阅读说明：本技术 振动器件、电子设备以及移动体 (Vibration device, electronic apparatus, and moving object ) 是由 西泽龙太 小仓诚一郎 山口启一 于 2020-03-23 设计创作，主要内容包括：提供振动器件、电子设备以及移动体,能够降低不必要振动。振动器件具有振动结构体,在将彼此垂直的三个轴设为A轴、B轴以及C轴时,该振动结构体具有：振动元件,其具有沿与A轴和B轴平行的平面且沿A轴弯曲振动的第一振动臂和第二振动臂；以及支承基板,其与所述振动元件沿所述C轴排列配置,所述支承基板具有：基部,其支承所述振动元件；支承部,其支承所述基部；以及梁部,其连接所述基部与所述支承部,在设所述振动结构体沿所述B轴振动的共振频率为f0,设所述振动元件的驱动频率为f1时,f0＜f1。(Provided are a vibration device, an electronic apparatus, and a moving object, which can reduce unnecessary vibration. The vibration device has a vibration structure having, as a A axis, a B axis, and a C axis, three axes perpendicular to each other: a vibration element having a first vibration arm and a second vibration arm which flexurally vibrate along a plane parallel to the A-axis and the B-axis and along the A-axis; and a support substrate arranged in line with the vibration element along the C-axis, the support substrate including: a base supporting the vibration element; a support portion that supports the base portion; and a beam portion connecting the base portion and the support portion, wherein f0 < f1 is defined as f0 as a resonance frequency of the vibration structure vibrating along the B axis and f1 as a driving frequency of the vibration element.)

1. A vibration device, characterized in that,

the vibration device has a vibration structure having, as a A axis, a B axis, and a C axis, three axes perpendicular to each other:

a vibrating element having a vibrating arm that flexurally vibrates along a plane parallel to the a-axis and the B-axis and along the a-axis; and

a support substrate arranged in line with the vibration element along the C-axis,

the support substrate includes:

a base supporting the vibration element;

a support portion that supports the base portion; and

a beam portion connecting the base portion and the support portion,

when the resonant frequency of the vibration structure vibrating along the B axis is f0 and the driving frequency of the vibration element is f1,

f0＜f1。

2. the vibration device of claim 1,

when the spring constant of the beam portion elastically deformed along the A axis is Ka and the spring constant of the beam portion elastically deformed along the B axis is Kb,

Ka＞Kb，

when viewed from above in the direction along the C-axis,

the support portion has a first support portion located on one side along the a-axis with respect to the vibration element and a second support portion located on the other side along the a-axis with respect to the vibration element.

3. The vibration device of claim 1,

when viewed from above in the direction along the C-axis,

the support portion has a first support portion located on one side along the B-axis with respect to the vibration element and a second support portion located on the other side along the B-axis.

4. The vibration device according to any one of claims 1 to 3,

the vibration element has:

an element base;

a detection arm extending from the element base toward both sides along the B axis;

a first link arm extending from the element base along the A axis,

a second link arm extending from the element base along the a axis toward an opposite side of a direction in which the first link arm extends; and

the vibrating arm including a first vibrating arm extending from a distal end portion of the first connecting arm toward both sides along the B-axis and a second vibrating arm extending from a distal end portion of the second connecting arm toward both sides along the B-axis,

the element base is fixed to the base via an engaging member.

5. The vibration device of claim 1,

a displacement amplitude magnification of the vibration element along the B-axis at the driving frequency f1 is less than 0.8.

6. The vibration device of claim 1,

the vibration element has a vibration substrate and an electrode disposed on the vibration substrate,

the vibration substrate and the support substrate are formed of quartz substrates having the same cut angle.

7. The vibration device of claim 1,

when viewed from above in the direction along the C-axis,

the support substrate overlaps the vibration arm.

8. The vibration device of claim 1,

the vibration element is a physical quantity sensor element that detects a physical quantity.

9. An electronic device, characterized in that,

the electronic device is provided with:

the vibration device of any one of claims 1 to 8; and

and a signal processing circuit which performs signal processing according to an output signal of the vibration device.

10. A movable body characterized in that a movable body is provided,

the moving body includes:

the vibration device of any one of claims 1 to 8; and

and a signal processing circuit which performs signal processing according to an output signal of the vibration device.

Technical Field

The invention relates to a vibration device, an electronic apparatus, and a moving object.

Background

The vibration element described in patent document 1 includes: a vibrating body; a first support part and a second support part which support the vibrator and are fixed to the package; a pair of beam portions connecting the vibrating body and the first support portion; and a pair of beam portions connecting the vibrating body and the second support portion.

Patent document 1: japanese laid-open patent publication No. 2017-194485

However, in the above-described vibration element, the beam portion must be formed so as to pass through the gap of the vibration body, and therefore the shape of the beam portion is restricted. Therefore, the frequency design of the unnecessary vibration is restricted, and it is difficult to realize a vibration element in which the unnecessary vibration is sufficiently suppressed.

Disclosure of Invention

The vibration device of the present application example includes a vibration structure, and when three axes perpendicular to each other are defined as an a axis, a B axis, and a C axis, the vibration structure includes:

a vibrating element having a vibrating arm that flexurally vibrates along a plane parallel to the a-axis and the B-axis and along the a-axis; and

a support substrate arranged in line with the vibration element along the C-axis,

the support substrate includes:

a base supporting the vibration element;

a support portion that supports the base portion; and

a beam portion connecting the base portion and the support portion,

when the resonant frequency of the vibration structure vibrating along the B axis is f0 and the driving frequency of the vibration element is f1, f0 < f 1.

In the vibration device of the present application example, preferably, when the spring constant of the beam portion elastically deformed along the a axis is Ka and the spring constant of the beam portion elastically deformed along the B axis is Kb,

Ka＞Kb，

when viewed from above in the direction along the C-axis,

the support portion has a first support portion located on one side along the a-axis with respect to the vibration element and a second support portion located on the other side along the a-axis with respect to the vibration element.

In the vibration device of the present application example, it is preferable that, when viewed from above in the direction along the C axis,

the support portion has a first support portion located on one side along the B-axis with respect to the vibration element and a second support portion located on the other side along the B-axis with respect to the vibration element.

In the vibration device of the present application example, it is preferable that the vibration element has:

an element base;

a detection arm extending from the element base toward both sides along the B axis;

a first link arm extending from the element base along the A axis,

a second coupling arm extending from the element base in a direction opposite to a direction in which the a axis extends toward the first coupling arm; and

the vibrating arm including a first vibrating arm extending from a distal end portion of the first connecting arm toward both sides along the B-axis and a second vibrating arm extending from a distal end portion of the second connecting arm toward both sides along the B-axis,

the element base is fixed to the base via an engaging member.

In the vibration device of the present application example, it is preferable that a displacement amplitude magnification of the vibration element along the B axis at the driving frequency f1 is less than 0.8.

In the vibration device of the present application example, it is preferable that the vibration element includes a vibration substrate and an electrode disposed on the vibration substrate,

the vibration substrate and the support substrate are formed of quartz substrates having the same cut angle.

In the vibration device of the present application example, it is preferable that, when viewed from above in the direction along the C axis,

the support substrate overlaps the vibration arm.

In the vibration device of the present application example, it is preferable that the vibration element is a physical quantity sensor element that detects a physical quantity.

An electronic device according to this application example is characterized by comprising:

the above-mentioned vibration device; and

and a signal processing circuit which performs signal processing according to an output signal of the vibration device.

The moving object of the present application example is characterized by comprising:

the above-mentioned vibration device; and

and a signal processing circuit which performs signal processing according to an output signal of the vibration device.

Drawings

Fig. 1 is a sectional view showing a vibration device of a first embodiment.

Fig. 2 is a plan view illustrating the vibration device of fig. 1.

Fig. 3 is a plan view showing a vibration element provided in the vibration device of fig. 1.

Fig. 4 is a schematic diagram illustrating driving of the vibration element of fig. 3.

Fig. 5 is a schematic diagram illustrating driving of the vibration element of fig. 3.

Fig. 6 is a plan view showing a support substrate provided in the vibration device shown in fig. 1.

Fig. 7 is a graph showing the relationship of the frequency ratio f1/fd and the displacement amplitude magnification (gain) of the unnecessary vibration at the drive frequency f 1.

Fig. 8 is a graph showing the relationship between f0/f1 and the displacement amplitude magnification (gain) of the unnecessary vibration at the drive frequency f1 when the frequency ratio f1/fd is 1.

Fig. 9 is a plan view showing a vibration device of the second embodiment.

Fig. 10 is a plan view showing a support substrate provided in the vibration device of the third embodiment.

Fig. 11 is a perspective view showing a personal computer of the fourth embodiment.

Fig. 12 is a perspective view showing a mobile phone of the fifth embodiment.

Fig. 13 is a perspective view showing a digital still camera of the sixth embodiment.

Fig. 14 is a perspective view showing an automobile of the seventh embodiment.

Description of the reference symbols

1: a vibrating device; 10: a vibrating structure; 100: a vibration system; 2: packaging; 21: a base; 211: a recess; 211a, 211b, 211 c: a recess; 22: a cover; 23: an engaging member; 241. 242: an internal terminal; 243: an external terminal; 3: a circuit element; 4: a support substrate; 40: a base; 41: a support portion; 411: a first support section; 412: a second support portion; 42: a beam section; 421: a bending section; 43: a beam section; 431: a bending section; 44: a beam section; 441: a bending section; 45: a beam section; 451: a bending section; 46: a base; 47: a support portion; 471: a first support section; 472: a second support portion; 48: a beam section; 481: a frame portion; 482: a first beam section; 483: a second beam section; 5: wiring; 511. 512: a terminal; 513: leading out a wiring; 521. 522: a terminal; 523: leading out a wiring; 531. 532: a terminal; 533: leading out a wiring; 541. 542: a terminal; 543: leading out a wiring; 551. 552: a terminal; 553: leading out a wiring; 561. 562: a terminal; 563: leading out a wiring; 6: a vibrating element; 7: vibrating the substrate; 70: an element base; 701-706: a terminal; 71: a detection arm; 711: a wide part; 72: a detection arm; 721: a wide part; 73: a first link arm; 74: a second connecting arm; 75: a drive arm; 751: a wide part; 76: a drive arm; 761: a wide part; 77: a drive arm; 771: a wide part; 78: a drive arm; 781: a wide part; 8: an electrode; 81: a drive signal electrode; 82: driving a ground electrode; 83: a first detection signal electrode; 84: a first detection ground electrode; 85: a second detection signal electrode; 86: a second detection ground electrode; 1100: a personal computer; 1102: a keyboard; 1104: a main body portion; 1106: a display unit; 1108: a display unit; 1110: a signal processing circuit; 1200: a mobile phone; 1202: an operation button; 1204: a handset; 1206: a microphone; 1208: a display unit; 1210: a signal processing circuit; 1300: a digital still camera; 1302: a housing; 1304: a light receiving unit; 1306: a shutter button; 1308: a memory; 1310: a display unit; 1312: a signal processing circuit; 1500: an automobile; 1502: a system; 1510: a signal processing circuit; b1, B2: an engaging member; BW: a bonding wire; D. e: an arrow; j1, J2: a central axis; o4: a center; Q1-Q3: a curve; s: an interior space; f 0: a resonant frequency; f 1: a drive frequency; fd: frequency; ω c: the angular velocity.

Detailed Description

Hereinafter, the vibration device, the electronic apparatus, and the moving object according to the present application example will be described in detail with reference to the embodiments shown in the drawings.

< first embodiment >

Fig. 1 is a sectional view showing a vibration device of a first embodiment. Fig. 2 is a plan view illustrating the vibration device of fig. 1. Fig. 3 is a plan view showing a vibration element provided in the vibration device of fig. 1. Fig. 4 and 5 are schematic diagrams illustrating driving of the vibration element of fig. 3. Fig. 6 is a plan view showing a support substrate provided in the vibration device shown in fig. 1. Fig. 7 is a graph showing the relationship of the frequency ratio f1/fd and the displacement amplitude magnification (gain) of the unnecessary vibration at the drive frequency f 1. Fig. 8 is a graph showing the relationship between f0/f1 and the displacement amplitude magnification (gain) of the unnecessary vibration at the drive frequency f1 when the frequency ratio f1/fd is 1. For convenience of explanation, fig. 1 to 6 show three axes perpendicular to each other, i.e., an a axis, a B axis, and a C axis. Hereinafter, the arrow tip side of each axis is also referred to as "positive side", and the opposite side is also referred to as "negative side". Also, the positive side of the C-axis is also referred to as "up", and the negative side is also referred to as "down". In addition, a plan view taken along the C axis is also simply referred to as a "plan view".

The vibration device 1 shown in fig. 1 is a physical quantity sensor for detecting an angular velocity ω C with the C-axis as a detection axis. By using the vibration device 1 as a physical quantity sensor, the vibration device 1 can be mounted on a variety of electronic apparatuses, and the vibration device 1 can be highly convenient. The vibration device 1 includes a package 2, and a circuit element 3, a support substrate 4, and a vibration element 6 housed in the package 2.

The package 2 has: a base 21 having a concave portion 211 opened on an upper surface; and a cover 22 that is joined to the upper surface of the base 21 via a joining member 23 so as to close the opening of the concave portion 211. An internal space S is formed by the concave portion 211 inside the package 2, and the circuit element 3, the support substrate 4, and the vibration element 6 are housed in the internal space S. For example, the base 21 may be made of ceramic such as alumina, and the cover 22 may be made of a metal material such as kovar. However, the material of the base 21 and the cover 22 is not particularly limited.

The internal space S is airtight and in a reduced pressure state (preferably, a state closer to vacuum). Thereby, the vibration characteristics of the vibration element 6 are improved. However, the atmosphere of the internal space S is not particularly limited, and may be, for example, an atmospheric pressure state or a pressurized state.

The concave portion 211 is constituted by a plurality of concave portions, and includes: a concave portion 211a opened on the upper surface of the base 21; a concave portion 211b that is opened at the bottom surface of the concave portion 211a and has a smaller opening width than the concave portion 211 a; and a concave portion 211c that is opened at the bottom surface of the concave portion 211b and has a smaller opening width than the concave portion 211 b. Further, support substrate 4 is fixed to the bottom surface of concave portion 211a in a state of supporting vibration element 6, and circuit element 3 is fixed to the bottom surface of concave portion 211 c.

As shown in fig. 2, in the internal space S, the vibration element 6, the support substrate 4, and the circuit element 3 are arranged to overlap each other in a plan view. In other words, the vibration element 6, the support substrate 4, and the circuit element 3 are arranged in the C-axis direction. This can suppress the planar area of the package 2 from expanding in the directions along the a axis and the B axis, and can realize the miniaturization of the vibration device 1. The support substrate 4 is positioned between the vibration element 6 and the circuit element 3, and supports the vibration element 6 from the lower side, i.e., the C-axis negative side.

As shown in fig. 1 and 2, a plurality of internal terminals 241 are disposed on the bottom surface of concave portion 211a, a plurality of internal terminals 242 are disposed on the bottom surface of concave portion 211b, and a plurality of external terminals 243 are disposed on the bottom surface of base 21. These internal terminals 241, 242 and external terminal 243 are electrically connected via a wiring, not shown, formed in the base 21. The internal terminal 241 is electrically connected to the vibration element 6 via conductive bonding members B1 and B2 and the support substrate 4, and the internal terminal 242 is electrically connected to the circuit element 3 via a bonding wire BW.

The vibration element 6 is an angular velocity sensor element capable of detecting an angular velocity ω C about the C axis as a detection axis, as a physical quantity sensor element. As shown in fig. 3, the vibration element 6 includes a vibration substrate 7 and an electrode 8 disposed on a surface of the vibration substrate 7. The vibration substrate 7 is made of a Z-cut quartz substrate, and includes: an element base 70 located at a central portion of the element; detection arms 71, 72 extending from the element base 70 toward both sides along the B axis; a first link arm 73 extending from the element base 70 along the a axis; a second coupling arm 74 extending from the element base 70 in the direction opposite to the direction in which the a axis extends toward the first coupling arm 73; driving arms 75, 76 as vibrating arms extending from the distal end portion of the first linking arm 73 toward both sides along the B axis; and driving arms 77 and 78 as oscillating arms extending from the distal end portions of the second connecting arms 74 toward both sides along the B axis. The Z-cut quartz substrate has a spread in an X-Y plane defined by an X axis as an electrical axis and a Y axis as a mechanical axis, which are crystal axes of quartz, and has a thickness in a direction along the Z axis as an optical axis.

Each of the detection arms 71 and 72 has a wide portion 711 and 721 at the distal end thereof, which is wider than the proximal end. The drive arms 75, 76, 77, and 78 have wide portions 751, 761, 771, and 781, which are wider than the base end portions, at their respective end portions.

The electrode 8 includes a driving signal electrode 81, a driving ground electrode 82, a first detection signal electrode 83, a first detection ground electrode 84, a second detection signal electrode 85, and a second detection ground electrode 86. The driving signal electrodes 81 are disposed on the upper and lower surfaces of the driving arms 75, 76 and on both side surfaces of the driving arms 77, 78. On the other hand, the driving ground electrodes 82 are disposed on both side surfaces of the driving arms 75, 76 and upper and lower surfaces of the driving arms 77, 78. The first detection signal electrode 83 is disposed on the upper and lower surfaces of the detection arm 71, and the first detection ground electrode 84 is disposed on both side surfaces of the detection arm 71. On the other hand, the second detection signal electrode 85 is disposed on the upper and lower surfaces of the detection arm 72, and the second detection ground electrode 86 is disposed on both side surfaces of the detection arm 72.

The electrodes 81 to 86 are respectively led to the lower surface of the element base 70. Therefore, on the lower surface of the element base 70, there are disposed: a terminal 701 electrically connected to the driving signal electrode 81; a terminal 702 electrically connected to the driving ground electrode 82; a terminal 703 electrically connected to the first detection signal electrode 83; a terminal 704 electrically connected to the first detection ground electrode 84; a terminal 705 electrically connected to the second detection signal electrode 85; and a terminal 706 electrically connected to the second detection ground electrode 86.

Further, as shown in FIG. 3, the vibrating element 6 has electrodes 8 also arranged in the wide portions 751 to 781 of the driving arms 75 to 78. In the vibration device 1, before the lid 22 is joined to the base 21, the electrodes 8 on the wide portions 751 to 781 are irradiated with laser light from the positive C-axis side to remove at least a part of the electrodes 8, whereby the masses of the driving arms 75 to 78 can be reduced, and the vibration balance and the driving frequency of the vibration element 6 can be adjusted. Hereinafter, this step is also referred to as a "driving frequency adjustment step".

Such a vibration element 6 detects the angular velocity ω c as follows. First, when a drive signal is applied between the drive signal electrode 81 and the drive ground electrode 82, as shown in FIG. 4, the drive arms 75 to 78 are flexurally vibrated along the A axis in a plane parallel to the A axis and the B axis. Hereinafter, this driving mode is referred to as a driving vibration mode. Then, when the angular velocity ω c is applied to the vibration element 6 in a state of being driven in the driving vibration mode, the detection vibration mode shown in fig. 5 is newly excited. In the detection vibration mode, coriolis force acts on the drive arms 75 to 78 to excite vibration in the direction indicated by arrow D, and the detection arms 71 and 72 respond to the vibration to perform flexural vibration in the direction indicated by arrow E. The electric charge generated in the detection arm 71 in such a detection vibration mode is taken out as a first detection signal from between the first detection signal electrode 83 and the first detection ground electrode 84, and the electric charge generated in the detection arm 72 is taken out as a second detection signal from between the second detection signal electrode 85 and the second detection ground electrode 86, whereby the angular velocity ω c can be detected from these first detection signal and second detection signal.

As shown in fig. 1, the circuit element 3 is fixed to the bottom surface of the concave portion 211 c. The circuit element 3 includes a drive circuit for driving the vibration element 6 and a detection circuit for detecting the angular velocity ω c applied to the vibration element 6. However, the circuit element 3 is not particularly limited, and may include other circuits such as a temperature compensation circuit, for example.

As shown in fig. 2, the support substrate 4 includes: a base 40; a support portion 41 which supports the base portion 40 and includes a first support portion 411 and a second support portion 412 which are disposed apart on both sides along the axis a of the base portion 40; a pair of beam portions 42, 43 connecting the base portion 40 and the first support portion 411; and a pair of beam portions 44, 45 connecting the base portion 40 and the second support portion 412.

Further, the element base 70 of the vibration element 6 is fixed to the base 40 via a conductive joining member B2, and the first support portion 411 and the second support portion 412 are fixed to the bottom surface of the recess 211a via a joining member B1, respectively. That is, the vibration element 6 is fixed to the base 21 via the support substrate 4. By interposing the support substrate 4 between the vibration element 6 and the base 21 in this manner, the stress transmitted from the base 21 can be absorbed and relaxed by the support substrate 4, and the stress is not easily transmitted to the vibration element 6. Therefore, the decrease or variation in the vibration characteristics of the vibration element 6 can be effectively suppressed.

In particular, in the present embodiment, the first support portion 411 and the second support portion 412 are located outside the vibration element 6 in a plan view. Specifically, the first support portion 411 is located on the a-axis positive side of the vibration element 6, and the second support portion 412 is located on the a-axis negative side of the vibration element 6. Thus, the first support portion 411 and the second support portion 412 can be disposed sufficiently apart from each other with the vibration element 6 interposed therebetween, and therefore the vibration element 6 can be supported by the support substrate 4 in a more stable posture. Therefore, the vibration characteristics of the vibration element 6 are improved.

The bonding members B1 and B2 are not particularly limited as long as they have both conductivity and bondability, and for example, various metal bumps such as gold bumps, silver bumps, copper bumps, and solder bumps, and conductive adhesives in which conductive fillers such as silver fillers are dispersed in various polyimide-based, epoxy-based, silicone-based, and acrylic adhesives can be used. If the former metal bumps are used as the bonding members B1 and B2, the generation of gas from the bonding members B1 and B2 can be suppressed, and the change in the environment of the internal space S, particularly the increase in the pressure, can be effectively suppressed. On the other hand, if the latter conductive adhesive is used as the joining members B1, B2, the joining members B1, B2 are relatively flexible, and the joining members B1, B2 can absorb and relax the above-described stress.

In the present embodiment, a conductive adhesive is used as the bonding member B1, and a metal bump is used as the bonding member B2. By using a conductive adhesive as the joining member B1 for joining the support substrate 4 and the base 21, which are different materials, the joining member B1 can effectively absorb and alleviate the thermal stress caused by the difference in thermal expansion coefficient between them. On the other hand, since the support substrate 4 and the vibration element 6 are bonded by the 6 bonding members B2 arranged in a relatively narrow region, by using the metal bumps as the bonding members B2, wet spreading like a conductive adhesive can be suppressed, and contact between the bonding members B2 can be effectively suppressed.

As shown in fig. 3, the beam portions 42, 43, 44, and 45 have bent portions 421, 431, 441, and 451, respectively, which are bent in an S-shape, and are easily elastically deformed in the a-axis direction and the B-axis direction. Therefore, the beam portions 42 to 45 can more effectively absorb and relax the stress transmitted from the base 21. However, the shape of each of the beam portions 42 to 45 is not particularly limited, and for example, the bent portions 421 to 451 may be omitted and formed linearly. The beam portions 42 to 45 may have at least one shape different from the other shapes.

In addition, in a plan view, the driving arm 75 of the vibration element 6 overlaps the beam portion 42, the driving arm 76 overlaps the beam portion 43, the driving arm 77 overlaps the beam portion 44, and the driving arm 78 overlaps the beam portion 45. Therefore, when the drive arms 75 to 78 are deflected in the C-axis direction by an impact or the like, the drive arms 75 to 78 come into contact with the beam portions 42 to 45, and further excessive deflection is suppressed. That is, the beam portions 42 to 45 function as stoppers for suppressing excessive deformation of the driving arms 75 to 78 in the C-axis direction. This can suppress breakage of the vibration element 6. In particular, since the beam portions 42 to 45 are also soft portions in the support substrate 4, the impact at the time of contact can be alleviated by bringing the driving arms 75 to 78 into contact with the beam portions 42 to 45. In addition, in the present embodiment, the wide portions 751 to 781, which are the distal ends of the drive arms 75 to 78, overlap the beam portions 42 to 45, and therefore excessive deformation of the drive arms 75 to 78 in the C-axis direction can be more effectively suppressed.

However, the present invention is not limited to this, and for example, the base portion 40, the first support portion 411, and the second support portion 412 may overlap the drive arms 75 to 78, or any one of the base portion 40, the first support portion 411, the second support portion 412, and the beam portions 42 to 45 may overlap the drive arms 75 to 78.

Such a support substrate 4 is made of a quartz substrate. By forming the support substrate 4 of a quartz substrate in the same manner as the vibration substrate 7, the thermal expansion coefficients of the support substrate 4 and the vibration substrate 7 can be made equal to each other. Therefore, substantially no thermal stress due to the difference in thermal expansion coefficient between the support substrate 4 and the vibration substrate 7 is generated, and the vibration element 6 is less likely to receive stress. Therefore, the decrease or variation in the vibration characteristics of the vibration element 6 can be more effectively suppressed.

In particular, the support substrate 4 is formed of a quartz substrate having the same chamfer as that of the vibration substrate 7 of the vibration element 6. In the present embodiment, since vibration substrate 7 is formed of a Z-cut quartz substrate, support substrate 4 is also formed of a Z-cut quartz substrate. The crystal axis direction of the support substrate 4 coincides with the crystal axis direction of the vibration substrate 7. That is, in the support substrate 4 and the vibration substrate 7, crystal axes coincide with each other in the X-axis direction, coincide with each other in the Y-axis direction, and coincide with each other in the Z-axis direction. Since the thermal expansion coefficient of quartz differs in the direction along the X axis, the direction along the Y axis, and the direction along the Z axis, the support substrate 4 and the vibration substrate 7 are formed at the same chamfer angle and the crystal axes thereof are aligned with each other, so that the thermal stress described above is less likely to occur between the support substrate 4 and the vibration substrate 7. Therefore, the vibration element 6 is less likely to be subjected to stress, and the deterioration or fluctuation of the vibration characteristics thereof can be more effectively suppressed.

The support substrate 4 is not limited to this, and may have the same chamfer as the vibration substrate 7 but a different crystal axis direction from the vibration substrate 7, for example. The support substrate 4 may be formed of a quartz substrate having a different corner cut from the vibration substrate 7. The support substrate 4 may not be formed of a quartz substrate. In this case, the constituent material of the support substrate 4 is preferably a material having a smaller difference in thermal expansion coefficient from quartz than the constituent material of the base 21.

The support substrate 4 is provided with a wiring 5 for electrically connecting the vibration element 6 and the internal terminal 241. As shown in fig. 6, the wiring 5 includes: terminals 511, 521, 531, 541, 551, 561 arranged on the base 40; terminals 512, 532, 542 disposed on the first support portion 411; and terminals 522, 552, 562, which are disposed on the second support portion 412. The wiring 5 also includes: a lead-out wiring 513 passing through the beam portion 42 and connecting the terminal 511 and the terminal 512; a lead-out wiring 523 passing through the beam 44 and connecting the terminal 521 and the terminal 522; a lead-out wiring 533 which passes through the beam portion 43 and connects the terminal 531 and the terminal 532; a lead-out wiring 543 which passes through the beam portions 42 and 43 and connects the terminal 541 and the terminal 542; a lead-out wiring 553 passing through the beam portion 45 and connecting the terminal 551 and the terminal 552; and a lead-out wiring 563 passing through the beam portions 44, 45 and connecting the terminal 561 and the terminal 562.

Although not shown, the terminals 511 to 561 disposed on the base 40 are electrically connected to the terminals 701 to 706 disposed on the base 70 of the vibration element 6 via the joint members B2, and the terminals 512 to 562 disposed on the first support 411 and the second support 412 are electrically connected to the internal terminal 241 via the joint member B1. Thereby, the vibration element 6 is electrically connected to the circuit element 3.

The structure of the vibration device 1 is briefly described above. Here, in the vibration element 6, for example, if the weight balance of the driving arms 75 to 78 is not sufficiently adjusted by the driving frequency adjustment step of vibrating the substrate 7 and the center of gravity of the vibration element 6 is deviated from the center of the element, unnecessary vibration (hereinafter, simply referred to as "unnecessary vibration") in which the vibration element 6 vibrates along the B axis is generated at the time of driving the vibration mode. If this unnecessary vibration is generated, the vibration leakage of the vibration element 6 becomes large, and accordingly, the Q value is lowered, so that the vibration characteristic of the vibration element 6 is lowered.

Therefore, in the vibration device 1, unnecessary vibration of the vibration element 6 is damped by the support substrate 4 supporting the vibration element 6, and thus a decrease in the vibration characteristics of the vibration element 6 is suppressed. This will be explained in detail below. Hereinafter, the structure including vibrating element 6 and support substrate 4 will also be referred to as "vibrating structure 10". The vibration structure 10 has a vibration system 100, and the vibration system 100 is constituted by a mass portion including a base portion 40 and a vibration element 6, and a spring portion including four beam portions 42 to 45.

As described above, in the vibration device 1, the support substrate 4 supporting the vibration element 6 is formed separately from the vibration element 6, and the support substrate 4 and the vibration element 6 are arranged to overlap along the C axis. This allows the support substrate 4 to be designed freely without being hindered by the vibration element 6. By increasing the degree of freedom in design of the support substrate 4, the design thereof becomes more appropriate, so that unnecessary vibration of the vibration element 6 can be more effectively suppressed.

When the resonant frequency of the vibration system 100, which is the vibration structure 10, vibrating along the B axis is f0 and the driving frequency of the vibration element 6 alone in the driving vibration mode is f1, the vibration device 1 of the present embodiment satisfies the relationship f0 < f 1. The unnecessary vibration of the vibration element 6 is generated by the vibration of the drive arms 75 to 78 in the drive vibration mode, and therefore the frequency is substantially equal to the drive frequency f 1. Therefore, if f0 < f1 is set, a difference occurs between the frequency of the unnecessary vibration substantially as f1 and the resonance frequency f0, in other words, the frequency of the unnecessary vibration is shifted from the resonance frequency f0, and resonance of the vibration system 100 in response to the unnecessary vibration can be suppressed. Therefore, unnecessary vibrations of the vibration element 6 can be effectively damped by the support substrate 4.

Here, f0 > f1 may be set so as to generate a difference between the resonance frequency f0 and the drive frequency f 1. However, in order to make f0 > f1, it is necessary to lighten the mass portion of the vibration system 100 or to increase the spring constant of the spring portion of the vibration system 100. In the former case, for example, the size of the vibration element 6 can be reduced to cope with this, but if the size of the vibration element 6 is reduced, the vibration characteristics of the vibration element 6 are reduced accordingly. On the other hand, in the latter case, the beam portions 42 to 45 can be handled by hardening, but if the beam portions 42 to 45 are hardened, the stress from the package 2 is transmitted to the support substrate 4 accordingly, and is easily transmitted to the vibration element 6. Thus, when f0 > f1, the vibration characteristics of vibration element 6 are degraded due to other factors. In contrast, if f0 < f1 is set as in the present embodiment, such a problem does not occur, and the decrease in the vibration characteristics of the vibration element 6 can be more effectively suppressed.

In particular, in the present embodiment, the beam portions 42 to 45 are formed longer along the a axis than the B axis, and thus the respective beam portions 42 to 45 are more easily elastically deformed along the B axis than along the a axis. That is, in the spring portion of the vibration system 100, Ka > Kb where Ka is the spring constant of elastic deformation along the a axis and Kb is the spring constant of elastic deformation along the B axis. This can effectively lower the resonance frequency f0, and can make the difference f1-f0 between the resonance frequency f0 and the drive frequency f1 larger. Therefore, the effect of attenuating unnecessary vibration of the support substrate 4 is further improved. Further, the spring constants Ka and Kb are preferably 0.2. ltoreq. Kb/Ka. ltoreq.0.8, more preferably 0.3. ltoreq. Kb/Ka. ltoreq.0.7, and further preferably 0.4. ltoreq. Kb/Ka. ltoreq.0.6. This can ensure the mechanical strength of the beam portions 42 to 45 and sufficiently reduce the spring constant Kb. Therefore, the effect of attenuating unnecessary vibration of the support substrate 4 is further improved. However, it is not limited thereto, and Ka.ltoreq.Kb may be used.

Next, fig. 7 shows the relationship between f1/fd and the displacement amplitude magnification (gain) of vibration of the vibration element 6 along the B axis at the drive frequency f1, where fd is the frequency of unnecessary vibration, which is the vibration of the vibration element 6 along the B axis. Further, "displacement amplitude" is the maximum amplitude of the size displacement at the time of vibration, and "displacement amplitude magnification" is the magnification of the displacement amplitude with respect to the displacement amplitude at which f1/fd is 0.01. In the graph, a curve Q1 is the vibration structure 10 of the present embodiment, a curve Q2 is the vibration structure 10 of the second embodiment described later, and a curve Q3 is a vibration element as a comparative example described in japanese patent application laid-open No. 2017-194485, which is cited in the prior art.

As described above, since the frequency fd of the unnecessary vibration is substantially equal to the drive frequency f1, if f1/fd in fig. 7 is compared with 1, it can be seen that the displacement amplitude magnification (gain) of the vibrating structure 10 of the present embodiment is the smallest, and subsequently, the displacement amplitude magnification (gain) of the vibrating structure 10 of the second embodiment described below is the second smallest, and the displacement amplitude magnification (gain) of the vibrating element as a comparative example is the largest. The smaller the displacement amplitude magnification (gain) means the smaller the amplitude of the mass portion in the vibration system 100, that is, the vibration element 6 in the B-axis direction, and therefore, according to the vibration structure 10 of the present embodiment, unnecessary vibration of the vibration element 6 can be more effectively damped.

Fig. 8 shows the relationship between the ratio of the resonance frequency f0 and the drive frequency f1 of the vibration system 100 vibrating along the B axis when f1/fd is 1, that is, the displacement amplitude magnification (gain) of the vibration element 6 vibrating along the B axis at the drive frequency f0/f1 and the drive frequency f 1. From this figure, it is understood that the smaller f0/f1, that is, the larger the difference f1-f0 between the resonance frequency f0 and the drive frequency f1, the smaller the displacement amplitude magnification (gain). In the present embodiment, the displacement amplitude magnification (gain) is less than 0.8. Since the displacement amplitude magnification (gain) of the vibration element exemplified as the comparative example is 0.8, it is possible to exhibit an excellent unnecessary vibration damping effect with respect to the comparative example if it is at least less than 0.8. The displacement amplitude magnification (gain) is preferably less than 0.6, more preferably less than 0.4, and still more preferably less than 0.2. This can more significantly exhibit the effect of damping unnecessary vibrations.

As is clear from fig. 8, f0/f1 may be made smaller than 0.7 so that the displacement amplitude magnification is smaller than 0.8, f0/f1 may be made smaller than 0.65 so that the displacement amplitude magnification is smaller than 0.6, f0/f1 may be made smaller than 0.55 so that the displacement amplitude magnification is smaller than 0.4, and f0/f1 may be made smaller than 0.4 so that the displacement amplitude magnification is smaller than 0.2. That is, f0/f1 is preferably less than 0.7, more preferably less than 0.65, still more preferably less than 0.55, and yet more preferably less than 0.4.

The vibration device 1 is explained above. As described above, the vibration device 1 includes the vibration structure 10, and when three axes perpendicular to each other are defined as the a axis, the B axis, and the C axis, the vibration structure 10 includes: a vibrating element 6 having driving arms 75, 76, 77, 78 as vibrating arms that flexurally vibrate along a plane parallel to the a-axis and the B-axis and along the a-axis; and a support substrate 4 arranged in line with the vibration element 6 along the C axis. The support substrate 4 further includes: a base 40 that supports the vibration element 6; a support portion 41 that supports the base portion 40; and beam portions 42, 43, 44, 45 connecting the base portion 40 and the support portion 41. When the resonant frequency of vibration structure 10 along the B axis is f0 and the driving frequency of vibration element 6 is f1, f0 < f 1. Thus, by making f0 < f1, a difference is substantially generated between the frequency of the unnecessary vibration that is f1 and the resonance frequency f0, and resonance of the vibration system 100 due to the unnecessary vibration can be suppressed. Therefore, unnecessary vibrations of the vibration element 6 can be more effectively damped by the support substrate 4.

As described above, when the spring constant of the beam portions 42, 43, 44, 45 elastically deformed along the a axis is Ka and the spring constant of the beam portions 42, 43, 44, 45 elastically deformed along the B axis is Kb, Ka > Kb. Further, the support portion 41 includes, when viewed from a plane in the C-axis direction: a first support portion 411 located on one side along the a axis with respect to the vibration element 6, and located on the front side in the present embodiment; and a second support portion 412 located on the other side along the a axis with respect to the vibration element 6, and located on the negative side in the present embodiment. By disposing the first support portion 411 and the second support portion 412 on both sides of the vibration element 6 in this manner, the vibration element 6 can be supported in a stable posture. Therefore, the vibration characteristics of the vibration element 6 are stabilized. Further, by arranging the first support portion 411 and the second support portion 412 in line along the a axis, the beam portions 42, 43, 44, and 45 connecting the base portion 40 and the first support portion 411 and the second support portion 412 can be easily formed to be longer along the a axis than the B axis, and the relationship Ka > Kb can be easily satisfied. Therefore, the degree of freedom in designing the support substrate 4 is improved.

Further, as described above, the vibration element 6 includes: an element base 70; detection arms 71, 72 extending from the element base 70 toward both sides along the B axis; a first link arm 73 extending from the element base 70 along the a axis; a second coupling arm 74 extending from the element base 70 in the direction opposite to the direction in which the a axis extends toward the first coupling arm 73; driving arms 75, 76 as vibrating arms extending from the distal end portion of the first linking arm 73 toward both sides along the B axis; and driving arms 77 and 78 as oscillating arms extending from the distal end portions of the second connecting arms 74 toward both sides along the B axis, and the element base 70 is fixed to the base 40 via a joining member B2. Thereby, unnecessary vibration of the vibration element 6 as a physical quantity sensor element for detecting a physical quantity can be more effectively damped, and the vibration device 1 with high accuracy can be realized.

Further, as described above, the displacement amplitude magnification (gain) at which the vibrating element 6 vibrates along the B-axis at the driving frequency f1 is less than 0.8. Thus, unnecessary vibration of the vibration element 6 can be more effectively damped by the support substrate 4.

As described above, the vibration element 6 includes the vibration substrate 7 and the electrode 8 disposed on the vibration substrate 7. The vibration substrate 7 and the support substrate 4 are made of quartz substrates having the same cut angle. This can equalize the thermal expansion coefficients of the support substrate 4 and the vibration substrate 7. Therefore, substantially no thermal stress due to the difference in thermal expansion coefficient between the support substrate 4 and the vibration substrate 7 is generated, and the vibration element 6 is less likely to receive stress. Therefore, the decrease or variation in the vibration characteristics of the vibration element 6 can be more effectively suppressed.

As described above, the support substrate 4 overlaps the drive arms 75, 76, 77, and 78 when viewed from the top in the direction along the C axis. Therefore, the support substrate 4 functions as a stopper that suppresses excessive deformation of the drive arms 75 to 78 in the C-axis direction, and damage to the vibration element 6 can be effectively suppressed.

Further, as described above, the vibration element 6 is a physical quantity sensor element that detects a physical quantity. In particular, in the present embodiment, the vibration element 6 is an angular velocity sensor element that detects the angular velocity ω c. This enables the vibration device 1 to be mounted on a variety of electronic apparatuses, thereby providing the vibration device 1 with high convenience.

In the first embodiment described above, the support substrate 4 is positioned between the vibration element 6 and the circuit element 3 and supports the vibration element 6 from the lower side, i.e., the C-axis negative side, but the vibration element 6 may be positioned between the support substrate 4 and the circuit element 3 and the support substrate 4 may support the vibration element 6 from the upper side, i.e., the C-axis positive side. In the first embodiment, the support substrate 4 is fixed to the bottom surface of the concave portion 211a of the base 21 via the bonding member B1, but the support substrate 4 may be fixed to the circuit element 3 via a bonding member.

< second embodiment >

Fig. 9 is a plan view showing a vibration device of the second embodiment.

The present embodiment is the same as the first embodiment except that the direction of the vibration element 6 is different. In the following description, the present embodiment will be mainly described focusing on differences from the above-described embodiments, and descriptions of the same items will be omitted. In fig. 9, the same components as those of the above embodiment are denoted by the same reference numerals.

As shown in fig. 9, in the support substrate 4 of the present embodiment, the package 2, the support substrate 4, and the circuit element 3, which are portions other than the vibration element 6, are arranged so as to be rotated by 90 ° around the C axis from the arrangement of the first embodiment. That is, the support substrate 4 includes: a base 40; a support portion which supports the base portion 40 and includes a first support portion 411 and a second support portion 412 which are disposed apart on both sides along the B axis of the base portion 40; a pair of beam portions 42, 43 connecting the base portion 40 and the first support portion 411; and a pair of beam portions 44 and 45 connecting the base portion 40 and the second support portion 412. Further, the element base 70 of the vibration element 6 is fixed to the base 40 via a conductive joining member B2, and the first support portion 411 and the second support portion 412 are fixed to the bottom surface of the recess 211a via a joining member B1, respectively. According to such a structure, as shown by a curve Q2 in fig. 7, unnecessary vibration of the vibration element 6 can be effectively damped by the support substrate 4. The support substrate 4 does not rotate about the C axis in the direction of the crystal axis, and the state of the first embodiment is maintained.

As described above, according to the vibration device 1 of the present embodiment, unnecessary vibration of the vibration element 6 can be effectively damped by the support substrate 4, and the vibration element 6 can be supported in a stable posture by disposing the first support portion 411 and the second support portion 412 on both sides of the vibration element 6. Therefore, the vibration characteristics of the vibration element 6 are stabilized.

< third embodiment >

Fig. 10 is a plan view showing a support substrate provided in the vibration device of the third embodiment.

The present embodiment is the same as the first embodiment except that the structure of the support substrate 4 is different. In the following description, the present embodiment will be mainly described with respect to differences from the above-described embodiment, and descriptions of the same items will be omitted. In fig. 10, the same components as those of the above-described embodiment are denoted by the same reference numerals.

As shown in fig. 10, the support substrate 4 of the present embodiment has a ring frame shape. That is, the support substrate 4 includes: a base portion 46 located at the center portion and to which the vibration element 6 is fixed via a joint member B2; a support portion 47 that surrounds the base portion 46, supports the base portion 46, and is fixed to the bottom surface of the concave portion 211a via a joint member B1; and a beam portion 48 located between the base portion 46 and the support portion 47 and connecting the base portion 46 and the support portion 47.

The beam portion 48 includes: a frame 481 having a frame shape, which is located between the base 46 and the support 47 and surrounds the base 46; a first beam portion 482 connecting the base portion 46 and the frame portion 481; and a second beam portion 483 connecting the support portion 47 and the frame portion 481. The first beam portion 482 connects the base portion 46 and the frame portion 481 at the center in the direction of the B-axis, and has its central axis J2 along the a-axis. On the other hand, the second beam portion 483 connects the support portion 47 and the frame portion 481 at the center in the a-axis direction, and has a central axis J1 along the B-axis. That is, the central axes J1 and J2 are perpendicular to each other, and the intersection point thereof substantially coincides with the center O4 of the support substrate 4. However, the central axes J1, J2 may intersect at an angle greater than 0 ° and less than 90 °, and the intersection point thereof may be offset from the center O4.

The support portion 47 has a rectangular frame shape, and the support portion 47 includes a first support portion 471 located on the a-axis positive side with respect to the vibration element 6 and a second support portion 472 located on the a-axis negative side with respect to the vibration element 6 in a plan view. The first supporting portion 471 and the second supporting portion 472 are fixed to the bottom surface of the concave portion 211a via the joint member B1.

With this configuration, the same operational effects as those of the first embodiment can be achieved. In the present embodiment, support portion 47 has a frame shape, but is not limited to this, and may be formed into a C-shape with a part of the circumferential direction broken, for example. The same applies to the frame 481.

< fourth embodiment >

Fig. 11 is a perspective view showing a personal computer of the fourth embodiment.

A personal computer 1100 as an electronic device shown in fig. 11 includes a main body portion 1104 having a keyboard 1102 and a display unit 1106 having a display portion 1108, and the display unit 1106 is supported by a hinge structure portion so as to be rotatable with respect to the main body portion 1104. The personal computer 1100 incorporates the vibration device 1 as a physical quantity sensor and a signal processing circuit 1110 that performs signal processing, that is, controls each unit, based on an output signal from the vibration device 1.

In this way, the personal computer 1100 as an electronic apparatus has the vibration device 1 and the signal processing circuit 1110 that performs signal processing based on an output signal of the vibration device 1. Therefore, the effect of the vibration device 1 can be enjoyed, and high reliability can be exhibited.

< fifth embodiment >

Fig. 12 is a perspective view showing a mobile phone of the fifth embodiment.

A mobile phone 1200 as an electronic device shown in fig. 12 includes an antenna, a plurality of operation buttons 1202, a handset 1204, and a microphone 1206, which are not shown, and a display portion 1208 is disposed between the operation buttons 1202 and the handset 1204. The mobile phone 1200 incorporates the vibration device 1 as a physical quantity sensor and a signal processing circuit 1210 that performs signal processing, i.e., controls each unit, based on an output signal from the vibration device 1.

In this way, the mobile phone 1200 as an electronic apparatus has the vibration device 1 and the signal processing circuit 1210 that performs signal processing based on an output signal of the vibration device 1. Therefore, the effect of the vibration device 1 can be enjoyed, and high reliability can be exhibited.

< sixth embodiment >

Fig. 13 is a perspective view showing a digital still camera of the sixth embodiment.

A digital still camera 1300 as an electronic apparatus shown in fig. 13 includes a housing 1302, and a display portion 1310 is provided on a rear surface of the housing 1302. The display unit 1310 is configured to perform display based on an image pickup signal of the CCD, and functions as a viewfinder for displaying an object as an electronic image. A light receiving unit 1304 including an optical lens, a CCD, and the like is provided on the front side of the case 1302. Then, when the photographer presses the shutter button 1306 while confirming the subject image displayed on the display unit 1310, the image pickup signal of the CCD at that time is transmitted and stored in the memory 1308. The digital still camera 1300 incorporates a vibration device 1 as a physical quantity sensor and a signal processing circuit 1312 that performs signal processing, that is, controls each unit, based on an output signal from the vibration device 1.

In this way, the digital still camera 1300 as an electronic apparatus has the vibration device 1 and the signal processing circuit 1312 that performs signal processing based on an output signal of the vibration device 1. Therefore, the effect of the vibration device 1 can be enjoyed, and high reliability can be exhibited.

The electronic device having the vibration device 1 may be, for example, a smartphone, a tablet terminal, a timepiece including a smart watch, an inkjet ejection device (e.g., an inkjet printer), a wearable terminal such as an HMD (head mounted display), a television, a video camera, a video recorder, a car navigation device, a pager, an electronic organizer, an electronic dictionary, a calculator, an electronic game device, a word processor, a table, a video telephone, a video monitor for theft prevention, an electronic binocular, a POS terminal, an electronic thermometer, a sphygmomanometer, a blood glucose meter, an electrocardiographic measurement device, an ultrasonic diagnostic device, a medical device such as an electronic endoscope, a fish detector, various measuring devices, meters such as a vehicle, an aircraft, and a ship, an instrument, a fish detector, a portable telephone, a, A base station for a mobile terminal, a flight simulator, and the like.

< seventh embodiment >

Fig. 14 is a perspective view showing an automobile of the seventh embodiment.

An automobile 1500 as a mobile body shown in fig. 14 includes a system 1502 such as an engine system, a brake system, and a keyless entry system. The automobile 1500 incorporates the vibration device 1 as a physical quantity sensor and a signal processing circuit 1510 that performs signal processing, i.e., control of the system 1502, based on an output signal from the vibration device 1.

In this way, the automobile 1500 as a moving body has the vibration device 1 and the signal processing circuit 1510 that performs signal processing based on an oscillation signal that is an output signal of the vibration device 1. Therefore, the effect of the vibration device 1 can be enjoyed, and high reliability can be exhibited.

The moving object including the vibration device 1 may be, for example, a robot, an unmanned aircraft, a two-wheeled vehicle, an aircraft, a ship, an electric train, a rocket, a spacecraft, or the like, in addition to the automobile 1500.

The vibration device, the electronic apparatus, and the moving object of the present invention have been described above with reference to the illustrated embodiments, but the present invention is not limited thereto, and the configurations of the respective portions may be replaced with arbitrary configurations having the same functions. In addition, other arbitrary components may be added to the present invention. Further, the respective embodiments may be appropriately combined.