Filter device

Abstract

A filter device is provided which is reduced in size and suppresses deterioration of filter characteristics. The filter device includes a laminated substrate including a first dielectric layer, a first wiring layer including a reference electrode to which a reference potential is supplied, and a second dielectric layer having a different thickness from the first dielectric layer, which is positioned between the first dielectric layer and the first wiring layer; a series passive element provided in a series wiring electrically connecting a first terminal and a second terminal; a first parallel wiring electrically connecting the series wiring and the reference electrode; and a first parallel passive element provided in the first parallel wiring, the first parallel wiring including a first via penetrating the first dielectric layer and electrically connected to the first parallel passive element, and a second via penetrating the second dielectric layer and electrically connecting the first via and the reference electrode, the first dielectric layer being positioned between the first parallel passive element and the second dielectric layer, a cross-sectional area of the first via being different from a cross-sectional area of the second via.

Description

TECHNICAL FIELD

[0001] The present application relates to a filter device. BACKGROUND

[0002] There is a filter in which a plurality of components are mounted on a circuit substrate (see, for example, Patent Literature 1).

[0003] PRIOR ART DOCUMENT

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent Application Publication No. 2020-115616

[0006] In the filter described in Patent Literature 1, components that mount an inductor, a resonant circuit, and an elastic wave resonator, respectively, are mounted on the upper surface of the circuit substrate. A terminal is provided on the lower surface of the circuit substrate. The terminal is electrically connected to the components by a via hole that penetrates the circuit substrate.

[0007] However, in a case where the components are arranged close to each other in order to reduce the size of the filter, the power loss of a signal or the deterioration of the attenuation characteristic can sometimes be caused due to the coupling of electromagnetic fields between the components. SUMMARY

[0008] PROBLEMS TO BE SOLVED BY THE INVENTION

[0009] The present application has been achieved in view of this situation, and aims to provide a filter device that can reduce the size and suppress the deterioration of the filter characteristic.

[0010] MEANS FOR SOLVING THE PROBLEM

[0011] The filter device of one aspect of the present application includes a laminated substrate including a first dielectric layer, a first wiring layer including a reference electrode to which a reference potential is supplied, and a second dielectric layer having a thickness different from that of the first dielectric layer, between the first dielectric layer and the first wiring layer; a series passive element provided in a series wiring that electrically connects a first terminal and a second terminal; a first parallel wiring that electrically connects the series wiring and the reference electrode; and a first parallel passive element provided in the first parallel wiring, the first parallel wiring including a first via hole that penetrates the first dielectric layer and is electrically connected to the first parallel passive element, and a second via hole that penetrates the second dielectric layer and electrically connects the first via hole and the reference electrode, the first dielectric layer being between the first parallel passive element and the second dielectric layer, the cross-sectional area of the first via hole being different from that of the second via hole.

[0012] EFFECT OF THE INVENTION

[0013] According to the present application, a filter device capable of reducing the size and suppressing deterioration of filter characteristics can be provided. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 is a circuit diagram of the filter circuit 21.

[0015] Figure 2 is a view schematically showing a section parallel to the zx plane of the filter device 11 formed with the filter circuit 21.

[0016] Figure 3 is a view schematically showing each section parallel to the xy plane of the filter device 11 formed with the filter circuit 21.

[0017] Figure 4 is a circuit diagram of the equivalent circuit 22 of the filter device 11.

[0018] Figure 5 is a view schematically showing a section parallel to the zx plane of the filter device 12 formed with the filter circuit 21.

[0019] Figure 6 is a view schematically showing a section parallel to the zx plane of the filter device 13 formed with the filter circuit 21.

[0020] Figure 7 is a view schematically showing a section parallel to the zx plane of the filter device 14 formed with the filter circuit 21.

[0021] Figure 8 is a view schematically showing each section parallel to the xy plane of the filter device 14 formed with the filter circuit 21.

[0022] Figure 9 is a circuit diagram of the equivalent circuit 24 of the filter device 14.

[0023] Figure 10 is a view schematically showing a section parallel to the zx plane of the filter device 15 formed with the filter circuit of L shape.

[0024] Figure 11 is a circuit diagram of the equivalent circuit 25 of the filter device 15.

[0025] REFERENCE NUMERALS

[0026] 11, 12, 13, 14, 15... filter device

[0027] 21... filter circuit

[0028] 22, 24, 25... equivalent circuit

[0029] 31 input terminal

[0030] 32 output terminal

[0031] 40, 41a, 41b, 42, 43a, 43b, 44 via

[0032] 50 reference electrode

[0033] 51, 52 electrode

[0034] 60 series passive element

[0035] 61, 62 parallel passive element

[0036] 111 laminated substrate

[0037] 121a, 121b, 122, 123, 124 dielectric layer

[0038] 131, 132, 133, 134 wiring layer

[0039] L1 inductor

[0040] C1, C2 capacitor

[0041] S1 series wiring

[0042] Es1, Es2, Es3 electrode

[0043] Vs1, Vs2 via

[0044] P1, P2 parallel wiring

[0045] B1 branch wiring

[0046] N1, N2, N11 node DETAILED DESCRIPTION

[0047] Hereinafter, embodiments of the present application will be explained in detail with reference to the attached drawings. Note that the same reference signs are applied to the same elements, and repeated explanation will be omitted as much as possible.

[0048] [First Embodiment]

[0049] The filter device 11 and the filter circuit 21 of the first embodiment will be explained. Figure 1 is a circuit diagram of the filter circuit 21. As shown in Figure 1 , the filter circuit 21 is provided with an inductor L1, and capacitors C1 and C2.

[0050] The filter circuit 21 is a low-pass filter of a π type. In the filter circuit 21, a series wiring S1 electrically connects an input terminal 31 (a first terminal) to which, for example, an RF (Radio Frequency) signal supplied from a power amplifier is supplied and an output terminal 32 (a second terminal). A parallel wiring P1 electrically connects a node N1 provided in the series wiring S1 to a ground. A parallel wiring P2 electrically connects a node N2 provided in the series wiring S1 to the ground. Note that the parallel wiring P1 corresponds to a "first parallel wiring", and the parallel wiring P2 corresponds to a "second parallel wiring" or a "branch wiring".

[0051] The inductor L1 is provided in the series wiring S1, has a first end connected to the input terminal 31 through the node N1, and has a second end connected to the output terminal 32 through the node N2.

[0052] The capacitor C1 is provided in the parallel wiring P1, has a first end connected to the first end of the inductor L1 through the node N1, and has a second end connected to the ground. The capacitor C2 is provided in the parallel wiring P2, has a first end connected to the second end of the inductor L1 through the node N2, and has a second end connected to the ground.

[0053] Note that the structure of the filter circuit 21 being a filter of a π type is described, but is not limited thereto. The filter circuit 21 can also be a filter of other connection manners such as an L type or a T type.

[0054] In addition, the structure of the filter circuit 21 being a low-pass filter is described, but is not limited thereto. For example, by replacing the inductor L1 with a capacitor and replacing the capacitors C1 and C2 with inductors, respectively, the filter circuit 21 can also be a high-pass filter. In addition, the filter circuit 21 can also be a band-pass filter or a band-stop filter, or the like.

[0055] In addition, in the filter circuit 21, the structure of supplying a signal to the input terminal 31 is described, but is not limited thereto. The structure of supplying a signal to the output terminal 32 can also be used.

[0056] In the drawings, an x-axis, a y-axis, and a z-axis are sometimes shown. The x-axis, the y-axis, and the z-axis form a right-hand system of three-dimensional orthogonal coordinates. Hereinafter, the direction of the arrow of the x-axis is sometimes referred to as the x-axis + side, and the direction opposite to the arrow is sometimes referred to as the x-axis - side, and the same applies to the other axes. Note that the z-axis + side and the z-axis - side are sometimes referred to as the "upper side" and the "lower side", respectively. In addition, the direction of the z-axis is sometimes referred to as the "thickness direction". In addition, a plane orthogonal to the x-axis, the y-axis, or the z-axis is sometimes referred to as the yz plane, the zx plane, or the xy plane, respectively. Here, the direction of rotation clockwise when the lower side is viewed from the upper side is defined as the clockwise direction cw. In addition, the direction of rotation counterclockwise when the lower side is viewed from the upper side is defined as the counterclockwise direction ccw.

[0057] Figure 2 is a view schematically showing a cross section parallel to the zx plane of the filter device 11 formed with the filter circuit 21. Figure 3 is a view schematically showing each cross section parallel to the xy plane of the filter device 11 formed with the filter circuit 21.

[0058] As shown in Figure 2 and Figure 3 , the filter device 11 includes the series passive element 60, the parallel passive elements 61 (first parallel passive element) and 62 (second parallel passive element), the multilayer substrate 111, the series wiring S1, and the parallel wirings P1 and P2. The parallel wiring P2 is a wiring independent of the parallel wiring P1. The parallel wiring P1 includes the vias 41a (first via), 41b, and 42 (second via), and the electrode 51. The parallel wiring P2 includes the vias 43a (third via), 43b, and 44 (fourth via), and the electrode 52. In the present embodiment, each via is formed of a conductive material, and has a cylindrical shape extending in the thickness direction. Note that the shape of each via can be any shape.

[0059] The multilayer substrate 111 includes the dielectric layers 121a (first dielectric layer), 121b, 122 (second dielectric layer), 123, and 124, and the wiring layers 131 (first wiring layer), 132 (second wiring layer), 133, and 134.

[0060] The dielectric layers 121b, 121a, 122, 123, and 124 are provided in this order from the upper side toward the lower side. The dielectric layer 122 is, for example, a core layer. The dielectric layers 121b, 121a, 123, and 124 are, for example, formed of prepregs.

[0061] Dielectric layers 121b, 121a, 122, 123, and 124 each have a surface that is substantially parallel to the xy plane and faces upward (hereinafter sometimes referred to as the upper surface) and a surface that is substantially parallel to the xy plane and faces downward (hereinafter sometimes referred to as the lower surface). The upper surface of dielectric layer 122 is opposite to the lower surface of dielectric layer 121a, which is located above dielectric layer 122. The same applies to the other dielectric layers. It should be noted that the upper and lower surfaces may also have bumps or depressions generated during manufacturing or recesses for setting wiring layers.

[0062] A wiring layer 131 is provided between dielectric layer 122 and dielectric layer 123. Wiring layer 131 includes a reference electrode 50 supplied with a reference potential. The reference electrode 50 is, for example, an electrode formed over the entire area of ​​the lower surface of dielectric layer 122 and connected to ground. It should be noted that the reference electrode 50 does not necessarily have to be formed over the entire area of ​​the lower surface of dielectric layer 122; it only needs to be formed over at least a portion of the lower surface of dielectric layer 122.

[0063] For example, a wiring layer 134 is provided between dielectric layer 123 and dielectric layer 124. For example, a wiring layer 133 is provided between dielectric layer 121a and dielectric layer 121b. A plurality of vias 40 penetrating dielectric layers 123 and 124 are provided. The upper end of the via 40 is electrically connected to the reference electrode 50.

[0064] Dielectric layer 122 is located between dielectric layer 121a and wiring layer 131, and has a thickness T2 different from the thickness T1 of dielectric layer 121a. Here, "thickness" refers to the size of the dielectric layer in the direction in which dielectric layers 121b to 124 are stacked in the laminated substrate 111, i.e., the distance between the upper and lower sides of the dielectric layer. In this embodiment, thickness T1 is smaller than thickness T2. It should be noted that thickness T1 can also be larger than thickness T2.

[0065] The dielectric layer 121a is located between the parallel passive elements 61 and 62 and the series passive element 60 and the dielectric layer 122. In this embodiment, the parallel passive elements 61 and 62 and the series passive element 60 are disposed on the upper side of the dielectric layer 121b.

[0066] The following is for reference Figure 2 and Figure 3 The layout of each passive component, via, and electrode is described. Figure 3 The diagram shows a view of dielectric layer 121b and each passive component from the top, a view of dielectric layer 121a from the top, a view of dielectric layer 122 and wiring layer 132 from the top, and a view of wiring layer 131 from the top.

[0067] In this embodiment, the filter device 11 is provided in a corner of the x-axis + side and the y-axis - side of the laminated substrate 111 when viewed from above the upper side of the dielectric layer 121b in the z-axis direction. The shunt passive element 61, the series passive element 60, and the shunt passive element 62 are each a surface mount device (SMD) that functions as a capacitor Cl, an inductor LI, and a capacitor C2, respectively. The shunt passive element 61, the series passive element 60, and the shunt passive element 62 are provided in this order from the x-axis + side toward the x-axis - side.

[0068] The series wiring S1 includes, for example, electrodes Es1, Es2, and Es3, and vias Vs1 and Vs2. The electrodes Es1 and Es2 are formed on the upper side of the dielectric layer 121b. The electrode Es3 is formed on the wiring layer 132. The vias Vs1 and Vs2 each penetrate the dielectric layers 121b and 121a substantially in parallel with the z-axis.

[0069] The electrode Es1 has a first end connected to the input terminal 31 (not shown) and a second end. The series passive element 60 has a first end connected to the second end of the electrode Es1 through a pad 60a and a second end. The electrode Es2 has a first end connected to the second end of the series passive element 60 through a pad 60b and a second end.

[0070] The upper side end portion of the via Vs1 is connected to the second end of the electrode Es2 through a pad 62a. The lower side end portion of the via Vs1 is connected to the upper side end portion of the via Vs2. The electrode Es3 has a first end connected to the lower side end portion of the via Vs2 and a second end connected to the output terminal 32 (not shown).

[0071] In this embodiment, the shunt wiring P1 includes the vias 41b, 41a, and 42, and the electrode 51. The shunt wiring P2 includes the vias 43b, 43a, and 44, and the electrode 52.

[0072] The vias 41b and 43b each penetrate the dielectric layer 121b substantially in parallel with the z-axis. The vias 41b and 43b each overlap the shunt passive elements 61 and 62 when viewed from above the upper side of the dielectric layer 121b in the z-axis direction. The diameter of the via 41b is substantially the same as the diameter of the via 43b, for example.

[0073] The shunt passive element 61 electrically connects the series wiring S1 and the via 41b. Specifically, the shunt passive element 61 has a first end connected to the electrode Es1 through a pad 61a and a second end connected to the upper side end portion of the via 41b through a pad 61b.

[0074] The parallel passive element 62 electrically connects the series wiring S1 and the via 43b. In detail, the parallel passive element 62 has a first end connected to the second end of the electrode Es2 through a pad 62a, and a second end connected to the upper side end portion of the via 43b through a pad 62b.

[0075] The vias 41a and 43a penetrate the dielectric layer 121a substantially in parallel with the z-axis. In the present embodiment, the vias 41a and 43a each have a diameter substantially the same as the diameter of the via 41b and the diameter of the via 43b. When the upper side surface of the dielectric layer 121a is viewed in the z-axis direction, the vias 41a and 43a each substantially completely overlap the vias 41b and 43b, respectively. The upper side end portion of the via 41a and the upper side end portion of the via 43a are connected to the lower side end portion of the via 41b and the lower side end portion of the via 43b, respectively.

[0076] The wiring layer 132 is located on the opposite side of the wiring layer 131 with the dielectric layer 122 as a reference. In the present embodiment, the wiring layer 132 is located between the dielectric layer 121a and the dielectric layer 122.

[0077] The wiring layer 132 includes the electrode 51 (first electrode) and the electrode 52 (second electrode). The electrode 51 is routed from the via 41a and electrically connects the via 41a and the via 42. The electrode 52 is routed from the via 43a and electrically connects the via 43a and the via 44. Note that "routed" here means "extended to have a prescribed length".

[0078] Note that the wiring layer 132 can also be located between the dielectric layer 121a and the dielectric layer 121b. In this case, when the upper side surface of the dielectric layer 121a is viewed in the z-axis direction, the vias 41a and 43a are each provided so as not to overlap the vias 41b and 43b, for example. The electrode 51 electrically connects the upper side end portion of the via 41a and the lower side end portion of the via 41b. The electrode 52 electrically connects the upper side end portion of the via 43a and the lower side end portion of the via 43b.

[0079] In addition, the wiring layer 132 can also be provided on the upper side surface of the dielectric layer 121b. In this case, when the upper side surface of the dielectric layer 121b is viewed in the z-axis direction, the vias 41b and 43b are each provided so as not to overlap the parallel passive elements 61 and 62. The electrode 51 electrically connects the upper side end portion of the via 41b and the second end of the parallel passive element 61. The electrode 52 electrically connects the upper side end portion of the via 43b and the second end of the parallel passive element 62.

[0080] The electrodes 51 and 52 are each wound in the plane in which the wiring layer 132 extends. In addition, the direction in which the electrode 51 is wound and the direction in which the electrode 52 is wound are opposite to each other. In detail, the electrode 51 has a first end connected to the lower side end portion of the via 41a, and a second end located on the x-axis- side of the first end. The electrode 51 is wound in the xy plane from the first end to the second end in the counterclockwise direction ccw by more than 1 / 4 turn and less than 3 / 4 turn.

[0081] The electrode 52 has a first end connected to the lower side end portion of the via 43a, and a second end located on the x-axis+ side of the first end. The electrode 52 is wound in the xy plane from the first end to the second end in the clockwise direction cw by more than 1 / 4 turn and less than 3 / 4 turn.

[0082] The via 42 penetrates the dielectric layer 122 substantially in parallel with the z-axis, and has a cross-sectional area different from that of the via 41a. In addition, the via 42 electrically connects the electrode 51 and the reference electrode 50. In detail, the via 42 has a diameter larger than that of the via 41a. That is, the "cross-sectional area" referred to here means the area in the case where the via is sectioned in a direction orthogonal to the stacking direction of the dielectric layers 121 to 124, and the diameter of the via is one specific example thereof.

[0083] Note that, in the case where the diameter of the via that penetrates a certain dielectric layer has changed in that dielectric layer due to manufacturing variation or the like, the cross-sectional area of the portion having the thickest diameter among the diameters of the via can be set as the cross-sectional area of the via. In addition, the shape of the cross section of the via is not limited to a circular shape, and can be a polygonal shape such as a triangular shape or a quadrangular shape. In this case, in the case where the cross-sectional area of the via has changed in the dielectric layer, the largest cross-sectional area among the cross-sectional areas of the via can be set as the cross-sectional area of the via.

[0084] When the upper side surface of the dielectric layer 122 is viewed in the z-axis direction, the via 42 is located on the x-axis- side of the via 41a and does not overlap the via 41a. The upper side end portion and the lower side end portion of the via 42 are connected to the second end of the electrode 51 and the reference electrode 50, respectively.

[0085] The via 44 penetrates the dielectric layer 122 substantially in parallel with the z-axis, and has a cross-sectional area different from that of the via 43a. In addition, the via 44 electrically connects the electrode 52 and the reference electrode 50. In detail, the via 44 has a diameter larger than that of the via 43a, for example, substantially the same diameter as that of the via 42. When the upper side surface of the dielectric layer 122 is viewed in the z-axis direction, the via 44 is located on the x-axis+ side of the via 43a and does not overlap the via 43a. The upper side end portion and the lower side end portion of the via 44 are connected to the second end of the electrode 52 and the reference electrode 50, respectively.

[0086] The distance D2 between the via 42 and the via 44 is shorter than the distance Dl between the via 41a and the via 43a. Specifically, the distance D2 is, for example, the length of the shortest straight line connecting the center axis of the via 42 and the center axis of the via 44. The distance Dl is, for example, the length of the shortest straight line connecting the center axis of the via 41a and the center axis of the via 43a. Thus, the vias farther from the passive elements 60 to 62 are closer to each other than the vias closer to the passive elements 60 to 62. Therefore, when the filter device 11 is viewed in the z-axis direction, it is easy to form the vias 42 and 44 inside the region in which the passive elements 61, 62, and 63 are provided. Therefore, it is possible to minimize the space of the laminated substrate 111 occupied by the vias 41a and 43a, and thus, it is easy to achieve the miniaturization of the filter device 11.

[0087] Figure 4 is a circuit diagram of the equivalent circuit 22 of the filter device 11. As shown in Figure 4 , each via and each electrode function as an inductor. In addition, each electrode also functions as a capacitor.

[0088] Specifically, the vias 41b, 41a, and 42 included in the parallel wiring P1 function as the inductors Ll l, L12, and L14, respectively. The vias 43b, 43a, and 44 included in the parallel wiring P2 function as the inductors L21, L22, and L24, respectively.

[0089] The inductance of the vias 41b, 41a, 42, 43b, 43a, and 44 has a value corresponding to the shape of the via. Specifically, the larger the diameter of the via, the smaller the inductance of the via. In addition, the larger the length of the via, that is, the thickness of the dielectric layer in which the via is provided, the larger the inductance of the via.

[0090] Therefore, by adjusting the diameter of the via and the thickness of the dielectric layer in which the via is provided, it is possible to adjust the inductance of the via.

[0091] In addition, the electrode 51 included in the parallel wiring P1 functions as the inductor L13, and forms the capacitor Cll with the reference electrode 50. Similarly, the electrode 52 included in the parallel wiring P2 functions as the inductor L23, and forms the capacitor C21 with the reference electrode 50.

[0092] The inductance of the electrodes 51 and 52 has a value corresponding to the number of turns, the width, and the length of the electrode, and the like. In addition, the capacitance of the capacitor formed between the electrode 51 or 52 and the reference electrode 50 has a value corresponding to the distance between the electrode and the reference electrode 50 and the area of the electrode, and the like.

[0093] Therefore, by adjusting the shape and arrangement of the electrode 51, the inductance of the electrode 51 can be adjusted, and the capacitance of the capacitor C11 formed between the electrode 51 and the reference electrode 50 can be adjusted. The same applies to the electrode 52 and the electrode 51.

[0094] As above, in the equivalent circuit 22, the inductors L11, L12, L13, and L14 are connected in series between the capacitor C1 and the ground, i.e., the reference electrode 50. The capacitor C11 is connected between the midpoint of the inductor L13 and the ground.

[0095] The inductors L21, L22, L23, and L24 are connected in series between the capacitor C2 and the ground. The capacitor C21 is connected between the midpoint of the inductor L23 and the ground.

[0096] [Second Embodiment]

[0097] The filter device 12 of the second embodiment will be described. In the second embodiment and later, the description of matters common to the first embodiment will be omitted, and only the different points will be described. In particular, the same effects resulting from the same structures will not be mentioned in each embodiment in succession.

[0098] Figure 5 is a view schematically showing a cross section parallel to the zx plane of the filter device 12 in which the filter circuit 21 is formed. As shown in Figure 5 The filter device 12 of the second embodiment differs from the filter device 11 of the first embodiment in that the distance D2 between the via 42 and the via 44 is longer than the distance D1 between the via 41a and the via 43a.

[0099] In the filter device 12, the diameter of the via 41a and the diameter of the via 43a are smaller than the diameter of the via 42 and the diameter of the via 44, respectively. The distance D1 between the central axis of the via 41a and the central axis of the via 43a is shorter than the distance D2 between the central axis of the via 42 and the central axis of the via 44.

[0100] Generally, when signals flow through two vias arranged in parallel, the greater the diameter of the via, the greater the coupling of electromagnetic fields between the two vias. As with the filter device 12, by adopting a structure in which the distance D2 between the vias 42 and 44, which have large diameters, is longer than the distance D1 between the vias 41a and 43a, which have small diameters, the coupling of electromagnetic fields between the vias 42 and 44 can be reduced, and the degradation of the filter characteristics can be effectively suppressed.

[0101] [Third Embodiment]

[0102] The filter device 13 of the third embodiment will be described. Figure 6is a diagram schematically showing a cross section of the filter device 13 formed with the filter circuit 21, in parallel with the zx plane. As shown in Figure 6 The filter device 13 of the third embodiment differs from the filter device 11 of the first embodiment in that the diameter of the via 41a and the diameter of the via 43a are larger than the diameter of the via 42 and the diameter of the via 44, respectively.

[0103] In the filter device 13, the distance Dl between the center axis of the via 41a and the center axis of the via 43a is longer than the distance D2 between the center axis of the via 42 and the center axis of the via 44.

[0104] As with the filter device 13, by adopting a structure in which the distance Dl between the vias 41a and 43a having large diameters is longer than the distance D2 between the vias 42 and 44 having small diameters, the coupling of electromagnetic fields between the vias 41a and 43a can be reduced, and the degradation of filter characteristics can be effectively suppressed.

[0105] [Fourth Embodiment]

[0106] The filter device 14 of the fourth embodiment will be described. Figure 7 is a diagram schematically showing a cross section of the filter device 14 formed with the filter circuit 21, in parallel with the zx plane. As shown in Figure 7 The filter device 14 of the fourth embodiment differs from the filter device 11 of the first embodiment in that the vias 42 and 44 are collectively one via 42.

[0107] Figure 8 is a diagram schematically showing each cross section of the filter device 14 formed with the filter circuit 21, in parallel with the xy plane. Note that the observation method of Figure 8 is the same as that of Figure 3 .

[0108] As shown in Figure 7 and Figure 8 , the parallel wiring P1 includes the vias 41b, 41a, and 42, and the electrode 51. The parallel wiring P2 does not include the via 44 as compared with the parallel wiring P2 shown in Figure 2 . That is, the parallel wiring P2 includes the vias 43b and 43a, and the electrode 52. The parallel wiring P2 is also a branch wiring branched from the parallel wiring P1. Specifically, the parallel wiring P2 is connected in common with the parallel wiring P1 in the wiring layer 132, and is a wiring (branch wiring) independent of the parallel wiring P1.

[0109] The wiring layer 132 includes the electrode 51 (first electrode) and the electrode 52 (second electrode). The electrode 51 is routed from the via 41a, and electrically connects the via 41a and the via 42. The electrode 52 is routed from the via 43a, and electrically connects the via 43a and the via 42.

[0110] In detail, the electrode 51 has a first end connected to the lower side end portion of the via 41a, and a second end between the lower side end portion of the via 41a and the lower side end portion of the via 43a. The electrode 51 is wound more than 1 / 4 turn and less than 3 / 4 turn in the xy plane in the counterclockwise direction ccw from the first end to the second end.

[0111] The electrode 52 has a first end connected to the lower side end portion of the via 43a, and a second end at the same position as the position of the second end of the electrode 51. The electrode 52 is wound more than 1 / 4 turn and less than 3 / 4 turn in the clockwise direction cw in the xy plane from the first end to the second end. Note that the connection portion 51a of the electrodes 51 and 52 and the second end of the electrode 51 are common to the electrodes 51 and 52.

[0112] The via 42 has a diameter larger than that of the via 41a and larger than that of the via 43a. When the upper side of the dielectric layer 122 is viewed in the z-axis direction, the via 42 is positioned between the via 41a and the via 43a, and does not overlap either of the vias 41a and 43a. The upper side end portion of the via 42 is connected to the second end of the electrode 51 and the second end of the electrode 52. The lower side end portion of the via 42 is connected to the reference electrode 50.

[0113] Figure 9 is a circuit diagram of the equivalent circuit 24 of the filter device 14. As shown in Figure 9 , in the equivalent circuit 24, the inductors L11, L12, L13, and L14 are connected in series between the capacitor Cl and ground. The capacitor Cll is connected between the midpoint of the inductor L13 and ground.

[0114] The inductors L21, L22, and L23 are connected in series between a node N11 and the capacitor C2, the node N11 being between the inductors L13 and L14. The capacitor C21 is connected between the midpoint of the inductor L23 and ground.

[0115] [Fifth Embodiment]

[0116] The filter device 15 of the fifth embodiment will be described. Figure 10 is a view schematically showing a cross section of the filter device 15 in which an L-shaped filter circuit is formed, in parallel with the zx plane. As shown in Figure 10 , the filter device 15 of the fifth embodiment differs from the filter device 14 of the fourth embodiment in that no shunt passive element 62 is provided.

[0117] As shown in Figure 10 , the parallel wiring P1 is the same as the parallel wiring P1 shown in Figure 7 . The branch wiring B1 includes the vias 43b and 43a and the electrode 52.Figure 10 The via holes 43b and 43a and the electrode 52 shown in FIG. 2 are respectively the same as those shown in FIG. 1. Figure 7 Note that, in the branch wiring Bl, the upper side end portion of the via hole 43b is open.

[0118] Figure 11 is a circuit diagram of the equivalent circuit 25 of the filter device 15. As shown in FIG. 5, the equivalent circuit 25 is different from the equivalent circuit 24 shown in FIG. 4 in that the capacitor C2 is not provided. Figure 11 Figure 9 Thus, the second end of the inductor LI and the output terminal 32 are electrically insulated from the inductor L21.

[0119] In detail, in the equivalent circuit 25, the inductors LI 1, LI 2, LI 3, and LI 4 are connected in series between the capacitor CI and the ground. The capacitor CIl is connected between the midpoint of the inductor LI 3 and the ground.

[0120] The branch wiring Bl branches from a node Nl 1 located between the inductor LI 3 and the inductor LI 4. In the branch wiring Bl, the inductor L23 has a first end connected to the node Nl 1 and a second end. The inductor L21 has a first end connected to the second end of the inductor L23 through the inductor L22 and a second end which is an open end. The capacitor C21 is connected between the midpoint of the inductor L23 and the ground.

[0121] Thus, since the second end of the inductor L21 is an open end, the branch wiring Bl functions as an open stub circuit.

[0122] Note that, in the filter devices 11 to 13, the structure in which the parallel wirings PI and P2 are provided is described, but the present application is not limited thereto. The structure in which either one of the parallel wirings PI and P2 is provided can also be employed. Even in such a structure, the object of the present application can be achieved.

[0123] In addition, in the filter devices 11 to 14, the structure in which the parallel wiring PI branches from between the input terminal 31 and the first end of the inductor LI and the parallel wiring P2 branches from between the output terminal 32 and the second end of the inductor LI is described, but the present application is not limited thereto. The structure in which the parallel wirings PI and P2 branch from between the input terminal 31 and the first end of the inductor LI or the structure in which the parallel wirings PI and P2 branch from between the output terminal 32 and the second end of the inductor LI can also be employed.

[0124] ​In addition, in the filter devices 11 to 15, a structure in which the dielectric layer 121b is provided between the series passive element 60 and the parallel passive elements 61 and 62 and the dielectric layer 121a is described, but is not limited thereto. A structure in which the dielectric layer 121b is not provided and the series passive element 60 and the parallel passive elements 61 and 62 are located on the upper side of the dielectric layer 121a can also be employed.

[0125] In addition, in the filter devices 11 to 15, a structure in which the wiring layer 132 is provided between the dielectric layer 121a and the dielectric layer 122 is described, but is not limited thereto. A structure in which one or more dielectric layers are provided between the dielectric layer 121a and the dielectric layer 122 can also be employed.

[0126] In addition, in the filter devices 11 to 15, a structure in which the reference electrode 50 is connected to the ground is described, but is not limited thereto. A structure in which the reference electrode 50 is connected to, for example, a constant voltage source that is a power supply of a power amplifier can also be employed.

[0127] In addition, in the filter devices 11 to 15, a structure in which the passive elements 60, 61, and 62 are each formed of an SMD is described, but is not limited thereto. At least one of the passive elements 60, 61, and 62 can also be formed of a pattern of a wiring provided to the multilayer substrate 111.

[0128] In addition, in the filter devices 11 to 14, a structure in which the electrodes 51 and 52 are wound is described, but is not limited thereto. A structure in which the electrodes 51 and 52 are not wound, for example, by having a linear shape can also be employed.

[0129] In addition, in the filter device 12, a structure in which the diameter of the via 41a and the diameter of the via 43a are each smaller than the diameter of the via 42 and the diameter of the via 44 is described, but is not limited thereto. A structure in which the diameter of the via 41a and the diameter of the via 43a are each larger than the diameter of the via 42 and the diameter of the via 44 can also be employed.

[0130] The above describes an example embodiment of the present application. In the filter device 11, 12, 13, 14, and 15, the multilayer substrate 111 includes the dielectric layer 121a, the wiring layer 131 including the reference electrode 50 to which a reference potential is supplied, and the dielectric layer 122 having a thickness T2 different from the thickness Tl of the dielectric layer 121a, between the dielectric layer 121a and the wiring layer 131. The series passive element 60 is provided in a series wiring S1 electrically connecting the input terminal 31 and the output terminal 32. The parallel wiring P1 electrically connects the series wiring S1 and the reference electrode 50. The parallel passive element 61 is provided in the parallel wiring P1. The parallel wiring P1 includes the via 41a penetrating the dielectric layer 121a and electrically connected to the parallel passive element 61, and the via 42 penetrating the dielectric layer 122 and electrically connecting the via 41a and the reference electrode 50. The dielectric layer 121a is between the parallel passive element 61 and the dielectric layer 122. Further, the cross-sectional area of the via 41a is different from the cross-sectional area of the via 42.

[0131] Thus, by adopting the structure in which the thickness Tl is different from the thickness T2 and the cross-sectional area of the via 41a is different from the cross-sectional area of the via 42, the length and the cross-sectional area of the via 41a and the via 42 can be made different from each other. That is, the parasitic inductance of the via 41a and the parasitic inductance of the via 42 can be made different from each other. That is, in the multilayer substrate 111 formed by the thicknesses Tl and T2 and the cross-sectional areas of the via 41a and the via 42 appropriately designed, the parasitic inductance of the via 41a and the parasitic inductance of the via 42 can be set as the circuit elements adjustable in the filter circuit 21, and thus the degree of freedom of adjustment of the filter characteristics can be improved. Thus, for example, even in a case where the series passive element 60 and the parallel passive element 61 are arranged close to each other in order to reduce the size of the filter device, and the power loss of a signal or the deterioration of the attenuation characteristics is caused due to the coupling of electromagnetic fields between these passive elements, the increase in the power loss of the signal and the deterioration of the attenuation characteristics can be suppressed by appropriately adjusting the filter characteristics. Therefore, a filter device capable of reducing the size and suppressing the deterioration of the filter characteristics can be provided.

[0132] Further, in the filter device 11, 12, 13, 14, and 15, the multilayer substrate 111 further includes a wiring layer 132 located on the opposite side of the wiring layer 131 with the dielectric layer 122 as a reference. The parallel wiring P1 further includes an electrode 51 which is routed from the via 41a in the wiring layer 132 and electrically connects the via 41a and the via 42 or the parallel passive element 61.

[0133] With such a structure, as a circuit element capable of being adjusted in the filter circuit 21, a capacitor having a parasitic capacitance can be further formed between the electrode 51 drawn from the via 41a and the reference electrode 50. Thus, the degree of freedom of adjustment of the filter characteristic can be further improved, and therefore, the size can be reduced, and the degradation of the filter characteristic can be effectively suppressed.

[0134] Further, in the filter devices 11, 12, 13, 14, and 15, the electrode 51 is wound in the wiring layer 132.

[0135] With such a structure, as a circuit element capable of being adjusted in the filter circuit 21, an inductor L13 having a parasitic inductance can be further formed by the electrode 51 wound. Thus, the degree of freedom of adjustment of the filter characteristic can be further improved, and therefore, the size can be reduced, and the degradation of the filter characteristic can be effectively suppressed.

[0136] Further, in the filter devices 11, 12, and 13, the parallel wiring P2 electrically connects the series wiring S1 and the reference electrode 50, and is independent from the parallel wiring P1. The parallel passive element 62 is provided to the parallel wiring P2. The parallel wiring P2 includes a via 43a that penetrates the dielectric layer 121a and is electrically connected to the parallel passive element 62, and a via 44 that penetrates the dielectric layer 122 and electrically connects the via 43a and the reference electrode 50. The dielectric layer 121a is located between the parallel passive element 62 and the dielectric layer 122. Also, the cross-sectional area of the via 43a is different from the cross-sectional area of the via 44.

[0137] With such a structure, in the laminated substrate 111 formed by the thicknesses T1 and T2 and the cross-sectional area of the via 43a and the cross-sectional area of the via 44 that are appropriately designed, the parasitic inductance of the via 43a and the parasitic inductance of the via 44 can be set as the circuit element capable of being adjusted in the filter circuit 21. Thus, the degree of freedom of adjustment of the filter characteristic can be further improved, and therefore, the size can be reduced, and the degradation of the filter characteristic can be effectively suppressed.

[0138] Further, in the filter device 11, the distance D2 between the via 42 and the via 44 is shorter than the distance D1 between the via 41a and the via 43a.

[0139] With such a structure, when the upper side of the dielectric layer 121a is viewed in the z-axis direction, the vias 42 and 44 can be arranged between the via 41a and the via 43a, and therefore, the filter device 11 can be formed compactly. Thus, in the laminated substrate 111, the space that can be effectively used can be more ensured.

[0140] Further, in the case where the cross-sectional area of the via 41a and the cross-sectional area of the via 43a are smaller than the cross-sectional area of the via 42 and the cross-sectional area of the via 44, respectively, as in the filter device 12, the distance Dl between the via 41a and the via 43a is shorter than the distance D2 between the via 42 and the via 44. Further, in the case where the cross-sectional area of the via 41a and the cross-sectional area of the via 43a are larger than the cross-sectional area of the via 42 and the cross-sectional area of the via 44, respectively, as in the filter device 13, the distance Dl between the via 41a and the via 43a is longer than the distance D2 between the via 42 and the via 44.

[0141] Generally, when signals flow in two vias arranged in parallel, the larger the diameter of the via, the greater the coupling of electromagnetic fields between the two vias. By adopting a structure in which the distance between vias with large diameters is longer than the distance between vias with small diameters, as in the filter devices 12 and 13, the coupling of electromagnetic fields between vias with large diameters can be reduced, and thus the deterioration of filter characteristics can be effectively suppressed.

[0142] Further, in the filter device 15, the branch wiring Bl branches from the parallel wiring Pl. The branch wiring Bl includes the via 43a that penetrates the dielectric layer 121a. Further, the via 42 electrically connects the via 43a and the reference electrode 50.

[0143] Thus, the via 43a can function as an open stub circuit, and thus the degree of freedom in adjusting filter characteristics such as the attenuation amount and the frequency band of the filter can be further increased. As a result, the size can be reduced, and the deterioration of filter characteristics can be effectively suppressed.

[0144] Further, in the filter device 14, the branch wiring (parallel wiring P2) branches from the parallel wiring Pl. The branch wiring (parallel wiring P2) includes the via 43a that penetrates the dielectric layer 121a. The via 42 electrically connects the via 43a and the reference electrode 50. The branch wiring (parallel wiring P2) electrically connects the series wiring Sl and the parallel wiring Pl. The parallel passive element 62 is provided in the branch wiring (parallel wiring P2) that electrically connects the series wiring Sl and the via 43a. The dielectric layer 121a is located between the parallel passive element 62 and the dielectric layer 122. Further, the cross-sectional area of the via 43a is different from the cross-sectional area of the via 42.

[0145] Thus, by adopting the structure in which the via hole 42 is shared in the path from the shunt passive element 61 to the reference electrode 50 and the path from the shunt passive element 62 to the reference electrode 50, it is possible to intentionally interfere with the signals transmitted in each path. Thus, it is possible to achieve filter characteristics different from those in the case where each path is independent, such as wide frequency characteristics. Thus, it is possible to improve the degree of freedom of adjustment of the filter characteristics, and therefore, it is possible to reduce the size and effectively suppress deterioration of the filter characteristics.

[0146] In addition, in the filter devices 11, 12, and 13, the laminated substrate 111 further includes a wiring layer 132 located on the opposite side of the wiring layer 131 with the dielectric layer 122 as a reference. The shunt wiring P1 further includes an electrode 51 that is routed in the wiring layer 132 from the via hole 41a and electrically connects the via hole 41a with the via hole 42 or the shunt passive element 61. The shunt wiring P2 further includes an electrode 52 that is routed in the wiring layer 132 from the via hole 43a and electrically connects the via hole 43a with the via hole 44 or the shunt passive element 62.

[0147] With such a structure, as circuit elements that can be adjusted in the filter circuit 21, it is possible to further form a capacitor having a parasitic capacitance between the electrode 51 routed from the via hole 41a and the reference electrode 50, and to further form a capacitor having a parasitic capacitance between the electrode 52 routed from the via hole 43a and the reference electrode 50. Thus, it is possible to further improve the degree of freedom of adjustment of the filter characteristics, and therefore, for example, it is possible to achieve frequency characteristics having peaks corresponding to the self-resonance frequencies of each parasitic capacitance, and the like. Thus, it is possible to reduce the size and effectively suppress deterioration of the filter characteristics.

[0148] In addition, in the filter device 14, the laminated substrate 111 further includes a wiring layer 132 located on the opposite side of the wiring layer 131 with the dielectric layer 122 as a reference. The shunt wiring P1 further includes an electrode 51 that is routed in the wiring layer 132 from the via hole 41a and electrically connects the via hole 41a with the via hole 42 or the shunt passive element 61. The branch wiring (shunt wiring P2) further includes an electrode 52 that is routed from the via hole 43a and electrically connects the via hole 43a with the via hole 42 or the shunt passive element 62.

[0149] With such a structure, as the circuit element capable of adjustment in the filter circuit 21, a capacitor having a parasitic capacitance can be further formed between the electrode 51 drawn from the via 41a and the reference electrode 50, and a capacitor having a parasitic capacitance can be further formed between the electrode 52 drawn from the via 43a and the reference electrode 50. Thus, the degree of freedom of adjustment of the filter characteristic can be further improved, and therefore, for example, a wide frequency characteristic or the like can be achieved. Thus, the size can be reduced, and the degradation of the filter characteristic can be effectively suppressed.

[0150] In addition, in the filter device 15, the laminated substrate 111 further includes a wiring layer 132 between the dielectric layer 121a and the dielectric layer 122. The parallel wiring P1 further includes an electrode 51 drawn in the wiring layer 132 from the via 41a and electrically connecting the via 41a and the via 42. The branch wiring B1 further includes an electrode 52 drawn from the via 43a and electrically connecting the via 43a and the via 42.

[0151] With such a structure, as the circuit element capable of adjustment in the filter circuit 21, a capacitor having a parasitic capacitance can be further formed between the electrode 51 drawn from the via 41a and the reference electrode 50, and a capacitor having a parasitic capacitance can be further formed between the electrode 52 drawn from the via 43a and the reference electrode 50, and therefore, the degree of freedom of adjustment of the filter characteristic can be further improved. Thus, the size can be reduced, and the degradation of the filter characteristic can be effectively suppressed.

[0152] In addition, in the filter devices 11, 12, 13, 14, and 15, the electrodes 51 and 52 are respectively wound in the wiring layer 132.

[0153] With such a structure, as the circuit element capable of adjustment in the filter circuit 21, an inductor L13 and an inductor L24 each having a parasitic inductance can be further formed by the electrodes 51 and 52 wound. Thus, the degree of freedom of adjustment of the filter characteristic can be further improved, and therefore, the size can be reduced, and the degradation of the filter characteristic can be effectively suppressed.

[0154] In addition, in the filter devices 11, 12, 13, 14, and 15, the direction in which the electrode 51 is wound and the direction in which the electrode 52 is wound are opposite to each other.

[0155] Thus, the direction of the magnetic field generated by the current flowing in the path from the parallel passive element 61 to the reference electrode 50 through the electrode 51 and the direction of the magnetic field generated by the current flowing in the path from the parallel passive element 62 to the reference electrode 50 through the electrode 52 can be made opposite to each other. Thus, the signals transmitted in the respective paths can be suppressed from interfering with each other, and therefore, the degradation of the filter characteristic can be effectively suppressed.

[0156] Note that the above-described embodiments are for facilitating understanding of the present application and are not intended to limit the interpretation of the present application. The present application can be modified / changed in various ways without departing from the spirit thereof, and equivalents thereof are also included in the scope of the present application. That is, as long as the features of the present application are possessed, the present application includes a mode in which each embodiment is appropriately designed and changed by those skilled in the art. For example, each element and its arrangement, material, condition, shape, size, and the like possessed by each embodiment are not limited to the illustrated cases and can be appropriately changed. In addition, each embodiment is illustrative, and of course, partial replacement or combination of the structures shown in different embodiments is possible, and as long as the features of the present application are included, they are also included in the scope of the present application.

Claims

1. A filter device comprising: A laminated substrate includes a first dielectric layer, a first wiring layer and a second dielectric layer, wherein the first wiring layer includes a reference electrode supplied with a reference potential, and the second dielectric layer is located between the first dielectric layer and the first wiring layer and has a thickness different from that of the first dielectric layer. A series passive component is disposed in a series wiring that electrically connects the first terminal and the second terminal; A first parallel wiring connects the series wiring to the reference electrode; as well as The first parallel passive component is disposed in the first parallel wiring. The first parallel wiring includes: The first via penetrates the first dielectric layer and is electrically connected to the first parallel passive component; as well as A second via penetrates the second dielectric layer and electrically connects the first via to the reference electrode. The first dielectric layer is located between the first parallel passive component and the second dielectric layer. The cross-sectional area of ​​the first via is different from that of the second via.

2. The filter device according to claim 1, wherein, The laminated substrate further includes a second wiring layer, which is located on the opposite side of the first wiring layer with respect to the second dielectric layer. The first parallel wiring also includes a first electrode that is wound from the first via in the second wiring layer and electrically connects the first via to the second via or the first parallel passive element.

3. The filter device according to claim 2, wherein, The first electrode is wound in the second wiring layer.

4. The filter device according to any one of claims 1 to 3, wherein, The filter device also includes: The second parallel wiring connects the series wiring to the reference electrode and is independent of the first parallel wiring. as well as The second parallel passive component is disposed in the second parallel wiring. The second parallel wiring includes: The third via penetrates the first dielectric layer and is electrically connected to the second parallel passive component; as well as A fourth via penetrates the second dielectric layer and electrically connects the third via to the reference electrode. The first dielectric layer is located between the second parallel passive component and the second dielectric layer. The cross-sectional area of ​​the third via is different from that of the fourth via.

5. The filter device according to claim 4, wherein, The distance between the second via and the fourth via is shorter than the distance between the first via and the third via.

6. The filter device according to claim 4, wherein, When the cross-sectional areas of the first via and the third via are smaller than the cross-sectional areas of the second via and the fourth via, respectively, the distance between the first via and the third via is shorter than the distance between the second via and the fourth via. When the cross-sectional areas of the first via and the third via are larger than the cross-sectional areas of the second via and the fourth via, respectively, the distance between the first via and the third via is longer than the distance between the second via and the fourth via.

7. The filter device according to any one of claims 1 to 3, wherein, The filter device also includes branch wiring branching from the first parallel wiring branch. The branch wiring includes a third via penetrating the first dielectric layer. The second via also electrically connects the third via to the reference electrode.

8. The filter device according to claim 7, wherein, The branch wiring electrically connects the series wiring to the first parallel wiring. The filter device further includes a second parallel passive element, which is disposed on the branch wiring and electrically connects the series wiring to the third via. The first dielectric layer is located between the second parallel passive component and the second dielectric layer. The cross-sectional area of ​​the third via is different from that of the second via.

9. The filter device according to claim 4, wherein, The laminated substrate further includes a second wiring layer, which is located on the opposite side of the first wiring layer with respect to the second dielectric layer. The first parallel wiring further includes a first electrode, which is wound from the first via in the second wiring layer and electrically connects the first via to the second via or the first parallel passive component. The second parallel wiring also includes a second electrode that is wound from the third via in the second wiring layer and electrically connects the third via to the fourth via or the second parallel passive element.

10. The filter device according to claim 8, wherein, The laminated substrate further includes a second wiring layer, which is located on the opposite side of the first wiring layer with respect to the second dielectric layer. The first parallel wiring further includes a first electrode, which is wound from the first via in the second wiring layer and electrically connects the first via to the second via or the first parallel passive component. The branch wiring also includes a second electrode that is wound from the third via in the second wiring layer and electrically connects the third via to the second via or the second parallel passive element.

11. The filter device according to claim 7, wherein, The laminated substrate further includes a second wiring layer located between the first dielectric layer and the second dielectric layer. The first parallel wiring further includes a first electrode, which is wound from the first via in the second wiring layer and electrically connects the first via to the second via. The branch wiring also includes a second electrode that is wound from the third via in the second wiring layer and electrically connects the third via to the second via.

12. The filter device according to any one of claims 9 to 11, wherein, The first electrode and the second electrode are respectively wound in the second wiring layer.

13. The filter device according to claim 12, wherein, The direction in which the first electrode is wound is opposite to the direction in which the second electrode is wound.

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