Electronic component, acoustic wave device, filter, and multiplexer

Abstract

To provide an electronic component capable of restraining occurrence of electrical connection failure between via wiring and a frame body.SOLUTION: An acoustic wave device 100 includes a substrate 10, an acoustic wave element 50 provided on an upper surface 11 of the substrate 10, via wiring 23 that is embedded in a through-hole 24 provided from the upper surface 11 to a lower surface 12 of the substrate 10, a conductive film 26 provided in contact with the via wiring 23 on the upper surface 11 of the substrate 10, a frame body 30 that is provided on the upper surface 11 of the substrate 10 so as to surround the acoustic wave element 50 in plan view, has a gap 33 that is provided between the frame 30 and the conductive film 26 so as to overlap the via wiring 23 in plan view, and is in contact with the conductive film 26, and a lid body 40 that is provided on the frame body 30 with a gap 28 interposed between the lid body 40 and the substrate 10, and seals the acoustic wave element 50 in the gap 28.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to electronic components, acoustic wave devices, filters, and multiplexers. [Background technology]

[0002] It is known that a frame is provided to surround a functional element provided on a substrate, and a lid is provided on the frame, thereby sealing the functional element in the gap between the substrate and the lid. It is known that the frame is connected to a via wiring provided on the substrate in order to supply a ground potential to the frame and the lid (for example, Patent Document 1). Also, a configuration is known in which a protruding electrode is provided on the via wiring of the lower substrate, and the functional element of the upper substrate is electrically connected to the via wiring of the lower substrate (for example, Patent Document 2).

[0003] In order to prevent the destruction of the capacitor due to the deformation of the via wiring, it is known to provide a gap on the via wiring and provide the capacitor outside the gap (for example, Patent Document 3). In order to prevent the damage of the substrate due to the via wiring, it is known to fill the inside of the via wiring in the through hole with the same material as the substrate (for example, Patent Document 4), to provide a gap inside the via wiring (for example, Patent Document 5), and to fill the outside of the via wiring with a filler (for example, Patent Document 6). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2022-44323 [Patent Document 2] Patent Publication No. 2022-72241 [Patent Document 3] JP 2010-182708 A [Patent Document 4] JP 2012-74640 A [Patent Document 5] JP 2016-32087 A [Patent Document 6] JP 2014-229661 A Summary of the Invention [Problem to be solved by the invention]

[0005] When a frame or a protruding electrode is provided on a via wiring, thermal expansion and contraction of the via wiring may cause poor electrical connection between the via wiring and the frame or the protruding electrode.

[0006] The present invention has been made in consideration of the above problems, and has an object to suppress the occurrence of poor electrical connection between via wiring and a frame or protruding electrode. [Means for solving the problem]

[0007] The present invention is an electronic component comprising a substrate, a functional element provided on a first surface of the substrate, a via wiring embedded in a through hole provided from the first surface of the substrate to a second surface opposite the first surface, a conductive film provided on the first surface of the substrate in contact with the via wiring, a frame body provided on the first surface of the substrate and surrounding the functional element in a planar view, having a first gap between the frame body and the conductive film that overlaps the via wiring in a planar view and in contact with the conductive film, and a lid body provided on the frame body with a second gap between the frame body and the substrate, and sealing the functional element within the second gap.

[0008] In the above configuration, the configuration can include another conductive film provided on the second surface of the substrate in contact with the via wiring, and a metal film provided on the second surface of the substrate, having a third gap between the other conductive film and the metal film overlapping the via wiring in a planar view, and in contact with the other conductive film.

[0009] In the above configuration, the functional element may include a piezoelectric layer provided on the first surface of the substrate, with its lower surface directly or indirectly in contact with the first surface and spaced apart from the via wiring, the functional element being an elastic wave element provided on the piezoelectric layer, and the via wiring being provided outside the area where the piezoelectric layer and the substrate overlap.

[0010] In the above configuration, the frame body can have a ring-shaped first portion and a second portion extending from the first portion toward the inside of the ring and overlapping the via wiring in a planar view, the first void is provided in the second portion from above the via wiring toward the inside of the ring and connected to the second gap, and the frame body can be configured to be in contact with the conductive film in three directions around the first gap.

[0011] In the above configuration, in the region where the via wiring and the frame body overlap in a planar view, the minimum height of the first gap between the frame body and the conductive film can be configured to be 0.01 times or more the thickness of the substrate.

[0012] The present invention is an acoustic wave device comprising: a substrate; a piezoelectric layer provided on a first surface of the substrate, the lower surface of which is in direct or indirect contact with the first surface; an acoustic wave element provided on the piezoelectric layer; a via wiring embedded in a through hole provided from the first surface to a second surface of the substrate opposite the first surface; a conductive film provided in contact with the via wiring on the first surface of the substrate; and a protruding electrode provided on the first surface of the substrate overlapping the via wiring in a planar view, having a gap between the conductive film and the protruding electrode that overlaps the via wiring in a planar view, and in contact with the conductive film.

[0013] In the above configuration, the gap may be provided so as to penetrate the protruding electrode, and the protruding electrode may be in contact with the conductive film on both sides of the gap.

[0014] In the above configuration, the configuration can include another substrate provided on the first surface of the substrate with a gap therebetween, another elastic wave element provided on the other substrate, and another via wiring provided through the other substrate and connected between the other elastic wave element and the protruding electrode.

[0015] The present invention is a filter including the above-described electronic component or the above-described acoustic wave device.

[0016] The present invention is a multiplexer comprising the filter described above. Effect of the Invention

[0017] According to the present invention, it is possible to suppress the occurrence of poor electrical connection between the via wiring and the frame or the protruding electrode. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a cross-sectional view of an acoustic wave device in accordance with a first embodiment. [Diagram 2] FIG. 2(a) is a plan view of the acoustic wave element in the first embodiment, and FIG. 2(b) is a cross-sectional view of another example of the acoustic wave element. [Diagram 3] 3(a) is a plan view of the vicinity of the terminal in the first embodiment as viewed from the -Z direction, FIG. 3(b) is a cross-sectional view taken along line AA in FIG. 3(a), and FIG. 3(c) is a cross-sectional view taken along line BB in FIG. 3(a). [Figure 4] FIG. 4 is a plan view showing a frame, a piezoelectric layer, and via wiring in the first embodiment. [Diagram 5] 5(a) is a plan view of the vicinity of the second portion of the frame body in Example 1 as viewed from the +Z direction, FIG. 5(b) is a cross-sectional view taken along line AA in FIG. 5(a), and FIG. 5(c) is a cross-sectional view taken along line BB in FIG. 5(a). [Figure 6] 6(a) to 6(c) are cross-sectional views (part 1) illustrating a method for manufacturing the acoustic wave device in accordance with the first embodiment. [Figure 7] 7(a) to 7(c) are cross-sectional views (part 2) illustrating a method for manufacturing the acoustic wave device in accordance with the first embodiment. [Figure 8] 8(a) to 8(c) are cross-sectional views (part 1) showing a method for forming a frame in the first embodiment. [Figure 9] 9(a) and 9(b) are cross-sectional views (part 2) showing a method for forming the frame in the first embodiment. [Figure 10] 10(a) to 10(d) are cross-sectional views showing a method for forming a conductive film and a terminal in the first embodiment. [Figure 11] FIG. 11 is a cross-sectional view of an acoustic wave device according to a comparative example. [Figure 12] 12A and 12B are cross-sectional views illustrating a problem that occurs in an acoustic wave device according to a comparative example. [Figure 13] FIG. 13 is a cross-sectional view illustrating the effect of the acoustic wave device in accordance with the first embodiment. [Figure 14] 14(a) and 14(b) are cross-sectional views of the vicinity of via wiring in Modifications 1 and 2 of the first embodiment. [Figure 15] FIG. 15(a) is an exploded perspective view of the model used in the simulation, and FIG. 15(b) is a cross-sectional view of the model used in the simulation. [Figure 16] FIG. 16 shows the results of a simulation of the amount of thermal expansion of a via wiring. [Figure 17] FIG. 17 is a cross-sectional view of an acoustic wave device in accordance with the second embodiment. [Figure 18] 18(a) is a plan view of the vicinity of the via wiring in Example 2 as viewed from the +Z direction, FIG. 18(b) is a cross-sectional view taken along line AA in FIG. 18(a), and FIG. 18(c) is a cross-sectional view taken along line BB in FIG. 18(a). [Figure 19] 19(a) to 19(d) are cross-sectional views showing a method of forming a bump in a modified example of the second embodiment. [Figure 20] FIG. 20 is a circuit diagram of a filter in accordance with the third embodiment. [Figure 21] FIG. 21 is a circuit diagram of a duplexer in accordance with the fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the embodiment, an acoustic wave device will be described as an example of an electronic component. EXAMPLES

[0020] Fig. 1 is a cross-sectional view of an acoustic wave device 100 in accordance with a first embodiment. Directions parallel to an upper surface 11 of a substrate 10 and perpendicular to each other are defined as an X direction and a Y direction. The thickness direction of the substrate 10 is defined as a Z direction. Fig. 1 shows a schematic cross-section of the acoustic wave device 100 in accordance with a first embodiment (the same applies to the following similar figures).

[0021] As shown in FIG. 1, in the acoustic wave device 100 according to the first embodiment, a piezoelectric layer 20 is bonded to an upper surface 11 of a substrate 10. The substrate 10 is, for example, a sapphire substrate, an alumina substrate, a spinel substrate, a quartz substrate, a crystal substrate, or a silicon substrate, and has a thickness of 50 μm to 300 μm. The sapphire substrate is a substrate mainly composed of single crystal Al2O3, the alumina substrate is a substrate mainly composed of polycrystalline Al2O3, and the spinel substrate is a substrate mainly composed of single crystal or polycrystalline MgAl2O4. The quartz substrate is a substrate mainly composed of amorphous SiO2, the crystal substrate is a substrate mainly composed of single crystal SiO2, and the silicon substrate is a substrate mainly composed of single crystal or polycrystalline Si. The piezoelectric layer 20 is, for example, a single crystal lithium tantalate layer or a single crystal lithium niobate layer, and has a thickness of 0.5 μm to 30 μm. The thickness of the piezoelectric layer 20 is, for example, smaller than the wavelength of the main mode acoustic wave (e.g., surface acoustic wave) excited by the acoustic wave element 50. An insulating layer such as silicon oxide, aluminum oxide, and / or aluminum nitride may be provided between the substrate 10 and the piezoelectric layer 20. In this manner, the lower surface 19 of the piezoelectric layer 20 directly or indirectly contacts (is bonded to) the upper surface 11 of the substrate 10. The entire lower surface 19 of the piezoelectric layer 20 directly or indirectly contacts (is bonded to) the upper surface 11 of the substrate 10.

[0022] An acoustic wave element 50 is provided on the upper surface 18 of the piezoelectric layer 20. FIG. 2(a) is a plan view of the acoustic wave element 50 in the first embodiment. As shown in FIG. 2(a), the acoustic wave element 50 is a surface acoustic wave resonator. An IDT (Interdigital Transducer) 51 and a reflector 52 are provided on the upper surface 18 of the piezoelectric layer 20. The IDT 51 has a pair of opposing comb electrodes 53. The comb electrode 53 has a plurality of electrode fingers 54 and a bus bar 55 to which the plurality of electrode fingers 54 are connected. The reflector 52 is provided on both sides of the IDT 51. The plurality of electrode fingers 54 excites a surface acoustic wave in the piezoelectric layer 20. The pitch of the electrode fingers 54 of one of the pair of comb electrodes 53 is approximately the wavelength λ of the acoustic wave. The double of the pitch D of the plurality of electrode fingers 54 is approximately the wavelength λ of the acoustic wave. The IDT 51 and the reflector 52 are formed of a metal film such as aluminum, copper, or molybdenum. A protective film or a temperature compensation film covering the IDT 51 and the reflector 52 may be provided on the upper surface of the piezoelectric layer 20. The comb electrode 53 may have dummy electrode fingers.

[0023] FIG. 2(b) is a cross-sectional view of another example of the acoustic wave element 50. As shown in FIG. 2(b), the acoustic wave element 50 may be a piezoelectric thin film resonator. A piezoelectric layer 62 is provided on a substrate 10, and a lower electrode 61 and an upper electrode 63 are provided to sandwich the piezoelectric layer 62. A gap 64 is formed between the lower electrode 61 and the substrate 10. A region where the lower electrode 61 and the upper electrode 63 face each other with at least a part of the piezoelectric layer 62 sandwiched therebetween is a resonance region 65. In the resonance region 65, the lower electrode 61 and the upper electrode 63 excite an acoustic wave in the piezoelectric layer 62. The lower electrode 61 and the upper electrode 63 are metal films including, for example, a ruthenium film. The piezoelectric layer 62 is, for example, an aluminum nitride layer, a zinc oxide layer, a single crystal lithium tantalate layer, or a single crystal lithium niobate layer. An acoustic reflection film that reflects the acoustic wave may be provided instead of the gap 64.

[0024] 1, a conductive film 21 and a terminal 22 are provided overlapping on a lower surface 12 of a substrate 10. The terminal 22 is a foot pad for electrically connecting the acoustic wave element 50 to the outside. A via wiring 23 is provided by being embedded in a through hole 24 that penetrates the substrate 10 from the upper surface 11 to the lower surface 12. The conductive film 21 is in contact with the via wiring 23. The conductive film 21 has a thickness of, for example, 0.3 μm to 0.5 μm.

[0025] FIG. 3(a) is a plan view of the vicinity of the terminal 22 in the first embodiment as viewed from the -Z direction, FIG. 3(b) is an AA cross-sectional view of FIG. 3(a), and FIG. 3(c) is a BB cross-sectional view of FIG. 3(a). In FIG. 3(a), the portion where the terminal 22 contacts the conductive film 21 is hatched. As shown in FIG. 3(a) to FIG. 3(c), the conductive film 21 is larger than the via wiring 23 in a plan view and completely covers the via wiring 23. The terminal 22 has a gap 27 between the conductive film 21 and the terminal 22, which overlaps with the via wiring 23 in a plan view. The gap 27 is larger than the via wiring 23 in a plan view. The terminal 22 contacts the conductive film 21 around the gap 27. For example, the gap 27 is a tunnel-shaped gap that penetrates the terminal 22 in the Y direction. The terminal 22 contacts the conductive film 21 on both sides of the gap 27 in the X direction.

[0026] The gap 27 is not limited to being provided in a tunnel shape penetrating the terminal 22, but may be provided without penetrating the terminal 22 as shown in Figs. 5(a) to 5(c) described later.

[0027] 1, conductive film 26 is provided on upper surface 11 of substrate 10 in contact with via wiring 23. Conductive film 26 has a thickness of, for example, 0.3 μm to 0.5 μm. Acoustic wave element 50 is electrically connected to terminal 22 via wiring 25, conductive film 26, via wiring 23, and conductive film 21. Conductive film 21, terminal 22, via wiring 23, wiring 25, and conductive film 26 are metal layers containing, for example, titanium, copper, aluminum, platinum, nickel, and / or gold. Conductive film 21, terminal 22, via wiring 23, wiring 25, and conductive film 26 may be a single-layer metal layer or a laminated metal layer in which multiple layers are laminated.

[0028] The piezoelectric layer 20 is not provided in the peripheral region of the substrate 10. A frame body 30 is provided on the upper surface 11 of the substrate 10 in the peripheral region of the substrate 10. FIG. 4 is a plan view showing the frame body 30, the piezoelectric layer 20, and the via wiring 23 in the first embodiment. In FIG. 4, the shape of the piezoelectric layer 20 is simplified and the piezoelectric layer 20 and the frame body 30 are hatched for clarity of the drawing. As shown in FIGS. 1 and 4, the frame body 30 is provided on the upper surface 11 of the substrate 10 so as to surround the piezoelectric layer 20 in a plan view. The frame body 30 is provided away from the piezoelectric layer 20. The frame body 30 has a first annular portion 31 along the peripheral edge of the substrate 10 and a second portion 32 provided from the first portion 31 toward the inside of the annular shape and overlapping the via wiring 23 in a plan view. The width of the second portion 32 is larger than the diameter of the via wiring 23 on the upper surface 11 of the substrate 10.

[0029] 5(a) is a plan view of the vicinity of the second portion 32 of the frame body 30 in the first embodiment as viewed from the +Z direction, FIG. 5(b) is an AA cross-sectional view of FIG. 5(a), and FIG. 5(c) is a BB cross-sectional view of FIG. 5(a). In FIG. 5(a), the portion where the second portion 32 of the frame body 30 and the conductive film 26 are in contact with each other are hatched. As shown in FIG. 5(a) to FIG. 5(c), the conductive film 26, which is larger than the via wiring 23 in a plan view and covers and contacts the via wiring 23, is provided on the upper surface 11 of the substrate 10. The second portion 32 has a gap 33 between the conductive film 26 and the second portion 32, which overlaps with the via wiring 23 in a plan view. The gap 33 is larger than the via wiring 23 in a plan view. The second portion 32 is in contact with the conductive film 26 around the gap 33. For example, the gap 33 is formed from above the via wiring 23 toward the inside (+X direction) of the annular first portion 31, and the tip in the +X direction is open. The second portion 32 contacts the conductive film 26 in front of the tip on the -X direction side of the gap 33 and on both sides of the gap 33 in the Y direction. The frame body 30 is a metal layer containing, for example, copper, kovar, gold, aluminum, and / or tungsten. The frame body 30 may be a single layer, or may be a laminate of multiple layers. The height of the frame body 30 is, for example, about 15 μm to 30 μm. The width of the first portion 31 of the frame body 30 is, for example, about 10 μm to 40 μm.

[0030] 1, a lid 40 is provided on a frame 30 such that a gap 28 is formed between the frame 30 and the substrate 10. The acoustic wave element 50 is sealed in the gap 28 by the frame 30 and the lid 40. The lid 40 is a metal layer containing, for example, an iron alloy such as kovar, 42 alloy, or stainless steel, nickel, copper, nickel silver, or an aluminum alloy such as duralumin. Since the lid 40 is made of metal, heat generated from the acoustic wave element 50 can be dissipated to the lid 40.

[0031] The frame body 30 is electrically connected to the ground terminal 22 through the conductive film 26, the via wiring 23, and the conductive film 21 by the second portion 32 coming into contact with the conductive film 26. This allows a ground potential to be supplied to the frame body 30 and the lid body 40, and a shielding effect can be imparted to the frame body 30 and the lid body 40. Furthermore, since heat generated from the acoustic wave element 50 is dissipated to the lid body 40, by connecting the frame body 30 to the terminal 22 through the via wiring 23, the heat dissipated to the lid body 40 is transmitted to the terminal 22, improving the heat dissipation effect. Note that the frame body 30 and the lid body 40 are not electrically connected to the acoustic wave element 50 on the substrate 10.

[0032] [Manufacturing method] 6(a) to 7(c) are cross-sectional views showing a manufacturing method of the acoustic wave device 100 according to the first embodiment. As shown in FIG. 6(a), a via hole is formed on the upper surface 11 of the substrate 10 by irradiating the upper surface 11 with, for example, a laser beam, and a metal layer such as copper is formed in the via hole by, for example, an electrolytic plating method. After that, the metal layer is planarized by, for example, a chemical mechanical polishing (CMP) method so that the upper surface 11 of the substrate 10 is exposed. As a result, a via wiring 23 is formed in the substrate 10. Note that at this stage, the via wiring 23 does not penetrate the substrate 10.

[0033] As shown in Fig. 6(b), a piezoelectric substrate is bonded to an upper surface 11 of a substrate 10 at room temperature using, for example, a surface activation method. The substrate 10 and the piezoelectric substrate may be bonded directly via an amorphous layer of a few nm, or indirectly via an insulating layer. The upper surface of the piezoelectric substrate is then polished using, for example, a CMP method to form a piezoelectric layer 20 of a desired thickness. Next, an acoustic wave element 50 is formed on an upper surface 18 of the piezoelectric layer 20 using, for example, a photolithography method and an etching method.

[0034] As shown in FIG. 6(c), the piezoelectric layer 20 is removed from the peripheral region of the acoustic wave device, for example, by etching. This exposes the via wiring 23. Next, a conductive film 26 is formed on the upper surface 11 of the substrate 10 to cover the via wiring 23. The conductive film 26 is formed by, for example, forming a film by sputtering or vapor deposition, and then forming a desired shape by photolithography and etching. The conductive film 26 may be formed by lift-off. Next, wiring 25 to be connected to the acoustic wave element 50 is formed. The wiring 25 is formed by, for example, forming a film by sputtering or vapor deposition, and then forming a desired shape by photolithography and etching. The wiring 25 may be formed by lift-off.

[0035] 7(a), a frame 30 is formed on the upper surface 11 of the substrate 10 so as to surround the piezoelectric layer 20. The formation of the frame 30 will be described in detail below.

[0036] 8(a) to 9(b) are cross-sectional views showing a method for forming the frame body 30 in Example 1. As shown in FIG. 8(a), at least a resist film 70 is formed in a location where the gap 33 between the second portion 32 of the frame body 30 and the conductive film 26 is to be formed. The resist film 70 is formed by applying a resist, exposing it to light, and developing it. Next, a metal seed layer 71 is formed on the upper surface 11 of the substrate 10 by using, for example, a sputtering method. The metal seed layer 71 is formed to cover the resist film 70.

[0037] As shown in FIG. 8(b), a plating resist is applied to the upper surface 11 of the substrate 10, covering the resist film 70, and then patterned to form a plating resist film 72 having an opening 73 where the frame 30 is to be formed.

[0038] 8(c), the frame body 30 is formed by, for example, electrolytic plating using the plating resist film 72 as a mask. A part of the second portion 32 of the frame body 30 is formed on the resist film .

[0039] 9(a), the plating resist film 72 is removed by, for example, wet etching. Then, the metal seed layer 71 is removed by etching using the frame 30 as a mask. As a result, the metal seed layer 71 on the resist film 70 is removed.

[0040] 9(b), the resist film 70 is removed by, for example, wet etching. As a result, a gap 33 is formed between the second portion 32 of the frame body 30 and the conductive film 26 in the region overlapping with the via wiring 23.

[0041] 7(b), after the frame 30 is formed, the lid 40 is bonded to the frame 30. As a result, the acoustic wave element 50 is sealed in the gap 28 between the substrate 10 and the lid 40.

[0042] 7(c), the lower surface 12 of the substrate 10 is polished, for example, by CMP. As a result, the via wirings 23 are exposed from the lower surface 12 of the substrate 10. Next, a conductive film 21 is formed on the lower surface 12 of the substrate 10 to cover the via wirings 23, and terminals 22 are formed on the conductive film 21. The formation of the conductive film 21 and the terminals 22 will be described in detail below.

[0043] 10(a) to 10(d) are cross-sectional views showing a method for forming the conductive film 21 and the terminal 22 in Example 1. The steps shown in FIG. 10(a) to FIG. 10(d) may be performed after forming a protective film covering the frame 30 and the lid 40 on the upper surface 11 of the substrate 10. As shown in FIG. 10(a), the conductive film 21 is formed on the lower surface 12 of the substrate 10. The conductive film 21 is formed by, for example, a sputtering method or a vapor deposition method. Next, a resist film 75 is formed at a position where the gap 27 between the terminal 22 and the conductive film 21 should be formed. In addition, a plating resist film 76 having an opening 77 is formed at a position where the terminal 22 should be formed.

[0044] 10(b), the terminals 22 are formed by, for example, electrolytic plating using the plating resist film 76 as a mask.

[0045] 10(c), the plating resist film 76 and the resist film 75 are removed by, for example, wet etching. By removing the resist film 75, a gap 27 is formed between the terminal 22 and the conductive film 21 in the region overlapping with the via wiring 23.

[0046] 10(d), the conductive film 21 is removed by etching using the terminals 22 as a mask. In this manner, the conductive film 21 and the terminals 22 are formed.

[0047] [Comparative Example] FIG. 11 is a cross-sectional view of an acoustic wave device 500 according to a comparative example. As shown in FIG. 11, in the acoustic wave device 500 according to the comparative example, the conductive film 26 in contact with the via wiring 23 is not provided on the upper surface 11 of the substrate 10, and the second portion 32 of the frame 30 is provided in contact with the via wiring 23. Therefore, in the region where the second portion 32 and the via wiring 23 overlap in a plan view, no gap is formed between the second portion 32 and the via wiring 23. In addition, the conductive film 21 in contact with the via wiring 23 is not provided on the lower surface 12 of the substrate 10, and the terminal 22 is provided in contact with the via wiring 23. Therefore, in the region where the terminal 22 and the via wiring 23 overlap in a plan view, no gap is formed between the terminal 22 and the via wiring 23. The other configurations are the same as those of the first embodiment, and therefore description thereof will be omitted.

[0048] 12(a) and 12(b) are cross-sectional views for explaining a problem that occurs in the acoustic wave device 500 according to the comparative example. As shown in FIG. 12(a), when the acoustic wave device 500 is mounted on a circuit board by soldering, for example, the temperature rises, and the components such as the via wiring 23, the frame 30, and the terminal 22 thermally expand. The via wiring 23 is embedded in a through hole 24 penetrating the substrate 10, and is surrounded by the substrate 10. Since the substrate 10 has a smaller linear expansion coefficient than the via wiring 23, the via wiring 23 thermally expands greatly in the vertical direction of the substrate 10. For example, when the substrate 10 is a sapphire substrate, the linear expansion coefficient is 7.35 ppm / °C, and when the via wiring 23 is copper, the linear expansion coefficient is 17.7 ppm / °C. As a result, the via wiring 23 may thermally expand so as to push up the frame 30 and the terminal 22. Note that the thermal expansion is not limited to when the acoustic wave device 500 is mounted on a circuit board by soldering, but may occur in various cases where a temperature rise occurs.

[0049] As shown in FIG. 12(b), when the temperature is lowered to room temperature after being raised, each of the thermally expanded members undergoes thermal contraction. The via wiring 23, which has thermally expanded so as to push up the frame body 30 and the terminal 22, thermally contracts, and thus a gap 78 may be formed between the via wiring 23 and the frame body 30 and between the via wiring 23 and the terminal 22. The formation of the gap 78 may reduce the contact area between the via wiring 23 and the frame body 30 and / or the terminal 22, resulting in an increase in electrical resistance. The gap 78 may also cause an open connection between the via wiring 23 and the frame body 30 and / or the terminal 22. Thus, in the comparative example, electrical connection failure may occur between the via wiring 23 and the frame body 30 and / or the terminal 22.

[0050] [effect] 13 is a cross-sectional view showing the effect of the acoustic wave device 100 according to the first embodiment. As shown in FIG. 1, in the acoustic wave device 100 according to the first embodiment, a gap 33 is formed between the second portion 32 of the frame body 30 and the conductive film 26 in the region where the second portion 32 overlaps with the via wiring 23. Similarly, a gap 27 is formed between the terminal 22 and the conductive film 21 in the region where the terminal 22 overlaps with the via wiring 23. Therefore, as shown in FIG. 13, when the via wiring 23 thermally expands in the vertical direction of the substrate 10, the via wiring 23 and the conductive film 21 protrude into the gap 27, and the via wiring 23 and the conductive film 26 protrude into the gap 33. The conductive film 21 protrudes into the gap 27 and does not contact the terminal 22, and the conductive film 26 protrudes into the gap 33 and does not contact the frame body 30, so that damage to the conductive films 21 and 26 is suppressed. Since the conductive films 21 and 26 are thin, when the via wiring 23 thermally expands and then thermally contracts, the conductive films 21 and 26 follow and continue to contact the via wiring 23. Therefore, the electrical connection between the frame body 30 and the via wiring 23 via the conductive film 26 and the electrical connection between the terminal 22 and the via wiring 23 via the conductive film 21 are well maintained, and the occurrence of poor electrical connection between the via wiring 23 and the frame body 30 and between the via wiring 23 and the terminal 22 is suppressed.

[0051] [Variations] 14(a) and 14(b) are cross-sectional views of the vicinity of the via wiring 23 in the first and second modified examples of the first embodiment. As shown in FIG. 14(a), the via wiring 23 may protrude from the upper surface 11 and / or the lower surface 12 of the substrate 10 before the temperature of the acoustic wave device increases before the acoustic wave device is solder-mounted on the circuit board. As shown in FIG. 14(b), the via wiring 23 may be recessed from the upper surface 11 and / or the lower surface 12 of the substrate 10 before the temperature of the acoustic wave device increases before the acoustic wave device is solder-mounted on the circuit board. As described in FIG. 6(a), the via wiring 23 is formed in the substrate 10 by planarizing the substrate 10 using the CMP method so that the upper surface 11 of the substrate 10 is exposed. As described in FIG. 7(c), the lower surface 12 of the substrate 10 is polished by the CMP method to expose the via wiring 23 from the lower surface 12 of the substrate 10. In these steps, depending on the conditions of the CMP method, the via wiring 23 may protrude or be recessed from the upper surface 11 and / or the lower surface 12 of the substrate 10, as shown in Figures 14(a) and 14(b). If the via wiring 23 protrudes or is recessed significantly, for example, the conductive film 26 may become thinner, increasing resistance or causing disconnection. Therefore, the protrusion amount H and recess amount D of the via wiring 23 from the upper surface 11 and the lower surface 12 of the substrate 10 are preferably 6 μm or less, more preferably 5 μm or less, and even more preferably 4 μm or less.

[0052] As described above, according to the first embodiment and its modified example, the conductive film 26 is provided on the upper surface 11 of the substrate 10 in contact with the via wiring 23 as shown in FIG. The frame body 30 is provided on the upper surface 11 of the substrate 10 in contact with the conductive film 26 and has a gap 33 between the frame body 30 and the conductive film 26 that overlaps with the via wiring 23 in a plan view. This makes it possible to suppress the occurrence of poor electrical connection between the via wiring 23 and the frame body 30 even if the via wiring 23 thermally expands and then thermally contracts. Therefore, a ground potential can be supplied to the frame body 30 and the lid body 40 via the via wiring 23, and the frame body 30 and the lid body 40 can be given the effect of shielding electromagnetic waves.

[0053] 1, the conductive film 21 is provided on the lower surface 12 of the substrate in contact with the via wiring 23. The terminal 22 is provided in contact with the conductive film 21 and has a gap 27 between the terminal 22 and the conductive film 21, the gap 27 overlapping the via wiring 23 in a plan view. This makes it possible to suppress the occurrence of poor electrical connection between the via wiring 23 and the terminal 22 even if the via wiring 23 thermally expands and then thermally shrinks.

[0054] 1, the piezoelectric layer 20 bonded to the upper surface 11 of the substrate 10 has a lower surface 19 that is in direct or indirect contact with the upper surface 11 of the substrate 10 and is spaced apart from the via wiring 23 in plan view. The via wiring 23 is provided outside the area where the piezoelectric layer 20 and the substrate 10 overlap. This makes it possible to prevent cracks and the like from occurring in the piezoelectric layer 20 due to thermal expansion of the via wiring 23. For example, even if the thickness of the piezoelectric layer 20 is reduced to λ or less from the viewpoint of characteristics, it is possible to prevent cracks and the like from occurring in the piezoelectric layer 20.

[0055] 1 and 4, frame body 30 has an annular first portion 31 and a second portion 32 that is provided from first portion 31 toward the inside of the annular shape and overlaps via wiring 23 in a plan view. As shown in FIGS. 5(a) to 5(c), void 33 is provided in second portion 32 from above via wiring 23 toward the inside of the annular shape, and frame body 30 is in contact with conductive film 26 in three directions around void 33. This can ensure airtightness of void 28 in which acoustic wave element 50 is sealed, while suppressing the occurrence of poor electrical connection between via wiring 23 and frame body 30.

[0056] [simulation] A simulation was performed on the thermal expansion amount of the via wiring. The simulation was performed using a 1 / 4 symmetrical model. FIG. 15(a) is an exploded perspective view of the model used in the simulation, and FIG. 15(b) is a cross-sectional view of the model used in the simulation. As shown in FIG. 15(a) and FIG. 15(b), an upper substrate 91 is provided on a frame 92 provided in the peripheral region of the upper surface of a lower substrate 90. A metal layer 93 is provided on the lower surface of the upper substrate 91, and the metal layer 93 is bonded to the frame 92. A frame 94 is provided in the peripheral region of the upper surface of the upper substrate 91. A lid 95 is bonded onto the frame 94. A via wiring 96 penetrating from the upper surface to the lower surface is provided in the lower substrate 90. A via wiring 97 penetrating from the upper surface to the lower surface is provided in the upper substrate 91 at a position overlapping the via wiring 96. A metal pillar 98 is provided adjacent to the via wirings 96 and 97 between the lower substrate 90 and the upper substrate 91.

[0057] The outer lengths of the lower substrate 90, the upper substrate 91, and the lid 95 are defined as L1 and L2. The thickness of the lower substrate 90 is defined as T1, the thickness of the upper substrate 91 is defined as T2, the thickness of the lid 95 is defined as T3, and the thickness of the metal layer 93 is defined as T4. The heights of the frames 92 and 94 are defined as H1 and H2, respectively, and the width is defined as W1. The diameter of the via wiring 96 on the upper surface of the lower substrate 90 is defined as D1, and the diameter on the lower surface is defined as D2. The diameter of the via wiring 97 on the upper surface of the upper substrate 91 is defined as D3, and the diameter on the lower surface is defined as D4. The height of the metal pillar 98 is defined as H3, and the widths are defined as W2 and W3.

[0058] The simulation conditions are as follows. Lower substrate 90, upper substrate 91: sapphire substrate Lid 95: Kovar layer Metal layer 93: Nickel layer Frames 92, 94: Laminated film of copper layer and gold-tin solder layer Via wiring 96, 97: copper layer Metal Pillar 98: A laminate of copper and gold-tin solder layers

[0059] L1, L2=400μm, T1, T2=75μm, T3=30μm, T4=4μm H1, H2, H3=20μm (copper layer: 17μm, gold-tin solder layer: 3μm), W1=30μm, W2, W3=50μm D1, D3 = 40 μm, D2, D4 = 15 μm

[0060] Table 1 shows the Young's modulus, Poisson's ratio, and linear expansion coefficient of each material used in the simulation. [Table 1]

[0061] 15(a) and 15(b), a simulation was performed on the amount of thermal expansion of via wiring 96, 97 when the temperature was increased from 25° C. to 260° C. As the amount of thermal expansion of via wiring 96, 97, the amount of deformation in the thickness direction of lower substrate 90 and upper substrate 91 from point A to point B in FIG.

[0062] Fig. 16 shows the results of a simulation of the amount of thermal expansion of via wiring 96, 97. In Fig. 16, the horizontal axis indicates the distance from point A to point B in µm, with point A in Fig. 15(a) as the origin, and the vertical axis indicates the amount of deformation in the thickness direction of lower substrate 90 and upper substrate 91 in µm. The amount of deformation of the upper surface of lower substrate 90 is indicated by a thin solid line, and the amount of deformation of the lower surface is indicated by a thin dashed line. The amount of deformation of the upper surface of upper substrate 91 is indicated by a thick solid line, and the amount of deformation of the lower surface is indicated by a thick dashed line.

[0063] 16, the upper and lower surfaces of the lower substrate 90 were significantly deformed at the locations where the via wiring 96 was provided, with the deformation amount being approximately 0.5 μm. That is, as the temperature increased from 25° C. to 260° C., the via wiring 96 protruded approximately 0.5 μm in the vertical direction relative to the lower substrate 90. The upper surface of the upper substrate 91 was also significantly deformed at the locations where the via wiring 97 was provided, with the deformation amount being approximately 0.5 μm. On the other hand, the deformation amount of the lower surface of the upper substrate 91 was small. This is believed to be because the metal layer 93 suppressed the deformation of the via wiring 97 toward the lower surface.

[0064] The amount of expansion of an object can be calculated by multiplying the linear expansion coefficient by the original length by the temperature rise. The conditions for this simulation are that the linear expansion coefficient of the lower substrate 90 and the upper substrate 91 is 7.35 ppm / °C, the thickness is 75 μm, and the temperature rise is 235°C, and the linear expansion coefficient of the via wirings 96 and 97 is 17.7 ppm / °C, the thickness is 75 μm, and the temperature rise is 235°C. In this case, the difference in the amount of expansion between the via wirings 96 and 97 and the lower substrate 90 and the upper substrate 91 is calculated to be about 0.18 μm. In the simulation results, the amount of protrusion of the via wirings 96 and 97 was about 0.5 μm, which is roughly correct. From this, it can be said that the amount of protrusion of the via wirings 96 and 97 is proportional to the thickness of the lower substrate 90 and the upper substrate 91. In the simulation, when the thicknesses T1, T2 of the lower substrate 90 and the upper substrate 91 were 75 μm, the protrusion amount of the via wirings 96, 97 was about 0.5 μm, so that the protrusion amount of the via wirings 96, 97 was about 0.007 times the thicknesses T1, T2.

[0065] In Example 1, in order to prevent the conductive films 21, 26 from contacting the terminal 22 or the frame body 30 even when the via wiring 23 is thermally expanded, the minimum height H1 (see FIGS. 3(b) and 3(c)) of the void 27 in the region overlapping the via wiring 23 in a planar view and the minimum height H2 (see FIGS. 5(b) and 5(c)) of the void 33 in the region overlapping the via wiring 23 are preferably 1.0 μm or more, more preferably 2.0 μm or more, and even more preferably 3.0 μm or more. That is, the minimum heights H1 and H2 are preferably 0.01 times or more, more preferably 0.025 times or more, and even more preferably 0.04 times or more of the thickness of the substrate 10. EXAMPLES

[0066] Fig. 17 is a cross-sectional view of an acoustic wave device 200 in accordance with a second embodiment. As shown in Fig. 17, in the acoustic wave device 200 in accordance with the second embodiment, a piezoelectric layer 20a is bonded to an upper surface 11a of a substrate 10a. An acoustic wave element 50a is provided on the piezoelectric layer 20a. The piezoelectric layer 20a is not provided in the peripheral region of the upper surface 11a, and a frame body 30a is provided surrounding the piezoelectric layer 20a. A substrate 10b is provided on the frame body 30a. The acoustic wave element 50a is sealed in a gap 28a between the substrates 10a and 10b by the frame body 30a and the substrate 10b.

[0067] The substrate 10a is provided with a via wiring 23a penetrating from the upper surface 11a to the lower surface 12a. A conductive film 26a and a wiring 25a are provided on the upper surface 11a of the substrate 10a, which contact and cover the via wiring 23a. A metal pillar 29 is provided on the via wiring 23a in the void 28a. The metal pillar 29 is, for example, a copper pillar, but may be another metal pillar. The metal pillar 29 contacts the conductive film 26a or the wiring 25a, and has a void 34 between the conductive film 26a or the wiring 25a, which overlaps with the via wiring 23a in a plan view. The metal pillar 29 also contacts the metal layer 35, and has a void 34a between the metal layer 35, which overlaps with the via wiring 23b in a plan view.

[0068] A conductive film 21 and a terminal 22 are provided on the lower surface 12a of the substrate 10a. The conductive film 21 is provided in contact with and covers the via wiring 23a, similar to Example 1. The terminal 22 is in contact with the conductive film 21, similar to Example 1, and has a gap 27 between the terminal 22 and the conductive film 21, which overlaps with the via wiring 23a in a plan view.

[0069] A metal layer 35 is provided on the bottom surface of the substrate 10b, and the metal layer 35 is bonded to the frame 30a and the metal pillar 29. A piezoelectric layer 20b is bonded to the top surface 11b of the substrate 10b. An acoustic wave element 50b is provided on the piezoelectric layer 20b. The piezoelectric layer 20b is not provided in the peripheral region of the top surface 11b, and a frame 30b is provided surrounding the piezoelectric layer 20b. A lid 40 is provided on the frame 30b. The acoustic wave element 50b is sealed in the gap 28b between the substrate 10b and the lid 40 by the frame 30b and the lid 40.

[0070] Substrate 10b is provided with via wiring 23b penetrating from upper surface 11b to lower surface 12b. Via wiring 23b is connected to metal pillar 29 through metal layer 35. Acoustic wave element 50b is electrically connected to terminal 22 through via wiring 23b, metal pillar 29, and via wiring 23a.

[0071] A metal film 36 is provided covering the substrate 10a, the frame 30a, the substrate 10b, the frame 30b, and the cover 40. The metal film 36 is connected to a ground terminal 22 on the lower surface 12a of the substrate 10a.

[0072] FIG. 18(a) is a plan view of the vicinity of the via wiring 23a in the second embodiment as viewed from the +Z direction, FIG. 18(b) is an AA cross-sectional view of FIG. 18(a), and FIG. 18(c) is a BB cross-sectional view of FIG. 18(a). In FIG. 18(a), the portion where the metal pillar 29 contacts the conductive film 26a is hatched. As shown in FIG. 18(a) to FIG. 18(c), the conductive film 26a covers the via wiring 23a in a shape larger than the via wiring 23a in a plan view. The metal pillar 29 has a gap 34 between it and the conductive film 26a, which overlaps with the via wiring 23a in a plan view. The gap 34 is larger than the via wiring 23a in a plan view. The metal pillar 29 contacts the conductive film 26a around the gap 34. For example, the gap 34 is a tunnel-shaped gap penetrating the metal pillar 29 in the X direction. The metal pillar 29 is in contact with the conductive film 26a on both sides of the void 34 in the Y direction. Note that the void 34 is not limited to penetrating the metal pillar 29, and may not penetrate the metal pillar 29, similar to the void 33 in Figures 5(a) to 5(c).

[0073] The metal pillar 29 has a gap 34a having the same shape as the gap 34 between it and the metal layer 35 in the region overlapping with the via wiring 23b. The gap 34a has the same shape as the gap 34 in Figures 18(a) to 18(c), so it is not shown in the figures.

[0074] [Variations] In the second embodiment, the protruding electrode provided on the via wiring 23a is the metal pillar 29, but in the modified example of the second embodiment, the protruding electrode is a bump. Also, in the modified example of the second embodiment, the void 34b does not penetrate the bump 38.

[0075] 19(a) to 19(d) are cross-sectional views showing a method for forming a bump 38 in a modified example of the second embodiment. As shown in FIG. 19(a), at least a resist film 79 is formed in a location where a gap 34b between the bump 38 and the conductive film 26a is to be formed. The resist film 79 is formed by applying a resist, exposing it to light, and developing it. Next, a metal seed layer 37 is formed on the upper surface 11a of the substrate 10a by using, for example, a sputtering method. The metal seed layer 37 is formed to cover the resist film 79 and to be in contact with the conductive film 26a.

[0076] As shown in FIG. 19(b), bumps 38 are formed in contact with the metal seed layer 37 at locations where the resist film 79 is not provided and extending from these locations onto the resist film 79.

[0077] 19(c), the metal seed layer 37 is removed by etching using the bumps 38 as a mask. The metal seed layer 37 and the bumps 38 are combined to form the bumps 38.

[0078] 19(d), the resist film 79 is removed by, for example, wet etching. As a result, a bump 38 is formed on the via wiring 23a, the bump having a gap 34b between the conductive film 26a and the via wiring 23a in the region overlapping the via wiring 23a. The bump 38 is, for example, a gold bump or a copper bump, but may be another metal bump.

[0079] According to the second embodiment and its modified example, as shown in Fig. 18(a) to Fig. 18(c) and Fig. 19(d), the conductive film 26a is provided on the upper surface 11a of the substrate 10a in contact with the via wiring 23a. The metal pillar 29 and the bump 38 are provided on the upper surface 11a of the substrate 10 in contact with the conductive film 26a and have gaps 34, 34b between them and the conductive film 26a, which overlap with the via wiring 23a in a plan view. This makes it possible to suppress the occurrence of poor electrical connection between the via wiring 23a and the metal pillar 29 and the bump 38, even if the via wiring 23a thermally expands and then thermally contracts.

[0080] 18(a) to 18(c), the void 34 is provided penetrating the metal pillar 29, and the metal pillar 29 is in contact with the conductive film 26a on both sides of the void 34. This makes it possible to easily form the void 34 penetrating the metal pillar 29.

[0081] 17, substrate 10b is provided on upper surface 11a of substrate 10a with gap 28a therebetween. Acoustic wave element 50b is provided on substrate 10b. Acoustic wave element 50b is connected to metal pillar 29 or bump 38 through via wiring 23b provided to penetrate substrate 10b. Since electrical connection failure between via wiring 23a and metal pillar 29 and between via wiring 23a and bump 38 is suppressed, electrical connection failure between acoustic wave element 50b and via wiring 23a can be suppressed.

[0082] In the first and second embodiments, the piezoelectric layer is bonded to the substrate, and the elastic wave element is provided on the piezoelectric layer, but the functional element may be other than the elastic wave element. The functional element may be a MEMS (Micro Electro Mechanical System) element or an odor sensor element, or may be other than the piezoelectric element. EXAMPLES

[0083] FIG. 20 is a circuit diagram of a filter 300 according to a third embodiment. As shown in FIG. 20, in the filter 300 according to the third embodiment, one or more series resonators S1 to S4 are connected in series between an input terminal Tin and an output terminal Tout. One or more parallel resonators P1 to P3 are connected in parallel between the input terminal Tin and the output terminal Tout. The acoustic wave device according to the first or second embodiment may be used for at least one of the series resonators S1 to S4 and the parallel resonators P1 to P3. The numbers of the series resonators and the parallel resonators can be appropriately set. Although a ladder-type filter is shown as an example of the filter, the filter may be a multimode filter. EXAMPLES

[0084] FIG. 21 is a circuit diagram of a duplexer 400 according to a fourth embodiment. As shown in FIG. 21, in the duplexer 400 according to the fourth embodiment, a transmission filter 80 is connected between a common terminal Ant and a transmission terminal Tx. A reception filter 82 is connected between the common terminal Ant and a reception terminal Rx. The transmission filter 80 passes a signal in a transmission band among high-frequency signals inputted from the transmission terminal Tx to the common terminal Ant as a transmission signal, and suppresses signals of other frequencies. The reception filter 82 passes a signal in a reception band among high-frequency signals inputted from the common terminal Ant to the reception terminal Rx as a reception signal, and suppresses signals of other frequencies. At least one of the transmission filter 80 and the reception filter 82 may be the filter of the third embodiment. Although a duplexer has been shown as an example of a multiplexer, a triplexer or a quadplexer may be used.

[0085] Although the embodiment of the present invention has been described in detail above, the present invention is not limited to such specific embodiment, and various modifications and variations are possible within the scope of the gist of the present invention described in the claims. [Explanation of symbols]

[0086] 10, 10a, 10b...substrate, 11, 11a, 11b...upper surface, 12, 12a, 12b...lower surface, 18...upper surface, 19...lower surface, 20, 20a, 20b...piezoelectric layer, 21...conductive film, 22...terminal, 23, 23a, 23b...via wiring, 24...through hole, 25, 25a, 25b...wiring, 26, 26a...conductive film, 27...void, 28, 28a, 28b...void, 29...metal pillar, 30, 30a, 30b...frame, 31...first portion, 32...second portion, 33...void, 34, 34a...void, 35...metal layer, 36...metal film, 37...metal seed layer, 38...bump, 40...lid, 50, 50a, 50b...acoustic wave element, 51...IDT , 52...reflector, 53...comb-shaped electrode, 54...electrode finger, 55...bus bar, 61...lower electrode, 62...piezoelectric layer, 63...upper electrode, 64...gap, 65...resonance region, 70...resist film, 71...metal seed layer, 72...plating resist film, 73...opening, 75...resist film, 76...plating resist film, 77...opening, 78...gap, 79...resist film, 80...transmitting filter, 82...receiving filter, 90...lower substrate, 91...upper substrate, 92...frame, 93...metal layer, 94...frame, 95...lid, 96, 97...via wiring, 98...metal pillar, 100, 200, 500...acoustic wave device, 300...filter, 400...duplexer

Claims

1. A substrate; A functional element provided on a first surface of the substrate; a via wiring embedded in a through hole provided from the first surface to a second surface opposite to the first surface of the substrate; a conductive film provided on the first surface of the substrate in contact with the via wiring; a frame that surrounds the functional element in a plan view, is provided on the first surface of the substrate, has a first gap between the conductive film and the frame, the first gap overlapping the via wiring in a plan view, and is in contact with the conductive film; a lid provided on the frame with a second gap sandwiched between the substrate and the lid, the lid sealing the functional element within the second gap.

2. Another conductive film provided on the second surface of the substrate in contact with the via wiring; The electronic component according to claim 1 , further comprising: a metal film provided on the second surface of the substrate, the metal film having a third gap between the other conductive film and the other conductive film, the third gap overlapping the via wiring in a planar view, and contacting the other conductive film.

3. a piezoelectric layer provided on the first surface of the substrate, the lower surface of the piezoelectric layer being in direct or indirect contact with the first surface and spaced apart from the via wiring; the functional element is an elastic wave element provided on the piezoelectric layer, The electronic component according to claim 1 , wherein the via wiring is provided outside a region where the piezoelectric layer and the substrate overlap.

4. the frame body has an annular first portion and a second portion provided from the first portion toward the inside of the annular shape and overlapping with the via wiring in a plan view, the first gap is provided in the second portion from above the via wiring toward the inside of the ring and is connected to the second gap; The electronic component according to claim 1 , wherein the frame is in contact with the conductive film in three directions around the first gap.

5. 3. The electronic component according to claim 1, wherein in a region where the via wiring and the frame body overlap in a planar view, the minimum height of the first gap between the frame body and the conductive film is 0.01 times or more the thickness of the substrate.

6. A substrate; a piezoelectric layer provided on a first surface of the substrate, the lower surface of the piezoelectric layer being in direct or indirect contact with the first surface; an elastic wave element provided on the piezoelectric layer; a via wiring embedded in a through hole provided from the first surface to a second surface opposite to the first surface of the substrate; a conductive film provided on the first surface of the substrate in contact with the via wiring; an elastic wave device comprising: a protruding electrode that is arranged on the first surface of the substrate so as to overlap the via wiring in a planar view, has a gap between the conductive film and the protruding electrode, the gap overlapping the via wiring in a planar view, and contacts the conductive film.

7. the gap is provided penetrating the protruding electrode, The acoustic wave device according to claim 6 , wherein the protruding electrodes are in contact with the conductive film on both sides of the gap.

8. Another substrate provided on the first surface of the substrate via a gap; Another acoustic wave element provided on the other substrate; and The acoustic wave device according to claim 6 , further comprising: another via wiring provided to penetrate the other substrate and connected between the other acoustic wave element and the protruding electrode.

9. A filter comprising the electronic component according to claim 3 or the acoustic wave device according to claim 6.

10. A multiplexer comprising the filter of claim 9.

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