Laminated coil component

Abstract

Provided is a laminated coil component having excellent high-frequency characteristics. 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 electrically connected to the coil, the coil being formed by electrically connecting a plurality of coil conductors stacked together with the insulating layer via a conductive conductor penetrating through the insulating layer, the coil conductor including a surrounding portion and a pad connected to the conductive conductor, the laminated body has a first end surface and a second end surface facing each other in a longitudinal direction, a first main surface and a second main surface facing each other in a height direction orthogonal to the longitudinal direction, and a first side surface and a second side surface facing each other in a width direction orthogonal to the longitudinal direction and the height direction, and a coil axis of the coil is parallel to the first main surface. Each of the coil conductors has a first surface facing a first direction parallel to the coil axis and a second surface facing the opposite side of the first direction, and a first gap is provided only between the first surface of the surrounding portion of at least one of the coil conductors 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 electronic component characterized in that a coil is formed inside by stacking a coil conductor and an insulating layer made of a magnetic or non-magnetic material, terminal electrodes are provided at both end portions in the stacking direction, and at least one end-side terminal electrode is connected to a coil end portion inside the stacked body via a conductor filling through-hole provided in one or more insulating layers and a lead-out electrode provided to cover an end portion of the through-hole. The area of the lead-out electrode is set to be 3 times or more the cross-sectional area of the through-hole and 1 / 3 or less of the coil inner area when the stacked body is viewed through in the stacking direction.

[0003] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2002-15918

[0004] As in the stacked electronic component described in Patent Document 1, a stacked coil component in which the coil axis is parallel to the mounting surface (hereinafter, also referred to as a horizontally wound stacked inductor) is a structure suitable for high-frequency applications. However, in a conventional horizontally wound stacked inductor, since the insulating layer between the coil conductors is formed of ferrite having a dielectric constant of about 15, the stray capacitance affects its high-frequency characteristics. In particular, in recent years, higher high-frequency characteristics have been required, and the stray capacitance between adjacent coil conductors hinders the improvement of high-frequency characteristics. Summary of the Invention

[0005] The present invention has been made to solve the above problems, and an object thereof is to provide a stacked coil component having excellent high-frequency characteristics.

[0006] 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 is formed by electrically connecting a plurality of coil conductors stacked together with the insulating layer through a conduction conductor penetrating the insulating layer. The coil conductor includes a surrounding portion and a pad, wherein the pad is connected to the conduction conductor. The stacked body 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 coil conductors each have a first face and a second face, wherein the second face faces a first direction parallel to the coil axis, and the second face faces a side opposite to the first direction. At least one of the surrounding portions of the coil conductors has a first gap only between the first face of the surrounding portion and the insulating layer.

[0007] According to the present invention, a stacked coil component with excellent high-frequency characteristics can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a perspective view schematically showing an example of the stacked coil component of the present invention.

[0009] Figure 2 is schematically showing the composition of Figure 1 an exploded perspective view of an example of the stacked body of the stacked coil component shown.

[0010] Figure 3 is a side view perspectively and schematically showing an example of the internal structure of the stacked body of the stacked coil component shown. Figure 1 an example of the side view perspectively and schematically showing the internal structure of the stacked body of the stacked coil component shown.

[0011] Figure 4 is schematically showing Figure 1 an example of a cross-sectional view of the stacked coil component shown along line A1 - A1.

[0012] Figure 5 is a graph showing the frequency characteristics of the impedance of Example 1 and Comparative Example 1.

[0013] Figure 6 is an enlarged and schematically showing Figure 4 a cross-sectional view near the coil conductor in.

[0014] Figure 7 is a perspective view and schematically showing the composition of Figure 1The figure showing an example of the internal structure of the stacked body of the stacked coil component is a view observed from the second end face side of the stacked body.

[0015] Figure 8 is schematically showing Figure 7 a cross-sectional view showing an example of the cross-section of the stacked coil component shown along line segment A1 - A1.

[0016] Figure 9 is schematically showing the exploded perspective view of another example of the stacked body of the stacked coil component shown Figure 1 in the figure.

[0017] Figure 10 is a schematic diagram showing the test method in the verification of the side clearance amount.

[0018] Explanation of reference numerals

[0019] 1, 81... Stacked coil components; 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 layers; 32, 32a, 32b, 32c, 32d... Coil conductors; 33, 33a, 33b, 33c, 33d, 33e, 33f... Conductive conductors; 34, 34a, 34b, 34c, 34d... Surrounding parts; 35, 35a, 35b, 35c, 35d, 35e, 35f... Pads; 36... First face; 37... Second face; 41... First lead conductor; 42... Second lead conductor; 51... First gap; 52... Second gap; 82... Substrate; 83a, 83b... Support parts; A... Coil axis of the coil; G1... Gap in the height direction between the coil and the first main face; G2... Gap in the height direction between the coil and the second main face. Detailed implementation manners

[0020] Hereinafter, the stacked coil component of the present invention will be described. In addition, the present invention is not limited to the following structures, and can be appropriately changed without departing from the gist of the present invention. Also, a structure formed by combining a plurality of the following described preferred structures is also the present invention.

[0021] The following figures are schematic diagrams, and there are cases where the dimensions, scales of aspect ratios, etc. are different from the actual products. In the figures, the same or corresponding parts are denoted by the same reference numerals. In addition, in each figure, the same elements are denoted by the same reference numerals and repeated explanations are omitted.

[0022] 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 literal strict manner, but also mean substantially equivalent ranges, such as ranges including differences of about several percent.

[0023] Taking each of the following embodiments as an example, of course, partial replacement or combination of the structures shown in different embodiments can be carried out. After the second embodiment, descriptions of matters common to the first embodiment are omitted, and only the differences are described. In particular, the same effects achieved by the same structures will not be mentioned successively in each embodiment.

[0024] Figure 1 It is a perspective view schematically showing an example of the laminated coil component of the present invention.

[0025] Figure 1 The shown laminated coil component 1 includes a laminate (green body) 10, 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 structure of the laminate 10 will be described later, but the laminate 10 is formed by laminating a plurality of insulating layers and a plurality of coil conductors in the lamination 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.

[0026] In the laminated 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

[0027] Here, the length direction L is a direction parallel to the lamination direction.

[0028] 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.

[0029] Although not shown in Figure 1 it, the laminate 10 preferably has rounded corners at the corner portions and the ridge line portions. The corner portion is a portion where three faces of the laminate intersect, and the ridge line portion is a portion where two faces of the laminate intersect.

[0030] For example, as Figure 1As shown, the first external electrode 21 covers 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.

[0031] For example, as Figure 1 shown, the second external electrode 22 covers 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.

[0032] 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 laminate 10 becomes the mounting face.

[0033] 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.

[0034] Similarly, the second external electrode 22 only needs to extend from at least a part of the second end face 12 of the laminate 10 to the mounting face of the laminate 10.

[0035] The first external electrode 21 and the second external electrode 22 can each be either a single-layer structure or a multi-layer structure.

[0036] 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, etc.

[0037] When the first external electrode 21 and the second external electrode 22 are each a multi-layer structure, each external electrode can also have, for example, a base electrode layer containing Ag, a Ni coating, and a Sn coating in this order from the surface side of the laminate 10.

[0038] The size of the laminated coil component of the present invention is not particularly limited, but is preferably 1608 size, 0603 size, 0402 size, or 1005 size.

[0039] Figure 2 is a schematic exploded perspective view showing an example of the laminate constituting the Figure 1 shown laminated coil component.

[0040] As Figure 2As shown, the laminate 10 is formed by laminating a plurality of insulating layers 31a, 31b, 31c, 31d, 31e, and 31f from the first end face 11 side to the second end face 12 side of the laminate 10 in the lamination 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.

[0041] In addition, in this specification, the direction in which a plurality of insulating layers constituting the laminate are laminated is referred to as the lamination direction.

[0042] In Figure 2 the insulating layer 31e is disposed on the lower side in the lamination direction (the first end face 11 side of the laminate 10), and the insulating layer 31f is disposed on the upper side in the lamination direction (the second end face 12 side of the laminate 10).

[0043] Examples of the constituent material of each insulating layer 31 include magnetic materials such as ferrite materials.

[0044] Coil conductors 32a, 32b, 32c, and 32d and conduction conductors 33a, 33b, 33c, and 33d are respectively provided in the insulating layers 31a, 31b, 31c, and 31d. A conduction conductor 33e and a pad 35e are provided in the insulating layer 31e. A conduction 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.

[0045] 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 laminated 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 laminated as one unit (the amount of 3 turns).

[0046] In addition, the coil conductors 32a, 32b, 32c, and 32d respectively include: annular surrounding portions 34a, 34b, 34c, and 34d that are partially vacant with a gap missing at one place and pads 35a, 35b, 35c, and 35d. Pads 35a, 35b, 35c, and 35d are respectively provided at both end portions of each surrounding portion 34a, 34b, 34c, and 34d. Hereinafter, the surrounding portions 34a, 34b, 34c, and 34d will be collectively referred to as the surrounding portion 34.

[0047] The conduction conductors 33a, 33b, 33c, 33d, 33e, and 33f are respectively arranged to penetrate the insulating layers 31a, 31b, 31c, 31d, 31e, and 31f in the stacking direction. Hereinafter, the conduction conductors 33a, 33b, 33c, 33d, 33e, and 33f are also collectively referred to as the conduction conductor 33.

[0048] Above the conduction conductors 33e and 33f, pads 35e and 35f are respectively arranged. The pads 35a, 35b, 35c, 35d, 35e, and 35f are preferably slightly larger than the line widths of the surrounding portions 34a, 34b, 34c, and 34d. Hereinafter, the pads 35a, 35b, 35c, 35d, 35e, and 35f are also collectively referred to as the pad 35. The pad 35 is larger than the adjacent conduction conductor 33, and when observed from the stacking direction (length direction L), the conduction conductor 33 adjacent to the pad 35 is accommodated within the area of the pad 35.

[0049] As the constituent materials of the respective coil conductors 32 and the respective conduction conductors 33 including the surrounding portions 34 and the pads 35, for example, Ag, Au, Cu, Pd, Ni, Al, alloys containing at least one of these metals, etc. can be cited.

[0050] The plurality of insulating layers 31a, 31b, 31c, 31d, 31e, and 31f are stacked in the stacking direction as described above. Thereby, the stacked body 10 is formed, and the plurality of coil conductors 32a, 32b, 32c, and 32d are electrically connected via the conduction 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.

[0051] In addition, the conduction 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 conduction 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 to the first external electrode 21 within the stacked body 10.

[0052] The conduction conductor 33f and the pad 35f become the second lead conductor within the stacked body 10 and are exposed at the second end face 12 of the stacked body 10. That is, the second lead conductor includes the conduction 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 to the second external electrode 22 within the stacked body 10.

[0053] When observed from the stacking direction (length direction L), it is preferable that the coil conductors 32 overlap each other. In addition, when observed from the stacking direction, the coil may also be Figure 2A shape formed by straight portions (e.g., a polygon such as a rectangle), a shape formed by curved portions (e.g., a circle), or a shape formed by straight and curved portions may be used.

[0054] Figure 3 is a side view that perspectively and schematically shows an example of the internal structure of the stacked body of the stacked coil component shown in Figure 1 the figure.

[0055] As Figure 3 shown, in the stacked coil component 1, since a plurality of insulating layers 31 are stacked in the length direction L, the length direction L is the stacking direction. In addition, the stacking direction of the stacked body 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 that serves as the mounting surface. For example, they are parallel to the first main surface 13. That is, the stacked coil component 1 is a horizontally wound stacked inductor in which the coil 30 is arranged such that the coil axis A is parallel to the mounting surface.

[0056] In addition, as Figure 3 shown, actually, no boundary can be visually confirmed between adjacent insulating layers 31.

[0057] The first lead conductor 41 extends in the stacking direction within the stacked body 10 and is linearly connected between the first external electrode 21 provided on the first end surface 11 and the coil conductor 32a opposed to the first external electrode 21. Similarly, the second lead conductor 42 extends in the stacking direction within the stacked body 10 and is linearly connected between the second external electrode 22 provided on the second end surface 12 and the coil conductor 32d opposed to the second external electrode 22.

[0058] In addition, when viewed from the stacking direction (length direction L), it is preferable that the conduction conductors constituting the lead conductors overlap each other, but the conduction conductors constituting the lead conductors may not be strictly arranged in a straight line.

[0059] In addition, in Figure 2 and Figure 3 an example is shown in which the stacking number of the coil conductors 32 for forming 3 turns of the coil 30 is 4, that is, the repeating shape is a 3 / 4 turn shape. However, the stacking number of the coil conductors 32 for forming 1 turn of the coil 30 is not particularly limited.

[0060] For example, the stacking number of the coil conductors 32 for forming 1 turn of the coil 30 may be 2, that is, the repeating shape may be a 1 / 2 turn shape.

[0061] In addition, the stacking number of the coil conductors 32, that is, the stacking number of all the coil conductors 32 included in the stacked body 10 is not particularly limited, but it may be 8 or more and 32 or less.

[0062] Figure 4 is schematically showing Figure 1 a cross-sectional view of an example of a cross-section along line segment A1 - A1 of the stacked coil component shown. In addition, Figure 4 represents a cross-section of the surrounding portion 34 in the coil conductor 32.

[0063] As Figure 4 shown, when observing the cross-section of the coil conductor 32 in a direction perpendicular to the extending direction, the cross-sectional shape of the coil conductor 32 is a flat shape (long-side shape), and its long-side direction is orthogonal to the stacking 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 stacking 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 stacking direction, a trapezoid with different lengths of a pair of opposite sides in the stacking direction, etc.

[0064] In addition, as Figure 4 shown, the coil conductors 32 each have a first surface 36 and a second surface 37. Among them, the first surface 36 faces a first direction parallel to the coil axis A, and the second surface 37 faces the side opposite to the first direction. Both the first surface 36 and the second surface 37 extend along a direction orthogonal to the stacking direction.

[0065] Moreover, only a first gap 51 is provided between the first surface 36 of the surrounding portion 34 of each coil conductor 32 and the insulating layer 31. By forming the first gap 51 in this way, the stray capacitance between adjacent coil conductors 32 can be reduced. Generally, the stray capacitance of a horizontally wound stacked inductor is lower than that of a stacked coil component with the coil axis perpendicular to the mounting surface. However, by providing air with a dielectric constant lower than that of the insulating layer 31 (for example, a ferrite material) in the stacked body 10 as in this embodiment, the stray capacitance can be further reduced. Therefore, the high-frequency characteristics are further improved. Therefore, according to this embodiment, the high-frequency characteristics of the stacked coil component 1 as a horizontally wound stacked inductor can be further improved. In addition, although it is preferable to provide a gap on one side of the surrounding portion 34 of all the coil conductors 32 from the viewpoint of improving the high-frequency characteristics, it is sufficient to provide a gap on one side of the surrounding portion 34 of at least one coil conductor 32. In addition, although the gap can also be interrupted in the middle, from the viewpoint of improving the high-frequency characteristics, it is preferably provided in the entire one side (the entire area of one side) of the coil conductor 32.

[0066] In addition, if gaps are provided on both sides of the first surface 36 and the second surface 37 of each coil conductor 32, the flexural strength during installation of the stacked coil component 1 is reduced, making it vulnerable to impact. Further, in the case of manufacturing such a stacked coil component by the manufacturing method described later, it is necessary to print a resin paste after printing the conductor pattern for the coil conductor, and the manufacturing may become difficult. In contrast, in the stacked coil component 1, a first gap 51 is provided only between the first surface 36 of the surrounding portion 34 of each coil conductor 32 and the insulating layer 31, and no gap is provided between the second surface 37 and the insulating layer 31 or between the side surfaces of the surrounding portion 34 (the inner peripheral side surface and the outer peripheral side surface of the surrounding portion 34) and the insulating layer 31. Therefore, a reduction in the flexural strength during installation of the stacked coil component 1 can be suppressed. Further, the stacked coil component 1 can be easily manufactured by the manufacturing method described later.

[0067] In addition, the gap may be provided only on one side of the surrounding portion 34 of the coil conductor 32, that is, between the first surface 36 and the insulating layer 31 or between the second surface 37 and the insulating layer 31. Alternatively, in some of the coil conductors 32 in which the surrounding portion 34 of the coil conductor 32 has a gap, a first gap 51 may be provided only between the first surface 36 of the surrounding portion 34 of the coil conductor 32 and the insulating layer 31, and in the remaining coil conductors 32, a first gap 51 may be provided only between the second surface 37 of the surrounding portion 34 of the coil conductor 32 and the insulating layer 31.

[0068] In addition, in this specification, the inner peripheral side and the outer peripheral side of the coil conductor (surrounding portion) respectively mean the coil axis side of the coil and the opposite side thereof (the outside of the coil).

[0069] Here, the results of simulating the electrical characteristics of the stacked coil component 1 of the present embodiment will be described. Here, as Example 1 of the stacked coil component 1 of the present embodiment, a model corresponding to a 1608-sized stacked coil component was used. The dimensions of the laminate in the length direction L, width direction W, and height direction T of this model were 1.555 mm, 0.759 mm, and 0.759 mm, respectively. In addition, the thickness of each first gap was 5 μm, and the thickness of each coil conductor was 33 μm. In addition, as Comparative Example 1 with respect to the stacked coil component 1 of the present embodiment, a model that was the same except that the first gap was not provided was used.

[0070] As a result, the stray capacitance of Example 1 was 0.32 pF. In contrast, the stray capacitance of Comparative Example 1 was 0.48 pF, indicating that according to the present embodiment, the stray capacitance can be further reduced.

[0071] Figure 5 It is a graph showing the frequency characteristics of the impedance of Example 1 and Comparative Example 1.

[0072] As Figure 5 shown, the peak impedance of Example 1 is 210 Ω at a frequency of 1000 MHz (= 1 GHz). In contrast, the peak impedance of Comparative Example 1 is 180 Ω at a frequency of 700 MHz. That is, Example 1 corresponds more to high frequencies than Comparative Example 1. In addition, in Example 1, a high impedance is maintained even after 1000 MHz. Therefore, according to the present embodiment, higher frequencies can be corresponded to.

[0073] Figure 6 is an enlarged and schematically showing Figure 4 a cross-sectional view near the coil conductor in

[0074] As Figure 6 shown, the width w1 of the first gap 51 is preferably smaller than the width (line width) W1 of the surrounding portion 34. In this way, by providing the first gap 51 only inside the coil conductor 32, cracks are less likely to enter the insulating layer 31 (e.g., ferrite), resulting in a highly reliable structure. Specifically, the width w1 of the first gap 51 may be in the range of 60% to 90% with respect to the width W1 of the surrounding portion 34. In addition, the width w1 of the first gap 51 and the width W1 of the surrounding portion 34 compared with each other here are the dimensions in the height direction T of the first gap 51 and the surrounding portion 34, respectively, when observing the LT cross-section passing through the coil axis. In addition, the LT cross-section passing through the coil axis refers to a plane parallel to the length direction L and the height direction T of the laminate 10, and is a cross-section cut to pass through the coil axis. In addition, the cross-section cut to pass through the coil axis means a cross-section in which the coil axis and the cut cross-section exist in the same plane.

[0075] In addition, as Figure 6 shown, the thickness T1 of the surrounding portion 34 may be 5 μm or more and 45 μm or less, and the thickness t1 of the first gap 51 may be 1 μm or more and 15 μm or less, or may be 2 μm or more and 5 μm or less. If the first gap 51 is excessively increased, the thickness of the surrounding portion 34 is restricted, and as a result, it may not be possible to achieve a low-resistance laminated coil component. Therefore, by keeping the thickness t1 of the first gap 51 thin within the above range, a laminated coil component with excellent high-frequency characteristics and low resistance can be achieved. Specifically, by making the thickness t1 of the first gap 51 1 μm or more, the high-frequency characteristics of the laminated coil component 1 can be more reliably improved, and by making it 2 μm or more, it can be further improved. In addition, by making the thickness t1 of the first gap 51 15 μm or less, the resistance of the laminated coil component 1 can be reduced, and by making it 5 μm or less, it can be further reduced.

[0076] In addition, the thicknesses t1 and T1 compared with each other here are both the thicknesses measured at the central portion in the line width direction of the surrounding portion 34 when observing the LT cross-section passing through the coil axis.

[0077] Figure 7 is a view that perspectively and schematically shows Figure 1 an example of the internal structure of the laminate constituting the stacked coil component shown, and is a view observed from the second end face side of the laminate. Figure 8 is a schematic view showing Figure 7 an example of a cross-sectional view of the stacked coil component shown along line segment A1 - A1.

[0078] As Figure 7 shown, it is preferable that the width W2 of the pad 35 is greater than the width W1 of the surrounding portion 34. Further, the width W2 of the pad 35 is the dimension in the line width direction of the surrounding portion 34. Additionally, as Figure 8 shown, it is preferable to provide a second gap 52 between the surface of the pad 35 of the coil conductor 32 having the first gap 51 on the side not connected to the conduction conductor 33 and the insulating layer 31, and the second gap 52 is thicker than the first gap 51 (i.e., the thickness t2 of the second gap 52 > the thickness t1 of the first gap 51). Further, the thickness t1 of the first gap 51 compared with the thickness t2 of the second gap 52 here is the thickness measured at the central portion in the line width direction of the surrounding portion 34 when observing the LT cross-section passing through the coil axis. Additionally, the thickness t2 of the second gap 52 compared with the thickness t1 of the first gap 51 is the thickness measured at the central portion in the line width direction of the pad 35 when observing the LT cross-section passing through the center of the pad 35. By providing gaps having thicknesses in this way, the stray capacitance can be further reduced, and thus the high-frequency characteristics of the stacked coil component 1 can be further improved. Additionally, since the width W2 of the pad 35 is greater than the width W1 of the surrounding portion 34, the surface area of the pad 35 can be increased. As a result, it is possible to easily manufacture the second gap 52 that is thicker than the first gap 51.

[0079] As Figure 2 and Figure 7 shown, the first gap 51 may also be provided between the first surface of the entire surrounding portion 34 and the insulating layer 31.

[0080] Here, Figure 7 is used to explain the generation of cracks starting from the first gap in the blank inside the stacked coil component 1 mounted on the substrate.

[0081] As Figure 7 shown, the gap in the height direction between the coil 30 and the first main surface 13 is defined as the side gap G1, and the gap in the height direction between the coil 30 and the second main surface 14 is defined as the side gap G2. Additionally, here, the first main surface 13 is the mounting surface.

[0082] 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 to 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 between the first main surface 13 and the first gap 51 provided on the coil conductor 32 also becomes closer. Moreover, if the side clearance G1 is too small, the first gap 51 approaches the above-mentioned region where stress is particularly applied, and there is a case where cracks are generated inside the green body starting from the first gap 51.

[0083] Therefore, from the viewpoint of suppressing the generation of cracks accompanying the flexure of the substrate, it is preferable to ensure the side clearance G1 to some extent. Specifically, the side clearance G1 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, it is possible to prevent the generation of cracks accompanying the flexure of the substrate. In addition, the upper limit of the side clearance G1 is not particularly limited, but it may be 150 μm or less. Also, the side clearance G2 is not particularly limited, but it may be 43 μm or more and 150 μm or less as in the case of the side clearance G1.

[0084] If the size of the stacked coil component is reduced, the lower limit of the required side clearance G1 is also reduced. Therefore, in the stacked coil component 1 that satisfies the above side clearance G1, it is possible to more effectively prevent the generation of cracks accompanying the flexure of the substrate. From this viewpoint, the size of the stacked coil component 1 is preferably 1608 size or less, and more preferably 1608 size, 1005 size, 0603 size, or 0402 size, for example.

[0085] Generally, in a horizontally wound stacked inductor, there is more conductive paste such as Ag paste at the position where the pad is formed. During manufacturing, a higher pressure is applied than the surrounding portion of the same layer, and there is a tendency for the distance between adjacent coil conductors to be closer than that of the surrounding portion of the same layer.

[0086] Therefore, in the present embodiment, as also shown in Figure 8As shown, in adjacent coil conductors 32, the distance D1 between the opposed pads 35 and the surrounding portions 34 may also be smaller than the distance D2 between two opposed surrounding portions 34. Here, the distance D1 between the opposed pads 35 and the surrounding portions 34, which is compared with the distance D2, is the distance measured at the central portion in the line width direction of the pad 35 when observing the LT cross section passing through the center of the pad 35. In addition, the distance D2 between two opposed surrounding portions 34, which is compared with the distance D1, is the distance measured at the central portion in the line width direction of the surrounding portion 34 when observing the LT cross section passing through the coil axis. Moreover, in this case, it is preferable that second voids 52 are provided between the two pads 35 opposed via the conduction conductor 33 and the insulating layer 31 on the side where the conduction conductor 33 is not connected. Thus, by providing the second voids 52 on both sides of the two pads 35 close to the adjacent coil conductor 32 on the side where the conduction conductor 33 is not connected, the stray capacitance can be effectively further reduced.

[0087] Figure 9 is a schematic diagram showing another example of the laminate constituting Figure 1 the laminate of the stacked coil component shown.

[0088] As Figure 9 shown, the first void 51 may also be provided between the first surface of only a part of the surrounding portions 34 and the insulating layer 31. Thereby, it is possible to achieve both the effect of improving the high-frequency characteristics by reducing the stray capacitance through the first void 51 and the effect of increasing the inductance by making the coil conductor 32 as close as possible to the insulating layer 31 (preferably a magnetic material in this case) in the region where the first void 51 does not exist. In addition, by partially providing the first void 51, compared with the case where the first void 51 is provided on the entire single surface of the surrounding portion 34 (refer to Figure 2 and Figure 7 ), the green body strength can be improved.

[0089] As Figure 9 shown, the first void 51 may also be extended and arranged from near one pad 35 to the middle portion of the surrounding portion 34.

[0090] Hereinafter, an example of the manufacturing method of the stacked coil component of the present invention will be described.

[0091] <Magnetic material production process>

[0092] First, weighing is performed so that Fe2O3, ZnO, CuO, and NiO are in a specified ratio.

[0093] Next, these weighed substances, pure water, etc. are put into a ball mill together with a PSZ (partially stabilized zirconia) medium for mixing and then pulverized. Regarding the mixing / pulverizing time, for example, it is 4 hours or more and 8 hours or less.

[0094] Then, after drying the obtained crushed material, calcination is performed. Regarding the calcination temperature, for example, it is 700 °C or higher and 800 °C or lower. Regarding the calcination time, for example, it is 2 hours or longer and 5 hours or shorter.

[0095] In this way, a powdery magnetic material is produced, and more specifically, a powdery magnetic ferrite material is produced.

[0096] The ferrite material is preferably a Ni-Cu-Zn-based ferrite material.

[0097] The Ni-Cu-Zn-based ferrite material preferably contains, when the total amount is set to 100 mol%, 40 mol% or more and 49.5 mol% or less of Fe in terms of Fe2O3, 2 mol% or more and 35 mol% or less of Zn in terms of ZnO, 6 mol% or more and 13 mol% or less of Cu in terms of CuO, and 10 mol% or more and 45 mol% or less of Ni in terms of NiO.

[0098] The Ni-Cu-Zn-based ferrite material may also contain additives such as Co, Bi, Sn, and Mn.

[0099] The Ni-Cu-Zn-based ferrite material may also contain inevitable impurities.

[0100] <Manufacturing process of green sheet>

[0101] First, the magnetic material, an organic binder such as polyvinyl butyral resin, organic solvents such as ethanol and toluene, a plasticizer, etc. are put into a ball mill together with the PSZ medium for mixing, and then pulverized to produce a raw material.

[0102] Next, the raw material is formed into a sheet with a specified thickness by a doctor blade method or the like, and then blanked into a specified shape to produce a green sheet. Regarding the thickness of the green sheet, for example, it is 20 μm or more and 30 μm or less. Regarding the shape of the green sheet, for example, it is rectangular.

[0103] As the material of the green sheet, instead of the magnetic material, a non-magnetic material such as borosilicate glass material may be used, or a mixed material of a magnetic material and a non-magnetic material may be used.

[0104] <Process of forming conductor pattern>

[0105] First, a via hole is formed by irradiating a specified position of the green sheet with a laser.

[0106] 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 vias and applied to the surface of the green sheet using a screen printing method or the like. The resin paste is obtained by containing a resin (such as an acrylic resin) that disappears during firing in a solvent (such as isophorone), and is applied to the predetermined place for forming voids. Thus, for the green sheet, a conductor pattern for a conduction conductor is formed in the via, and a conductor pattern for a coil conductor connected to the conductor pattern for a conduction conductor is formed on the surface of the green sheet via a resin pattern for forming voids. After that, a resin paste may be further applied to the conductor pattern for a coil conductor to further form a resin pattern for forming voids. In this way, a coil sheet on which a conductor pattern for a coil conductor, a conductor pattern for a conduction conductor, and a resin pattern for forming voids are formed is manufactured. In the coil sheet, a conductor pattern for a coil conductor corresponding to Figure 2 the coil conductor 32 shown and a conductor pattern for a conduction conductor corresponding to Figure 2 the conduction conductor 33 (except for the conduction conductors 33e and 33f) shown are formed. It is preferable that the resin pattern for forming voids is almost the same as the conductor pattern for a coil conductor, and the line width of the resin pattern for forming voids is made slightly smaller than the line width of the conductor pattern for a coil conductor.

[0107] In addition, the resin paste may not be applied to the predetermined place for forming the second void 52 in the pad portion. This is because even in this case, there is a large amount of conductive paste at this position, and the second void 52 can be formed by the shrinkage of the conductive paste.

[0108] Separately from the coil sheet, a conduction sheet on which a conductor pattern for a conduction conductor corresponding to Figure 2 the conduction conductors 33e and 33f shown and a conductor pattern for a pad corresponding to Figure 2 the pads 35e and 35f shown are formed is manufactured.

[0109] <Manufacturing process of the laminated body block>

[0110] After laminating the coil sheet and the conduction sheet in the lamination direction (length direction L) in the order corresponding to Figure 2 , hot pressing is performed to manufacture a laminated body block.

[0111] <Manufacturing process of the laminated body and the coil>

[0112] First, the laminated body block is cut into a specified size using a cutting machine or the like, thereby manufacturing a singulated chip.

[0113] Next, the singulated chip is fired. Regarding the firing temperature, for example, it is 900 °C or higher and 920 °C or lower. Regarding the firing time, for example, it is 2 hours or longer and 4 hours or shorter.

[0114] When the individual chips are fired, the green sheets of the coil sheet and the conductive sheet serve as insulating layers.

[0115] In addition, when the singulated chip is fired, the conductor pattern for coil conductor, the conductor pattern for via conductor, and the conductor pattern for pad become coil conductor, via conductor, and pad, respectively. As a result, a coil is produced in which a plurality of coil conductors stacked together with an insulating layer are electrically connected via via conductors. In addition, the void-forming resin pattern disappears and the conductor pattern shrinks compared to the green sheet, thereby forming a void.

[0116] Through the above, a laminated body is produced in which a plurality of insulating layers are laminated in the lamination direction and the coil is built in the interior.

[0117] The laminate may be rounded at its corners and ridges by, for example, performing barrel polishing.

[0118] <External electrode formation process>

[0119] First, a conductive paste such as a paste containing Ag and glass frit is applied to the first end surface and the second end surface of the outer surface of the laminate to which the coil is led, thereby forming a conductive paste layer.

[0120] Next, the conductive paste layer is fired to form a base electrode of the external electrode. The firing temperature is, for example, 800° C. to 820° C. The thickness of the base electrode is, for example, 5 μm.

[0121] Then, a Ni-plated electrode and a Sn-plated electrode are sequentially formed on the surface of the base electrode by electrolytic plating, etc. Thus, an external electrode having the base electrode, the Ni-plated electrode, and the Sn-plated electrode in this order is formed.

[0122] Through the above, a laminated coil component is manufactured.

[0123] Hereinafter, the results of verifying the side clearance amount that does not cause cracks in the base body of the laminated coil component according to the present embodiment will be described.

[0124] As samples, 15 laminated coil components were fabricated by the above manufacturing method. The amounts of side gaps G1 and G2 of the laminated coil components, which have a first gap only between the first surface of the surrounded portion and the insulating layer in the surrounded portion of all coil conductors, were different from each other. All the laminated coil components were of the 1608 size. The dimensions of the 15 samples were measured and the average values were obtained. The dimensions of the laminated coil component including the external electrodes in the length direction L, width direction W, and height direction T were 1.530 mm, 0.822 mm, and 0.822 mm, respectively. The dimensions of the laminate excluding the external electrodes in the length direction L, width direction W, and height direction T were 1.372 mm, 0.783 mm, and 0.783 mm, respectively.

[0125] Figure 10 It is a schematic diagram showing the test method in the verification of the side gap amount.

[0126] As Figure 10 shown, first, the laminated coil component 81 as a sample was mounted on the substrate 82 with the first main surface as the mounting surface, and the substrate 82 was supported at the support portions 83a and 83b located at positions 45 mm from the center of the laminated coil component 81 in the length direction, so that the laminated coil component 81 was on the lower side. Then, at the central portion of the laminated coil component 81, stress was applied from the back surface of the substrate 82 on which the laminated coil component 81 was not mounted until the deflection amount of the substrate 82 was 3 mm, and it was confirmed whether cracks were generated inside the green body of the laminated coil component 81. In addition, although a deflection amount of 2 mm is sufficient in practice, here the test was conducted with 3 mm in order to leave more margin. The results are shown in Table 1 below.

[0127] [Table 1]

[0128] Sample Number G1 (μm) G2 (μm) Presence 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

[0129] From these results, it can be seen that the side gap G1 is preferably 43 μm or more, more preferably 44 μm or more, and further preferably 46 μm or more.

[0130] The following content is disclosed in this specification.

[0131] <1> A laminated coil component, comprising:

[0132] A laminate formed by laminating a plurality of insulating layers and having a coil inside; and

[0133] A first external electrode and a second external electrode electrically connected to the above coil,

[0134] The above coil is formed by electrically connecting a plurality of coil conductors laminated together with the above insulating layer through a conduction conductor passing through the above insulating layer,

[0135] The above-mentioned coil conductor includes a surrounding portion and a pad, wherein the above-mentioned pad is connected to the above-mentioned conducting conductor.

[0136] 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.

[0137] The coil axis of the above-mentioned coil is parallel to the above-mentioned first main face.

[0138] The above-mentioned coil conductors each have a first face and a second face, wherein the above-mentioned first face faces a first direction parallel to the above-mentioned coil axis, and the above-mentioned second face faces the side opposite to the above-mentioned first direction.

[0139] For at least one of the above-mentioned coil conductors, the above-mentioned surrounding portion has a first gap only between the first face of the surrounding portion and the above-mentioned insulating layer.

[0140] <2>The laminated coil component according to <1>, wherein,

[0141] For all of the above-mentioned coil conductors, the above-mentioned surrounding portion has the above-mentioned first gap only between the first face of the surrounding portion and the above-mentioned insulating layer.

[0142] <3>The laminated coil component according to <1>, wherein,

[0143] For at least one of the above-mentioned coil conductors, the above-mentioned surrounding portion has the above-mentioned first gap only between the first face of the surrounding portion and the above-mentioned insulating layer or only between the second face of the surrounding portion and the above-mentioned insulating layer.

[0144] For some of the above-mentioned coil conductors, the above-mentioned surrounding portion has the above-mentioned first gap only between the first face of the surrounding portion of the coil conductor and the above-mentioned insulating layer.

[0145] For the remaining above-mentioned coil conductors, the above-mentioned first gap is provided only between the second face of the surrounding portion of the coil conductor and the above-mentioned insulating layer.

[0146] <4>The laminated coil component according to <3>, wherein,

[0147] For all of the above-mentioned coil conductors, the above-mentioned surrounding portion has the above-mentioned first gap only between the first face of the surrounding portion and the above-mentioned insulating layer or only between the second face of the surrounding portion and the above-mentioned insulating layer.

[0148] For some of the above-mentioned coil conductors, the above-mentioned surrounding portion has the above-mentioned first gap only between the first face of the surrounding portion of the coil conductor and the above-mentioned insulating layer.

[0149] All the remaining above-mentioned coil conductors are provided with the above-mentioned first gap only between the second surface of the surrounding portion of the coil conductor and the above-mentioned insulating layer.

[0150] <5> The stacked coil component according to any one of <1> to <4>, wherein

[0151] The width of the above-mentioned first gap is smaller than the width of the above-mentioned surrounding portion.

[0152] <6> The stacked coil component according to any one of <1> to <5>, wherein

[0153] The width of the above-mentioned pad is larger than the width of the above-mentioned surrounding portion,

[0154] A second gap is provided between the surface of the pad of the coil conductor provided with the above-mentioned first gap on the side not connected to the above-mentioned conduction conductor and the above-mentioned insulating layer,

[0155] The above-mentioned second gap is thicker than the above-mentioned first gap.

[0156] <7> The stacked coil component according to any one of <1> to <6>, wherein

[0157] The above-mentioned first gap is provided between the first surface of only a part of the above-mentioned surrounding portion and the above-mentioned insulating layer.

[0158] <8> The stacked coil component according to any one of <1> to <7>, wherein

[0159] In the adjacent above-mentioned coil conductors, the distance between the opposed above-mentioned pads and the above-mentioned surrounding portion is smaller than the distance between the two opposed above-mentioned surrounding portions,

[0160] Second gaps are provided between the surfaces of the two pads opposed via the above-mentioned conduction conductor on the side not connected to the above-mentioned conduction conductor and the above-mentioned insulating layer.

[0161] <9> The stacked coil component according to any one of <1> to <8>, wherein

[0162] The thickness of the above-mentioned first gap is 1 μm or more and 15 μm or less.

[0163] <10> The stacked coil component according to any one of <1> to <9>, wherein

[0164] The above-mentioned first main surface is the mounting surface,

[0165] The interval between the above-mentioned coil and the above-mentioned first main surface in the above-mentioned height direction is 43 μm or more.

Claims

1. A laminated coil component comprising: 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 via a conducting conductor penetrating the insulating layer. The coil conductor comprises a surrounding portion and a pad, wherein: The pad is connected to the via conductor. 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 perpendicular to the length direction, and a first side face and a second side face facing each other in a width direction perpendicular to the length direction and the height direction. The coil axis of the coil is parallel to the first main surface. The coil conductor has a first surface and a second surface, respectively, wherein the first surface faces a first direction parallel to the coil axis, and the second surface faces a side opposite to the first direction. The surrounding portion of at least one of the coil conductors has a first gap only between the first surface of the surrounding portion and the insulating layer.

2. The laminated coil component according to claim 1, wherein: The surrounding portion of all the coil conductors has the first gap only between the first surface of the surrounding portion and the insulating layer.

3. The laminated coil component according to claim 1, wherein The surrounding portion of at least one of the coil conductors has the first gap only between the first surface of the surrounding portion and the insulating layer or only between the second surface of the surrounding portion and the insulating layer. A portion of the coil conductor has the first gap only between the first surface of the surrounding portion of the coil conductor and the insulating layer. The remaining coil conductor has the first gap only between the second surface of the surrounding portion of the coil conductor and the insulating layer.

4. The laminated coil component according to claim 3, wherein: The above-mentioned surrounding portion of all the above-mentioned coil conductors is provided with the above-mentioned first gap only between the first surface of the surrounding portion and the above-mentioned insulating layer or only between the second surface of the surrounding portion and the above-mentioned insulating layer. A portion of the coil conductor has the first gap only between the first surface of the surrounding portion of the coil conductor and the insulating layer. Among them, all the remaining coil conductors are provided with the first gap only between the second surface of the surrounding portion of the coil conductor and the insulating layer.

5. The laminated coil component according to any one of claims 1 to 4, wherein The width of the first gap is smaller than the width of the surrounding portion.

6. The laminated coil component according to any one of claims 1 to 5, wherein The width of the pad is greater than the width of the surrounding portion. The pad of the coil conductor provided with the first gap has a second gap provided between a surface not connected to the via conductor and the insulating layer. The second gap is thicker than the first gap.

7. The laminated coil component according to any one of claims 1 to 6, wherein The first gap is provided between only a portion of the first surface of the surrounding portion and the insulating layer.

8. The laminated coil component according to any one of claims 1 to 7, wherein In the adjacent coil conductors, the distance between the opposing pads and the surrounding portions is smaller than the distance between the two opposing surrounding portions. A second gap is provided between the insulating layer and the surface of each of the two pads that are opposed to each other via the via conductor.

9. The laminated coil component according to any one of claims 1 to 8, wherein The first gap has a thickness of 1 μm or more and 15 μm or less.

10. The laminated coil component according to any one of claims 1 to 9, wherein The first main surface is a mounting surface. A distance between the coil and the first main surface in the height direction is 43 μm or more.

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