, 34b, 34c, and 34d. Hereinafter, the lands 35a, 35b, 35c, 35d, 35e, and 35f are also collectively referred to as the land 35.

[0044] Examples of the constituent materials of each coil conductor 32 including the circumferential portion 34 and the land 35 and each via conductor 33 include Ag, Au, Cu, Pd, Ni, Al, and alloys containing at least one of these metals.

[0045] The plurality of insulating layers 31a, 31b, 31c, 31d, 31e, 31f, 131e, and 131f configured as described above are stacked in the stacking direction. Thereby, the laminate 10 is formed, and the plurality of coil conductors 32a, 32b, 32c, and 32d are electrically connected via the via conductors 33a, 33b, 33c, and 33d. As a result, a solenoid-shaped coil having a coil axis parallel to the stacking direction is formed within the laminate 10.

[0046] Also, via conductor 33e and land 35e serve as the second lead conductor within laminate 10 and are exposed at the second end face 12 of laminate 10. That is, the second lead conductor includes via conductor 33e and land 35e. As will be described later, the second lead conductor connects between the second external electrode 22 and the coil conductor 32a facing it within laminate 10.

[0047] Via conductor 33f and land 35f serve as the first lead conductor within laminate 10 and are exposed at the first end face 11 of laminate 10. That is, the first lead conductor includes via conductor 33f and land 35f. As will be described later, the first lead conductor connects between the first external electrode 21 and the coil conductor 32d facing it within laminate 10.

[0048] When viewed from the stacking direction (length direction L), it is preferable that the coil conductors 32 overlap each other. Also, when viewed from the stacking direction, the coil may have a shape composed of straight portions as shown in FIG. 2 (for example, a polygonal shape such as a rectangle), a shape composed of curved portions (for example, a circular shape), or a shape composed of straight portions and curved portions.

[0049] By laminating insulating layers 131e and 131f together with insulating layers 31a, 31b, 31c, 31d, 31e, and 31f, laminate 10 has plate-like members 37e and 37f. Hereinafter, plate-like members 37e and 37f are also collectively referred to as plate-like member 37.

[0050] Specifically, by laminating insulating layer 131e together with insulating layer 31e, plate-like member 37e is provided between the second end face 12 of laminate 10 and the coil conductor 32a closest to the second end face 12. Also, by laminating insulating layer 131f together with insulating layer 31f, plate-like member 37f is provided between the first end face 11 of laminate 10 and the coil conductor 32d closest to the first end face 11. The dimension of the plate-like member 37 in the direction perpendicular to the coil axis is larger than the dimension in the direction parallel to the coil axis. Therefore, it can be said that the shape of the plate-like member 37 is plate-like extending in the same direction as the insulating layer 131. Also, the plate-like member 37 covers only a part of the insulating layer 131. Therefore, the area of the plate-like member 37 is smaller than the area of the insulating layer 131 corresponding to the area of the first end face 11 or the second end face 12 of the laminate 10.

[0051] The area of the plate-like member is preferably 1.63 or less, more preferably 0.18 or more and 1.40 or less, when the cross-sectional area of the coil is taken as 1. Note that the area of the plate-like member is the area of the plate-like member when viewed from the coil axis direction. Also, when two or more plate-like members are provided, each plate-like member is measured and the average is regarded as the area of the plate-like member.

[0052] Note that the cross-sectional area of the coil is the area obtained from the shape of the inner part (inner contour) of the circumferential shape of the coil.

[0053] In the exploded perspective view of the laminate shown in FIG. 2, the distance between the coil conductors in the width direction W of the laminate 10 is the length indicated by R W and the distance between the coil conductors in the height direction T of the laminate 10 is the length indicated by R T The shapes of the plate-like members 37e and 37f as viewed from the lamination direction of the laminate 10 are such that the lengths in the height direction T and the width direction W of the laminate 10 are L W and L T respectively, and L W = L T forms a square. Also, the outer shape of the circumferential shape of the coil is a square with a length RT in the height direction T of the laminate 10 and a length RW in the width direction. Therefore, the area of the plate-like member is represented by L W 2 , L T 2 or L W × L T and the cross-sectional area of the coil is represented by R T × R W .

[0054] The area of the plate-like member may be 1 or less when the cross-sectional area of the coil is taken as 1. When the cross-sectional area of the plate-like member exceeds 1 when the cross-sectional area of the coil is taken as 1, the coil conductor constituting the coil and the plate-like member may partially overlap in the stacking direction, and there may be a case where the size of the coil mark cannot be made sufficiently small.

[0055] When looking through the laminate from the length direction, it is preferable that the outer shape of the plate-like member and the inner shape of the circumferential shape of the coil are similar. Since the coil mark is likely to be formed as a shape similar to the inner contour of the circumferential shape of the coil inside the circumferential shape of the coil, if the outer shape of the plate-like member and the inner shape of the circumferential shape of the coil are similar, it is easy to reduce the coil mark.

[0056] In the exploded perspective view of the laminate shown in FIG. 2, the inner shape of the circumferential shape of the coil is substantially square, and the outer shape of the plate-like member is also substantially square, so it can be said that the outer shape of the plate-like member and the inner shape of the circumferential shape of the coil are similar.

[0057] Also, regardless of the inner shape of the circumferential shape of the coil, the outer shape of the plate-like member does not have to be similar to the inner shape of the circumferential shape of the coil. For example, when the inner shape of the circumferential shape of the coil is substantially square, the outer shape of the plate-like member may be substantially circular, pentagonal, rectangular, or the like. In this way, by arbitrarily changing the outer shape of the plate-like member with respect to the inner shape of the circumferential shape of the coil, the size of the coil mark can be adjusted.

[0058] FIG. 3 is a side view schematically showing an example of the internal structure of the laminate constituting the laminated coil component shown in FIG. 1 in a perspective view.

[0059] As shown in FIG. 3, in the multilayer coil component 1, since a plurality of insulating layers 31 are laminated in the length direction L, the length direction L is the lamination direction. Further, the lamination direction of the laminate 10 and the coil axis A of the coil 30 are parallel to any one of the first main surface 13, the second main surface 14, the first side surface 15, or the second side surface 16, which is the mounting surface, for example, the first main surface 13.

[0060] As shown in FIG. 3, actually, no boundary is visible between adjacent insulating layers 31.

[0061] The first lead conductor 41 extends in the lamination direction within the laminate 10 and linearly connects between the first external electrode 21 provided on the first end face 11 and the coil conductor 32a facing the first external electrode 21. Similarly, the second lead conductor 42 extends in the lamination direction within the laminate 10 and linearly connects between the second external electrode 22 provided on the second end face 12 and the coil conductor 32d facing the second external electrode 22.

[0062] When viewed from the lamination direction (length direction L), it is preferable that the via conductors constituting the lead conductors overlap each other, but the via conductors constituting the lead conductors do not necessarily have to be strictly linearly arranged.

[0063] In FIGS. 2 and 3, the case where the number of laminations of the coil conductors 32 for forming three turns of the coil 30 is 4, that is, the case where the repeating shape is a 3 / 4 turn shape is illustrated, but the number of laminations of the coil conductors 32 for forming one turn of the coil 30 is not particularly limited. For example, the number of laminations of the coil conductors 32 for forming one turn of the coil 30 may be 2, that is, the repeating shape may be a 1 / 2 turn shape.

[0064] Also, the number of laminations of the coil conductors 32, that is, the total number of laminations of all the coil conductors 32 included in the laminate 10 is not particularly limited, but is preferably 30 or more and 120 or less. Since coil marks are likely to occur on the first end face of the laminate in which the total number of laminations of all the coil conductors included in the laminate is 50 or more, it is suitable for the multilayer coil conductor of the present invention.

[0065] FIG. 4 is a cross-sectional view schematically showing an example of a cross-section along line segment A1-A1 of the laminated coil component shown in FIG. 1.

[0066] As shown in FIG. 4, when looking at a cross-section in a direction perpendicular to the direction in which the coil conductor 32 extends, the cross-sectional shape of the coil conductor 32 is a flat shape (longitudinal shape), and its longitudinal direction is orthogonal to the lamination direction (length direction L). In the example shown in FIG. 4, the cross-sectional shape of the coil conductor 32 is an ellipse with the major axis orthogonal to the lamination direction, but the cross-sectional shape of the coil conductor 32 is not particularly limited, and for example, it may be a rectangular shape in which the lengths of a pair of opposite sides in the lamination direction are the same, or a trapezoidal shape in which the lengths of a pair of opposite sides in the lamination direction are different.

[0067] The laminate 10 shown in FIG. 4 has two plate-like members 37f between the first end face 11 of the laminate 10 and the coil conductor 32d closest to the first end face 11. This is because, as shown in FIG. 2, the insulating layer for forming the first lead conductor 41 includes the insulating layer 131f in which the via conductor 33f, the land 35f, and the plate-like member 37f are provided.

[0068] Since the laminate 10 has the plate-like member 37f, the shape of the first end face 11 of the laminate 10 can be adjusted. Specifically, due to the arrangement of the plate-like member 37f, the first recess 11a formed in the first end face 11 of the laminate 10 can be reduced by the thickness of the plate-like member 37f. Therefore, the depth d1 of the first recess 11a formed in the first end face 11 of the laminate 10 can be reduced as compared with the case where the plate-like member 37f is not arranged. Note that the depth d1 of the first recess 11a is the length from the deepest part 11a1 of the first recess 11a of the first end face 11 in the lamination direction to the apex 11b1 of the first convex part 11b which is the part where the first end face 11 protrudes. The first recess 11a shown in FIG. 4 is formed as a result of a coil mark being generated on the first end face 11 of the laminate 10. Since the coil mark is formed at a position overlapping the circumferential shape of the coil when the laminate 10 is viewed through in the length direction L, it can be said that the shape of the first recess 11a is a shape in which the inner part of the portion of the first end face 11 of the laminate 10 that overlaps the circumferential shape of the coil is recessed toward the second end face 12 side.

[0069] FIG. 4 is also a cross-sectional view obtained by cutting the center of the laminate 10 in the width direction W in a plane parallel to the length direction L and the height direction T of the laminate 10. The outer shape of the plate-like members 37e and 37f and the inner shape of the circumferential shape of the coil 30 may both be squares having equal dimensions in the height direction T and the width direction W. Therefore, in that case, the cross-sectional area of the coil 30 shown in FIG. 4 is R T 2 and the area of the plate-like members 37e and 37f is L T 2 From FIG. 4, R T > L T Therefore, when the cross-sectional area R of the coil 30 T 2 is taken as 1, it can be said that the area L of the plate-like members 37e and 37f T 2 is 1 or less.

[0070] The laminate 10 shown in FIG. 4 has one plate-like member 37e between the second end face 12 of the laminate 10 and the coil conductor 32a closest to the second end face 12. This is because, as shown in FIG. 2, the insulating layer for forming the second lead-out conductor 42 includes the insulating layer 131e in which the via conductor 33e, the land 35e, and the plate-like member 37e are provided.

[0071] Since the laminate 10 has the plate-like member 37e, the shape of the second end face 12 of the laminate 10 can be adjusted. Specifically, since the plate-like member 37e is disposed, the second recess 12a formed in the second end face 12 of the laminate 10 can be reduced by the thickness of the plate-like member 37. Therefore, the depth d2 of the second recess 12a formed in the second end face 12 of the laminate 10 can be reduced as compared with the case where the plate-like member 37e is not disposed. Note that the depth d2 of the second recess 12a is the length from the deepest part 12a1 of the second recess 12a of the second end face 12 in the stacking direction to the apex 12b1 of the second convex part 12b which is the part where the second end face 12 protrudes. The second recess 12a shown in FIG. 4 is formed as a result of a coil mark occurring on the second end face 12 of the laminate 10. Since the coil mark is formed at a position overlapping the circumferential shape of the coil when the laminate 10 is viewed through in the longitudinal direction L, it can be said that the shape of the second recess 12a is a shape in which the inner part of the portion of the second end face 12 of the laminate 10 overlapping the circumferential shape of the coil is recessed toward the first end face 11 side.

[0072] The shapes of the first end face and the second end face of the laminate in the case where the plate-like member is disposed and the case where it is not disposed will be described with reference to FIG. 5. FIG. 5 is a cross-sectional view schematically showing an example of a laminated coil component in which no plate-like member is disposed. The laminated coil component 1' shown in FIG. 5 is also an example in which the insulating layers 31e and 31f are used instead of the insulating layers 131e and 131f in the exploded perspective view of the laminated coil component shown in FIG. 2. That is, it is an example in which the laminate does not have the plate-like member 37.

[0073] As shown in FIG. 5, a first recess 11a' having a depth d1' is formed in the first end face 11' of the laminate 10' constituting the laminated coil component 1'. Further, a second recess 12a' having a depth d2' is formed in the second end face 12' of the laminate 10'. The depth d1' of the first recess 11a' formed on the first end face 11' of the laminate 10' constituting the multilayer coil component 1' is greater than the depth d1 of the first recess 11a formed on the first end face 11 of the laminate 10 constituting the multilayer coil component 1 shown in FIG. 4.

[0074] In the multilayer coil component 1' shown in FIG. 5, since the first recess 11a' on the first end face 11' is large, a gap 23' is formed between the first external electrode 21' and the first recess 11a'.

[0075] FIG. 6 is a side view of the multilayer coil component shown in FIG. 5 as viewed from the first end face side. As shown in FIG. 6, it can be seen that cracks 24' derived from the gap 23' shown in FIG. 5 have occurred on the surface of the first external electrode 21' formed on the first end face 11'.

[0076] On the other hand, as in the multilayer coil component 1 shown in FIG. 4, by providing the plate-like member 37 on the laminate 10, the recess formed on the first end face 11, which is the end face where the external electrode is formed, can be made smaller (shallower), and defective formation of the external electrode can be suppressed.

[0077] The depth of the recess on the first end face of the laminate and the depth of the recess on the second end face may be the same or different. However, the difference between the depth of the recess on the first end face and the depth of the recess on the second end face is preferably 12 μm or less. When the difference between the depth of the recess on the first end face and the depth of the recess on the second end face is 12 μm or less, variations in the shape of the first end face side and the shape of the second end face side of the multilayer coil component can be suppressed.

[0078] In the multilayer coil components shown in FIGS. 2 to 4, the difference between the depth d1 of the first recess on the first end face 11 and the depth d2 of the second recess on the second end face is preferably 12 μm or less.

[0079] Note that the depth of the first recess on the first end face is measured by a parallel dimension measuring tool or the like using the dimension difference between the location where the insulating layer is lowest (the most recessed location) and the location where it is highest (the most protruding location, i.e., corresponding to the apex of the first convex portion) in the length direction L in a cross-sectional image obtained using a digital microscope or the like after polishing the laminate from the main surface (LT surface) of the laminate to expose the LT cross-section up to the center in the width direction W. The depth of the second recess on the second end face can also be measured by the same procedure.

[0080] The plate-like member may be provided between the coil conductor closest to the first end face of the laminate and the first end face in the length direction of the laminate. When the plate-like member is provided between the coil conductor closest to the first end face of the laminate and the first end face, it is possible to effectively relieve the depth of the first recess while preventing the plate-like member from falling off the laminate. For example, in the laminated coil component 1 shown in FIGS. 2 to 4, the plate-like member 37f is provided between the coil conductor 32d closest to the first end face 11 of the laminate 10 and the first end face 11 of the laminate 10.

[0081] The plate-like member may be provided between the coil conductor closest to the second end face of the laminate and the second end face in the length direction of the laminate. For example, in the laminated coil component 1 shown in FIGS. 2 to 4, the plate-like member 37e is provided between the coil conductor 32a closest to the second end face 12 of the laminate 10 and the second end face 12 of the laminate 10.

[0082] The plate-like member is preferably provided at a position exposed from the first end face of the laminate. Note that "exposed from the first end face of the laminate" means exposed from the laminate, and does not necessarily mean that the plate-like member is exposed on the surface of the laminated coil component. That is, a part or all of the plate-like member exposed at the first end of the laminate may be covered by, for example, a first external electrode other than the laminate. In this case, it is preferable that the first external electrode covers at least a part of the plate-like member. The closer the plate-like member is disposed to the first end face of the laminate, the higher the effect of reducing coil marks. Therefore, when the plate-like member is provided at a position exposed on the first end face of the laminate, the effect of reducing coil marks by the plate-like member is particularly high. And when the first external electrode covers at least a part of the plate-like member, it becomes easier to suppress the occurrence of defective formation of the external electrode due to coil marks.

[0083] The plate-like member may be provided inside the coil. In this case, it is preferable that the area of the plate-like member in the height direction and the width direction is less than 1 when the cross-sectional area of the coil is set to 1. When the area of the plate-like member in the height direction and the width direction is less than 1 when the cross-sectional area of the coil is set to 1, when the laminate is viewed through in the length direction, the plate-like member can be arranged so as to fit inside the circumferential shape of the coil, so that the recess on the first end face of the laminate can be efficiently suppressed.

[0084] Two or more plate-like members may be provided. By changing the number of plate-like members, the size of the coil marks can be adjusted.

[0085] For example, in the laminate 10 constituting the laminated coil component 1 shown in FIGS. 2 to 4, a total of three plate-like members are provided. When two or more plate-like members are provided, the coil marks can be further suppressed as compared with the case where there is one plate-like member.

[0086] When two or more plate-like members are provided, at least one plate-like member is provided between the coil conductor closest to the first end face and the first end face in the length direction, and at least one plate-like member is provided between the coil conductor closest to the second end face and the second end face in the length direction, which is preferable. When the plate-like member is arranged at the above position, not only the first end face of the laminate but also the coil marks generated on the second end face can be suppressed.

[0087] For example, in the multilayer coil component 1 shown in FIGS. 2 to 4, one plate-like member 37e is provided between the coil conductor 32a closest to the first end face 11 of the laminate 10 and the first end face 11 of the laminate 10, and two plate-like members 37f are provided between the coil conductor 32d closest to the second end face 12 of the laminate 10 and the second end face 12 of the laminate 10.

[0088] When two or more plate-like members are provided, when the laminate is bisected in the length direction and divided into a first end face side region and a second end face side region, it is preferable that at least one plate-like member is provided in both the first end face side region and the second end face side region. Also in this case, the number of plate-like members provided may be the same in the first end face side region and the second end face side region, but it is preferably different. The plate-like member disposed in the first end face side region is likely to contribute to reducing the coil mark on the first end face, and the plate-like member disposed in the second end face side region is likely to contribute to reducing the coil mark on the second end face. Therefore, when two or more plate-like members are provided at the above positions, not only the first end face of the laminate but also the coil mark generated on the second end face can be suppressed. Also, in the step of laminating the insulating layers, it is common to laminate a plurality of insulating layers on the substrate so that the lamination direction is the same as the vertical direction. Either one of the first end face and the second end face on the substrate side is supported in a planar shape, and the other is not supported. From this, when the plate-like member is not arranged, only one end face is pressed against the substrate, and the depth of the coil mark may become asymmetric between the first end face and the second end face of the laminate. Therefore, if the number of plate-like members provided is different between the first end face side region and the second end face side region, the depth of the dent on the first end face and the depth of the dent on the second end face can be made smaller correspondingly, so that the difference in the size of the dents between the first end face and the second end face of the laminate can be made smaller.

[0089] For example, in the multilayer coil component 1 shown in FIGS. 2 to 4, among the eight insulating layers 31a, 31b, 31c, and 31d stacked, the fourth insulating layer 31d from the bottom and those disposed below this insulating layer 31d can be said to belong to the region on the first end face 11 side of the laminate 10. Similarly, among the eight insulating layers 31a, 31b, 31c, and 31d stacked, the fifth insulating layer 31a from the bottom and those disposed above this insulating layer 31a can be said to belong to the region on the second end face 12 side of the laminate 10. Therefore, in the multilayer coil component 1 shown in FIGS. 2 to 4, it can be said that one plate-like member 37e is provided in the region on the first end face 11 side, and two plate-like members 37f are provided in the region on the second end face 12 side, and it can be said that the number of plate-like members provided in the region on the first end face side is different from the number of plate-like members provided in the region on the second end face side.

[0090] The thickness per plate-like member is preferably 15 μm or more and 40 μm or less. Preferably, the total thickness of the plate-like members located in each of the regions on the first end face side and the second end face side, with the center in the stacking direction of the laminate as a boundary, is 20 μm or more and 150 μm or less. Also, in the stacking direction, the total thickness of the plate-like members provided in the region on the first end face side from the coil conductor closest to the first end face, and the total thickness of the plate-like members provided on the second end face side from the coil conductor closest to the second end face are each preferably 20 μm or more and 150 μm or less.

[0091] The material of the plate-like member is not particularly limited, but it is preferably made of an inorganic material. When the plate-like member is included in the laminate, using a plate-like member made of an inorganic material results in a small volume change during firing and facilitates adjustment of the dents caused by the plate-like member. Also, when exposing from the laminate, it is conceivable to provide the plate-like member after firing the laminate, and an organic material may be used. However, since inorganic materials generally have higher heat resistance and chemical resistance, it is preferably made of an inorganic material. Examples of the inorganic material include ceramic materials and metal materials.

[0092] Examples of the ceramic material include crystalline materials such as ferrite, alumina, and zirconia materials, amorphous materials such as borosilicate glass materials, and glass ceramics.

[0093] Examples of the metal material include Ag, Au, Cu, Pd, Ni, Al, and alloys containing at least one of these metals. Further, for example, as an inorganic material such as a ceramic material or a metal material, by using a material (for example, alumina or Cu) that is less expensive than the metal material (for example, Ag) constituting the internal electrode (coil conductor), the cost for reducing coil marks can be suppressed.

[0094] The plate-like member preferably contains the same metal element as the coil.

[0095] The plate-like member may be made of metal and may be electrically connected to the coil. When the plate-like member is made of metal and is electrically connected to the coil, the capacitance of the multilayer coil component can be adjusted by the plate-like member. Specifically, when the plate-like member is made of metal and is electrically connected to the coil, capacitances are generated between the plate-like member and the coil, and between the plate-like member and the external electrode. Further, when two or more plate-like members made of metal are provided, a capacitance is also generated between the plate-like members. Since these act as series capacitors, the capacitance of the entire multilayer coil component decreases. As a result, the impedance value at frequencies equal to or higher than the self-resonant frequency increases.

[0096] Note that the plate-like member may be directly connected to the coil or the land, or may be connected to the coil via a via conductor. For example, as shown in FIGS. 7 and 8 described later, a part of the land may be integrated with the plate-like member. Further, although not shown, the entire land may be integrated with the plate-like member. Note that when the plate-like member is integrated with the land provided in the same layer, the area of the land is also included in the calculation of the area of the plate-like member.

[0097] FIG. 7 is a developed view schematically showing another example of the laminate constituting the laminated coil component of the present invention. The developed view shown in FIG. 7 is obtained by increasing the area of the plate-like member from the developed view shown in FIG. 2. Specifically, in the laminate 10 shown in FIG. 2, the dimension in the height direction T is L T , and the dimension in the width direction W is L W . The insulating layers 131e and 131f having the plate-like members 37e and 37f are, in the laminate 100 shown in FIG. 7, the insulating layers 231e and 231f having the plate-like members 137e and 137f with the dimension in the height direction T being L 1T and the dimension in the width direction W being L 1W , respectively. The dimension L in the height direction of the plate-like members 137e and 137f 1T is larger than the dimension R in the height direction T of the inner contour shape of the circumferential shape of the coil. Similarly, the dimension L in the width direction W of the plate-like members 137e and 137f T is larger than the dimension R in the width direction W of the inner contour shape of the circumferential shape of the coil. 1W W Therefore, it can be said that a part of the lands 35e and 35f is integrated with the plate-like members 137e and 137f. In this case, the areas of the lands 35e and 35f are also included in the areas of the plate-like members 137e and 137f.

[0098] FIG. 8 is a side view schematically showing an example of the internal structure of the laminate shown in FIG. 7 in a perspective view. As shown in FIG. 8, the laminate 100 has the same configuration as the laminate 10 shown in FIG. 3, except that the size of the plate-like member is increased and a part of the land is integrated. The plate-like members 137e and 137f are made of metal. In this case, the plate-like members 137e and 137f are electrically connected to the lands 35e and 35f and the via conductors 33e and 33f, respectively. Also, it can be said that the plate-like members 137e and 137f are electrically connected to the coil 30 via the lands 35e and 35f and the via conductors 33e and 33f.

[0099] In addition, when the size of the plate-like member becomes larger than that in FIGS. 7 and 8 and the outer shape of the land cannot be confirmed, the land is regarded as being completely integrated with the plate-like member.

[0100] Further, the plate-like member made of a conductive metal may not be electrically connected to the coil. When the plate-like member made of a conductive metal is not electrically connected to the coil, since the plate-like member functions as an iron core, the inductance of the laminated coil component can be adjusted by adjusting the magnetic permeability of the plate-like member.

[0101] The plate-like member preferably contains the same ceramic material as the insulating layer.

[0102] The plate-like member may have the same composition as the coil or the same composition as the insulating layer.

[0103] Examples of the material constituting the insulating layer include magnetic materials such as magnetic ferrite materials and non-magnetic materials such as borosilicate glass materials. Further, a magnetic material and a non-magnetic material may be used in combination. The ferrite material is preferably a Ni-Cu-Zn-based ferrite material.

[0104] The material constituting the coil conductor may be any conductive material, and examples thereof include Ag, Au, Cu, Pd, Ni, Al, and alloys containing at least one of these metals.

[0105] Hereinafter, another example of the structure of the laminate constituting the laminated coil component of the present invention will be described using an exploded perspective view similar to FIG. 2.

[0106] FIG. 9 is a developed view schematically showing another example of the laminate constituting the laminated coil component of the present invention. The laminate 101 shown in Fig. 9 corresponds to a structure in which, among the insulating layers constituting the laminate 10 shown in Fig. 2, the first insulating layer from the second end face 12 side among the four insulating layers 31e and 131e constituting the second lead conductor is changed from the insulating layer 31e to the insulating layer 131e, the second insulating layer from the second end face 12 side is changed from the insulating layer 131e to the insulating layer 31e, the first insulating layer 31f among the four insulating layers 31f and 131f constituting the first lead conductor is changed to the insulating layer 131f from the first end face 11 side, and the second and third insulating layers 131f from the first end face 11 side are changed to the insulating layer 31f. The plate-like member 37e is provided between the coil conductor 32a closest to the second end face 12 and the second end face 12. The plate-like member 37f is exposed on the first end face 11 of the laminate 10.

[0107] Fig. 10 is a developed view schematically showing still another example of the laminate constituting the laminated coil component of the present invention. The laminate 102 shown in Fig. 10 corresponds to a structure in which, among the insulating layers constituting the laminate 10 shown in Fig. 2, the first, second, seventh, and eighth insulating layers 31a, 31b, 31c, and 31d from the first end face 11 side are changed to the insulating layers 131a, 131b, 131c, and 131d, respectively. The insulating layer 131a is provided with a via conductor 33a, a land 35a, and a plate-like member 37a. The insulating layer 131b is provided with a via conductor 33b, a land 35b, and a plate-like member 37b. The insulating layer 131c is provided with a via conductor 33c, a land 35c, and a plate-like member 37c. The insulating layer 131d is provided with a via conductor 33d, a land 35d, and a plate-like member 37d. The four plate-like members 37a, 37b, 37c, and 37d are respectively provided inside the spiral forming the coil, that is, inside the coil.

[0108] Fig. 11 is a developed view schematically showing still another example of the laminate constituting the laminated coil component of the present invention. FIG. 11 shows an example in the case where plate-like members are provided on all of the insulating layers corresponding to the coil sheet. Therefore, two plate-like members 37a, 37b, 37c, and 37d are provided in the coil inside the laminate 103, respectively.

[0109] FIG. 12 is a developed view schematically showing still another example of the laminate constituting the laminated coil component of the present invention. FIG. 12 shows an example in the case where plate-like members are provided on all of the insulating layers corresponding to the via sheet. Therefore, four plate-like members 37e are provided between the coil conductor 32a closest to the second end face 12 of the laminate 104 and the second end face 12 of the laminate 104, and three plate-like members 37f are provided between the coil conductor 32d closest to the first end face 11 of the laminate 104 and the first end face 11 of the laminate 104. One plate-like member 37f is exposed on the first end face 11 of the laminate 104.

[0110] FIG. 13 is a developed view schematically showing still another example of the laminate constituting the laminated coil component of the present invention. FIG. 13 shows an example in the case where plate-like members are provided on all of the insulating layers constituting the laminate. Therefore, four plate-like members 37e are provided between the coil conductor 32a closest to the second end face 12 of the laminate 105 and the second end face 12 of the laminate 105, and three plate-like members 37f are provided between the coil conductor 32d closest to the first end face 11 of the laminate 105 and the first end face 11 of the laminate 105. One plate-like member 37f is exposed on the first end face 11 of the laminate 104, and two plate-like members 37a, 37b, 37c, and 37d are provided in the coil inside, respectively.

[0111] [Manufacturing Method of Laminated Coil Component] The manufacturing method of the laminated coil component of the present invention includes a step of preparing a ceramic green sheet containing a ceramic material, a printing step of printing a conductor paste that becomes a coil conductor layer and / or a via conductor on the ceramic green sheet, a step of laminating the ceramic green sheet on which the coil conductor layer is formed to produce an unfired laminate containing an unfired coil, and a step of firing the unfired laminate to produce a laminate, and further includes a step of providing a layer containing an inorganic material having an area smaller than that of the ceramic green sheet in the step of producing the unfired laminate or the printing step.

[0112] Hereinafter, an example of the manufacturing method of the laminated coil component of the present invention will be described.

[0113] <Fabrication of Magnetic Material> First, Fe2O3, ZnO, CuO, and NiO are weighed so as to have a predetermined ratio.

[0114] Next, these weighed substances, pure water, etc. are put into a ball mill together with PSZ (partially stabilized zirconia) media and mixed, and then pulverized. The mixing and pulverizing time is, for example, 4 hours or more and 8 hours or less.

[0115] Then, after drying the obtained pulverized material, it is calcined. The calcination temperature is, for example, 700°C or more and 800°C or less. The calcination time is, for example, 2 hours or more and 5 hours or less.

[0116] In this way, a powdery magnetic material, more specifically, a powdery magnetic ferrite material is produced.

[0117] The ferrite material is preferably a Ni-Cu-Zn based ferrite material.

[0118] When the total amount is 100 mol%, the Ni-Cu-Zn ferrite material preferably contains Fe in terms of Fe2O3 of 40 mol% or more and 49.5 mol% or less, Zn in terms of ZnO of 2 mol% or more and 35 mol% or less, Cu in terms of CuO of 6 mol% or more and 13 mol% or less, and Ni in terms of NiO of 10 mol% or more and 45 mol% or less.

[0119] The Ni-Cu-Zn ferrite material may further contain additives such as Co, Bi, Sn, and Mn.

[0120] The Ni-Cu-Zn ferrite material may further contain inevitable impurities.

[0121] <Step of preparing a ceramic green sheet> First, a ceramic material, an organic binder such as a polyvinyl butyral resin, an organic solvent such as ethanol and toluene, and a plasticizer are put into a ball mill together with PSZ media and mixed, and then pulverized to produce a slurry. As the ceramic material, the above-described magnetic material can be used.

[0122] Next, the slurry is formed into a sheet having a predetermined thickness by a doctor blade method or the like, and then punched into a predetermined shape to produce a ceramic green sheet. The thickness of the ceramic green sheet is, for example, 20 μm or more and 30 μm or less. The shape of the ceramic green sheet is, for example, rectangular.

[0123] As the material of the ceramic green sheet, instead of the magnetic material, a non-magnetic material such as a borosilicate glass material may be used, or a mixed material of the magnetic material and the non-magnetic material may be used.

[0124] First, laser irradiation is performed on a predetermined portion of the ceramic green sheet to form via holes.

[0125] <Printing process> Next, a conductive paste such as an Ag paste is applied to the surface of the ceramic green sheet while filling the via holes by a screen printing method or the like. Thereby, a conductor pattern for via conductors is formed in the via holes in the ceramic green sheet, and a conductor pattern for coil conductors connected to the conductor pattern for via conductors is formed on the surface. In this way, a coil sheet in which a conductor pattern for coil conductors and a conductor pattern for via conductors are formed on the ceramic green sheet is produced. In the coil sheet, a conductor pattern for coil conductors corresponding to the coil conductor 32 shown in FIG. 2 and a conductor pattern for via conductors corresponding to the via conductors 33 (excluding the via conductors 33e and 33f) shown in FIG. 2 are formed. Further, separately from the coil sheet, a via sheet in which a conductor pattern for via conductors corresponding to the via conductors 33e and 33f shown in FIG. 2 is formed is produced.

[0126] <Step of producing an unfired laminate> The coil sheet and the via sheet are laminated in the stacking direction (length direction L) in the order corresponding to FIG. 2, and then thermocompression bonded to produce an unfired laminate block.

[0127] <Step of providing a layer containing an inorganic material> The step of providing a layer containing an inorganic material is performed in the step of producing an unfired laminate or the printing step. The step of providing a layer containing an inorganic material may be a step of printing a paste containing an inorganic material on a part of the surface of the ceramic green sheet. The paste containing an inorganic material printed on a part of the surface of the ceramic green sheet is disposed in the unfired laminate by laminating the ceramic green sheet, and becomes a plate-like member by firing. That is, a plate-like member can be provided in the laminate by the step of printing a paste containing an inorganic material on a part of the surface of the ceramic green sheet. In addition, the timing of performing the step of printing a paste containing an inorganic material on a part of the surface of the ceramic green sheet is not particularly limited as long as it is during the printing process, and it may be performed simultaneously with the printing of the conductor pattern for the coil conductor and the conductor pattern for the via conductor, before the printing of the conductor pattern for the coil conductor and the conductor pattern for the via conductor, or after the printing of the conductor pattern for the coil conductor and the conductor pattern for the via conductor. In any case, it can be said that the step of printing a paste containing an inorganic material on a part of the surface of the ceramic green sheet is performed in the printing process.

[0128] At this time, the object to which the paste containing the inorganic material is printed may be a coil sheet or a via sheet. The paste containing the inorganic material is preferably printed in a region inside the circumferential shape of the coil.

[0129] In the step of providing a layer containing an inorganic material, the paste printed on a part of the surface of the ceramic green sheet may contain the same ceramic material as the ceramic green sheet or the same metal element as the conductor paste that becomes the coil conductor layer.

[0130] The step of providing a layer containing an inorganic material may be a step of laminating a solid plate-like member together with the ceramic green sheet in the step of manufacturing an unfired laminate. In the step of manufacturing an unfired laminate, by laminating a solid plate-like member together with the ceramic green sheet, a plate-like member can be provided in the fired laminate.

[0131] In the step of laminating a solid plate-like member together with the ceramic green sheet in the step of manufacturing an unfired laminate, the solid plate-like member may contain the same ceramic material as the ceramic green sheet or the same metal element as the conductor paste that becomes the coil conductor layer.

[0132] <Process for manufacturing a laminate and a coil> The laminated body block is cut into a predetermined size using a dicing saw or the like to produce diced chips.

[0133] Next, the diced chips are fired. The firing temperature is, for example, 900 °C or higher and 920 °C or lower. The firing time is, for example, 2 hours or longer and 4 hours or shorter.

[0134] When the diced chips are fired, the ceramic green sheets of the coil sheet and the via sheet become insulating layers.

[0135] Also, when the diced chips are fired, the conductor patterns for the coil conductors and the via conductors each become a coil conductor and a via conductor. As a result, a coil in which a plurality of coil conductors laminated together with an insulating layer are electrically connected via a via conductor is produced.

[0136] As described above, a laminated body in which a plurality of insulating layers are laminated in the stacking direction and a coil is incorporated inside is produced.

[0137] For the laminated body, for example, barrel polishing may be performed to round the corner portions and the ridge line portions.

[0138] <Formation step of external electrodes> First, a conductive paste layer is formed by applying a conductive paste such as a paste containing Ag and glass frit to the first end face and the second end face from which the coil is drawn out among the outer surfaces of the laminated body.

[0139] Next, the conductive paste layer is baked to form a base electrode of the external electrode. The baking temperature is, for example, 800 °C or higher and 820 °C or lower. The thickness of the base electrode is, for example, 5 μm.

[0140] Then, on the surface of the base electrode, an Ni-plated electrode and an Sn-plated electrode are sequentially formed by electrolytic plating or the like. Thereby, an external electrode having the base electrode, the Ni-plated electrode, and the Sn-plated electrode in this order is formed.

[0141] Thus, the multilayer coil component is manufactured.

[0142] The following matters are described in this specification.

[0143] The present disclosure (1) includes a laminate in which a plurality of insulating layers are laminated and has a coil inside, and a first external electrode and a second external electrode electrically connected to the coil. The coil is formed by electrically connecting a plurality of coil conductors laminated together with the insulating layer. The laminate has a first end face and a second end face facing each other in the length direction, a first main face and a second main face facing each other in the height direction orthogonal to the length direction, and a first side face and a second side face facing each other in the width direction orthogonal to the length direction and the height direction. The coil axis of the coil is parallel to the first main face. The laminate further has a plate-like member laminated together with the insulating layer, and the dimension in the direction perpendicular to the coil axis is larger than the dimension in the direction parallel to the coil axis. The laminated coil component has a plate-like member whose area is smaller than the area of the first end face of the laminate.

[0144] The present disclosure (2) is the laminated coil component according to the present disclosure (1), in which the area of the plate-like member is 1.63 or less when the cross-sectional area of the coil is 1.

[0145] The present disclosure (3) is the laminated coil component according to the present disclosure (1) or (2), in which the plate-like member is provided between the coil conductor closest to the first end face and the first end face in the length direction.

[0146] The present disclosure (4) is such that the plate-like member is provided at a position exposed from the first end face of the laminate, The laminated coil component according to the present disclosure (1) or (2), wherein the first external electrode covers at least a part of the plate-like member.

[0147] The present disclosure (5) is the laminated coil component according to the present disclosure (1) or (2), wherein the plate-like member is provided inside the coil.

[0148] The present disclosure (6) is a laminated coil component in any combination with any one of the present disclosures (1) to (5), wherein the plate-like member is made of an inorganic material.

[0149] The present disclosure (7) is a laminated coil component in any combination with any one of the present disclosures (1) to (6), wherein the plate-like member contains the same metal element as the coil.

[0150] The present disclosure (8) is a laminated coil component in any combination with any one of the present disclosures (1) to (6), wherein the plate-like member is made of metal and is electrically connected to the coil.

[0151] The present disclosure (9) is a laminated coil component in any combination with any one of the present disclosures (1) to (6), wherein the plate-like member contains the same ceramic material as the insulating layer.

[0152] The present disclosure (10) is a laminated coil component in any combination with any one of the present disclosures (1) to (9), wherein two or more plate-like members are provided.

[0153] The present disclosure (11) is such that at least one of the plate-like members is provided between the coil conductor closest to the first end face and the first end face in the length direction, The laminated coil component according to the present disclosure (10), wherein at least one of the plate-like members is provided between the coil conductor closest to the second end face and the second end face in the length direction.

[0154] The present disclosure (12) is the laminated coil component according to the present disclosure (10), wherein when the laminate is bisected in the longitudinal direction and divided into the region on the first end face side and the region on the second end face side, at least one of the plate-like members is provided in both the region on the first end face side and the region on the second end face side, and the number of the provided plate-like members is different between the region on the first end face side and the region on the second end face side.

[0155] The present disclosure (13) is the laminated coil component which is any combination of the present disclosures (1) to (12), wherein the difference between the depth of the recess on the first end face of the laminate and the depth of the recess on the second end face of the laminate is 12 μm or less.

[0156] The present disclosure (14) is the laminated coil component which is any combination of the present disclosures (1) to (13), wherein the area of the plate-like member is in the range of 0.18 or more and 1.40 or less when the cross-sectional area of the coil is 1.

[0157] The present disclosure (15) is when viewed through the laminate from the longitudinal direction, The present disclosure (14) is the laminated coil component which is any combination of the present disclosures (1) to (14), wherein the outer contour shape of the plate-like member and the inner contour shape of the circumferential shape of the coil are similar.

[0158] The present disclosure (16) includes a step of preparing a ceramic green sheet containing a ceramic material, a printing step of printing a conductor paste to be a coil conductor layer and / or a via conductor on the ceramic green sheet, a step of laminating the ceramic green sheet on which the coil conductor layer is formed to produce an unfired laminate containing an unfired coil, a step of firing the unfired laminate to produce a laminate, and further includes, a step of providing a layer containing an inorganic material having an area smaller than that of the ceramic green sheet in the step of producing the unfired laminate or the printing step. This is a method for manufacturing a laminated coil component.

[0159] The present disclosure (17) is a method for manufacturing a laminated coil component according to the present disclosure (16), wherein the step of providing the layer containing the inorganic material is a step of printing a paste containing the inorganic material on a part of the surface of the ceramic green sheet.

[0160] The present disclosure (18) is a method for manufacturing a laminated coil component according to the present disclosure (17), wherein the paste to be printed contains the same ceramic material as the ceramic green sheet.

[0161] The present disclosure (19) is a method for manufacturing a laminated coil component according to the present disclosure (17), wherein the paste to be printed contains the same metal element as the conductor paste that will become the coil conductor layer.

[0162] The present disclosure (20) is a method for manufacturing a laminated coil component according to the present disclosure (16), wherein the step of providing the layer containing the inorganic material is a step of laminating a solid plate-like member together with the ceramic green sheet in the step of producing the unfired laminate.

[0163] The present disclosure (21) is a method for manufacturing a laminated coil component according to the present disclosure (20), wherein the solid plate-like member contains the same ceramic material as the ceramic green sheet.

[0164] The present disclosure (22) is a method for manufacturing a laminated coil component according to the present disclosure (20), wherein the solid plate-like member contains the same metal element as the conductor paste that will become the coil conductor layer.

Example

[0165] Hereinafter, examples specifically disclosing the present invention are shown. It should be noted that the present invention is not limited only to these examples.

[0166] (Example 1 and Comparative Example 1) <Fabrication of laminated coil component> According to the method for manufacturing the laminated coil component described above, 20 laminated bodies each according to Example 1 provided with a plate-like member and 20 laminated bodies each according to Comparative Example 1 not provided with a plate-like member were produced respectively. The dimensions of all the laminated bodies were 3225 size (length × height × width = 3.2 mm × 2.5 mm × 2.5 mm). As shown in FIG. 2, the laminated body according to Example 1 had six-layer via sheets arranged on each of the first end face side and the second end face side, and two plate-like members were arranged only on the first end face side. Also, the number of laminated coil sheets was 72. Further, the circumferential shape of the coil was made such that the inner contour shape was a square with each side approximately 480 μm. The plate-like member was formed by printing a square region on the surface of the via sheet, in the region inside the circumferential shape of the coil, using the same Ag paste as the internal electrode. At this time, the Ag paste that becomes the plate-like member does not contact the conductor paste that becomes the via conductor, and the four sides of the square are arranged parallel to the inner contour shape of the circumferential shape of the coil at a position where its center of gravity overlaps with the center of gravity of the inner contour shape of the circumferential shape of the coil.

[0167] The cross-section polished from the side surface (LT surface) to the center of the W dimension of the laminated coil component according to Example 1 was observed with a digital microscope, and the length from the most protruding part of the first end face in the length direction L of the laminated body to the most recessed part of the part overlapping the inside of the coil circumferential shape was measured as the depth of the recess (the depth of the first recess), and it was 10.4 μm. The thickness of the plate-like member in the same cross-section was 22.0 μm per sheet, the interval between the two plate-like members was 28.0 μm, the distance from the first end face of the laminated body to the plate-like member in the length direction of the laminated body was 60.4 μm, and the distance from the outermost layer of the coil to the plate-like member in the length direction of the laminated body was 22.3 μm. Furthermore, it was confirmed that the dimension in the height direction of the plate-like member was 435 μm from the same cross-section. From this, the outer contour shape of the plate-like member was a square with one side being 435 μm, and its area was 189225 μm 2 and it was confirmed that it was so. Similarly, it was confirmed that the height of the inner contour shape of the coil's circumferential shape was 526 μm from the same cross-section. From this, the inner contour shape of the coil's circumferential shape is a square with one side being 526 μm, and its area (the cross-sectional area of the coil) is 276676 μm 2 was confirmed to be so.

[0168] The laminate according to Comparative Example 1 was made the same as the laminate according to Example 1, except that the plate-like member was not arranged. Regarding the laminated coil component according to Comparative Example 1, when the depth of the dent was measured in the same manner as in Example 1, it was 45 μm.

[0169] From the above results, it was confirmed that the coil marks of the laminate can be reduced by the plate-like member.

[0170] (Examples 2 to 6) The laminated coil component was manufactured in the same procedure as in Example 1, except that the size (the length of one side of the square) of the Ag paste printed on the via sheet was changed, and the length of each side of the outer contour shape of the plate-like member was changed to 115 μm, 285 μm, 520 μm, 605 μm, and 229 μm, respectively, and the depth (size) of the dent was measured. The results are shown in Table 1.

[0171]

Table 1

[0172] As shown in Table 1, it was confirmed that by changing the area of the plate-like member, the depth (size) of the coil marks can be controlled. From the above, it was found that the laminated coil component of the present invention can reduce the coil marks on the end face of the laminate and suppress the structural defects of the external electrodes.

[0173] FIG. 14 is a graph plotting the relationship between the ratio of the area of the plate-like member to the cross-sectional area of the coil and the depth of the dent for the laminated coil components according to Examples 1 to 6, with an approximate curve added. The approximate curve shown in FIG. 14 (R 2From (η = 0.9985), in order to make the depth of the recess (the size of the coil mark) 22.5 μm or less, it was confirmed that the area of the plate-like member should be 0.18 or more and 1.40 or less of the cross-sectional area of the coil. Even when a conductive paste serving as an external electrode is applied to the end face of the laminate by the dip method, if the depth of the coil mark is 22.5 μm or less, it is considered that poor formation of the external electrode is less likely to occur. Therefore, it can be said that the laminated coil components according to Examples 1 and 3 to 6 are particularly suitable for laminated coil components manufactured by the dip method.

Explanation of Signs

[0174] 1 Laminated coil component 10, 100, 101, 102, 103, 104, 105 Laminate 11, 11’ First end face 11a, 11a’ First recess 11a1, 11a1’ Deepest part of the first recess 11b, 11b’ First protrusion 11b1, 11b1’ Apex of the first protrusion 12, 12’ Second end face 12a, 21a’ Second recess 12a1, 12a1’ Deepest part of the second recess 12b, 12b’ Second protrusion 12b1, 12b1’ Apex of the second protrusion 13, 13’ First main surface 14, 14’ Second main surface 15, 15’ First side surface 16, 16’ Second side surface 21, 21’ First external electrode 22, 22’ Second external electrode 23’ Gap 24’ Crack 30 Coil 31a, 31b, 31c, 31d, 31e, 31f Insulating layer 32, 32a, 32b, 32c, 32d Coil conductor 33, 33a, 33b, 33c, 33d, 33e, 33f Via conductor 34, 34a, 34b, 34c, 34d circumferential part 35, 35a, 35b, 35c, 35d, 35e, 35f land 37a, 37b, 37c, 37d, 37e, 37f, 137e, 137f plate-like member 41 first lead-out conductor 42 second lead-out conductor 131a, 131b, 131c, 131d, 131e, 131f, 231e, 231f insulating layer (with plate-like member) A coil axis of the coil d1, d1’ depth of the first recess d2, d2’ depth of the second recess

Claims

1. A laminate in which a plurality of insulating layers are laminated and which has a coil inside, and a first external electrode and a second external electrode electrically connected to the coil, wherein the coil is formed by electrically connecting a plurality of coil conductors laminated together with the insulating layer, the laminate has a first end face and a second end face facing each other in the length direction, a first main face and a second main face facing each other in the height direction orthogonal to the length direction, and a first side face and a second side face facing each other in the width direction orthogonal to the length direction and the height direction, the coil axis of the coil is parallel to the first main face, the laminate further has a plate-like member laminated together with the insulating layer and having a dimension in a direction perpendicular to the coil axis larger than a dimension in a direction parallel to the coil axis, a laminated coil component, wherein an area of the plate-like member is smaller than an area of the first end face of the laminate.

2. The laminated coil component according to claim 1, wherein the area of the plate-like member is 1.63 or less when the cross-sectional area of the coil is taken as 1.

3. The laminated coil component according to claim 1, wherein the plate-like member is provided between the coil conductor closest to the first end face and the first end face in the length direction.

4. The plate-like member is provided at a position exposed from the first end face of the laminate, and the first external electrode covers at least a part of the plate-like member. The laminated coil component according to claim 1.

5. The laminated coil component according to claim 1, wherein the plate-like member is provided inside the coil.

6. The laminated coil component according to claim 1, wherein the plate-like member is made of an inorganic material.

7. The laminated coil component according to claim 1, wherein the plate-like member contains the same metal element as the coil.

8. The laminated coil component according to claim 1, wherein the plate-like member is made of metal and is electrically connected to the coil.

9. The laminated coil component according to claim 1, wherein the plate-like member contains the same ceramic material as the insulating layer.

10. The laminated coil component according to claim 1, wherein two or more plate-like members are provided.

11. At least one of the plate-like members is provided between the coil conductor closest to the first end face and the first end face in the length direction. At least one of the plate-like members is provided between the coil conductor closest to the second end face and the second end face in the length direction, and the laminated coil component according to claim 10.

12. When the laminate is bisected in the length direction and divided into a region on the first end face side and a region on the second end face side, at least one of the plate-like members is provided in both the region on the first end face side and the region on the second end face side, and the number of the plate-like members provided is different between the region on the first end face side and the region on the second end face side, and the laminated coil component according to claim 10.

13. The difference between the depth of the recess at the first end face of the laminate and the depth of the recess at the second end face of the laminate is 12 μm or less, and the laminated coil component according to claim 1.

14. The area of the plate-like member is in the range of 0.18 or more and 1.40 or less when the cross-sectional area of the coil is 1, and the laminated coil component according to claim 1.

15. When viewed through the laminate from the length direction, The outer shape of the plate-like member and the inner shape of the circumferential shape of the coil are similar, and the laminated coil component according to claim 1.

16. A step of preparing a ceramic green sheet containing a ceramic material; A printing step of printing a conductor paste to be a coil conductor layer and / or a via conductor on the ceramic green sheet; A step of laminating the ceramic green sheet on which the coil conductor layer is formed to produce an unfired laminate containing an unfired coil; A step of firing the unfired laminate to produce a laminate, and including, Furthermore, in the step of producing the unfired laminate or the printing step, a step of providing a layer containing an inorganic material having an area smaller than that of the ceramic green sheet is provided, and a method for manufacturing a laminated coil component, characterized in that.

17. The step of providing the layer containing the inorganic material is a step of printing a paste containing the inorganic material on a part of the surface of the ceramic green sheet, and the method for manufacturing a laminated coil component according to claim 16.

18. The paste to be printed contains the same ceramic material as the ceramic green sheet, and the method for manufacturing a laminated coil component according to claim 17.

19. The paste to be printed contains the same metal element as the conductor paste to be the coil conductor layer, and the method for manufacturing a laminated coil component according to claim 17.

20. The method for manufacturing a laminated coil component according to claim 16, wherein the step of providing the layer containing the inorganic material is a step of laminating a solid plate-like member together with the ceramic green sheet in the step of manufacturing the unfired laminate.

21. The method for manufacturing a laminated coil component according to claim 20, wherein the solid plate-like member contains the same ceramic material as the ceramic green sheet.

22. The method for manufacturing a laminated coil component according to claim 20, wherein the solid plate-like member contains the same metal element as the conductor paste that will become the coil conductor layer.

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