Filter device

Abstract

A filter device is provided with: a first body including an inductor and a capacitor; a second main body mounted on the first main body and including an elastic wave element; a filter circuit including an inductor, a capacitor, and an elastic wave element; a first capacitor; and a second capacitor. The first body also includes a first signal terminal and a second signal terminal. The filter circuit is disposed between the first signal terminal and the second signal terminal on the circuit structure. The first capacitor is provided in a first path connecting the first signal terminal and the filter circuit. The second capacitor is provided in a second path connecting the second signal terminal and the filter circuit.

Description

Technical Field

[0001] The present invention relates to a filter device including a main body and a mounted device mounted on the main body. Background Art

[0002] Filters such as low-pass filters, high-pass filters, and bandpass filters are constructed using multiple resonators. Known resonators used in these filters include LC resonators, which are constructed using inductors and capacitors, and elastic wave resonators, which are constructed using elastic wave elements. An elastic wave element is an element that utilizes elastic waves. These include surface acoustic wave elements, which utilize surface acoustic waves, and bulk acoustic wave elements, which utilize bulk acoustic waves.

[0003] For example, International Publication No. 2009 / 136472 discloses an elastic wave filter device comprising a first elastic wave filter chip and a second elastic wave filter chip mounted on a multilayer substrate. In this elastic wave filter device, the first elastic wave filter chip is disposed between an input terminal and a receiving terminal, while the second elastic wave filter chip is disposed between the input terminal and a transmitting terminal.

[0004] In filter devices using elastic wave elements, multiple elements may be provided on the front and rear sides of the elastic wave element. Consider the case where a signal with a frequency lower than the filter section's passband is input as interference wave into a filter device including a filter section containing an elastic wave element. If the interference wave is input into the multiple elements on the front and rear sides of the filter section, in addition to the interference wave, higher harmonics with higher frequencies than the interference wave are output from the multiple elements. If the frequency of the higher harmonics falls within the filter section's passband, the higher harmonics act as noise and overlap with the signal to be removed by the filter device.

[0005] Furthermore, filter devices generally have multiple terminals. These terminals include multiple signal terminals for signal input or output and at least one ground terminal connected to a grounding member. If the multiple terminals are electrically connected, static discharge can cause a larger current to flow between the multiple terminals. In particular, in filter devices using elastic wave elements, if the elastic wave element is placed between two electrically connected terminals, there is a risk of static discharge damaging the elastic wave element.

[0006] Furthermore, filter devices using elastic wave elements, such as the elastic wave filter device disclosed in International Publication No. 2009 / 136472, include a first device containing the elastic wave element and a second device containing other components. The first device is mounted on the second device. The aforementioned problem is not limited to cases where the first device contains the elastic wave element but also applies to cases where the first device contains any other element susceptible to electrostatic damage. Summary of the Invention

[0007] (1) Technical issues to be resolved

[0008] An object of the present invention is to provide a filter device capable of improving reliability.

[0009] (2) Technical solution

[0010] The filter device of the present invention comprises: a first body including a first element; a second body mounted on the first body and including a second element; a filter circuit including a first element and a second element; a first capacitor; and a second capacitor. The first body further includes a first signal terminal and a second signal terminal. The filter circuit is arranged between the first signal terminal and the second signal terminal in terms of circuit structure. The first capacitor is arranged in a first path connecting the first signal terminal to the filter circuit. The second capacitor is arranged in a second path connecting the second signal terminal to the filter circuit.

[0011] (3) Beneficial effects

[0012] In the filter device of the present invention, the first capacitor is provided in the first path connecting the first signal terminal and the filter circuit, and the second capacitor is provided in the second path connecting the second signal terminal and the filter circuit. Thus, according to the present invention, a filter device with improved reliability can be realized.

[0013] Other objects, features, and advantages of the present invention will become more apparent from the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a circuit diagram showing a circuit configuration of a filter device according to one embodiment of the present invention.

[0015] Figure 2 It is a perspective view showing a filter device according to one embodiment of the present invention.

[0016] Figure 3 It is a perspective view showing a first body of a filter device according to one embodiment of the present invention.

[0017] Figure 4 It is a perspective view showing a first body of a filter device according to one embodiment of the present invention.

[0018] Figures 5A to 5C Yes Figures 2 to 4 An explanatory diagram of the pattern formation surface of the first to third dielectric layers in the first body shown.

[0019] Figures 6A to 6C Yes Figures 2 to 4 An explanatory diagram of the pattern formation surface of the fourth to sixth dielectric layers in the first body shown.

[0020] Figure 7A Yes Figures 2 to 4 An explanatory diagram of the pattern formation surface of the seventh to thirteenth dielectric layers in the first body shown.

[0021] Figure 7B as well as Figure 7C Yes Figures 2 to 4 An explanatory diagram of the pattern formation surface of the fourteenth and fifteenth dielectric layers in the first body shown.

[0022] Figures 8A to 8C Yes Figures 2 to 4 FIG. 1 is an explanatory diagram of the pattern formation surface of the sixteenth to eighteenth dielectric layers in the first body.

[0023] Figure 9 Yes Figures 2 to 4 FIG. 1 is an explanatory diagram of the electrode forming surface of the eighteenth dielectric layer in the first body.

[0024] Figure 10 This is a perspective view showing the interior of a first body in one embodiment of the present invention. DETAILED DESCRIPTION

[0025] Hereinafter, the embodiments of the present invention will be described in detail with reference to the accompanying drawings. Figure 1 The general structure of a filter device 1 according to one embodiment of the present invention will be described. This embodiment of the filter device 1 includes: a first signal terminal 2; a second signal terminal 3; and a filter circuit 10 disposed between the first and second signal terminals 2 and 3 in terms of circuit structure. In this embodiment, filter circuit 10 specifically constitutes a high-pass filter. In this application, the term "circuit structure" refers to the configuration on a circuit diagram, not the physical configuration.

[0026] The first signal terminal 2 and the second signal terminal 3 are signal terminals for inputting or outputting signals, respectively. That is, when a signal is input to the first signal terminal 2, a signal is output from the second signal terminal 3. When a signal is input to the second signal terminal 3, a signal is output from the first signal terminal 2.

[0027] The filter device 1 further includes: a first path 5, which connects the first signal terminal 2 and the filter circuit 10, and extends from the first signal terminal 2 to the filter circuit 10; a second path 6, which connects the second signal terminal 3 and the filter circuit 10, and extends from the second signal terminal 3 to the filter circuit 10; a first low-pass filter 20 provided on the first path 5; and a second low-pass filter 30 provided on the second path 6. In this embodiment, the filter circuit 10, the first low-pass filter 20, and the second low-pass filter 30 are connected in series, in this order, from the first signal terminal 2 toward the second signal terminal 3.

[0028] The filter device 1 further includes capacitors C1 and C2 provided in the first path 5, and capacitors C3 and C4 provided in the second path 6. Capacitor C1 is provided between the first signal terminal 2 and the first low-pass filter 20. Capacitor C2 is provided between the first low-pass filter 20 and the filter circuit 10. Capacitor C3 is provided between the filter circuit 10 and the second low-pass filter 30. Capacitor C4 is provided between the second low-pass filter 30 and the second signal terminal 3.

[0029] In this embodiment, a high-pass filter is formed by a filter circuit 10 and capacitors C2 and C3. Filter device 1 is a bandpass filter composed of filter circuit 10, a first low-pass filter 20, a second low-pass filter 30, and capacitors C2 and C3. Filter device 1 is configured to selectively pass signals with frequencies within a predetermined passband.

[0030] Next, refer to Figure 1 An example of the circuit structure of each of the filter circuit 10, the first low-pass filter 20, and the second low-pass filter 30 will be described. First, the circuit structure of the filter circuit 10 will be described. The filter circuit 10 includes inductors L11, L12, L13, and L14, and a capacitor C11. Inductors L11 to L14 each have a first end and a second end located on opposite sides of each other. Below, the first and second ends of the inductor L11 are represented by the reference numerals L11a and L11b, respectively; the first and second ends of the inductor L12 are represented by the reference numerals L12a and L12b, respectively; the first and second ends of the inductor L13 are represented by the reference numerals L13a and L13b, respectively; and the first and second ends of the inductor L14 are represented by the reference numerals L14a and L14b, respectively.

[0031] A first end L11a of the inductor L11 and a first end L12a of the inductor L12 are connected to each other. A second end L11b of the inductor L11 is connected to the capacitor C2. A second end L12b of the inductor L12 is connected to one end of the capacitor C11.

[0032] A first end L13a of the inductor L13 and a first end L14a of the inductor L14 are connected to each other. A second end L13b of the inductor L13 is connected to the other end of the capacitor C11. A second end L14b of the inductor L14 is connected to the capacitor C3.

[0033] Filter circuit 10 further includes acoustic wave elements 31 and 32 and an inductor L15. Each of acoustic wave elements 31 and 32 can be, for example, a bulk acoustic wave element or a surface acoustic wave element. One end of acoustic wave element 31 is connected to first end L11a of inductor L11 and first end L12a of inductor L12. One end of acoustic wave element 32 is connected to first end L13a of inductor L13 and first end L14a of inductor L14. The other end of each of acoustic wave elements 31 and 32 is connected to one end of inductor L15. The other end of inductor L15 is connected to ground.

[0034] Inductor L11 is configured between the first signal terminal 2 and the acoustic wave element 31. Inductor L12 is configured between the second signal terminal 3 and the acoustic wave element 31. Inductor L13 is configured between the first signal terminal 2 and the acoustic wave element 32. Inductor L14 is configured between the second signal terminal 3 and the acoustic wave element 32.

[0035] Elastic wave elements 31 and 32 are each electrically connected to the ground via inductor L15. In this application, the term "electrically connected" includes electrical connection via a metal conductor (including an inductor), but does not include connection via a capacitor. Since capacitors C1 and C2 are interposed between elastic wave element 31 and first signal terminal 2, elastic wave element 31 is not electrically connected to first signal terminal 2. Furthermore, since capacitors C3, C4, and C11 are interposed between elastic wave element 31 and second signal terminal 3, elastic wave element 31 is not electrically connected to second signal terminal 3. Furthermore, since capacitors C1, C2, and C11 are interposed between elastic wave element 32 and first signal terminal 2, elastic wave element 32 is not electrically connected to first signal terminal 2. Furthermore, since capacitors C3 and C4 are interposed between elastic wave element 32 and second signal terminal 3, elastic wave element 32 is not electrically connected to second signal terminal 3.

[0036] Inductors L11 to L15 , capacitor C11 , and elastic wave elements 31 and 32 are configured to form a high-pass filter.

[0037] Next, the circuit configuration of the first low-pass filter 20 will be described. The first low-pass filter 20 includes an inductor L21 and capacitors C21 and C22. One end of the inductor L21 is connected to the capacitor C1. The other end of the inductor L21 is connected to the capacitor C2.

[0038] The capacitor C21 is connected in parallel with the inductor L21. One end of the capacitor C22 is connected to the other end of the inductor L21. The other end of the capacitor C22 is connected to the ground.

[0039] Next, the circuit configuration of the second low-pass filter 30 will be described. The second low-pass filter 30 includes an inductor L31 and capacitors C31 and C32. One end of the inductor L31 is connected to the capacitor C3. The other end of the inductor L31 is connected to the capacitor C4.

[0040] The capacitor C31 is connected in parallel with the inductor L31. One end of the capacitor C32 is connected to one end of the inductor L31. The other end of the capacitor C32 is connected to the ground.

[0041] Next, the connection relationship between capacitors C1 to C4 is described. One end of capacitor C1 is connected to first signal terminal 2. The other end of capacitor C1 is connected to one end of inductor L21. One end of capacitor C2 is connected to the other end of inductor L21. The other end of capacitor C2 is connected to second end L11b of inductor L11.

[0042] One end of the capacitor C3 is connected to the second end L14b of the inductor L14. The other end of the capacitor C3 is connected to one end of the inductor L31. One end of the capacitor C4 is connected to the other end of the inductor L31. The other end of the capacitor C4 is connected to the second signal terminal 3.

[0043] Next, refer to Figures 2 to 4 Other structures of the filter device 1 will be described. Figure 2 It is a perspective view showing the filter device 1 . Figure 3 as well as Figure 4 It is a perspective view showing a first main body of the filter device 1 .

[0044] The filter device 1 of this embodiment includes a first body 50 and a second body 80 mounted on the first body 50. The first body 50 is composed of a laminate comprising multiple dielectric layers and multiple conductors (multiple conductor layers and multiple through-holes). The multiple dielectric layers are each made of a dielectric material. For example, low-temperature co-fired ceramic (LTCC) is used as the dielectric material.

[0045] The first body 50 includes at least one first element. The second body 80 includes at least one second element. The filter device 1 includes a circuit including at least one first element and at least one second element. In this embodiment, the first body 50 includes Figure 1 The inductors L11 to L15 and the capacitor C11 are shown as at least one first element. The second body 80 includes Figure 1 The elastic wave elements 31 and 32 shown in the figure serve as at least one second element. Filter device 1 includes a filter circuit 10 including inductors L11 to L15 , a capacitor C11 , and elastic wave elements 31 and 32 as the circuit.

[0046] The first body 50 further includes Figure 1 Inductors L21 and L31 and capacitors C1 to C4, C21, C22, C31, and C32 are shown. Inductors L11 to L15, L21, and L31, and capacitors C1 to C4, C11, C21, C22, C31, and C32 are located within first body 50, a laminate, and are constructed using multiple dielectric layers and multiple conductors. Elastic wave elements 31 and 32 are mounted on first body 50, a laminate.

[0047] The first body 50 has a first surface 50A and a second surface 50B located at opposite ends in the stacking direction T of the multiple dielectric layers; and four side surfaces 50C to 50F connecting the first surface 50A and the second surface 50B. Side surfaces 50C and 50D face opposite sides, and side surfaces 50E and 50F also face opposite sides. Side surfaces 50C to 50F are perpendicular to the first surface 50A and the second surface 50B.

[0048] Here, if Figures 2 to 4 As shown in FIG, the X, Y, and Z directions are defined. The X, Y, and Z directions are mutually orthogonal. In this embodiment, the Z direction is a direction parallel to the stacking direction T. Furthermore, the direction opposite to the X direction is referred to as the -X direction, the direction opposite to the Y direction is referred to as the -Y direction, and the direction opposite to the Z direction is referred to as the -Z direction. Furthermore, the expression "when viewed from a predetermined direction (e.g., the Z direction)" means observing the object from a separate position along the predetermined direction or a direction parallel to the predetermined direction.

[0049] like Figures 2 to 4 As shown, the first surface 50A is located at the Z-direction end of the first body 50. The first surface 50A is both the top surface of the first body 50 and the mounting surface for mounting the second body 80. The second surface 50B is located at the -Z-direction end of the first body 50. The second surface 50B is also the bottom surface of the first body 50. Figure 3 The first body 50 is shown as viewed from the first surface 50A side. Figure 4The first body 50 is shown as viewed from the second surface 50B side.

[0050] Side surface 50C is located at the -X end of first body 50. Side surface 50D is located at the X end of first body 50. Side surface 50E is located at the -Y end of first body 50. Side surface 50F is located at the Y end of first body 50.

[0051] The first body 50 further includes a plurality of electrodes 111, 112, 113, 114, 115, 116, 117, 118, and 119 disposed on the second surface 50B of the first body 50. Electrodes 111, 112, and 113 are arranged in this order along the X direction, closer to the side surface 50E than to the side surface 50F. Electrodes 115, 116, and 117 are arranged in this order along the -X direction, closer to the side surface 50F than to the side surface 50E.

[0052] Electrode 114 is arranged between electrode 113 and electrode 115. Electrode 118 is arranged between electrode 111 and electrode 117. Electrode 119 is arranged between electrode 112 and electrode 116. Electrode 119 is arranged substantially in the center of second surface 50B.

[0053] Electrode 114 corresponds to first signal terminal 2. Electrode 118 corresponds to second signal terminal 3. Therefore, first signal terminal 2 and second signal terminal 3 are provided on second surface 50B of first body 50. Electrodes 111, 112, 113, 115, 116, 117, and 119 are connected to grounding elements, respectively.

[0054] The first body 50 further includes a plurality of electrodes 121, 122, 123, and 124 disposed on the first surface 50A of the first body 50. Electrodes 121 and 122 are arranged in this order along the -X direction, closer to the side surface 50F than the side surface 50E. Electrodes 123 and 124 are arranged in this order along the -X direction, located forward of electrodes 121 and 122 in the Y direction.

[0055] The second body 80 further includes four electrodes 81, 82, 83, and 84. When the second body 80 is mounted on the first body 50, the four electrodes 81-84 are respectively opposed to the electrodes 121-124 of the first body 50. The four electrodes 81-84 are physically connected to the electrodes 121-124 via, for example, solder bumps 7.

[0056] The filter device 1 further includes a sealing portion (not shown) that seals the second body 80. The sealing portion covers the periphery of the second body 80 and at least a portion of the first surface 50A of the first body 50. The sealing portion may further cover the side surfaces 50C to 50F of the first body 50. The sealing portion is made of, for example, resin.

[0057] Next, refer to Figures 5A to 9 An example of the multiple dielectric layers, multiple conductor layers, and multiple through-holes that constitute the first body 50 will be described. In this example, the first body 50 includes eighteen stacked dielectric layers. Hereinafter, these eighteen dielectric layers will be referred to as the first through eighteenth dielectric layers, starting from the bottom. Reference numerals 51 to 68 denote the first through eighteenth dielectric layers.

[0058] exist Figures 5A to 8C In the figure, the multiple circles represent multiple through-holes. Multiple through-holes are formed in each of dielectric layers 51-68. Each of the multiple through-holes is formed by filling the holes for the through-holes with a conductive paste. Each of the multiple through-holes is connected to an electrode, a conductive layer, or another through-hole.

[0059] exist Figures 5A to 8C Specific through-holes among the plurality of through-holes are denoted by reference numerals. The connection relationship between each of the plurality of specific through-holes and an electrode, a conductor layer, or another through-hole will be described with respect to the state in which the first to eighteenth dielectric layers 51 to 68 are stacked.

[0060] Figure 5A : represents the pattern forming surface of the first dielectric layer 51. Electrodes 111 to 119 are formed on the pattern forming surface of the dielectric layer 51. Figure 5A The through hole denoted by reference numeral 51T7 is connected to the electrode 116. In the following description, the through hole denoted by reference numeral 51T7 is simply referred to as through hole 51T7. In addition, through holes denoted by reference numerals other than through hole 51T7 are also described in the same manner as through hole 51T7.

[0061] Figure 5B : represents the pattern forming surface of the second dielectric layer 52. A conductor layer 521 is formed on the pattern forming surface of the dielectric layer 52. The through hole 51T7 and Figure 5B The illustrated through-holes 52T7 a and 52T7 b are connected to the conductive layer 521 .

[0062] Figure 5C The pattern forming surface of the third dielectric layer 53 is shown. Conductive layers 531 and 532 are formed on the pattern forming surface of the dielectric layer 53. The through holes 52T7a and 52T7b are respectively connected to Figure 5C The through holes 53T7a, 53T7b are shown connected.

[0063] Figure 6A FIG. 5 shows the pattern forming surface of the fourth dielectric layer 54. Conductive layers 541, 542, 543, and 544 are formed on the pattern forming surface of the dielectric layer 54. Figure 6AThe through holes 54T1a and 54T2a are connected to the conductor layers 541 and 544 respectively. Figure 6A The through holes 54T7a, 54T7b are shown connected.

[0064] Figure 6B : shows the pattern forming surface of the fifth dielectric layer 55. Conductor layers 551, 552, 553, and 554 are formed on the pattern forming surface of the dielectric layer 55. Conductor layer 551 is connected to conductor layer 552. Conductor layer 553 is connected to conductor layer 554. Figure 6B In FIG. 5 , the boundary between the conductor layer 551 and the conductor layer 552 and the boundary between the conductor layer 553 and the conductor layer 554 are indicated by dotted lines.

[0065] Figure 6B The through holes 55T1b and 55T2b are connected to the conductor layers 552 and 554 respectively. The through holes 54T1a, 54T2a, 54T7a and 54T7b are connected to the conductor layers 552 and 554 respectively. Figure 6B The through holes 55T1a, 55T2a, 55T7a, and 55T7b are shown connected.

[0066] Figure 6C : shows the pattern forming surface of the sixth dielectric layer 56. Conductive layers 561, 562, 563, and 564 are formed on the pattern forming surface of the dielectric layer 56. The through hole 55T1a and Figure 6C The through hole 56T1a is shown to be connected to the conductor layer 562. The through hole 55T2a and Figure 6C The through hole 56T2a is connected to the conductor layer 564. The through holes 55T1b, 55T2b, 55T7a, and 55T7b are connected to the conductor layer 564. Figure 6C The vias 56T1b, 56T2b, 56T7a, 56T7b are shown connected.

[0067] Figure 7A The patterned surfaces of the seventh to thirteenth dielectric layers 57 to 63 are shown. Vias 56T1a, 56T1b, 56T2a, 56T2b, 56T7a, and 56T7b are connected to vias 57T1a, 57T1b, 57T2a, 57T2b, 57T7a, and 57T7b, respectively, formed in dielectric layer 57. Furthermore, in dielectric layers 57 to 63, vertically adjacent vias with the same reference numerals are connected to each other.

[0068] Figure 7B : shows the pattern forming surface of the fourteenth dielectric layer 64. A conductor layer 641 is formed on the pattern forming surface of the dielectric layer 64. The through holes 57T1a, 57T1b, 57T2a, 57T2b, 57T7a, and 57T7b formed in the dielectric layer 63 are connected to the respective Figure 7BThe through-holes 64T1a, 64T1b, 64T2a, 64T2b, 64T7a, 64T7b are shown connected.

[0069] Figure 7C The figure shows the patterned surface of the fifteenth dielectric layer 65. Conductive layers 651, 652, 653, and 654 for inductors are formed on the patterned surface of the dielectric layer 65. The conductive layer 651 has a first end and a second end located on opposite sides of the conductive layer 651 in its longitudinal direction. Figure 7C The illustrated through-hole 65T3 is connected to a portion near the first end of the conductor layer 651. The conductor layer 652 has a first end and a second end located on opposite sides of the conductor layer 652 in the longitudinal direction. Figure 7C The illustrated via 65T4 is connected to a portion of the conductive layer 652 near the first end.

[0070] The conductive layer 653 has a first end and a second end located on opposite sides of each other in the longitudinal direction of the conductive layer 653 . Figure 7C The illustrated through-hole 65T5 is connected to a portion near the first end of the conductor layer 653. The conductor layer 654 has a first end and a second end located on opposite sides of the conductor layer 654 in the longitudinal direction. Figure 7C The illustrated via 65T6 is connected to a portion of the conductive layer 654 near the first end.

[0071] Through holes 64T1a, 64T1b, 64T2a, 64T2b, 64T7a, and 64T7b are respectively Figure 7C The through holes 65T1a, 65T1b, 65T2a, 65T2b, 65T7a, 65T7b are shown connected.

[0072] Figure 8A The figure shows the patterned surface of the sixteenth dielectric layer 66. Conductive layers 661, 662, 663, and 664 for inductors are formed on the patterned surface of the dielectric layer 66. The conductive layer 661 has a first end and a second end located on opposite sides of the conductive layer 661 in its longitudinal direction. Figure 8A The illustrated through-hole 66T3 is connected to a portion near the first end of the conductor layer 661. The through-hole 65T3 is connected to a portion near the second end of the conductor layer 661. The conductor layer 662 has a first end and a second end located on opposite sides of the conductor layer 662 in its longitudinal direction. Figure 8A The illustrated via 66T4 is connected to a portion near the first end of the conductor layer 662. The illustrated via 65T4 is connected to a portion near the second end of the conductor layer 662.

[0073] The conductive layer 663 has a first end and a second end located on opposite sides of each other in the longitudinal direction of the conductive layer 663 . Figure 8AThe illustrated through-hole 66T5 is connected to a portion near the first end of the conductor layer 663. The through-hole 65T5 is connected to a portion near the second end of the conductor layer 663. The conductor layer 664 has a first end and a second end located on opposite sides of the conductor layer 664 in the longitudinal direction. Figure 8A The illustrated via 66T6 is connected to a portion near the first end of the conductor layer 664. The illustrated via 65T6 is connected to a portion near the second end of the conductor layer 664.

[0074] Through holes 65T1a, 65T1b, 65T2a, 65T2b, 65T7a, 65T7b are respectively Figure 8A The through-holes 66T1a, 66T1b, 66T2a, 66T2b, 66T7a, 66T7b are shown connected.

[0075] Figure 8B FIG. 1 shows the patterned surface of the seventeenth dielectric layer 67. Conductive layers 671, 672, 673, 674, 677, and 678 for inductors and conductive layers 675 and 676 are formed on the patterned surface of the dielectric layer 67.

[0076] The conductor layer 671 has a first end and a second end located on opposite sides of the longitudinal direction of the conductor layer 671. The conductor layer 672 has a first end and a second end located on opposite sides of the longitudinal direction of the conductor layer 672. The first end of the conductor layer 671 and the first end of the conductor layer 672 are connected to the conductor layer 675. Figure 8B In FIG. 6 , the boundary between the conductive layer 671 and the conductive layer 675 and the boundary between the conductive layer 672 and the conductive layer 675 are indicated by dotted lines. Figure 8B The via 67T3 shown is connected to the conductor layer 675.

[0077] The through hole 66T3 is connected to a portion near the second end of the conductor layer 671. The through hole 66T4 is connected to a portion near the second end of the conductor layer 672.

[0078] The conductor layer 673 has a first end and a second end located on opposite sides of the longitudinal direction of the conductor layer 673. The conductor layer 674 has a first end and a second end located on opposite sides of the longitudinal direction of the conductor layer 674. The first end of the conductor layer 673 and the first end of the conductor layer 674 are connected to the conductor layer 676. Figure 8B In FIG. 6 , the boundary between the conductor layer 673 and the conductor layer 676 and the boundary between the conductor layer 674 and the conductor layer 676 are indicated by dotted lines. Figure 8B Via 67T4 is shown connected to conductor layer 676 .

[0079] The through hole 66T5 is connected to a portion near the second end of the conductive layer 673. The through hole 66T6 is connected to a portion near the second end of the conductive layer 674.

[0080] The conductive layer 677 has a first end and a second end located on opposite sides of the longitudinal direction of the conductive layer 677. The through hole 66T1a is connected to a portion of the conductive layer 677 near the first end. The through hole 66T1b is connected to a portion of the conductive layer 677 near the second end.

[0081] The conductive layer 678 has a first end and a second end located on opposite sides of the longitudinal direction of the conductive layer 678. The through hole 66T2a is connected to a portion of the conductive layer 678 near the first end. The through hole 66T2b is connected to a portion of the conductive layer 678 near the second end.

[0082] Through holes 66T7a and 66T7b are respectively Figure 8B The through holes 67T7a, 67T7b are shown connected.

[0083] Figure 8C The pattern forming surface of the eighteenth dielectric layer 68 is shown. The through holes 67T3, 67T4, 67T7a, and 67T7b are respectively Figure 8C The through holes 68T3, 68T4, 68T7a, 68T7b are shown connected.

[0084] Figure 9 : This represents the surface of the eighteenth dielectric layer 68 opposite the pattern-formed surface. Hereinafter, the surface of the dielectric layer 68 opposite the pattern-formed surface is referred to as the electrode-formed surface of the dielectric layer 68. Electrodes 121, 122, 123, and 124 are formed on the electrode-formed surface of the dielectric layer 68. Vias 68T3, 68T4, 68T7a, and 68T7b are connected to electrodes 121, 122, 123, and 124, respectively.

[0085] The first body 50 is constructed by stacking the first to eighteenth dielectric layers 51 to 68 such that the pattern-formed surface of the first dielectric layer 51 becomes the second surface 50B of the first body 50 and the electrode-formed surface of the eighteenth dielectric layer 68 becomes the first surface 50A of the first body 50 .

[0086] Figures 5A to 8C Each of the plurality of through holes shown is connected to a conductor layer stacked in the stacking direction T or another through hole stacked in the stacking direction T when the first to eighteenth dielectric layers 51 to 68 are stacked. Figures 5A to 8C Among the plurality of through-holes shown, the through-holes located in the electrode or the conductor layer are connected to the electrode or the conductor layer.

[0087] Figure 10 1 shows the interior of the first body 50 formed by stacking the first to eighteenth dielectric layers 51 to 68. Figure 10 As shown, inside the first body 50, there are stacked Figures 5A to 9Multiple conductor layers and multiple through-holes are shown.

[0088] Next, Figure 1 The circuit components of the filter device 1 shown are similar to Figures 5A to 9 The corresponding relationship between the internal components of the first body 50 shown will be described.

[0089] First, the filter circuit 10 will be described. The inductor L11 is formed of the inductor conductive layers 651, 661, and 671 and the vias 65T3 and 66T3. The inductor L12 is formed of the inductor conductive layers 652, 662, and 672 and the vias 65T4 and 66T4.

[0090] The inductor L13 is formed of the inductor conductive layers 653, 663, and 673 and the vias 65T5 and 66T5. The inductor L14 is formed of the inductor conductive layers 654, 664, and 674 and the vias 65T6 and 66T6.

[0091] The inductor L15 is formed by the through-hole 51T7. The capacitor C11 is formed by the conductor layers 641, 652, and 653 and the dielectric layer 64 therebetween.

[0092] Next, the first low-pass filter 20 is described. The inductor L21 is formed by the inductor conductor layer 677, the conductor layer 562, and the vias 54T1a, 55T1a, 55T1b, 56T1a, 56T1b, 57T1a, 57T1b, 64T1a, 64T1b, 65T1a, 65T1b, 66T1a, and 66T1b.

[0093] Capacitor C21 is formed by conductor layers 541 and 551 and dielectric layer 54 therebetween. Capacitor C22 is formed by conductor layers 542 and 552 and dielectric layer 54 therebetween.

[0094] Next, the second low-pass filter 30 is described. The inductor L31 is formed by the inductor conductor layer 678, the conductor layer 564, and the vias 54T2a, 55T2a, 55T2b, 56T2a, 56T2b, 57T2a, 57T2b, 64T2a, 64T2b, 65T2a, 65T2b, 66T2a, and 66T2b.

[0095] Capacitor C31 is formed by conductor layers 544 and 553 and dielectric layer 54 therebetween. Capacitor C32 is formed by conductor layers 543 and 554 and dielectric layer 54 therebetween.

[0096] Next, capacitors C1 to C4 are described. Capacitor C1 is composed of conductor layers 531 and 541 and dielectric layer 53 between them. Capacitor C2 is composed of conductor layers 551 and 561 and dielectric layer 55 between them. Capacitor C3 is composed of conductor layers 553 and 563 and dielectric layer 55 between them. Capacitor C4 is composed of conductor layers 532 and 544 and dielectric layer 53 between them.

[0097] Next, features related to acoustic wave elements 31 and 32 are described. One end of acoustic wave element 31 is connected to conductive layer 671, which constitutes inductor L11, and conductive layer 672, which constitutes inductor L12, via conductive layer 675, via vias 67T3 and 68T3, and electrodes 121 and 81. The other end of acoustic wave element 31 is connected to via 51T7, which constitutes inductor L15, via conductive layer 521, via vias 52T7a, 53T7a, 54T7a, 55T7a, 56T7a, 57T7a, 64T7a, 65T7a, 66T7a, 67T7a, and 68T7a, and electrodes 123 and 83.

[0098] Here, a columnar structure formed by connecting a plurality of through-holes in series is referred to as a columnar conductor. The columnar conductor extends in a direction parallel to the stacking direction T. Figure 10 The columnar conductor T7a shown is formed by vias 52T7a, 53T7a, 54T7a, 55T7a, 56T7a, 57T7a, 64T7a, 65T7a, 66T7a, 67T7a, and 68T7a. The other end of acoustic wave element 31 is connected to via 51T7 forming inductor L15 via conductive layer 521, columnar conductor T7a, and electrodes 123 and 83.

[0099] One end of acoustic wave element 32 is connected to conductive layer 673 forming inductor L13 and conductive layer 674 forming inductor L14 via conductive layer 676 , vias 67T4 and 68T4 , and electrodes 122 and 82 . Figure 10 The columnar conductor T7b shown is formed by vias 52T7b, 53T7b, 54T7b, 55T7b, 56T7b, 57T7b, 64T7b, 65T7b, 66T7b, 67T7b, and 68T7b. The other end of acoustic wave element 32 is connected to via 51T7 forming inductor L15 via conductive layer 521, columnar conductor T7b, and electrodes 124 and 84.

[0100] Next, the functions and effects of the filter device 1 of this embodiment will be described. In this embodiment, capacitors C1 and C2 are provided in the first path 5 connecting the first signal terminal 2 and the filter circuit 10, and capacitors C3 and C4 are provided in the second path 6 connecting the second signal terminal 3 and the filter circuit 10. Thus, according to this embodiment, low-frequency signals passing through the first path 5 and the second path 6 can be removed. As a result, according to this embodiment, low-frequency noise can be prevented from being superimposed on the signal to be extracted by the filter device 1.

[0101] Furthermore, in this embodiment, each of the elastic wave elements 31 and 32 is electrically connected to the ground via the inductor L15. In this embodiment, specifically, each of the elastic wave elements 31 and 32 is electrically connected to the ground only via the path through the inductor L15. Furthermore, in this embodiment, each of the elastic wave elements 31 and 32 is not electrically connected to the first signal terminal 2 or the second signal terminal 3. In this embodiment, specifically, the first signal terminal 2 and the second signal terminal 3 are not electrically connected to each other, and the electrode 114 corresponding to the first signal terminal 2 and the electrode 118 corresponding to the second signal terminal 3 are not electrically connected to other electrodes. Therefore, in this embodiment, even if electrostatic discharge occurs near the filter device 1 and a voltage is applied to the electrodes 111 to 119, current does not flow through the elastic wave elements 31 and 32.

[0102] Therefore, according to this embodiment, the reliability of the filter device 1 can be improved.

[0103] In addition, in this embodiment, the first low-pass filter 20 is provided in the first path 5, and the second low-pass filter 30 is provided in the second path 6. When a signal is input to the filter circuit 10, in addition to the signal, higher harmonics having a higher frequency than the signal are output from the filter circuit 10. According to this embodiment, the first low-pass filter 20 and the second low-pass filter 30 can remove the higher harmonics. Therefore, according to this embodiment, the reliability of the filter device 1 can also be improved.

[0104] Furthermore, in this embodiment, capacitor C2 is connected in series with inductor L11 of filter circuit 10. Capacitor C2 and inductor L11 form a series LC resonator. Generally speaking, filter circuits using elastic wave elements are suitable for achieving passband attenuation characteristics that change dramatically in the frequency range close to the passband. However, filter circuits using elastic wave elements have the problem of difficulty achieving sufficient bandwidth. To address this issue, according to this embodiment, the series LC resonator formed by capacitor C2 and inductor L11 can increase the passband.

[0105] Similarly, capacitor C3 is connected in series with inductor L14 of filter circuit 10. Capacitor C3 and inductor L14 form a series LC resonator. According to this embodiment, the passband can be widened by the series LC resonator formed by capacitor C3 and inductor L14.

[0106] As described above, in this embodiment, capacitors C2 and C3 have the functions of preventing low-frequency noise from being superimposed on the signal to be extracted by filter device 1 , preventing static electricity-induced current from flowing through elastic wave elements 31 and 32 , and widening the passband.

[0107] Furthermore, the present invention is not limited to the above-described embodiments and can be modified in various ways. For example, the filter device of the present invention is not limited to bandpass filters but can be applied to other filter devices such as low-pass filters and high-pass filters, as well as electronic devices including multiple resonators, such as splitters that separate multiple signals of different frequency bands.

[0108] Furthermore, second body 80 may include only one elastic wave element or three or more. Furthermore, second body 80 may include any passive element, such as a capacitor, in addition to elastic wave elements 31 and 32. In this case, the passive element may be connected to elastic wave element 31 or 32. Furthermore, second body 80 may include any active element containing a semiconductor, such as a high-frequency switch, in place of elastic wave elements 31 and 32, or in addition to elastic wave elements 31 and 32.

[0109] Furthermore, two or more low-pass filters may be provided in each of the first path 5 and the second path 6. Furthermore, three or more capacitors may be provided in each of the first path 5 and the second path 6.

[0110] As described above, the filter device of the present invention comprises: a first body including a first element; a second body mounted on the first body and including a second element; a filter circuit including a first element and a second element; a first capacitor; and a second capacitor. The first body further includes a first signal terminal and a second signal terminal. The filter circuit is arranged between the first signal terminal and the second signal terminal in terms of circuit structure. The first capacitor is arranged in a first path connecting the first signal terminal to the filter circuit. The second capacitor is arranged in a second path connecting the second signal terminal to the filter circuit.

[0111] In the filter device of the present invention, the first capacitor and the second capacitor may be included in the first body.

[0112] In the filter device of the present invention, the filter circuit may constitute a high-pass filter. The second element may be connected to the ground.

[0113] In addition, the filter device of the present invention may further include a first low-pass filter disposed in the first path. The first capacitor may be disposed between the filter circuit and the first low-pass filter in terms of circuit structure. The filter device of the present invention may further include a second low-pass filter disposed in the second path. The second capacitor may be disposed between the filter circuit and the second low-pass filter in terms of circuit structure.

[0114] In the filter device of the present invention, the first element may be an inductor. The inductor may be connected in series with one of the first capacitor and the second capacitor. The inductor and the capacitor may form an LC resonator.

[0115] Furthermore, in the filter device of the present invention, the second element may be an elastic wave element.

[0116] It is clear from the above description that the present invention can be implemented in various forms and modifications. Therefore, within the scope of the equivalents of the claims, the present invention can be implemented in forms other than the above-described embodiment.

Claims

1. A filter device, characterized in that: have: a first body comprising a first element; a second body mounted on the first body and comprising a second element; a filter circuit comprising the first element and the second element; a first capacitor; as well as The second capacitor, The first body further includes a first signal terminal and a second signal terminal, The filter circuit is arranged between the first signal terminal and the second signal terminal in terms of circuit structure. The first capacitor is provided in a first path connecting the first signal terminal and the filter circuit. The second capacitor is provided in a second path connecting the second signal terminal and the filter circuit.

2. The filter device according to claim 1, wherein The first capacitor and the second capacitor are included in the first body.

3. The filter device according to claim 1, wherein The filter circuit forms a high-pass filter.

4. The filter device according to claim 3, characterized in that The second element is connected to the grounding element.

5. The filter device according to claim 1, wherein The device further includes a first low-pass filter provided in the first path.

6. The filter device according to claim 5, characterized in that The first capacitor is arranged between the filter circuit and the first low-pass filter in terms of circuit structure.

7. The filter device according to claim 5, characterized in that A second low-pass filter is further provided in the second path.

8. The filter device according to claim 7, characterized in that The second capacitor is arranged between the filter circuit and the second low-pass filter in terms of circuit structure.

9. The filter device according to claim 1, wherein The first element is an inductor.

10. The filter device according to claim 9, characterized in that The inductor is connected in series with one of the first capacitor and the second capacitor. The inductor and the one capacitor form an LC resonator.

11. The filter device according to any one of claims 1 to 10, characterized in that The second element is an elastic wave element.

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