filter circuit

Abstract

Even if layer misalignment occurs, it suppresses changes in properties. [Solution] The filter circuit includes an inductor formed by connecting groups of wirings formed on multiple conductive layers of a substrate in series via vias, a first wiring having one end of the inductor from the wiring group, a third wiring formed on an adjacent conductive layer in a direction perpendicular to the main surface of the substrate of the conductive layer on which the first wiring is formed, and one end of which is electrically connected via via to a second wiring having the other end of the inductor from the wiring group, and a capacitor formed by overlapping these when viewed from a direction perpendicular to the main surface of the substrate.

Description

Technical Field

[0001] This disclosure relates to a filter circuit.

Background Art

[0002] The following Patent Document 1 describes an LC parallel resonance circuit configured using a conductor layer of a substrate.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the LC parallel resonance circuit described in Patent Document 1, consider a case where one conductor layer constituting one electrode of the capacitor and another conductor layer constituting the other electrode are formed so as to be displaced relative to each other along the plane direction of the substrate (hereinafter referred to as "layer displacement" in this disclosure).

[0005] When layer displacement occurs between one conductor layer constituting one electrode of the capacitor and another conductor layer constituting the other electrode of the capacitor, the area where the two electrodes overlap changes when viewed from the vertical direction of the substrate. If the area where one electrode and the other electrode of the capacitor overlap changes, the capacitance of the capacitor changes from the design value, and the characteristics of the LC parallel resonance circuit change from the design value. That is, in the LC parallel resonance circuit described in Patent Document 1, when layer displacement occurs, the characteristics change from the design value.

[0006] This disclosure has been made in view of the above, and an object thereof is to suppress the change in characteristics even when layer displacement occurs.

Means for Solving the Problems

[0007] A filter circuit according to one aspect of the present disclosure is a filter circuit formed on a substrate, and includes an inductor formed by connecting groups of wirings formed on each of a plurality of conductive layers of the substrate in series via vias; a first wiring having one end of the inductor among the wiring groups; and a third wiring formed on an adjacent conductive layer in a direction perpendicular to the main surface of the substrate of the conductive layer on which the first wiring is formed, with one end electrically connected via via to a second wiring having the other end of the inductor among the wiring groups; and a capacitor formed by overlapping these three wirings when viewed from a direction perpendicular to the main surface of the substrate.

[0008] A filter circuit according to one aspect of the present disclosure is a filter circuit formed on a substrate, and includes an inductor formed by connecting groups of wirings formed on a plurality of conductive layers of the substrate in series via vias, and a capacitor formed by overlapping, when viewed from a direction perpendicular to the main surface of the substrate, the first wiring having a circular shape and the tip of a first protrusion that protrudes inward from the first wiring, and the second wiring having the other end of the inductor, with the tip of a second protrusion that protrudes inward from the second wiring. [Effects of the Invention]

[0009] According to this disclosure, it is possible to suppress changes in properties even if layer misalignment occurs. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is an equivalent circuit diagram of the filter circuit of the first embodiment. [Figure 2] Figure 2 illustrates the laminated structure of the substrate on which the filter circuit of the first embodiment is formed. [Figure 3] Figure 3 is a perspective view of the filter circuit according to the first embodiment. [Figure 4] Figure 4 shows the wiring shape of each conductive layer in the filter circuit of the first embodiment. [Figure 5]Figure 5 is a diagram showing the first and second wiring of the filter circuit of the first embodiment superimposed on each other. [Figure 6] Figure 6 shows the circuit simulation results of the filter circuit according to the first embodiment. [Figure 7] Figure 7 illustrates the laminated structure of the substrate on which the filter circuit of the second embodiment is formed. [Figure 8] Figure 8 is a perspective view of the filter circuit according to the second embodiment. [Figure 9] Figure 9 shows the wiring shape of each conductive layer in the filter circuit of the second embodiment. [Figure 10] Figure 10 is a diagram showing the first and third wiring of the filter circuit of the second embodiment superimposed. [Modes for carrying out the invention]

[0011] The embodiments of this disclosure will be described in detail below with reference to the drawings. However, the present invention is not limited by these embodiments. Each embodiment is illustrative, and it goes without saying that partial substitution or combination of the configurations shown in different embodiments is possible. In the second and subsequent embodiments, descriptions of matters common to the first embodiment will be omitted, and only the differences will be described. In particular, similar effects and advantages due to similar configurations will not be mentioned sequentially for each embodiment.

[0012] <First Embodiment> (composition) Figure 1 is an equivalent circuit diagram of the filter circuit of the first embodiment.

[0013] The filter circuit 1 includes an inductor L1 and a capacitor C1 connected in parallel between the first terminal 1a and the second terminal 1b. In other words, the filter circuit 1 is an LC parallel circuit. The filter circuit 1 is formed on a substrate (for example, a printed wiring board (PWB)).

[0014] FIG. 2 is a diagram for explaining the stacked structure of a substrate on which a filter circuit according to the first embodiment is formed.

[0015] The substrate 10 includes from the first conductor layer 11 to the fourth conductor layer 14 and from the first dielectric layer 21 to the third dielectric layer 23.

[0016] The first dielectric layer 21 is formed between the first conductor layer 11 and the second conductor layer 12. The second dielectric layer 22 is formed between the second conductor layer 12 and the third conductor layer 13. The third dielectric layer 23 is formed between the third conductor layer 13 and the fourth conductor layer 14.

[0017] FIG. 3 is a perspective view of the filter circuit according to the first embodiment. In FIG. 3, only the conductor layers are shown, and the description of the dielectric layers is omitted.

[0018] The filter circuit 1 includes from the first wiring 31 to the fourth wiring 34. The first wiring 31 is formed on the first conductor layer 11 (see FIG. 2). The second wiring 32 is formed on the second conductor layer 12 (see FIG. 2). The third wiring 33 is formed on the third conductor layer 13 (see FIG. 2). The fourth wiring 34 is formed on the fourth conductor layer 14 (see FIG. 2).

[0019] The first wiring 31, the third wiring 33, and the fourth wiring 34 correspond to an example of the "wiring group" of the present disclosure. The first wiring 31 corresponds to an example of the "first wiring" of the present disclosure. The fourth wiring 34 corresponds to an example of the "second wiring" of the present disclosure. The second wiring 32 corresponds to an example of the "third wiring" of the present disclosure.

[0020] FIG. 4 is a diagram showing the shapes of the wirings of each conductor layer of the filter circuit according to the first embodiment.

[0021] Referring to FIGS. 3 and 4, one end of the first wiring 31 is the first terminal 1a (see FIG. 1). The first wiring 31 is wound clockwise in a plan view.

[0022] A planar view refers to viewing the substrate 10 from a direction perpendicular to its main surface (XY plane) (viewing the substrate 10 in the opposite direction to the Z axis).

[0023] The first wiring 31 has a first portion 31a, a second portion 31b, a third portion 31c, and a fourth portion 31d.

[0024] The first part 31a has one end as the first terminal 1a and extends in the X-axis direction. The second part 31b has one end connected to the other end of the first part 31a and extends in the opposite direction to the Y-axis direction. The third part 31c has one end connected to the other end of the second part 31b and extends in the opposite direction to the X-axis direction. The fourth part 31d has one end connected to the other end of the third part 31c and extends in the Y-axis direction.

[0025] The other end of the fourth section 31d is connected to the third wiring 33 via via 41.

[0026] One end of the second wiring 32 is connected to the fourth wiring 34 via a via 42. The via 42 is formed in a location that corresponds approximately to the center of the annular first wiring 31 when viewed from above. The second wiring 32 extends in the Y-axis direction.

[0027] The third wiring 33 has one end connected to via 41. When viewed from above, the third wiring 33 is wound clockwise.

[0028] The third wiring 33 has a first portion 33a, a second portion 33b, a third portion 33c, and a fourth portion 33d.

[0029] The first part 33a is connected at one end to via 41 and extends in the Y-axis direction. The second part 33b is connected at one end to the other end of the first part 33a and extends in the X-axis direction. The third part 33c is connected at one end to the other end of the second part 33b and extends in the opposite direction to the Y-axis direction. The fourth part 33d is connected at one end to the other end of the third part 33c and extends in the opposite direction to the X-axis direction.

[0030] The other end of the fourth section 33d is connected to the fourth wiring 34 via via 43.

[0031] The fourth wire 34 has one end connected to via 43. When viewed from above, the fourth wire 34 is wound clockwise.

[0032] The fourth wiring 34 has a first portion 34a, a second portion 34b, a third portion 34c, and a fourth portion 34d.

[0033] The first part 34a is connected at one end to via 43 and extends in the Y-axis direction. The second part 34b is connected at one end to the other end of the first part 34a and extends in the X-axis direction. The third part 34c is connected at one end to the other end of the second part 34b and extends in the opposite direction to the Y-axis direction. The fourth part 34d is connected at one end to the other end of the third part 34c and extends in the opposite direction to the X-axis direction.

[0034] The other end of the fourth section 34d is the second terminal 1b (see Figure 1).

[0035] Furthermore, the fourth wiring 34 has a fifth portion 34e extending in the Y-axis direction from the second terminal 1b. One end of the fifth portion 34e is connected to the second terminal 1b. The other end of the fifth portion 34e is connected to one end of the second wiring 32 via a via 42.

[0036] The first wiring 31, the third wiring 33, and the fourth wiring 34 are connected in series via vias 41 and 43 to form an inductor L1.

[0037] Figure 5 is a diagram showing the first and second wiring of the filter circuit of the first embodiment superimposed on each other.

[0038] The first portion 31a of the first wiring 31 and the second wiring 32 overlap in a plus sign shape when viewed from above.

[0039] One end of the first portion 31a of the first wiring 31 is connected to the first terminal 1a of the filter circuit 1. The second wiring 32 is connected to the second terminal 1b of the filter circuit 1 via via 42 and the fifth portion 34e of the fourth wiring 34. Therefore, the overlapping portion of the first portion 31a of the first wiring 31 and the second wiring 32 constitutes the capacitor C1 (see Figure 1).

[0040] (Circuit simulation) Figure 6 shows the circuit simulation results of the filter circuit of the first embodiment. In Figure 6, the horizontal axis represents frequency (GHz), and the vertical axis represents the pass-through characteristic (dB).

[0041] Line 101 shows the circuit simulation results of the filter circuit 1 of the first embodiment.

[0042] Line 102 shows the circuit simulation results for the first comparative example. The first comparative example is an inductor L1 obtained by removing capacitor C1 from filter circuit 1. That is, the first comparative example is an inductor L1 obtained by removing the second wiring 32, via 42, and the fifth portion 34e of the fourth wiring 34 from filter circuit 1, as shown in Figures 3 and 4.

[0043] Line 103 shows the circuit simulation results for the second comparative example. The second comparative example is a filter circuit 1 shown in Figure 1 implemented using a surface mount device (SMD).

[0044] As shown by lines 101 and 103, the filter circuit 1 of the first embodiment has pass characteristics similar to those of the second comparative example (filter circuit realized with surface mount devices).

[0045] As shown by lines 102 and 103, the first comparative example (inductor L1) has significantly different transmission characteristics from the second comparative example.

[0046] (effect) Referring to Figure 5, the first portion 31a of the first wiring 31 and the second wiring 32 overlap in a plus sign shape when viewed from above. Therefore, even if the first wiring 31 and the second wiring 32 are formed with a relative offset along the X-axis (i.e., they are layer-shifted relative to each other along the X-axis), the change in the overlapping area of ​​the first portion 31a of the first wiring 31 and the second wiring 32 when viewed from above is suppressed. In other words, the change in the capacitance of capacitor C1 is suppressed.

[0047] Therefore, even if the first wiring 31 and the second wiring 32 are formed with a relative offset along the X-axis, the filter circuit 1 can suppress changes in its transmission characteristics.

[0048] Furthermore, the first portion 31a of the first wiring 31 and the second wiring 32 overlap in a plus sign shape when viewed from above. Therefore, even if the first wiring 31 and the second wiring 32 are formed with a relative offset along the Y-axis (i.e., they are layer-shifted relative to each other along the Y-axis), the change in the overlapping area of ​​the first portion 31a of the first wiring 31 and the second wiring 32 when viewed from above is suppressed. In other words, the change in the capacitance of capacitor C1 is suppressed.

[0049] Therefore, even if the first wiring 31 and the second wiring 32 are formed with a relative offset along the Y-axis, the filter circuit 1 can suppress changes in its transmission characteristics.

[0050] Furthermore, even if the first wiring 31 and the second wiring 32 are formed offset relative to each other along the X-axis and offset relative to each other along the Y-axis, the change in the overlapping area of ​​the first portion 31a of the first wiring 31 and the second wiring 32 in a plan view is suppressed. In other words, the change in the capacitance of the capacitor C1 is suppressed.

[0051] Therefore, even if the first wiring 31 and the second wiring 32 are formed with a relative offset along the X-axis and a relative offset along the Y-axis, the filter circuit 1 can suppress changes in its transmission characteristics.

[0052] (First variation) In the examples shown in Figures 4 and 5, the first portion 31a of the first wiring and the second wiring 32 are shown overlapping in a plus sign shape, but the disclosure is not limited to this. By shortening the length of the second wiring 32 in the Y-axis direction, the first portion 31a of the first wiring and the second wiring 32 may overlap in a T-shape.

[0053] As a result, even if the first wiring 31 and the second wiring 32 are formed with a relative offset along the X-axis direction (i.e., they are layer-shifted relative to each other along the X-axis direction), changes in the overlapping area between the first portion 31a of the first wiring 31 and the second wiring 32 are suppressed. In other words, changes in the capacitance of capacitor C1 are suppressed.

[0054] Therefore, even if the first wiring 31 and the second wiring 32 are formed with a relative offset along the X-axis, the filter circuit 1 can suppress changes in its transmission characteristics.

[0055] (Second variation) In the examples shown in Figures 4 and 5, the angle between the first portion 31a of the first wiring 31 and the second wiring 32 is assumed to be approximately 90° in a plan view, but the disclosure is not limited to this. The angle between the first portion 31a of the first wiring 31 and the second wiring 32 may be approximately 45° or other angles in a plan view.

[0056] (Third variation) In the examples shown in Figures 4 and 5, the inductor L1 is assumed to be composed of three conductive layers: a first wiring 31, a third wiring 33, and a fourth wiring 34. However, the disclosure is not limited to this. The inductor L1 may also be composed of two or four or more conductive layers.

[0057] (Fourth variation) In the examples shown in Figures 4 and 5, the first wiring 31, the third wiring 33, and the fourth wiring 34 are rectangular in shape when viewed from above, but the disclosure is not limited thereto. The first wiring 31, the third wiring 33, and the fourth wiring 34 may be circular or have other shapes when viewed from above.

[0058] <Second Embodiment> (composition) The equivalent circuit diagram of the filter circuit 1A in the second embodiment is the same as the equivalent circuit diagram of the filter circuit 1 in the first embodiment (see Figure 1), so its illustration and description are omitted.

[0059] Figure 7 illustrates the laminated structure of the substrate on which the filter circuit of the second embodiment is formed.

[0060] The substrate 10A includes a first conductive layer 71 to a third conductive layer 73 and a first dielectric layer 81 to a second dielectric layer 82.

[0061] The first dielectric layer 81 is formed between the first conductive layer 71 and the second conductive layer 72. The second dielectric layer 82 is formed between the second conductive layer 72 and the third conductive layer 73.

[0062] Figure 8 is a perspective view of the filter circuit according to the second embodiment. In Figure 8, only the conductive layer is shown, and the dielectric layer is omitted.

[0063] The filter circuit 1A includes the first wiring 51 to the third wiring 53. The first wiring 51 is formed in the first conductive layer 71 (see Figure 7). The second wiring 52 is formed in the second conductive layer 72 (see Figure 7). The third wiring 53 is formed in the third conductive layer 73 (see Figure 7).

[0064] The first wiring 51 to the third wiring 53 correspond to an example of the “wiring group” in this disclosure. The first wiring 51 corresponds to an example of the “first wiring” in this disclosure. The third wiring 53 corresponds to an example of the “second wiring” in this disclosure.

[0065] Figure 9 shows the wiring shape of each conductive layer in the filter circuit of the second embodiment.

[0066] Referring to Figures 8 and 9, the first wiring 51 has one end connected to the first terminal 1a (see Figure 1). When viewed from above, the first wiring 51 is wound clockwise.

[0067] The first wiring 51 has a first portion 51a, a second portion 51b, a third portion 51c, and a fourth portion 51d.

[0068] The first part 51a has one end as the first terminal 1a and extends in the X-axis direction. The second part 51b has one end connected to the other end of the first part 51a and extends in the opposite direction to the Y-axis direction. The third part 51c has one end connected to the other end of the second part 51b and extends in the opposite direction to the X-axis direction. The fourth part 51d has one end connected to the other end of the third part 51c and extends in the Y-axis direction.

[0069] The other end of the fourth section 51d is connected to the second wiring 52 via via 61.

[0070] Furthermore, the first wiring 51 has a fifth portion 51e extending from the first portion 51a in the opposite direction to the Y-axis. One end of the fifth portion 51e is connected to the first portion 51a. The other end of the fifth portion 51e is located approximately in the center of the first wiring 51 when viewed from above. The other end of the fifth portion 51e has a circular shape when viewed from above.

[0071] The fifth portion 51e of the first wiring 51 corresponds to an example of the “first protrusion” of this disclosure.

[0072] The second wiring 52 has one end connected to via 61. When viewed from above, the second wiring 52 is wound clockwise.

[0073] The second wiring 52 has a first portion 52a, a second portion 52b, a third portion 52c, and a fourth portion 52d.

[0074] The first part 52a is connected at one end to via 61 and extends in the Y-axis direction. The second part 52b is connected at one end to the other end of the first part 52a and extends in the X-axis direction. The third part 52c is connected at one end to the other end of the second part 52b and extends in the opposite direction to the Y-axis direction. The fourth part 52d is connected at one end to the other end of the third part 52c and extends in the opposite direction to the X-axis direction.

[0075] The other end of the fourth section 52d is connected to the third wiring 53 via via 62.

[0076] The third wiring 53 has one end connected to via 62. When viewed from above, the third wiring 53 is wound clockwise.

[0077] The third wiring 53 has a first portion 53a, a second portion 53b, a third portion 53c, and a fourth portion 53d.

[0078] The first part 53a is connected at one end to via 62 and extends in the Y-axis direction. The second part 53b is connected at one end to the other end of the first part 53a and extends in the X-axis direction. The third part 53c is connected at one end to the other end of the second part 53b and extends in the opposite direction to the Y-axis direction. The fourth part 53d is connected at one end to the other end of the third part 53c and extends in the opposite direction to the X-axis direction.

[0079] The other end of the fourth section 53d is the second terminal 1b (see Figure 1).

[0080] Furthermore, the third wiring 53 has a fifth portion 53e that extends in the Y-axis direction from the second terminal 1b. One end of the fifth portion 53e is connected to the second terminal 1b. The other end of the fifth portion 53e is formed in a location that corresponds to approximately the center of the third wiring 53 when viewed from above. The other end of the fifth portion 53e has a circular shape when viewed from above.

[0081] The fifth portion 53e of the third wiring 53 corresponds to an example of the “second protrusion” of this disclosure.

[0082] The first wiring 51, the second wiring 52, and the third wiring 53 are connected in series via vias 61 and 62 to form an inductor L1.

[0083] Figure 10 is a diagram showing the first and third wiring of the filter circuit of the second embodiment superimposed.

[0084] The other end (circular portion) of the fifth part 51e of the first wiring 51 and the other end (circular portion) of the fifth part 53e of the third wiring 53 overlap when viewed from above.

[0085] One end of the first portion 51a of the first wiring 51 is connected to the first terminal 1a of the filter circuit 1A. One end of the fifth portion 51e of the first wiring 51 is connected to the first portion 51a. Also, one end of the fifth portion 53e of the third wiring 53 is connected to the second terminal 1b of the filter circuit 1A. Therefore, the overlapping portion of the fifth portion 51e of the first wiring 51 and the fifth portion 53e of the third wiring 53 constitutes the capacitor C1 (see Figure 1).

[0086] The other end (circular portion) of the fifth part 51e of the first wiring 51 is larger than the other end (circular portion) of the fifth part 53e of the third wiring 53 when viewed from above. That is, the other end of the fifth part 51e of the first wiring 51 encloses the other end of the fifth part 53e of the third wiring 53 when viewed from above.

[0087] (effect) Referring to Figure 9, the other end (circular portion) of the fifth part 51e of the first wiring 51 and the other end (circular portion) of the fifth part 53e of the third wiring 53 overlap in a plan view. Furthermore, the other end of the fifth part 51e of the first wiring 51 is larger than the other end of the fifth part 53e of the third wiring 53 in a plan view.

[0088] Therefore, even if the first wiring 51 and the third wiring 53 are formed with a relative offset along the X-axis, the change in the overlapping area between the other end of the fifth portion 51e of the first wiring 51 and the other end of the fifth portion 53e of the third wiring 53 in a plan view is suppressed. In other words, the change in the capacitance of capacitor C1 is suppressed.

[0089] As a result, the filter circuit 1A can suppress changes in its transmission characteristics even when the first wiring 51 and the third wiring 53 are formed with a relative offset along the X-axis.

[0090] Furthermore, the other end of the fifth portion 51e of the first wiring 51 and the other end of the fifth portion 53e of the third wiring 53 overlap when viewed from above. Also, the other end of the fifth portion 51e of the first wiring 51 is larger than the other end of the fifth portion 53e of the third wiring 53 when viewed from above.

[0091] Therefore, even if the first wiring 51 and the third wiring 53 are formed with a relative offset along the Y-axis, the change in the overlapping area between the other end of the fifth portion 51e of the first wiring 51 and the other end of the fifth portion 53e of the third wiring 53 in a plan view is suppressed. In other words, the change in the capacitance of capacitor C1 is suppressed.

[0092] Therefore, even if the first wiring 51 and the third wiring 53 are formed with a relative offset along the Y-axis, the filter circuit 1A can suppress changes in its transmission characteristics.

[0093] Furthermore, even if the first wiring 51 and the third wiring 53 are formed offset relative to each other along the X-axis and offset relative to each other along the Y-axis, the change in the overlapping area of ​​the other end of the fifth portion 51e of the first wiring 51 and the other end of the fifth portion 53e of the third wiring 53 in a plan view is suppressed. In other words, the change in the capacitance of capacitor C1 is suppressed.

[0094] Therefore, even if the first wiring 51 and the third wiring 53 are formed with a relative offset along the X-axis and a relative offset along the Y-axis, the filter circuit 1A can suppress changes in its transmission characteristics.

[0095] (First variation) In the examples shown in Figures 9 and 10, the other end (circular portion) of the fifth portion 51e of the first wiring is larger than the other end (circular portion) of the fifth portion 53e of the third wiring 53 when viewed from above, but the disclosure is not limited thereto. The other end of the fifth portion 53e of the third wiring 53 may be larger than the other end of the fifth portion 51e of the first wiring 51 when viewed from above.

[0096] (Second variation) In the examples shown in Figures 9 and 10, the other end of the fifth portion 51e of the first wiring and the other end of the fifth portion 53e of the third wiring 53 are assumed to be circular in shape when viewed from above, but the disclosure is not limited thereto. The other end of the fifth portion 51e of the first wiring and the other end of the fifth portion 53e of the third wiring 53 may be elliptical, rectangular, polygonal, or other shapes when viewed from above.

[0097] (Third variation) In the examples shown in Figures 9 and 10, the angle between the fifth portion 51e of the first wiring and the fifth portion 53e of the third wiring 53 is assumed to be approximately 180° in plan view, but the disclosure is not limited thereto. The angle between the fifth portion 51e of the first wiring and the fifth portion 53e of the third wiring 53 may be approximately 45°, approximately 90°, or any other angle in plan view.

[0098] (Fourth variation) In the examples shown in Figures 9 and 10, the inductor L1 is assumed to be composed of three conductive layers: a first wiring 51, a second wiring 52, and a third wiring 53. However, the disclosure is not limited to this. The inductor L1 may also be composed of two or four or more conductive layers.

[0099] (Fifth variation) In the examples shown in Figures 9 and 10, the first wiring 51, the second wiring 52, and the third wiring 53 are rectangular in shape when viewed from above, but the disclosure is not limited thereto. The first wiring 51, the second wiring 52, and the third wiring 53 may be circular or have other shapes when viewed from above.

[0100] <Example of the structure of this disclosure> This disclosure may also take the following form.

[0101] (1) A filter circuit formed on a substrate, An inductor is formed by connecting groups of wiring, each formed on a plurality of conductive layers of the substrate, in series via vias, A capacitor is formed by overlapping a first wiring having one end of the inductor within the wiring group, and a third wiring formed in a conductive layer adjacent to the conductive layer on which the first wiring is formed, with one end electrically connected via a via to a second wiring having the other end of the inductor within the wiring group, when viewed from a direction perpendicular to the main surface of the substrate. including, Filter circuit.

[0102] (2) The filter circuit described in (1) above, The first wiring and the third wiring overlap in a plus sign shape when viewed from a direction perpendicular to the main surface of the substrate. Filter circuit.

[0103] (3) The filter circuit described in (1) above, The first wiring and the third wiring overlap in a T-shape when viewed from a direction perpendicular to the main surface of the substrate. Filter circuit.

[0104] (4) A filter circuit formed on a substrate, An inductor is formed by connecting groups of wiring, each formed on a plurality of conductive layers of the substrate, in series via vias, A capacitor is formed by overlapping, when viewed from a direction perpendicular to the main surface of the substrate, a part of a first wiring having one end of the inductor within the wiring group, the tip of a first protrusion projecting inward from the first wiring, and a part of a second wiring having the other end of the inductor within the wiring group, the tip of a second protrusion projecting inward from the second wiring, when viewed from a direction perpendicular to the main surface of the substrate. including, Filter circuit.

[0105] (5) The filter circuit described in (4) above, The size of the tip of the first protrusion is larger than the size of the tip of the second protrusion when viewed from a direction perpendicular to the main surface of the substrate. Filter circuit.

[0106] (6) The filter circuit described in (4) or (5) above, The tips of the first and second protrusions are circular, elliptical, rectangular, or polygonal in shape when viewed from a direction perpendicular to the main surface of the substrate. Filter circuit.

[0107] The embodiments described above are provided to facilitate understanding of the present invention and are not intended to limit its interpretation. The present invention may be modified or improved without departing from its spirit, and equivalents thereof are also included. [Explanation of Symbols]

[0108] 1. 1A filter circuit 1a 1st terminal 1b 2nd terminal 10, 10A circuit board 31, 51 1st wiring 32, 52 2nd wiring 33, 53 3rd wiring 34 4th wiring 41, 42, 43, 61, 62 Beer C1 Capacitor L1 Inductor

Claims

1. A filter circuit formed on a substrate, An inductor is formed by connecting groups of wiring, each formed on a plurality of conductive layers of the substrate, in series via vias, A capacitor is formed by overlapping a first wiring having one end of the inductor from the wiring group, and a third wiring formed in an adjacent conductive layer in a direction perpendicular to the main surface of the substrate of the conductive layer on which the first wiring is formed, with one end electrically connected via a via to a second wiring having the other end of the inductor from the wiring group, when viewed from a direction perpendicular to the main surface of the substrate. including, Filter circuit.

2. A filter circuit according to claim 1, The first wiring and the third wiring overlap in a plus sign shape when viewed from a direction perpendicular to the main surface of the substrate. Filter circuit.

3. A filter circuit according to claim 1, The first wiring and the third wiring overlap in a T-shape when viewed from a direction perpendicular to the main surface of the substrate. Filter circuit.

4. A filter circuit formed on a substrate, An inductor is formed by connecting groups of wiring, each formed on a plurality of conductive layers of the substrate, in series via vias, A capacitor is formed by overlapping, when viewed from a direction perpendicular to the main surface of the substrate, a part of a first wiring having one end of the inductor within the wiring group, wherein the first wiring has a circular shape, and the tip of a first protrusion projecting inward from the first wiring, and a part of a second wiring having the other end of the inductor within the wiring group, and the tip of a second protrusion projecting inward from the second wiring, when viewed from a direction perpendicular to the main surface of the substrate. including, Filter circuit.

5. The filter circuit according to claim 4, The size of the tip of the first protrusion is larger than the size of the tip of the second protrusion when viewed from a direction perpendicular to the main surface of the substrate. Filter circuit.

6. A filter circuit according to claim 4 or 5, The tips of the first and second protrusions are circular, elliptical, rectangular, or polygonal in shape when viewed from a direction perpendicular to the main surface of the substrate. Filter circuit.

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