Vibration device, electronic device, and mobile body

Abstract

To provide a vibration device, an electronic apparatus and a moving vehicle with which it is possible to reduce unnecessary vibration.SOLUTION: The vibration device comprises: a base part, when three mutually orthogonal axes are defined as axes A, B and C, including a vibration structure provided with a vibration element having a vibration arm that vibrates by bending along a plane parallel to axes A and B and along the axis A and a support substrate arranged in a row with the vibration element along an axis C, the support substrate supporting the vibration element; a support part for supporting the base part; and a beam part for connecting the base part and the support part. An expression f0<f1 holds true, where f0 denotes the resonance frequency of vibration along the axis B of the vibration structure and f1 denotes the drive frequency of the vibration element.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a vibration device, an electronic device, and a moving body.

Background Art

[0002] The vibration element described in Patent Document 1 includes a vibrating body, a first support portion and a second support portion that support the vibrating body and are fixed to a package or the like, a pair of beam portions that connect the vibrating body and the first support portion, and a pair of beam portions that connect the vibrating body and the second support portion.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the above-described vibration element, since the beam portions have to be formed so as to straddle the gaps of the vibrating body, the shape of the beam portions is restricted. Therefore, the frequency design of unnecessary vibrations is restricted, and it has been difficult to realize a vibration element in which unnecessary vibrations are sufficiently suppressed.

Means for Solving the Problems

[0005] The vibration device according to the present application example, when three axes orthogonal to each other are defined as the A axis, the B axis, and the C axis, a vibration element having a vibrating arm that bends and vibrates along a plane parallel to the A axis and the B axis and along the A axis, and a support substrate arranged side by side along the C axis with the vibration element, and has a vibration structure, the support substrate has a base portion that supports the vibration element, a support portion that supports the base portion, and a beam portion that connects the base portion and the support portion. When the resonance frequency of the vibration along the B axis of the vibration structure is f0 and the driving frequency of the vibration element is f1, f0 < f1.

[0006] In the vibration device according to this application example, when the spring constant of the elastic deformation along the A axis of the beam portion is Ka and the spring constant of the elastic deformation along the B axis of the beam portion is Kb, Ka > Kb, In a plan view from the direction along the C axis, It is preferable that 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.

[0007] In the vibration device according to this application example, in a plan view from the direction along the C axis, It is preferable that 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.

[0008] In the vibration device according to this application example, the vibration element has an element base, detection arms extending from the element base toward both sides along the B axis, a first connecting arm extending from the element base along the A axis, a second connecting arm extending from the element base along the A axis in a direction opposite to the direction in which the first connecting arm extends, vibration arms extending from the tip of the first connecting arm toward both sides along the B axis, vibration arms extending from the tip of the second connecting arm toward both sides along the B axis, along a plane parallel to the A axis and the B axis, and vibrating in a bending manner along the A axis, and has it is preferable that the element base is fixed to the base via a joining member.

[0009] In the vibration device according to this application example, it is preferable that the displacement amplitude magnification of the vibration along the B axis of the vibration element at the drive frequency f1 is less than 0.8.

[0010] In the vibration device according to this application example, the vibration element has a vibration substrate and electrodes disposed on the vibration substrate. It is preferable that the vibration substrate and the support substrate are composed of crystal substrates with the same cut angle.

[0011] In the vibration device according to this application example, in a plan view from the direction along the C axis, it is preferable that the support substrate and the vibration arm overlap.

[0012] In the vibration device according to this application example, it is preferable that the vibration element is a physical quantity sensor element that detects a physical quantity.

[0013] The electronic device according to this application example includes the above-described vibration device and a signal processing circuit that performs signal processing based on an output signal of the vibration device, and is characterized by this.

[0014] The moving body according to this application example includes the above-described vibration device and a signal processing circuit that performs signal processing based on an output signal of the vibration device, and is characterized by this.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

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Figure 10

Figure 11

Figure 12

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Figure 14

Mode for Carrying Out the Invention

[0016] Hereinafter, the vibration device, electronic device, and moving body of this application example will be described in detail based on the embodiments shown in the accompanying drawings.

[0017] <First Embodiment> FIG. 1 is a cross-sectional view showing a vibration device according to the first embodiment. FIG. 2 is a plan view showing the vibration device of FIG. 1. FIG. 3 is a plan view showing a vibration element included in the vibration device of FIG. 1. FIGS. 4 and 5 are schematic views for explaining the driving of the vibration element of FIG. 3. FIG. 6 is a plan view showing a support substrate included in the vibration device shown in FIG. 1. FIG. 7 is a graph showing the relationship between the frequency ratio f1 / fd and the displacement amplitude magnification (gain) of unwanted vibration at the driving frequency f1. FIG. 8 is a graph showing the relationship between f0 / f1 and the displacement amplitude magnification (gain) of unwanted vibration at the driving frequency f1 when the frequency ratio f1 / fd = 1. For convenience of explanation, FIGS. 1 to 6 show the A-axis, B-axis, and C-axis, which are three mutually orthogonal axes. Also, hereinafter, the tip side of the arrow of each axis is also referred to as the "plus side", and the opposite side is also referred to as the "minus side". Also, the plus side of the C-axis is also referred to as "up", and the minus side is also referred to as "down". Also, a plan view from the direction along the C-axis is simply referred to as a "plan view".

[0018] The vibration device 1 shown in FIG. 1 is a physical quantity sensor that detects an angular velocity ωc having 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 wide range of electronic devices, and the vibration device 1 with high convenience is obtained. Such a vibration device 1 has a package 2, a circuit element 3, a support substrate 4, and a vibration element 6 housed in the package 2.

[0019] The package 2 has a base 21 having a recess 211 that opens on the upper surface, and a lid 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 recess 211. An internal space S is formed inside the package 2 by the recess 211, 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 can be made of ceramics such as alumina, and the lid 22 can be made of a metal material such as kovar. However, the constituent materials of the base 21 and the lid 22 are not particularly limited, respectively.

[0020] The storage space S is airtight and is in a depressurized state, preferably a state closer to a vacuum. This improves the vibration characteristics of the vibration element 6. However, the atmosphere of the storage space S is not particularly limited, and for example, it may be in an atmospheric pressure state or a pressurized state.

[0021] Further, the recess 211 is composed of a plurality of recesses, including a recess 211a that opens on the upper surface of the base 21, a recess 211b that opens on the bottom surface of the recess 211a and has a smaller opening width than the recess 211a, and a recess 211c that opens on the bottom surface of the recess 211b and has a smaller opening width than the recess 211b. The support substrate 4 is fixed to the bottom surface of the recess 211a while supporting the vibration element 6, and the circuit element 3 is fixed to the bottom surface of the recess 211c.

[0022] Also, 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 so as to overlap each other in plan view. In other words, the vibration element 6, the support substrate 4, and the circuit element 3 are arranged side by side along the C-axis. This can suppress the expansion of the planar area of the package 2 in the directions along the A-axis and the B-axis, and the vibration device 1 can be miniaturized. Further, the support substrate 4 is located between the vibration element 6 and the circuit element 3 and supports the vibration element 6 from below, that is, from the minus side of the C-axis.

[0023] Also, as shown in FIGS. 1 and 2, a plurality of internal terminals 241 are arranged on the bottom surface of the recess 211a, a plurality of internal terminals 242 are arranged on the bottom surface of the recess 211b, and a plurality of external terminals 243 are arranged on the lower surface of the base 21. These internal terminals 241, 242, and external terminals 243 are electrically connected via 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, B2, and the support substrate 4, and the internal terminal 242 is electrically connected to the circuit element 3 via a bonding wire BW.

[0024] The vibration element 6 is an angular velocity sensor element that can detect the angular velocity ωc with the C-axis as the detection axis as a physical quantity sensor element. As shown in FIG. 3, the vibration element 6 includes a vibration substrate 7 and electrodes 8 disposed on the surface of the vibration substrate 7. The vibration substrate 7 is composed of a Z-cut quartz substrate and includes an element base portion 70 located at the central portion of the element, detection arms 71 and 72 extending from the element base portion 70 along the B-axis to both sides, a first connecting arm 73 extending from the element base portion 70 along the A-axis, a second connecting arm 74 extending from the element base portion 70 along the A-axis in a direction opposite to the direction in which the first connecting arm 73 extends, drive arms 75 and 76 as vibration arms extending from the tip of the first connecting arm 73 along the B-axis to both sides, and drive arms 77 and 78 as vibration arms extending from the tip of the second connecting arm 74 along the B-axis to both sides. The Z-cut quartz substrate has an extent in the X-Y plane defined by the X-axis as the electrical axis and the Y-axis as the mechanical axis, which are crystal axes of quartz, and has a thickness in the direction along the Z-axis as the optical axis.

[0025] Each of the detection arms 71 and 72 has widened portions 711 and 721 at its tip that are wider than the base-side portions. Each of the drive arms 75, 76, 77, and 78 has widened portions 751, 761, 771, and 781 at its tip that are wider than the base-side portions.

[0026] The electrode 8 includes a drive signal electrode 81, a drive 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 drive signal electrode 81 is disposed on the upper and lower surfaces of the drive arms 75 and 76 and on both side surfaces of the drive arms 77 and 78. On the other hand, the drive ground electrode 82 is disposed on both side surfaces of the drive arms 75 and 76 and on the upper and lower surfaces of the drive arms 77 and 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.

[0027] Further, these electrodes 81 to 86 are each routed to the lower surface of the element base 70. Therefore, on the lower surface of the element base 70, there are arranged a terminal 701 electrically connected to the drive signal electrode 81, a terminal 702 electrically connected to the drive 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.

[0028] Also, as shown in FIG. 3, electrodes 8 are also arranged on the wide portions 751 to 781 of the drive arms 75 to 78 of the vibrating element 6. In the vibration device 1, before joining the lid 22 to the base 21, laser light is irradiated from the C-axis plus side onto the electrodes 8 on the wide portions 751 to 781, and at least a part of the electrodes 8 is removed, thereby reducing the mass of the drive arms 75 to 78 and adjusting the vibration balance and drive frequency of the vibrating element 6. Hereinafter, this process is also referred to as the "drive frequency adjustment process".

[0029] Such a vibrating element 6 detects the angular velocity ωc as follows. First, when a drive signal is applied between the drive signal electrode 81 and the drive ground electrode 82, the drive arms 75 to 78 bend and vibrate along the plane parallel to the A-axis and the B-axis and along the A-axis as shown in FIG. 4. Hereinafter, this drive mode is referred to as the drive vibration mode. Then, when an angular velocity ωc is applied to the vibrating element 6 while it is being driven in the drive vibration mode, a detection vibration mode shown in FIG. 5 is newly excited. In the detection vibration mode, a Coriolis force acts on the drive arms 75 to 78, and vibration in the direction shown by the arrow D is excited. In response to this vibration, the detection arms 71 and 72 bend and vibrate in the direction shown by the arrow E. The 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 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, and the angular velocity ωc can be detected based on these first and second detection signals.

[0030] As shown in FIG. 1, the circuit element 3 is fixed to the bottom surface of the recess 211c. The circuit element 3 includes a drive circuit that drives the vibration element 6 and a detection circuit that detects the angular velocity ωc applied to the vibration element 6. However, the circuit element 3 is not particularly limited, and for example, other circuits such as a temperature compensation circuit may be included.

[0031] As shown in FIG. 2, the support substrate 4 includes a base portion 40, a support portion 41 that supports the base portion 40 and is divided and arranged on both sides along the A axis of the base portion 40, the first support portion 411 and the second support portion 412, a pair of beam portions 42 and 43 that connect the base portion 40 and the first support portion 411, and a pair of beam portions 44 and 45 that connect the base portion 40 and the second support portion 412.

[0032] The element base 70 of the vibration element 6 is fixed to the base portion 40 via the conductive bonding 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 the bonding members 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 way, the stress transmitted from the base 21 can be absorbed and relaxed by the support substrate 4, and it becomes difficult for the stress to be transmitted to the vibration element 6. Therefore, a decrease and variation in the vibration characteristics of the vibration element 6 can be effectively suppressed.

[0033] In particular, in the present embodiment, in a plan view, the first and second support portions 411 and 412 are located outside the vibration element 6, respectively. Specifically, the first support portion 411 is located on the plus side of the A axis of the vibration element 6, and the second support portion 412 is located on the minus side of the A axis. Thereby, since the first and second support portions 411 and 412 can be arranged so as to be sufficiently separated from each other with the vibration element 6 interposed therebetween, the vibration element 6 can be supported in a more stable posture by the support substrate 4. Therefore, the vibration characteristics of the vibration element 6 are improved.

[0034] Note that the joining members B1 and B2 are not particularly limited as long as they have both conductivity and joinability. 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 adhesives such as polyimide-based, epoxy-based, silicone-based, and acrylic-based adhesives can be used. When the former metal bumps are used as the joining members B1 and B2, generation of gas from the joining members B1 and B2 can be suppressed, and environmental changes in the internal space S, particularly an increase in pressure, can be effectively suppressed. On the other hand, when the latter conductive adhesive is used as the joining members B1 and B2, the joining members B1 and B2 become relatively soft, and the above-described stress can also be absorbed and relaxed in the joining members B1 and B2.

[0035] In the present embodiment, a conductive adhesive is used as the joining member B1, and a metal bump is used as the joining 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 thermal stress caused by the difference in the coefficient of thermal expansion between them can be effectively absorbed and relaxed by the joining member B1. On the other hand, since the support substrate 4 and the vibration element 6 are joined by six joining members B2 arranged in a relatively narrow region, by using metal bumps as the joining members B2, wetting spread such as that of a conductive adhesive is suppressed, and contact between the joining members B2 can be effectively suppressed.

[0036] As shown in FIG. 3, the beam portions 42, 43, 44, and 45 each have bent portions 421, 431, 441, and 451 that meander in an S shape in the middle thereof, and have a shape that is 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 shapes of the beam portions 42 to 45 are not particularly limited, and for example, the bent portions 421 to 451 may be omitted to form a straight shape. Also, at least one of the beam portions 42 to 45 may have a shape different from the others.

[0037] Also, in a plan view, the driving arms 75 of the vibration element 6 overlap with the beam portion 42, the driving arm 76 overlaps with the beam portion 43, the driving arm 77 overlaps with the beam portion 44, and the driving arm 78 overlaps with the beam portion 45. Therefore, when the driving arms 75 to 78 are bent in the C-axis direction due to an impact or the like, the driving arms 75 to 78 come into contact with the beam portions 42 to 45, and excessive bending beyond that is suppressed. That is, the beam portions 42 to 45 function as stoppers that suppress excessive deformation of the driving arms 75 to 78 in the C-axis direction. Thereby, breakage of the vibration element 6 can be suppressed. In particular, since the beam portions 42 to 45 are soft portions among the support substrate 4, the impact at the time of contact can also be reduced by bringing the driving arms 75 to 78 into contact with the beam portions 42 to 45. Further, in the present embodiment, since the tip portions of the driving arms 75 to 78, that is, the wide portions 751 to 781, overlap with the beam portions 42 to 45, excessive deformation of the driving arms 75 to 78 in the C-axis direction can be more effectively suppressed.

[0038] However, it is not limited to this. For example, the base portion 40 and the first and second support portions 411 and 412 may overlap with the driving arms 75 to 78, or none of the base portion 40, the first and second support portions 411 and 412, and the beam portions 42 to 45 may overlap with the driving arms 75 to 78.

[0039] Such a support substrate 4 is composed of a crystal substrate. Thus, by configuring the support substrate 4 with a crystal 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. Therefore, substantially no thermal stress caused by the difference in thermal expansion coefficients between the support substrate 4 and the vibration substrate 7 occurs, and the vibration element 6 becomes less susceptible to stress. Therefore, a decrease and variation in the vibration characteristics of the vibration element 6 can be more effectively suppressed.

[0040] In particular, the support substrate 4 is composed of a quartz substrate having the same cut angle as the vibration substrate 7 of the vibration element 6. In the present embodiment, since the vibration substrate 7 is composed of a Z-cut quartz substrate, the support substrate 4 is also composed of a Z-cut quartz substrate. Further, the direction of the crystal axis of the support substrate 4 is the same as the direction of the crystal axis of the vibration substrate 7. That is, the directions along the X-axis, the Y-axis, and the Z-axis of the support substrate 4 and the vibration substrate 7 coincide with each other. Since quartz has different coefficients of thermal expansion in the directions along the X-axis, the Y-axis, and the Z-axis, by making the support substrate 4 and the vibration substrate 7 have the same cut angle and aligning the directions of their crystal axes with each other, it becomes more difficult for the above-described thermal stress to occur between the support substrate 4 and the vibration substrate 7. Therefore, it becomes more difficult for the vibration element 6 to receive stress, and the decrease and variation of its vibration characteristics can be more effectively suppressed.

[0041] Note that the support substrate 4 is not limited to this. For example, although it has the same cut angle as the vibration substrate 7, the direction of the crystal axis may be different from that of the vibration substrate 7. Further, the support substrate 4 may be formed from a quartz substrate having a cut angle different from that of the vibration substrate 7. Further, the support substrate 4 may not be formed from a quartz substrate. In this case, the constituent material of the support substrate 4 is preferably a material whose difference in coefficient of thermal expansion from quartz is smaller than the difference in coefficient of thermal expansion between quartz and the constituent material of the base 21.

[0042] In addition, on the support substrate 4, a wiring 5 for electrically connecting the vibration element 6 and the internal terminal 241 is arranged. As shown in FIG. 6, the wiring 5 includes terminals 511, 521, 531, 541, 551, 561 arranged on the base portion 40, terminals 512, 532, 542 arranged on the first support portion 411, and terminals 522, 552, 562 arranged on the second support portion 412. Further, the wiring 5 includes a lead-out wiring 513 that connects the terminal 511 and the terminal 512 through the beam portion 42, a lead-out wiring 523 that connects the terminal 521 and the terminal 522 through the beam portion 44, a lead-out wiring 533 that connects the terminal 531 and the terminal 532 through the beam portion 43, a lead-out wiring 543 that connects the terminal 541 and the terminal 542 through the beam portions 42 and 43, a lead-out wiring 553 that connects the terminal 551 and the terminal 552 through the beam portion 45, and a lead-out wiring 563 that connects the terminal 561 and the terminal 562 through the beam portions 44 and 45.

[0043] Although not shown, the terminals 511 to 561 arranged on the base portion 40 are electrically connected to the terminals 701 to 706 arranged on the element base portion 70 of the vibration element 6 via the joining member B2, and the terminals 512 to 562 arranged on the first and second support portions 411 and 412 are electrically connected to the internal terminal 241 via the joining member B1. Thereby, the vibration element 6 and the circuit element 3 are electrically connected.

[0044] The configuration of the vibration device 1 has been briefly described above. Here, in the above-described vibration element 6, for example, if the weight balance of the drive arms 75 to 78 is not sufficiently adjusted by the drive frequency adjustment process of the vibration substrate 7 and the center of gravity of the vibration element 6 is displaced 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 occurs during the drive vibration mode. When this unnecessary vibration occurs, the vibration leakage of the vibration element 6 increases, and accordingly, the Q value decreases and the vibration characteristics of the vibration element 6 deteriorate.

[0045] Therefore, in the vibration device 1, the support substrate 4 that supports the vibration element 6 is configured to attenuate unnecessary vibrations of the vibration element 6 and suppress a decrease in the vibration characteristics of the vibration element 6. This will be described in detail below. Note that hereinafter, the structure composed of the vibration element 6 and the support substrate 4 is also referred to as the "vibration structure 10". The vibration structure 10 has a vibration system 100 composed of a mass portion including a base portion 40 and the vibration element 6, and a spring portion including four beam portions 42 to 45.

[0046] As described above, in the vibration device 1, the support substrate 4 that supports the vibration element 6 is configured separately from the vibration element 6, and moreover, the support substrate 4 and the vibration element 6 are arranged overlapping each other along the C axis. Thereby, the support substrate 4 can be freely designed without being obstructed by the vibration element 6. By increasing the design freedom of the support substrate 4, its design becomes more suitable, and unnecessary vibrations of the vibration element 6 can be suppressed more effectively.

[0047] When the resonance frequency of the vibration along the B axis of the vibration structure 10, that is, the vibration system 100 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 < f1. Since the unnecessary vibrations of the vibration element 6 are caused by the vibrations of the driving arms 75 to 78 in the driving vibration mode, the frequency thereof is substantially equal to the driving frequency f1. Therefore, by setting f0 < f1, a difference is generated between the frequency of the unnecessary vibrations, which is substantially f1, and the resonance frequency f0. In other words, the frequency of the unnecessary vibrations is deviated from the resonance frequency f0, and the resonance of the vibration system 100 corresponding to the unnecessary vibrations can be suppressed. Therefore, the unnecessary vibrations of the vibration element 6 can be effectively attenuated by the support substrate 4.

[0048] Here, in order to create a difference between the resonance frequency f0 and the driving frequency f1, f0 > f1 may be satisfied. However, in order to make f0 > f1, it is necessary to reduce the mass portion of the vibration system 100 or increase the spring constant of the spring portion of the vibration system 100. In the former case, for example, it can be achieved by reducing the size of the vibration element 6. However, if the size of the vibration element 6 is reduced, the vibration characteristics of the vibration element 6 will deteriorate accordingly. On the other hand, in the latter case, it can be achieved by making the beam portions 42 to 45 stiffer. However, if the beam portions 42 to 45 are made stiffer, the stress from the package 2 will be more likely to be transmitted to the vibration element 6 through the support substrate 4. Thus, when f0 > f1, the vibration characteristics of the vibration element 6 will deteriorate due to other factors. In contrast, if f0 < f1 as in the present embodiment, such problems will not occur, and the deterioration of the vibration characteristics of the vibration element 6 can be suppressed more effectively.

[0049] In particular, in the present embodiment, the beam portions 42 to 45 are formed to be longer along the A axis than along the B axis. As a result, each of the beam portions 42 to 45 is more likely to elastically deform along the B axis than along the elastic deformation along the A axis. That is, in the spring portion of the vibration system 100, when the spring constant of the elastic deformation along the A axis is Ka and the spring constant of the elastic deformation along the B axis is Kb, Ka > Kb. Thereby, the resonance frequency f0 can be effectively reduced, and the difference f1 - f0 between the resonance frequency f0 and the driving frequency f1 can be made larger. Therefore, the attenuation effect of unnecessary vibration by the support substrate 4 is further improved. Note that it is preferable that the spring constants Ka and Kb satisfy 0.2 ≦ Kb / Ka ≦ 0.8, more preferably 0.3 ≦ Kb / Ka ≦ 0.7, and even more preferably 0.4 ≦ Kb / Ka ≦ 0.6. Thereby, while ensuring the mechanical strength of the beam portions 42 to 45, the spring constant Kb can be made sufficiently small. Therefore, the attenuation effect of unnecessary vibration by the support substrate 4 is further improved. However, it is not limited thereto, and Ka ≦ Kb may be satisfied.

[0050] Next, FIG. 7 shows the relationship between f1 / fd when fd is the frequency of unnecessary vibration, which is the vibration along the B-axis of the vibration element 6, and the displacement amplitude magnification (gain) of the vibration along the B-axis of the vibration element 6 at the driving frequency f1. Note that the "displacement amplitude" is the maximum width of the dimensional displacement during vibration, and the "displacement amplitude magnification" is the magnification of the displacement amplitude with respect to the displacement amplitude when f1 / fd is 0.01. Curve Q1 in this graph is the vibration structure 10 of the present embodiment, curve Q2 is the vibration structure 10 of the second embodiment described later, and curve Q3 is the vibration element as a comparative example described in Japanese Patent Application Laid-Open No. 2017-194485 cited in the prior art.

[0051] As described above, since the frequency fd of the unnecessary vibration is substantially equal to the driving frequency f1, by comparing at f1 / fd = 1 in FIG. 7, it can be seen that the displacement amplitude magnification (gain) of the vibration structure 10 of the present embodiment is the smallest, followed by the displacement amplitude magnification (gain) of the vibration structure 10 of the second embodiment described later, and the displacement amplitude magnification (gain) of the vibration element as a comparative example is the largest. The smaller the displacement amplitude magnification (gain), the smaller the amplitude of the mass part in the vibration system 10, that is, the amplitude in the B-axis direction of the vibration element 6. Therefore, according to the vibration structure 10 of the present embodiment, the unnecessary vibration of the vibration element 6 can be more effectively attenuated.

[0052] Further, Fig. 8 shows the relationship between f0 / f1, which is the ratio of the resonance frequency f0 of the vibration along the B-axis of the vibration system 100 to the driving frequency f1 when f1 / fd = 1, and the displacement amplitude magnification (gain) of the vibration along the B-axis of the vibration element 6 at the driving frequency f1. As can be seen from this figure, the smaller f0 / f1 is, that is, the larger the difference between the resonance frequency f0 and the driving frequency f1: f1 - f0 is, the smaller the displacement amplitude magnification (gain) becomes. And in this embodiment, the displacement amplitude magnification (gain) is less than 0.8. Since the displacement amplitude magnification (gain) of the vibration element cited as a comparative example is 0.8, as long as it is at least less than 0.8, it can exhibit an excellent unnecessary vibration attenuation effect compared to the comparative example. Note that the displacement amplitude magnification (gain) is preferably less than 0.6, more preferably less than 0.4, and even more preferably less than 0.2. Thereby, the unnecessary vibration attenuation effect can be exhibited more remarkably.

[0053] Note that from Fig. 8, to make the displacement amplitude magnification less than 0.8, f0 / f1 may be made less than 0.7; to make the displacement amplitude magnification less than 0.6, f0 / f1 may be made less than 0.65; to make the displacement amplitude magnification less than 0.4, f0 / f1 may be made less than 0.55; and to make the displacement amplitude magnification less than 0.2, f0 / f1 may be made less than 0.4. That is, f0 / f1 is preferably less than 0.7, more preferably less than 0.65, even more preferably less than 0.55, and still more preferably less than 0.4.

[0054] The vibration device 1 has been described above. As described above, when the three axes orthogonal to each other are defined as the A-axis, B-axis, and C-axis, the vibration device 1 includes a vibration element 6 having drive arms 75, 76, 77, 78 as vibration arms that bend and vibrate along a plane parallel to the A-axis and B-axis and along the A-axis, and a support substrate 4 arranged side by side with the vibration element 6 along the C-axis. The vibration structure 10 has a support substrate 4. The support substrate 4 includes a base portion 40 that supports the vibration element 6, a support portion 41 that supports the base portion 40, and beam portions 42, 43, 44, 45 that connect the base portion 40 and the support portion 41. When the resonance frequency of the vibration along the B-axis of the vibration structure 10 is f0 and the drive frequency of the vibration element 6 is f1, f0 < f1. By setting f0 < f1 in this way, a difference is generated between the frequency of unnecessary vibration, which is substantially f1, and the resonance frequency f0, and resonance of the vibration system 100 due to unnecessary vibration can be suppressed. Therefore, the unnecessary vibration of the vibration element 6 can be effectively attenuated by the support substrate 4.

[0055] Also, as described above, when the spring constant of the elastic deformation along the A-axis of the beam portions 42, 43, 44, 45 is Ka and the spring constant of the elastic deformation along the B-axis of the beam portions 42, 43, 44, 45 is Kb, Ka > Kb. Also, in a plan view from the direction along the C-axis, the support portion 41 includes a first support portion 411 located on one side along the A-axis with respect to the vibration element 6, which is the plus side in this embodiment, and a second support portion 412 located on the other side along the A-axis, which is the minus side in this embodiment. By arranging the first and second support portions 411, 412 on both sides of the vibration element 6 in this way, the vibration element 6 can be supported in a stable posture. Therefore, the vibration characteristics of the vibration element 6 are stabilized. Also, by arranging the first and second support portions 411, 412 side by side along the A-axis, it becomes easier to form the beam portions 42, 43, 44, 45 that connect the base portion 40 and the first and second support portions 411, 412 longer along the A-axis than along the B-axis, and it becomes easier to satisfy the relationship of Ka > Kb. Therefore, the design freedom of the support substrate 4 is improved.

[0056] Also, as described above, the vibration element 6 includes an element base 70, detection arms 71 and 72 extending from the element base 70 along the B axis on both sides, a first connection arm 73 extending from the element base 70 along the A axis, a second connection arm 74 extending from the element base 70 along the A axis in a direction opposite to the direction in which the first connection arm 73 extends, drive arms 75 and 76 as vibration arms extending from the tip of the first connection arm 73 along the B axis on both sides, and drive arms 77 and 78 as vibration arms extending from the tip of the second connection arm 74 along the B axis on both sides. The element base 70 is fixed to the base 40 via the 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 attenuated, and the high-precision vibration device 1 can be realized.

[0057] Also, as described above, the displacement amplitude magnification (gain) of the vibration of the vibration element 6 along the B axis at the drive frequency f1 is less than 0.8. Thereby, the unnecessary vibration of the vibration element 6 can be more effectively attenuated by the support substrate 4.

[0058] Also, as described above, the vibration element 6 includes a vibration substrate 7 and electrodes 8 disposed on the vibration substrate 7. The vibration substrate 7 and the support substrate 4 are composed of crystal substrates with the same cut angle. Thereby, the thermal expansion coefficients of the support substrate 4 and the vibration substrate 7 can be made equal. Therefore, substantially no thermal stress is generated between the support substrate 4 and the vibration substrate 7 due to the difference in their thermal expansion coefficients, and the vibration element 6 is less likely to be subjected to stress. Therefore, the degradation and variation of the vibration characteristics of the vibration element 6 can be more effectively suppressed.

[0059] Also, as described above, in a plan view from the direction along the C axis, the support substrate 4 overlaps with the drive arms 75, 76, 77, and 78. Therefore, the support substrate 4 functions as a stopper for suppressing excessive deformation of the drive arms 75 to 78 in the C axis direction, and breakage of the vibration element 6 can be effectively suppressed.

[0060] Also, 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 ωc. Thereby, the vibration device 1 can be mounted on a wide range of electronic devices, and the vibration device 1 with high convenience is obtained.

[0061] In the first embodiment as described above, the support substrate 4 is located between the vibration element 6 and the circuit element 3, and supports the vibration element 6 from below, that is, from the C-axis minus side. However, the vibration element 6 may be located between the support substrate 4 and the circuit element 3, and the support substrate 4 may support the vibration element 6 from above, that is, from the C-axis plus side. Also, in the first embodiment, the support substrate 4 is fixed to the bottom surface of the recess 211a of the base 21 via the joining member B1. However, the support substrate 4 may be fixed to the circuit element 3 via a joining member.

[0062] <Second Embodiment> FIG. 9 is a plan view showing the vibration device of the second embodiment.

[0063] This embodiment is the same as the first embodiment described above except that the orientation of the vibration element 6 is different. In the following description, regarding this embodiment, the differences from the above-described embodiments will be mainly described, and the description of the same matters will be omitted. Also, in FIG. 9, the same components as those in the above-described embodiments are denoted by the same reference numerals.

[0064] As shown in Fig. 9, in the support substrate 4 of the present embodiment, each part other than the vibration element 6, that is, the package 2, the support substrate 4, and the circuit element 3 are arranged by rotating 90° around the C axis from the first embodiment described above. That is, the support substrate 4 includes a base 40, a support portion 41 that supports the base 40 and is arranged to be divided on both sides along the B axis of the base 40, including a first support portion 411 and a second support portion 412, a pair of beam portions 42 and 43 connecting the base 40 and the first support portion 411, and a pair of beam portions 44 and 45 connecting the base 40 and the second support portion 412. The element base 70 of the vibration element 6 is fixed to the base 40 via a conductive bonding member B2, and the first support portion 411 and the second support portion 412 are respectively fixed to the bottom surface of the recess 211a via a bonding member B1. Even with such a configuration, as shown by the curve Q2 in Fig. 7 described above, the support substrate 4 can effectively attenuate the unnecessary vibration of the vibration element 6. Note that the support substrate 4 has not been rotated around the C axis with respect to the orientation of the crystal axis and remains as in the first embodiment described above.

[0065] According to such a vibration device 1 of the present embodiment, the support substrate 4 can effectively attenuate the unnecessary vibration of the vibration element 6, and by arranging the first and second support portions 411 and 412 on both sides of the vibration element 6, the vibration element 6 can be supported in a stable posture. Therefore, the vibration characteristics of the vibration element 6 are stabilized.

[0066] <Third Embodiment> Fig. 10 is a plan view showing the support substrate included in the vibration device of the third embodiment.

[0067] This embodiment is the same as the first embodiment described above except that the configuration of the support substrate 4 is different. In the following description, regarding this embodiment, the differences from the above-described embodiments will be mainly described, and the description of the same matters will be omitted. Also, in Fig. 10, the same reference numerals are given to the same configurations as those in the above-described embodiments.

[0068] As shown in FIG. 10, the support substrate 4 of the present embodiment has a gimbal shape. That is, the support substrate 4 has a base portion 46 located at the center and to which the vibration element 6 is fixed via a joining 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 joining member B1, and a beam portion 48 located between the base portion 46 and the support portion 47 and connecting these.

[0069] Further, the beam portion 48 has a frame portion 481 in a frame shape that is located between the base portion 46 and the support portion 47 and surrounds the base portion 46, a first beam portion 482 that connects the base portion 46 and the frame portion 481, and a second beam portion 483 that connects 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 along the B axis, and its central axis J2 is 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 direction along the A axis, and its central axis J1 is along the B axis. That is, the central axes J1 and J2 are orthogonal, and their intersection point substantially coincides with the center O4 of the support substrate 4. However, the central axes J1 and J2 may intersect at an angle greater than 0° and less than 90°, and their intersection point may be deviated from the center O4.

[0070] Further, the support portion 47 has a rectangular frame shape and, in a plan view, has a first support portion 471 located on the plus side of the A axis with respect to the vibration element 6 and a second support portion 472 located on the minus side of the A axis. The first support portion 471 and the second support portion 472 are each fixed to the bottom surface of the concave portion 211a via a joining member B1.

[0071] Even with such a configuration, the same operational effects as those of the first embodiment described above can be exhibited. In the present embodiment, the support portion 47 has a frame shape, but it is not limited to this. For example, a part of the circumferential direction may be missing and it may have a C shape. The same applies to the frame portion 481.

[0072] <Fourth Embodiment> FIG. 11 is a perspective view showing a personal computer according to the fourth embodiment.

[0073] The personal computer 1100 as an electronic device shown in FIG. 11 is composed of a main body 1104 equipped with a keyboard 1102 and a display unit 1106 equipped with a display section 1108. The display unit 1106 is rotatably supported with respect to the main body 1104 via a hinge structure. Further, the personal computer 1100 incorporates a vibration device 1 as a physical quantity sensor and a signal processing circuit 1110 that performs signal processing, that is, controls each part, based on an output signal from the vibration device 1.

[0074] Thus, the personal computer 1100 as an electronic device includes the vibration device 1 and the signal processing circuit 1110 that performs signal processing based on the output signal of the vibration device 1. Therefore, the effects of the vibration device 1 described above can be enjoyed, and high reliability can be exhibited.

[0075] <Fifth Embodiment> FIG. 12 is a perspective view showing a mobile phone according to the fifth embodiment.

[0076] The mobile phone 1200 as an electronic device shown in FIG. 12 includes an antenna (not shown), a plurality of operation buttons 1202, a receiver 1204, and a transmitter 1206, and a display section 1208 is disposed between the operation buttons 1202 and the receiver 1204. Further, the mobile phone 1200 incorporates a vibration device 1 as a physical quantity sensor and a signal processing circuit 1210 that performs signal processing, that is, controls each part, based on an output signal from the vibration device 1.

[0077] Thus, the mobile phone 1200 as an electronic device includes the vibration device 1 and the signal processing circuit 1210 that performs signal processing based on the output signal of the vibration device 1. Therefore, the effects of the vibration device 1 described above can be enjoyed, and high reliability can be exhibited.

[0078] <Sixth Embodiment> FIG. 13 is a perspective view showing a digital still camera according to the sixth embodiment.

[0079] As shown in FIG. 13, a digital still camera 1300 as an electronic device includes a case 1302, and a display unit 1310 is provided on the back surface of the case 1302. The display unit 1310 is configured to perform display based on an imaging signal by a CCD, and functions as a finder that displays a subject as an electronic image. Further, on the front side of the case 1302, a light receiving unit 1304 including an optical lens, a CCD, etc. is provided. When a photographer checks the subject image displayed on the display unit 1310 and presses the shutter button 1306, the imaging signal of the CCD at that time is transferred and stored in the memory 1308. Further, 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, control of each part, based on an output signal from the vibration device 1.

[0080] As described above, the digital still camera 1300 as an electronic device includes the vibration device 1 and the signal processing circuit 1312 that performs signal processing based on the output signal of the vibration device 1. Therefore, the effects of the vibration device 1 described above can be enjoyed, and high reliability can be exhibited.

[0081] In addition to the personal computer 1100, the mobile phone 1200, and the digital still camera 1300 described above, the electronic device including the vibration device 1 includes, for example, a smartphone, a tablet terminal, a watch including a smartwatch, an inkjet ejection device such as an inkjet printer, a wearable terminal such as an HMD (head-mounted display), a television, a video camera, a video tape recorder, a car navigation device, a pager, an electronic notebook, an electronic dictionary, a calculator, an electronic game device, a word processor, a workstation, a videophone, a security television monitor, electronic binoculars, a POS terminal, an electronic thermometer, a blood pressure monitor, a blood glucose meter, an electrocardiogram measuring device, a medical device such as an ultrasonic diagnostic device, an electronic endoscope, a fish finder, various measuring devices, instruments such as a vehicle, an aircraft, and a ship, a base station for a mobile terminal, a flight simulator, etc. may also be used.

[0082] <Seventh Embodiment> FIG. 14 is a perspective view showing an automobile according to the seventh embodiment.

[0083] An automobile 1500 as a moving body shown in FIG. 14 includes systems 1502 such as an engine system, a brake system, and a keyless entry system. Further, the automobile 1500 incorporates a vibration device 1 as a physical quantity sensor and a signal processing circuit 1510 that performs signal processing, that is, controls the system 1502, based on an output signal from the vibration device 1.

[0084] As described above, the automobile 1500 as a moving body includes the vibration device 1 and a signal processing circuit 1510 that performs signal processing based on an oscillation signal as an output signal of the vibration device 1. Therefore, the effects of the vibration device 1 described above can be enjoyed, and high reliability can be exhibited.

[0085] Note that the moving body including the vibration device 1 may be, for example, a robot, a drone, a two-wheeled vehicle, an aircraft, a ship, a train, a rocket, a spacecraft, etc., in addition to the automobile 1500.

[0086] As described above, the vibration device, the electronic device, and the moving body of the present invention have been described based on the illustrated embodiments. However, the present invention is not limited to this, and the configuration of each part can be replaced with any configuration having the same function. Further, any other arbitrary components may be added to the present invention. Also, the embodiments may be combined as appropriate.

Explanation of Reference Numerals

[0087] 1…Vibration device, 10…Vibration structure, 100…Vibration system, 2…Package, 21…Base, 211…Recess, 211a, 211b, 211c…Recesses, 22…Lid, 23…Joining member, 241, 242…Internal terminals, 243…External terminal, 3…Circuit element, 4…Support substrate, 40…Base portion, 41…Support portion, 411…First support portion, 412…Second support portion, 42…Beam portion, 421…Flexure portion, 43…Beam portion, 431…Flexure portion, 44…Beam portion, 441…Flexure portion, 45…Beam portion, 451…Flexure portion, 46…Base portion, 47…Support portion, 471…First support portion, 472…Second support portion, 48…Beam portion, 481…Frame portion, 482…First beam portion, 483…Second beam portion, 5…Wiring, 511, 512…Terminals, 513…Lead wiring, 521, 522…Terminals, 523…Lead wiring, 531, 532…Terminals, 533…Lead wiring, 541, 542…Terminals, 543…Lead wiring, 551, 552…Terminals, 553…Lead wiring, 561, 562…Terminals, 563…Lead wiring, 6…Vibration element, 7…Vibration substrate, 70…Element base portion, 701~706…Terminals, 71…Detection arm, 711…Wide portion, 72…Detection arm, 721…Wide portion, 73…First connecting arm, 74…Second connecting arm, 75…Drive arm, 751…Wide portion, 76…Drive arm, 761…Wide portion, 77…Drive arm, 771…Wide portion, 78…Drive arm, 781…Wide portion, 8…Electrode, 81…Drive signal electrode, 82…Drive ground electrode, 83…First detection signal electrode, 84…First detection ground electrode, 85…Second detection signal electrode, 86…Second detection ground electrode, 1100…Personal computer, 1102…Keyboard, 1104…Main body portion, 1106…Display unit, 1108…Display portion, 1110…Signal processing circuit, 1200…Mobile phone, 1202…Operation button, 1204…Microphone, 1206…Speaker, 1208…Display portion, 1210…Signal processing circuit, 1300…Digital still camera, 1302…Case, 1304…Light receiving unit, 1306…Shutter button, 1308…Memory, 1310…Display portion, 1312…Signal processing circuit, 1500…Automobile, 1502…System, 1510…Signal processing circuit, B1, B2…Joining members, BW…Bonding wire, D, E…Arrows, J1, J2…Central axes, O4…Center, Q1~Q3…Curves, S…Internal space, f0…Resonance frequency, f1…Drive frequency, fd…Frequency, ωc…Angular velocity

Claims

1. When three axes orthogonal to each other are defined as the A-axis, the B-axis, and the C-axis, a vibration element including an element base and a driving arm extending in the B-axis direction along the B-axis, a support substrate including a base overlapping the element base in a plan view from the C-axis direction along the C-axis, and a support portion connected to the base via a beam portion, and including: wherein the driving arm bends and vibrates in the A-axis direction along the A-axis, and in the plan view, overlaps the beam portion, and the element base is fixed to the base via a joining member, and the beam portion includes a bent portion, characterized by a vibration device.

2. In claim 1, the bent portion meanders in an S shape in the plan view, characterized by a vibration device.

3. In claim 2, the vibration element includes a detection arm extending in the B-axis direction from the element base, characterized by a vibration device.

4. In claim 3, the vibration element includes a first connecting arm extending from the plus side of the A-axis of the element base, and a second connecting arm extending from the minus side of the A-axis of the element base, and includes: wherein the driving arm includes a first driving arm extending in the B-axis direction from the first connecting arm, and a second driving arm extending in the B-axis direction from the second connecting arm, characterized by a vibration device.

5. In claim 4, in the plan view, The support part is a first support part arranged on the plus side of the A axis, and a second support part arranged on the minus side of the A axis, and includes the base part is arranged between the first support part and the second support part, which is characterized in that it is a vibration device. **Claim 6** In claim 4, in the plan view, the support part is a first support part arranged on the plus side of the B axis, and a second support part arranged on the minus side of the B axis, and includes the base part is arranged between the first support part and the second support part, which is characterized in that it is a vibration device. **Claim 7** In claim 4, in the plan view, the support part surrounds the base part, the beam part is arranged between the base part and the support part, a frame part surrounding the base part, a first beam part connecting the base part and the frame part, and a second beam part connecting the support part and the frame part, and includes a vibration device characterized by this. **Claim 8** In claim 7, the support part is a first support part arranged on the plus side of the A axis, and a second support part arranged on the minus side of the A axis, and includes a vibration device characterized by this. **Claim 9** In claim 8, the support part is frame-shaped, which is characterized in that it is a vibration device. **Claim 10** In any one of claims 1 to 9, when the resonance frequency of the driving vibration mode is f1, and the frequency of the unwanted vibration is f0, a vibration device characterized by satisfying f0 < f1. **Claim 11** An electronic device comprising: the vibration device according to any one of claims 1 to 10, and a signal processing circuit that performs signal processing based on an output signal of the vibration device. **Claim 12** A moving body comprising: the vibration device according to any one of claims 1 to 10, and a signal processing circuit that performs signal processing based on an output signal of the vibration device. ​

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