Inertial sensor and vehicle

Abstract

The invention provides an inertial sensor and a vehicle, which can improve the detection accuracy of angular velocity. The inertial sensor includes: a package having a storage space; a sensor unit disposed in the housing space and including a first acceleration sensor element and a first angular velocity sensor element; a second angular velocity sensor element disposed in the housing space in an exposed state, the angular velocity sensor element having the same angular velocity detection axis as the first angular velocity sensor element; and a circuit element disposed in the housing space and electrically connected to the sensor unit and the second angular velocity sensor element.

Description

Technical Field

[0001] The present invention relates to an inertial sensor and a vehicle. Background Art

[0002] The inertial sensor module described in Patent Document 1 includes: a base substrate; a first sensor, a second sensor, and a third sensor mounted on the base substrate; and a cover covering the base substrate so as to cover the first, second, and third sensors. The first sensor is a three-axis angular velocity sensor comprising a first gyro sensor element for detecting angular velocity about the X-axis, a second gyro sensor element for detecting angular velocity about the Y-axis, and a third gyro sensor element for detecting angular velocity about the Z-axis. The third sensor is a three-axis acceleration sensor comprising a first acceleration sensor element for detecting acceleration in the X-axis direction, a second acceleration sensor element for detecting acceleration in the Y-axis direction, and a third acceleration sensor element for detecting acceleration in the Z-axis direction. Furthermore, the second sensor includes a vibration gyro sensor element for detecting angular velocity about the Z-axis, enabling higher-precision detection of angular velocity about the Z-axis compared to the third gyro sensor element described above.

[0003] Patent Document 1: Japanese Patent Application Laid-Open No. 2023-050622

[0004] To improve the angular velocity detection accuracy of a vibrating gyro sensor element, increasing the size of the vibrating gyro sensor element is effective. However, in the inertial sensor module of Patent Document 1, the vibrating gyro sensor element is housed in a package. Consequently, the vibrating gyro sensor element must be reduced in size to match the size of the package, making it difficult to further improve the angular velocity detection accuracy of the vibrating gyro sensor element. Summary of the Invention

[0005] The inertial sensor of the present invention comprises: a package having a storage space; a sensor unit arranged in the storage space and having a first acceleration sensor element and a first angular velocity sensor element; a second angular velocity sensor element arranged in an exposed state in the storage space, with an angular velocity detection axis identical to that of the first angular velocity sensor element; and a circuit element arranged in the storage space and electrically connected to the sensor unit and the second angular velocity sensor element.

[0006] The vehicle of the present invention includes the above-mentioned inertial sensor, wherein the angular velocity detection axis is along the yaw axis. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 This is a plan view showing the interior of the inertial sensor according to the first embodiment.

[0008] Figure 2 This is a cross-sectional view of the inertial sensor viewed from the negative side in the Y-axis direction.

[0009] Figure 3 This is a cross-sectional view of the inertial sensor before sealing, viewed from the negative side in the Y-axis direction.

[0010] Figure 4 It is a top view showing the interior of the sensor unit.

[0011] Figure 5 This is a cross-sectional view of the sensor unit as viewed from the negative side in the Y-axis direction.

[0012] Figure 6 This is a cross-sectional view of the triaxial angular velocity sensor as viewed from the negative side in the X-axis direction.

[0013] Figure 7 This is a cross-sectional view of the triaxial acceleration sensor as viewed from the negative side in the X-axis direction.

[0014] Figure 8 This is a top view of the angular velocity sensor element.

[0015] Figure 9 Schematic diagram showing a driving state of the angular velocity sensor.

[0016] Figure 10 Schematic diagram showing a driving state of the angular velocity sensor.

[0017] Figure 11 It is a plan view showing the dimensions of the angular velocity sensor element, the sensor unit, and the circuit element.

[0018] Figure 12 is a block diagram showing the functions of circuit elements.

[0019] Figure 13 It shows Figure 1 sectional view of a modified example of the inertial sensor shown.

[0020] Figure 14 It shows Figure 1 sectional view of a modified example of the inertial sensor shown.

[0021] Figure 15 It shows Figure 1 sectional view of a modified example of the inertial sensor shown.

[0022] Figure 16 It shows Figure 1 sectional view of a modified example of the inertial sensor shown.

[0023] Figure 17 It shows Figure 1 sectional view of a modified example of the inertial sensor shown.

[0024] Figure 18 It shows Figure 1 sectional view of a modified example of the inertial sensor shown.

[0025] Figure 19 It is a schematic diagram showing a vehicle according to the second embodiment.

[0026] Description of labels

[0027] 1: Inertial sensor; 100: Vehicle; 2: Package; 21: Base; 211: Recess; 211a: First recess; 211b: Second recess; 211c: Third recess; 22: Cover; 221: Groove; 23: Seam ring; 3: Sensor unit; 30: Leads; 31: Substrate; 32: Three-axis angular velocity sensor; 320: Package; 321: Base; 322x: X-axis angular velocity sensor element; 322y: Y-axis angular velocity sensor element; 322z: Z-axis angular velocity sensor element; 323: Cover; 33: Three-axis acceleration sensor; 330: Package; 331: Base; 332x: X-axis acceleration sensor element; 332y: Y-axis acceleration sensor element; 332z: Z-axis acceleration sensor element; 333: Cover; 34: Circuit element; 341: Control circuit unit; 342: Interface circuit unit; 35 : Molded part; 4: Angular velocity sensor element; 40: Base; 41: Detection vibration arm; 42: Detection vibration arm; 43: Support arm; 44: Support arm; 45: Drive vibration arm; 46: Drive vibration arm; 47: Drive vibration arm; 48: Drive vibration arm; 5: Support substrate; 51: Substrate; 511: Opening; 52: Lead; 6: Circuit element; 61: Control circuit part; 62: Integration processing part; 63: Interface circuit part; Ax: Acceleration; Ay: Acceleration; Az: Acceleration; B1: Joint part; B2: Joint part; E1: First detection signal electrode; E2: First detection ground electrode; E3: Second detection signal electrode; E4: Second detection ground electrode; E5: Drive signal electrode; E6: Drive ground electrode; EL: Energy line; S: Storage space; ωx: angular velocity; ωy: angular velocity; ωz: angular velocity. DETAILED DESCRIPTION

[0028] Hereinafter, the inertial sensor and the vehicle of the present invention will be described in detail based on the embodiments shown in the accompanying drawings. Figure 12In the figures other than the above, three mutually perpendicular axes are shown as the X-axis, Y-axis, and Z-axis. Hereinafter, for ease of explanation, the direction parallel to the X-axis, which is the first axis, is also referred to as the "X-axis direction," the direction parallel to the Y-axis, which is the second axis, is also referred to as the "Y-axis direction," and the direction parallel to the Z-axis is also referred to as the "Z-axis direction." Furthermore, the side indicated by the arrow in the Z-axis direction is also referred to as "upper," and the opposite side is referred to as "lower."

[0029] <First embodiment>

[0030] Figure 1 This is a plan view showing the interior of the inertial sensor according to the first embodiment. Figure 2 This is a cross-sectional view of the inertial sensor viewed from the negative side in the Y-axis direction. Figure 3 This is a cross-sectional view of the inertial sensor before sealing, viewed from the negative side in the Y-axis direction. Figure 4 It is a top view showing the interior of the sensor unit. Figure 5 This is a cross-sectional view of the sensor unit as viewed from the negative side in the Y-axis direction. Figure 6 This is a cross-sectional view of the triaxial angular velocity sensor as viewed from the negative side in the X-axis direction. Figure 7 This is a cross-sectional view of the triaxial acceleration sensor as viewed from the negative side in the X-axis direction. Figure 8 This is a top view of the angular velocity sensor element. Figure 9 as well as Figure 10 Each of them is a schematic diagram showing a driving state of the angular velocity sensor. Figure 11 It is a plan view showing the dimensions of the angular velocity sensor element, the sensor unit, and the circuit element. Figure 12 is a block diagram showing the functions of circuit elements. Figures 13 to 18 They are shown respectively Figure 1 sectional view of a modified example of the inertial sensor shown.

[0031] Figure 1 as well as Figure 2 The inertial sensor 1 shown includes a package 2 , a sensor unit 3 housed in the package 2 , an angular velocity sensor element 4 serving as a second angular velocity sensor element, a support substrate 5 , and a circuit element 6 .

[0032] [Package 2]

[0033] First, the package 2 will be described. Figure 1 and Figure 2As shown, the package 2 comprises a cavity-shaped base 21 with a recess 211 opening in its upper surface, and a plate-shaped cover 22 joined to the upper surface of the base 21 via a seam ring 23, thereby sealing the opening of the recess 211. By blocking the recess 211 with the cover 22, an airtight storage space S is formed within the package 2. This storage space S houses the sensor unit 3, the angular velocity sensor element 4, the support substrate 5, and the circuit element 6. The storage space S is hermetically sealed and placed in a reduced-pressure state, preferably a state closer to a vacuum. This reduces viscous resistance within the storage space S, thereby improving the vibration characteristics of the angular velocity sensor element 4, which is disposed in a naked state within the storage space S. However, the atmosphere of the storage space S is not particularly limited.

[0034] like Figure 3 As shown, a groove 221 is formed on the back of the cover 22 before airtight sealing. The groove 221 is provided at the outer edge of the positive side of the cover 22 in the X-axis direction, and its groove width in the Y-axis direction is smaller than the Y-axis dimension of the storage space S. The groove 221 spans the storage space S and the seam ring 23 when viewed from above. After the cover 22 and the seam ring 23 are seam-welded, the portion of the groove 221 remains in an unwelded state. Thus, the inside and outside of the storage space S are connected via the groove 221. Then, after the storage space S is evacuated via the groove 221, the laser or other energy line EL is irradiated near the groove 221 of the cover 22 to melt it, thereby blocking the groove 221. Thus, the storage space S is airtightly sealed. However, the method for airtightly sealing the storage space S is not particularly limited.

[0035] Furthermore, the groove 221 is preferably separated from the angular velocity sensor element 4. This effectively prevents droplets from the cover 22 that scatter within the storage space S during irradiation with the energy line EL from adhering to the angular velocity sensor element 4 and thereby deteriorating the vibration characteristics of the angular velocity sensor element 4. In this embodiment, since the angular velocity sensor element 4 is positioned within the storage space S toward the negative side in the X-axis direction, the groove 221 is formed at the end portion on the positive side in the X-axis direction, that is, the end portion opposite the angular velocity sensor element 4.

[0036] The material constituting the base 21 is not particularly limited; for example, various ceramics such as alumina can be used. The material constituting the lid 22 is also not particularly limited; it can be a member having a linear expansion coefficient similar to that of the material constituting the base 21. For example, if the material constituting the base 21 is ceramic, an alloy such as Kovar is preferably used.

[0037] In addition, if Figure 1 as well as Figure 2As shown, the recess 211 includes a first recess 211a, which opens on the top surface of the base 21; a second recess 211b, which opens on the bottom surface of the first recess 211a and has a smaller opening area than the first recess 211a; and a third recess 211c, which opens on the bottom surface of the second recess 211b and has a smaller opening area than the second recess 211b. Furthermore, the angular velocity sensor element 4 is mounted on the bottom surface of the first recess 211a via the support substrate 5, while the sensor unit 3 and the circuit element 6 are mounted on the bottom surface of the third recess 211c, aligned in the X-axis direction. Furthermore, the sensor unit 3 and the angular velocity sensor element 4 are electrically connected to the circuit element 6 via terminals and internal wiring (not shown) formed on the base 21.

[0038] [Sensor unit 3]

[0039] Next, the sensor unit 3 is described. The sensor unit 3 is a composite sensor unit that detects triaxial angular velocity and triaxial acceleration. Figure 1 as well as Figure 2 As shown, it is installed on the bottom surface of the third recess 211c.

[0040] like Figure 4 as well as Figure 5 As shown, the sensor unit 3 includes a substrate 31 with leads 30 mounted thereon; a triaxial angular velocity sensor 32, a triaxial acceleration sensor 33, and a circuit element 34 mounted on the upper surface of the substrate 31; and a molded member 35 formed by molding the triaxial angular velocity sensor 32, the triaxial acceleration sensor 33, and the circuit element 34 with the distal ends of the leads 30 exposed as terminals. The surface where the terminals are exposed is hereinafter referred to as the "terminal surface."

[0041] However, the structure of the sensor unit 3 is not particularly limited. For example, it may be a packaged structure housed in a ceramic package, etc., instead of a molded structure in which the three-axis angular velocity sensor 32, the three-axis acceleration sensor 33, and the circuit element 34 are molded and sealed by the molding component 35.

[0042] -Three-axis angular velocity sensor 32-

[0043] The triaxial angular velocity sensor 32 can detect the angular velocity ωx about the X axis, the angular velocity ωy about the Y axis, and the angular velocity ωz about the Z axis. The triaxial angular velocity sensor 32 is a silicon MEMS (Micro Electro Mechanical Systems), which allows for miniaturization of the triaxial angular velocity sensor 32.

[0044] In addition, if Figure 6As shown, the three-axis angular velocity sensor 32 includes a package 320 and an X-axis angular velocity sensor element 322x, a Y-axis angular velocity sensor element 322y, and a Z-axis angular velocity sensor element 322z, serving as first angular velocity sensor elements, housed in the package 320. The package 320 also includes a base 321 having a recessed portion on its top surface, with the sensor elements 322x, 322y, and 322z arranged to overlap the recessed portion; and a cover 323 bonded to the top surface of the base 321 to house the sensor elements 322x, 322y, and 322z between the base 321 and the cover.

[0045] Such a triaxial angular velocity sensor 32 can be formed, for example, by forming a base 321 from one silicon layer (handling layer) of an SOI (silicon on insulator) substrate, forming sensor elements 322x, 322y, and 322z from the other silicon layer (device layer), and bonding a cover 323 formed from the silicon substrate to the base 321. With this structure, the triaxial angular velocity sensor 32 can be manufactured using a silicon semiconductor process.

[0046] Hereinafter, the X-axis angular velocity sensor element 322 x , the Y-axis angular velocity sensor element 322 y , and the Z-axis angular velocity sensor element 322 z will be briefly described.

[0047] The X-axis angular velocity sensor element 322x includes a fixed comb electrode fixed to the base 321; a movable comb electrode meshing with the fixed comb electrode and capable of displacement relative to the base 321 in both the Y-axis and Z-axis directions; and a driving comb electrode for vibrating the movable comb electrode in the Y-axis direction. Furthermore, when an angular velocity ωx about the X-axis is applied to the X-axis angular velocity sensor element 322x while the movable comb electrode is vibrating in the Y-axis direction by energizing the driving comb electrode (a driven vibration state), the Coriolis force induces detection vibration in the Z-axis direction in the movable comb electrode. The capacitance between the fixed and movable comb electrodes changes in response to this detection vibration. This capacitance change can then be derived as an output signal, and the angular velocity ωx can be detected based on this output signal. However, the structure of the X-axis angular velocity sensor element 322x is not particularly limited as long as it can detect the angular velocity ωx.

[0048] The Y-axis angular velocity sensor element 322y includes a fixed comb electrode fixed to the base 321; a movable comb electrode meshing with the fixed comb electrode and capable of displacement relative to the base 321 in both the X-axis and Z-axis directions; and a driving comb electrode for vibrating the movable comb electrode in the X-axis direction. Furthermore, when an angular velocity ωy about the Y-axis is applied to the Y-axis angular velocity sensor element 322y while the driving comb electrode is energized, causing the movable comb electrode to vibrate in the X-axis direction (a driven vibration state), the Coriolis force induces detection vibration in the Z-axis direction in the movable comb electrode. The capacitance between the fixed and movable comb electrodes changes in response to this detection vibration. This capacitance change can then be derived as an output signal, and the angular velocity ωy can be detected based on this output signal. However, the configuration of the Y-axis angular velocity sensor element 322y is not particularly limited as long as it can detect the angular velocity ωy.

[0049] The Z-axis angular velocity sensor element 322z includes a fixed comb electrode fixed to the base 321; a movable comb electrode meshing with the fixed comb electrode and capable of displacement relative to the base 321 in both the X-axis and Y-axis directions; and a driving comb electrode for vibrating the movable comb electrode in the X-axis direction. Furthermore, when an angular velocity ωz about the Z-axis is applied to the Z-axis angular velocity sensor element 322z while the driving comb electrode is energized, causing the movable comb electrode to vibrate in the X-axis direction (a driven vibration state), the Coriolis force induces detection vibration in the Y-axis direction in the movable comb electrode. The capacitance between the fixed and movable comb electrodes changes in response to this detection vibration. This capacitance change can then be derived as an output signal, and the angular velocity ωz can be detected based on this output signal. However, the structure of the Z-axis angular velocity sensor element 322z is not particularly limited as long as it can detect the angular velocity ωz.

[0050] The three-axis angular velocity sensor 32 has been described above, but the structure of the three-axis angular velocity sensor 32 is not particularly limited. For example, the base 321 and the cover 323 may be formed of materials other than silicon, such as glass. In addition, in the illustrated structure, the sensor elements 322x, 322y, and 322z are arranged along the Y-axis direction, but their arrangement is not particularly limited. In addition, the package 320 may be divided for each sensor element 322x, 322y, and 322z. In this case, the sensor elements 322x, 322y, and 322z may be arranged to overlap in the Z-axis direction. In addition, two or more sensor elements selected from the sensor elements 322x, 322y, and 322z may be integrally formed into one sensor element. In other words, a structure may be provided in which two or more of the angular velocities ωx, ωy, and ωz can be detected by one sensor element.

[0051] Furthermore, the angular velocity sensor is not limited to the three-axis angular velocity sensor 32. As long as the Z-axis angular velocity sensor element 322z is included, the angular velocity detection axis of the angular velocity sensor may be two or one. That is, the angular velocity sensor may be a two-axis angular velocity sensor with an angular velocity detection axis for either the X-axis or Y-axis and an angular velocity detection axis for the Z-axis, or a single-axis angular velocity sensor with a single Z-axis.

[0052] -Triaxial acceleration sensor 33-

[0053] The triaxial acceleration sensor 33 can detect acceleration Ax in the X-axis direction, acceleration Ay in the Y-axis direction, and acceleration Az in the Z-axis direction. Like the triaxial angular velocity sensor 32 described above, the triaxial acceleration sensor 33 is a silicon MEMS. Therefore, the triaxial acceleration sensor 33 can be miniaturized.

[0054] In addition, if Figure 7 As shown, the triaxial acceleration sensor 33 includes a package 330 and an X-axis acceleration sensor element 332x, a Y-axis acceleration sensor element 332y, and a Z-axis acceleration sensor element 332z, serving as first acceleration sensor elements, housed in the package 330. The package 330 also includes a base 331 having a recessed portion open in its upper surface, with the sensor elements 332x, 332y, and 332z arranged to overlap the recessed portion; and a cover 333 bonded to the upper surface of the base 331 to house the sensor elements 332x, 332y, and 332z between the base 331 and the cover.

[0055] Such a triaxial acceleration sensor 33 can be formed, for example, by forming a base 331 from one silicon layer (handling layer) of an SOI substrate, forming sensor elements 332x, 332y, and 332z from the other silicon layer (device layer), and bonding a cover 333 formed from a silicon substrate to the base 331. With this structure, the triaxial acceleration sensor 33 can be manufactured using a silicon semiconductor process.

[0056] Hereinafter, the X-axis acceleration sensor element 332 x , the Y-axis acceleration sensor element 332 y , and the Z-axis acceleration sensor element 332 z will be briefly described.

[0057] The X-axis acceleration sensor element 332x includes a fixed comb electrode fixed to the base 331 and a movable comb electrode configured to engage with the fixed comb electrode and capable of displacement in the X-axis direction relative to the base 331. Furthermore, when an acceleration Ax in the X-axis direction is applied to the X-axis acceleration sensor element 332x, the movable comb electrode displaces in the X-axis direction, and the electrostatic capacitance between the fixed comb electrode and the movable comb electrode changes in accordance with this displacement. Therefore, this change in electrostatic capacitance can be derived as an output signal, and acceleration Ax can be detected based on this output signal. However, the structure of the X-axis acceleration sensor element 332x is not particularly limited as long as it can detect acceleration Ax.

[0058] The Y-axis acceleration sensor element 332y includes a fixed comb electrode fixed to the base 331 and a movable comb electrode configured to engage with the fixed comb electrode and capable of displacement in the Y-axis direction relative to the base 331. Furthermore, when an acceleration Ay in the Y-axis direction is applied to the Y-axis acceleration sensor element 332y, the movable comb electrode displaces in the Y-axis direction, and the electrostatic capacitance between the fixed comb electrode and the movable comb electrode changes in accordance with this displacement. Therefore, this change in electrostatic capacitance can be derived as an output signal, and acceleration Ay can be detected based on this output signal. However, the structure of the Y-axis acceleration sensor element 332y is not particularly limited as long as it can detect acceleration Ay.

[0059] The Z-axis acceleration sensor element 332z includes a fixed comb electrode fixed to the base 331 and a movable comb electrode configured to engage with the fixed comb electrode and capable of displacement in the Z-axis direction relative to the base 331. Furthermore, when an acceleration Az in the Z-axis direction is applied to the Z-axis acceleration sensor element 332z, the movable comb electrode displaces in the Z-axis direction, and the electrostatic capacitance between the fixed comb electrode and the movable comb electrode changes in accordance with this displacement. Therefore, this change in electrostatic capacitance can be derived as an output signal, and acceleration Az can be detected based on this output signal. However, the structure of the Z-axis acceleration sensor element 332z is not particularly limited as long as it can detect acceleration Az.

[0060] The above describes the three-axis acceleration sensor 33, but the structure of the three-axis acceleration sensor 33 is not particularly limited. For example, the base 331 and the cover 333 may be formed of materials other than silicon, such as glass. In addition, in the structure shown in the figure, the sensor elements 332x, 332y, and 332z are arranged along the Y-axis direction, but their arrangement is not particularly limited. In addition, the package 330 may be divided according to each sensor element 332x, 332y, and 332z. In this case, the sensor elements 332x, 332y, and 332z may be arranged to overlap in the Z-axis direction. In addition, two or more sensor elements selected from the sensor elements 332x, 332y, and 332z may be integrally formed into one sensor element. In other words, a structure may be adopted in which two or more of the accelerations Ax, Ay, and Az can be detected by one sensor element. In addition, the acceleration detection axis may be two axes or one axis, without being limited to the three-axis acceleration sensor 33.

[0061] -Circuit Component 34-

[0062] The circuit element 34 is electrically connected to the three-axis angular velocity sensor 32 and the three-axis acceleration sensor 33 via the substrate 31. The circuit element 34 is, for example, an MCU (Micro Controller Unit) that centrally controls various components of the sensor unit 3. Figure 4 as well as Figure 5 As shown, the circuit element 34 includes a control circuit unit 341 that controls the driving of the triaxial angular velocity sensor 32 and the triaxial acceleration sensor 33 , and an interface circuit unit 342 that communicates with the circuit element 6 .

[0063] The control circuit unit 341 controls the driving of the three-axis angular velocity sensor 32, detecting angular velocity ωx based on the output signal of the X-axis angular velocity sensor element 322x, angular velocity ωy based on the output signal of the Y-axis angular velocity sensor element 322y, and angular velocity ωz based on the output signal of the Z-axis angular velocity sensor element 322z. Furthermore, the control circuit unit 341 controls the driving of the three-axis acceleration sensor 33, detecting acceleration Ax based on the output signal of the X-axis acceleration sensor element 332x, acceleration Ay based on the output signal of the Y-axis acceleration sensor element 332y, and acceleration Az based on the output signal of the Z-axis acceleration sensor element 332z.

[0064] The interface circuit unit 342 transmits and receives signals, accepts commands from the circuit element 6, and outputs the detected angular velocities ωx, ωy, ωz and accelerations Ax, Ay, and Az to the circuit element 6. The communication method is not particularly limited, but in this embodiment, SPI (Serial Peripheral Interface) communication is used. SPI communication is suitable for connecting multiple sensors and can output all signals related to the angular velocities ωx, ωy, ωz and accelerations Ax, Ay, and Az from a single pin. This allows for pin reduction in the sensor unit 3.

[0065] The sensor unit 3 has been described above. Figure 2 As shown, the sensor unit 3 is mounted face-down on the bottom surface of the third recess 211c with its terminals facing downward. By mounting the sensor unit 3 face-down in this manner, it can be connected to terminals (not shown) formed on the base 21 without wires, thereby miniaturizing the inertial sensor 1.

[0066] [Angular velocity sensor element 4]

[0067] Next, the angular velocity sensor element 4 will be described. Figure 1 as well as Figure 2 As shown, the angular velocity sensor element 4 is arranged above the circuit element 6 and overlaps with the circuit element 6 when viewed from above in the Z-axis direction. By arranging the angular velocity sensor element 4 and the circuit element 6 in this way, the planar expansion of the inertial sensor 1 can be suppressed, thereby achieving miniaturization of the inertial sensor 1. Furthermore, since the angular velocity sensor element 4 can be arranged in a larger space above the circuit element 6 and the sensor unit 3, the size of the angular velocity sensor element 4 can be easily increased.

[0068] The angular velocity sensor element 4 is a quartz vibration element and can detect the angular velocity ωz around the Z axis. That is, the angular velocity detection axis of the angular velocity sensor element 4 is the Z axis. Figure 8As shown, this angular velocity sensor element 4 includes a quartz substrate integrally formed with a base portion 40 located in the center, a pair of detection vibration arms 41 and 42 extending from the base portion 40 in the X-axis direction, a pair of support arms 43 and 44 extending from the base portion 40 in the Y-axis direction, a pair of drive vibration arms 45 and 46 extending from the distal end of one support arm 43 in the X-axis direction, and a pair of drive vibration arms 47 and 48 extending from the distal end of the other support arm 44 in the X-axis direction. Furthermore, the angular velocity sensor element 4 is supported by a support substrate 5 at the base portion 40.

[0069] The angular velocity detection axis of angular velocity sensor element 4 and the angular velocity detection axis of Z-axis angular velocity sensor element 322z are both the Z-axis and are the same angular velocity detection axis. Here, "the same angular velocity detection axis" means that the angular error of the angular velocity detection axis of Z-axis angular velocity sensor element 322z relative to the angular velocity detection axis of angular velocity sensor element 4 is less than ±5 degrees.

[0070] In addition, the angular velocity sensor element 4 has: a first detection signal electrode E1, which is arranged on the two main surfaces of the detection vibration arm 41; a first detection ground electrode E2, which is arranged on the two side surfaces of the detection vibration arm 41; a second detection signal electrode E3, which is arranged on the two main surfaces of the detection vibration arm 42; a second detection ground electrode E4, which is arranged on the two side surfaces of the detection vibration arm 42; a driving signal electrode E5, which is arranged on the two main surfaces of the driving vibration arms 45, 46 and on the two side surfaces of the driving vibration arms 47, 48; and a driving ground electrode E6, which is arranged on the two side surfaces of the driving vibration arms 45, 46 and on the two main surfaces of the driving vibration arms 47, 48.

[0071] The angular velocity sensor element 4 described above detects the angular velocity ωz in the following manner. When a driving signal is applied to the driving signal electrode E5, Figure 9 As shown in FIG. 1 , the driving vibration arms 45 and 46 and the driving vibration arms 47 and 48 perform bending vibrations in opposite phases in the Y-axis direction (hereinafter, this state is also referred to as the "driving vibration mode"). In this state, the vibrations of the driving vibration arms 45 and 46 and the vibrations of the driving vibration arms 47 and 48 are canceled out, and the detection vibration arms 41 and 42 do not substantially vibrate. When an angular velocity ωz is applied to the angular velocity sensor element 4 in the state of being driven in the driving vibration mode, as shown in FIG. Figure 10 As shown, the Coriolis force acts on the driving vibration arms 45, 46, 47, and 48 to excite bending vibration in the X-axis direction, and the detection vibration arms 41 and 42 perform bending vibration in the Y-axis direction in response to the bending vibration (hereinafter, this state is also referred to as "detection vibration mode").

[0072] The charge generated in the detection vibration arm 41 by this detection vibration mode is derived from the first detection signal electrode E1 as a first detection signal, and the charge generated in the detection vibration arm 42 is derived from the second detection signal electrode E3 as a second detection signal. The angular velocity ωz is calculated based on the differential signal, or output signal, between these first and second detection signals. Furthermore, because the angular velocity sensor element 4 is constructed from a quartz resonator, it can detect the angular velocity ωz with higher accuracy than the Z-axis angular velocity sensor element 322z constructed from a silicon MEMS. One reason for this is that the frequency-temperature characteristics of a quartz resonator are superior to those of a silicon MEMS.

[0073] In particular, in this embodiment, when the bias error (output error at rest) of the output signal of angular velocity sensor element 4 is set to Bz1 [deg / second] and the bias error (output error at rest) of the output signal of Z-axis angular velocity sensor element 322z is set to Bz2 [deg / second], the relationship Bz1 < Bz2 is satisfied. Furthermore, the relationship Bz1 < 0.5Bz2 is preferably satisfied, and the relationship Bz1 < 0.3Bz2 is even more preferably satisfied. By satisfying this relationship, angular velocity sensor element 4 can detect angular velocity ωz with higher accuracy than Z-axis angular velocity sensor element 322z.

[0074] Furthermore, in the inertial sensor 1, the angular velocity sensor element 4 is exposed within the storage space S. That is, the angular velocity sensor element 4 is disposed in a naked state within the storage space S. Therefore, when compared with a package 2 of the same size, the size of the angular velocity sensor element 4 can be increased compared to a conventional structure in which the angular velocity sensor element 4 is housed within the package. The increased size of the angular velocity sensor element 4 results in a correspondingly larger output signal, improving the signal-to-noise ratio (S / N) and further enhancing the accuracy of angular velocity ωz detection. Furthermore, the increased size reduces the dimensional error of the quartz crystal vibration substrate, effectively suppressing the generation of spurious signals during the driven vibration state. Consequently, the offset error in the output signal of the angular velocity sensor element 4 can be further minimized. Consequently, the angular velocity sensor element 4 can detect angular velocity ωz with even higher accuracy.

[0075] In this embodiment, if Figure 11As shown, when the length of the angular velocity sensor element 4 in the X-axis direction is Lx1 and the lengths of the X-axis, Y-axis, and Z-axis angular velocity sensor elements 322x, 322y, and 322z in the X-axis direction are Lx2, Lx1>Lx2. Furthermore, if the lengths Lx2 differ among the X-axis, Y-axis, and Z-axis angular velocity sensor elements 322x, 322y, and 322z, the longest of these lengths is Lx2. Furthermore, if the lengths Lx3 differ among the X-axis, Y-axis, and Z-axis acceleration sensor elements 332x, 332y, and 332z in the X-axis direction are Lx3, Lx1>Lx3. Furthermore, if the lengths Lx3 differ among the X-axis, Y-axis, and Z-axis acceleration sensor elements 332x, 332y, and 332z, the longest of these lengths is Lx3. By satisfying the relationships Lx1>Lx2 and Lx1>Lx3 in this way, the size of the angular velocity sensor element 4 becomes sufficiently large. Therefore, the angular velocity sensor element 4 can further improve its detection accuracy of the angular velocity ωz. In particular, in this embodiment, when the length of the sensor unit 3 in the X-axis direction is Lx4, Lx1>Lx4. Satisfying this relationship allows the size of the angular velocity sensor element 4 to be further increased. Consequently, the angular velocity sensor element 4 can further improve its detection accuracy of the angular velocity ωz.

[0076] Furthermore, when the length of the angular velocity sensor element 4 in the Y-axis direction is Ly1 and the lengths of the X-axis, Y-axis, and Z-axis angular velocity sensor elements 322x, 322y, and 322z in the Y-axis direction are Ly2, Ly1 > Ly2. Furthermore, if the lengths Ly2 differ among the X-axis, Y-axis, and Z-axis angular velocity sensor elements 322x, 322y, and 322z, the longest of these lengths is Ly2. Furthermore, if the lengths Ly3 differ among the X-axis, Y-axis, and Z-axis acceleration sensor elements 332x, 332y, and 332z in the Y-axis direction are Ly3, Ly1 > Ly3. Furthermore, if the lengths Ly3 differ among the X-axis, Y-axis, and Z-axis acceleration sensor elements 332x, 332y, and 332z, the longest of these lengths is Ly3. By satisfying the relationships Ly1 > Ly2 and Ly1 > Ly3, the size of the angular velocity sensor element 4 becomes sufficiently large. Therefore, the detection accuracy of the angular velocity ωz by the angular velocity sensor element 4 can be further improved. In particular, in this embodiment, when the length of the sensor unit 3 in the Y-axis direction is Ly4, Ly1>Ly4. By satisfying this relationship, the size of the angular velocity sensor element 4 can be further increased. Therefore, the detection accuracy of the angular velocity ωz by the angular velocity sensor element 4 can be further improved.

[0077] Although the angular velocity sensor element 4 has been described above, there is no particular limitation on the arrangement and structure of the angular velocity sensor element 4. For example, a silicon MEMS type angular velocity sensor element may be used as the angular velocity sensor element 4.

[0078] [Support substrate 5]

[0079] Next, the support substrate 5 will be described. The support substrate 5 supports the angular velocity sensor element 4 and has a function of electrically connecting the angular velocity sensor element 4 to terminals (not shown) formed on the base 21. Figure 8 As shown, the support substrate 5 is fixed to the bottom surface of the first recess 211a. Furthermore, the support substrate 5 is located below the angular velocity sensor element 4 and supports the angular velocity sensor element 4 by being raised from below. Thus, by interposing the support substrate 5 between the base 21 and the angular velocity sensor element 4, stress is less likely to be applied to the angular velocity sensor element 4, thereby improving the angular velocity detection accuracy of the angular velocity sensor element 4.

[0080] The support substrate 5 is a substrate for TAB (Tape Automated Bonding) mounting, such as Figure 8 As shown, there is a substrate 51 and six leads 52 arranged on the substrate 51. In addition, the substrate 51 is frame-shaped when viewed from above in the Z-axis direction, and has an opening 511 on the inner side. Such a substrate 51 is composed of a film composed of an insulating resin such as polyimide. However, there is no particular limitation on the constituent material of the substrate 51. For example, it can also be composed of an insulating resin other than polyimide. In addition, the substrate 51 is in the shape of an elongated strip extending in the Y-axis direction, and is fixed to the bottom surface of the first recess 211a at both ends in the Y-axis direction by bonding components B1. Furthermore, each lead 52 is electrically connected to a terminal (not shown) formed on the base 21 via the bonding component B1.

[0081] The six leads 52 are bonding wires that support the angular velocity sensor element 4 and are conductive wiring patterns. In this embodiment, each lead 52 is made of a metal foil such as copper foil. This facilitates the formation of the leads 52. Furthermore, three of the six leads 52 are positioned on the positive side in the Y-axis direction relative to the center of the substrate 51, with their distal ends extending into the opening 511 of the substrate 51. The remaining three leads 52 are positioned on the negative side in the Y-axis direction relative to the center of the substrate 51, with their distal ends extending into the opening 511 of the substrate 51.

[0082] Each of these leads 52 bends midway in the Z-axis direction and tilts upward, with its distal end passing through the opening 511 and positioned above the substrate 51. Furthermore, the base 40 of the angular velocity sensor element 4 is fixed to the distal end of each lead 52 via a bonding member B2. Although not shown, each lead 52 is electrically connected to the corresponding electrodes E1 to E6 via the bonding member B2.

[0083] While the support substrate 5 has been described above, the structure of the support substrate 5 is not particularly limited. For example, the support substrate 5 can be constructed by etching a quartz plate to form a frame and a beam extending from the frame toward the center of the plate, and providing wiring patterns on the frame and beam. In this case, the angular velocity sensor element 4 is fixed to the support substrate 5 near the end of the beam via the bonding member B2.

[0084] [Circuit element 6]

[0085] like Figure 1 and Figure 2 As shown, the circuit element 6 is mounted on the bottom surface of the third recess 211c in parallel with the sensor unit 3. In addition, the circuit element 6 is electrically connected to the sensor unit 3 and the angular velocity sensor element 4 via the base 21. The circuit element 6 is, for example, an MCU (Micro Controller Unit) that controls all parts of the inertial sensor 1. Figure 12 As shown, such a circuit element 6 has: a control circuit unit 61, which controls the drive of the angular velocity sensor element 4; an integration processing unit 62, which corrects the angular error between the Z-axis angular velocity sensor element 322z and the detection axis of the angular velocity sensor element 4; and an interface circuit unit 63, which communicates with an external device.

[0086] The control circuit unit 61 controls the drive of the angular velocity sensor element 4 and detects the angular velocity ωz based on the output signal of the angular velocity sensor element 4. The alignment processing unit 62 corrects the output signal of the angular velocity sensor element 4 based on the angular error of the detection axis of the angular velocity sensor element 4 relative to the detection axis of the Z-axis angular velocity sensor element 322z. In other words, the output signal of the angular velocity sensor element 4 is calibrated so that the detection axis of the angular velocity sensor element 4 coincides with the detection axis of the Z-axis angular velocity sensor element 322z. This enables the angular velocity sensor element 4 to detect the angular velocity about an axis that coincides with the detection axis of the Z-axis angular velocity sensor element 322z.

[0087] The interface circuit unit 63 transmits and receives signals, accepting commands from external devices and outputting the angular velocities ωx, ωy, ωz and accelerations Ax, Ay, and Az detected by the sensor unit 3, and the angular velocity ωz detected by the angular velocity sensor element 4, to the external device. The communication method is not particularly limited, but in this embodiment, SPI (Serial Peripheral Interface) communication is used. SPI communication is suitable for connecting multiple sensors and can output all signals related to the angular velocities ωx, ωy, ωz and accelerations Ax, Ay, and Az from a single pin. This reduces the number of pins required for the inertial sensor 1.

[0088] Furthermore, in the inertial sensor 1, the Z-axis angular velocity sensor element 322z and the angular velocity sensor element 4 each detect angular velocity ωz. Furthermore, as previously described, the angular velocity sensor element 4 has higher detection accuracy for angular velocity ωz than the Z-axis angular velocity sensor element 322z. Therefore, instead of outputting the angular velocity ωz detected by the Z-axis angular velocity sensor element 322z to an external device, the interface circuit unit 63 may bundle the angular velocities ωx, ωy, and accelerations Ax, Ay, and Az detected by the sensor unit 3 with the angular velocity ωz detected by the angular velocity sensor element 4, totaling six signals, and output them to the external device. Alternatively, the interface circuit unit 63 may bundle the angular velocities ωx, ωy, and ωz detected by the sensor unit 3, accelerations Ax, Ay, and Az detected by the angular velocity sensor element 4, totaling seven signals, and output them to the external device. In this case, the user simply decides whether to use the angular velocity ωz detected by the Z-axis angular velocity sensor element 322z, the angular velocity ωz detected by the angular velocity sensor element 4, or both. Furthermore, because the inertial sensor 1 includes two sensors for detecting the angular velocity about the Z-axis—the angular velocity sensor element 4 and the Z-axis angular velocity sensor element 322z—even if one of the two sensors detecting the angular velocity about the Z-axis fails, the angular velocity about the Z-axis can still be detected using the other. This improves the robustness of the angular velocity detection about the Z-axis.

[0089] The inertial sensor 1 has been described above. As described above, this inertial sensor 1 includes a package 2 having a housing space S; a sensor unit 3 disposed in the housing space S and including X-axis, Y-axis, and Z-axis acceleration sensor elements 332x, 332y, and 332z as first acceleration sensor elements, and X-axis, Y-axis, and Z-axis angular velocity sensor elements 322x, 322y, and 322z as first angular velocity sensor elements; an angular velocity sensor element 4 as a second angular velocity sensor element, exposed in the housing space S and having the same angular velocity detection axis as the Z-axis angular velocity sensor element 322z; and a circuit element 6 disposed in the housing space S and electrically connected to the sensor unit 3 and the angular velocity sensor element 4. This configuration allows the angular velocity sensor element 4 to be exposed in the housing space S. Therefore, when compared with a package 2 of the same size, the size of the angular velocity sensor element 4 can be increased compared to a conventional configuration in which the angular velocity sensor element 4 is housed within the package. Therefore, the angular velocity sensor element 4 can detect the angular velocity ωz with higher accuracy.

[0090] Furthermore, as previously described, the angular velocity sensor element 4 is arranged so as to overlap at least one of the sensor unit 3 and the circuit element 6 when viewed from above along the Z-axis, which serves as the angular velocity detection axis. In this embodiment, the angular velocity sensor element 4 is arranged to overlap the circuit element 6. This configuration suppresses the planar expansion of the inertial sensor 1, enabling miniaturization of the inertial sensor 1. Furthermore, since the angular velocity sensor element 4 can be arranged in a relatively large space above the circuit element 6, the size of the angular velocity sensor element 4 can be easily increased.

[0091] As described above, the angular velocity sensor element 4 is supported by the package 2 via the support substrate 5. This structure reduces stress on the angular velocity sensor element 4, thereby improving the angular velocity detection accuracy of the angular velocity sensor element 4.

[0092] Furthermore, as described above, when the X-axis direction is defined as the first axis direction and the Y-axis direction is defined as the second axis direction, the length Lx1 of the angular velocity sensor element 4 in the X-axis direction is greater than the length Lx2 of the X-axis, Y-axis, and Z-axis angular velocity sensor elements 322x, 322y, and 322z in the X-axis direction. This configuration allows the size of the angular velocity sensor element 4 to be sufficiently large. Consequently, the accuracy of angular velocity ωz detection by the angular velocity sensor element 4 can be further improved.

[0093] Furthermore, as previously described, the length Ly1 of the angular velocity sensor element 4 in the Y-axis direction is greater than the length Ly2 of the X-axis, Y-axis, and Z-axis angular velocity sensor elements 322x, 322y, and 322z in the Y-axis direction. This structure allows the size of the angular velocity sensor element 4 to be sufficiently large. Consequently, the accuracy of angular velocity ωz detection by the angular velocity sensor element 4 can be further improved.

[0094] Furthermore, as previously mentioned, the length Lx1 of the angular velocity sensor element 4 in the X-axis direction is greater than the length Lx3 of the X-axis, Y-axis, and Z-axis acceleration sensor elements 332x, 332y, and 332z in the X-axis direction. This structure allows the size of the angular velocity sensor element 4 to be sufficiently large. Consequently, the accuracy of angular velocity ωz detection by the angular velocity sensor element 4 can be further improved.

[0095] Furthermore, as previously described, the length Ly1 of the angular velocity sensor element 4 in the Y-axis direction is greater than the length Ly3 of the X-axis, Y-axis, and Z-axis acceleration sensor elements 332x, 332y, and 332z in the Y-axis direction. This configuration allows the size of the angular velocity sensor element 4 to be sufficiently large. Consequently, the accuracy of angular velocity ωz detection by the angular velocity sensor element 4 can be further improved.

[0096] Furthermore, as described above, the pressure in the accommodation space S is reduced. With such a configuration, the viscous resistance in the accommodation space S is reduced, and the vibration characteristics of the angular velocity sensor element 4 are improved.

[0097] As described above, the bias error Bz1 of the output signal of angular velocity sensor element 4 is smaller than the bias error Bz2 of the output signal of Z-axis angular velocity sensor element 322z. With this configuration, angular velocity sensor element 4 can detect angular velocity ωz with higher accuracy than Z-axis angular velocity sensor element 322z.

[0098] As described above, circuit element 6 includes integration processing unit 62 for correcting the angular error between Z-axis angular velocity sensor element 322z and the angular velocity detection axis of angular velocity sensor element 4. With this configuration, angular velocity sensor element 4 can detect the angular velocity about an axis that coincides with the detection axis of Z-axis angular velocity sensor element 322z.

[0099] As described above, the sensor unit 3 includes three first acceleration sensor elements, namely, the X-axis, Y-axis, and Z-axis acceleration sensor elements 332x, 332y, and 332z, arranged with their acceleration detection axes perpendicular to one another; and three first angular velocity sensor elements, namely, the X-axis, Y-axis, and Z-axis angular velocity sensor elements 322x, 322y, and 322z, arranged with their angular velocity detection axes perpendicular to one another. Furthermore, the angular velocity detection axis of the angular velocity sensor element 4 is the same as the angular velocity detection axis of any one of the X-axis, Y-axis, and Z-axis angular velocity sensor elements 322x, 322y, and 322z, or, in this embodiment, the angular velocity detection axis of the Z-axis angular velocity sensor element 322z. This configuration enables detection of inertia along a total of six axes. Among these, the angular velocity about the Z-axis can be detected with particularly high accuracy, resulting in a highly convenient inertial sensor 1.

[0100] The inertial sensor 1 according to the present embodiment has been described above. However, the structure of the inertial sensor 1 is not particularly limited.

[0101] For example, Figure 13 As shown, the sensor unit 3 may be mounted face-up on the bottom surface of the third recess 211c with its terminals facing upward. Although not shown, in this case, the sensor unit 3 is electrically connected to the terminals disposed on the base 21 via bonding wires.

[0102] In addition, for example, Figure 14 As shown in FIG. 1 , the sensor unit 3 can also be mounted face-down on the upper surface of the circuit element 6 with the terminal surface facing downward. According to such a structure, the size of the circuit element 6 can be increased compared to the present embodiment. Therefore, the circuit element 6 can be made high-performance and multifunctional. Figure 15 As shown, relative to Figure 14 , the sensor unit 3 may be turned upside down and mounted face-up on the upper surface of the circuit element 6 with the terminal surface facing upward.

[0103] In addition, for example, Figure 16 As shown in FIG. 1 , the sensor unit 3 may be mounted face-down on the upper surface of the circuit element 6 with the terminal surface facing downward, and the angular velocity sensor element 4 may be arranged on the upper side of the sensor unit 3. According to such a structure, since the angular velocity sensor element 4, the support substrate 5, the sensor unit 3, and the circuit element 6 can be arranged in an overlapping manner, the planar expansion of the inertial sensor 1 can be suppressed compared to the present embodiment, thereby achieving miniaturization of the inertial sensor 1. In addition, as shown in FIG. Figure 17 As shown, it can also be compared with Figure 16 The sensor unit 3 is turned upside down and mounted face up on the upper surface of the circuit element 6 with the terminal surface facing upward.

[0104] In addition, for example, Figure 18 As shown, the circuit element 6 may be mounted on the upper surface of the sensor unit 3, and the angular velocity sensor element 4 may be arranged above the circuit element 6. With this structure, the angular velocity sensor element 4, the support substrate 5, the sensor unit 3, and the circuit element 6 can be arranged in an overlapping manner. Therefore, compared to the present embodiment, the planar expansion of the inertial sensor 1 can be suppressed, thereby achieving miniaturization of the inertial sensor 1.

[0105] <Second embodiment>

[0106] Figure 19 It is a schematic diagram showing a vehicle according to the second embodiment.

[0107] like Figure 19 As shown, the vehicle 100 of this embodiment is an automobile. However, the vehicle 100 is not limited to an automobile, and may be, for example, an agricultural machine such as a tractor or a construction machine such as a forklift.

[0108] Vehicle 100 is also equipped with an inertial sensor 1. The inertial sensor 1 is oriented with its X-axis oriented in the front-to-back direction of the vehicle 100, its Y-axis oriented in the left-to-right direction of the vehicle 100, and its Z-axis oriented in the up-to-down direction of the vehicle 100. Therefore, the X-axis of the inertial sensor 1 coincides with the roll axis of the vehicle 100, the Y-axis of the inertial sensor 1 coincides with the pitch axis of the vehicle 100, and the Z-axis of the inertial sensor 1 coincides with the yaw axis of the vehicle 100. Therefore, the attitude of the vehicle 100 is represented by the roll angle around the X-axis, the pitch angle around the Y-axis, and the yaw angle around the Z-axis. The roll angle corresponds to the left-to-right tilt of the vehicle 100, the pitch angle corresponds to the front-to-back tilt of the vehicle 100, and the yaw angle corresponds to the shift in the direction of movement or the orientation of the vehicle 100.

[0109] For example, in various vehicle 100 controls, such as autonomous driving, the most important of the roll, pitch, and yaw angles is the yaw angle, which corresponds to changes in the vehicle 100's direction of movement or orientation. This is because the yaw angle detection error (the difference between the actual value and the measured value) is directly related to the vehicle 100's heading error (the difference between the actual heading and the measured heading). In contrast, the roll and pitch angle errors are not directly related to the vehicle 100's heading error. Furthermore, to reduce the vehicle 100's heading error, improving the yaw angle detection accuracy is more effective. While it is desirable to use a sensor capable of detecting all roll, pitch, and yaw angles with high accuracy, this results in increased sensor size and cost. In this regard, the inertial sensor 1, which can detect the yaw angle with particularly high accuracy using the angular velocity sensor element 4 and the roll and pitch angles with sufficient accuracy using the sensor unit 3, can effectively contribute to reducing the error in the direction of travel of the vehicle 100 while achieving device miniaturization and cost reduction. Therefore, the inertial sensor 1 has excellent compatibility with the vehicle 100 and high affinity.

[0110] As described above, the vehicle 100 includes the inertial sensor 1 , and the Z axis, which is the angular velocity detection axis, is along the yaw axis.

[0111] According to the second embodiment, the same effects as those of the first embodiment can be achieved.

[0112] While the inertial sensor and vehicle of the present invention have been described above based on the illustrated embodiments, the present invention is not limited thereto. The configurations of the various components can be replaced with any configuration having the same function. Furthermore, any other configurations may be added to the present invention. Furthermore, the various embodiments and variations may be appropriately combined.

Claims

1. An inertial sensor, characterized in that: have: A package having a storage space; a sensor unit disposed in the storage space and including a first acceleration sensor element and a first angular velocity sensor element; a second angular velocity sensor element disposed in the housing space in an exposed state, and having an angular velocity detection axis identical to that of the first angular velocity sensor element; and A circuit element is disposed in the housing space and is electrically connected to the sensor unit and the second angular velocity sensor element.

2. The inertial sensor according to claim 1, wherein The second angular velocity sensor element is arranged to overlap with at least one of the sensor unit and the circuit element when viewed in plan from a direction along the angular velocity detection axis.

3. The inertial sensor according to claim 2, wherein: The second angular velocity sensor element is supported by the package via a supporting substrate.

4. The inertial sensor according to claim 1, wherein When the directions perpendicular to the angular velocity detection axis and perpendicular to each other are defined as the first axis direction and the second axis direction, A length of the second angular velocity sensor element in the first axis direction is greater than a length of the first angular velocity sensor element in the first axis direction.

5. The inertial sensor according to claim 4, wherein A length of the second angular velocity sensor element in the second axis direction is greater than a length of the first angular velocity sensor element in the second axis direction.

6. The inertial sensor according to claim 4, wherein A length of the second angular velocity sensor element in the first axis direction is greater than a length of the first acceleration sensor element in the first axis direction.

7. The inertial sensor according to claim 4, wherein: A length of the second angular velocity sensor element in the second axis direction is greater than a length of the first acceleration sensor element in the second axis direction.

8. The inertial sensor according to claim 1, wherein The storage space is decompressed.

9. The inertial sensor according to claim 1, wherein An offset error of an output signal of the second angular velocity sensor element is smaller than an offset error of an output signal of the first angular velocity sensor element.

10. The inertial sensor according to claim 1, wherein The circuit element includes an alignment processing unit that corrects an angular error between the angular velocity detection axes of the first angular velocity sensor element and the second angular velocity sensor element.

11. The inertial sensor according to claim 1, wherein The sensor unit comprises: three first acceleration sensor elements arranged such that their acceleration detection axes are perpendicular to each other; and the three first angular velocity sensor elements are arranged so that the angular velocity detection axes are perpendicular to each other, The angular velocity detection axis of the second angular velocity sensor element is the same as the angular velocity detection axis of any one of the first angular velocity sensor elements.

12. A vehicle, characterized in that: The vehicle includes the inertial sensor according to any one of claims 1 to 11, The angular velocity detection axis is along the yaw axis.

Images