Laminated coil component

Abstract

The present invention provides a laminated coil component capable of alleviating residual stress generated between a coil conductor and an insulating layer around the coil conductor while maintaining the strength of a laminated body. The laminated coil component is provided with: a laminated body in which a plurality of insulating layers are laminated and which has a coil therein; and a first external electrode and a second external electrode which are electrically connected to the coil and form the coil by electrically connecting a plurality of coil conductors stacked together with the insulating layer, the coil conductor having three or more layers, the cross-sectional shape of the coil conductor being a flat shape when viewed in a cross-section in a direction perpendicular to the direction in which the coil conductor extends, and the cross-sectional shape of the coil conductor being a flat shape when viewed in a cross-section in a direction perpendicular to the direction in which the coil conductor extends. The coil conductor closest to the center of the laminated body in the lamination direction is defined as a first coil conductor, a gap is provided between one surface of at least one of the coil conductors other than the first coil conductor and the insulating layer, and no gap is provided between the outer peripheral end of the first coil conductor and the insulating layer.

Description

Technical Field

[0001] The present invention relates to a stacked coil component. Background Art

[0002] Patent Document 1 discloses a stacked inductor that is formed by firing a stacked body formed by stacking a magnetic body paste obtained by mixing a binder in magnetic powder and a conductive paste. The stacked inductor is characterized in that a void portion is provided between a conductor layer forming an internal coil and a magnetic body layer.

[0003] Patent Document 1: Japanese Patent Laid-Open No. 11-219821

[0004] In the stacked inductor described in Patent Document 1, as Figure 3 shown, a technique of providing a void portion around the entire circumference of the coil is disclosed.

[0005] By providing a void in this way to cut the adhesion at the interface between the coil conductor and the surrounding insulating layer, it is possible to reduce the residual stress caused by the difference in shrinkage rate during firing between the coil conductor material and the insulating layer material (generally, the shrinkage rate of the coil conductor material is larger than that of the insulating layer material). Therefore, it is possible to suppress a decrease in the magnetic permeability of the stacked body and a decrease in the Z characteristic (electrical characteristic) of the inductor due to the residual stress, and to improve the Z characteristic of the inductor.

[0006] However, in the case of forming a void around the entire circumference of the coil conductor as in the stacked inductor described in Patent Document 1, the proportion of voids in the stacked body (green body) becomes too large, and as a result, the strength of the stacked body itself decreases. In particular, the voids provided at the outer peripheral side end portion of the coil conductor are likely to concentrate external stress, and there is a risk of cracks occurring in the vicinity thereof. In addition, bending stress and external forces such as an installer nozzle are largely concentrated near the central portion of the stacked body, and there is a risk of cracks occurring in this portion. Summary of the Invention

[0007] The present invention has been made to solve the above problems, and an object thereof is to provide a stacked coil component that can relieve the residual stress generated between a coil conductor and its surrounding insulating layer while maintaining the strength of the stacked body.

[0008] In a first mode, the stacked coil component of the present invention includes: a stacked body formed by stacking 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 being formed by electrically connecting a plurality of coil conductors stacked together with the insulating layer, the coil conductors being three or more layers, and when observing a cross-section in a direction perpendicular to the extending direction of the coil conductors, the cross-sectional shape of the coil conductors is a flat shape. The coil conductor closest to the center of the stacked body in the stacking direction is defined as the first coil conductor, and a gap is provided between at least one of the coil conductors other than the first coil conductor and the insulating layer, and no gap is provided between the outer peripheral side end of the first coil conductor and the insulating layer.

[0009] In a second mode, the stacked coil component of the present invention includes: a stacked body formed by stacking 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 being formed by electrically connecting a plurality of coil conductors stacked together with the insulating layer, and a gap is provided between at least one of the coil conductors and the insulating layer, biased toward the inner peripheral side of the coil conductor.

[0010] According to the present invention, it is possible to provide a stacked coil component that can relieve the residual stress generated between the coil conductor and the surrounding insulating layer while maintaining the strength of the stacked body. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a perspective view schematically showing an example of the stacked coil component of Embodiment 1.

[0012] Figure 2 It schematically shows Figure 1 An exploded perspective view of an example of the stacked body constituting the stacked coil component shown.

[0013] Figure 3 It is a side view schematically showing an example of the internal structure of the stacked body constituting the stacked coil component shown and schematically showing it. Figure 1 A side view schematically showing an example of the internal structure of the stacked body constituting the stacked coil component shown and schematically showing it.

[0014] Figure 4 It schematically shows Figure 1 A cross-sectional view of an example of the cross-section along line A1 - A1 of the stacked coil component shown.

[0015] Figure 5 It schematically shows Figure 1 A cross-sectional view of another example (Modification 1) of the cross-section along line A1 - A1 of the stacked coil component shown.

[0016] Figure 6Schematically represents Figure 1 A cross-sectional view of another example (Modification 2) of the laminated coil component shown along line A1 - A1.

[0017] Figure 7 Schematically represents the constitution of Figure 1 An exploded perspective view of another example (Modification 3) of the laminate of the laminated coil component shown.

[0018] Figure 8 Is a perspective view of the internal structure of another example (Modification 3) of the laminate of the laminated coil component shown and schematically shows a side view. Figure 1 An example of the internal structure of another example (Modification 3) of the laminate of the laminated coil component shown and schematically shows a side view.

[0019] Figure 9 Schematically represents Figure 1 A cross-sectional view of another example (Modification 3) of the laminated coil component shown along line A1 - A1.

[0020] Figure 10 Is a perspective view of the internal structure of another example (Modification 3) of the laminate of the laminated coil component shown and schematically shows a view from the second end face side of the laminate. Figure 1 An example of the internal structure of another example (Modification 3) of the laminate of the laminated coil component shown and schematically shows a view from the second end face side of the laminate.

[0021] Figure 11 Is a schematic diagram showing the models of Examples 1 and 2 and Comparative Examples 1 and 2 used in stress simulation.

[0022] Figure 12 Is a diagram showing the results of stress analysis of the models of Examples 1 and 2 and Comparative Examples 1 and 2.

[0023] Figure 13 Is a graph showing the stress values of Examples 1 and 2 and Comparative Examples 1 and 2.

[0024] Figure 14 Is a schematic diagram showing the models of Examples 3 and 4 and Comparative Examples 3 and 4 used in stress simulation.

[0025] Figure 15 Is a diagram showing the results of stress analysis of the models of Examples 3 and 4 and Comparative Examples 3 and 4.

[0026] Figure 16 Is a graph showing the stress values of Examples 3 and 4 and Comparative Examples 3 and 4.

[0027] Figure 17 Is a schematic diagram showing the test method in the verification of the side clearance amount.

[0028] Figure 18 Is a cross-sectional view schematically showing an example of the laminated coil component of Embodiment 2.

[0029] Figure 19 It is a cross-sectional view schematically showing another example of the stacked coil component of Embodiment 2, showing the coil conductor and its vicinity.

[0030] Figure 20 It is a schematic view showing the models of Example 5 and Comparative Examples 5 and 6 used for stress simulation.

[0031] Figure 21 It is a diagram showing the results of the stress analysis of the models of Example 5 and Comparative Examples 5 and 6.

[0032] Figure 22 It is a graph showing the stress values of Example 5 and Comparative Examples 5 and 6.

[0033] Explanation of reference numerals: 1, 81... Stacked coil component; 10... Stacked body; 11... First end face; 12... Second end face; 13... First main face; 14... Second main face; 15... First side face; 16... Second side face; 21... First external electrode; 22... Second external electrode; 30... Coil; 31, 31a, 31b, 31c, 31d, 31e, 31f... Insulating layer; 32, 32a, 32b, 32c, 32d, 132... Coil conductor; 33, 33a, 33b, 33c, 33d, 33e, 33f... Via conductor; 34, 34a, 34b, 34c, 34d... Surrounding portion; 35, 35a, 35b, 35c, 35d, 35e, 35f... Pad; 36... First face; 37... Second face; 38, 61, 71, 138... Inner peripheral side end portion; 38P... Inner peripheral side front end; 39, 62, 72, 139... Outer peripheral side end portion; 39P... Outer peripheral side front end; 41... First lead conductor; 42... Second lead conductor; 51, 52, 150... Gap; 60, 160... First coil conductor; 70... Second coil conductor; 82... Substrate; 83a, 83b... Support portion; A... Coil axis of the coil; B... Center line; G1... Spacing in the height direction between the coil and the first main face; G2... Spacing in the height direction between the coil and the second main face. Detailed implementation manners

[0034] Hereinafter, the stacked coil component of the present invention will be described. In addition, the present invention is not limited to the following structure, and can also be appropriately changed without departing from the gist of the present invention. In addition, a structure formed by combining a plurality of the following described preferred structures is also the present invention.

[0035] The accompanying drawings shown below are schematic diagrams, and sometimes their dimensions, aspect ratio scales, etc. are different from those of the actual product. In the drawings, the same reference numerals are used for the same or corresponding parts. In addition, in each drawing, the same reference numerals are assigned to the same elements and repeated descriptions are omitted.

[0036] In this specification, terms indicating the relationality between elements (e.g., "parallel", "orthogonal", etc.) and terms indicating the shape of elements do not mean strict forms in the literal sense, but also mean substantially equivalent ranges, for example, ranges including differences of about several percent.

[0037] Each of the embodiments shown below is an example, and of course, partial replacement or combination of the structures shown in different embodiments can be performed. After the second embodiment, descriptions of matters common to the first embodiment are omitted, and only different points are described. In particular, the same effects brought about by the same structures are not sequentially mentioned in each embodiment.

[0038] (Embodiment 1)

[0039] Figure 1 It is a perspective view schematically showing an example of the stacked coil component of Embodiment 1.

[0040] Figure 1 The stacked coil component 1 shown includes a laminate (green body) 10, a first external electrode 21 provided on the outer surface of the laminate 10, and a second external electrode 22. The laminate 10 has a rectangular parallelepiped shape with six faces. The structure of the laminate 10 will be described later, but it is formed by laminating a plurality of insulating layers and a plurality of coil conductors in the stacking direction, and a coil is provided inside. The first external electrode 21 and the second external electrode 22 are electrically connected to the coil respectively.

[0041] In the stacked coil component and the laminate in this specification, the length direction, the height direction, and the width direction are set as Figure 1 the L direction, the T direction, and the W direction in

[0042] Here, the length direction L is the direction parallel to the stacking direction.

[0043] As Figure 1 shown, 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.

[0044] Although in Figure 1Although not shown, it is preferable that the laminated body 10 has rounded corners and ridge lines. A corner is a part where three faces of the laminated body intersect, and a ridge line is a part where two faces of the laminated body intersect.

[0045] For example, as Figure 1 shown, the first external electrode 21 covers the entire first end face 11 of the laminated body 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.

[0046] For example, as Figure 1 shown, the second external electrode 22 covers the entire second end face 12 of the laminated body 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.

[0047] When the laminated coil component 1 configured with the first external electrode 21 and the second external electrode 22 as described above is mounted 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 laminated body 10 becomes the mounting face.

[0048] However, it is sufficient that the first external electrode 21 extends from at least a part of the first end face 11 of the laminated body 10 to the mounting face of the laminated body 10.

[0049] Similarly, it is sufficient that the second external electrode 22 extends from at least a part of the second end face 12 of the laminated body 10 to the mounting face of the laminated body 10.

[0050] The first external electrode 21 and the second external electrode 22 may each be a single-layer structure or a multi-layer structure.

[0051] When the first external electrode 21 and the second external electrode 22 are each a single-layer structure, examples of the constituent material of each external electrode include Ag, Au, Cu, Pd, Ni, Al, an alloy containing at least one of these metals, and the like.

[0052] When the first external electrode 21 and the second external electrode 22 are each a multi-layer structure, each external electrode may also have, for example, a base electrode layer containing Ag, a Ni covering film, and a Sn covering film in this order from the surface side of the laminated body 10.

[0053] The size of the laminated coil component of the present invention is not particularly limited, but is preferably a 1608 size, a 0603 size, a 0402 size, or a 1005 size.

[0054] Figure 2 It schematically shows the constitution Figure 1Exploded perspective view of an example of a stacked body of stacked coil components shown.

[0055] As Figure 2 shown, the stacked body 10 is formed by stacking a plurality of insulating layers 31a, 31b, 31c, 31d, 31e, and 31f from the first end face 11 side of the stacked body 10 toward the second end face 12 side in the stacking direction (here, the length direction L). Hereinafter, the insulating layers 31a, 31b, 31c, 31d, 31e, and 31f will also be collectively referred to as the insulating layer 31.

[0056] In addition, in this specification, the direction in which a plurality of insulating layers constituting the stacked body are stacked is referred to as the stacking direction.

[0057] In Figure 2 , the insulating layer 31e is disposed on the lower side in the stacking direction (the first end face 11 side of the stacked body 10), and the insulating layer 31f is disposed on the upper side in the stacking direction (the second end face 12 side of the stacked body 10).

[0058] As the constituent material of each insulating layer 31, for example, a magnetic material such as a ferrite material is cited.

[0059] Coil conductors 32a, 32b, 32c, and 32d and via conductors 33a, 33b, 33c, and 33d are provided in the insulating layers 31a, 31b, 31c, and 31d, respectively. A via conductor 33e and a pad 35e are provided in the insulating layer 31e. A via conductor 33f and a pad 35f are provided in the insulating layer 31f. The insulating layer 31e may be one layer or two or more layers. Similarly, the insulating layer 31f may be one layer or two or more layers. Hereinafter, the coil conductors 32a, 32b, 32c, and 32d will also be collectively referred to as the coil conductor 32.

[0060] The coil conductors 32a, 32b, 32c, and 32d are respectively provided on the main surfaces of the insulating layers 31a, 31b, 31c, and 31d and are stacked together with the insulating layers 31a, 31b, 31c, 31d, 31e, and 31f. In Figure 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 repeatedly stacked as one unit (3 turn amount).

[0061] In addition, the coil conductors 32a, 32b, 32c, and 32d each include an annular surrounding portion 34a, 34b, 34c, and 34d with a gap locally vacated by lacking one place, and pads 35a, 35b, 35c, and 35d. Pads 35a, 35b, 35c, and 35d are respectively provided at both end portions of each of the surrounding portions 34a, 34b, 34c, and 34d. Hereinafter, the surrounding portions 34a, 34b, 34c, and 34d will also be collectively referred to as the surrounding portion 34.

[0062] The via conductors 33a, 33b, 33c, 33d, 33e, and 33f are respectively provided to penetrate the insulating layers 31a, 31b, 31c, 31d, 31e, and 31f in the stacking direction. Hereinafter, the via conductors 33a, 33b, 33c, 33d, 33e, and 33f will also be collectively referred to as the via conductor 33.

[0063] Pads 35e and 35f are respectively provided directly above the via conductors 33e and 33f. It is preferable that the pads 35a, 35b, 35c, 35d, 35e, and 35f are slightly wider than the line widths of the surrounding portions 34a, 34b, 34c, and 34d. Hereinafter, the pads 35a, 35b, 35c, 35d, 35e, and 35f will also be collectively referred to as the pad 35. The pad 35 is larger than the adjacent via conductor 33, and when observed in the stacking direction (length direction L), the via conductor 33 adjacent to the pad 35 is accommodated within the area of the pad 35.

[0064] As the constituent materials of each of the coil conductors 32 including the surrounding portion 34 and the pad 35 and each of the via conductors 33, for example, Ag, Au, Cu, Pd, Ni, Al, alloys containing at least one of these metals, etc. are listed.

[0065] The plurality of insulating layers 31a, 31b, 31c, 31d, 31e, and 31f configured as described above are stacked in the stacking direction. Thereby, the stacked body 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 stacked body 10.

[0066] In addition, the via conductor 33e and the pad 35e become the first lead conductor within the stacked body 10 and are exposed at the first end face 11 of the stacked body 10. That is, the first lead conductor includes the via conductor 33e and the pad 35e. As will be described later, the first lead conductor connects the first external electrode 21 and the coil conductor 32a opposed thereto within the stacked body 10.

[0067] The via hole conductor 33f and the pad 35f become the second lead conductor within the laminate 10 and are exposed at the second end face 12 of the laminate 10. That is, the second lead conductor includes the via hole conductor 33f and the pad 35f. As will be described later, the second lead conductor connects the second external electrode 22 and the coil conductor 32d opposed thereto within the laminate 10.

[0068] When viewed in the stacking direction (length direction L), it is preferable that the coil conductors 32 overlap each other. In addition, when viewed in the stacking direction, the coil may be Figure 2 a shape composed of straight portions (e.g., a polygonal shape such as a rectangle) as shown, or a shape composed of curved portions (e.g., a circle), or a shape composed of straight portions and curved portions.

[0069] Figure 3 is a perspective view Figure 1 showing an example of the internal structure of the laminate of the stacked coil component shown and schematically showing a side view.

[0070] As Figure 3 shown, in the stacked coil component 1, a plurality of insulating layers 31 are stacked in the length direction L, so the length direction L is the stacking direction. In addition, the stacking 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, and the second side surface 16 as the mounting surface, for example, the first main surface 13. That is, the stacked coil component 1 is a horizontally wound stacked inductor in which the coil 30 is provided such that the coil axis A is parallel to the mounting surface.

[0071] In addition, as Figure 3 shown, actually, no boundary can be confirmed between adjacent insulating layers 31.

[0072] The first lead conductor 41 extends in the stacking direction within the laminate 10 and linearly connects the first external electrode 21 provided on the first end face 11 and the coil conductor 32a opposed thereto. Similarly, the second lead conductor 42 extends in the stacking direction within the laminate 10 and linearly connects the second external electrode 22 provided on the second end face 12 and the coil conductor 32d opposed thereto.

[0073] In addition, when viewed in the stacking direction (length direction L), it is preferable that the via hole conductors constituting the lead conductor overlap each other, but the via hole conductors constituting the lead conductor may not be strictly linearly arranged with respect to each other.

[0074] In addition, in Figure 2 and Figure 3In this case, an example is shown where the number of layers of the coil conductor 32 that forms three turns of the coil 30 is four, that is, the repeating shape is a 3 / 4 turn shape. However, the number of layers of the coil conductor 32 that forms one turn of the coil 30 is not particularly limited.

[0075] For example, the number of layers of the coil conductor 32 that forms one turn of the coil 30 can also be two, that is, the repeating shape is a 1 / 2 turn shape.

[0076] In addition, the number of layers of the coil conductor 32, that is, the total number of layers of all the coil conductors 32 included in the laminate 10, is not particularly limited as long as it is three or more, and is preferably 10 or more and 60 or less. As Figures 2 to 4 shown, the number of layers of the coil conductor 32 can also be three or more and an odd number of layers.

[0077] Figure 4 is a cross-sectional view schematically showing Figure 1 an example of the cross-section along the line A1 - A1 of the laminated coil component shown. In addition, Figure 4 represents the cross-section of the surrounding portion 34 in the coil conductor 32.

[0078] As Figure 4 shown, when observing the cross-section in a direction perpendicular to the extending direction of the coil conductor 32, the cross-sectional shape of the coil conductor 32 is a flat shape (long strip shape), and its long side direction is orthogonal to the lamination direction (length direction L). In Figure 4 the example shown, 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. For example, it can also be a rectangle with the same length of a pair of opposite sides in the lamination direction, a trapezoid with different lengths of a pair of opposite sides in the lamination direction, etc.

[0079] In addition, as Figure 4 shown, the coil conductors 32 each have a first surface 36 facing the first direction parallel to the coil axis A and a second surface 37 facing the side opposite to the first direction. Both the first surface 36 and the second surface 37 extend in a direction orthogonal to the lamination direction.

[0080] Here, the coil conductor 32 closest to the center of the laminate 10 in the lamination direction (length direction L) (refer to Figure 3 and Figure 4 for the center line B) is set as the first coil conductor 60 (refer to Figure 4 ).

[0081] Moreover, a gap 51 is provided between one side surface of at least one of the coil conductors 32 other than the first coil conductor 60 and the insulating layer 31, and no gap is provided between the outer peripheral side end portion 62 of the first coil conductor 60 and the insulating layer 31. In this way, for the coil conductors 32 present in the central portion of the laminate 10, no gap is provided at least adjacent to the outer peripheral side end portion 62, and for the other coil conductors 32, a gap is provided adjacent to one side surface, so that the strength of the laminate 10 can be maintained and the residual stress generated between the coil conductor 32 and the surrounding insulating layer can be alleviated. Hereinafter, the case where a gap 51 is provided between one side surface of the coil conductor 32 and the insulating layer 31 may be simply described as "a gap is provided on one side surface of the coil conductor 32".

[0082] In addition, in this specification, a "gap" refers to a space where the coil and the insulating layer do not contact (i.e., the space between the coil and the insulating layer), and its thickness is 1.5 μm or more. Therefore, when the thickness of the space where the coil and the insulating layer do not contact is less than 1.5 μm, this space is not treated as a gap. For example, even if bubbles or the like with a thickness less than 1.5 μm exist between the coil and the insulating layer, they are not treated as gaps.

[0083] In the case where a gap is formed around the entire circumference of all coil conductors or a gap is formed only on one side surface of all coil conductors as in the case of the laminated inductor described in Patent Document 1, a gap also exists near the central portion of the laminate where external stress is likely to concentrate during the installation of the laminated coil component, and external stress is likely to concentrate in this gap portion. In addition, for example, when a bending stress is applied as an external stress, the bending stress is likely to be applied to the central portion of the laminate in the stacking direction, particularly to the outer peripheral side end portion of the coil conductor at the central portion of the laminate in the stacking direction. This bending stress is particularly likely to be applied during the manufacturing and transportation of the laminated coil component, and cracks may occur starting from the gap at the outer peripheral side end portion of the coil conductor at the central portion of the laminate in the stacking direction due to the bending stress. In contrast, in the present embodiment, no gap is provided at the outer peripheral side end portion 62 of the first coil conductor 60 closest to the center of the laminate 10 in the stacking direction, so that such external stress can be alleviated, and as a result, the strength of the laminate 10 can be maintained.

[0084] In addition, although it is a problem peculiar to the horizontally wound laminated inductor, the strength against the stress applied to the laminate by the installer nozzle during installation can also be improved. Specifically, the installer nozzle presses the central portion of the outer surface of the laminate facing the installation surface in the stacking direction, so that stress is applied to the laminate starting from there. According to the laminated coil component 1 which is a horizontally wound laminated inductor, the strength against cracks caused by this stress can also be improved.

[0085] On the other hand, external stress is not likely to concentrate on parts of the laminate other than the central part in the lamination direction. Therefore, a gap 51 is provided for the coil conductor 32 other than the first coil conductor 60, that is, the coil conductor 32 far from the center of the laminate 10 in the lamination direction, so as to relieve the residual stress caused by the difference in shrinkage rates during firing between the coil conductor material and the insulating layer material. However, by providing the gap 51 only on one side of the coil conductor 32, the proportion of the gap 51 in the laminate 10 is prevented from becoming too large and the strength of the laminate 10 itself is reduced.

[0086] Based on the above, it is possible to balance the strength assurance of the laminate 10 and the relief of residual stress.

[0087] In this specification, the inner peripheral side and the outer peripheral side of the coil conductor respectively refer to the coil axis side of the coil and the opposite side thereof (the outside of the coil).

[0088] In addition, the one side of the coil conductor 32 provided with the gap 51 may be either the first surface 36 or the second surface 37 of the coil conductor 32. Additionally, as Figure 4 shown, when the gap 51 is provided on one side of multiple coil conductors 32, the surfaces provided with the gap 51 may be either the first surface 36 or the second surface 37 respectively, or the coil conductors 32 with the gap 51 provided on the first surface 36 and the coil conductors 32 with the gap 51 provided on the second surface 37 may be mixed, but if they are all the same as one of the first surface 36 and the second surface 37, it is easy to manufacture.

[0089] In addition, no gap is provided between the surface opposite to the one side of the coil conductor 32 provided with the gap 51 and the insulating layer 31.

[0090] In addition, when two coil conductors 32 are equally spaced from the center (center line B) of the laminate 10 in the lamination direction, that is, when the center line B exists at the center between two adjacent coil conductors 32, either one of these two coil conductors 32 serves as the first coil conductor 60. Therefore, in this case, a gap 51 is provided between the one side of at least one of the coil conductors 32 other than these two first coil conductors 60 and the insulating layer 31, and no gap is provided between the outer peripheral end portions 62 of these two first coil conductors 60 and the insulating layer 31.

[0091] As Figure 4 shown, the gap 51 may also be provided between the one side of all the coil conductors 32 other than the first coil conductor 60 and the insulating layer 31. In this case, the residual stress can be further relieved.

[0092] In addition, as Figure 4As shown, it is also possible not to provide a gap between the first coil conductor 60 and the insulating layer 31. That is, there may be no gap around the entire circumference of the first coil conductor 60. In this case, the strength of the laminate 10 can be further improved.

[0093] Figure 5 schematically shows Figure 1 A cross-sectional view of another example (Modification 1) of the laminated coil component shown along line segment A1 - A1.

[0094] As Figure 5 shown, it is also possible not to provide a gap between each of the two coil conductors 32 adjacent to the first coil conductor 60 in the stacking direction of the laminate 10 and the insulating layer 31. That is, it is also possible not to provide a gap for a total of three coil conductors 32 located at the central portion in the stacking direction of the laminate 10. In this case, the strength of the laminate 10 can be further improved.

[0095] Figure 6 schematically shows Figure 1 A cross-sectional view of yet another example (Modification 2) of the laminated coil component shown along line segment A1 - A1.

[0096] As Figure 6 shown, it is also possible to provide a gap 51 between the inner peripheral side end portion 61 of the first coil conductor 60 and the insulating layer 31. Since external stress is particularly likely to concentrate on the outer peripheral side end portion of the coil conductor, even in this case, it is possible to balance the strength assurance of the laminate 10 and the relaxation of residual stress. In addition, since a gap 51 is also provided in the first coil conductor 60, the residual stress can be further relaxed. Furthermore, it is also possible to provide a gap between the central portion of the first coil conductor 60 and the insulating layer 31, or it is possible not to provide a gap.

[0097] Figure 7 schematically shows the components of Figure 1 An exploded perspective view of another example (Modification 3) of the laminate constituting the laminated coil component shown. Figure 8 is a perspective view of the components of Figure 1 Another example (Modification 3) of the laminate constituting the laminated coil component shown, and a side view schematically showing an example of the internal structure. Figure 9 schematically shows Figure 1 A cross-sectional view of another example (Modification 3) of the laminated coil component shown along line segment A1 - A1.

[0098] As Figures 7 to 9 shown, the number of stacked coil conductors 32 can also be four or more and an even number. Here, if the next one after the first coil conductor 60 is away from the center of the laminate 10 in the stacking direction (refer to Figure 8and Figure 9 a coil conductor 32 close to the center line B) in Figure 9 is set as a second coil conductor 70 (see Figure 9 ), a gap 51 may be provided between one side of at least one coil conductor 32 among the coil conductors 32 other than the first coil conductor 60 and the second coil conductor 70 and the insulating layer 31, and no gap is provided between the outer peripheral side end portion 62 of the first coil conductor 60 and the insulating layer 31 and between the outer peripheral side end portion 72 of the second coil conductor 70 and the insulating layer 31. Even in this case, the strength of the laminate 10 can be maintained, and the residual stress generated between the coil conductor 32 and the surrounding insulating layer can be alleviated.

[0099] As Figure 9 shown, a gap 51 may be provided between one side of all the coil conductors 32 other than the first coil conductor 60 and the second coil conductor 70 and the insulating layer 31. In this case, the residual stress can be further alleviated.

[0100] In addition, as Figure 9 shown, no gap may be provided between the first coil conductor 60 and the insulating layer 31 and between the second coil conductor 70 and the insulating layer 31. That is, no gap may exist in the entire circumference of the first coil conductor 60 and the entire circumference of the second coil conductor 70. In this case, the strength of the laminate 10 can be further improved.

[0101] In addition, although not shown, a gap may be provided between the inner peripheral side end portion 61 of the first coil conductor 60 and the insulating layer 31 and / or between the inner peripheral side end portion 71 of the second coil conductor 70 and the insulating layer 31 respectively (see Figure 6 ). In addition, a gap may be provided between the central portion of the first coil conductor 60 and the insulating layer 31, or a gap may not be provided. Similarly, a gap may be provided between the central portion of the second coil conductor 70 and the insulating layer 31, or a gap may not be provided.

[0102] In addition, no gap may be provided between each of two coil conductors 32 that are respectively on both sides of the first coil conductor 60 and the second coil conductor 70 in the stacking direction of the laminate 10. That is, no gap may be provided for a total of four coil conductors 32 located at the central portion in the stacking direction of the laminate 10. In this case, the strength of the laminate 10 can be further improved.

[0103] Here, the generation of cracks starting from the gap in the blank inside the laminated coil component 1 mounted on the substrate will be described.

[0104] Figure 10 is a perspective view showing the structure Figure 1The figure schematically showing an example of the internal structure of the laminate of the stacked coil components shown is a view observed from the second end face side of the laminate.

[0105] As Figure 10 shown, the clearance in the height direction between the coil 30 and the first main surface 13 is defined as the side clearance G1, and the clearance in the height direction between the coil 30 and the second main surface 14 is defined as the side clearance G2. Here, the first main surface 13 is the mounting surface.

[0106] When the substrate on which the stacked coil component is mounted is flexed, stress is applied inside the green body of the stacked coil component, particularly in the region near the end of the external electrode extending along the mounting surface. If the side clearance G1 becomes smaller, the distance between the first main surface 13 as the mounting surface and the coil conductor 32 becomes closer, and the distance to the void 51 provided on the coil conductor 32 also becomes closer. Moreover, if the side clearance G1 becomes too small, the void 51 approaches the above-mentioned region where stress is particularly applied, and cracks may occur inside the green body starting from the void 51.

[0107] Therefore, from the viewpoint of suppressing the generation of cracks accompanying the flexure of the substrate, the side clearance G1 is preferably ensured to a certain extent. Specifically, it is preferably 43 μm or more, more preferably 44 μm or more, and further preferably 46 μm or more. By setting the lower limit of the side clearance G1 in this way, cracks accompanying the flexure of the substrate can be prevented. In addition, the upper limit of the side clearance G1 is not particularly limited and may be 150 μm or less. Further, the side clearance G2 is not particularly limited and, like the side clearance G1, may be 43 μm or more and 150 μm or less.

[0108] If the size of the stacked coil component becomes smaller, the lower limit of the required side clearance G1 also becomes smaller. Therefore, in the stacked coil component 1 in which the side clearance G1 satisfies the above conditions, the generation of cracks accompanying the flexure of the substrate can be more effectively prevented. From this viewpoint, the size of the stacked coil component 1 is preferably 1608 size or less. For example, it is more preferably 1608 size, 1005 size, 0603 size, or 0402 size.

[0109] Hereinafter, the results of simulating the stress when an external stress is applied to the laminate 10 of the stacked coil component 1 of Embodiment 1 will be described.

[0110] Figure 11 It is a schematic diagram showing the models of Examples 1 and 2 and Comparative Examples 1 and 2 used in the stress simulation.

[0111] As Figure 11As shown, any model is configured with five layers of coil conductors 132. In the model of Example 1, no gap is provided in the first coil conductor 160 closest to the center of the laminate in the stacking direction, and gaps 150 are provided on one side of all coil conductors 132 except the first coil conductor 160. In the model of Example 2, no gaps are provided in the first coil conductor 160 closest to the center of the laminate in the stacking direction and the coil conductors 132 on its left and right sides, and gaps 150 are provided only on one side of the two outermost coil conductors 132. In the model of Comparative Example 1, gaps 150 are provided on the entire surface (entire circumference) of all coil conductors 132. In the model of Comparative Example 2, gaps 150 are provided only on one side of all coil conductors 132. In any model, the size of the laminate is assumed to be 1005 size, the size in the width direction W and the size in the height direction T are both 0.5 mm, the side gaps G1 and G2 are both 70 μm. The maximum thickness of the coil conductor is 20 μm, the line width of the coil conductor is 120 μm, and the thickness of the gap is 4 μm and constant. For each model, at Figure 11 the position (center of the upper surface) indicated by the vertex of the triangle in Figure 12 , Figure 13 and the following Table 1 shows the results.

[0112] Figure 12 is a diagram showing the results of stress analysis of the models of Example 1, 2 and Comparative Examples 1, 2. Figure 13 is a graph showing the stress values of Example 1, 2 and Comparative Examples 1, 2. Similarly, the following Table 1 shows the stress values of Example 1, 2 and Comparative Examples 1, 2. In addition, in Figure 13 and Table 1, the maximum stress value generated by each model is expressed as a relative value with respect to the maximum stress generated by the model of Comparative Example 1.

[0113] [Table 1]

[0114] Comparative Example 1 Comparative Example 2 Example 1 Example 2 Full-surface voids Single-sided voids One layer without voids Three layers without voids 100％ 81％ 12％ 8％

[0115] As a result, it can be seen that bending stress is easily applied to the outer peripheral side end of the coil conductor (refer to Figure 12 of Comparative Examples 1 and 2). In addition, in order to avoid stress from the central part in the stacking direction of the laminate, it is effective not to provide gaps in the coil conductors existing in the central part in the stacking direction of the laminate. As a result, it can be seen that stress can be significantly alleviated.

[0116] Figure 14 is a schematic diagram showing the models of Example 3, 4 and Comparative Examples 3, 4 used in the stress simulation.

[0117] As Figure 14As shown, here, any one of the models is configured with six layers of coil conductors 132, and two layers of coil conductors are arranged at equal intervals relative to the center of the stacked body in the stacking direction. In the model of Embodiment 3, no gap is provided in the two first coil conductors 160 closest to the center of the stacked body in the stacking direction, and a gap 150 is provided on one side of all the coil conductors 132 except the two first coil conductors 160. In the model of Embodiment 4, no gap is provided in the two first coil conductors 160 closest to the center of the stacked body in the stacking direction and the two coil conductors 132 on the left and right sides thereof, and a gap 150 is provided only on one side of the two outermost coil conductors 132. In the model of Comparative Example 3, a gap 150 is provided on the entire surface (entire circumference) of all the coil conductors 132. In the model of Comparative Example 4, a gap 150 is provided only on one side of all the coil conductors 132. Other conditions are the same as those of the model shown in Figure 11 The same applies to the models shown. For each model, at the position (center of the upper surface) indicated by the vertex of the triangle in Figure 14 the same bending stress is applied. Figure 15 , Figure 16 And the following Table 2 shows the results.

[0118] Figure 15 is a diagram showing the results of stress analysis of the models of Embodiment 3, 4 and Comparative Examples 3, 4. Figure 16 is a graph showing the stress values of Embodiment 3, 4 and Comparative Examples 3, 4. Similarly, the following Table 2 shows the stress values of Embodiment 3, 4 and Comparative Examples 3, 4. In addition, in Figure 16 and Table 2, the maximum stress value generated by each model is expressed as a relative value with respect to the maximum stress generated by the model of Comparative Example 3.

[0119] [Table 2]

[0120] Comparative Example 3 Comparative Example 4 Example 3 Example 4 Full-surface voids Single-sided voids Two layers without voids Four layers without voids 100％ 81％ 28％ 5％

[0121] As a result, the same results as those of Embodiment 1, 2 and Comparative Examples 1, 2 are obtained. That is, it is known that by not providing a gap in the coil conductor at the center in the stacking direction of the stacked body, the stress can be significantly alleviated.

[0122] Hereinafter, regarding the stacked coil component of the present embodiment, the results after verifying the side gap amount that does not cause cracks inside the green body will be described.

[0123] As specimens, 15 specimens were fabricated in which the amounts of the side clearances G1 and G2 of the laminated coil component, having a clearance only between the first surface and the insulating layer in the surrounding portions of all the coil conductors, were different. The manufacturing method of the laminated coil component of the present embodiment will be described later. The difference between this specimen and the laminated coil component of the present embodiment is that a clearance is also provided on the entire single surface of the surrounding portion of the first coil conductor. However, in this verification, only the structure near the external electrode of the green body is relevant, and even if a clearance is provided in the first coil conductor at the center of the green body, it does not affect the test results. All the laminated coil components were of the 1608 size. The dimensions of the 15 specimens were measured and the average values were obtained. Thus, the dimensions of the laminated coil component in the length direction L, width direction W, and height direction T, including the external electrodes, were 1.530 mm, 0.822 mm, and 0.822 mm, respectively, and the dimensions of the laminate in the length direction L, width direction W, and height direction T, excluding the external electrodes, were 1.372 mm, 0.783 mm, and 0.783 mm, respectively.

[0124] Figure 17 It is a schematic diagram showing the test method in the verification of the side clearance amount.

[0125] As Figure 17 shown, first, the laminated coil component 81 as a specimen was mounted on the substrate 82 with the first main surface as the mounting surface, and the substrate 82 was supported by the support portions 83a and 83b located at positions 45 mm from the center of the laminated coil component 81 in the length direction, respectively, so that the laminated coil component 81 was on the lower side. Then, stress was applied to the central portion of the laminated coil component 81 from the back surface of the substrate 82 on which the laminated coil component 81 was not mounted until the bending amount of the substrate 82 became 3 mm, and it was confirmed whether cracks were generated inside the green body of the laminated coil component 81. In addition, if the bending amount is 2 mm, it is also sufficient in practice, but here, the test was further generously carried out with 3 mm. The results are shown in Table 3 below.

[0126] [Table 3]

[0127] Specimen number G1 (μm) G2 (μm) Presence or absence of cracks 1 65.40 53.63 None 2 66.73 54.20 None 3 67.06 41.26 None 4 53.12 48.46 None 5 37.34 74.30 Yes 6 49.89 52.37 None 7 46.70 72.55 None 8 55.60 54.02 None 9 57.83 52.14 None 10 57.86 52.93 None 11 41.45 68.99 Yes 12 63.23 46.05 None 13 49.51 51.07 None 14 49.53 72.96 None 15 52.41 56.31 None

[0128] From this result, it can be seen that the side clearance G1 is preferably 43 μm or more, more preferably 44 μm or more, and further preferably 46 μm or more.

[0129] (Embodiment 2)

[0130] Figure 18 It is a cross-sectional view schematically showing an example of the laminated coil component of Embodiment 2. Figure 18 It is Figure 4 corresponding to the cross-sectional view, and the drawing shows Figure 1The cross-section corresponding to the cross-section along line segment A1 - A1 of the stacked coil component shown.

[0131] In the stacked coil component 1A of Embodiment 2, as Figure 18 shown, between at least one coil conductor 32 and the insulating layer 31, a gap 52 is provided on the inner peripheral side of the coil conductor 32, being biased towards the inner peripheral side. In this way, no gap is provided on the outer peripheral side of the coil conductor 32 where external stress is likely to concentrate, and the gap 52 is concentrated on the inner peripheral side of the coil conductor 32, thereby being able to relieve external stress and maintain the strength of the laminate 10. In addition, compared with the case where gaps are formed over the entire circumference of all coil conductors as in the laminated inductor described in Patent Document 1, the strength of the laminate 10 can be improved.

[0132] On the other hand, since external stress is not likely to concentrate on the inner peripheral side of the coil conductor 32, the gap 52 is provided on the inner peripheral side of the coil conductor 32 being biased towards the inner peripheral side, thereby being able to relieve the residual stress caused by the difference in shrinkage rate during firing between the coil conductor material and the insulating layer material.

[0133] Based on the above, by this embodiment, it is also possible to balance ensuring the strength of the laminate 10 and relieving the residual stress.

[0134] Figure 19 It is a cross-sectional view schematically showing another example of the stacked coil component of Embodiment 2, showing the coil conductor and its vicinity.

[0135] The gap 52 can be provided only at the inner peripheral side end 38 as Figure 18 shown, or can be provided up to the middle between the inner peripheral side front end 38P and the outer peripheral side front end 39P as Figure 19 shown. As Figure 18 and Figure 19 shown, it is preferable not to provide a gap at the outer peripheral side end 39 of the coil conductor 32.

[0136] In this specification, the inner peripheral side end, the outer peripheral side end, and the central portion of the coil conductor refer to Figure 19 the regions R1, R3, and R2 shown. That is, in the cross-section ( Figure 19 ) perpendicular to the extending direction of the coil conductor 32, when the coil conductor 32 is equally divided into three regions in the long side direction (longitudinally in Figure 19 ), the region R1 of the coil conductor 32 located at the innermost peripheral side is called the inner peripheral side end, the region R3 of the coil conductor 32 located at the outermost peripheral side is called the outer peripheral side end, and the central region R2 is called the central portion.

[0137] In addition, in this specification, the gap being biased towards the inner peripheral side of the coil conductor means that, as Figure 19As shown, when observing a cross-section in a direction perpendicular to the extending direction of the coil conductor 32, the shortest distance from the inner peripheral side front end 38P of the coil conductor 32 to the gap 52 is shorter than the shortest distance from the outer peripheral side front end 39P of the coil conductor 32 to the gap 52. In Figure 19 the shown case, the inner peripheral side front end 38P of the coil conductor 32 is adjacent to the gap 52, and the shortest distance from the inner peripheral side front end 38P of the coil conductor 32 to the gap 52 is 0.

[0138] In addition, in this specification, regarding the inner peripheral side front end and the outer peripheral side front end of the coil conductor, as Figure 19 shown, when observing a cross-section in a direction perpendicular to the extending direction of the coil conductor 32, the part 38P located on the innermost peripheral side and the part 39P located on the outermost peripheral side in the coil conductor 32 are respectively referred to as the inner peripheral side front end and the outer peripheral side front end.

[0139] As Figure 18 shown, it is also possible to provide a gap 52 between each of all the coil conductors 32 and the insulating layer 31, biased toward the inner peripheral side of each coil conductor 32.

[0140] In addition, although not shown in the drawings, it is also possible to provide a gap 52 only between a part of the coil conductors 32 and the insulating layer 31, biased toward the inner peripheral side of the coil conductor 32, and not provide a gap between the remaining coil conductors 32 and the insulating layer 31.

[0141] Hereinafter, the results after simulating the stress when an external stress is applied to the laminate 10 of the stacked coil component 1A of Embodiment 2 will be described.

[0142] Figure 20 is a schematic diagram showing the models of Example 5 and Comparative Examples 5 and 6 used in the stress simulation.

[0143] As Figure 20 shown, here, five layers of coil conductors 132 are arranged in any one of the models. In the model of Example 5, gaps 150 are provided only at the inner peripheral side ends 138 of the respective coil conductors 132. In the model of Comparative Example 5, gaps 150 are provided on the entire surface (entire circumference) of all the coil conductors 132. In the model of Comparative Example 6, gaps 150 are provided only at the outer peripheral side ends 139 of the respective coil conductors 132. Other conditions are the same as those of the model Figure 11 shown. For each model, a bending stress is similarly applied to the position (center of the upper surface) indicated by the vertex of the triangle in Figure 20 . Figure 21 And Figure 22 show the results.

[0144] Figure 21This is a diagram showing the results of stress analysis of the models of Example 5 and Comparative Examples 5 and 6. Figure 22 This is a graph showing the stress values of Example 5 and Comparative Examples 5 and 6. In addition, in Figure 22 Figure 22 represents the maximum stress value generated by each model as a relative value with respect to the maximum stress generated by the model of Comparative Example 5.

[0145] From the results, it can be seen that in Comparative Examples 5 and 6 where there are gaps at the outer peripheral side ends of the coil conductors, bending stress is likely to be applied to the outer peripheral side ends of the coil conductors (refer to Figure 21 ). In addition, in order to avoid this stress, it is effective not to provide gaps at the outer peripheral side ends of the coil conductors. In Example 5 where there are only gaps at the inner peripheral side ends of the coil conductors, the stress on the outer peripheral side ends of the coil conductors is transmitted to the coil conductors, thereby being able to relieve stress concentration. As a result, it can be seen that the stress can be significantly relieved.

[0146] In addition, in Embodiments 1 and 2, the gaps provided at various positions are described. However, in this specification, the gaps provided between the coil conductor and the insulating layer only need to be provided in at least a part of the region in the extending direction of the surrounding portion of the coil conductor, and can also be provided in the entire region in the extending direction of the surrounding portion, or can also be provided only in a part of the region in the extending direction of the surrounding portion (which can be one region or multiple regions).

[0147] In addition, in the laminated coil component of the present invention, the presence or absence of a gap between the pad of the coil conductor and the insulating layer is not particularly limited. For example, a gap can also be provided between the surface of the pad of each coil conductor on the side where the via conductor is not connected and the insulating layer. That is, even for the first coil conductor and the second coil conductor, a gap can be provided between the surface of its pad on the side where the via conductor is not connected (the side opposite to the via conductor) and the insulating layer.

[0148] In addition, in Embodiments 1 and 2, the horizontally wound laminated inductor is described. However, the laminated coil component of the present invention can also be a vertically wound laminated inductor in which coils are provided such that the coil axis is orthogonal to the mounting surface.

[0149] Hereinafter, an example of the manufacturing method of the laminated coil component of Embodiments 1 and 2 will be described.

[0150] <Magnetic material manufacturing process>

[0151] First, weigh Fe2O3, ZnO, CuO, and NiO to achieve a specified ratio.

[0152] Next, after putting these weighed substances, pure water, etc. together with PSZ (partially stabilized zirconia) medium into a ball mill for mixing, pulverization is carried out. Regarding the mixing and pulverization time, for example, it is set to be 4 hours or more and 8 hours or less.

[0153] Then, after drying the obtained pulverized material, calcination is carried out. Regarding the calcination temperature, for example, it is set to be 700 °C or more and 800 °C or less. Regarding the calcination time, for example, it is set to be 2 hours or more and 5 hours or less.

[0154] In this way, a powdery magnetic material, more specifically a powdery magnetic ferrite material, is produced.

[0155] The ferrite material is preferably a Ni-Cu-Zn series ferrite material.

[0156] Regarding the Ni-Cu-Zn series ferrite material, when the total amount is set to 100 mol%, it preferably contains 40 mol% or more and 49.5 mol% or less in terms of Fe converted to Fe2O3, 2 mol% or more and 35 mol% or less in terms of Zn converted to ZnO, 6 mol% or more and 13 mol% or less in terms of Cu converted to CuO, and 10 mol% or more and 45 mol% or less in terms of Ni converted to NiO.

[0157] The Ni-Cu-Zn series ferrite material may further contain additives such as Co, Bi, Sn, or Mn.

[0158] The Ni-Cu-Zn series ferrite material may further contain unavoidable impurities.

[0159] <Manufacturing process of green sheet>

[0160] First, after putting the magnetic material, an organic binder such as polyvinyl butyral resin, organic solvents such as ethanol and toluene, and a plasticizer, etc. together with PSZ medium into a ball mill for mixing, pulverization is carried out to produce a slurry.

[0161] Next, after forming the slurry into a sheet with a specified thickness by a doctor blade method or the like and then blanking it into a specified shape, a green sheet is produced. Regarding the thickness of the green sheet, for example, it is set to be 20 μm or more and 30 μm or less. Regarding the shape of the green sheet, for example, it is set to be rectangular.

[0162] As the material of the green sheet, instead of the magnetic material, a non-magnetic material such as borosilicate glass material may also be used, or a mixed material of the magnetic material and the non-magnetic material may be used.

[0163] <Process of forming conductor pattern>

[0164] First, through laser irradiation of a specified part of the green sheet, a through-hole is formed.

[0165] Next, after applying a resin paste to the surface of the green sheet using a screen printing method or the like, a conductive paste such as an Ag paste is filled into the through-hole and applied to the surface of the green sheet using a screen printing method or the like. The resin paste is a paste obtained by containing a resin (such as an acrylic resin) that burns out during firing in a solvent (such as isophorone), and is applied to a predetermined position for forming a void. Thus, for the green sheet, a conductor pattern for a via-hole conductor is formed in the through-hole, and a conductor pattern for a coil conductor connected to the conductor pattern for the via-hole conductor is formed on the surface of the green sheet via a resin pattern for forming a void. Then, a resin paste may be further applied to the conductor pattern for the coil conductor to form a resin pattern for forming a void. In this way, a coil sheet having a conductor pattern for a coil conductor, a conductor pattern for a via-hole conductor, and a resin pattern for forming a void formed on the green sheet is manufactured. A conductor pattern for a coil conductor corresponding to Figure 2 the coil conductor 32 shown and a conductor pattern for a via-hole conductor corresponding to Figure 2 the via-hole conductor 33 (except for the via-hole conductors 33e and 33f) shown are formed on the coil sheet. The resin pattern for forming a void may be substantially the same as the conductor pattern for the coil conductor. In this case, the line width of the resin pattern for forming a void may be set to a width slightly smaller than the line width of the conductor pattern for the coil conductor.

[0166] In addition, the resin paste may not be applied to a predetermined position for forming a void formed in the pad portion. This is because, even in this case, there is a lot of conductive paste in this part, and a void can be formed adjacent to the pad by the shrinkage of this conductive paste.

[0167] Separately, a via-hole sheet is manufactured. A conductor pattern for a via-hole conductor corresponding to Figure 2 the via-hole conductors 33e and 33f shown and a conductor pattern for a pad corresponding to Figure 2 the pads 35e and 35f shown are formed on the via-hole sheet.

[0168] <Manufacturing process of the stacked body block>

[0169] After stacking the coil sheet and the via-hole sheet in the stacking direction (length direction L) in an order corresponding to Figure 2 , thermocompression bonding is performed to manufacture a stacked body block.

[0170] <Manufacturing process of the stacked body and the coil>

[0171] First, the stacked body block is cut into a specified size using a cutting machine or the like to manufacture a singulated chip.

[0172] Next, the singulated chips are fired. Regarding the firing temperature, for example, it is set to be 900 °C or higher and 920 °C or lower. Regarding the firing time, for example, it is set to be 2 hours or longer and 4 hours or shorter.

[0173] When the singulated chips are fired, the green sheets of the coil sheet and the via hole sheet become insulating layers.

[0174] In addition, when the singulated chips are fired, the conductor patterns for the coil conductors, the conductor patterns for the via hole conductors, and the conductor patterns for the pads respectively become coil conductors, via hole conductors, and pads. As a result, a coil is fabricated in which a plurality of coil conductors laminated together with the insulating layer are electrically connected via via hole conductors. In addition, the resin pattern for forming the voids is burned out, and the conductor pattern shrinks more than the green sheet, thereby forming voids.

[0175] Based on the above, a laminate is fabricated in which a plurality of insulating layers are laminated in the stacking direction and a coil is incorporated inside.

[0176] For the laminate, for example, by performing barrel polishing, the corners and ridge lines can be rounded.

[0177] <External electrode forming process>

[0178] First, a conductive paste such as a paste containing Ag and glass powder is applied to the first end face and the second end face of the laminate from which the coil is led out on the outer surface thereof, thereby forming a conductive paste layer.

[0179] Next, by sintering the conductive paste layer, a base electrode of the external electrode is formed. Regarding the sintering temperature, for example, it is set to be 800 °C or higher and 820 °C or lower. Regarding the thickness of the base electrode, for example, it is set to be 5 μm.

[0180] Then, a Ni plating electrode and a Sn plating electrode are sequentially formed on the surface of the base electrode by electroplating or the like. Thereby, an external electrode having a base electrode, a Ni plating electrode, and a Sn plating electrode in this order is formed.

[0181] Based on the above, a laminated coil component is manufactured.

[0182] The following content is disclosed in this specification.

[0183] <1> A laminated coil component, comprising:

[0184] A laminate formed by laminating a plurality of insulating layers and having a coil inside; and

[0185] A first external electrode and a second external electrode electrically connected to the above-mentioned coil,

[0186] The above-mentioned coil is formed by electrically connecting a plurality of coil conductors laminated together with the above-mentioned insulating layer,

[0187] The above coil conductor has three or more layers,

[0188] When observing a cross-section in a direction perpendicular to the direction in which the above coil conductor extends, the cross-sectional shape of the above coil conductor is a flat shape,

[0189] Let the above coil conductor closest to the center of the above laminate in the stacking direction be the first coil conductor,

[0190] A gap is provided between at least one of the above coil conductors other than the above first coil conductor and the above insulating layer,

[0191] No gap is provided between the outer peripheral side end of the above first coil conductor and the above insulating layer.

[0192] <2>The laminated coil component according to <1>, wherein,

[0193] A gap is provided between the single side of all of the above coil conductors other than the above first coil conductor and the above insulating layer.

[0194] <3>The laminated coil component according to <1> or <2>, wherein,

[0195] No gap is provided between the above first coil conductor and the above insulating layer.

[0196] <4>The laminated coil component according to <1> or <2>, wherein,

[0197] A gap is provided between the inner peripheral side end of the above first coil conductor and the above insulating layer.

[0198] <5>The laminated coil component according to <1>, wherein,

[0199] The above coil conductor has four or more layers and an even number of layers,

[0200] Let the above coil conductor next to the above first coil conductor and close to the center of the above laminate in the stacking direction be the second coil conductor,

[0201] A gap is provided between at least one of the above coil conductors other than the above first coil conductor and the above second coil conductor and the above insulating layer,

[0202] No gap is provided between the outer peripheral side end of the above first coil conductor and the above insulating layer, and between the outer peripheral side end of the above second coil conductor and the above insulating layer.

[0203] <6>The stacked coil component according to any one of <1> to <5>, wherein,

[0204] The above-mentioned 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 above-mentioned length direction, and a first side face and a second side face facing each other in the width direction orthogonal to the above-mentioned length direction and the above-mentioned height direction.

[0205] The coil axis of the above-mentioned coil is parallel to the above-mentioned first main face.

[0206] The above-mentioned first main face is the mounting face.

[0207] The interval in the above-mentioned height direction between the above-mentioned coil and the above-mentioned first main face is 43 μm or more.

[0208] <7>A stacked coil component, comprising:

[0209] A laminate formed by laminating a plurality of insulating layers and having a coil inside; and

[0210] A first external electrode and a second external electrode electrically connected to the above-mentioned coil.

[0211] The above-mentioned coil is formed by electrically connecting a plurality of coil conductors laminated together with the above-mentioned insulating layer.

[0212] A gap is provided between at least one of the above-mentioned coil conductors and the above-mentioned insulating layer, biased toward the inner peripheral side of the coil conductor.

[0213] <8>The stacked coil component according to any one of <1> to <7>, wherein,

[0214] The coil axis of the above-mentioned coil is parallel to the mounting face.

Claims

1. A laminated coil component, wherein: have: A laminated body formed by laminating a plurality of insulating layers and having a coil inside; and The first external electrode and the second external electrode are electrically connected to the coil, The coil is formed by electrically connecting a plurality of coil conductors stacked together with the insulating layer, The coil conductor has three or more layers. When observing a cross section in a direction perpendicular to the direction in which the coil conductor extends, the cross-sectional shape of the coil conductor is a flat shape. The coil conductor closest to the center of the stacked body in the stacking direction is set as a first coil conductor, A gap is provided between one surface of at least one of the coil conductors other than the first coil conductor and the insulating layer, No gap is provided between the outer peripheral end portion of the first coil conductor and the insulating layer.

2. The laminated coil component according to claim 1, wherein: A gap is provided between one surface of all the coil conductors except the first coil conductor and the insulating layer.

3. The laminated coil component according to claim 1 or 2, wherein: No gap is provided between the first coil conductor and the insulating layer.

4. The laminated coil component according to claim 1 or 2, wherein: A gap is provided between the inner peripheral end portion of the first coil conductor and the insulating layer.

5. The laminated coil component according to claim 1, wherein The coil conductor has four or more layers and an even number of layers, the coil conductor next to the first coil conductor and located closer to the center of the stacked body in the stacking direction is set as a second coil conductor, A gap is provided between one surface of at least one of the coil conductors other than the first coil conductor and the second coil conductor and the insulating layer, No gap is provided between the outer peripheral end of the first coil conductor and the insulating layer, and no gap is provided between the outer peripheral end of the second coil conductor and the insulating layer.

6. The laminated coil component according to any one of claims 1 to 5, wherein: The stacked body has a first end face and a second end face facing each other in a length direction, a first main face and a second main face facing each other in a height direction orthogonal to the length direction, and a first side face and a second side face facing each other in a width direction orthogonal to the length direction and the height direction. The coil axis of the coil is parallel to the first main surface, The first main surface is a mounting surface, The distance between the coil and the first main surface in the height direction is 43 μm or more.

7. A laminated coil component, wherein: have: A laminated body formed by laminating a plurality of insulating layers and having a coil inside; and The first external electrode and the second external electrode are electrically connected to the coil, The coil is formed by electrically connecting a plurality of coil conductors stacked together with the insulating layer, A gap is provided between at least one of the coil conductors and the insulating layer so as to be offset toward the inner circumference of the coil conductor.

8. The laminated coil component according to claim 1, wherein: The coil axis of the coil is parallel to the mounting surface.

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