Vibration device and electronic device

Abstract

A vibration device and an electronic device are provided, which have excellent detection characteristics. The vibration device includes a vibration element, a base, and a support member that supports the vibration element with respect to the base. In addition, when viewed from above in the thickness direction of the support member, the support member has a frame-shaped frame, a base disposed outside the frame and fixed to the base, an element holder disposed inside the frame and on which the vibration element is mounted, a pair of first beams extending from the element holder in a first direction and connecting the element holder and the frame, and a pair of second beams extending from the frame in a second direction different from the first direction and connecting the frame and the base. And, when viewed from above, when the length of the first beam in the first direction is set to L1 (μm) and the width W of the first beam in a direction perpendicular to the first direction is set to W1 (μm), W1² / L1 < 30 is satisfied.

Description

[0001] This application is a divisional application of a patent application for an invention named "Vibration Device" with an application date of August 27, 2020 and an application number of 202010875967.X. Technical Field

[0002] The present invention relates to a vibration device. Background Art

[0003] A vibration device having a circuit element, a vibration element, and a relay substrate for fixing the vibration element to the circuit element is described in Patent Document 1. In addition, the relay substrate forms a gimbal structure and has a frame-shaped first portion fixed to the circuit element, a frame-shaped second portion disposed inside the first portion, a third portion disposed inside the second portion and having the vibration element fixed thereto, a first beam connecting the first portion and the second portion, and a second beam connecting the second portion and the third portion. With such a relay substrate, the transmission of stress to the vibration element is suppressed. In addition, in Patent Document 2, as a support structure for a gyroscope element, a structure in which the gyroscope element is supported above a TAB substrate by inner leads is described.

[0004] Patent Document 1: Japanese Patent Application Laid-Open No. 2019-102858

[0005] Patent Document 2: Japanese Patent Application Laid-Open No. 2017-026336

[0006] When the gyroscope element described in Patent Document 2 is mounted on the gimbal-shaped relay substrate described in Patent Document 1 instead of the support structure described in that document, depending on the size of the second beam, the rigidity of the second beam about the Z-axis, i.e., the detection axis of the gyroscope element, becomes too high. If the rigidity of the second beam about the Z-axis becomes too high, the detection vibration of the gyroscope element is hindered, and the detection sensitivity of the gyroscope element may decrease. Summary of the Invention

[0007] The vibration device of this application example is characterized by including: a vibration element that detects vibration according to a physical quantity around a detection axis; a base; and a support member that supports the vibration element relative to the base. When viewed from above in the thickness direction of the support member, the support member has: a frame-shaped framework; a base that is disposed outside the framework and fixed to the base; an element holder that is disposed inside the framework and on which the vibration element is mounted; a pair of first beams that extend from the element holder along a first direction and connect the element holder and the framework; and a pair of second beams that extend from the framework along a second direction different from the first direction and connect the framework and the base. When, in the top view, the length of the first beam in the first direction is set to L1 μm and the width W of the first beam in a direction perpendicular to the first direction is set to W1 μm, W1 2 / L1 < 30.

[0008] In the vibration device of this application example, it is preferable that W1 2 / L1 < 12.5.

[0009] In the vibration device of this application example, preferably, when three mutually perpendicular axes are set as the A axis, the B axis, and the C axis, the thickness direction of the support member is along the C axis, and the vibration element has: an element base that is fixed to the element holder; a pair of detection arms that extend from the element base along the B axis; a pair of connection arms that extend from the element base along the A axis; a pair of drive arms that extend from the end of one of the connection arms along the B axis; and a pair of drive arms that extend from the end of the other connection arm along the B axis.

[0010] In the vibration device of this application example, preferably, the first direction is along the A axis and the second direction is along the B axis.

[0011] In the vibration device of this application example, preferably, when viewed from above in the direction along the C axis, the element holder and the element base have the same shape.

[0012] In the vibration device of this application example, preferably, the support member has a pair of third beams that extend from the framework along the first direction and connect the framework and the base, and the pair of third beams and the pair of first beams are arranged in a straight line. Description of the Drawings

[0013] Figure 1 is a cross-sectional view showing the vibration device of the first embodiment.

[0014] Figure 2is a top view showing Figure 1 of a vibration device.

[0015] Figure 3 is a top view showing Figure 1 a vibration element included in the vibration device.

[0016] Figure 4 is a cross-sectional view taken along line D-D in Figure 3 .

[0017] Figure 5 is a cross-sectional view taken along line E-E in Figure 3 .

[0018] Figure 6 is a schematic diagram for explaining Figure 3 driving of the vibration element.

[0019] Figure 7 is a schematic diagram for explaining Figure 3 driving of the vibration element.

[0020] Figure 8 is a top view of a support member.

[0021] Figure 9 is a graph showing the relationship between 2 W1 / L1 and sensitivity.

[0022] Figure 10 is a top view of a vibration device according to a second embodiment.

[0023] Figure 11 is a top view of a support member included in a vibration device according to a third embodiment.

[0024] Reference Numeral Explanation

[0025] 1: Vibration device; 2: Package; 21: Base; 211, 211a - 211c: Recesses; 22: Cover; 23: Joining member; 241, 242: Internal terminals; 243: External terminal; 3: Circuit element; 4: Support member; 41: Frame; 411 - 414: Edges; 42: Base; 421 - 424: Edges; 43: Element holder; 44: First beam; 45: Second beam; 46: Third beam; 6: Vibration element; 7: Vibration substrate; 70: Element base; 701 - 706: Terminals; 71, 72: Detection arms; 73, 74: Connection arms; 75 - 78: Driving arms; 8: Electrode; 81: Driving signal electrode; 82: Driving ground electrode; 83: First detection signal electrode; 84: First detection ground electrode; 85: Second detection signal electrode; 86: Second detection ground electrode; a, b: Arrows; B1, B2: Joining members; BW: Bonding wire; La: Imaginary straight line; Lb: Imaginary straight line; L1, L2: Lengths; O: Center; S: Internal space; W1, W2: Widths; ωc: Angular velocity. Detailed implementation mode

[0026] Hereinafter, the vibration device of this application example will be described in detail based on the embodiments shown in the drawings.

[0027] <First Embodiment>

[0028] Figure 1 It is a cross - sectional view showing the vibration device of the first embodiment. Figure 2 It shows Figure 1 a top view of the vibration device. Figure 3 It shows Figure 1 a top view of the vibration element included in the vibration device. Figure 4 It is a cross - sectional view along the D - D line in Figure 3 the above. Figure 5 It is a cross - sectional view along the E - E line in Figure 3 the above. Figure 6 And Figure 7 are diagrams for explaining Figure 3 the driving of the vibration element. Figure 8 It is a top view of the support member. Figure 9 It shows the relationship between W1 2 / L1 and the sensitivity.

[0029] In addition, for ease of explanation, three mutually perpendicular axes, namely the A - axis, B - axis, and C - axis, are shown in Figures 1 to 8 the above. And hereinafter, the end side of the arrow of each axis is also referred to as the "positive side", and the opposite side is also referred to as the "negative side". Also, the positive side and the negative side are collectively referred to as the "two sides". In addition, 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, looking down from the thickness direction of the support member 4, that is, along the C - axis direction, is also simply referred to as "looking down".

[0030] Figure 1 The vibration device 1 shown is a physical quantity sensor that detects the angular velocity ωc with the C-axis as the detection axis. In this way, 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 a vibration device 1 with high convenience and high demand can be obtained. Such a vibration device 1 has a package 2, a circuit element 3 housed in the package 2, a support member 4, and a vibration element 6.

[0031] The package 2 has: a base 21 having a recess 211 that opens on the upper surface; and a lid 22 that closes the opening of the recess 211 and is joined to the upper surface of the base 21 via a joining member 23. An internal space S is formed inside the package 2 by the recess 211, and the circuit element 3, the support member 4, and the vibration element 6 are respectively 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 alloy. However, there is no particular limitation on the constituent materials of the base 21 and the lid 22 respectively.

[0032] The internal space S is airtight and in a reduced-pressure state, preferably in a state closer to a vacuum. Thereby, the viscous resistance is reduced, and the vibration characteristics of the vibration element 6 are improved. However, the environment of the internal space S is not particularly limited, and for example, it can also be in an atmospheric pressure state or a pressurized state.

[0033] In addition, the recess 211 is composed of a plurality of recesses, and has 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 an opening width smaller than that of the recess 211a, and a recess 211c that opens on the bottom surface of the recess 211b and has an opening width smaller than that of the recess 211b. And, the support member 4 is fixed to the bottom surface of the recess 211a in a state of supporting the vibration element 6, and the circuit element 3 is fixed to the bottom surface of the recess 211c.

[0034] In addition, as Figure 2 shown, in the internal space S, the vibration element 6, the support member 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 member 4, and the circuit element 3 are arranged along the C-axis. Thereby, the planar expansion of the package 2 in the direction along the A-axis and the direction along the B-axis can be suppressed, and miniaturization of the vibration device 1 can be achieved. In addition, the support member 4 is located between the vibration element 6 and the circuit element 3, and supports the vibration element 6 from the lower side, that is, the negative side of the C-axis.

[0035] In addition, as Figure 1 and Figure 2As shown, a plurality of internal terminals 241 are disposed on the bottom surface of the recess 211a, a plurality of internal terminals 242 are disposed on the bottom surface of the recess 211b, and a plurality of external terminals 243 are disposed on the lower surface of the base 21. These internal terminals 241, 242, and external terminals 243 are electrically connected via wirings (not shown) formed in the base 21. Further, the internal terminal 241 is electrically connected to the vibration element 6 via conductive bonding members B1, B2, and the support member 4, and the internal terminal 242 is electrically connected to the circuit element 3 via the bonding wire BW.

[0036] The vibration element 6 is an angular velocity sensor element that detects the angular velocity ωc about the C-axis as a physical quantity sensor element. As Figure 3 shown, 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 formed of a Z-cut quartz substrate. The Z-cut quartz substrate extends in the X-Y plane defined by the crystal axes of quartz, i.e., the X-axis as the electrical axis and the Y-axis as the mechanical axis, and has a thickness in the direction along the Z-axis as the optical axis.

[0037] The vibration substrate 7 has: an element base 70 located at the central portion; a pair of detection arms 71, 72 extending from the element base 70 to both sides in the direction along the B-axis; a pair of connection arms 73, 74 extending from the element base 70 to both sides in the direction along the A-axis; a pair of drive arms 75, 76 extending from the ends of the connection arm 73 to both sides in the direction along the B-axis; and a pair of drive arms 77, 78 extending from the ends of the connection arm 74 to both sides in the direction along the B-axis. By using the vibration substrate 7 having such a shape, a vibration element 6 with excellent vibration balance can be obtained.

[0038] Further, as Figure 4 and Figure 5 shown, the drive arms 75 to 78 have a groove opening on the upper surface and a groove opening on the lower surface, and have a substantially H-shaped cross-sectional shape. Further, the detection arms 71, 72 may also have a groove opening on the upper surface and a groove opening on the lower surface, and have a substantially H-shaped cross-sectional shape.

[0039] As Figure 3As shown, 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 both side surfaces of the drive arms 75 and 76, and on the upper and lower surfaces of the drive arms 77 and 78. On the other hand, the drive ground electrode 82 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. In addition, 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.

[0040] In addition, these electrodes 81 to 86 are respectively wound around to the lower surface of the element base 70. And, as Figure 3 shown, on the lower surface of the element base 70, there are disposed 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.

[0041] Such a vibration 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 as indicated by the arrows in Figure 6 . Hereinafter, this drive mode is referred to as the drive vibration mode. And, in a state where the vibration element 6 is driven in the drive vibration mode, if an angular velocity ωc is applied to the vibration element 6, a detection vibration mode as shown in Figure 7 is newly excited. In the detection vibration mode, a Coriolis force acts on the drive arms 75 to 78, exciting vibration in the direction indicated by the arrow b, and the detection arms 71 and 72 generate detection vibration based on bending vibration in the direction indicated by the arrow a in response to this vibration. This detection vibration mode can be utilized to take out the charge generated on the detection arm 71 between the first detection signal electrode 83 and the first detection ground electrode 84 as the first detection signal, and take out the charge generated on the detection arm 72 between the second detection signal electrode 85 and the second detection ground electrode 86 as the second detection signal, and detect the angular velocity ωc based on the first detection signal and the second detection signal.

[0042] Return Figure 1, the circuit component 3 is fixed to the bottom surface of the recess 211c. The circuit component 3 includes a drive circuit and a detection circuit for driving the vibration element 6 and detecting the angular velocity ωc applied to the vibration element 6. However, there is no particular limitation on the circuit component 3. For example, it may also include other circuits such as a temperature compensation circuit.

[0043] In addition, as Figure 1 shown, the support member 4 is interposed between the base 21 and the vibration element 6. The support member 4 mainly has the function of absorbing and alleviating the stress generated by the deformation of the base 21 so that the stress is not easily transmitted to the vibration element 6.

[0044] Such a support member 4 has a gimbal structure. Specifically, as Figure 2 and Figure 8 shown, the support member 4 has: a frame 41 that is box-shaped when viewed from above in the direction along the C axis; a box-shaped base 42 disposed outside the frame 41 and fixed to the base 21; an element holder 43 disposed inside the frame 41 and on which the vibration element 6 is mounted; a pair of first beams 44, 44 that extend from the element holder 43 to both sides in the direction along the A axis and connect the element holder 43 and the frame 41; and a pair of second beams 45, 45 that extend from the frame 41 to both sides in the direction along the B axis and connect the frame 41 and the base 42. In addition, hereinafter, when viewed from above in the direction along the C axis, a virtual straight line passing through the center O of the element holder 43 and parallel to the A axis is defined as the virtual straight line La, and a virtual straight line passing through the center O and parallel to the B axis is defined as the virtual straight line Lb. In the present embodiment, the frame 41, the base 42, the element holder 43, the pair of first beams 44, 44, and the pair of second beams 45, 45 are all arranged line-symmetrically with respect to the virtual straight line La and line-symmetrically with respect to the virtual straight line Lb, but it is not limited thereto.

[0045] The frame 41 has a rectangular frame shape and has a pair of edge portions 411, 412 extending in the direction along the A axis and a pair of edge portions 413, 414 extending in the direction along the B axis. Similarly, the base 42 has a rectangular frame shape and has a pair of edge portions 421, 422 extending in the direction along the A axis and a pair of edge portions 423, 424 extending in the direction along the B axis. In particular, in the present embodiment, when viewed from above in the direction along the C axis, the edge portion 413 of the frame 41 overlaps with the drive arms 75, 76 of the vibration element 6, and the edge portion 414 of the frame 41 overlaps with the drive arms 77, 78 of the vibration element 6.

[0046] In addition, a pair of first beams 44, 44 are located on both sides of the component cage 43 in the direction along the A axis, and connect the component cage 43 and the frame 41 in such a way as to support the component cage 43 at both ends. In addition, the pair of first beams 44, 44 are respectively arranged in a straight line along the imaginary straight line La. On the other hand, a pair of second beams 45, 45 are located on both sides of the frame 41 in the direction along the B axis, and connect the frame 41 and the base 42 in such a way as to support the frame 41 at both ends. In addition, the pair of second beams 45, 45 are respectively arranged in a straight line along the imaginary straight line Lb. That is, one second beam 45 connects the central portions of the edge portions 411, 421 in the extending direction to each other, and the other second beam 45 connects the central portions of the edge portions 412, 422 in the extending direction to each other.

[0047] In this way, by making the extending directions of the first beams 44, 44 perpendicular to the extending directions of the second beams 45, 45, the support member 4 can more effectively absorb and relieve stress. In addition, by making the first beams 44, 44 extend in the same direction as the extending directions of the connecting arms 73, 74, that is, in the direction along the A axis, it is possible to easily ensure a length similar to that of the connecting arms 73, 74. Therefore, it is easy to increase the length of the first beams 44, 44, that is, L1 described later. In particular, as described above, in the present embodiment, when viewed from above in the direction along the C axis, the edge portion 413 of the frame 41 overlaps with the drive arms 75, 76, and the edge portion 414 of the frame 41 overlaps with the drive arms 77, 78. Therefore, the lengths of the first beams 44, 44 are substantially equal to the lengths of the connecting arms 73, 74.

[0048] In such a support member 4, the element base 70 of the vibration element 6 is fixed to the upper surface of the component cage 43 via the conductive bonding member B2, and the edge portions 423, 424 of the base 42 are fixed to the bottom surface of the recess 211a via the conductive bonding member B1. In this way, by sandwiching the support member 4 between the vibration element 6 and the base 21, the support member 4 can absorb and relieve the stress transmitted from the base 21 so that the stress is not easily transmitted to the vibration element 6. Therefore, it is possible to effectively suppress the deterioration and variation of the vibration characteristics of the vibration element 6.

[0049] In addition, as the bonding components B1 and B2, as long as they have both conductivity and bondability, there is no particular limitation. For example, various metal bumps such as gold bumps, silver bumps, copper bumps, solder bumps, etc., and conductive adhesives in which conductive fillers such as silver fillers are dispersed in various adhesives of polyimide type, epoxy type, silicone type, acrylic type, etc. can be used. If the former metal bumps are used as the bonding components B1 and B2, the generation of gas from the bonding components B1 and B2 can be suppressed, and the environmental change in the internal space S, especially the increase in pressure, can be effectively suppressed. On the other hand, if the latter conductive adhesive is used as the bonding components B1 and B2, the bonding components B1 and B2 become relatively soft, and the bonding components B1 and B2 can also absorb and relieve the above stress.

[0050] In the present embodiment, a conductive adhesive is used as the bonding component B1, and a metal bump is used as the bonding component B2. By using a conductive adhesive as the bonding component B1 that joins the support 4 of different types of materials and the base 21, the thermal stress generated due to the difference in the coefficient of thermal expansion between the support 4 and the base 21 can be effectively absorbed and relieved by the bonding component B1. On the other hand, the support 4 and the vibration element 6 are joined by six bonding components B2, and these six bonding components B2 are arranged in a relatively narrow area. Therefore, by using metal bumps as the bonding components B2, the infiltration spread such as that of a conductive adhesive can be suppressed, and the contact between the bonding components B2 can be effectively suppressed.

[0051] Such a support 4 is made of a quartz substrate. Thus, by making the support 4 made of a quartz substrate in the same way as the vibration substrate 7, the coefficient of thermal expansion of the support 4 and the vibration substrate 7 can be made substantially equal. Therefore, thermal stress caused by the difference in the coefficient of thermal expansion between each other hardly occurs between the support 4 and the vibration substrate 7, and the vibration element 6 is less likely to be affected by stress. Therefore, the decrease and variation of the vibration characteristics of the vibration element 6 can be more effectively suppressed.

[0052] In particular, the support 4 is made 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 made of a Z-cut quartz substrate, the support 4 is also made of a Z-cut quartz substrate. In addition, the orientation of the crystal axis of the support 4 is the same as the orientation of the crystal axis of the vibration substrate 7. That is, in the support 4 and the vibration substrate 7, the X-axis is the same, the Y-axis is the same, and the Z-axis is the same. The coefficient of thermal expansion of quartz is different in each direction along the X-axis direction, the Y-axis direction, and the Z-axis direction. Therefore, by making the support 4 and the vibration substrate 7 have the same cut angle and making the orientations of their crystal axes the same, the above-mentioned thermal stress is less likely to occur between the support 4 and the vibration substrate 7. Therefore, the vibration element 6 is less likely to be affected by stress, and the decrease and variation of its vibration characteristics can be more effectively suppressed.

[0053] In addition, as the support member 4, it is not limited thereto. For example, the chamfer angle may be the same as that of the vibrating substrate 7, but the crystal axis direction may be different from that of the vibrating substrate 7. In addition, the support member 4 may be formed of a quartz substrate with a different chamfer angle from the vibrating substrate 7. In addition, the support member 4 may not be formed of a quartz substrate. In this case, for example, it may be formed of a silicon substrate, a resin substrate, etc. In this case, the constituent material of the support member 4 is preferably a material with a smaller difference in thermal expansion coefficient from quartz than the difference in thermal expansion coefficient between the constituent material of the base 21 and quartz.

[0054] In addition, a wiring pattern (not shown) that electrically connects the vibration element 6 and the internal terminal 241 is disposed on the support member 4. The wiring pattern electrically connects each of the terminals 701 to 706 to the corresponding internal terminal 241.

[0055] Next, the dimensions of the pair of first beams 44, 44 will be described. As Figure 8 shown, when the length of each first beam 44 in the direction along the A axis is set to length L1 (μm) and the length of each first beam 44 in the direction along the B axis is set to width W1 (μm), each of the first beams 44, 44 preferably satisfies W1 2 / L1 < 30, and particularly preferably satisfies W1 2 / L1 < 12.5. By satisfying such a relationship, the length L1 becomes sufficiently long relative to the width W1, and each of the first beams 44, 44 is easily elastically deformed in the direction along the B axis. Therefore, the element holder 43 supported by these first beams 44, 44 is easily rotated about the C axis relative to the frame 41. In this way, by making the element holder 43 easily rotate about the C axis, it is not easy to hinder the detection vibration mode generated in the vibration element 6. Therefore, a decrease in the detection sensitivity of the vibration element 6 can be effectively suppressed.

[0056] In addition, in the first beam 44 on the positive side of the A axis and the first beam 44 on the negative side of the A axis with respect to the center O, the length L1 may be slightly different. In this case, however, the average value of the two may be set as the length L1. Similarly, in the first beam 44 on the positive side of the A axis and the first beam 44 on the negative side of the A axis with respect to the center O, the width W1 may be slightly different. In this case, however, the average value of the two may be set as the width W1.

[0057] Hereinafter, the above effects will be demonstrated based on the Figure 9 simulation results shown. Figure 9 is a graph showing the relationship between W1 2 / L1 and the sensitivity ratio (%). In this graph, W1 of each of the models 01 to 36 shown in Table 1 below is plotted 2The relationship between / L1 and the sensitivity ratio (%), and further shows the quadratic curve approximated by the least squares method. In addition, as can be seen from Table 1, the length L1, the width W1, and the length L2 of the component cage 43 in the direction along the A axis of each of the models 01 to 36 are different from each other. In addition, the length L1 is changed in the range of 150 μm to 700 μm, the width W1 is changed in the range of 50 μm to 200 μm, and the length L2 is changed in the range of 400 μm to 600 μm. In addition, the vertical axis in this figure, that is, the "sensitivity ratio", refers to the ratio of the detection sensitivity of the angular velocity ωc of the vibration element 6 in the structure in which the vibration element 6 is mounted on the TAB substrate via the inner lead as described in Patent Document 2 to the detection sensitivity of the vibration element 6 in the present embodiment. The higher the sensitivity ratio, the higher the sensitivity.

[0058] [Table 1]

[0059] L1 (um) W1 (um) L2 (um) <![CDATA[W1 2 / L1]]> Sensitivity ratio Model 01 150 50 400 16.67 83.6 Model 02 250 50 400 10.00 90.0 Model 03 300 50 400 8.33 91.9 Model 04 500 50 400 5.00 95.9 Model 05 700 50 400 3.57 97.5 Model 06 300 100 400 33.33 77.5 Model 07 500 100 400 20.00 85.6 Model 08 300 150 400 75.00 61.9 Model 09 500 150 400 45.00 72.0 Model 10 700 150 400 32.14 74.4 Model 11 150 100 400 66.67 68.3 Model 12 650 100 400 15.38 88.7 Model 13 400 200 400 100.00 56.1 Model 14 300 50 500 8.33 91.3 Model 15 500 50 500 5.00 95.7 Model 16 700 50 500 3.57 97.7 Model 17 300 100 500 33.33 77.3 Model 18 500 100 500 20.00 85.8 . Model 19 700 100 500 14.29 91.1 Model 20 300 150 500 75.00 62.2 Model 21 500 150 500 45.00 72.0 Model 22 700 150 500 32.14 80.9 Model 23 150 100 500 66.67 65.9 Model 24 150 50 500 16.67 82.8 Model 25 650 100 500 15.38 89.0 Model 26 400 200 500 100.00 57.0 Model 27 300 50 600 8.33 91.2 Model 28 500 50 600 5.00 95.7 Model 29 700 50 600 3.57 98.1 Model 30 150 100 600 66.67 66.5 Model 31 300 100 600 33.33 77.8 Model 32 500 100 600 20.00 86.4 Model 33 700 100 600 14.29 92.3 Model 34 650 100 600 15.38 91.0 Model 35 500 150 600 45.00 73.4 Model 36 300 150 600 75.00 63.1

[0060] As Figure 9 shown in the graph of, it can be seen that if the relationship of W1 2 / L1 < 30 is satisfied, the sensitivity ratio is approximately 80% or more, and the detection sensitivity of the vibration element 6 can be maintained high enough. In addition, if the relationship of W1 2 / L1 < 12.5 is satisfied, the sensitivity ratio is 90% or more, and it can be seen that the detection sensitivity of the vibration element 6 can be maintained higher. From such simulation results, it can be seen that the above-mentioned effect of "effectively suppressing the decrease in the detection sensitivity of the vibration element 6" can be obtained.

[0061] Here, if only the sensitivity is observed, compared with the structure in which the vibration element 6 is supported on the support member 4 as in the present embodiment, the structure in which the vibration element 6 is mounted on the TAB substrate via the inner lead as in the prior art is more likely to exhibit high sensitivity. However, in the structure in which the vibration element 6 is mounted on the TAB substrate via the inner lead, there are problems such as large processing deviations, and correspondingly, it is easy to generate unnecessary vibrations, or large processing deviations, and it is difficult to set conditions for reducing unnecessary vibrations. That is, although the structure in which the vibration element 6 is mounted on the TAB substrate via the inner lead can exhibit high detection sensitivity, there are problems such as large deviations in detection sensitivity and low yield rate.

[0062] In contrast, in a structure where the vibration element 6 is supported on the support member 4 as in the present embodiment, it is difficult to achieve the same detection sensitivity as that of a structure in which the vibration element 6 is mounted on a TAB substrate via an inner lead. However, since the support member 4 is formed of a quartz substrate, the support member 4 can be processed with high precision by etching, and the processing deviation is extremely small. In addition, since the processing deviation is small, the condition setting for reducing unnecessary vibrations becomes correspondingly easy. That is, in a structure where the vibration element 6 is supported on the support member 4 as in the present embodiment, although it is difficult to achieve high detection sensitivity, it has the advantages of small deviation in detection sensitivity and high yield rate.

[0063] Therefore, in the present embodiment, in order to utilize this advantage and achieve a detection sensitivity equal to or higher than that of a structure in which the vibration element 6 is mounted on a TAB substrate via an inner lead, as described above, the relationship of W1 2 / L1 < 30 is satisfied, and preferably the relationship of W1 2 / L1 < 12.5 is satisfied. Thereby, the vibration device 1 can achieve high detection sensitivity and can exhibit an extremely excellent effect of small deviation in detection sensitivity and high yield rate.

[0064] In addition, when viewed from above in the direction along the C axis, the element holder 43 of the support member 4 has the same shape as the element base 70 of the vibration element 6. In addition, in Figure 2 for the sake of easy explanation, the element holder 43 is illustrated as being slightly larger than the element base 70. Furthermore, when viewed from above in the direction along the C axis, the outer edges of the element holder 43 and the element base 70 overlap each other over the entire circumference. In this way, by making the element holder 43 and the element base 70 have the same shape, sufficient space for arranging six bonding members B2 on the element holder 43 can be ensured, and the element holder 43 can be reduced. Moreover, the lengths L1 of the first beams 44, 44 can be made longer corresponding to the reduction amount of the element holder 43, thereby improving the detection sensitivity of the vibration element 6. In addition, "the element holder 43 and the element base 70 have the same shape" means that in addition to the case where the shapes are exactly the same, it also includes cases where there are slight errors in the shapes due to manufacturing errors or manufacturing limitations.

[0065] However, the shape of the element holder 43 is not particularly limited, and it can be smaller than the element base 70 or larger than the element base 70. In addition, the top view shape can be the same as that of the element base 70 (i.e., it can be a similar shape) or different.

[0066] As described above, the vibration device 1 has been explained. As described above, such a vibration device 1 includes: a vibration element 6 that detects vibration based on a physical quantity, i.e., an angular velocity ωc, about a detection axis; a base 21; and a support 4 that supports the vibration element 6 with respect to the base 21. Further, when viewed from above in the thickness direction of the support 4, i.e., along the C axis, the support 4 has: a frame-shaped frame 41; a base 42 disposed outside the frame 41 and fixed to the base 21; an element holder 43 disposed inside the frame 41 and holding the vibration element 6; a pair of first beams 44, 44 extending from the element holder 43 to both sides in the direction along the A axis as the first direction and connecting the element holder 43 and the frame 41; and a pair of second beams 45, 45 extending from the frame 41 to both sides in the direction along the B axis as the second direction different from the direction along the A axis and connecting the frame 41 and the base 42. And, when viewed from above in the direction along the C axis, when the length of the first beam 44 in the direction along the A axis is set to L1 (μm) and the width W of the first beam 44 in the direction along the B axis perpendicular to the direction along the A axis is set to W1 (μm), it satisfies W1 2 / L1 < 30. By adopting such a structure, the vibration device 1 can exhibit high detection sensitivity and can achieve excellent effects such as small deviation in detection sensitivity and high yield rate.

[0067] Further, as described above, the vibration device 1 satisfies W1 2 / L1 < 12.5. By satisfying such a relationship, the vibration device 1 can exhibit even higher detection sensitivity and can achieve even more excellent effects such as small deviation in detection sensitivity and high yield rate.

[0068] Further, as described above, when three mutually perpendicular axes are set as the A axis, the B axis, and the C axis, the thickness direction of the support 4 is along the C axis, and the vibration element 6 has: an element base 70 fixed to the element holder 43; a pair of detection arms 71, 72 extending from the element base 70 along the B axis; a pair of connection arms 73, 74 extending from the element base 70 along the A axis; a pair of drive arms 75, 76 extending from the end of one connection arm 73 along the B axis; and a pair of drive arms 77, 78 extending from the end of the other connection arm 74 along the B axis. By adopting such a structure, a vibration element 6 with excellent vibration balance and high angular velocity detection characteristics can be obtained.

[0069] In addition, as described above, the first direction in which the first beams 44, 44 extend is along the A axis, and the second direction in which the second beams 45, 45 extend is along the B axis. Thus, the extending directions of the first beams 44, 44 are perpendicular to the extending directions of the second beams 45, 45, and stress can be more effectively absorbed and alleviated by the support member 4. In addition, by making the first beams 44, 44 extend along the A axis, which is the same direction as the extending direction of the connecting arms 73, 74, it is possible to easily ensure the same length L1 as that of the connecting arms 73, 74.

[0070] In addition, as described above, when viewed from above in the direction along the C axis, the element cage 43 and the element base 70 have the same shape. Thus, sufficient space required for arranging six engaging members B2 on the element cage 43 can be ensured, and the element cage 43 can be reduced. Moreover, the length L1 of the first beams 44, 44 can be increased corresponding to the reducible amount of the element cage 43, thereby improving the detection sensitivity of the vibrating element 6.

[0071] <Second Embodiment>

[0072] Figure 10 is a top view of the vibrating device according to the second embodiment.

[0073] This embodiment is the same as the first embodiment described above except that the orientation of the vibrating element 6 and the structure of the support member 4 are different. In addition, in the following description, for this embodiment, the differences from the above embodiment will be mainly described, and the description of the same matters will be omitted. In addition, in Figure 10 structures identical to those of the above embodiment are denoted by the same reference numerals.

[0074] As Figure 10 shown, in the vibrating device 1 of this embodiment, the vibrating element 6 is fixed to the support member 4 in a posture rotated 90 degrees about the C axis with respect to the first embodiment described above.

[0075] In addition, in the support member 4, a pair of first beams 44, 44 are located on both sides of the element cage 43 in the direction along the B axis, and connect the element cage 43 and the frame 41 in such a manner as to support the element cage 43 at both ends. In addition, the pair of first beams 44, 44 are respectively arranged in a straight line along the imaginary straight line Lb. On the other hand, a pair of second beams 45, 45 are located on both sides of the frame 41 in the direction along the A axis, and connect the frame 41 and the base 42 in such a manner as to support the frame 41 at both ends. In addition, the pair of second beams 45, 45 are respectively arranged in a straight line along the imaginary straight line La. According to such a structure, compared with the first embodiment described above, since the connecting portions of the second beams 45, 45 connected to the base 42 are close to the internal terminals 241, the wiring length of the wiring pattern arranged on the support member 4 can be shortened.

[0076] With such a second embodiment, the same effects as those of the above-described first embodiment can also be achieved.

[0077] <Third Embodiment>

[0078] Figure 11 It is a top view of the support member included in the vibration device of the third embodiment.

[0079] This embodiment is the same as the above-described first embodiment except for the structure of the support member 4. In the following description, regarding this embodiment, the description will focus on the differences from the above-described embodiments, and the description of the same matters will be omitted. In addition, in Figure 11 structures identical to those of the above-described embodiments are denoted by the same reference numerals.

[0080] As Figure 11 shown, in addition to the structure of the support member 4 of the above-described first embodiment, the support member 4 of this embodiment further includes a pair of third beams 46, 46 that extend from the frame 41 to both sides in the direction along the A axis and connect the frame 41 and the base 42. The pair of third beams 46, 46 are located on both sides of the frame 41 in the direction along the A axis and connect the frame 41 and the base 42 in such a manner as to support the frame 41 at both ends. That is, in the support member 4 of this embodiment, the frame 41 is configured to be supported from its four directions by the pair of second beams 45, 45 and the pair of third beams 46, 46. Thereby, the mechanical strength of the support member 4 is increased.

[0081] In particular, the pair of third beams 46, 46 are respectively arranged in a straight line along the imaginary straight line La. That is, the pair of third beams 46, 46 and the pair of first beams 44, 44 are arranged in a straight line. Therefore, the frame 41 can be supported more balancedly from its four directions. In addition, if the width W2 of the third beams 46, 46 is made too large, it may cause a decrease in the sensitivity of the vibration element 6. Therefore, although there is no particular limitation on the width W2 of the third beams 46, 46, it is preferably equal to or less than the width W1 of the first beams 44, 44.

[0082] As described above, in the vibration device 1 of this embodiment, the support member 4 includes a pair of third beams 46, 46 that extend from the frame 41 to both sides in the direction along the A axis as the first direction and connect the frame 41 and the base 42, and the pair of third beams 46, 46 and the pair of first beams 44, 44 are arranged in a straight line. Thereby, the frame 41 is supported from its four directions by the pair of second beams 45, 45 and the pair of third beams 46, 46. Therefore, the mechanical strength of the support member 4 is increased.

[0083] With such a third embodiment, the same effects as those of the above-described first embodiment can also be achieved.

[0084] As described above, the vibration device of the present invention has been described based on the illustrated embodiments. However, the present invention is not limited thereto, and the structure of each part can be replaced with any structure having the same function. In addition, any other structure can be added to the present invention. Moreover, the embodiments can be appropriately combined.

Claims

1. A vibration device, characterized in that, The vibration device includes: a vibration element including a base for detecting a physical quantity; and a support substrate for supporting the vibration element, when three mutually perpendicular axes are defined as the A-axis, B-axis, and C-axis, when viewed from above in the C-axis direction along the C-axis, the support substrate includes: a frame portion; a base fixing portion disposed outside the frame portion; an element mounting portion disposed inside the frame portion and mounting the vibration element; a pair of first beam portions extending from the element mounting portion toward the positive side and negative side of the A-axis, respectively, to connect the element mounting portion and the frame portion; and a pair of second beam portions extending from the frame portion toward the positive side and negative side of the B-axis, respectively, to connect the frame portion and the base fixing portion, when the length of the first beam portion in the A-axis direction along the A-axis is set as L1 and the width W of the first beam portion in the B-axis direction along the B-axis is set as W1, the following is satisfied: W1 2 / L1 < 30.

2. The vibration device according to claim 1, wherein The vibration device satisfies: W1 2 / L1 < 12.

5.

3. The vibration device according to claim 1 or 2, wherein in the top view, the base fixing portion is in a frame shape.

4. The vibration device according to claim 3, wherein the support substrate includes a pair of third beam portions, which extend from the frame portion toward the positive side and negative side of the A-axis, respectively, to connect the frame portion and the base fixing portion in the top view.

5. The vibration device according to claim 4, wherein in the top view, the pair of third beam portions and the pair of first beam portions are arranged in a straight line.

6. The vibration device according to claim 4, wherein when the width of the third beam portion in the B-axis direction is set as W2, the following is satisfied: W2≤W1.

7. The vibration device according to claim 1, wherein in the top view, the element mounting portion and the base have the same shape.

8. The vibration device according to claim 1, wherein the vibration device includes a base, and the base fixing portion is fixed to the base.

9. The vibration device according to claim 1, wherein the vibration element includes a pair of detection arms extending in the B-axis direction and performing bending vibration in the A-axis direction.

10. The vibration device according to claim 9, wherein the vibration element includes: a pair of connecting arms extending from the base toward the positive side and negative side of the A-axis, respectively; a driving arm extending in the B-axis direction from one of the pair of connecting arms; and a driving arm extending in the B-axis direction from the other of the pair of connecting arms.

11. An electronic device, characterized in that, including the vibration device according to any one of claims 1 to 10.

Images