Vibration element and vibration device

Abstract

To provide a vibration element and a vibration device with excellent bonding strength.SOLUTION: A vibration element 1 includes a substrate 10 with a thin part 11 and a thick part 12, and an electrode part 30 including excitation electrodes 31 and 32, pad electrodes 33 and 34, and extraction electrodes 35 and 36. The electrode part 30 includes a first electrode layer 41 arranged in a pad electrode arrangement region 14 and a first region 16 on the substrate 10, a second electrode layer 42 arranged in a region overlapping with the first electrode layer 41 on the first electrode layer 41 and having larger thickness than the first electrode layer 41, a third electrode layer 43 arranged across a region overlapping with the pad electrode arrangement region 14 and the first region 16 in a plan view on the second electrode layer 42 and a region overlapping with the second region 17 and the excitation electrode arrangement region 13 in a plan view on the substrate 10 and having smaller thickness than the second electrode layer 42, and a fourth electrode layer 44 arranged in a region overlapping with the third electrode layer 43 on the third electrode layer 43 and having smaller thickness than the second electrode layer 42.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a vibration element and a vibration device. [Background technology]

[0002] Patent Document 1 discloses a piezoelectric vibration element with a so-called inverted mesa structure in which a recess is formed in a part of the main surface to increase the frequency. This piezoelectric vibration element has a slit between the thick part that fixes the piezoelectric vibration element and the vibration part to suppress the spread of stress caused by adhesion and fixation. In addition, due to the thinning of the electrodes accompanying the increase in frequency, the thickness of the extraction electrode is made thicker than the thickness of the excitation electrode to prevent an increase in sheet resistance, particularly in the narrow extraction electrode that electrically connects the excitation electrode and the pad electrode. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-7693 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the piezoelectric vibration element of Patent Document 1, a bonding material that mechanically and electrically connects the piezoelectric vibration element to a package is bonded to a pad electrode. Therefore, if the thickness of the pad electrode is insufficient, the bonding strength between the piezoelectric vibration element and the bonding material cannot be obtained, resulting in an unstable mechanical connection or electrical connection between the piezoelectric vibration element and the package. [Means for solving the problem]

[0005] The vibration element includes a substrate including a thin portion and a thick portion having a thickness greater than that of the thin portion, and an electrode portion including an excitation electrode arranged in an excitation electrode arrangement region of the thin portion, a pad electrode arranged in a pad electrode arrangement region of the thick portion, and an extraction electrode that connects the excitation electrode and the pad electrode and is arranged in an extraction electrode arrangement region of the substrate, the extraction electrode arrangement region including a first region including a portion located in the thick portion and a second region including a portion located in the thin portion, and the electrode portion includes a first electrode layer arranged in the pad electrode arrangement region and the first region on the substrate, a second electrode layer arranged in a region overlapping with the pad electrode arrangement region and the first region in a planar view and having a thickness greater than that of the first electrode layer; a third electrode layer arranged on the second electrode layer across the region overlapping with the pad electrode arrangement region and the first region in a planar view and across the region overlapping with the second region and the excitation electrode arrangement region on the substrate in a planar view and having a thickness smaller than that of the second electrode layer; and a fourth electrode layer arranged on the third electrode layer across the regions overlapping with the pad electrode arrangement region, the extraction electrode arrangement region, and the excitation electrode arrangement region in a planar view and having a thickness smaller than that of the second electrode layer.

[0006] The vibration device includes the vibration element described above, and a package that houses the vibration element and to which the vibration element is fixed via a bonding material. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a perspective view showing a configuration of a vibration element according to a first embodiment. [Diagram 2] 1 is a diagram explaining the relationship between an AT-cut quartz crystal substrate and the crystal axes of quartz crystal. [Diagram 3] FIG. 2 is a plan view of the vibration element shown in FIG. [Figure 4] Cross-sectional view taken along line A1-A1 in FIG. 3. [Diagram 5] Cross-sectional view taken along line A2-A2 in Figure 3. [Figure 6] Cross-sectional view taken along line A3-A3 in Figure 3. [Figure 7]FIG. 11 is a plan view showing the configuration of a vibration element according to a second embodiment. [Figure 8] Cross-sectional view taken along line B1-B1 in FIG. 7. [Figure 9] FIG. 11 is a perspective view showing the configuration of a vibration element according to a third embodiment. [Figure 10] FIG. 13 is a cross-sectional view showing the configuration of a vibration device according to a fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] 1. First embodiment 1.1.Vibration element A vibration element 1 according to a first embodiment will be described with reference to FIGS.

[0009] For ease of explanation, in each of the subsequent figures except for FIG. 2, the X-axis, Y'-axis, and Z'-axis are illustrated as three mutually orthogonal axes. The longitudinal direction of the vibration element 1 is referred to as the "X-direction" along the X-axis, the thickness direction of the vibration element 1 is referred to as the "Y'-direction" along the Y'-axis, and the direction perpendicular to the X-axis and Y'-axis is referred to as the "Z'-direction" along the Z'-axis. The arrow side of each axis is also referred to as the "plus side," and the opposite side to the arrow is also referred to as the "minus side." The plus side of the Y' direction is also referred to as the "front," and the minus side of the Y' direction is also referred to as the "back."

[0010] As shown in FIG. 1, the vibration element 1 of this embodiment has a substrate 10 and an electrode portion 30 formed on the substrate 10.

[0011] The substrate 10 is a plate-shaped quartz substrate. Here, the quartz, which is the material of the substrate 10, belongs to the trigonal crystal system and has crystal axes X, Y, and Z that are perpendicular to each other as shown in FIG. 2. The X-axis, Y-axis, and Z-axis are called the electrical axis, mechanical axis, and optical axis, respectively. The substrate 10 of this embodiment is a "rotated Y-cut quartz substrate" cut along a plane obtained by rotating the XZ plane by a predetermined angle θ around the X-axis. For example, a substrate cut along a plane rotated by θ=35°15' is called an "AT-cut quartz substrate". By using such a quartz substrate, the vibration element 1 has excellent temperature characteristics.

[0012] However, the substrate 10 is not limited to an AT-cut quartz substrate, and may be, for example, a BT-cut quartz substrate, as long as it can excite thickness-shear vibration. In addition to a quartz substrate, the substrate 10 may be any of various piezoelectric substrates, such as lithium niobate and lithium tantalate. In the following description, the Y axis and the Z axis rotated around the X axis corresponding to the angle θ are defined as the Y' axis and the Z' axis. That is, the substrate 10 has a thickness in the Y' direction and an extent in the XZ' plane direction.

[0013] Substrate 10 has a longitudinal shape with its long side in the X direction and its short side in the Z' direction in plan view. Substrate 10 has its tip side in the negative X direction and its base side in the positive X direction. When substrate 10 has its maximum length in the X direction as L and its maximum width in the Z' direction as W, L / W is not particularly limited, but is preferably, for example, about 1.1 to 1.4.

[0014] As shown in Figures 1 and 3, the substrate 10 has a thin portion 11 in a vibration area where vibration energy is trapped, and a thick portion 12 that is integrated with the thin portion 11 and is thicker than the thin portion 11. The thin portion 11 is biased toward the negative side in the X direction and the negative side in the Z' direction with respect to the center of the substrate 10, and a part of its outer edge is exposed from the thick portion 12. In a plan view of the vibration element 1, the area of ​​the thin portion 11 is preferably equal to or less than half the area of ​​the substrate 10. This allows the thick portion 12, which has high mechanical strength, to be formed sufficiently wide, thereby ensuring sufficient rigidity of the thin portion 11.

[0015] In a plan view of the vibration element 1, the thin-walled portion 11 has a first outer edge 21 and a second outer edge 22 that are spaced apart in the X direction, which is the vibration direction of thickness-shear vibration, and extend in the Z' direction, and a third outer edge 23 and a fourth outer edge 24 that are spaced apart in the Z' direction and extend in the X direction. Of the first outer edge 21 and the second outer edge 22, the first outer edge 21 is located on the positive side of the X direction, and the second outer edge 22 is located on the negative side of the X direction. Also, of the third outer edge 23 and the fourth outer edge 24, the third outer edge 23 is located on the positive side of the Z' direction, and the fourth outer edge 24 is located on the negative side of the Z' direction. Also, the third outer edge 23 connects the ends of the first outer edge 21 and the second outer edge 22 on the positive side of the Z' direction, and the fourth outer edge 24 connects the ends of the first outer edge 21 and the second outer edge 22 on the negative side of the Z' direction.

[0016] 1, the front surface which is the main surface of the thick portion 12 on the positive side in the Y' direction protrudes further toward the positive side in the Y' direction than the front surface which is the main surface of the thin portion 11 on the positive side in the Y' direction. On the other hand, the back surface which is the main surface of the thick portion 12 on the negative side in the Y' direction is provided on the same plane as the back surface which is the main surface of the thin portion 11 on the negative side in the Y' direction.

[0017] The thick portion 12 has a thick portion 12 arranged along the first outer edge 21 and a thick portion 12 arranged along the third outer edge 23. Therefore, the thick portion 12 has a structure bent along the thin portion 11 in a plan view, and is approximately L-shaped. On the other hand, the thick portion 12 is not formed on the second outer edge 22 and the fourth outer edge 24 of the thin portion 11, and these second outer edge 22 and the fourth outer edge 24 are exposed from the thick portion 12. In this way, the thick portion 12 is partially provided on the outer edge of the thin portion 11 to form an approximately L shape, and is not provided along the second outer edge 22 and the fourth outer edge 24, so that the mass of the tip side of the vibration element 1 can be reduced while maintaining the rigidity of the thin portion 11 of the vibration element 1. In addition, the vibration element 1 can be made smaller in size.

[0018] The thick portion 12 includes a connection portion 26 that is connected to the first outer edge 21 and has a sloped portion whose thickness gradually increases in the positive X direction, and a connection portion 25 that is connected to the third outer edge 23 and has a sloped portion whose thickness gradually increases in the positive Z' direction, which connects between the thick portion 12 and the thin portion 11. The thick portion 12 on the connection portion 26 side serves as a mount portion, and is fixed to a package or the like using a conductive adhesive or the like.

[0019] The electrode section 30 has a pair of excitation electrodes 31 and 32, a pair of pad electrodes 33 and 34, and a pair of extraction electrodes 35 and 36.

[0020] The excitation electrodes 31 and 32 are arranged in the excitation electrode arrangement region 13 of the thin portion 11. The excitation electrode 31 is formed on the front surface of the thin portion 11. On the other hand, the excitation electrode 32 is arranged on the rear surface of the thin portion 11 so as to face the excitation electrode 31. Each of the excitation electrodes 31 and 32 has a substantially rectangular shape with the X direction as the long side and the Z' direction as the short side.

[0021] The pad electrodes 33 and 34 are arranged in the pad electrode arrangement region 14 of the thick portion 12. The pad electrode 33 is formed on the front surface of the thick portion 12 on the connection portion 26 side. On the other hand, the pad electrode 34 is formed opposite the pad electrode 33 on the back surface of the thick portion 12 on the connection portion 26 side.

[0022] The lead electrodes 35, 36 are arranged in a lead electrode arrangement region 15 of the substrate 10. The lead electrode arrangement region 15 is composed of a first region 16 including a portion located in the thick portion 12 including the connection portions 25, 26, and a second region 17 including a portion located in the thin portion 11. The lead electrode 35 electrically connects the excitation electrode 31 and the pad electrode 33. On the other hand, the lead electrode 36 electrically connects the excitation electrode 32 and the pad electrode 34. The lead electrodes 35, 36 are provided so as not to overlap with each other via the substrate 10. This makes it possible to suppress the electrostatic capacitance between the lead electrodes 35, 36.

[0023] As shown in Figures 3, 4, 5, and 6, the electrode section 30 is composed of pad electrodes 33, 34 and parts of extraction electrodes 35, 36, which are formed by stacking four layers of metal, namely, a first electrode layer 41, a second electrode layer 42, a third electrode layer 43, and a fourth electrode layer 44, and excitation electrodes 31, 32 and parts of extraction electrodes 35, 36, which are formed by stacking two layers of metal, namely, the third electrode layer 43 and the fourth electrode layer 44.

[0024] Specifically, the first electrode layer 41 is disposed in the pad electrode arrangement region 14 and the first region 16 on the substrate 10. The second electrode layer 42 is disposed on the first electrode layer 41 in a region overlapping the pad electrode arrangement region 14 and the first region 16 in a planar view. The thickness t2 of the second electrode layer 42 is greater than the thickness t1 of the first electrode layer 41. In addition, in terms of controlling an increase in sheet resistance, it is more preferable that the thickness t2 of the second electrode layer 42 is three times or more the thickness t4 of the fourth electrode layer 44.

[0025] The third electrode layer 43 is disposed on the second electrode layer 42 across a region overlapping with the pad electrode arrangement region 14 and the first region 16 in a planar view, and a region overlapping with the second region 17 and the excitation electrode arrangement region 13 on the substrate 10 in a planar view. The thickness t3 of the third electrode layer 43 is smaller than the thickness t2 of the second electrode layer 42.

[0026] The fourth electrode layer 44 is disposed on the third electrode layer 43 across an area overlapping with the pad electrode arrangement area 14, the extraction electrode arrangement area 15, and the excitation electrode arrangement area 13 in a plan view. The thickness t4 of the fourth electrode layer 44 is smaller than the thickness t2 of the second electrode layer 42.

[0027] The constituent materials of the electrode portion 30 are gold (Au) for the second electrode layer 42 and the fourth electrode layer 44, and at least one of nickel (Ni), chromium (Cr), and chromium nitride (CrN) for the first electrode layer 41 and the third electrode layer 43.

[0028] As described above, in the vibration element 1 of this embodiment, the pad electrodes 33, 34 and the extraction electrodes 35, 36 having a four-layer structure are provided on the thick portion 12 including the connection portions 25, 26 of the substrate 10, and the excitation electrodes 31, 32 and the extraction electrodes 35, 36 having a two-layer structure are provided on the thin portion 11. Therefore, the thickness of the excitation electrodes 31, 32 can be set to a thickness that does not easily cause unnecessary spurious, the thickness of the extraction electrodes 35, 36 can be set to a thickness that does not easily increase the sheet resistance, and the thickness of the pad electrodes 33, 34 can be set to a thickness that provides sufficient bonding strength. Therefore, it is possible to obtain a vibration element 1 having excellent vibration characteristics and excellent mechanical or electrical reliability.

[0029] 1.2. Manufacturing method of vibration element Next, a method for manufacturing the vibration element 1 will be described. The manufacturing method of the vibration element 1 includes a thin-walled portion forming process for thinning a portion of the substrate 10, a first electrode portion forming process for forming an electrode on the substrate 10, and a second electrode portion forming process for forming electrodes on the first electrode portion and the thin-walled portion.

[0030] 1.2.1. Thin section forming process An etching protection film of gold (Au) or the like is formed by a film forming device such as a sputtering device on the front and back surfaces of the substrate 10. Next, a protection film mask for forming recesses on the surface of the substrate 10 is formed by using photolithography and etching techniques.

[0031] Next, the substrate 10 is wet-etched using an etching solution, for example, a mixed solution of hydrofluoric acid and ammonium fluoride, through the protective film mask, to form the thin portion 11 in the substrate 10.

[0032] 1.2.2. First electrode part forming process A first electrode layer 41 such as chromium (Cr) and a second electrode layer 42 such as gold (Au) are laminated on the front and back surfaces of the substrate 10 on which the thin portion 11 is formed, using a film forming device such as sputtering. Thereafter, the pad electrodes 33, 34 and the lead electrodes 35, 36 are formed in the pad electrode arrangement region 14 and the first region 16 of the lead electrode arrangement region 15 on the substrate 10 using photolithography and etching techniques.

[0033] 1.2.3. Second electrode part forming process A third electrode layer 43 such as chromium (Cr) and a fourth electrode layer 44 such as gold (Au) are laminated by a film forming device such as sputtering on the front and back surfaces of the substrate 10 on which the pad electrodes 33, 34 and the extraction electrodes 35, 36 are formed in the pad electrode arrangement region 14 and the first region 16 of the extraction electrode arrangement region 15. Thereafter, the pad electrodes 33, 34, the extraction electrodes 35, 36, and the excitation electrodes 31, 32 are formed by using photolithography and etching techniques in the regions on the second electrode layer 42 that overlap with the pad electrode arrangement region 14 and the first region 16 of the extraction electrode arrangement region 15, and in the second region 17 of the extraction electrode arrangement region 15 on the substrate 10 and the excitation electrode arrangement region 13.

[0034] By the above manufacturing method, it is possible to manufacture a vibration element 1 in which the pad electrodes 33, 34 and the extraction electrodes 35, 36 of a four-layer structure are provided on the thick portion 12 including the connection portions 25, 26 of the substrate 10, and the excitation electrodes 31, 32 and the extraction electrodes 35, 36 of a two-layer structure are provided on the thin portion 11. Therefore, it is possible to make the thickness of the excitation electrodes 31, 32 thin enough to prevent unnecessary spurious from occurring, the thickness of the extraction electrodes 35, 36 thick enough to prevent sheet resistance from increasing, and the thickness of the pad electrodes 33, 34 thick enough to obtain sufficient bonding strength. Therefore, it is possible to obtain a vibration element 1 with excellent vibration characteristics and excellent mechanical or electrical reliability.

[0035] 2. Second embodiment 2.1.Vibration element Next, a vibration element 1a according to a second embodiment will be described with reference to FIGS.

[0036] The vibration element 1a of this embodiment is similar to the vibration element 1 of the first embodiment, except that the arrangement and configuration of the electrode parts 30a is different from that of the vibration element 1 of the first embodiment. Note that the following description will focus on the differences from the first embodiment described above, and similar items are denoted by the same reference numerals and their description will be omitted.

[0037] The vibration element 1a has a substrate 10 and an electrode portion 30a formed on the substrate 10, as shown in FIG.

[0038] The electrode section 30a of the vibration element 1a is composed of pad electrodes 33, 34 having a four-layer structure, lead electrodes 35a, 36a having a four-layer structure and a two-layer structure, and excitation electrodes 31, 32 having a two-layer structure. The first region 16a of the lead electrode arrangement region 15a in which the lead electrodes 35a, 36a having a four-layer structure are formed also includes a portion located in the thin portion 11. That is, as shown in FIG. 8, the lead electrode 35a having a four-layer structure is formed in the thick portion 12 including the connection portion 25 and in a part of the thin portion 11.

[0039] With this configuration, the vibration element 1a can shorten the two-layered extraction electrodes 35a and 36a, and the increase in sheet resistance can be further suppressed, resulting in a vibration element 1a with excellent bonding strength and a low CI value.

[0040] 3. Third embodiment 3.1.Vibration element Next, a vibration element 1b according to a third embodiment will be described with reference to FIG.

[0041] The vibration element 1b of this embodiment is similar to the vibration element 1 of the first embodiment, except that the shape of the substrate 10b is different from that of the vibration element 1 of the first embodiment. Note that the following description will focus on the differences from the first embodiment described above, and similar items are denoted by the same reference numerals and their description will be omitted.

[0042] As shown in FIG. 9, the vibration element 1b has a substrate 10b and an electrode portion 30 formed on the substrate 10b.

[0043] In the substrate 10b of the vibration element 1b, the front surface, which is the main surface of the thick portion 12 on the positive side in the Y' direction, is provided so as to protrude toward the positive side in the Y' direction from the front surface, which is the main surface of the thin portion 11b on the positive side in the Y' direction. On the other hand, the back surface, which is the main surface of the thick portion 12 on the negative side in the Y' direction, is provided so as to protrude toward the negative side in the Y' direction from the back surface, which is the main surface of the thin portion 11b on the negative side in the Y' direction. In other words, the thin portion 11b is formed by forming recesses on the front and back surfaces of the substrate 10b. Therefore, in the manufacturing method, the etching depth of the recesses can be made shallower than in the first embodiment described above, and the cost can be reduced.

[0044] With this configuration, the vibration element 1b has excellent bonding strength, and the vibration element 1b can be obtained at low cost.

[0045] 4. Fourth embodiment 4.1.Vibration Device Next, a vibration device 2 according to a fourth embodiment will be described with reference to Fig. 10. In this description, the vibration device 2 including the vibration element 1 described above will be taken as an example.

[0046] As shown in FIG. 10, the vibration device 2 includes a vibration element 1, a package 50 that accommodates the vibration element 1, and a lid 60 that forms an accommodation space 52 with the package 50.

[0047] The package 50 has a recess 51 that opens to a first surface 55, and a lid 60 that closes the opening of the recess 51 is bonded to the first surface 55. By closing the recess 51 of the package 50 with the lid 60, an accommodation space 52 that accommodates the vibration element 1 is formed. The accommodation space 52 may be in a reduced pressure or vacuum state, or may be filled with an inert gas such as nitrogen (Ni), helium (He), or argon (Ar).

[0048] The material of the package 50 is not particularly limited, but various ceramics such as aluminum oxide can be used. The material of the lid 60 is not particularly limited, but it is preferable that the material has a linear expansion coefficient similar to that of the material of the package 50. The method of joining the package 50 and the lid 60 is not particularly limited, and they may be joined, for example, via an adhesive or by seam welding.

[0049] Connection electrodes 56 and 57 are formed on an inner bottom surface 53 of the package 50. In addition, external mounting terminals 58 and 59 are formed on a second surface 54 of the package 50. The connection electrode 56 is electrically connected to the external mounting terminal 58 via a through electrode (not shown) formed in the package 50, and the connection electrode 57 is electrically connected to the external mounting terminal 59 via a through electrode (not shown) formed in the package 50.

[0050] The vibration element 1 accommodated in the accommodation space 52 is fixed to the package 50 at a mount portion of the thick portion 12 by a bonding material 61, which is a conductive adhesive, with the surface, which is the main surface on the Y' direction positive side of the thick portion 12, facing the package 50. The bonding material 61 is provided in contact with the connection electrode 56 and the pad electrode 33. This allows the connection electrode 56 and the pad electrode 33 to be electrically connected via the bonding material 61. By supporting the vibration element 1 at one place or at one point using the bonding material 61, for example, it is possible to suppress stress generated in the vibration element 1 due to the difference in thermal expansion coefficient between the package 50 and the substrate 10.

[0051] The pad electrode 34 of the vibration element 1 is electrically connected to the connection electrode 57 via the bonding wire 62. As described above, the pad electrode 34 is disposed opposite the pad electrode 33, and is therefore located directly above the bonding material 61 when the vibration element 1 is fixed to the package 50. This makes it possible to suppress leakage of ultrasonic vibration applied to the pad electrode 34 during wire bonding, and makes it possible to more reliably connect the bonding wire 62 to the pad electrode 34.

[0052] Moreover, the pad electrodes 33, 34 have a four-layer structure and are sufficiently thick. Therefore, it is possible to ensure sufficient bonding strength with the bonding material 61 and bonding strength with the bonding wire 62. Therefore, the vibration device 2 in which the vibration element 1 provided with the pad electrodes 33, 34 having sufficient bonding strength is fixed in the package 50 has excellent mechanical reliability and electrical reliability.

[0053] With this configuration, the vibration device 2 includes a vibration element 1 in which the excitation electrodes 31, 32 are thin enough to prevent unnecessary spurious responses, the extraction electrodes 35, 36 are thick enough to prevent an increase in sheet resistance, and the pad electrodes 33, 34 are thick enough to provide sufficient bonding strength, so that a vibration device 2 having good vibration characteristics and excellent mechanical and electrical reliability can be obtained. [Explanation of symbols]

[0054] Reference Signs List 1, 1a, 1b... vibration element, 2... vibration device, 10... substrate, 11... thin portion, 12... thick portion, 13... excitation electrode arrangement area, 14... pad electrode arrangement area, 15... extraction electrode arrangement area, 16... first area, 17... second area, 21... first outer edge, 22... second outer edge, 23... third outer edge, 24... fourth outer edge, 25, 26... connection portion, 30... electrode portion, 31, 32... excitation electrode, 33, 34... pad electrode, 35 ,36...extraction electrode, 41...first electrode layer, 42...second electrode layer, 43...third electrode layer, 44...fourth electrode layer, 50...package, 51...recess, 52...accommodation space, 53...inner bottom surface, 54...second surface, 55...first surface, 56, 57...connection electrode, 58, 59...external mounting terminal, 60...lid, 61...bonding material, 62...bonding wire, t1, t2, t3, t4...thickness, L...maximum length, W...maximum width.

Claims

1. a substrate including a thin portion and a thick portion having a thickness greater than that of the thin portion; an electrode section including: an excitation electrode arranged in an excitation electrode arrangement region of the thin portion; a pad electrode arranged in a pad electrode arrangement region of the thick portion; and an extraction electrode connecting the excitation electrode and the pad electrode and arranged in an extraction electrode arrangement region of the substrate; Equipped with the extraction electrode arrangement region includes a first region including a portion located in the thick portion and a second region including a portion located in the thin portion, The electrode portion is a first electrode layer disposed in the pad electrode arrangement region and the first region on the substrate; a second electrode layer disposed on the first electrode layer in a region overlapping the pad electrode arrangement region and the first region in a plan view, the second electrode layer having a thickness greater than that of the first electrode layer; a third electrode layer that is disposed on the second electrode layer across a region that overlaps with the pad electrode arrangement region and the first region in a planar view and a region that overlaps with the second region and the excitation electrode arrangement region on the substrate in a planar view, and has a thickness smaller than that of the second electrode layer; a fourth electrode layer disposed on the third electrode layer across an area overlapping the pad electrode arrangement area, the extraction electrode arrangement area, and the excitation electrode arrangement area in a plan view, the fourth electrode layer having a thickness smaller than that of the second electrode layer; Vibration element.

2. The thickness of the second electrode layer is three times or more the thickness of the fourth electrode layer. The vibration element according to claim 1 .

3. The first region includes a portion located in the thin portion. The vibration element according to claim 1 .

4. The first region includes a portion located in the thin portion. The vibration element according to claim 2 .

5. the substrate includes a connection portion that connects the thick portion and the thin portion and has an inclined portion; The first region includes a portion located at the thin portion and the connection portion in a plan view. The vibration element according to claim 1 .

6. the second electrode layer and the fourth electrode layer are gold; the first electrode layer and the third electrode layer include at least one of nickel, chromium, and chromium nitride; The vibration element according to claim 1 .

7. the second electrode layer and the fourth electrode layer are gold; the first electrode layer and the third electrode layer include at least one of nickel, chromium, and chromium nitride; The vibration element according to claim 5 .

8. The vibration element according to any one of claims 1 to 4, a package that houses the vibration element and to which the vibration element is fixed via a bonding material; Equipped with Vibration devices.

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