Inductor element

Abstract

This inductor element comprises a first linear conductor and a second linear conductor. The first linear conductor has a first surface and a second surface orthogonal to the thickness direction and having a predetermined width and extends in a predetermined shape. The second linear conductor has a third surface and a fourth surface orthogonal to the thickness direction and extends in a predetermined shape. The first linear conductor and the second linear conductor are stacked in a state in which the second surface and the third surface face each other. The first linear conductor has a first recessed portion on the second surface, said first recessed portion being recessed at a position excluding both ends in the width direction.

Description

Inductor element

[0001] The present invention relates to an inductor element configured using a plurality of layers of conductor patterns.

[0002] Patent Document 1 describes an inductor including a first conductor pattern and a second conductor pattern stacked with an insulating film interposed therebetween.

[0003] When viewed in the stacking direction (in a plan view), the first conductor pattern and the second conductor pattern are arranged in a state where at least a part thereof in the width direction does not overlap.

[0004] International Publication No. 2022 / 215665

[0005] However, in the inductor disclosed in Patent Document 1, although parasitic capacitance is reduced, mutual inductance cannot be increased. Therefore, in the inductor of Patent Document 1, the inductance can only be increased by increasing the conductor length. Accordingly, in order to increase the inductance of the passive component of Patent Document 1, the passive component itself has to be enlarged, and the conductor length becomes longer, so that a high Q value cannot be achieved.

[0006] Accordingly, an object of the present invention is to provide an inductor element that achieves high inductance and a high Q value, and suppresses an increase in element area while achieving high inductance.

[0007] An inductor element according to an embodiment of the present invention includes a first linear conductor and a second linear conductor. The first linear conductor is orthogonal to the thickness direction, has a first surface and a second surface each having a predetermined width, and extends in a predetermined shape. The second linear conductor has a third surface and a fourth surface orthogonal to the thickness direction, and extends in a predetermined shape. The first linear conductor and the second linear conductor are stacked in a state where the second surface and the third surface face each other. The first linear conductor has, on the second surface thereof, a first recess recessed at a position excluding both ends in the width direction.

[0008] In this configuration, capacitive coupling and mutual inductive coupling can be appropriately adjusted without changing the distance between the first and second linear conductors in the stacking direction, nor without shifting the first and second linear conductors in the lateral direction perpendicular to the stacking direction. This makes it possible to suppress capacitive coupling and achieve a high Q value while suppressing area expansion and maintaining high inductance.

[0009] According to this invention, it is possible to realize an inductor element that achieves high inductance and a high Q value, while suppressing an increase in element area while achieving high inductance.

[0010] Figure 1 is a side cross-sectional view showing an example of the configuration of an inductor element according to the first embodiment. Figures 2(A) and 2(B) are enlarged views of the arrangement of the plurality of linear conductors according to the first embodiment. Figure 3 is a perspective view of the plurality of linear conductors according to the first embodiment. Figure 4 is a plan view (two-view drawing) of the plurality of linear conductors according to the first embodiment. Figure 5 is a plan view (two-view drawing) of the plurality of linear conductors according to the first embodiment. Figure 6(A) is a graph showing an example of the frequency characteristics of the Q value of the inductor element, and Figure 6(B) is a graph showing an example of the frequency characteristics of the impedance of the inductor element. Figure 7(A) is a diagram showing an example of the current distribution of the inductor element according to the first embodiment, Figure 7(B) is a diagram showing an example of the current distribution of the inductor element of Comparative Example 1, and Figure 7(C) is a diagram showing an example of the current distribution of the inductor element of Comparative Example 2. Figures 8(A), 8(B), 8(C), 8(D), 8(E), 8(F), and 8(G) show the state at each step in the first manufacturing method of the inductor element according to the first embodiment. Figures 9(A), 9(B), and 9(C) show the state at each step in the second manufacturing method of the inductor element according to the first embodiment. Figures 10(A) and 10(B) are cross-sectional views showing the configuration of the inductor element according to the second embodiment. Figure 11 is a cross-sectional view showing the configuration of the inductor element according to the third embodiment. Figures 12(A), 12(B), 12(C), 12(D), 12(E), 12(F), 12(G), 12(H), and 12(I) show other examples of linear conductor shapes. Figure 13 is a perspective view showing other examples of shapes of a plurality of linear conductors constituting an inductor element.

[0011] [First Embodiment] An inductor element according to the first embodiment of the present invention will be described with reference to the figures. Figure 1 is a side cross-sectional view showing an example of the configuration of the inductor element according to the first embodiment. Figures 2(A) and 2(B) are enlarged views of the arrangement of the plurality of linear conductors according to the first embodiment. Figure 3 is a perspective view of the plurality of linear conductors according to the first embodiment. Figures 4 and 5 are plan views (two-view views) of the plurality of linear conductors according to the first embodiment.

[0012] As shown in Figures 1, 2(A), 2(B), 3, 4, and 5, the inductor element 10 comprises a base substrate 20, an insulating layer 30, a linear conductor 41, and a linear conductor 42.

[0013] In this embodiment, for example, linear conductor 41 corresponds to the "first linear conductor" and linear conductor 42 corresponds to the "second linear conductor". Note that this relationship may be reversed. That is, linear conductor 41 corresponds to the "second linear conductor" and linear conductor 42 corresponds to the "first linear conductor".

[0014] The base substrate 20 is constructed using, for example, a Si substrate. However, the base substrate 20 can also be constructed using a ceramic substrate, a glass substrate, a glass epoxy substrate, or other semiconductor substrates.

[0015] An insulating layer 30 of a predetermined thickness is placed on the surface of the base substrate 20. The insulating layer 30 is made of, for example, polyimide, epoxy resin, PBO, etc.

[0016] The linear conductors 41 and 42 are arranged inside the insulating layer 30. The linear conductors 41 and 42 are made of, for example, metal. In this case, it is preferable that the linear conductors 41 and 42 are made of metal that can be easily formed by, for example, plating.

[0017] The linear conductors 41 and 42 are stacked in a manner that they are aligned sequentially along the thickness direction of the insulating layer 30. The direction in which the linear conductors 41 and 42 are aligned corresponds to the stacking direction.

[0018] The linear conductors 41 and 42 are arranged in the order of linear conductor 41, then linear conductor 42, from the base material 20 side.

[0019] As shown in Figure 3, the linear conductors 41 and 42 are wound in a spiral shape. In Figure 3, the linear conductors 41 and 42 are shown as a rectangular frame with a portion cut out, but they may also be circular or polygonal in shape other than a rectangle. The linear conductors 41 and 42 overlap and run parallel to each other in the stacking direction over approximately their entire length in the direction of extension.

[0020] The linear conductor 41 has an end E11 at one end in the direction of extension and an end E12 at the other end in the direction of extension. The linear conductor 42 has an end E21 at one end in the direction of extension and an end E22 at the other end in the direction of extension. Ends E12 and E21 are positioned to overlap when viewed in the stacking direction. Ends E12 and E21 are connected using a via conductor VIA (see Figure 3) formed in the insulating layer 30. With this configuration, the linear conductor 41, the linear conductor 42, and the via conductor VIA realize a helical inductor.

[0021] The end E11 of the linear conductor 41 is connected to the first external connection terminal via a via conductor (not shown) that penetrates the insulating layer 30 in the thickness direction. The end E22 of the linear conductor 42 is connected to the second external connection terminal via a via conductor (not shown) that penetrates the insulating layer 30 in the thickness direction.

[0022] The linear conductor 41 has a width W41. The linear conductor 41 comprises a main body 411, a projection 412, and a projection 413. The linear conductor 41 has a side surface FS412 at one end in the width W41 direction. The linear conductor 41 has a side surface FS413 at the other end in the width W41 direction.

[0023] The main body 411 is composed of a flat plate having a width W41 and a thickness D411. The main body 411 has a surface F411. Surface F411 corresponds to the "first surface".

[0024] The protrusions 412 and 413 protrude from the surface of the main body 411 opposite to the surface F411 (the surface corresponding to the bottom surface F419 of the recess 419). The protrusions 412 and 413 have a thickness D419.

[0025] The projection 412 is located at one end of the main body 411 in the width direction W41 (the end on the side FS412 side). The projection 412 has a surface FV412 on the opposite side of surface F411. The projection 413 is located at the other end of the main body 411 in the width direction W41 (the end on the side FS413 side). The projection 413 has a surface FV413 on the opposite side of surface F411. The plane containing surfaces FV412 and FV413 corresponds to the "second surface". The widths of the projections 412 and 413 are less than half the width W41 of the main body 411.

[0026] As a result, the linear conductor 41 has recesses 419 that are recessed at positions other than both ends in the width direction W41. In other words, the linear conductor 41 has a recess 419 with a bottom surface F419 between the protrusions 412 and 413 in the width direction W41. The bottom surface F419 of the recess 419 is closer to surface F411 than the side surface FS412 of the protrusion 412 and the side surface FS413 of the protrusion 413. The recess 419 corresponds to the "first recess" in the first embodiment.

[0027] The recess 419 is continuous between the end E11 and the end E12 along the direction in which the linear conductor 41 extends (strictly speaking, except for the position where the via conductor VIA is formed).

[0028] The recess 419 has a width W419. The depth of the recess 419 is the same as the thickness D419 of the protrusions 412 and 413.

[0029] The linear conductor 42 has a width W42. The linear conductor 42 comprises a main body 421, a projection 422, and a projection 423. The linear conductor 42 has a side surface FS422 at one end in the width W42 direction. The linear conductor 42 has a side surface FS423 at the other end in the width W42 direction.

[0030] The main body 421 is composed of a flat plate having a width W42 and a thickness D421. The main body 421 has a surface F421. Surface F421 corresponds to the "fourth surface".

[0031] The protrusions 422 and 423 protrude from the surface of the main body 421 opposite to the surface F421 (the surface corresponding to the bottom surface F429 of the recess 429). The protrusions 422 and 423 have a thickness D429.

[0032] The projection 422 is located at one end of the main body 421 in the width direction W42 (the end on the side FS422 side). The projection 422 has a surface FV422 on the opposite side of surface F421. The projection 423 is located at the other end of the main body 421 in the width direction W42 (the end on the side FS423 side). The projection 423 has a surface FV423 on the opposite side of surface F421. The plane containing surfaces FV422 and FV423 corresponds to the "third surface". The widths of the projections 422 and 423 are less than half the width W42 of the main body 421.

[0033] As a result, the linear conductor 42 has recesses 429 that are recessed at positions other than both ends in the width direction W42. In other words, the linear conductor 42 has a recess 429 with a bottom surface F429 between the protrusions 422 and 423 in the width direction W42. The bottom surface F429 of the recess 429 is closer to surface F421 than the side surface FS422 of the protrusion 422 and the side surface FS423 of the protrusion 423. The recess 429 corresponds to the "second recess" in the first embodiment.

[0034] The recess 429 is continuous along the direction in which the linear conductor 42 extends between the end E21 and the end E22 (strictly speaking, except for the position where the via conductor VIA is formed).

[0035] The recess 429 has a width W429. The depth of the recess 429 is the same as the thickness D429 of the protrusions 422 and 423.

[0036] The width W41 of the linear conductor 41 and the width W42 of the linear conductor 42 are the same. The width W419 of the recess 419 and the width W429 of the recess 429 are the same. The depth of the recess 419 and the depth of the recess 429 are the same.

[0037] The width of protrusion 412 and the width of protrusion 413 are the same, and the width of protrusion 422 and the width of protrusion 423 are the same. Furthermore, the width of protrusion 412, the width of protrusion 413, the width of protrusion 422, and the width of protrusion 423 are the same.

[0038] Furthermore, these widths and depths can also be varied.

[0039] The linear conductor 41 and the linear conductor 42 are stacked with surfaces having recesses 419 (surfaces FV412 and FV413) and surfaces having recesses 429 (surfaces FV422 and FV423) facing each other. More specifically, surfaces FV412 and FV422 are adjacent to each other with a gap between them, and surfaces FV413 and FV423 are adjacent to each other with a gap between them. Furthermore, when viewed in the stacking direction, recesses 419 and recesses 429 overlap. In other words, the bottom surface F419 of recess 419 and the bottom surface F429 of recess 429 face each other.

[0040] By using this configuration, the inductor element 10 can obtain the following characteristics. Figure 6(A) is a graph showing an example of the frequency characteristics of the Q value of the inductor element, and Figure 6(B) is a graph showing an example of the frequency characteristics of the impedance of the inductor element. In Figures 6(A) and 6(B), the solid line shows the characteristics of the inductor element according to the first embodiment (the inductor element of the present invention), and the dashed line shows the characteristics of the inductor element of the comparative example. The inductor element of the comparative example is an inductor element using a linear conductor without recesses, that is, a linear conductor with a simple rectangular cross-section.

[0041] With the above configuration, the inductor elements 10 can be stacked to shorten the distance between adjacent linear conductors 41 and 42, while the recesses 419 and 429 reduce the facing area at the closest distance. This increases the coupling between linear conductors 41 and 42 while suppressing an undesirable increase in parasitic capacitance. Therefore, the inductance of the inductor elements 10 can be increased while suppressing parasitic capacitance.

[0042] As a result, as shown in Figure 6(A), the inductor element 10 can obtain a Q value equal to or higher than that of the comparative inductor element, even though the cross-sectional area of ​​the linear conductor is smaller than that of the comparative inductor element, as shown in Figures 7(A) and (B) later.

[0043] Further, the linear conductor 41 and the linear conductor 42 are respectively provided with a recess 419 and a recess 429, whereby the length of the outer circumference of the cross-section can be increased. Accordingly, the resistance component can be reduced for high-frequency signals in which current flows due to the skin effect. As a result, the inductor element 10 can further improve the Q factor. In an example of the frequency characteristic of the Q factor of the inductor element shown in FIG. 6(A), a remarkable improvement in the Q factor is observed at approximately 1.5 GHz or higher. That is, it shows that at a predetermined frequency or higher, the improvement in the Q factor due to the skin effect becomes significantly larger than the decrease in the Q factor caused by the increase in resistance accompanying the reduction in the cross-sectional area of the linear conductor.

[0044] Here, the skin depth related to this skin effect is generally 1 / (πfμσ) １／２ (where f is the frequency of the high-frequency signal, μ is the magnetic permeability of the conductor, and σ is the electrical conductivity of the conductor). Therefore, if the frequency is equal to or higher than the frequency at which this skin depth becomes shallower (smaller) than 1 / 2 of the conductor thickness, a remarkable improvement in the Q factor can be obtained. Here, the conductor thickness refers to the thickness of the thinnest portion of the conductor.

[0045] Furthermore, the following effects can be obtained by providing the linear conductor 41 with the recess 419 in the middle of the width direction and providing the linear conductor 42 with the recess 429 in the middle of the width direction.

[0046] FIG. 7(A) is a diagram showing an example of the current distribution of the inductor element according to the first embodiment, FIG. 7(B) is a diagram showing an example of the current distribution of the inductor element of Comparative Example 1, and FIG. 7(C) is a diagram showing an example of the current distribution of the inductor element of Comparative Example 2. In FIG. 7(A), FIG. 7(B), and FIG. 7(C), portions with high current density are indicated by hatching. Comparative Example 1 has a configuration without recesses (a set of linear conductor 41P0 and linear conductor 42P0), and Comparative Example 2 has a configuration in which the cross-sections of adjacent linear conductors are trapezoidal and the short sides are arranged adjacent to each other (a set of linear conductor 41P1 and linear conductor 42P1).

[0047] As shown in FIG. 7(A), in the configuration of the present invention in which a recess is provided in the middle of the width direction of the linear conductor, the area of the region with high current density is equivalent to that of the configuration without a recess (rectangular cross-section). Accordingly, the transmission loss of high-frequency signals can be suppressed.

[0048] On the other hand, as shown in FIG. 7C, in an inductor element having a trapezoidal cross-section, current concentrates at the acute corners of the linear conductor 41P1 and the linear conductor 42P1. This reduces the area of the region with high current density.

[0049] As described above, the inductor element 10 (having a configuration with a recess in the middle of the width direction of the linear conductor) can improve the Q value while suppressing transmission loss of high-frequency signals.

[0050] Furthermore, by providing the configuration of the inductor element 10, the impedance can be shifted to a higher frequency side compared to a configuration without the recess. Although not shown in FIG. 6B, when the interval between linear conductors is narrowed, a peak occurs at a higher frequency.

[0051] Therefore, by providing the recess, the peak of impedance can be shifted to the higher frequency side, so the change in resonance frequency caused by the change in the interval between adjacent linear conductors can be reduced. Accordingly, the inductor element 10 can suppress the decrease in Q value caused by the change in the interval between adjacent linear conductors, compared to a configuration without the recess.

[0052] It should be noted that the gap GAP between the linear conductor 41 and the linear conductor 42 is shorter than the shortest distance in the thickness direction (stacking direction) between the linear conductor 41 and the linear conductor 42 in a configuration in which the linear conductor 41 and the linear conductor 42 do not include the recess 419 and the recess 429. Even with such a configuration, parasitic capacitance can be suppressed by providing the recess 419 and the recess 429. Furthermore, by shortening the gap GAP between the linear conductor 41 and the linear conductor 42, the height of the inductor element 10 can be reduced.

[0053] (First Manufacturing Method of Linear Conductor 41 and Linear Conductor 42) FIGS. 8A, 8B, 8C, 8D, 8E, 8F, and 8G are diagrams showing states in respective steps of the first manufacturing method for the inductor element according to the first embodiment. In the first manufacturing method, the inductor element 10 is manufactured as follows.

[0054] As shown in Figure 8(A), an insulating layer 31 is formed on the surface of the base substrate 20. A recess 310 is formed on the surface of the insulating layer 31. A seed electrode 4110 is formed on the surface of the insulating layer 31 having the recess 310. A resist film 80 is formed on both ends of the recess 310 on the surface of the seed electrode 4110.

[0055] As shown in Figure 8(B), a plating film 4120 is formed on the portion of the seed electrode 4110 that is not covered by the resist film 80.

[0056] As shown in Figure 8(C), the resist film 80 is peeled off, and the portion of the seed electrode 4110 other than the portion covered by the plating film 4120 is peeled off by pattern etching or the like. This forms a linear conductor 41 consisting of the remaining seed electrode 4110 and the plating film 4120.

[0057] As shown in Figure 8(D), an insulating layer 32 is formed on the surface of the insulating layer 31 and on the surface of the linear conductor 41.

[0058] As shown in Figure 8(E), a recess 320 is formed on the surface of the insulating layer 32. A seed electrode 4210 is formed on the surface of the insulating layer 32 having the recess 320. A resist film 80 is formed on the surface of the seed electrode 4210 at a position on the edge side of the recess 320 in the width direction.

[0059] As shown in Figure 8(F), a plating film 4220 is formed on the portion of the seed electrode 4210 that is not covered by the resist film 80.

[0060] As shown in Figure 8(G), the resist film 80 is peeled off, and the portion of the seed electrode 4210 other than the portion covered by the plating film 4220 is peeled off by pattern etching or the like. This forms a linear conductor 42 consisting of the remaining seed electrode 4210 and the plating film 4220.

[0061] After this, the surface of the insulating layer 32 is covered with an insulating layer to form external connection electrodes, etc.

[0062] (Second manufacturing method for linear conductors 41 and 42) Figures 9(A), 9(B), and 9(C) show the state at each step in the second manufacturing method for the inductor element according to the first embodiment. In the second manufacturing method, the inductor element 10 is manufactured as follows. The following description will cover up to the formation step of the linear conductor 41, but the linear conductor 42 can be manufactured by the same method as the linear conductor 41.

[0063] As shown in Figure 9(A), an insulating layer 31 is formed on the surface of the base substrate 20. A recess 310 is formed on the surface of the insulating layer 31. A seed electrode 4110 is formed on the surface of the insulating layer 31 having the recess 310.

[0064] As shown in Figure 9(B), a plating film 4120 is formed on the seed electrode 4110.

[0065] As shown in Figure 9(C), the parts of the plated film 4120 and the seed electrode 4110 other than the recess 310 are ground. This forms a linear conductor 41 consisting of the seed electrode 4110 and the plated film 4120.

[0066] The insulating layer 32 and the linear conductor 42 are formed in the same manner as the method for forming the insulating layer 31 and the linear conductor 41.

[0067] [Second Embodiment] An inductor element according to a second embodiment of the present invention will be described with reference to the figures. Figures 10(A) and 10(B) are cross-sectional views showing the configuration of the inductor element according to the second embodiment. Figure 10(A) shows a two-layer configuration, and Figure 10(B) shows a three-layer configuration.

[0068] As shown in Figure 10(A), the inductor element 10A according to the second embodiment differs from the inductor element 10 according to the first embodiment in the orientation of the linear conductor 42. The other configurations of the inductor element 10A are the same as those of the inductor element 10, and a description of the similar parts will be omitted.

[0069] The linear conductor 41 is positioned so that the surface having the recess 419 faces the linear conductor 42.

[0070] The linear conductor 42 is positioned so that the side having the recess 429 faces away from the linear conductor 41. In other words, the recess 419 of the linear conductor 41 and the recess 429 of the linear conductor 42 open in the same direction in the stacking direction.

[0071] With this configuration, the inductor element 10A can achieve high inductance and a high Q value while suppressing the need for a large area.

[0072] Figure 10(B) shows an example of a linear conductor arranged in three layers. The inductor element 10AX comprises a linear conductor 41, a linear conductor 42, and a linear conductor 43. The linear conductor 43 has substantially the same configuration as the linear conductor 41 and has a recess 439.

[0073] The linear conductors 41, 42, and 43 are arranged in the order of linear conductor 41, linear conductor 42, and linear conductor 43 from the surface side of the base substrate 20.

[0074] The linear conductor 41 is positioned so that the surface having the recess 419 faces the linear conductor 42. The linear conductor 42 is positioned so that the surface having the recess 429 faces away from the linear conductor 41. The linear conductor 42 is positioned so that the surface having the recess 429 faces away from the linear conductor 41.

[0075] In other words, the recesses 419 of the linear conductor 41, 429 of the linear conductor 42, and 439 of the linear conductor 43 open in the same direction in the stacking direction.

[0076] With this configuration, the inductor element 10AX can achieve even higher inductance and a higher Q value while suppressing the need for a large area.

[0077] Thus, the inductor element may have three or more layers of linear conductors.

[0078] [Third Embodiment] An inductor element according to a third embodiment of the present invention will be described with reference to the figures. Figure 11 is a cross-sectional view showing the configuration of the inductor element according to the third embodiment.

[0079] As shown in Figure 11, the inductor element 10B according to the third embodiment differs from the inductor element 10 according to the first embodiment in the orientation of the linear conductor 41. The other configurations of the inductor element 10B are the same as those of the inductor element 10, and a description of the similar parts will be omitted.

[0080] The linear conductor 42 is positioned so that the surface having the recess 429 faces the linear conductor 41.

[0081] The linear conductor 41 is positioned such that the surface having the recess 419 faces away from the linear conductor 41 side. In other words, the recess 419 of the linear conductor 41 and the recess 429 of the linear conductor 42 open towards the same base material 20 side in the stacking direction.

[0082] With this configuration, the inductor element 10B can achieve high inductance and a high Q value while suppressing the need for a large area.

[0083] [Examples of concave shapes] Figures 12(A), 12(B), 12(C), 12(D), 12(E), 12(F), 12(G), 12(H), and 12(I) show other examples of shapes for a linear conductor. Figures 12(A), 12(B), 12(C), and 12(D) show other examples of shapes using the linear conductor 41 as an example, but these shape examples can also be applied to the linear conductor 42.

[0084] As shown in Figure 12(A), in the linear conductor 41X1, the cross-sectional shape of the projection 413 that forms the recess 419 is tapered.

[0085] As shown in Figure 12(B), even in the linear conductor 41X2, the cross-sectional shape of the projection 413 that forms the recess 419 is tapered, and furthermore, the shape from the bottom surface to the side wall surface of the recess 419 is smooth and arc-shaped.

[0086] As shown in Figure 12(C), in the linear conductor 41X3, the recess 419 is composed of multiple recesses.

[0087] As shown in Figure 12(D), the linear conductor 41X4 has a protrusion 4190 within the recess 419. Preferably, the protrusion 4190 is shaped so that it does not protrude from the recess 419.

[0088] As shown in Figure 12(E), in the linear conductor 41X5, the height of the protrusion 4190 is the same as the height of the projections 412 and 413.

[0089] As shown in Figure 12(F), in the linear conductor 41X6, the protruding portions 412X6 and 413X6 have curved surfaces (R-chamfered) on the beam portion (corner portion when viewed from the side) on the recessed portion 419 side.

[0090] As shown in Figure 12(G), in the linear conductor 41X7, the protrusion 413 is higher than the protrusion 412. In other words, the inner protrusion of the winding in the linear conductor 41X7 is higher than the outer protrusion.

[0091] As shown in Figure 12(H), the linear conductor 41X8 is composed of a main body 411 and a protruding portion 413, and has a recess 419X8. In other words, the linear conductor 41X8 has a protruding portion on the inside of the winding shape and no protruding portion on the outside.

[0092] As shown in Figure 12(I), the linear conductor 41X9 is composed of a main body 411X9 and a protruding portion 413X9, and has a recess 419X9. The main body 411X9 is thicker towards the protruding portion 413X9. In other words, the cross-sectional shape of the protruding portion 413X9 is tapered.

[0093] In Figures 12(A) to 12(I), the outer surface of the protruding portion 413 is perpendicular to the main body portion 411, but it may have some inclination with respect to the width direction of the main body portion 411 so that the macroscopic shape of the linear conductors 41X1 to 41X9 becomes dish-shaped.

[0094] These configurations can also produce the same effects as the inductor elements described above.

[0095] [Examples of Inductor Element Shapes] Figure 13 is a perspective view showing other examples of shapes of the multiple linear conductors that make up an inductor element.

[0096] The inductor element 10Y shown in Figure 13 comprises a linear conductor 41Y and a linear conductor 42Y. Each of the linear conductors 41Y and 42Y is constructed with a substantially double winding configuration.

[0097] The linear conductor 41Y has an inner circumference end E41I and an outer circumference end E41O. The linear conductor 41Y is wound clockwise from the outer circumference end E41O to the inner circumference end E41I.

[0098] The linear conductor 42Y has an inner circumference end E42I and an outer circumference end E42O. The linear conductor 42Y is wound clockwise from the inner circumference end E42I to the outer circumference end E42O.

[0099] The linear conductors 41Y and 42Y are stacked with their respective winding surfaces parallel. The linear conductors 41Y and 42Y face each other along approximately their entire length in the direction of extension.

[0100] The surface of the linear conductor 41Y facing the linear conductor 42Y has a recess 419. The surface of the linear conductor 42Y facing the linear conductor 41Y has a recess 429. The recesses 419 and 429 overlap when viewed in the stacking direction.

[0101] The inner circumference end E41I of the linear conductor 41Y and the inner circumference end E42I of the linear conductor 42Y are connected by via conductors (not shown). With this configuration, the inductor element 10Y forms a spiral-type inductor.

[0102] An inductor element 10Y having linear conductors 41Y and 42Y with such configurations has the same characteristics in the opposing portions of linear conductor 41Y and linear conductor 42Y as in the opposing portions of linear conductor 41 and linear conductor 42 of inductor element 10.

[0103] Furthermore, if the linear conductors 41Y and 42Y are not connected by via conductors, the inductor element 10Y can also be used as a functional element in which the linear conductors 41Y and 42Y run parallel to each other.

[0104] As a result, the inductor element 10Y, like the inductor element 10, can suppress the need for large area size while achieving high inductance and a high Q value.

[0105] Furthermore, the configurations of each embodiment described above, the derived configurations, and the various shape examples can be combined as appropriate.

[0106] 10, 10A, 10AX, 10B, 10Y: Inductor element 20: Base substrate 30, 31, 32: Insulator layer 41, 41X1, 41X2, 41X3, 41X4, 41X5, 41X6, 41X7, 41X8, 41X9, 41Y, 42, 42Y, 43, 41P0, 41P1, 42P0, 42P1: Linear conductor 80: Resist film 310, 320: Recess 411, 421, 411X9: Main body 412, 413, 422, 423, 412X6, 413X6, 413X9: Protrusion 419, 429, 439, 419X8, 419X9: Recess 4110, 4210: Seed electrode 4120, 4220: Plating film 4190: Protrusion D411, D419, D421, D429: Thickness E11, E12, E21, E22: Ends E41I, E42I: Inner circumference ends E41O, E42O: Outer circumference ends F411, F421, FV412, FV413, FV422, FV423: Surfaces F419, F429: Bottom surfaces FS412, FS413, FS422, FS423: Side surfaces VIA: Via conductor

Claims

1. An inductor element comprising: a first linear conductor having a first surface and a second surface of a predetermined width perpendicular to the thickness direction and extending in a predetermined shape on the surface perpendicular to the thickness direction; and a second linear conductor having a third surface and a fourth surface of a predetermined width perpendicular to the thickness direction and extending in a predetermined shape on the surface perpendicular to the thickness direction, wherein the first linear conductor and the second linear conductor are stacked with the second surface and the third surface facing each other, and the first linear conductor has a first recess on the second surface that is recessed at positions excluding both ends in the width direction.

2. The inductor element according to claim 1, wherein the second linear conductor has a second recess on the third surface that is recessed at positions other than both ends in the width direction.

3. The inductor element according to claim 1, wherein the second linear conductor has a second recess on the fourth surface that is recessed at positions other than both ends in the width direction.

4. The inductor element according to any one of claims 1 to 3, wherein the first linear conductor and the second linear conductor constitute a helical inductor.

5. The inductor element according to any one of claims 1 to 4, wherein the first linear conductor and the second linear conductor constitute a spiral inductor.

6. The inductor element according to any one of claims 1 to 5, wherein the thickness of the first linear conductor and the thickness of the second linear conductor are the same, and the shortest distance in the thickness direction between the first linear conductor and the second linear conductor is shorter than the shortest distance in the thickness direction between the first linear conductor and the second linear conductor in a configuration in which the first linear conductor does not have the first recess.

7. An inductor element according to any one of claims 1 to 5, comprising a semiconductor base substrate and an insulating layer formed on the base substrate, wherein the first linear conductor and the second linear conductor are stacked in a manner that they are sequentially aligned along the thickness direction of the insulating layer.

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