Multilayer coil component

Abstract

To provide a laminated coil component which can be miniaturized and is excellent in low-frequency characteristics.SOLUTION: The multilayer coil component 1 includes the multilayer body 10, which is formed by stacking the plurality of insulating layers 31 in the length direction x and contains the coil 30, and the outer electrodes 21 and 22. In the coil, a plurality of coil conductors 32 are laminated in the length direction together with an insulating layer and are electrically connected, and the laminated body has end surfaces 11 and 12 facing each other in the length direction, main surfaces 13 and 14 facing each other in the height direction, and side surfaces facing each other in the width direction z. The lamination direction of the laminated body and the coil axis direction A of the coil are parallel to the main surface, and the first main surface 13 is a mounting surface. Dimensions B _ W, B _ T, and B _ L of the multilayer body 10 in the widthwise, heightwise, and lengthwise directions satisfy B _ W ≤ 200 μ m, B _ L ≤ 400 μ m, and 200 μm ≤ B _ T or B _ T ≤ 200 μ m, B _ L ≤ 400 μ m, and 200 μm ≤ B _ W, respectively, and the inside diameter area of the coil 30 is 7500 μ m2 or more.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] As a multilayer coil component, for example, Patent Document 1 discloses a multilayer coil component of 0603 size. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-82190 Summary of the Invention [Problem to be solved by the invention]

[0004] In response to the recent trend toward smaller electrical devices, there is a demand for smaller multilayer coil components. However, for example, if the multilayer coil component described in Patent Document 1 is simply miniaturized to an 0402 size, there is a risk that the low-frequency characteristics, specifically the transmission coefficient S21 (S21 characteristics) in the low-frequency band, will become insufficient.

[0005] The present invention has been made to solve the above problems, and an object of the present invention is to provide a multilayer coil component that can be miniaturized and has excellent low-frequency characteristics. [Means for solving the problem]

[0006] The multilayer coil component of the present invention includes a laminate formed by laminating a plurality of insulating layers in the length direction and having a coil built therein, and a first external electrode and a second external electrode electrically connected to the coil, wherein the coil is formed by electrically connecting a plurality of coil conductors laminated together with the insulating layers in the length direction, and the laminate has first and second end faces opposing each other in the length direction, first and second main faces opposing each other in a height direction perpendicular to the length direction, and a width direction perpendicular to the length direction and the height direction. a first side surface and a second side surface facing each other in a direction perpendicular to the surface of the laminate, a stacking direction of the laminate and a coil axis direction of the coil are parallel to the first main surface, the first main surface is a mounting surface, dimensions of the laminate in the width direction, the height direction and the length direction are defined as B_W, B_T and B_L, respectively, and the laminate satisfies B_W≦200 μm, B_L≦400 μm and 200 μm≦B_T, or B_T≦200 μm, B_L≦400 μm and 200 μm≦B_W, and an inner diameter area of ​​the coil is 7500 μm 2 The present invention is characterized in that: [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a multilayer coil component that can be miniaturized and has excellent low-frequency characteristics. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view schematically illustrating an example of the multilayer coil component according to the first embodiment. [Figure 2A] FIG. 2A is a side view of the multilayer coil component shown in FIG. [Figure 2B] FIG. 2B is a front view of the multilayer coil component shown in FIG. [Figure 2C] FIG. 2C is a bottom view of the multilayer coil component shown in FIG. [Figure 3] FIG. 3 is a cross-sectional view schematically illustrating an example of the multilayer coil component according to the first embodiment. [Figure 4]FIG. 4 is an exploded perspective view showing the insulating layers that constitute the multilayer coil component shown in FIG. [Figure 5] FIG. 5 is an exploded plan view showing the insulating layers that constitute the multilayer coil component shown in FIG. [Figure 6] FIG. 6 is a plan view schematically showing another example of the repeated shape of the coil conductors that constitute the multilayer coil component shown in FIG. [Figure 7] FIG. 7 is a plan view schematically showing another example of the repeated shape of the coil conductors that constitute the multilayer coil component shown in FIG. [Figure 8] FIG. 8 is a plan view schematically showing another example of the repeated shape of the coil conductors that constitute the multilayer coil component shown in FIG. [Figure 9] FIG. 9 is a plan view schematically showing the repeated shape of the coil conductors that constitute the multilayer coil component shown in FIG. [Figure 10] FIG. 10 is a perspective view schematically illustrating an example of the multilayer coil component according to the second embodiment. [Figure 11A] 11A is a side view of the multilayer coil component shown in FIG. [Figure 11B] FIG. 11B is a front view of the multilayer coil component shown in FIG. [Figure 11C] 11C is a bottom view of the multilayer coil component shown in FIG. [Figure 12] FIG. 12 is a cross-sectional view schematically illustrating an example of the multilayer coil component according to the second embodiment. [Figure 13] FIG. 13 is an exploded plan view showing the insulating layers that constitute the multilayer coil component shown in FIG. [Figure 14] FIG. 14 is a diagram showing a schematic diagram of a method for measuring the transmission coefficient S21. [Figure 15] FIG. 15 is a graph showing the transmission coefficient S21 of Samples 1 to 4. [Figure 16] FIG. 16 is a graph showing the transmission coefficient S21 of Samples 4 to 7. [Figure 17]FIG. 17 is a graph showing the relationship between the transmission coefficient S21 at 1 GHz and the inner diameter area of ​​the coil for each sample. DETAILED DESCRIPTION OF THE INVENTION

[0009] The laminated coil component of the present invention will be described below. However, the present invention is not limited to the following embodiments and can be applied by making appropriate modifications within the scope of the present invention. Note that the present invention also includes a combination of two or more of the individual desirable configurations described below.

[0010] The drawings shown below are schematic diagrams, and the dimensions, aspect ratio, and other scales may differ from those of the actual product. In the drawings, the same or equivalent parts will be designated by the same reference numerals. In addition, the same elements will be designated by the same reference numerals in each drawing, and duplicate explanations will be omitted.

[0011] In this specification, terms indicating the relationship between elements (e.g., "parallel," "orthogonal," etc.) and terms indicating the shape of elements not only mean the literal and strict form, but also mean a range that is substantially equivalent, for example, a range that includes a difference of about a few percent.

[0012] The following embodiments are merely examples, and it goes without saying that partial substitution or combination of the configurations shown in different embodiments is possible. From the second embodiment onwards, descriptions of matters common to the first embodiment will be omitted, and only differences will be described. In particular, similar effects resulting from similar configurations will not be mentioned in each embodiment.

[0013] (Embodiment 1) FIG. 1 is a perspective view schematically illustrating an example of the multilayer coil component according to the first embodiment. 2A is a side view of the multilayer coil component shown in FIG. 1, FIG. 2B is a front view of the multilayer coil component shown in FIG. 1, and FIG. 2C is a bottom view of the multilayer coil component shown in FIG.

[0014] The multilayer coil component 1 shown in FIGS. 1, 2A, 2B, and 2C includes a laminate 10, a first external electrode 21, and a second external electrode 22. The laminate 10 has a roughly rectangular parallelepiped shape with six sides. The configuration of the laminate 10 will be described later; it is formed by stacking multiple insulating layers in the longitudinal direction and has a coil built in. The first external electrode 21 and the second external electrode 22 are each electrically connected to the coil.

[0015] In the multilayer coil component and laminate of the present invention, the length direction, height direction, and width direction are defined as the x direction, y direction, and z direction in Fig. 1. Here, the length direction (x direction), height direction (y direction), and width direction (z direction) are perpendicular to one another.

[0016] As shown in Figures 1, 2A, 2B, and 2C, the laminate 10 has a first end face 11 and a second end face 12 that face each other in the length direction (x direction), a first main face 13 and a second main face 14 that face each other in the height direction (y direction) perpendicular to the length direction, and a first side face 15 and a second side face 16 that face each other in the width direction (z direction) perpendicular to the length direction and height direction.

[0017] Although not shown in Fig. 1, the corners and ridges of the laminate 10 are preferably rounded. A corner is a portion where three surfaces of the laminate intersect, and a ridge is a portion where two surfaces of the laminate intersect.

[0018] As shown in Figures 1, 2A, 2B, and 2C, 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 part of the first main surface 13, part of the second main surface 14, part of the first side surface 15, and part of the second side surface 16. In addition, 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 part of the first main surface 13, part of the second main surface 14, part of the first side surface 15, and part of the second side surface 16.

[0019] Since the first external electrodes 21 and the second external electrodes 22 are arranged as described above, when the multilayer coil component 1 is mounted on a substrate, any one of the first main surface 13, the second main surface 14, the first side surface 15, and the second side surface 16 of the laminate 10 can serve as the mounting surface, but in this embodiment, the first main surface 13 is used as the mounting surface.

[0020] However, it is sufficient that the first external electrode 21 extends from at least a part of the first end face 11 of the laminate 10 to the mounting surface of the laminate 10 .

[0021] Similarly, the second external electrode 22 may extend from at least a portion of the second end face 12 of the laminate 10 to the mounting surface of the laminate 10 .

[0022] The size of the multilayer coil component of the present invention is not particularly limited, but it is preferably 0402 size or a size similar thereto.

[0023] More specifically, if the dimensions of the laminate in the width direction (z direction), height direction (y direction), and length direction (x direction) are B_W (the length indicated by the double-headed arrow B_W in FIG. 2C ), B_T (the length indicated by the double-headed arrow B_T in FIG. 2B ), and B_L (the length indicated by the double-headed arrow B_L in FIG. 2A ), respectively, the laminate satisfies B_W≦200 μm, B_L≦400 μm, and 200 μm≦B_T. Note that in the present disclosure, when simply referring to the laminate 10, the first external electrode 21 and the second external electrode 22 are not included in the laminate 10. Therefore, B_W, B_W, and B_T all refer to dimensions that do not include the first external electrode 21 and the second external electrode 22.

[0024] The laminate preferably satisfies 160 μm≦B_W≦200 μm, and more preferably 170 μm≦B_W≦190 μm. The laminate also preferably satisfies 340 μm≦B_L≦380 μm, and more preferably 350 μm≦B_L≦370 μm. Furthermore, the laminate preferably satisfies 210 μm≦B_T≦300 μm, and more preferably 260 μm≦B_T≦300 μm.

[0025] Furthermore, if the dimensions of the laminated coil component in the width direction (z direction), height direction (y direction), and length direction (x direction) are W (the length indicated by the double-headed arrow W in FIG. 2C ), T (the length indicated by the double-headed arrow T in FIG. 2B ), and L (the length indicated by the double-headed arrow L in FIG. 2A ), respectively, the laminated coil component preferably satisfies 180 μm≦W≦220 μm, and more preferably satisfies 190 μm≦W≦210 μm. Furthermore, the laminated coil component preferably satisfies 380 μm≦L≦420 μm, and more preferably satisfies 390 μm≦L≦410 μm. Furthermore, the laminated coil component preferably satisfies 230 μm≦T≦320 μm, and more preferably satisfies 270 μm≦T≦310 μm.

[0026] In this way, the multilayer coil component of the present invention is compatible with miniaturization in the sense of reducing the mounting area.

[0027] The coils built into the laminates that constitute the multilayer coil component of the present invention will now be described. The coil is formed by electrically connecting a plurality of coil conductors stacked in the longitudinal direction together with insulating layers.

[0028] FIG. 3 is a cross-sectional view schematically showing an example of the laminated coil component of embodiment 1, FIG. 4 is an exploded perspective view schematically showing the state of insulating layers constituting the laminated coil component shown in FIG. 3, and FIG. 5 is an exploded plan view schematically showing the state of insulating layers constituting the laminated coil component shown in FIG. 3. 3 is a schematic diagram showing the insulating layers, coil conductors, connecting conductors, and the stacking direction of the laminate, and does not strictly represent the actual shapes and connections, etc. For example, the coil conductors are connected through via conductors.

[0029] As shown in FIG. 3, the multilayer coil component 1 includes a laminate 10 incorporating a coil 30 formed by electrically connecting a plurality of coil conductors 32 stacked together with insulating layers 31, and a first external electrode 21 and a second external electrode 22 electrically connected to the coil 30. The laminate 10 has a region where the coil conductors 32 are arranged and a region where the connecting conductors 41 or 42 are arranged. The stacking direction of the laminate 10 and the axial direction of the coil (indicated by coil axis A in FIG. 3) are parallel to the first main surface 13.

[0030] In this specification, the direction in which the insulating layers constituting the laminate are stacked is referred to as the stacking direction. Furthermore, as shown in FIG. 3, no boundary between adjacent insulating layers 31 is actually visible.

[0031] 4 and 5, the laminate 10 has insulating layer 31a, insulating layer 31b, insulating layer 31c, and insulating layer 31d as the insulating layer 31 in Fig. 3. The laminate 10 has insulating layer 35a1, insulating layer 35a2, insulating layer 35a3, and insulating layer 35a4 as the insulating layer 35a in Fig. 3. The laminate 10 has insulating layer 35b1, insulating layer 35b2, insulating layer 35b3, and insulating layer 35b4 as the insulating layer 35b in Fig. 3.

[0032] The constituent material of each insulating layer may be, for example, a magnetic material such as a ferrite material, but a mixed material of a ferrite material and a non-magnetic material having a lower dielectric constant than that of the ferrite material is particularly preferred, which can improve the high-frequency characteristics of the multilayer coil component of the present invention. The ferrite material may be, for example, a Ni-Zn-Cu based ferrite material. Examples of non-magnetic materials having a lower dielectric constant than ferrite materials include glass ceramics and willemite.

[0033] The coil 30 has a coil conductor 32a, a coil conductor 32b, a coil conductor 32c, and a coil conductor 32d as the coil conductor 32 in FIG.

[0034] The coil conductor 32a, the coil conductor 32b, the coil conductor 32c, and the coil conductor 32d are disposed on the main surfaces of the insulating layer 31a, the insulating layer 31b, the insulating layer 31c, and the insulating layer 31d, respectively.

[0035] The length of the coil conductor 32a, the coil conductor 32b, the coil conductor 32c, and the coil conductor 32d is each ¾ of the length of the turn of the coil 30. In other words, the number of stacked coil conductors required to form the three turns of the coil 30 is four. In the laminate 10, the coil conductors 32a, the coil conductor 32b, the coil conductor 32c, and the coil conductor 32d are stacked repeatedly as one unit (three turns).

[0036] The coil conductor 32a has a line portion 36a and a land portion 37a arranged at the end of the line portion 36a. The coil conductor 32b has a line portion 36b and a land portion 37b arranged at the end of the line portion 36b. The coil conductor 32c has a line portion 36c and a land portion 37c arranged at the end of the line portion 36c. The coil conductor 32d has a line portion 36d and a land portion 37d arranged at the end of the line portion 36d. Hereinafter, the line portions 36a, 36b, 36c, and 36d will also be collectively referred to as the line portions 36.

[0037] Via conductors 33a, 33b, 33c, and 33d are arranged in insulating layer 31a, insulating layer 31b, insulating layer 31c, and insulating layer 31d, respectively, so as to penetrate through them in the stacking direction.

[0038] Insulating layer 31a with coil conductor 32a and via conductor 33a, insulating layer 31b with coil conductor 32b and via conductor 33b, insulating layer 31c with coil conductor 32c and via conductor 33c, and insulating layer 31d with coil conductor 32d and via conductor 33d are repeatedly stacked as a single unit. As a result, land portion 37a of coil conductor 32a, land portion 37b of coil conductor 32b, land portion 37c of coil conductor 32c, and land portion 37d of coil conductor 32d are connected via via conductor 33a, via conductor 33b, via conductor 33c, and via conductor 33d. In other words, the lands of coil conductors adjacent in the stacking direction are connected to each other via the via conductors.

[0039] As a result of the above, the solenoid coil 30 built into the laminate 10 is formed.

[0040] Examples of materials that can be used to form each of the coil conductors and each of the via conductors include Ag, Au, Cu, Pd, Ni, Al, and alloys containing at least one of these metals.

[0041] The shape of the coil conductors 32 when viewed through the stacking direction is not particularly limited, and may be a square, but is preferably a rectangle. In this case, the shape of each coil conductor 32 may be a square with some open sides, but is more preferably a rectangle with some open sides. This makes it possible to effectively increase the inner diameter area of ​​the coil 30 while ensuring a side gap.

[0042] Thus, in this specification, "rectangle" refers to a quadrilateral with four equal corners that is not a square. Also, "rectangle" refers to a quadrilateral with four equal corners, including a square.

[0043] When viewed in a plane from the stacking direction, it is preferable that the diameters of land portions 37a, 37b, 37c, and 37d are larger than the line widths of line portions 36a, 36b, 36c, and 36d, respectively, as shown in FIG. 5.

[0044] When viewed from above in the stacking direction, the land portions 37a, 37b, 37c, and 37d may each have a circular shape as shown in FIG. 5, or a polygonal shape.

[0045] Via conductors 33p are arranged to penetrate each of insulating layers 35a1, 35a2, 35a3, and 35a4 in the stacking direction. Land portions connected to via conductors 33p may be arranged on the main surfaces of insulating layers 35a1, 35a2, 35a3, and 35a4.

[0046] The insulating layer 35a1 with the via conductor 33p, the insulating layer 35a2 with the via conductor 33p, the insulating layer 35a3 with the via conductor 33p, and the insulating layer 35a4 with the via conductor 33p are stacked so as to overlap the coil conductor 32a and the insulating layer 31a with the via conductor 33a. As a result, the via conductors 33p are connected to each other to form a first connecting conductor 41, and the first connecting conductor 41 is exposed at the first end face 11. As a result, the first external electrode 21 and the coil 30 are connected to each other via the first connecting conductor 41.

[0047] As described above, the first connecting conductor 41 preferably connects the first external electrode 21 and the coil 30 in a straight line. The first connecting conductor 41 connecting the first external electrode 21 and the coil 30 in a straight line means that the via conductors 33p constituting the first connecting conductor 41 overlap each other when viewed in a plan view from the stacking direction, and the via conductors 33p do not have to be arranged in a strict straight line.

[0048] Via conductors 33q are arranged to penetrate through insulating layers 35b1, 35b2, 35b3, and 35b4 in the stacking direction. Land portions connected to via conductors 33q may be arranged on the main surfaces of insulating layers 35b1, 35b2, 35b3, and 35b4.

[0049] The insulating layer 35b1 with the via conductor 33q, the insulating layer 35b2 with the via conductor 33q, the insulating layer 35b3 with the via conductor 33q, and the insulating layer 35b4 with the via conductor 33q are stacked so as to overlap the coil conductor 32d and the insulating layer 31d with the via conductor 33d. As a result, the via conductors 33q are connected to each other to form a second connecting conductor 42, and the second connecting conductor 42 is exposed at the second end face 12. As a result, the second external electrode 22 and the coil 30 (coil conductor 32d) are connected to each other via the second connecting conductor 42.

[0050] As described above, the second connecting conductor 42 preferably connects the second external electrode 22 and the coil 30 in a straight line. The second connecting conductor 42 connecting the second external electrode 22 and the coil 30 in a straight line means that the via conductors 33q constituting the second connecting conductor 42 overlap each other when viewed in a plan view from the stacking direction, and the via conductors 33q do not have to be arranged in a strict straight line.

[0051] Figures 4 and 5 illustrate an example in which the number of layers of the coil conductor to form three turns of the coil 30 is four, i.e., the repeating shape is a 3 / 4 turn shape, but the number of layers of the coil conductor to form one turn of the coil is not particularly limited. For example, the number of layers of the coil conductor for forming one turn of the coil may be two, that is, the repeating shape may be a 1 / 2 turn shape.

[0052] The number of turns (windings) of the coil 30 is not particularly limited, but from the viewpoint of improving low-frequency characteristics, it is preferably 10 turns or more, more preferably 15 turns or more, and even more preferably 20 turns or more. The number of turns of the coil 30 is preferably 35 turns or less, more preferably 30 turns or less, and even more preferably 25 turns or less.

[0053] When viewed in a plane from the stacking direction, the coil conductors constituting the coil preferably overlap each other. Furthermore, when viewed in a plane from the stacking direction, the shape of the coil (coil conductor) is preferably rectangular (more preferably rectangular). Note that if the coil includes a land portion, the shape excluding the land portion (i.e., the shape of the line portion) is the shape of the coil (coil conductor).

[0054] Fig. 6 to Fig. 8 are plan views each schematically showing another example of the repeating shape of the coil conductors constituting the multilayer coil component shown in Fig. 3. Note that Fig. 6 to Fig. 8 correspond to views of the laminate as viewed (perspectively) in the coil axis direction. The coil conductor shown in Fig. 4 has a rectangular repeating pattern, but the repeating pattern may also be a circular (see Fig. 6), elliptical (see Fig. 7), or track-shaped (see Fig. 8) coil conductor. A track-shaped coil conductor is a rectangle with a pair of opposing sides each bulging out into a semicircular shape. In addition, when the coil conductor has a shape with a longitudinal direction and a lateral direction, such as a rectangle, elliptical, or track shape, it is preferable that each coil conductor be arranged so that the longitudinal direction is parallel to the height direction. Furthermore, the repeating shape of the coil conductor may be a 1 / 2 turn shape instead of a 3 / 4 turn shape.

[0055] Fig. 9 is a plan view schematically showing the repeated shape of the coil conductors that make up the multilayer coil component shown in Fig. 3. Fig. 9 corresponds to a view of the laminate as seen (perspectively) in the coil axis direction. The repeating shape of the coil 30 (coil conductor 32) shown in FIG. 9 is rectangular, particularly rectangular.

[0056] The inner diameter area of ​​the coil 30 is larger than a predetermined area, specifically, 7500 μm 2This is as above. As a result, the impedance on the low frequency side increases, improving the low frequency characteristics and the transmission coefficient S21 in the low frequency band. The transmission coefficient S21 is calculated from the ratio of the power of the transmitted signal to the input signal. The transmission coefficient S21 for each frequency can be calculated using, for example, a network analyzer. The transmission coefficient S21 is basically a dimensionless quantity, but is usually expressed in dB units by taking the common logarithm.

[0057] From the viewpoint of improving low frequency characteristics, the inner diameter area of ​​the coil 30 is 10000 μm 2 It is preferable that the thickness is 13000 μm or more. 2 More preferably, it is 15,000 μm or more. 2 More preferably, it is equal to or greater than this. The upper limit of the inner diameter area of ​​the coil 30 is not particularly limited, but is preferably 25000 μm 2 Preferably, it is 20,000 μm or less. 2 More preferably, it is 18,000 μm or less. 2 It is more preferable that:

[0058] Here, the "inner diameter area of ​​the coil" means the area of ​​the region surrounded by the coil when the laminate is viewed in the coil axis direction. For example, when the shape of each coil conductor is rectangular, the inner diameter area of ​​the coil is calculated by taking the dimension of the laminate 10 in the width direction as B_W, the dimension of the laminate 10 in the height direction as B_T, and the width of the line portion 26 constituting the coil conductor 32 as W_T, as shown in FIG. C Assuming that the widthwise distance between the coil 30 and the first side surface 15 is the side gap G_W1, the widthwise distance between the coil 30 and the second side surface 16 is the side gap G_W2, the heightwise distance between the coil 30 and the first main surface 13 is the side gap G_T1, and the heightwise distance between the coil 30 and the second main surface 14 is the side gap G_T2, the side gap G_W1 can be calculated using the following formula. Coil inner diameter area = (B_W-G_W1-G_W2-W C ×2)×(B_T-G_T1-G_T2-W C ×2)

[0059] Furthermore, for example, when the shape of each coil conductor is circular, the inner diameter area of ​​the coil can be calculated using the following formula. Coil inner diameter area = (coil inner diameter ÷ 2) 2 ×π

[0060] Furthermore, for example, when the shape of each coil conductor is elliptical, the inner diameter area of ​​the coil can be calculated using the following formula. Coil inner diameter area = coil inner diameter in the major axis direction × coil inner diameter in the minor axis direction × π

[0061] Similarly, when each coil conductor has a track shape, the inner diameter area of ​​the coil can be calculated using mathematical techniques.

[0062] In this specification, the "inner diameter area of ​​the coil" refers to a value obtained by calculating the inner diameter area of ​​the coil at each of the three middle points when the laminate is divided into four equal parts in the length direction, or at the points where the coil conductor is located closest to each of the three middle points, and then taking the arithmetic mean.

[0063] Similarly, for other dimensions such as the width of the line portion, side gap, inner diameter of the coil, and thickness of the coil conductor, the relevant dimensions are calculated at each of the three middle points when the laminate is divided into four equal parts in the length direction, or at the points where the coil conductor is located closest to each of those three points, and the values ​​are obtained by taking the arithmetic mean.

[0064] The laminated coil component of the present invention preferably has a transmission coefficient S21 at 1 GHz of −1.0 dB or more, more preferably a transmission coefficient S21 at 1 GHz of −0.8 dB or more, even more preferably a transmission coefficient S21 at 1 GHz of −0.6 dB or more, and particularly preferably a transmission coefficient S21 at 1 GHz of −0.4 dB or more.

[0065] 9, when the laminate 10 is viewed in the direction of the coil axis A, the widthwise distance between the coil 30 and the first side surface 15 is defined as side gap G_W1, the widthwise distance between the coil 30 and the second side surface 16 is defined as side gap G_W2, the heightwise distance between the coil 30 and the first main surface 13 is defined as side gap G_T1, and the heightwise distance between the coil 30 and the second main surface 14 is defined as side gap G_T2. Preferably, the laminate 10 satisfies G_W1≧10 μm, G_W2≧10 μm, G_T1≧10 μm, and G_T2≧10 μm. If at least one of these side gaps is less than 10 μm, manufacturing problems, such as exposure of the coil conductor 32 from the laminate 10, may occur. G_W1, G_W2, G_T1 and G_T2 are each more preferably 15 μm or more and 30 μm or less, and further preferably 20 μm or more and 25 μm or less.

[0066] As shown in FIG. 9, the width W C is not particularly limited, but is preferably 15 μm or more and 30 μm or less, and more preferably 20 μm or more and 25 μm or less.

[0067] In the multilayer coil component of the present invention, the number of layers of the coil conductor is not particularly limited, but is preferably 10 to 50, more preferably 20 to 40, and even more preferably 25 to 35.

[0068] (Embodiment 2) FIG. 10 is a perspective view schematically illustrating an example of the multilayer coil component according to the second embodiment. 11A is a side view of the multilayer coil component shown in FIG. 10, FIG. 11B is a front view of the multilayer coil component shown in FIG. 10, and FIG. 11C is a bottom view of the multilayer coil component shown in FIG.

[0069] The multilayer coil component 1A shown in FIGS. 10, 11A, 11B, and 11C is compatible with miniaturization in the sense of achieving a low profile that satisfies height restrictions.

[0070] More specifically, if the dimensions of the laminate in the width direction (z direction), height direction (y direction), and length direction (x direction) are B_W (the length indicated by the double-headed arrow B_W in Figure 11C), B_T (the length indicated by the double-headed arrow B_T in Figure 11B), and B_L (the length indicated by the double-headed arrow B_L in Figure 11A), respectively, the laminate satisfies B_T≦200 μm, B_L≦400 μm, and 200 μm≦B_W.

[0071] The laminate preferably satisfies 210 μm≦B_W≦300 μm, and more preferably 260 μm≦B_W≦300 μm. The laminate also preferably satisfies 340 μm≦B_L≦380 μm, and more preferably 350 μm≦B_L≦370 μm. Furthermore, the laminate preferably satisfies 160 μm≦B_T≦200 μm, and more preferably 170 μm≦B_T≦190 μm.

[0072] Furthermore, if the dimensions of the laminated coil component in the width direction (z direction), height direction (y direction), and length direction (x direction) are W (the length indicated by the double-headed arrow W in FIG. 11C ), T (the length indicated by the double-headed arrow T in FIG. 11B ), and L (the length indicated by the double-headed arrow L in FIG. 11A ), respectively, the laminated coil component preferably satisfies 230 μm≦W≦320 μm, and more preferably satisfies 270 μm≦W≦310 μm. Furthermore, the laminated coil component preferably satisfies 380 μm≦L≦420 μm, and more preferably satisfies 390 μm≦L≦410 μm. Furthermore, the laminated coil component preferably satisfies 180 μm≦T≦220 μm, and more preferably satisfies 190 μm≦T≦210 μm.

[0073] In this embodiment, as in embodiment 1, any one of the first main surface 13, the second main surface 14, the first side surface 15, and the second side surface 16 of the laminate 10 can be the mounting surface, but the first main surface 13 is used as the mounting surface.

[0074] FIG. 12 is a cross-sectional view schematically illustrating an example of the multilayer coil component according to the second embodiment, and FIG. 13 is an exploded plan view schematically illustrating the state of insulating layers constituting the multilayer coil component shown in FIG. 12. 12 is a schematic diagram showing the insulating layers, coil conductors, connecting conductors, and the stacking direction of the laminate, and does not strictly represent the actual shapes, connections, etc. For example, the coil conductors are connected through via conductors.

[0075] As shown in FIGS. 12 and 13 , similar to the laminated coil component 1 of the first embodiment, the laminated coil component 1A includes a laminate 10 incorporating a coil 30 formed by electrically connecting a plurality of coil conductors 32 stacked together with insulating layers 31, and a first external electrode 21 and a second external electrode 22 electrically connected to the coil 30.

[0076] Also in the multilayer coil component 1A, similarly to the multilayer coil component 1 of the first embodiment, the inner diameter area of ​​the coil 30 is larger than a predetermined area, and therefore the transmission coefficient S21 in the low frequency band can be improved. That is, the inner diameter area of ​​the coil 30 is 7500 μm 2 More than 10000μm 2 It is preferable that the thickness is 13000 μm or more. 2 More preferably, it is 15,000 μm or more. 2 More preferably, it is equal to or greater than this. The inner diameter area of ​​the coil 30 is 25000 μm 2 Preferably, it is 20,000 μm or less. 2 More preferably, it is 18,000 μm or less. 2 It is more preferable that:

[0077] In this embodiment, the shape of each coil conductor 32 when viewed in a plane from the stacking direction is not particularly limited, but if the shape of the coil conductor 32 has a longitudinal direction and a lateral direction, such as a rectangular, elliptical, or track-shaped shape, it is preferable that each coil conductor 32 is arranged so that the longitudinal direction is parallel to the width direction.

[0078] [Manufacturing method for multilayer coil components] An example of a method for manufacturing the laminated coil component of the present invention will be described.

[0079] First, ceramic green sheets that will later become insulating layers are prepared. For example, an organic binder such as polyvinyl butyral resin, an organic solvent such as ethanol or toluene, a dispersant, etc. are added to a ferrite material and kneaded to form a slurry. Then, ceramic green sheets with a thickness of approximately 10 to 25 μm are prepared by a method such as a doctor blade method.

[0080] The ferrite material can be produced, for example, by the following method: First, oxide raw materials of iron, nickel, zinc, and copper are mixed and calcined at 800°C for 1 hour. The calcined material is then pulverized in a ball mill and dried to produce a Ni-Zn-Cu ferrite material (mixed oxide powder) with an average particle size of approximately 2µm.

[0081] When a ceramic green sheet is produced using a ferrite material, in order to obtain high inductance, the composition of the ferrite material is preferably Fe2O3: 40 mol% to 49.5 mol% inclusive, ZnO: 5 mol% to 35 mol% inclusive, CuO: 4 mol% to 12 mol% inclusive, and the remainder: NiO and trace amounts of additives (including unavoidable impurities).

[0082] As the material for the ceramic green sheets, in addition to the magnetic materials such as the ferrite materials mentioned above, for example, glass ceramic materials, non-magnetic materials such as willemite, and mixed materials of magnetic and non-magnetic materials may be used.

[0083] Next, conductor patterns that will later become coil conductors and via conductors are formed on the ceramic green sheet. For example, first, via holes are formed by laser processing the ceramic green sheet. Then, a conductive paste such as silver paste is filled into the via holes to form conductor patterns for the via conductors. Furthermore, a conductor pattern for the coil conductor is printed on the main surface of the ceramic green sheet using a conductive paste such as silver paste by a method such as screen printing. As the conductor pattern for the coil conductor, for example, a conductor pattern equivalent to the coil conductor shown in FIGS. 4 and 5 is printed. At this time, the shape of the conductor pattern for the coil conductor is set so that the inner diameter area of ​​the obtained coil is 7500 μm 2 The shape should be such that the above is achieved.

[0084] Thereafter, the ceramic green sheet is dried to obtain a coil sheet having a configuration in which conductor patterns for coil conductors and conductor patterns for via conductors are formed on the ceramic green sheet, and in the coil sheet, the conductor patterns for coil conductors and the conductor patterns for via conductors are connected to each other.

[0085] In addition to the coil sheet, a via sheet is also prepared, which has a configuration in which a conductor pattern for a via conductor is formed on a ceramic green sheet. The conductor pattern for a via conductor of the via sheet is a conductor pattern that will later become a via conductor that constitutes a connecting conductor.

[0086] Next, the coil sheets are stacked in a predetermined order so that after singulation and firing, a coil having a coil axis parallel to the mounting surface is formed inside the laminate. Furthermore, via sheets are laminated above and below the laminate of coil sheets.

[0087] Next, the laminate of the coil sheet and the via sheet is thermocompression bonded to obtain a compressed body, which is then cut into a predetermined chip size to obtain individual chips. The individual chips may be subjected to barrel polishing, for example, to round the corners and ridges.

[0088] Next, the individual chips are subjected to a binder removal process and firing at a predetermined temperature and time to form a laminate (fired body) with a built-in coil. At this time, the conductor patterns for the coil conductors and the conductor patterns for the via conductors become coil conductors and via conductors, respectively, after firing. The coil is formed by connecting the coil conductors to each other via conductors. Furthermore, the stacking direction of the laminate and the coil axis direction of the coil are parallel to the mounting surface.

[0089] Next, the laminate is vertically immersed in a layer of conductive paste such as silver paste stretched to a predetermined thickness and baked to form an underlying electrode layer for the external electrodes on five surfaces of the laminate (end surfaces, both main surfaces, and both end surfaces). In addition, by immersing the laminate at an angle in a layer of conductive paste such as silver paste stretched to a predetermined thickness and baking it, it is possible to form a base electrode layer for the external electrode on the four surfaces (main surface, end surface, and both side surfaces) of the laminate.

[0090] Next, a nickel coating and a tin coating having predetermined thicknesses are formed in this order on the base electrode layer by plating, thereby forming the external electrodes.

[0091] In this manner, the multilayer coil component of the present invention is manufactured. [Example]

[0092] EXAMPLES Hereinafter, examples will be given that more specifically disclose the multilayer coil component of the present invention, but the present invention is not limited to these examples.

[0093] [Sample preparation] (Sample 1) (1) A ferrite material (calcined powder) having a predetermined composition and a glass ceramic material having a predetermined composition were prepared.

[0094] (2) The above materials were added to a pot mill along with an organic binder (polyvinyl butyral resin) and an organic solvent (ethanol and toluene) along with PSZ balls, and thoroughly mixed and ground in a wet manner to produce a magnetic slurry containing non-magnetic material.

[0095] (3) The magnetic slurry was formed into a sheet by a doctor blade method, and then punched into rectangular shapes to produce a plurality of ceramic green sheets.

[0096] (4) A conductive paste for the internal conductor containing Ag powder and an organic vehicle was prepared.

[0097] (5) Fabricating a via sheet Via holes were formed by irradiating a predetermined portion of the ceramic green sheet with a laser, and conductive paste was filled into the via holes to form via conductors. The conductive paste was then screen-printed in a circular pattern around the via conductors to form lands.

[0098] (6) Coil sheet fabrication Via holes were formed in predetermined locations on the ceramic green sheets and filled with conductive paste to form via conductors, after which a coil conductor consisting of a land portion and a line portion was printed to obtain a coil sheet.

[0099] (7) These sheets were stacked in the order shown in Figures 4 and 5 so that the number of layers of the coil conductor was 28, and then heated and pressed, and cut into individual pieces with a dicer to produce a laminated molded body.

[0100] (8) The laminated compact was placed in a firing furnace, and subjected to a binder removal treatment at a temperature of 500°C in an air atmosphere, and then fired at a temperature of 900°C to produce a laminated body (fired). The dimensions of 30 pieces of the resulting laminate were measured using a micrometer, and the average values ​​were B_L=360μm, B_W=180μm, and B_T=280μm.

[0101] (9) A conductive paste for external electrodes containing Ag powder and glass frit was poured into a coating film forming tank to form a coating film of a predetermined thickness. The portions of the laminate where the external electrodes were to be formed were immersed in this coating film.

[0102] (10) After immersion, the substrate electrodes for the external electrodes were formed by baking at a temperature of about 800°C.

[0103] (11) An Ni film and an Sn film were sequentially formed on the base electrode by electrolytic plating to form an external electrode. As a result of the above, a multilayer coil component (sample 1) was produced having external electrodes with the shapes shown in Figures 1, 2A, 2B, and 2C, and an internal structure of the laminate as shown in Figures 3, 4, and 5. The dimensions of 30 of the resulting laminated coil components were measured using a micrometer, and the average values ​​were found to be L=400 μm, W=200 μm, and T=300 μm.

[0104] In sample 1, the number of turns of the coil is 21, the number of layers of the coil conductor is 28, and the width W of the line portion constituting the coil conductor is C was 26 μm, and the thickness of the coil conductor was 5 μm. The side gaps G_W1 and G_W2 were 22 μm, and the side gaps G_T1 and G_T2 were 92 μm. Furthermore, the distance between adjacent coil conductors in the lamination direction (hereinafter referred to as the inter-electrode distance) was 5 μm, the coil length was 275 μm, the inner diameter R_W in the coil width direction was 84 μm, the inner diameter R_T in the coil height direction was 94 μm, the inner diameter ratio of the coil was 1.12, and the outer layer thickness was 40 μm. The inner diameter area of ​​the coil was 7896 μm. 2 It was decided.

[0105] The coil length is calculated using the following formula: Coil length = number of layers of coil conductor × thickness of coil conductor + (number of layers of coil conductor - 1) × distance between electrodes

[0106] The coil inner diameter ratio is calculated using the following formula. Coil inner diameter ratio = Coil inner diameter in the height direction R_T ÷ Coil inner diameter in the width direction R_W

[0107] The outer layer thickness is a length calculated from the following formula. Outer layer thickness = (lengthwise dimension of element body B_L - coil length) ÷ 2

[0108] (Samples 2 to 4) Multilayer coil components (samples 2 to 4) were fabricated in the same manner as sample 1, except that the various parameters were changed as shown in Table 1.

[0109] [Table 1]

[0110] (Samples 5-7) Multilayer coil components (samples 5 to 7) were fabricated in the same manner as sample 1, except that the various parameters were changed as shown in Table 2.

[0111] [Table 2]

[0112] (Measurement of transmission coefficient S21) FIG. 14 is a diagram showing a schematic diagram of a method for measuring the transmission coefficient S21. 14, a sample (the multilayer coil component 1) was soldered to a measuring jig 60 provided with a signal path 61 and a ground conductor 62. The first external electrode 21 of the multilayer coil component 1 was connected to the signal path 61, and the second external electrode 22 was connected to the ground conductor 62.

[0113] The power of the input signal to the sample and the transmitted signal was determined using a network analyzer 63, and the transmission coefficient S21 was measured by changing the frequency. One end and the other end of the signal path 61 were connected to the network analyzer 63. The measurement results are shown in Figures 15 and 16. Figure 15 is a graph showing the transmission coefficient S21 of samples 1 to 4. Figure 16 is a graph showing the transmission coefficient S21 of samples 4 to 7. Note that the closer the transmission coefficient S21 is to 0 dB, the lower the loss. Figure 17 is a graph showing the relationship between the transmission coefficient S21 at 1 GHz and the inner diameter area of ​​the coil for each sample.

[0114] 15 to 17, it can be seen that there is a strong correlation between the transmission coefficient S21 at 1 GHz and the inner diameter area of ​​the coil. Furthermore, in samples 1 to 4, 6, and 7, which have a larger inner diameter area of ​​the coil by increasing the height while keeping the mounting area small, the transmission coefficient S21 at 1 GHz is improved compared to sample 5, which also has a small dimension in the height direction, and it was found that they have excellent low-frequency characteristics. Specifically, when the inner diameter area of ​​the coil is increased to 7500 μm 2 By setting the coil inner diameter to 10000 μm or more, the transmission coefficient S21 at 1 GHz can be set to -1.0 dB or more. 2 By setting the coil inner diameter to 13000 μm or more, the transmission coefficient S21 at 1 GHz can be set to -0.8 dB or more. 2 By setting the thickness to 15000μm or more, the transmission coefficient S21 at 1GHz can be set to -0.6dB or more, and the inner diameter area of ​​the coil can be set to 15000μm 2 It was found that by setting the above, the transmission coefficient S21 at 1 GHz can be set to -0.4 dB or more.

[0115] The present specification discloses the following:

[0116] <1> a laminated body formed by laminating a plurality of insulating layers in the length direction and having a coil built therein; 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 layers in the longitudinal direction, the laminate has a first end face and a second end face opposing each other in the length direction, a first main surface and a second main surface opposing each other in a height direction perpendicular to the length direction, and a first side surface and a second side surface opposing each other in a width direction perpendicular to the length direction and the height direction, a stacking direction of the laminate and a coil axis direction of the coil are parallel to the first main surface, the first main surface is a mounting surface, The dimensions of the laminate in the width direction, the height direction, and the length direction are defined as B_W, B_T, and B_L, respectively. the laminate satisfies B_W≦200 μm, B_L≦400 μm and 200 μm≦B_T, or B_T≦200 μm, B_L≦400 μm and 200 μm≦B_W, The inner diameter area of ​​the coil is 7500 μm 2 A multilayer coil component characterized by the above.

[0117] <2> The inner diameter area of ​​the coil is 10000 μm 2 That's all. <1> The multilayer coil component according to claim 1.

[0118] <3> The inner diameter area of ​​the coil is 13000 μm 2 That's all. <2> The multilayer coil component according to claim 1.

[0119] <4> The inner diameter area of ​​the coil is 15000 μm 2 That's all. <3> The multilayer coil component according to claim 1.

[0120] <5> the laminate is made of a mixed material of a ferrite material and a non-magnetic material having a dielectric constant lower than that of the ferrite material; <1> ~ <4> 10. The multilayer coil component according to claim 9, wherein the first and second layers are laminated.

[0121] <6> The distance between the coil and the first side surface in the width direction is defined as a side gap G_W1, the distance between the coil and the second side surface in the width direction is defined as a side gap G_W2, the distance between the coil and the first main surface in the height direction is defined as a side gap G_T1, and the distance between the coil and the second main surface in the height direction is defined as a side gap G_T2, The laminate satisfies G_W1≧10 μm, G_W2≧10 μm, G_T1≧10 μm, and G_T2≧10 μm, <1> ~ <5> 10. The multilayer coil component according to claim 9, wherein the first and second layers are laminated.

[0122] <7> When the plurality of coil conductors are seen through and stacked from the stacking direction, the shape is rectangular. <1> ~ <6> 10. The multilayer coil component according to claim 9, wherein the first and second layers are laminated.

[0123] <8> The number of turns of the coil is 10 or more. <1> ~ <7> 10. The multilayer coil component according to claim 9, wherein the first and second layers are laminated. [Explanation of symbols]

[0124] 1. 1A multilayer coil components 10 Laminate 11 first end face 12 Second end face 13 First principal surface 14 Second main surface 15 First Aspect 16 The Second Aspect 21 First external electrode 22 second external electrode 30 coils 31, 31a, 31b, 31c, 31d, 35a, 35a1, 35a2, 35a3, 35a4, 35b, 35b1, 35b2, 35b3, 35b4 insulating layers 32, 32a, 32b, 32c, 32d Coil conductors 33a, 33b, 33c, 33d, 33p, 33q via conductors 36a, 36b, 36c, 36d line section 37a, 37b, 37c, 37d Land section 41 First connecting conductor 42 Second connecting conductor 60 Measuring Jig 61 Signal Path 62 Ground conductor 63 Network Analyzer A Coil axis direction B_W Dimension of the laminate in the width direction B_T Dimension of stack in height direction B_L Dimension of the laminate in the length direction W: Dimension of the multilayer coil component in the width direction T Height dimension of multilayer coil component L is the lengthwise dimension of the multilayer coil component W C Line width G_W1: Distance between the coil and the first side surface in the width direction G_W2: Width distance between the coil and the second side surface G_T1: Distance between the coil and the first main surface in the width direction G_T2: The distance between the coil and the second main surface in the width direction

Claims

1. a laminated body formed by laminating a plurality of insulating layers in the length direction and having a coil built therein; 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 layers in the longitudinal direction, the laminate has a first end face and a second end face opposing each other in the length direction, a first main surface and a second main surface opposing each other in a height direction perpendicular to the length direction, and a first side surface and a second side surface opposing each other in a width direction perpendicular to the length direction and the height direction, a stacking direction of the laminate and a coil axis direction of the coil are parallel to the first main surface, the first main surface is a mounting surface, The dimensions of the laminate in the width direction, the height direction, and the length direction are defined as B_W, B_T, and B_L, respectively. the laminate satisfies B_W≦200 μm, B_L≦400 μm, and 200 μm≦B_T, or B_T≦200 μm, B_L≦400 μm, and 200 μm≦B_W, The inner diameter area of ​​the coil is 7500 μm ２ A multilayer coil component characterized by the above.

2. The inner diameter area of ​​the coil is 10,000 μm ２ The laminated coil component according to claim 1 .

3. The inner diameter area of ​​the coil is 13000 μm ２ The laminated coil component according to claim 2 .

4. The inner diameter area of ​​the coil is 15000 μm ２ The laminated coil component according to claim 3 .

5. 5. The multilayer coil component according to claim 1, wherein the laminate is made of a mixed material of a ferrite material and a non-magnetic material having a dielectric constant lower than that of the ferrite material.

6. A distance in the width direction between the coil and the first side surface is defined as a side gap G_W1, a distance in the width direction between the coil and the second side surface is defined as a side gap G_W2, a distance in the height direction between the coil and the first main surface is defined as a side gap G_T1, and a distance in the height direction between the coil and the second main surface is defined as a side gap G_T2, 5. The multilayer coil component according to claim 1, wherein the laminate satisfies G_W1≧10 μm, G_W2≧10 μm, G_T1≧10 μm, and G_T2≧10 μm.

7. 5. The multilayer coil component according to claim 1, wherein the shape of the plurality of coil conductors when viewed in a see-through manner from the stacking direction is rectangular.

8. 5. The multilayer coil component according to claim 1, wherein the number of turns of the coil is 10 or more.

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