Piezoelectric vibration element and piezoelectric device

Abstract

This piezoelectric vibration element comprises a plate-shaped piezoelectric piece, two excitation electrodes, two mounted electrodes, and a reinforcing member. The piezoelectric piece has a first surface and a second surface. The reinforcing member reinforces the mounted electrodes. The piezoelectric piece includes: a through hole that overlaps the mounted electrode positioned on the first surface in a plan view and extends between the first surface and the second surface; and a conductive layer that is connected to the mounted electrode on the first surface and extends along the inner wall surface of the through hole. The reinforcing member is positioned so as to overlap at least a portion of the through hole on the first surface, has a thickness of 2 μm or less along the direction of extension of the through hole, and is an insulator or a semiconductor.

Description

Piezoelectric vibration element and piezoelectric device

[0001] The present disclosure relates to a piezoelectric vibration element and a piezoelectric device.

[0002] In a piezoelectric vibrating element, excitation electrodes for exciting vibrations are located on both sides of the piezoelectric strip. U.S. Patent No. 10,141,906 discloses a technology in which the piezoelectric strip has through-holes and an electrical path is established within the through-holes in order to electrically connect excitation electrodes located on the side of the piezoelectric strip that does not face the mounting surface of the package to electrodes on the mounting surface.

[0003] One aspect of the present disclosure is a piezoelectric vibration element comprising: (1) a plate-shaped piezoelectric piece having a first surface and a second surface opposite to the first surface, two excitation electrodes located on the first surface and the second surface, two mounting electrodes electrically connected to the excitation electrodes on the first surface and the second surface, respectively, and a reinforcing member reinforcing the mounting electrodes, wherein the piezoelectric piece has a through hole overlapping the mounting electrode located on the first surface in a plan view and extending between the first surface and the second surface, and a conductive layer connected to the mounting electrode on the first surface and extending between the first surface and the second surface along an inner wall surface of the through hole, the reinforcing member being located on the first surface so as to overlap at least a portion of the through hole, having a thickness of 2 μm or less along the extension direction of the through hole, and being an insulator or a semiconductor. (2) The piezoelectric vibration element of (1), wherein the mounting electrode is located between the reinforcing member and the through hole. (3) The piezoelectric vibration element of (1) or (2), wherein the reinforcing member overlaps the entire through hole in a planar view. (4) The piezoelectric vibration element of any of (1) to (3), wherein the planar view area of ​​the reinforcing member is included in the planar view area of ​​the mounting electrode on the first surface. (5) The piezoelectric vibration element of any of (1) to (4), wherein the second surface is provided with an intermediate electrode connected to the mounting electrode on the first surface via the conductive layer, the intermediate electrode being in an area overlapping the mounting electrode in a planar view. (6) The piezoelectric vibration element of any of (1) to (5), wherein the insulator or semiconductor includes silicon. (7) A piezoelectric device comprising: the piezoelectric vibration element of any of (1) to (6); and a package having a recess that houses the piezoelectric vibration element, wherein the piezoelectric vibration element is bonded to the bottom surface of the recess with a conductive bonding material. (8) The piezoelectric device of (7), wherein a portion of the conductive bonding material is located within the through hole.

[0004] 1A and 1B are an overall perspective view of a piezoelectric device including a piezoelectric vibration element, a plan view of the piezoelectric vibration element, a cross-sectional view of the piezoelectric vibration element, and a cross-sectional view of the piezoelectric device.

[0005] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described with reference to the accompanying drawings. Fig. 1 is an overall perspective view of a piezoelectric device 1 including a piezoelectric vibration element 10 according to the present embodiment.

[0006] The piezoelectric device 1 includes a piezoelectric vibration element 10, a package 20, and a lid 30. The piezoelectric vibration element 10 converts deformation vibration near a resonance frequency into an electrical signal corresponding to the deformation. The piezoelectric vibration element 10 will be described later.

[0007] The package 20 includes a housing 21 having an open recess 20a on one side, a connection electrode 22, and an external electrode 23. The open side of the recess 20a is defined as the +Z side. Two connection electrodes 22 are located on the bottom surface opposite the open side of the recess 20a and are connected to the piezoelectric vibration element 10. This allows the piezoelectric vibration element 10 to be housed within the recess 20a. The package 20 has a rectangular shape when viewed from the Z direction in plan. The rectangular shape may include shapes with rounded corners or castellations. Here, the longitudinal axis direction within the recess 20a is defined as the +X direction, and two connection electrodes 22 are located side by side in the Y direction near the tip of the housing 21 on the +X side. The housing 21 is an insulator, and may be made of, for example, a ceramic material, a semiconductor material, a glass material, or a combination thereof. The package 20 may have electrical wiring (not shown) inside. The conductor may be, for example, molybdenum, copper, silver, tungsten, or the like. The surfaces of some or all of the signal lines may be plated with nickel, gold, etc. The electrical wiring connects the connection electrodes 22 and the external electrodes 23, for example.

[0008] The external electrodes 23 are located on the bottom surface on the −Z side of the package 20. The external electrodes 23 are connected to an external board and acquire control information from an electronic device or the like that has the external board.

[0009] The lid 30 is joined to the upper end of the recess 20a to seal the recess 20a. The lid 30 may be flat and have substantially the same shape as the package 20 in a plan view. The lid 30 may be made of a conductive metal. Examples of the metal include iron, copper, nickel, cobalt, molybdenum, or tungsten, or an alloy thereof, such as kovar. The lid 30 is joined to the package 20 by a joining member. The joining member may be a conductive joining member. The conductive joining member may be, for example, a brazing material or solder. Alternatively, the lid 30 may be made of ceramic or glass. The sealed recess 20a may be substantially vacuum or reduced pressure. This reduces air resistance to the vibration of the piezoelectric vibration element 10. The gas in the recess 20a may be an inert gas, nitrogen, or ordinary air.

[0010] Fig. 2 is a plan view of the piezoelectric vibration element 10. Fig. 3 is a cross-sectional view of the piezoelectric vibration element 10. This cross-sectional view shows a cross section taken along the cross-sectional line iii in Fig. 2.

[0011] The piezoelectric vibrating element 10 includes a piezoelectric strip 11, an excitation electrode 12, a mounting electrode 13, a lead wire 14, and a reinforcing member 15. The piezoelectric strip 11 is a plate-shaped piezoelectric vibrating strip, and may be, for example, a quartz crystal strip such as an AT-cut quartz crystal plate. In this case, the X-axis direction may coincide with the crystal axis direction of the piezoelectric strip 11. The piezoelectric strip 11 may be flat. Alternatively, the piezoelectric strip 11 may have portions with varying thicknesses. For example, the piezoelectric strip 11 may have an inverted mesa shape in which the vibrating portion is locally thin. In the following, of the two plate surfaces, the +Z side surface of the piezoelectric device 1 that does not face the package 20 is referred to as the first surface 10a. The -Z side surface that faces the package 20 is referred to as the second surface 10b. The first surface 10a and the second surface 10b may have different shapes. That is, only one surface may have a concave or convex shape. Furthermore, the piezoelectric vibration element 10 may have grooves or other through holes that do not affect the positions of the excitation electrodes 12, the mounting electrodes 13, and the lead wires 14.

[0012] The excitation electrodes 12 are located on the first surface 10a and the second surface 10b of the piezoelectric piece 11, respectively. The two excitation electrodes 12 are located at approximately the same position in a plan view. The excitation electrodes 12 may be elliptical. Alternatively, the excitation electrodes 12 may be rectangular or have another shape. The excitation electrodes 12 are electrically connected to the mounting electrodes 13 via lead wires 14, respectively. The lead wires 14 may extend obliquely with respect to the X-axis direction.

[0013] The two mounting electrodes 13 may be located at the same position in the X-axis direction and side by side in the Y-axis direction in a plan view. In Fig. 2, the mounting electrode 13 on the first surface 10a is located on the +Y side and the mounting electrode 13 on the second surface 10b is located on the -Y side, but their positions may be reversed. Alternatively, the two mounting electrodes 13 may be located at the same position in the Y-axis direction and near both ends in the X-axis direction.

[0014] The excitation electrode 12, the mounting electrode 13, and the lead wire 14 may each be made of a highly conductive material, mainly a metal. The excitation electrode 12, the mounting electrode 13, and the lead wire 14 may be made of the same material. The metal may be, for example, molybdenum, copper, silver, tungsten, or the like. Furthermore, some or all of the surfaces may be plated with nickel, gold, or the like.

[0015] The reinforcing member 15 is located on the mounting electrode 13 on the first surface 10a. The reinforcing member 15 is an insulator or a semiconductor. The reinforcing member 15 may be resistant to elastic deformation, i.e., have a high elastic modulus. The insulator may be, for example, a silicon oxide, nitride, or oxynitride, and the semiconductor may be silicon, polysilicon, or amorphous silicon. The silicon may also contain a doped layer of boron, phosphorus, or the like. That is, the reinforcing member 15 may contain silicon. Furthermore, as described below, the reinforcing member 15 has a thickness that provides the required rigidity, i.e., is resistant to plastic deformation. The reinforcing member 15 may be approximately the same thickness as the excitation electrode 12, the mounting electrode 13, and the lead wire 14, for example, 100 nm or more, or even thicker. On the other hand, an excessively thick reinforcing member 15 may affect the low profile of the piezoelectric device 1. For example, the reinforcing member 15 may be 2 μm or less. The non-conductive reinforcing member 15 reduces parasitic capacitance between the excitation electrode 12 and the connection electrode 22. The reinforcing member 15 may be obtained by using a photoresist or the like on the mounting electrode 13 when the piezoelectric vibration element 10 is formed on a wafer, for example.

[0016] The reinforcing member 15 is smaller than the mounting electrode 13 in a planar view and may be included within the planar view range of the mounting electrode 13. As will be described later, a through hole 111 connecting the first surface 10a and the second surface 10b of the piezoelectric piece 11 is located below the reinforcing member 15. That is, the reinforcing member 15 overlaps at least a portion of, and in this case the entirety of, the through hole 111 in a planar view. The reinforcing member 15 reinforces the mounting electrode 13 in order to reduce adverse effects caused by force applied to the mounting electrode 13 located at the opening of the through hole 111 when separating and individualizing the multiple piezoelectric vibration elements 10 formed on the wafer.

[0017] Furthermore, in order to adjust the resonant frequency of the piezoelectric vibration element 10, the thickness of the electrical wiring on the first surface 10a, primarily the excitation electrode 12, is reduced by ion beam irradiation. In this process, in a piezoelectric vibration element 10 with a high resonant frequency and a small size, the beam irradiation diameter may not be narrowed sufficiently, and the reinforcing member 15 may also be removed. If the reinforcing member 15 is conductive, changes in the combined thickness of the mounting electrode 13 and the reinforcing member 15, which form a cross section perpendicular to the current path, can have a significant impact on electrical resistance. If the mounting electrode 13 and the reinforcing member 15 have the same resistivity, electrical resistance may increase in inverse proportion to the reduced thickness. For example, if the mounting electrode 13 and the reinforcing member 15 have the same resistance value, halving the thickness of the reinforcing member 15 increases the resistance value by 33%. If the reinforcing member 15 is an insulator or semiconductor, changes in the thickness of the reinforcing member 15 have little impact on electrical resistance as long as the thickness of the mounting electrode 13 is maintained. For example, if the resistance of the reinforcing member 15 is 1000 times the resistance of the mounting electrode 13, even if the thickness of the reinforcing member 15 is halved, the resistance value will increase by 0.05%. The electrical resistance of the reinforcing member 15 may be, for example, a resistivity of 1 mΩ m or more. The above-mentioned silicon and its compounds have a resistivity of more than 1 mΩ m.

[0018] As shown in FIG. 3 , the piezoelectric piece 11 has a through hole 111 extending between the first surface 10a and the second surface 10b. An intermediate electrode 13r is located on the second surface 10b around the opening of the through hole 111, overlapping with the mounting electrode 13 on the first surface 10a. A wall conductor 112 serving as a conductive layer is located on the inner wall surface of the through hole 111, electrically connecting the mounting electrode 13 on the first surface 10a to the intermediate electrode 13r. This provides a direct connection from the mounting electrode 13 on the first surface 10a to the connection electrode 22, thereby shortening the path length compared to conventional paths, particularly those using bonding wires, and reducing increases in parasitic capacitance and parasitic resistance. The wall conductor 112 may be located across the entire inner wall surface of the through hole 111, or may be located on a portion of the inner wall surface that is free of the wall conductor 112 as long as it connects the opening on the first surface 10a to the opening on the second surface 10b.

[0019] Although the through hole 111 has a tapered shape in cross section in FIG. 3 , this is not a limitation. The cross section of the through hole 111 parallel to the Z axis may have a constant width. The cross section may also be circular, elliptical, rectangular, or a rectangular shape with rounded or chamfered corners. The intermediate electrode 13r on the second surface 10b and the mounting electrode 13 on the second surface 10b are joined to the connection electrode 22 of the package 20 via a bonding member 40. Although the shape of the through hole 111 in plan view is a square with rounded corners in FIG. 2 , this is not a limitation. The through hole 111 is smaller than the mounting electrode 13, the intermediate electrode 13r, and the reinforcing member 15 in plan view, and is included within the range of each of them in plan view.

[0020] The bonding member 40 is a conductive bonding material that is deformable before bonding. By processing after bonding, for example, by heating, the bonding member 40 hardens and bonds and fixes the piezoelectric vibration element 10 and the package 20. A material having a thermal expansion coefficient close to that of the piezoelectric piece 11 may be selected for the bonding member 40. For example, the bonding member 40 may be a conductive adhesive containing silver particles in a resin, i.e., a silver paste.

[0021] 4 is a cross-sectional view of the piezoelectric device 1. This cross section is taken along the cross-sectional line iii when the piezoelectric vibrating element 10 is mounted in the package 20.

[0022] The package 20 includes a substrate 211 forming the bottom surface and a frame 212 surrounding the substrate 211 along the side surfaces of the substrate 211. The substrate 211 and the frame 212 may be the same member and may have an integrated shape. The connection electrode 22 is located on the substrate 211. As described above, the intermediate electrode 13r is joined to the connection electrode 22 by the joining member 40. At this time, a portion of the joining member 40 also enters the through-hole 111. This increases at least a portion of the cross-sectional area of ​​the electrical path between the mounting electrode 13 and the intermediate electrode 13r, thereby reducing an increase in electrical resistance.

[0023] On the other hand, in FIG. 4 , a gap remains between the upper end of the bonding member 40 and the mounting electrode 13. However, depending on the mounting state of the piezoelectric vibration element 10 in the package 20, the gap may be small or absent. In this case, pressure may be applied to the mounting electrode 13 due to penetration of the bonding member 40 into the through-hole 111 and expansion during thermal fixation. The reinforcing member 15 can press the upper surface of the mounting electrode 13 to reinforce the mounting electrode 13 so that the pressure does not adversely affect the mounting electrode 13 when the piezoelectric vibration element 10 is mounted on the mounting electrode 13. As described above, the reinforcing member 15 has a thickness at least as large as that of the mounting electrode 13 and is made of a material that is difficult to deform, so that the reinforcing member 15 has a rigidity greater than or equal to that of the mounting electrode 13 to reduce deformation of the mounting electrode 13.

[0024] As described above, the piezoelectric vibration element 10 of this embodiment includes a plate-shaped piezoelectric piece 11, two excitation electrodes 12, two mounting electrodes 13, and a reinforcing member 15. The piezoelectric piece 11 has a first surface 10a and a second surface 10b opposite the first surface 10a. The excitation electrodes 12 are located on both the first surface 10a and the second surface 10b. The mounting electrodes 13 are electrically connected to the excitation electrodes 12 on both the first surface 10a and the second surface 10b. The reinforcing member 15 reinforces the mounting electrodes 13. The piezoelectric piece 11 has a through-hole 111 that overlaps with the mounting electrode 13 located on the first surface 10a in a plan view and extends between the first surface 10a and the second surface 10b. The piezoelectric piece 11 also has a wall conductor 112 that connects to the mounting electrode 13 on the first surface 10a and extends between the first surface 10a and the second surface 10b along the inner wall surface of the through hole 111. The reinforcing member 15 is positioned on the first surface 10a, overlapping at least a portion of the opening of the through hole 111. The reinforcing member 15 has a thickness of 2 μm or less along the Z direction, which is the extension direction of the through hole 111. The reinforcing member 15 is an insulator or a semiconductor. As described above, the present disclosure has a structure in which the wall conductor 112 in the through hole 111 connects electrical wiring directly from the mounting electrode 13 on the first surface 10a to the second surface 10b. In this case, the reinforcing member 15 reinforces the mounting electrode 13 on the first surface 10a at a position where it at least partially overlaps the through hole 111. The reinforcing member 15 is an insulator or a semiconductor. As a result, when the thickness of the excitation electrode 12 is reduced to adjust the resonance frequency of the piezoelectric vibration element 10, even if the reinforcing member 15 is also removed, the impact on the resistance value and parasitic capacitance of the electrical wiring is reduced.

[0025] Furthermore, the mounting electrode 13 may be located between the reinforcing member 15 and the through hole 111. This allows the bonding member 40 penetrating into the through hole 111 to come into contact with the mounting electrode 13, reinforces the mounting electrode 13, and makes it less likely for the bonding member 40 to leak out onto the first surface 10a. This increases the bonding area between the mounting electrode 13 and the bonding member 40, resulting in better electrical connection.

[0026] Furthermore, the reinforcing member 15 may overlap the entire through hole 111 in a plan view. This allows the reinforcing member 15 to more reliably reinforce the mounting electrode 13 on the through hole 111, and reduces adverse effects that may be caused by the bonding member 40 when the piezoelectric vibration element 10 is mounted on the package 20.

[0027] Furthermore, the planar view range of the reinforcing member 15 may be included within the planar view range of the mounting electrode 13 on the first surface 10a. That is, the reinforcing member 15 may be smaller than the mounting electrode 13 within the range of the mounting electrode 13 in a planar view. Since the reinforcing member 15 is not positioned outside the mounting electrode 13 to be reinforced, the reinforcing member 15 and the piezoelectric strip 11 are not in direct contact. This reduces the effect of the difference in thermal expansion coefficient between the reinforcing member 15 and the piezoelectric strip 11, thereby reducing frequency fluctuations due to deformation in response to thermal stress. Furthermore, the piezoelectric vibration element 10 can reduce the adverse effects of the reinforcing member 15 on vibration. Furthermore, by reducing the portion protruding from the piezoelectric strip 11 when mounting the piezoelectric vibration element 10 in the package 20, the mounting machine can more easily hold the piezoelectric vibration element 10 properly.

[0028] The piezoelectric vibration element 10 may also include an intermediate electrode 13r located on the second surface 10b and connected to the mounting electrode 13 on the first surface 10a via the wall conductor 112. The intermediate electrode 13r may be located in an area that overlaps the mounting electrode 13 in a planar view. This reduces the increase in the total size of the mounting electrode 13 and the intermediate electrode 13r in a planar view, thereby reducing the increase in size of the piezoelectric vibration element 10.

[0029] The insulator or semiconductor of the reinforcing member 15 may also contain silicon. Silicon and its compounds tend to have high rigidity and can be easily formed into thin film layers at low cost, making them suitable for use as the reinforcing member 15.

[0030] The piezoelectric device 1 of this embodiment includes the above-described piezoelectric vibration element 10 and a package 20 having a recess 20a that houses the piezoelectric vibration element 10. The piezoelectric vibration element 10 is bonded to the bottom surface of the recess 20a with a conductive bonding member 40. With this piezoelectric device 1, the piezoelectric vibration element 10, whose resonant frequency has been adjusted, can be more easily fixed and housed appropriately in the recess 20a.

[0031] Furthermore, a portion of the conductive bonding member 40 may be located within the through-hole 111. This reduces the resistance value in the electrical path between the excitation electrode 12 on the first surface 10a and the connection electrode 22. On the other hand, the reinforcing member 15 reduces adverse effects on the mounting electrode 13, allowing the piezoelectric vibration element 10 to vibrate with greater precision.

[0032] The above embodiment is merely an example, and various modifications are possible. For example, in the above embodiment, the reinforcing member 15 is positioned so as to overlap the entire through-hole 111 in a plan view, but this is not limiting. The reinforcing member 15 may overlap only a portion of the through-hole 111 in a plan view.

[0033] Furthermore, the reinforcing member 15 does not have to be located within the range of the mounting electrode 13 in plan view. A portion of the reinforcing member 15 may protrude from the mounting electrode 13.

[0034] Furthermore, the intermediate electrode 13r may extend beyond the area overlapping with the mounting electrode 13 on the first surface 10a. The intermediate electrode 13r, including the extending portion, may be joined to the connection electrode 22 by the joining member 40. Alternatively, the piezoelectric vibration element 10 may not have the intermediate electrode 13r, and electrical continuity may be achieved by joining the wall conductor 112 to the joining member 40.

[0035] In the above description, the through-holes 111 and the reinforcing members 15 are positioned so as to overlap, in plan view, with the mounting electrodes 13 electrically connected to the excitation electrodes 12 on the first surface 10a, but this is not limiting. The through-holes 111 may be positioned so as to overlap, in plan view, with the mounting electrodes 13 electrically connected to the excitation electrodes 12 on the second surface 10b, and an intermediate electrode used for testing may be positioned on the first surface 10a side of the through-holes 111. A reinforcing member may be positioned on this intermediate electrode.

[0036] Furthermore, the reinforcing member 15 does not necessarily have to be located above the mounting electrode 13. The reinforcing member 15 may be located on the first surface 10a so as to cover a portion of the opening of the through hole 111, and the mounting electrode 13 may be located on the reinforcing member 15. It is sufficient that the mounting electrode 13 and the wall surface conductor 112 in the through hole 111 are connected to each other via a portion of the opening of the through hole 111 that is not covered by the reinforcing member 15.

[0037] Furthermore, the shape of the package 20 is not limited to the above. The bottom surface of the recess 20a may not be flat. For example, the bottom surface of the recess 20a may have a step where the connection electrode 22 is positioned one step higher than the other parts. Furthermore, components other than the piezoelectric vibration element 10 may be mountable within the recess 20a. Alternatively, the package 20 may have a recess other than the recess 20a, for example, on the bottom surface, and other electronic components may be fixed to the bottom surface.

[0038] Furthermore, the piezoelectric piece 11 may be a piezoelectric material other than quartz. In this case, other suitable materials may be selected for the reinforcing member 15 or the bonding member 40 depending on the thermal expansion coefficient of the piezoelectric material. Alternatively, the piezoelectric piece 11 may be a quartz piece other than an AT-cut quartz plate.

[0039] Furthermore, the piezoelectric vibration element 10 may be distributed separately from the package 20 or the lid 30 .

[0040] In addition, the specific details of the structure, configuration, material, size, etc. shown in the above embodiment can be appropriately changed without departing from the spirit of this disclosure. The scope of the present invention includes the scope of the invention described in the claims and its equivalents.

[0041] The present disclosure can be used for piezoelectric vibration elements and piezoelectric devices.

[0042] REFERENCE SIGNS LIST 1 Piezoelectric device 10 Piezoelectric vibration element 11 Piezoelectric piece 111 Through hole 112 Wall conductor 12 Excitation electrode 13 Mounting electrode 13r Intermediate electrode 14 Lead wire 15 Reinforcing member 20 Package 20a Recess 21 Housing 211 Substrate 212 Frame 22 Connection electrode 23 External electrode 30 Lid 40 Joining member

Claims

1. A piezoelectric vibration element comprising: a plate-shaped piezoelectric piece having a first surface and a second surface opposite the first surface; two excitation electrodes located on the first surface and the second surface, respectively; two mounting electrodes electrically connected to the excitation electrodes on the first surface and the second surface, respectively; and a reinforcing member reinforcing the mounting electrodes, wherein the piezoelectric piece has a through hole overlapping the mounting electrode located on the first surface in a planar view and extending between the first surface and the second surface, and a conductive layer connected to the mounting electrode on the first surface and extending between the first surface and the second surface along the inner wall surface of the through hole, wherein the reinforcing member is located on the first surface so as to overlap at least a portion of the through hole, has a thickness of 2 μm or less along the extension direction of the through hole, and is an insulator or a semiconductor.

2. The piezoelectric vibration element according to claim 1, wherein the mounting electrode is located between the reinforcing member and the through hole.

3. The piezoelectric vibration element according to claim 1 or 2, wherein the reinforcing member overlaps the entire through hole in a plan view.

4. A piezoelectric vibration element according to any one of claims 1 to 3, wherein the planar range of the reinforcing member is included in the planar range of the mounting electrode on the first surface.

5. A piezoelectric vibration element as described in any one of claims 1 to 4, comprising an intermediate electrode located on the second surface and connected to the mounting electrode on the first surface via the conductive layer, the intermediate electrode being in an area that overlaps with the mounting electrode in a planar view.

6. The piezoelectric vibration element according to any one of claims 1 to 5, wherein the insulator or semiconductor contains silicon.

7. A piezoelectric device comprising: a piezoelectric vibration element according to any one of claims 1 to 6; and a package having a recess for accommodating the piezoelectric vibration element, wherein the piezoelectric vibration element is bonded to the bottom surface of the recess with a conductive bonding material.

8. The piezoelectric device according to claim 7, wherein a portion of the conductive bonding material is located within the through hole.

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