Vibration piece and vibration device

Abstract

To provide a vibration piece and a vibration device that are excellent in G sensitivity characteristics and aging characteristics.SOLUTION: A vibration piece 3 is formed of a SC cut crystal substrate having a surface orthogonal to a Y'' axis. When the length from an outer edge, on a side of an excitation electrode 38, of a first portion 35 of a slit 34 to the other end in a first direction of the SC cut crystal substrate is defined as Lx, and the length in the first direction of a second portion 36 as L1, the relationship of 0.85≤L1 / Lx≤0.97 is satisfied.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a vibrating piece and a vibration device.

Background Art

[0002] For example, Patent Document 1 discloses a vibrating piece including an annular support arm portion, a vibrating portion extending from a part of the inner circumference of the support arm portion, a fixing portion disposed on the other part side facing a part of the support arm portion, and a connecting portion connecting the tip of the vibrating portion and the support arm portion. Further, a vibrating piece is also disclosed in which the gap between the vibrating portion and the support arm portion has an L shape and a gap is disposed between the vibrating portion and the fixing portion. With this configuration, it is difficult for the thermal stress accompanying the temperature change around the fixing portion to be transmitted to the vibrating portion, and an effect of improving the temperature hysteresis characteristic is described.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the vibrating piece described in Patent Document 1 has a problem that although the influence of thermal stress from the fixing portion is reduced, no consideration is given to the G-sensitivity characteristic.

Means for Solving the Problems

[0005] The vibrating piece is composed of an SC-cut crystal substrate having a plane orthogonal to the Y'' axis of an orthogonal coordinate system (X', Y'', Z') obtained by rotating a predetermined angle around the X axis of an orthogonal coordinate system (X, Y, Z) and then rotating a predetermined angle around the Z' axis of the new orthogonal coordinate system (X, Y', Z') obtained by this rotation. It includes a first surface and a second surface that are in a front-back relationship. In plan view, it is provided on one end side in the first direction, and includes a support portion where the first surface side is attached to a container, an excitation portion where excitation electrodes are arranged and that is arranged side by side with the support portion along the first direction in plan view, and a slit. When, in plan view from the second surface side, one end in the first direction faces left and the other end in the first direction faces right, the slit is provided between the support portion and the excitation electrodes, and includes a first portion extending along a second direction intersecting the first direction, and a second portion connected to the upper end of the first portion in the second direction and arranged on the outer edge side of the upper side of the excitation electrodes in the second direction and extending along the first direction. When the length from the outer edge on the excitation electrode side of the first portion of the slit to the other end of the SC-cut crystal substrate in the first direction is Lx and the length of the second portion in the first direction is L1, the relationship 0.85 ≦ L1 / Lx ≦ 0.97 is satisfied.

[0006] The vibrating piece is composed of an SC-cut crystal substrate having a plane orthogonal to the Y'' axis of a rectangular coordinate system (X', Y'', Z') that is rotated by a predetermined angle around the X axis of a rectangular coordinate system (X, Y, Z) and then rotated by a predetermined angle around the Z' axis of the new rectangular coordinate system (X, Y', Z') obtained by this rotation. It includes a first surface and a second surface that are in a front-back relationship. In plan view, it is provided on one end side in a first direction, and includes a support portion where the first surface side is attached to a container, an excitation portion where excitation electrodes are arranged and that is arranged side by side with the support portion along the first direction in plan view, and a slit. When, in plan view from the second surface side, one end in the first direction faces left and the other end in the first direction faces right, the slit is provided between the support portion and the excitation electrodes, and includes a first portion extending along a second direction intersecting the first direction, and a third portion that is connected to the lower end of the first portion in the second direction and is arranged on the outer edge side of the lower side of the excitation electrodes in the second direction and extends along the first direction. When the length from the outer edge on the excitation electrode side of the first portion of the slit to the other end of the SC-cut crystal substrate in the first direction is Lx and the length of the third portion in the first direction is L2, the relationship 0.38 ≦ L2 / Lx ≦ 0.82 is satisfied.

[0007] The vibrating piece is made of an AT-cut crystal substrate having a plane orthogonal to the Y'-axis of a new orthogonal coordinate system (X, Y', Z') obtained by rotating by a predetermined angle around the X-axis of an orthogonal coordinate system (X, Y, Z), includes a first surface and a second surface that are in a front-back relationship, and is provided on one end side in a first direction in a plan view, and a support portion where the first surface side is attached to a container, and in a plan view, is arranged side by side with the support portion along the first direction, and includes an excitation portion where excitation electrodes are arranged, and a slit. When, in a plan view from the second surface side, one end in the first direction faces left and the other end in the first direction faces right, the slit is provided between the support portion and the excitation electrodes, and includes a first portion extending along a second direction intersecting the first direction, and a second portion connected to an upper end of the first portion in the second direction and arranged on an outer edge side of the excitation electrodes in the upper side in the second direction and extending along the first direction. When the length from the outer edge on the excitation electrode side of the first portion of the slit to the other end of the AT-cut crystal substrate in the first direction is Lx, and the length of the second portion in the first direction is L3, the relationship of 0.27 ≦ L3 / Lx ≦ 0.95 is satisfied.

[0008] The vibrating piece is made of an AT-cut crystal substrate having a plane orthogonal to the Y' axis of a new orthogonal coordinate system (X, Y', Z') obtained by rotating by a predetermined angle around the X axis of an orthogonal coordinate system (X, Y, Z). It includes a first surface and a second surface that are in a front-back relationship. In a plan view, it is provided on one end side in a first direction, and includes a support portion where the first surface side is attached to a container, an excitation portion where an excitation electrode is arranged and that is arranged side by side with the support portion along the first direction in a plan view, and a slit. When, in a plan view from the second surface side, one end in the first direction faces left and the other end in the first direction faces right, the slit is provided between the support portion and the excitation electrode, and includes a first portion extending along a second direction intersecting the first direction, and a third portion connected to the lower end of the first portion in the second direction and arranged on the outer edge side of the lower side of the excitation electrode in the second direction and extending along the first direction. When the length from the outer edge on the excitation electrode side of the first portion of the slit to the other end of the AT-cut crystal substrate in the first direction is Lx and the length of the third portion in the first direction is L4, the relationship of 0.27 ≦ L4 / Lx ≦ 0.95 is satisfied.

[0009] The vibration device includes a vibrating piece made of the SC-cut crystal substrate described above, and a container to which the support portion of the vibrating piece is attached.

[0010] The vibration device includes a vibrating piece made of the AT-cut crystal substrate described above, and a container to which the support portion of the vibrating piece is attached.

Brief Description of the Drawings

[0011]

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Embodiments for Carrying Out the Invention

[0012] 1. First Embodiment First, regarding the vibration device 1 according to the first embodiment, taking a vibrator in which the vibrating piece 3 is housed in the container 10 and the lid body 20 as an example, it will be described with reference to FIGS. 1 to 6. In FIG. 1, for the sake of convenience in explaining the internal configuration of the vibration device 1, the state where the lid body 20 is removed is illustrated.

[0013] Also, for the sake of convenience in explanation, in each of the following figures of the vibration devices 1, 1a, 1b, 1c, 1d, 1e, 1f, 1g, the X-axis, Y-axis, and Z-axis are illustrated as three mutually orthogonal axes. Also, the direction along the X-axis is referred to as the "X direction", the direction along the Y-axis is referred to as the "Y direction", and the direction along the Z-axis is referred to as the "Z direction". Also, the tip side of the arrow in each axis direction is also referred to as the "plus side", and the base end side is referred to as the "minus side".

[0014] Furthermore, for the sake of convenience in explanation, in each of the following figures of the vibrating pieces 3, 3a, the X'-axis, Y''-axis, and Z'-axis are illustrated as three mutually orthogonal crystal axes corresponding to the crystal axes of the crystal. Also, the direction along the X'-axis is referred to as the "X' direction", the direction along the Y''-axis is referred to as the "Y'' direction", and the direction along the Z'-axis is referred to as the "Z' direction". Also, the tip side of the arrow in each axis direction is also referred to as the "plus side", and the base end side is referred to as the "minus side". In this embodiment, the first direction is the X' direction, and the second direction is the Z' direction. Also, in each of the following figures of the vibration devices 1, 1a, 1b, 1g, the X-axis coincides with the X'-axis of the crystal axis, the Y-axis coincides with the Z'-axis of the crystal axis, and the Z-axis coincides with the Y''-axis of the crystal axis.

[0015] As shown in FIGS. 1 and 2, the vibration device 1 includes a container 10, a lid body 20, and a vibrating piece 3.

[0016] The container 10 has a third surface 13 and a fourth surface 14 that are in a front-back relationship, and the third surface 13 faces the vibrating piece 3. On the third surface 13, two electrode pads 11 and 12 for joining the vibrating piece 3 are arranged side by side along the Y direction, and on the fourth surface 14, a plurality of external terminals 15 used for power supply and frequency output are provided. Incidentally, the electrode pads 11 and 12 and the external terminals 15 are electrically connected by wiring or through electrodes (not shown). Also, as the constituent material of the container 10, silicon is preferable, and glass, ceramic, or the like may also be used.

[0017] The lid 20 is provided with a recess 21 that opens toward the container 10 side, is joined to the third surface 13 of the container 10 via a joining member 25, and forms an accommodation space 22 that accommodates the vibrating piece 3 together with the container 10. Incidentally, the lid 20 and the container 10 may be directly joined without using the joining member 25. Also, the inside of the accommodation space 22 is in a depressurized state, preferably a state closer to a vacuum. Thereby, the viscous resistance is reduced and the oscillation characteristics of the vibrating piece 3 are improved. Also, as the constituent material of the lid 20, silicon is preferable, and glass, ceramic, or the like may also be used.

[0018] As shown in FIG. 3, the vibrating piece 3 has a crystal substrate 30, excitation electrodes 38, a first connection electrode 41, and a second connection electrode 42. The crystal substrate 30 is an SC-cut crystal substrate. The SC-cut crystal substrate has crystal axes X, Y, and Z that are orthogonal to each other, and the X-axis is called the electrical axis, the Y-axis is called the mechanical axis, and the Z-axis is called the optical axis, respectively. It rotates by a predetermined angle, for example, about 34° counterclockwise around the X-axis of the orthogonal coordinate system (X, Y, Z), and then rotates by a predetermined angle, for example, about 22° counterclockwise around the Z'-axis of the new orthogonal coordinate system (X, Y', Z') obtained by this rotation, and has a plane orthogonal to the Y''-axis of the orthogonal coordinate system (X', Y'', Z').

[0019] In plan view, the crystal substrate 30 is rectangular, with the X' direction as the long side direction, the Z' direction as the short side direction, and the Y'' direction as the thickness direction. The plane including the X' axis and the Z' axis orthogonal to the Y'' axis is the main plane, and thickness-shear vibration is excited as the main vibration on the main plane.

[0020] The crystal substrate 30 has a first surface 31a and a second surface 31b that are in a front-back relationship. In plan view, it is provided on one end side in the X' direction which is the first direction, and includes a support portion 33 provided on the first surface 31a side and attached to the container 10, an excitation portion 32 in which excitation electrodes 38 are arranged and that is arranged side by side with the support portion 33 along the X' direction in plan view, and a slit 34 that penetrates from the first surface 31a to the second surface 31b.

[0021] The first surface 31a of the crystal substrate 30 faces the third surface 13 of the container 10. On the first surface 31a of the crystal substrate 30, an excitation electrode 38, a first connection electrode 41, and a second connection electrode 42 are provided. The excitation electrode 38 is arranged in the excitation portion 32, and the first connection electrode 41 and the second connection electrode 42 are arranged in the support portion 33. The first connection electrode 41 and the second connection electrode 42 are arranged side by side along the short side which is one side of the crystal substrate 30. The first connection electrode 41 faces the electrode pad 11 provided on the container 10, and the second connection electrode 42 faces the electrode pad 12 provided on the container 10. An excitation electrode 38 is provided on the second surface 31b of the crystal substrate 30.

[0022] The excitation electrode 38 provided on the first surface 31a is electrically connected to the first connection electrode 41 via a lead electrode 39. The excitation electrode 38 provided on the second surface 31b is electrically connected to the second connection electrode 42 provided on the first surface 31a via the lead electrode 39 and a side surface electrode 40 provided on the side surface of the crystal substrate 30 on the minus side in the X' direction. Incidentally, the excitation electrode 38 provided on the first surface 31a and the excitation electrode 38 provided on the second surface 31b are arranged so as to overlap in plan view.

[0023] When viewed in plan view from the side of the second surface 31b, when one end in the X' direction faces the left side, that is, the minus side in the X' direction, and the other end in the X' direction faces the right side, that is, the plus side in the X' direction, the slit 34 is provided between the support portion 33 and the excitation electrode 38, and includes a first portion 35 extending along a second direction which is the Z' direction intersecting the X' direction, and a second portion 36 connected to the upper end which is the plus side of the first portion 35 in the Z' direction and disposed on the upper outer edge side which is the plus side of the excitation electrode 38 in the Z' direction and extending along the X' direction. Since the slit 34 is provided between the support portion 33 and the excitation electrode 38, it is possible to suppress the transmission of stress due to distortion and temperature change generated by the joining of the vibrating piece 3 to the container 10 to the excitation portion 32.

[0024] As shown in FIGS. 1 and 2, the support portion 33 of the vibrating piece 3 and the container 10 are joined via conductive joining members 43 and 44. Specifically, the conductive joining member 43 joins and electrically connects the first connection electrode 41 disposed on the support portion 33 and the electrode pad 11. The conductive joining member 44 joins and electrically connects the second connection electrode 42 disposed on the support portion 33 and the electrode pad 12. Further, the constituent materials of the conductive joining members 43 and 44 are metal bumps, solder, conductive adhesives, etc.

[0025] Next, with reference to FIGS. 4 and 5, the relationship between the in-plane rotation angle Ψ of the vibrating piece 3 and the frequency fluctuation amount will be described. Note that the vibrating piece 3 used in the simulation of FIG. 5 is not provided with the slit 34 in order to make the relationship between the in-plane rotation angle Ψ and the frequency fluctuation amount clearer.

[0026] As shown in FIG. 4, the in-plane rotation angle Ψ of the vibrating piece 3 is an angle formed by a virtual line 50 passing through the center of the support portion 33 and the center of the excitation electrode 38 and the X' axis in plan view.

[0027] FIG. 5 shows the result of simulating the amount of frequency variation due to thermal stress with respect to the in-plane rotation angle Ψ of the vibrating piece 3. Note that the amount of frequency variation on the vertical axis is displayed based on the maximum value of the absolute value of the amount of frequency variation. Also, the amount of frequency variation is a numerical value that serves as an index for predicting the aging characteristics. When the amount of frequency variation is positive, the aging characteristics are upward-sloping to the right, and when the amount of frequency variation is negative, the aging characteristics are downward-sloping to the right. From FIG. 5, the in-plane rotation angle Ψ at which the amount of frequency variation is less than ±0.1 is -180° or more and -170° or less, or -20° or more and 5° or less, or 165° or more and 180° or less.

[0028] Next, with the in-plane rotation angle Ψ of the vibrating piece 3 at which the amount of frequency variation is less than ±0.1 set to 0° or 180°, the relationship between the length L1 of the second portion 36 of the slit 34 and the G sensitivity will be described with reference to FIG. 6.

[0029] As shown in FIG. 3, FIG. 6 shows the result of simulating the G sensitivity with respect to L1 / Lx when the length from the outer edge on the excitation electrode 38 side of the first portion 35 of the slit 34 to the other end of the crystal substrate 30 in the X' direction is Lx and the length of the second portion 36 is L1. Note that the G sensitivity is Γ obtained by taking the square root of the sum of the squares of the G sensitivities in the X, Y, and Z directions.

[0030] From FIG. 6, the range of L1 / Lx for which Γ is less than 1 ppb / G, that is, the G sensitivities in the X, Y, and Z directions can each be less than ±1 ppb / G, is 0.85 or more and 0.97 or less, and is a range that satisfies the relationship 0.85 ≤ L1 / Lx ≤ 0.97. By setting the in-plane rotation angle Ψ of the vibrating piece 3 to 0° or 180° and satisfying the relationship 0.85 ≤ L1 / Lx ≤ 0.97, the amount of frequency variation can be made small, and the G sensitivities in the X, Y, and Z directions can each be less than ±1 ppb / G.

[0031] As described above, the vibration device 1 of the present embodiment has an in-plane rotation angle Ψ with a small frequency variation amount of 0° or 180°, and a ratio L1 / Lx of the length L1 of the second portion 36 of the slit 34 to the length Lx of the excitation portion 32 satisfies the relationship of 0.85 ≤ L1 / Lx ≤ 0.97. Therefore, the aging characteristics are excellent, and excellent G-sensitivity characteristics with G-sensitivities in the X, Y, and Z directions of less than ±1 ppb / G can be obtained.

[0032] 2. Second Embodiment Next, the vibration device 1a according to the second embodiment will be described with reference to FIGS. 7, 8, and 9. In FIG. 7, for the sake of convenience in explaining the internal configuration of the vibration device 1a, a state in which the lid body 20 is removed is illustrated.

[0033] The vibration device 1a of the present embodiment is the same as the vibration device 1 of the first embodiment except that the shape of the slit 34a in the vibration piece 3a is different. Hereinafter, the description will focus on the differences from the first embodiment described above, and the description of the same matters will be omitted.

[0034] As shown in FIG. 7, the vibration device 1a includes a container 10, a lid body 20, and a vibration piece 3a.

[0035] As shown in FIG. 8, the vibration piece 3a has a crystal substrate 30a, an excitation electrode 38, a first connection electrode 41, and a second connection electrode 42, and the crystal substrate 30a is an SC-cut crystal substrate.

[0036] The crystal substrate 30 has a first surface 31a and a second surface 31b that are in a front-back relationship, and includes a support portion 33 attached to the container 10 on the first surface 31a side, an excitation portion 32 where the excitation electrode 38 is disposed, and a slit 34a that penetrates from the first surface 31a to the second surface 31b.

[0037] When viewed in plan view from the side of the second surface 31b, when one end in the X' direction faces the left side, that is, the minus side in the X' direction, and the other end in the X' direction faces the right side, that is, the plus side in the X' direction, the slit 34a is provided between the support portion 33 and the excitation electrode 38, and includes a first portion 35 extending along the Z' direction intersecting the X' direction, and a third portion 37 connected to the lower end, which is the minus side of the first portion 35 in the Z' direction, and disposed on the outer edge side of the lower side, which is the minus side of the excitation electrode 38 in the Z' direction, and extending along the X' direction.

[0038] Next, with the in-plane rotation angle Ψ of the vibrating piece 3 such that the frequency fluctuation amount is less than ±0.1 being 0° or 180°, the relationship between the length L2 of the third portion 37 of the slit 34a and the G sensitivity will be described with reference to FIG. 9.

[0039] As shown in FIG. 8, FIG. 9 shows the result of simulating the G sensitivity with respect to L2 / Lx when the length from the outer edge on the excitation electrode 38 side of the first portion 35 of the slit 34a to the other end of the crystal substrate 30 in the X' direction is Lx and the length of the third portion 37 is L2. Note that the G sensitivity is Γ obtained by taking the square root of the sum of the squares of the G sensitivities in the X direction, Y direction, and Z direction.

[0040] From FIG. 9, the range of L2 / Lx for which Γ is less than 1 ppb / G, that is, the G sensitivities in the X direction, Y direction, and Z direction can be made less than ±1 ppb / G respectively, is 0.38 or more and 0.82 or less, and is a range satisfying the relationship 0.38 ≦ L2 / Lx ≦ 0.82. By setting the in-plane rotation angle Ψ of the vibrating piece 3 to 0° or 180° and satisfying the relationship 0.38 ≦ L2 / Lx ≦ 0.82, the frequency fluctuation amount can be small, and the G sensitivities in the X direction, Y direction, and Z direction can be made less than ±1 ppb / G respectively.

[0041] As described above, the vibration device 1a of the present embodiment includes a vibrating piece 3a in which the in-plane rotation angle Ψ with a small frequency fluctuation amount is 0° or 180°, and the ratio L2 / Lx of the length L2 of the third portion 37 of the slit 34 to the length Lx of the excitation portion 32 satisfies the relationship 0.38 ≤ L2 / Lx ≤ 0.82. Therefore, it has excellent aging characteristics and can obtain excellent G-sensitivity characteristics in which the G-sensitivities in the X, Y, and Z directions are each less than ±1.0 ppb / G.

[0042] 3. Third Embodiment Next, the vibration device 1b according to the third embodiment will be described with reference to FIGS. 10 and 11. In FIG. 10, for the sake of convenience in explaining the internal configuration of the vibration device 1b, the state in which the lid body 20 is removed is illustrated.

[0043] The vibration device 1b of the present embodiment is the same as the vibration device 1a of the second embodiment except that the range satisfying L2 / Lx of the vibrating piece 3b is different from that of the vibration device 1a of the second embodiment. Hereinafter, the description will be centered on the differences from the above-described second embodiment, and the description of the same matters will be omitted.

[0044] As shown in FIG. 10, the vibration device 1b includes a container 10, a lid body 20, and a vibrating piece 3b.

[0045] The vibrating piece 3b of the present embodiment has an in-plane rotation angle Ψ with a frequency fluctuation amount of less than ±0.1 being 0° or 180°, and the relationship between the G-sensitivity with respect to the length L2 of the third portion 37 of the slit 34a is the same as that in FIG. 9. Therefore, from FIG. 11, which is the same as FIG. 9, the range of L2 / Lx in which Γ is less than 0.9 ppb / G, that is, the G-sensitivities in the X, Y, and Z directions can be each less than ±0.9 ppb / G, is 0.48 or more and 0.74 or less, and satisfies the relationship 0.48 ≤ L2 / Lx ≤ 0.74.

[0046] As described above, the vibration device 1b of the present embodiment has an in-plane rotation angle Ψ with a small frequency variation amount of 0° or 180°, and a ratio of the length L2 of the third portion 37 of the slit 34 to the length Lx of the excitation portion 32, i.e., L2 / Lx, satisfying the relationship of 0.48 ≤ L2 / Lx ≤ 0.74. Therefore, it has excellent aging characteristics and can obtain excellent G-sensitivity characteristics with G-sensitivities in the X, Y, and Z directions of less than ±0.9 ppb / G, respectively.

[0047] 4. Fourth Embodiment Next, the vibration device 1c according to the fourth embodiment will be described with reference to FIGS. 12 to 16. In FIG. 12, for the sake of convenience in explaining the internal configuration of the vibration device 1c, a state in which the lid body 20 is removed is illustrated.

[0048] Also, for the sake of convenience in explanation, in each of the following figures of the vibration pieces 3c and 3e, three mutually orthogonal crystal axes corresponding to the crystal axes of the crystal are illustrated as the X-axis, Y'-axis, and Z'-axis. Also, the direction along the X-axis is referred to as the "X direction", the direction along the Y'-axis is referred to as the "Y' direction", and the direction along the Z'-axis is referred to as the "Z' direction". Also, the tip side of the arrow in each axis direction is also referred to as the "plus side", and the base end side is referred to as the "minus side". In the present embodiment, the first direction is the X direction, and the second direction is the Z' direction. Also, in each of the following figures of the vibration devices 1c, 1d, 1e, and 1f, the X-axis coincides with the X-axis of the crystal axis, the Y-axis coincides with the Z'-axis of the crystal axis, and the Z-axis coincides with the Y'-axis of the crystal axis.

[0049] The vibration device 1c of the present embodiment is the same as the vibration device 1 of the first embodiment except that the crystal substrate 30c of the vibration piece 3c is different. Hereinafter, the description will focus on the differences from the above-described first embodiment, and the description of the same matters will be omitted.

[0050] As shown in FIG. 12, the vibration device 1c includes a container 10, a lid body 20, and a vibration piece 3c.

[0051] As shown in FIG. 13, the vibration piece 3c has a crystal substrate 30c, an excitation electrode 38, a first connection electrode 41, and a second connection electrode 42. The crystal substrate 30c is an AT-cut crystal substrate. The AT-cut crystal substrate has crystal axes X, Y, and Z that are orthogonal to each other, and the X-axis is called the electrical axis, the Y-axis is called the mechanical axis, and the Z-axis is called the optical axis, respectively. It is rotated by a predetermined angle, for example, about 35°15′ counterclockwise around the X-axis of the orthogonal coordinate system (X, Y, Z), and has a plane orthogonal to the Y'-axis of the new orthogonal coordinate system (X, Y', Z') obtained by this rotation.

[0052] In plan view, the crystal substrate 30c is rectangular, with the X direction as the long side direction, the Z' direction as the short side direction, and the Y' direction as the thickness direction. The plane including the X-axis and the Z'-axis orthogonal to the Y'-axis is the main plane, and the thickness-shear vibration is excited as the main vibration on the main plane.

[0053] The crystal substrate 30c has a first surface 31a and a second surface 31b that are in a front-back relationship, and includes a support portion 33 attached to the container 10 on the first surface 31a side, an excitation portion 32 where an excitation electrode 38 is disposed, and a slit 34 that penetrates from the first surface 31a to the second surface 31b.

[0054] When, in plan view from the second surface 31b side, one end in the X direction faces the left side, that is, the minus side in the X direction, and the other end in the X direction faces the right side, that is, the plus side in the X direction, the slit 34 is provided between the support portion 33 and the excitation electrode 38, and includes a first portion 35 extending along the Z' direction intersecting the X direction, and a second portion 36 that is connected to the upper end, which is the plus side in the Z' direction of the first portion 35, and is disposed on the upper outer edge side, which is the plus side in the Z' direction of the excitation electrode 38, and extends along the X direction.

[0055] Next, the relationship between the in-plane rotation angle Ψ of the vibrating piece 3c and the frequency variation amount will be described with reference to FIGS. 14 and 15. Note that the vibrating piece 3c used in the simulation of FIG. 15 is not provided with a slit 34 in order to make the relationship between the in-plane rotation angle Ψ and the frequency variation amount clearer.

[0056] The in-plane rotation angle Ψ of the vibrating piece 3c is, as shown in Fig. 14, the angle formed by the virtual line 50 passing through the center of the support portion 33 and the center of the excitation electrode 38 and the X-axis in a plan view.

[0057] Fig. 15 shows the result of simulating the frequency variation amount due to thermal stress with respect to the in-plane rotation angle Ψ of the vibrating piece 3c. Note that the frequency variation amount on the vertical axis is displayed based on the maximum value of the absolute value of the frequency variation amount. From Fig. 15, the in-plane rotation angle Ψ for which the frequency variation amount is less than ±0.1 is -110° or more and -70° or less, or 55° or more and 65° or less, or 115° or more and 130° or less.

[0058] Next, in order to simultaneously reduce the G sensitivity and the frequency variation amount, the in-plane rotation angle Ψ for which the frequency variation amount is less than ±0.1 is set to -90°, and the relationship between the length L3 of the second portion 36 of the slit 34 and the G sensitivity will be described with reference to Fig. 16.

[0059] Fig. 16 shows the result of simulating the G sensitivity with respect to L3 / Lx when, as shown in Fig. 13, the length from the outer edge on the excitation electrode 38 side of the first portion 35 of the slit 34 to the other end in the first direction of the crystal substrate 30 is Lx and the length of the second portion 36 is L3. Note that the G sensitivity is Γ obtained by taking the square root of the sum of the squares of the G sensitivities in the X direction, Y direction, and Z direction.

[0060] From Fig. 16, the range of L3 / Lx for which Γ is less than 1 ppb / G, that is, the G sensitivities in the X direction, Y direction, and Z direction can be made less than ±1 ppb / G respectively, is 0.27 or more and 0.95 or less, and is a range that satisfies the relationship 0.27 ≤ L3 / Lx ≤ 0.95. By setting the in-plane rotation angle Ψ of the vibrating piece 3c to -90° and satisfying the relationship 0.27 ≤ L3 / Lx ≤ 0.95, the frequency variation amount can be made small, and the G sensitivities in the X direction, Y direction, and Z direction can be made less than ±1 ppb / G respectively.

[0061] As described above, the vibration device 1c of the present embodiment includes a vibrating piece 3c in which the in-plane rotation angle Ψ with a small frequency fluctuation amount is -90°, and the ratio L3 / Lx of the length L3 of the second portion 36 of the slit 34 to the length Lx of the excitation portion 32 satisfies the relationship of 0.27 ≤ L3 / Lx ≤ 0.95. Therefore, it has excellent aging characteristics and can obtain excellent G-sensitivity characteristics in which the G-sensitivities in the X, Y, and Z directions are each less than ±1 ppb / G.

[0062] 5. Fifth Embodiment Next, the vibration device 1d according to the fifth embodiment will be described with reference to FIGS. 17 and 18. In FIG. 17, for the sake of convenience in explaining the internal configuration of the vibration device 1d, the state in which the lid body 20 is removed is illustrated.

[0063] The vibration device 1d of the present embodiment is the same as the vibration device 1c of the fourth embodiment except that the range satisfying L3 / Lx of the vibrating piece 3d is different from that of the vibration device 1c of the fourth embodiment. Hereinafter, the description will focus on the differences from the fourth embodiment described above, and the description of the same matters will be omitted.

[0064] As shown in FIG. 17, the vibration device 1d includes a container 10, a lid body 20, and a vibrating piece 3d.

[0065] The vibrating piece 3d of the present embodiment has an in-plane rotation angle Ψ with a frequency fluctuation amount of less than ±0.1 being -90°, and the relationship between the length L3 of the second portion 36 of the slit 34 and the G-sensitivity is the same as that in FIG. 16. Therefore, from FIG. 18 which is the same as FIG. 16, the range of L3 / Lx in which Γ is less than 0.9 ppb / G, that is, the G-sensitivities in the X, Y, and Z directions can be each less than ±0.9 ppb / G, is 0.60 or more and 0.88 or less, and is a range satisfying the relationship of 0.60 ≤ L3 / Lx ≤ 0.88.

[0066] As described above, the vibration device 1d of the present embodiment includes a vibrating piece 3d in which the in-plane rotation angle Ψ with a small frequency variation amount is -90°, and the ratio L3 / Lx of the length L3 of the second portion 36 of the slit 34 to the length Lx of the excitation portion 32 satisfies the relationship of 0.60 ≤ L3 / Lx ≤ 0.88. Therefore, it has excellent aging characteristics and can obtain excellent G-sensitivity characteristics in which the G-sensitivities in the X, Y, and Z directions are each less than ±0.9 ppb / G.

[0067] 6. Sixth Embodiment Next, the vibration device 1e according to the sixth embodiment will be described with reference to FIGS. 19, 20, and 21. In FIG. 19, for convenience of explaining the internal configuration of the vibration device 1e, a state in which the lid body 20 is removed is illustrated.

[0068] The vibration device 1e of the present embodiment is the same as the vibration device 1c of the fourth embodiment except that the shape of the slit 34a in the vibrating piece 3e is different from that of the vibrating piece 3c in the fourth embodiment. Hereinafter, the description will focus on the differences from the fourth embodiment described above, and the description of the same matters will be omitted.

[0069] As shown in FIG. 19, the vibration device 1e includes a container 10, a lid body 20, and a vibrating piece 3e.

[0070] As shown in FIG. 20, the vibrating piece 3e has a crystal substrate 30e, an excitation electrode 38, a first connection electrode 41, and a second connection electrode 42, and the crystal substrate 30e is an AT-cut crystal substrate.

[0071] The crystal substrate 30e has a first surface 31a and a second surface 31b that are in a front-back relationship, and includes a support portion 33 attached to the container 10 on the first surface 31a side, an excitation portion 32 where the excitation electrode 38 is disposed, and a slit 34a penetrating from the first surface 31a to the second surface 31b.

[0072] When arranged such that, in a plan view from the side of the second surface 31b, one end in the X direction faces the left side, i.e., the minus side in the X direction, and the other end in the X direction faces the right side, i.e., the plus side in the X direction, the slit 34a includes a first portion 35 provided between the support portion 33 and the excitation electrode 38 and extending along the Z' direction intersecting the X direction, and a third portion 37 connected to the lower end, which is the minus side in the Z' direction of the first portion 35, and arranged on the outer edge side of the lower side, which is the minus side in the Z' direction of the excitation electrode 38, and extending along the X direction.

[0073] Next, with the in-plane rotation angle Ψ at which the frequency fluctuation amount of the vibrating piece 3 becomes less than ±0.1 set to -90°, the relationship between the length L4 of the third portion 37 of the slit 34a and the G sensitivity will be described with reference to FIG. 21.

[0074] As shown in FIG. 20, FIG. 21 shows the result of simulating the G sensitivity with respect to L4 / Lx when the length from the outer edge on the excitation electrode 38 side of the first portion 35 of the slit 34a to the other end in the X direction of the crystal substrate 30 is Lx and the length of the third portion 37 is L4. Note that the G sensitivity is Γ obtained by taking the square root of the sum of the squares of the G sensitivities in the X, Y, and Z directions.

[0075] From FIG. 21, the range of L4 / Lx for which Γ becomes less than 1 ppb / G, that is, the G sensitivities in the X, Y, and Z directions can each be made less than ±1 ppb / G, is 0.27 or more and 0.95 or less, which is a range satisfying the relationship 0.27 ≤ L4 / Lx ≤ 0.95. By setting the in-plane rotation angle Ψ of the vibrating piece 3e to -90° and satisfying the relationship 0.27 ≤ L4 / Lx ≤ 0.95, the frequency fluctuation amount can be made small, and the G sensitivities in the X, Y, and Z directions can each be made less than ±1 ppb / G.

[0076] As described above, the vibration device 1e of the present embodiment includes a vibration piece 3e in which the in-plane rotation angle Ψ with a small frequency variation amount is -90°, and the ratio L4 / Lx of the length L4 of the third portion 37 of the slit 34 to the length Lx of the excitation portion 32 satisfies the relationship of 0.27 ≤ L4 / Lx ≤ 0.95. Therefore, it has excellent aging characteristics and can obtain excellent G-sensitivity characteristics in which the G-sensitivities in the X, Y, and Z directions are each less than ±1.0 ppb / G.

[0077] 7. Seventh Embodiment Next, the vibration device 1f according to the seventh embodiment will be described with reference to FIGS. 22 and 23. In FIG. 22, for the sake of convenience in explaining the internal configuration of the vibration device 1f, the state where the lid body 20 is removed is illustrated.

[0078] The vibration device 1f of the present embodiment is the same as the vibration device 1e of the sixth embodiment except that the range satisfying L4 / Lx of the vibration piece 3f is different. Note that the description will focus on the differences from the sixth embodiment described above, and the description of the same matters will be omitted.

[0079] As shown in FIG. 22, the vibration device 1f includes a container 10, a lid body 20, and a vibration piece 3f.

[0080] The vibration piece 3f of the present embodiment has an in-plane rotation angle Ψ with a frequency variation amount of less than ±0.1 being -90°, and the relationship between the length L4 of the third portion 37 of the slit 34a and the G-sensitivity is the same as that in FIG. 21. Therefore, from FIG. 23, which is the same as FIG. 21, the range of L4 / Lx for which Γ is less than 0.9 ppb / G, that is, the G-sensitivities in the X, Y, and Z directions can each be less than ±0.9 ppb / G, is 0.61 or more and 0.88 or less, and is a range satisfying the relationship of 0.61 ≤ L4 / Lx ≤ 0.88.

[0081] As described above, the vibration device 1f of the present embodiment has an in-plane rotation angle Ψ with a small frequency fluctuation amount of -90°, and a ratio L4 / Lx of the length L4 of the third portion 37 of the slit 34 to the length Lx of the excitation portion 32 satisfies the relationship of 0.61 ≦ L4 / Lx ≦ 0.88. Therefore, it has excellent aging characteristics and can obtain excellent G-sensitivity characteristics with G-sensitivities in the X, Y, and Z directions of less than ±0.9 ppb / G, respectively.

[0082] 8. Eighth Embodiment Next, the vibration device 1g according to the eighth embodiment will be described with reference to FIGS. 24 and 25. In FIG. 24, for the sake of convenience in explaining the internal configuration of the vibration device 1g, a state in which the lid body 20 is removed is illustrated.

[0083] The vibration device 1g of the present embodiment is the same as the vibration device 1 of the first embodiment except that the structure of the container 10g and the structure of the vibration piece 3g are different. Hereinafter, the description will focus on the differences from the first embodiment described above, and the description of the same matters will be omitted.

[0084] As shown in FIGS. 24 and 25, the vibration device 1g includes a container 10g, a lid body 20, and a vibration piece 3g.

[0085] In the container 10g, two electrode pads 11g and 12g are arranged side by side along the X direction, which is the longitudinal direction, on the third surface 13. A plurality of external terminals 15 used for power supply and frequency output are provided on the fourth surface 14.

[0086] The vibration piece 3g has a crystal substrate 30, an excitation electrode 38, a first connection electrode 41g, and a second connection electrode 42g.

[0087] The crystal substrate 30 includes a support portion 33, an excitation portion 32, and a slit 34 provided between the support portion 33 and the excitation electrode 38. The length L1 of the second portion 36 of the slit 34 satisfies the relationship of 0.85 ≦ L1 / Lx ≦ 0.97.

[0088] The crystal substrate 30 has a first surface 31a and a second surface 31b that are in a front-back relationship. A first connection electrode 41g is provided on the first surface 31a of the support portion 33, and a second connection electrode 42g is provided on the second surface 31b of the support portion 33. The first connection electrode 41g and the second connection electrode 42g have a portion that overlaps in the central portion in the short side direction of the crystal substrate 30 in a plan view.

[0089] An excitation electrode 38 is provided on the excitation portion 32 of the crystal substrate 30. The excitation electrode 38 provided on the first surface 31a of the excitation portion 32 is electrically connected to the first connection electrode 41g via a lead electrode 39. The excitation electrode 38 provided on the second surface 31b of the excitation portion 32 is electrically connected to the second connection electrode 42g via a lead electrode 39.

[0090] The first connection electrode 41g is disposed at a position overlapping with an electrode pad 11g provided on the container 10g, and is joined to the electrode pad 11g via a conductive joining member 43g and is electrically connected. The second connection electrode 42g is electrically connected to an electrode pad 12g provided on the container 10g via a bonding wire 45.

[0091] In addition, in the vibrating piece 3g of this embodiment, the crystal substrate 30 which is the SC cut crystal substrate of the first embodiment is used, but it is not limited thereto, and the crystal substrate 30a which is the SC cut crystal substrate used in the second embodiment or the third embodiment may be used. Also, the crystal substrate 30c which is the AT cut crystal substrate used in the fourth embodiment or the fifth embodiment or the crystal substrate 30e which is the AT cut crystal substrate used in the sixth embodiment or the seventh embodiment may be used.

[0092] With such a configuration, the vibrating piece 3g can be supported at one point, the influence of the support stress can be further reduced, and the same effect as that of the first embodiment can be obtained.

Explanation of Reference Numerals

[0093] 1, 1a, 1b, 1c, 1d, 1e, 1f, 1g... vibration device, 3, 3a, 3b, 3c, 3d, 3e, 3f, 3g... vibration piece, 10... container, 11, 12... electrode pads, 13... third surface, 14... fourth surface, 15... external terminal, 20... lid, 21... recess, 22... accommodation space, 25... joining member, 30... crystal substrate, 31a... first surface, 31b... second surface, 32... excitation part, 33... support part, 34... slit, 35... first part, 36... second part, 37... third part, 38... excitation electrode, 39... lead electrode, 40... side electrode, 41... first connection electrode, 42... second connection electrode, 43, 44... conductive joining member, 45... bonding wire, L1, L2, L3, L4, Lx... length, Ψ... in-plane rotation angle.

Claims

1. It consists of an SC-cut crystal substrate having a plane orthogonal to the Y'' axis of an orthogonal coordinate system (X', Y'', Z') obtained by rotating by a predetermined angle around the X axis of an orthogonal coordinate system (X, Y, Z) and then rotating by a predetermined angle around the Z' axis of the new orthogonal coordinate system (X, Y', Z') obtained by this rotation. It includes a first surface and a second surface that are in a front-back relationship. In plan view, a support portion provided on one end side in a first direction, with the first surface side attached to a container. In plan view, an excitation portion arranged side by side with the support portion along the first direction and having excitation electrodes arranged thereon. It includes a slit. When, in a plan view from the second surface side, one end in the first direction faces left and the other end in the first direction faces right. The slit is A first portion provided between the support portion and the excitation electrode and extending along a second direction intersecting the first direction. A second portion connected to the upper end of the first portion in the second direction and arranged on the outer edge side of the upper side of the excitation electrode in the second direction, extending along the first direction. When the length from the outer edge on the excitation electrode side of the first portion of the slit to the other end of the SC-cut crystal substrate in the first direction is Lx and the length of the second portion in the first direction is L1. 0.85 ≤ L1 / Lx ≤ 0.97 Satisfying the relationship of Vibrating piece.

2. It consists of an SC-cut crystal substrate having a plane orthogonal to the Y'' axis of an orthogonal coordinate system (X', Y'', Z') obtained by rotating by a predetermined angle around the X axis of an orthogonal coordinate system (X, Y, Z) and then rotating by a predetermined angle around the Z' axis of the new orthogonal coordinate system (X, Y', Z') obtained by this rotation. It includes a first surface and a second surface that are in a front-back relationship. In plan view, a support portion provided on one end side in a first direction, with the first surface side attached to a container. In plan view, an excitation portion arranged side by side with the support portion along the first direction and having excitation electrodes arranged thereon. It includes a slit. When, in a plan view from the second surface side, one end in the first direction faces left and the other end in the first direction faces right. The slit is A first portion provided between the support portion and the excitation electrode and extending along a second direction intersecting the first direction. connected to the lower end of the first portion in the second direction, disposed on the outer edge side of the lower side of the excitation electrode in the second direction, and including a third portion extending along the first direction; When the length from the outer edge on the excitation electrode side of the first portion of the slit to the other end of the AT-cut crystal substrate in the first direction is Lx, and the length of the third portion in the first direction is L2, 0.38 ≤ L2 / Lx ≤ 0.82 satisfying the relationship of; vibrating piece.

3. In claim 2, 0.48 ≤ L2 / Lx ≤ 0.74 satisfying the relationship of; vibrating piece.

4. Composed of an AT-cut crystal substrate having a plane orthogonal to the Y' axis of a new orthogonal coordinate system (X, Y', Z') obtained by rotating a predetermined angle around the X axis of the orthogonal coordinate system (X, Y, Z), including a first surface and a second surface having a front-back relationship, in a plan view, a support portion provided on one end side in the first direction, with the first surface side attached to a container, in a plan view, an excitation portion arranged side by side with the support portion along the first direction and having an excitation electrode disposed thereon, including a slit, when, in a plan view from the second surface side, one end in the first direction faces left and the other end in the first direction faces right, the slit is a first portion provided between the support portion and the excitation electrode and extending along a second direction intersecting the first direction, connected to the upper end of the first portion in the second direction, disposed on the outer edge side of the upper side of the excitation electrode in the second direction, and including a second portion extending along the first direction, When the length from the outer edge on the excitation electrode side of the first portion of the slit to the other end of the AT-cut crystal substrate in the first direction is Lx, and the length of the second portion in the first direction is L3, 0.27 ≤ L3 / Lx ≤ 0.95 satisfying the relationship of; vibrating piece.

5. Composed of an AT-cut crystal substrate having a plane orthogonal to the Y' axis of a new orthogonal coordinate system (X, Y', Z') obtained by rotating a predetermined angle around the X axis of the orthogonal coordinate system (X, Y, Z), including a first surface and a second surface having a front-back relationship, in a plan view, a support portion provided on one end side in the first direction, with the first surface side attached to a container, in a plan view, an excitation portion arranged side by side with the support portion along the first direction and having an excitation electrode disposed thereon, including a slit, When arranged such that, in a plan view from the second surface side, one end in the first direction faces left and the other end in the first direction faces right, the slit is provided between the support portion and the excitation electrode, and includes a first portion extending along a second direction intersecting the first direction, and a third portion connected to the lower end of the first portion in the second direction and disposed on the outer edge side of the lower side of the excitation electrode in the second direction, the third portion extending along the first direction, when the length from the outer edge on the excitation electrode side of the first portion of the slit to the other end of the AT-cut crystal substrate in the first direction is Lx, and the length of the third portion in the first direction is L4, 0.27 ≤ L4 / Lx ≤ 0.95 satisfies the relationship of a vibrating piece. **Claim 6** In claim 4, 0.60 ≤ L3 / Lx ≤ 0.88 satisfies the relationship of a vibrating piece. **Claim 7** In claim 5, 0.61 ≤ L4 / Lx ≤ 0.88 satisfies the relationship of a vibrating piece. **Claim 8** In any one of claims 1 to 7, the slit penetrates from the first surface to the second surface, a vibrating piece. **Claim 9** In any one of claims 1 to 7, the support portion includes a first connection electrode and a second connection electrode disposed on the first surface of the vibrating piece, and the first connection electrode and the second connection electrode are arranged side by side along one side of the vibrating piece, a vibrating piece. **Claim 10** In any one of claims 1 to 7, the support portion includes a first connection electrode disposed on the first surface of the vibrating piece and a second connection electrode disposed on the second surface of the vibrating piece, and the first connection electrode and the second connection electrode have an overlapping portion in a plan view, a vibrating piece. **Claim 11** a vibrating piece made of an SC-cut crystal substrate according to any one of claims 1 to 3, and a container to which the support portion of the vibrating piece is attached, comprising a vibration device. **Claim 12** a vibrating piece made of an AT-cut crystal substrate according to any one of claims 4 to 7, and a container to which the support portion of the vibrating piece is attached, comprising a vibration device.

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