Vibration device

Abstract

To provide a vibration device capable of suppressing a contact with a lid.SOLUTION: A vibration device comprises: a base substrate having a first surface and a second surface that have a front-rear relation; a vibration element that is mounted on the first surface side of the base substrate; and a concave part that opens toward the base substrate side, and includes a lid bonded to the first surface side in a state of housing the vibration element in the concave part. The lid includes: a bottom part; and a frame-like side wall part erected toward the base substrate side from an outer edge part of the bottom part. An inner peripheral surface of the side wall part includes a first inclination part that is inclined so as to be separated away from a first virtual center line passing through a center of the lid as proceeding in a direction of the base substrate side from the bottom part side. The vibration element includes a first side that is opposite to the first inclination part in a plane view; a second side along a direction crossing the first side; a first angle part positioned between the first side and the second side; a third side positioned on a side opposite to the second side; and a second angle part positioned between the first side and the third side. Both of the first angle part and the second angle part are each notched.SELECTED DRAWING: Figure 4

Description

[Technical field]

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

[0002] Patent Document 1 discloses a vibration device having a package and a vibration element housed in the package. The package has a plate-shaped base substrate on whose upper surface the vibration element is mounted, and a box-shaped lid having a recess that opens toward the base substrate and is joined to the upper surface of the base substrate with the vibration element housed in the recess. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-123928 A Summary of the Invention [Problem to be solved by the invention]

[0004] Here, if the lid is made of a material such as quartz or silicon whose etching rate varies depending on the crystal plane, and the recess is formed by wet etching, the inner circumferential surface of the recess will be inclined from the bottom of the lid toward the base substrate so as to move away from the center. As a result, the gap between the inner surface of the recess and the vibration element will be narrowed, and there is a risk that the vibration element will come into contact with the inner circumferential surface of the recess. [Means for solving the problem]

[0005] The vibration device according to the present invention includes a base substrate having a first surface and a second surface that are reversed to each other; A vibration element mounted on the first surface side of the base substrate; a cover body that is joined to the first surface side and has a recess that opens to the base substrate side and accommodates the vibration element in the recess, the lid body has a bottom portion and a frame-shaped side wall portion extending from an outer edge portion of the bottom portion toward the base substrate side, an inner circumferential surface of the side wall portion has a first inclined portion that is inclined from the bottom side toward the base substrate side so as to move away from a first imaginary center line that passes through a center of the lid body in a plan view and is perpendicular to a surface of the lid body opposite to the recessed portion; In a planar view, the vibration element has a first side opposite the first inclined portion, a second side along a direction intersecting the first side, a first corner between the first side and the second side, a third side along a direction intersecting the first side and positioned opposite the second side, and a second corner between the first side and the third side, and the first corner and the second corner are each cut out. [Brief description of the drawings]

[0006] [Figure 1] 1 is a cross-sectional view showing a vibration device according to a first embodiment. [Diagram 2] 2 is a top view of the vibration device shown in FIG. 1. [Diagram 3] FIG. 2 is a top view showing the vibration element. [Figure 4] FIG. 2 is a top view showing the vibration element. [Diagram 5] FIG. 11 is a top view showing a state in which the vibration element is mounted in a misaligned state. [Figure 6] 10 is a top view showing a vibration element of a vibration device according to a second embodiment. FIG. [Figure 7] 13 is a top view showing a vibration element of a vibration device according to a third embodiment. FIG. [Figure 8] 13 is a top view showing a vibration element of a vibration device according to a third embodiment. FIG. [Figure 9] 13 is a top view showing a vibration element of a vibration device according to a fourth embodiment. FIG. [Figure 10] FIG. 13 is a cross-sectional view showing a vibration device according to a fifth embodiment. [Figure 11] FIG. 11 is a cross-sectional view showing a modified example of the vibration device. [Figure 12]FIG. 11 is a cross-sectional view showing a modified example of the vibration device. [Figure 13] FIG. 13 is a cross-sectional view showing a vibration device according to a sixth embodiment. [Figure 14] FIG. 13 is a cross-sectional view showing a vibration device according to a seventh embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a vibration device according to the present invention will be described in detail based on embodiments shown in the accompanying drawings.

[0008] First Embodiment FIG. 1 is a cross-sectional view showing a vibration device according to a first embodiment. FIG. 2 is a top view of the vibration device shown in FIG. 1. FIGS. 3 and 4 are top views showing a vibration element. FIG. 5 is a top view showing a state in which the vibration element is mounted in a misaligned state. For convenience of explanation, each figure shows an X-axis, a Y-axis, and a Z-axis that are orthogonal to each other. The arrow side of each axis is also called the "plus side", and the opposite side is also called the "minus side". The plus side in the Z-axis direction is also called the "upper side", and the minus side is also called the "lower side". The plus side in the X-axis direction is also called the "tip side", and the minus side is also called the "base side". The planar view from the Z-axis direction is also simply called the "planar view".

[0009] The resonator device 1 shown in Fig. 1 is an oscillator. The resonator device 1 includes a base substrate 2, a resonator element 3 that is a functional element arranged on the upper surface 2a of the base substrate 2, bonding members B1 and B2 that bond the resonator element 3 to the base substrate 2, a lid 4 that covers the resonator element 3 and is bonded to the upper surface 2a of the base substrate 2, and an oscillator circuit 6 that is arranged on the lower surface 2b of the base substrate 2. In the resonator device 1, the resonator element 3 is accommodated in an accommodation space S of a package P formed by the base substrate 2 and the lid 4.

[0010] The base substrate 2 is a semiconductor substrate, particularly a silicon substrate. However, the base substrate 2 is not particularly limited, and may be, for example, a substrate made of a semiconductor material other than silicon, such as Ge, GaP, GaAs, or InP. The base substrate 2 may also be made of a material other than a semiconductor material, such as quartz, a glass material, or a ceramic material.

[0011] The base substrate 2 has an upper surface 2a as a first surface and a lower surface 2b as a second surface, which are opposite surfaces. The base substrate 2 has a pair of through holes 21, 22 that penetrate the upper surface 2a and the lower surface 2b. The surface of the base substrate 2 is covered with an insulating layer 20. The insulating layer 20 is made of, for example, silicon oxide (SiO 2 The insulating layer 20 can be formed by, for example, sputtering or CVD (Chemical Vapor Deposition). However, the constituent material and the method of forming the insulating layer 20 are not particularly limited.

[0012] In addition, an oscillator circuit 6 electrically connected to the vibration element 3 is formed on the lower surface 2b side of the base substrate 2. The oscillator circuit 6 oscillates the vibration element 3 to generate a frequency of a reference signal such as a clock signal. This makes the vibration device 1 an oscillator, which is expected to be highly versatile and in demand.

[0013] The oscillator circuit 6 also includes a plurality of elements 60 such as transistors formed on the lower surface 2b of the base substrate 2, an insulating layer 61 laminated on the lower surface 2b, a wiring layer 62 laminated on the lower surface of the insulating layer 61, an insulating layer 63 laminated on the lower surface of the wiring layer 62, a passivation film 64 laminated on the lower surface of the insulating layer 63, and a terminal layer 65 laminated on the lower surface of the passivation film 64. The oscillator circuit 6 is configured by electrically connecting the plurality of elements 60 together via the wiring included in the wiring layer 62 and through electrodes penetrating between layers.

[0014] In this way, by forming the oscillation circuit 6 on the base substrate 2, the free space of the base substrate 2 can be effectively utilized. In particular, by forming the oscillation circuit 6 on the lower surface 2b side, the area where the oscillation circuit 6 can be formed is wider than the case where the oscillation circuit 6 is formed on the upper surface 2a side because there is no bonding area with the lid body 4. Therefore, the design freedom of the oscillation circuit 6 is increased. In this embodiment, the oscillation circuit 6 includes one wiring layer 62, but this is not limited thereto, and multiple wiring layers 62 may be laminated via an insulating layer 63. In other words, the wiring layer 62 and the insulating layer 63 may be alternately laminated multiple times between the insulating layer 61 and the passivation film 64. This improves the freedom of wiring and makes it easier to design the circuit.

[0015] Further, through holes 611 and 612 are formed in the insulating layer 61, penetrating the upper surface and the lower surface. The through hole 611 is connected to the through hole 21. Hereinafter, the through hole formed by the through hole 21 and the through hole 611 communicating with each other and penetrating from the upper surface 2a to the lower surface of the insulating layer 61 is also referred to as the "through hole H1". Similarly, the through hole 612 is connected to the through hole 22. Hereinafter, the through hole formed by the through hole 22 and the through hole 612 communicating with each other and penetrating from the upper surface 2a to the lower surface of the insulating layer 61 is also referred to as the "through hole H2".

[0016] The wiring layer 62 has an electrode pad 621 that overlaps the through hole H1 and is exposed in the through hole H1, and an electrode pad 622 that overlaps the through hole H2 and is exposed in the through hole H2. The terminal layer 65 has a plurality of external terminals 651 for connecting the oscillator circuit 6 to an external device. Each external terminal 651 penetrates the insulating layer 63 and the passivation film 64 and is electrically connected to the wiring layer 62.

[0017] The base substrate 2 also has a wiring layer 71 electrically connected to the electrode pad 621 from the upper surface 2a side of the base substrate 2 through the through hole H1, and a wiring layer 72 electrically connected to the electrode pad 622 from the upper surface 2a side of the base substrate 2 through the through hole H2.

[0018] As shown in FIG. 1, the lid 4 has a bottomed recess 41 that opens to the bottom and accommodates the vibration element 3 therein. Therefore, the lid 4 has a plate-shaped bottom 4a and a frame-shaped side wall 4b that stands downward from the outer edge of the bottom 4a. The lid 4 is joined to the upper surface of the base substrate 2 via a joining member at its bottom surface. As a result, a storage space S that accommodates the vibration element 3 is formed between the lid 4 and the base substrate 2, and the vibration element 3 is protected. The storage space S is airtight and in a reduced pressure state, preferably in a state closer to a vacuum. This reduces viscous resistance and improves the oscillation characteristics of the vibration element 3. However, the atmosphere of the storage space S is not particularly limited.

[0019] The recess 41 is formed by wet etching. That is, the inner peripheral surface of the recess 41 is a wet-etched surface. By forming the recess 41 by wet etching, the inner peripheral surface of the recess 41 becomes an inclined portion that inclines from the bottom 4a side toward the base substrate 2 side so as to move away from a first imaginary center line C1 that passes through a center O1 of the lid 4 in a plan view and is perpendicular to a surface 42 of the lid 4 opposite to the recess 41. The center O1 of the lid 4 in a plan view is the center of the lid 4 in the X-axis direction and the Y-axis direction. 2, in this embodiment, the shape of the recess 41 in plan view is rectangular, so the inclined portion has a first inclined portion 431 located on the positive side of the X axis direction and configured with a YZ plane inclined about the Y axis, a second inclined portion 432 located on the negative side of the X axis direction and configured with a YZ plane inclined about the Y axis, a third inclined portion 433 located on the positive side of the Y axis direction and configured with an XZ plane inclined about the X axis, and a fourth inclined portion 434 located on the negative side of the Y axis direction and configured with an XZ plane inclined about the X axis. The first inclined portion 431 and the second inclined portion 432 face each other, and the third inclined portion 433 and the fourth inclined portion 434 face each other through the center O1 in plan view of the lid 4.

[0020] The above-described lid body 4 is a quartz substrate, a silicon substrate, or a glass substrate. This allows the recess 41 with an inclined inner circumferential surface to be easily formed by wet etching. In particular, in this embodiment, like the base substrate 2, it is a silicon substrate. This makes the linear expansion coefficients of the base substrate 2 and the lid body 4 equal, suppressing the occurrence of thermal stress caused by thermal expansion, resulting in a vibration device 1 with excellent vibration characteristics. In addition, since the vibration device 1 can be formed by a semiconductor process, the vibration device 1 can be manufactured with high precision and can be made compact.

[0021] However, the lid 4 is not particularly limited, and a semiconductor substrate other than silicon, such as a semiconductor substrate of Ge, GaP, GaAs, InP, etc., may be used. The lid 4 may also be made of a material other than a semiconductor material, such as quartz crystal or a glass material.

[0022] As shown in FIG. 3, the vibration element 3 has a plate-shaped element substrate 31 having a thickness in the Z-axis direction, and an electrode arranged on the surface of the element substrate 31. The element substrate 31 has a thickness shear vibration mode, and is formed of an AT-cut quartz substrate in this embodiment. The AT-cut quartz substrate has a third-order frequency-temperature characteristic, and therefore the vibration element 3 has excellent temperature characteristics. The electrodes have an excitation electrode 321 arranged on the upper surface of the element substrate 31, and an excitation electrode 322 arranged on the lower surface opposite the excitation electrode 321. The electrodes have a pair of terminals 323 and 324 arranged on the lower surface of the element substrate 31, a wiring 325 that electrically connects the terminal 323 and the excitation electrode 321, and a wiring 326 that electrically connects the terminal 324 and the excitation electrode 322. Note that FIG. 3 shows a center O2 of the vibration element 3 in a plan view. The center O2 is the center of the vibration element 3 in the X-axis direction and the Y-axis direction.

[0023] The vibration element 3 is bonded to the wiring layers 71, 72 by conductive bonding members B1, B2. The bonding member B1 mechanically bonds and electrically connects the wiring layer 71 and the terminal 323. The bonding member B2 mechanically bonds and electrically connects the wiring layer 72 and the terminal 324. In this way, the vibration element 3 is mounted on the base substrate 2, and the vibration element 3 is electrically connected to the oscillation circuit 6.

[0024] The bonding members B1 and B2 are various metal bumps such as gold bumps, silver bumps, copper bumps, and solder bumps. This makes it possible to suppress the generation of gas from the bonding members B1 and B2, and to suppress changes and deterioration in the vibration characteristics of the vibration element 3 due to, for example, contamination of the atmosphere in the accommodation space S caused by gas or pressure changes. This results in a vibration device 1 with excellent reliability. In addition, since the bonding members B1 and B2 do not wet and spread, the bonding members B1 and B2 and the distance between them can be reduced, and the vibration device 1 can be made smaller. However, the bonding members B1 and B2 are not particularly limited, and may be conductive adhesives in which conductive fillers such as silver fillers are dispersed in various adhesives such as polyimide-based, epoxy-based, silicone-based, and acrylic-based adhesives.

[0025] Returning to the description of the vibration element 3, the element substrate 31 is substantially rectangular in plan view. In addition, the element substrate 31 has a first side 331 located on the positive side of the X-axis direction and extending along the Y-axis, a fourth side 334 located on the negative side of the X-axis direction and extending along the Y-axis, a second side 332 located on the positive side of the Y-axis direction and extending along the X-axis, and a third side 333 located on the negative side of the Y-axis direction and extending along the X-axis. The first side 331 and the fourth side 334 face each other in the X-axis direction, and the second side 332 and the third side 333 face each other in the Y-axis direction. In other words, the fourth side 334 is located on the opposite side of the first side 331, and the third side 333 is located on the opposite side of the second side 332.

[0026] The second side 332 is connected at one end (end on the positive side in the X-axis direction) to one end (end on the positive side in the Y-axis direction) of the first side 331, and at the other end (end on the negative side in the X-axis direction) to one end (end on the positive side in the Y-axis direction) of the fourth side 334. The third side 333 is connected at one end (end on the positive side in the X-axis direction) to the other end (end on the negative side in the Y-axis direction) of the first side 331, and at the other end (end on the negative side in the X-axis direction) to the other end (end on the negative side in the Y-axis direction) of the fourth side 334. A first corner 341 is formed between the first side 331 and the second side 332, a second corner 342 is formed between the first side 331 and the third side 333, a third corner 343 is formed between the fourth side 334 and the second side 332, and a fourth corner 344 is formed between the fourth side 334 and the third side 333.

[0027] 4, the first side 331 overlaps with the first inclined portion 431 in plan view. This reduces the gap between the vibration element 3 and the first inclined portion 431, making it possible to miniaturize the vibration device 1. However, this is not limited thereto, and the first side 331 may be located inside the first inclined portion 431.

[0028] Furthermore, the first corner portion 341 and the second corner portion 342 are each cut out in the element substrate 31. By cutting out the first corner portion 341 and the second corner portion 342 in this manner, the following effects can be achieved.

[0029] Prior to describing the effects, an example of a method for manufacturing the vibration device 1 will be described. First, in a base substrate preparation step, a first wafer is prepared in which a large number of base substrates 2 having an oscillator circuit 6 on the lower surface 2b side are formed. Next, in a vibration element mounting step, a vibration element 3 is mounted on each base substrate 2 included in the first wafer using bonding members B1 and B2. Next, in a lid body bonding step, a second wafer is prepared in which a large number of lid bodies 4 having recesses 41 opening on the lower surface are formed, and this second wafer is bonded to the upper surface of the first wafer. This results in a stack of the first and second wafers in which a large number of vibration devices 1 are integrally formed. Finally, in a singulation step, the stack of the first and second wafers is cut to singulate the vibration devices 1. As a result, the vibration device 1 is obtained.

[0030] Here, in the vibration element mounting step, as shown in FIG. 3, it is ideal that the outer edge of the vibration element 3 is mounted along the X-axis direction and the Y-axis direction (hereinafter, also referred to as "ideal state"). However, depending on the accuracy of the vibration element mounting step, as shown in FIG. 5, the vibration element 3 may be mounted tilted around the Z-axis (hereinafter, also referred to as "misaligned state"). When the vibration element 3 is mounted in a misaligned state in this way, the first corner portion 341 or the second corner portion 342 (the second corner portion 342 in the figure) may protrude toward the positive side in the X-axis direction compared to the ideal state and may come into contact with the first inclined portion 431. In particular, in this embodiment, in order to reduce the size of the vibration device 1, the gap between the vibration element 3 and the first inclined portion 431 is made small, so that such contact is likely to occur. If the vibration element 3 comes into contact with the lid body 4, the vibration element 3 may be damaged or may not be able to exhibit the desired vibration characteristics. This increases the number of defective products, and the yield of the vibration device 1 decreases.

[0031] Therefore, by cutting out the first corner portion 341 and the second corner portion 342, the protrusion amount D1 of the first and second corner portions 341, 342 from the ideal state can be reduced compared to when the first and second corner portions 341, 342 are notched. Therefore, the first and second corner portions 341, 342 are less likely to come into contact with the first inclined portion 431. As a result, the rate of defective products is reduced, and the yield of the vibration device 1 is improved.

[0032] In this embodiment, the first corner 341 and the second corner 342 are each cut out in a straight line. This makes it possible to further reduce the protrusion amount D1, and the above-mentioned effect becomes more pronounced. Note that the first corner 341 and the second corner 342 are inclined at about 45° with respect to the X-axis, but the inclination angle is not particularly limited.

[0033] Although the vibration element 3 has been described above, the configuration of the vibration element 3 is not limited to the above configuration. For example, the vibration element 3 may be a mesa type in which the vibration region sandwiched between the excitation electrodes 321 and 322 protrudes from its surroundings, or conversely, may be an inverted mesa type in which the vibration region is recessed from its surroundings.

[0034] Moreover, the vibration element 3 is not limited to one that vibrates in a thickness-shear vibration mode, and may be, for example, a vibration element in which a plurality of vibrating arms vibrate in an in-plane direction. That is, the element substrate 31 is not limited to one formed from an AT-cut quartz substrate, and may be formed from a quartz substrate other than an AT-cut quartz substrate, for example, an X-cut quartz substrate, a Y-cut quartz substrate, a Z-cut quartz substrate, a BT-cut quartz substrate, an SC-cut quartz substrate, an ST-cut quartz substrate, or the like. In addition, in this embodiment, the element substrate 31 is made of quartz, but is not limited thereto, and may be made of a piezoelectric single crystal such as lithium niobate, lithium tantalate, lithium tetraborate, langalite, potassium niobate, or gallium phosphate, or may be made of a piezoelectric single crystal other than these. Furthermore, the vibration element 3 is not limited to a piezoelectric drive type vibration element, and may be an electrostatic drive type vibration element using electrostatic force.

[0035] The above describes the vibration device 1. As described above, the vibration device 1 includes a base substrate 2 having an upper surface 2a as a first surface and a lower surface 2b as a second surface, which are in a front-back relationship, a vibration element 3 mounted on the upper surface 2a side of the base substrate 2, and a lid body 4 having a recess 41 opening to the base substrate 2 side and joined to the upper surface 2a side of the base substrate 2 with the vibration element 3 accommodated in the recess 41. The lid body 4 also has a bottom 4a and a frame-shaped side wall portion 4b standing from the outer edge of the bottom 4a toward the base substrate 2 side. The inner peripheral surface of the side wall portion 4b also has a first inclined portion 431 that is inclined from the bottom 4a side toward the base substrate 2 side so as to move away from a first imaginary center line C1 that passes through a center O1 of the lid body 4 in a plan view and is perpendicular to a surface 42 of the lid body 4 opposite to the recess 41. Further, the vibration element 3 has, in a plan view, a first side 331 facing the first inclined portion 431, a second side 332 along a direction intersecting the first side 331, a first corner portion 341 between the first side 331 and the second side 332, a third side 333 along a direction intersecting the first side 331 and positioned on the opposite side to the second side 332, and a second corner portion 342 between the first side 331 and the third side 333. The first corner portion 341 and the second corner portion 342 are each cut out. As a result, even if the vibration element 3 is mounted on the base substrate 2 in a misaligned state, the protrusion amount D1 is kept small, and contact between the vibration element 3 and the lid body 4 can be effectively suppressed.

[0036] As described above, in plan view, the first inclined portion 431 and the first side 331 overlap each other. This makes the gap between the vibration element 3 and the first inclined portion 431 sufficiently small, and the vibration device 1 can be made smaller in size.

[0037] As described above, the first corner 341 and the second corner 342 are each cut out in a straight line, which makes it possible to further reduce the protrusion amount D1.

[0038] As described above, the lid 4 is a quartz substrate, a silicon substrate, or a glass substrate, and the first inclined portion 431 is a wet-etched surface. This makes it possible to easily form the lid 4 having the first inclined portion 431.

[0039] As described above, the base substrate 2 is a semiconductor substrate on which the oscillator circuit 6 is formed and which is electrically connected to the vibration element 3. This allows the base substrate 2 to be used effectively.

[0040] <Second embodiment> FIG. 6 is a top view showing a vibration element included in the vibration device according to the second embodiment.

[0041] The vibration device 1 according to this embodiment is similar to the vibration device 1 according to the first embodiment described above, except that the configuration of the vibration element 3 is different. In the following description, the vibration device 1 according to this embodiment will be described mainly with respect to the differences from the first embodiment described above, and the description of the similar points will be omitted. In addition, in the drawings of this embodiment, the same reference numerals are used for the same configurations as those in the above-mentioned embodiment.

[0042] 6, in the vibration element 3 of this embodiment, the first corner portion 341 and the second corner portion 342 are each cut out in an arc shape. According to such a configuration, for example, it is possible to reduce stress concentration at the first corner portion 341 and the second corner portion 342 compared to the first embodiment described above.

[0043] The second embodiment as described above can also achieve the same effects as the first embodiment described above.

[0044] <Third embodiment> 7 and 8 are each a top view showing a vibration element included in a vibration device according to the third embodiment.

[0045] The vibration device 1 according to this embodiment is similar to the vibration device 1 according to the first embodiment described above, except that the configuration of the vibration element 3 is different. In the following description, the vibration device 1 according to this embodiment will be described mainly with respect to the differences from the first embodiment described above, and the description of the similar points will be omitted. In addition, in each drawing of this embodiment, the same reference numerals are used for the same configurations as those in the above-mentioned embodiment.

[0046] 7, in the vibration device 1 of this embodiment, the second inclined portion 432 of the lid 4 and the fourth side 334 of the vibration element 3 overlap in a plan view. This reduces the gap between the vibration element 3 and the second inclined portion 432, and the vibration device 1 can be made smaller.

[0047] In addition, the third corner portion 343 and the fourth corner portion 344 of the element substrate 31 are each cut out. That is, all the four corner portions of the element substrate 31 are cut out. In this way, by cutting out the third corner portion 343 and the fourth corner portion 344, the same effect as when the first and second corner portions 341 and 342 are cut out can be achieved. That is, as shown in FIG. 8, when the third corner portion 343 and the fourth corner portion 344 are each cut out, when the vibration element 3 is mounted on the base substrate 2 in a misaligned state, the protrusion amount D2 of the third corner portion 343 or the fourth corner portion 344 from the ideal state can be reduced compared to when the third corner portion 343 or the fourth corner portion 344 is not cut out. Therefore, the third corner portion 343 or the fourth corner portion 344 is less likely to come into contact with the second inclined portion 432. As a result, the rate of defective products is reduced, and the yield of the vibration device 1 is improved.

[0048] In this embodiment, the third corner 343 and the fourth corner 344 are each cut out in a straight line. This makes it possible to further reduce the protrusion amount D2, and the above-mentioned effect becomes more pronounced. Although the third corner 343 and the fourth corner 344 are inclined at about 45° with respect to the X-axis, the inclination angle is not particularly limited.

[0049] As described above, in the vibration device 1 of this embodiment, the inner peripheral surface of the side wall portion 4b has the second inclined portion 432 located on the opposite side of the first imaginary center line C1 to the first inclined portion 431 and inclined so as to move away from the first imaginary center line C1 from the bottom portion 4a side to the base substrate 2 side. In addition, the vibration element 3 has a fourth side 334 located on the opposite side of the first side 331 in a plan view and facing the second inclined portion 432, a third corner portion 343 located between the fourth side 334 and the second side 332, and a fourth corner portion 344 located between the fourth side 334 and the third side 333. The third corner portion 343 and the fourth corner portion 344 are each cut out. As a result, even if the vibration element 3 is mounted on the base substrate 2 in a misaligned state, the protrusion amount D2 of the third corner portion 343 or the fourth corner portion 344 is kept small, and contact between the vibration element 3 and the lid body 4 can be effectively suppressed.

[0050] As described above, in plan view, the second inclined portion 432 overlaps with the fourth side 334. This makes the gap between the vibration element 3 and the second inclined portion 432 sufficiently small, and the vibration device 1 can be made smaller in size.

[0051] As described above, the third corner 343 and the fourth corner 344 are each cut out in a straight line, which makes it possible to further reduce the protrusion amount D2.

[0052] As described above, the lid 4 is a quartz substrate, a silicon substrate, or a glass substrate, and the second inclined portion 432 is a wet-etched surface. This makes it possible to easily form the lid 4 having the second inclined portion 432.

[0053] The third embodiment as described above can also achieve the same effects as the first embodiment described above.

[0054] <Fourth embodiment> FIG. 9 is a top view showing a vibration element included in the vibration device according to the fourth embodiment.

[0055] The vibration device 1 according to this embodiment is similar to the vibration device 1 according to the third embodiment described above, except that the configuration of the vibration element 3 is different. In the following description, the vibration device 1 according to this embodiment will be described with a focus on the differences from the third embodiment described above, and the description of the similar points will be omitted. In addition, in the drawings of this embodiment, the same reference numerals are used for the same configurations as those in the above-mentioned embodiment.

[0056] 9, in the vibration element 3 of this embodiment, the third corner 343 and the fourth corner 344 are each cut out in an arc shape. According to such a configuration, for example, it is possible to reduce stress concentration at the third corner 343 and the fourth corner 344 compared to the third embodiment described above.

[0057] The fourth embodiment as described above can also achieve the same effects as the first embodiment described above.

[0058] <Fifth embodiment> Fig. 10 is a cross-sectional view showing a vibration device according to a fifth embodiment, Fig. 11 and Fig. 12 are cross-sectional views showing modified examples of the vibration device.

[0059] The vibration device 1 according to this embodiment is similar to the vibration device 1 according to the first embodiment described above, except that the configuration of the vibration element 3 is different. In the following description, the vibration device 1 according to this embodiment will be described mainly with respect to the differences from the first embodiment described above, and the description of the similar points will be omitted. In addition, in each drawing of this embodiment, the same reference numerals are used for the same configurations as those in the above-mentioned embodiment.

[0060] 10, the vibration element 3 of this embodiment has an upper surface 351, which is a main surface located on the bottom 4a side, a tip surface 352 located on the tip side and facing the first inclined portion 431, and a tip corner 361 located between the upper surface 351 and the tip surface 352. The tip corner 361 is cut out in a rectangular shape. As a result, the tip of the vibration element 3 has a stepped shape along the first inclined portion 431, so that even if the vibration element 3 is mounted in a misaligned state, contact between the vibration element 3 and the first inclined portion 431 can be effectively suppressed.

[0061] In this embodiment, the tip corner 361 is cut out in a rectangular shape, but the shape of the cutout is not particularly limited. For example, as shown in Figures 11 and 12, the tip corner 361 may be cut out in an arc shape or in a straight line shape. Even with such a shape, the same effect as this embodiment can be achieved.

[0062] As described above, the vibration element 3 of this embodiment has the upper surface 351, which is the main surface located on the bottom 4a side, the tip surface 352 facing the first inclined portion 431, and the tip corner 361 located between the upper surface 351 and the tip surface 352. The tip corner 361 is cut out. This allows the tip of the vibration element 3 to have a shape that conforms to the first inclined portion 431. Therefore, even if the vibration element 3 is mounted in a misaligned state, contact between the vibration element 3 and the first inclined portion 431 can be effectively suppressed.

[0063] The fifth embodiment can also achieve the same effects as the first embodiment described above.

[0064] As with the tip side, the base end corner between the upper surface 351 and the base end surface (the surface located on the base end side facing the second inclined portion 432) may be cut out in a rectangular, linear, or arc shape. This makes the base end of the vibration element 3 step-shaped along the second inclined portion 432, so that even if the vibration element 3 is mounted in a misaligned state, contact between the vibration element 3 and the second inclined portion 432 can be effectively suppressed.

[0065] Sixth embodiment FIG. 13 is a cross-sectional view showing a vibration device according to the sixth embodiment.

[0066] The vibration device 1 according to this embodiment is similar to the vibration device 1 according to the first embodiment described above, except that the configuration of the vibration element 3 is different. In the following description, the vibration device 1 according to this embodiment will be described mainly with respect to the differences from the first embodiment described above, and the description of the similar points will be omitted. In addition, in the drawings of this embodiment, the same reference numerals are used for the same configurations as those in the above-mentioned embodiment.

[0067] 13, the vibration element 3 of this embodiment has a tip surface 352 that is inclined from the bottom 4a side toward the base substrate 2 side so as to move away from a second imaginary center line C2 that passes through a center O2 in a plan view of the vibration element 3 and is perpendicular to the top surface 351 that is the main surface of the vibrator 3. This allows the tip of the vibration element 3 to have a shape that follows the first inclined portion 431, so that even if the vibration element 3 is mounted in a misaligned state, contact between the vibration element 3 and the first inclined portion 431 can be effectively suppressed. Note that in this embodiment, the tip surface 352 is cut out in a straight line, but is not limited thereto, and may be cut out in an arc shape, for example.

[0068] As described above, the vibration element 3 of this embodiment has a tip surface 352 facing the first inclined portion 431. The tip surface 352 is inclined from the bottom 4a side toward the base substrate 2 side so as to move away from the second imaginary center line C2 that passes through the center O2 of the vibration element 3 in a plan view and is perpendicular to the upper surface 351 that is the main surface of the vibrator 3. As a result, the tip portion of the vibration element 3 has a shape that follows the first inclined portion 431, so that even if the vibration element 3 is mounted in a misaligned state, contact between the vibration element 3 and the first inclined portion 431 can be effectively suppressed.

[0069] The sixth embodiment can also achieve the same effects as the first embodiment described above.

[0070] Note that, similarly to the tip surface 352, the base end surface of the vibration element 3 may be inclined so as to move away from the second imaginary center line C2 from the bottom 4a side toward the base substrate 2 side. This makes the base end of the vibration element 3 have a shape that follows the second inclined portion 432, so that even if the vibration element 3 is mounted in a misaligned state, contact between the vibration element 3 and the second inclined portion 432 can be effectively suppressed.

[0071] Seventh embodiment FIG. 14 is a cross-sectional view showing a vibration device according to the seventh embodiment.

[0072] The resonator device 1 according to this embodiment is similar to the resonator device 1 according to the first embodiment described above, except that the arrangement of the oscillator circuit 6 is different. In the following description, the resonator device 1 according to this embodiment will be described with a focus on the differences from the first embodiment described above, and the description of the similarities will be omitted. In addition, in the drawings of this embodiment, the same reference numerals are used for the same configurations as those in the above-described embodiment.

[0073] In the resonator device 1 of this embodiment, the oscillator circuit 6 is formed on the upper surface 2a side of the base substrate 2. By forming the oscillator circuit 6 on the upper surface 2a side of the base substrate 2 in this manner, the oscillator circuit 6 is housed in the package P and protected.

[0074] The terminal layer 65 also has two internal terminals 652, 653 for connecting the oscillation circuit 6 to the vibration element 3. The wiring layer 71 is electrically connected to the electrode pad 621 from the lower surface 2b side of the base substrate 2 through the through hole H1, and the wiring layer 72 is electrically connected to the electrode pad 622 from the lower surface 2b side of the base substrate 2 through the through hole H2. Wiring is drawn from the oscillation circuit 6 to the outside by such wiring layers 71, 72.

[0075] The seventh embodiment as described above can also achieve the same effects as the first embodiment.

[0076] Although the vibration device of the present invention has been described above based on the illustrated embodiment, the present invention is not limited thereto. The configuration of each part can be replaced with any configuration having a similar function. In addition, any other configuration may be added to the present invention. In addition, the present invention may be a combination of any two or more configurations of the above-mentioned embodiments.

[0077] In the above embodiment, the vibration device 1 is applied to an oscillation device, but the application of the vibration device 1 is not particularly limited, and the vibration device 1 can be applied to any device, such as a physical quantity sensor such as an angular velocity sensor or an acceleration sensor. The oscillation circuit 6 may be omitted from the vibration device 1. [Explanation of symbols]

[0078] 1...vibration device, 2...base substrate, 2a...upper surface, 2b...lower surface, 20...insulating layer, 21...through hole, 22...through hole, 3...vibration element, 31...element substrate, 321...excitation electrode, 322...excitation electrode, 323...terminal, 324...terminal, 325...wiring, 326...wiring, 331...first side, 332...second side, 333...third side, 334...fourth side, 341...first corner, 342...second corner, 343...third corner, 344...fourth corner, 351...upper surface, 352...tip surface, 361...tip corner, 4...lid, 4a...bottom, 4b...side wall, 41...recess, 42...surface, 431...first inclined portion, 432...second 2 inclined portion, 433...third inclined portion, 434...fourth inclined portion, 6...oscillating circuit, 60...element, 61...insulating layer, 611...through hole, 612...through hole, 62...wiring layer, 621...electrode pad, 622...electrode pad, 63...insulating layer, 64...passivation film, 65...terminal layer, 651...external terminal, 652...internal terminal, 653...internal terminal, 71...wiring layer, 72...wiring layer, B1...joining member, B2...joining member, C1...first virtual center line, C2...second virtual center line, D1...protrusion amount, D2...protrusion amount, H1...through hole, H2...through hole, O1...center, O2...center, P...package, S...accommodation space

Claims

1. A base substrate having a first surface and a second surface which are in a reverse relationship; A vibration element mounted on the first surface side of the base substrate; a cover body that is joined to the first surface side and has a recess that opens to the base substrate side and accommodates the vibration element in the recess, the lid body has a bottom portion and a frame-shaped side wall portion extending from an outer edge portion of the bottom portion toward the base substrate side, an inner peripheral surface of the side wall portion has a first inclined portion that is inclined from the bottom side toward the base substrate side so as to move away from a first imaginary center line that passes through a center of the lid body in a plan view and is perpendicular to a surface of the lid body opposite to the recessed portion, The vibration element, in a planar view, has a first side opposite the first inclined portion, a second side along a direction intersecting the first side, a first corner between the first side and the second side, a third side along a direction intersecting the first side and positioned opposite the second side, and a second corner between the first side and the third side, wherein the first corner and the second corner are each cut out.

2. The vibration device according to claim 1 , wherein the first inclined portion and the first side overlap in a plan view.

3. The vibration device according to claim 1 , wherein the first corner portion and the second corner portion are each cut out in a linear shape.

4. The vibration device according to claim 1 , wherein the first corner portion and the second corner portion are each cut out in an arc shape.

5. The vibration device of claim 1, wherein the vibration element has a main surface located on the bottom side, a tip surface facing the first inclined portion, and a tip corner portion between the main surface and the tip surface, and the tip corner portion is notched.

6. The vibration element has a tip surface facing the first inclined portion, The vibration device of claim 1 , wherein the tip surface is inclined from the bottom side toward the base substrate side so as to move away from a second imaginary center line that passes through the center of the vibration element in a planar view and is perpendicular to the main surface of the vibration element.

7. the lid is a quartz substrate, a silicon substrate or a glass substrate, The vibration device according to claim 1 , wherein the first inclined portion is a wet-etched surface.

8. the inner circumferential surface of the sidewall portion has a second inclined portion located on the opposite side of the first imaginary center line from the first inclined portion and inclined so as to move away from the first imaginary center line from the bottom side toward the base substrate, The vibration device of claim 1, wherein the vibration element has a fourth side located opposite the first side in a planar view and facing the second inclined portion, a third corner portion between the fourth side and the second side, and a fourth corner portion between the fourth side and the third side, and the third corner portion and the fourth corner portion are each cut out.

9. The vibration device according to claim 8 , wherein the second inclined portion and the fourth side overlap each other in a plan view.

10. The vibration device according to claim 8 , wherein the third corner portion and the fourth corner portion are each linearly cut out.

11. The vibration device according to claim 8 , wherein the third corner portion and the fourth corner portion are each cut out in an arc shape.

12. the lid is a quartz substrate, a silicon substrate or a glass substrate, The vibration device according to claim 8 , wherein the second inclined portion is a wet-etched surface.

13. The vibration device according to claim 1 , wherein the base substrate is a semiconductor substrate on which an oscillation circuit electrically connected to the vibration element is formed.

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