Inertial Sensor Module

Abstract

To provide an inertial sensor module that has excellent detection accuracy.SOLUTION: An inertial sensor module 1 comprises: a first sensor 100 that has a first axis, a second axis, and a third axis as detection axes; and a second sensor 200 that has higher accuracy than the first sensor 100 and has the third axis as a detection axis. The first sensor 100 and the second sensor 200 are arranged on an inner bottom surface 2a that is one plane in a package 2, and the first sensor 100 and the second sensor 200 are hermetically sealed by the package 2.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an inertial sensor module. [Background technology]

[0002] In recent years, physical quantity sensors manufactured using MEMS (Micro Electro Mechanical Systems) technology have been developed. For example, Patent Document 1 discloses an example of such a physical quantity sensor, which includes a three-axis acceleration sensor and a three-axis gyro sensor on a base substrate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-31358 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the physical quantity sensor described in Patent Document 1 detects acceleration and angular velocity based on a change in capacitance between a movable electrode and a fixed electrode, and there is a demand for even higher accuracy. [Means for solving the problem]

[0005] The inertial sensor module includes a first sensor having a first axis, a second axis, and a third axis as its detection axes, and a second sensor having higher accuracy than the first sensor and having the third axis as its detection axis, the first sensor and the second sensor being arranged on one plane within a package, and the first sensor and the second sensor being hermetically sealed by the package. [Brief explanation of the drawings]

[0006] [Figure 1]FIG. 1 is a plan view showing a schematic structure of an inertial sensor module according to a first embodiment. [Figure 2] Cross-sectional view taken along line AA in FIG. [Figure 3] FIG. 2 is a cross-sectional view taken along line BB in FIG. [Figure 4] FIG. 2 is a cross-sectional view taken along line CC in FIG. [Figure 5] FIG. 2 is a plan view of a first gyro sensor element included in the first sensor of FIG. 1. [Figure 6] FIG. 2 is a plan view of a second gyro sensor element included in the first sensor of FIG. 1; [Figure 7] 2 is a plan view of a third gyro sensor element included in the first sensor of FIG. 1; [Figure 8] FIG. 2 is a plan view of a gyro sensor element included in the second sensor of FIG. 1. [Figure 9] 2 is a plan view of a first acceleration sensor element included in the third sensor of FIG. 1; [Figure 10] 1. FIG. 4 is a plan view of a second acceleration sensor element included in the third sensor of FIG. [Figure 11] 1. FIG. 4 is a plan view of a third acceleration sensor element included in the third sensor of FIG. [Figure 12] FIG. 10 is a plan view showing a schematic structure of an inertial sensor module according to a second embodiment. [Figure 13] 13 is a cross-sectional view taken along line DD in FIG. 12. [Figure 14] FIG. 10 is a plan view showing a schematic structure of an inertial sensor module according to a third embodiment. [Figure 15] FIG. 15 is a cross-sectional view taken along line EE in FIG. [Figure 16] FIG. 10 is a plan view showing a schematic structure of an inertial sensor module according to a fourth embodiment. [Figure 17] 17 is a cross-sectional view taken along line FF in FIG. 16. DETAILED DESCRIPTION OF THE INVENTION

[0007] 1. First embodiment 1.1.Inertial Sensor Module First, an inertial sensor module 1 according to a first embodiment will be described with reference to FIGS.

[0008] For ease of explanation, Fig. 1 omits the illustration of the lid 5 and the lids 10a, 20a, and 30a of the sensors 100, 200, and 300. Also, Figs. 1 to 4 omit the illustration of the connection terminals formed on the back surface 2b of the package 2 and the wiring formed on the inner bottom surface 2a that electrically connects the connection terminals to the sensors 100, 200, and 300. Also, Figs. 1 to 4 omit the illustration of the first gyro sensor element 101, the second gyro sensor element 102, the third gyro sensor element 103, the vibration gyro sensor element 201, the first acceleration sensor element 301, the second acceleration sensor element 302, and the third acceleration sensor element 303 in a simplified form.

[0009] In the plan views and cross-sectional views that follow, three mutually orthogonal axes, the X-axis, the Y-axis, and the Z-axis, are illustrated. In this specification, the first axis is the X-axis, the second axis is the Y-axis, and the third axis is the Z-axis. The direction along the X-axis is referred to as the "X-direction," the direction along the Y-axis is referred to as the "Y-direction," and the direction along the Z-axis is referred to as the "Z-direction." The tip of the arrow in each axial direction is also referred to as the "plus side," the base end as the "minus side," the plus side of the Z direction as "up," and the minus side of the Z direction as "down." The Z-direction is along the vertical direction, and the XY plane is along the horizontal plane. In this specification, the plus and minus directions are collectively referred to as the X-direction, the Y-direction, and the Z-direction.

[0010] 1 to 4, the inertial sensor module 1 according to this embodiment includes a package 2 having a base substrate 3 and a lid 5, a first sensor 100, a second sensor 200, and a third sensor 300. The first sensor 100, the second sensor 200, and the third sensor 300 are housed in an internal space S defined by the base substrate 3 and the lid 5 of the package 2, and are hermetically sealed.

[0011] The first sensor 100 is a three-axis physical quantity sensor. The physical quantity is, for example, angular velocity, but may also be acceleration or another physical quantity. For example, if the physical quantity is angular velocity, the first sensor 100 is a three-axis angular velocity sensor, and for example, if the physical quantity is acceleration, the first sensor 100 is a three-axis acceleration sensor. The first sensor 100 of this embodiment is a three-axis gyro sensor that includes a first gyro sensor element 101, a second gyro sensor element 102, and a third gyro sensor element 103, and is capable of measuring angular velocity around the X-axis, which is the first axis, around the Y-axis, which is the second axis, and around the Z-axis, which is the third axis. The first gyro sensor element 101, the second gyro sensor element 102, and the third gyro sensor element 103 are gyro sensor elements manufactured by processing a silicon substrate using MEMS technology, and detect angular velocity based on a change in capacitance between a movable electrode and a fixed electrode.

[0012] The second sensor 200 is a physical quantity sensor that can detect physical quantities with higher accuracy than the first sensor 100. When the first sensor 100 is a three-axis angular velocity sensor, the second sensor 200 may be an angular velocity sensor that uses one of the three axes of the first sensor 100 as a detection axis. Furthermore, when the first sensor 100 is a three-axis acceleration sensor, the second sensor 200 may be an acceleration sensor that uses one of the three axes of the first sensor 100 as a detection axis. The second sensor 200 of this embodiment is a uniaxial gyro sensor that includes a vibration gyro sensor element 201 and can measure angular velocity around the Z axis, which is the third axis. The vibration gyro sensor element 201 is a gyro sensor element manufactured by processing a quartz substrate using photolithography technology, and converts vibrations of the detection vibrating arm into an electrical signal to detect angular velocity. In addition, since the base material is quartz, it has excellent temperature characteristics. Therefore, compared to gyro sensor elements manufactured using MEMS technology, it is less susceptible to external noise and temperature effects and has high detection accuracy.

[0013] The first sensor 100 is a triaxial angular velocity sensor, and the third sensor 300 includes a first acceleration sensor element 301, a second acceleration sensor element 302, and a third acceleration sensor element 303. The triaxial acceleration sensor can measure acceleration in the X direction (first axis), the Y direction (second axis), and the Z direction (third axis). The first acceleration sensor element 301, the second acceleration sensor element 302, and the third acceleration sensor element 303 are acceleration sensor elements manufactured using MEMS technology, and detect acceleration based on changes in capacitance between a movable electrode and a fixed electrode. Furthermore, when the first sensor 100 is a triaxial acceleration sensor, the third sensor 300 may be a triaxial angular velocity sensor. That is, the third sensor 300 may be a sensor different from the first sensor 100. Furthermore, the third sensor 300 may be omitted.

[0014] Therefore, the inertial sensor module 1 of this embodiment is a six-axis combo sensor that includes a three-axis gyro sensor, a one-axis gyro sensor, and a three-axis acceleration sensor within the package 2. The inertial sensor module 1 may also be a six-axis combo sensor that includes a three-axis acceleration sensor, a one-axis acceleration sensor, and a three-axis gyro sensor within the package 2.

[0015] The package 2 has a rectangular shape in a plan view, and includes a base substrate 3 and a lid 5.

[0016] The base substrate 3 has a recess 4 that is recessed downward, and a first sensor 100, a second sensor 200, and a third sensor 300 are housed in the recess 4. The first sensor 100, the second sensor 200, and the third sensor 300 are arranged on the inner bottom surface 2a, which is the same plane as the base substrate 3. The first sensor 100, the second sensor 200, and the third sensor 300 are electrically connected to wiring (not shown) provided on the inner bottom surface 2a.

[0017] Therefore, the first sensor 100, the second sensor 200, and the third sensor 300 are arranged on the inner bottom surface 2a, which is a single flat surface within the package 2, thereby realizing an inertial sensor module 1 with excellent axis alignment accuracy. In particular, by improving the Z-axis alignment accuracy between the third gyro sensor element 103, which detects the angular velocity of the first sensor 100 about the Z axis, and the vibration gyro sensor element 201, which detects the angular velocity of the second sensor 200 about the Z axis with high accuracy, it is possible to improve the accuracy of angular velocity measurement about the Z axis.

[0018] As a constituent material of the base substrate 3, various ceramics such as oxide ceramics, nitride ceramics, and carbide ceramics are suitable, but silicon, glass, etc. may also be used.

[0019] The lid 5 is placed on the base substrate 3 to hermetically seal the first sensor 100, the second sensor 200, and the third sensor 300 arranged on the base substrate 3.

[0020] The lid body 5 is bonded to the upper surface of the base substrate 3 via a bonding member (not shown) such as glass frit. As a result, an airtight internal space S is formed between the base substrate 3 and the lid body 5, and the first sensor 100, the second sensor 200, and the third sensor 300 are housed in this internal space S.

[0021] The degree of vacuum in the internal space S is preferably set to 1000 Pa or less, and more preferably 100 Pa or more and 500 Pa or less. Furthermore, the atmosphere in the internal space S is not particularly limited, but is preferably an inert atmosphere such as nitrogen or argon. This can reduce deterioration over time of the first sensor 100, the second sensor 200, and the third sensor 300, and can improve the reliability of the sensors.

[0022] The lid 5 is preferably made of various ceramics such as oxide ceramics, nitride ceramics, and carbide ceramics, but may also be made of silicon, glass, metal, or the like.

[0023] The base substrate 3 and the lid 5 of this embodiment are made of ceramic, and therefore the package 2 of this embodiment is made of ceramic.

[0024] Next, the first sensor 100, the second sensor 200, and the third sensor 300 will be described in detail with reference to FIGS.

[0025] 1.2. First Sensor 2, the first sensor 100 has a substrate 10, a lid 10a, a first gyro sensor element 101, a second gyro sensor element 102, and a third gyro sensor element 103. The first gyro sensor element 101, the second gyro sensor element 102, and the third gyro sensor element 103 are housed in an internal space S1 defined by the substrate 10 and the lid 10a. The internal space S1 is an airtight space and is in a reduced pressure state, preferably closer to a vacuum.

[0026] In the first sensor 100, the first gyro sensor element 101 detects an angular velocity around the X axis, the second gyro sensor element 102 detects an angular velocity around the Y axis, and the third gyro sensor element 103 detects an angular velocity around the Z axis.

[0027] The substrate 10 has three recesses 11, 12, and 13 formed therein that are recessed downward, and a first gyro sensor element 101, a second gyro sensor element 102, and a third gyro sensor element 103 are arranged on the substrate 10 so as to correspond to the recesses 11, 12, and 13, respectively. The recesses 11, 12, and 13 function as relief portions to prevent contact between the gyro sensor elements 101, 102, and 103 and the substrate 10, respectively. Furthermore, a fixed detection electrode portion 146 that faces the first gyro sensor element 101 is arranged on the bottom surface of the recess 11, and a fixed detection electrode portion 146 that faces the second gyro sensor element 102 is arranged on the bottom surface of the recess 12.

[0028] The substrate 10 is formed primarily from a glass material containing alkali metal ions, such as Pyrex (registered trademark) glass. This allows the gyro sensor elements 101, 102, and 103 formed from a silicon substrate to be firmly bonded to the substrate 10 by anodic bonding. The substrate 10 may also be a semiconductor substrate such as silicon. The gyro sensor elements 101, 102, and 103 may also be formed by stacking polysilicon or the like on the substrate 10. In other words, the gyro sensor elements 101, 102, and 103 may be manufactured by a manufacturing method that complies with a silicon semiconductor process.

[0029] The lid body 10a has an upwardly recessed recess 11a formed therein, and when joined to the substrate 10, an internal space S1 is formed, which can accommodate the first gyro sensor element 101, the second gyro sensor element 102, and the third gyro sensor element 103. In this embodiment, the lid 10a is made of a silicon substrate, which allows the lid 10a and the substrate 10 to be firmly bonded together by anodic bonding.

[0030] The first gyro sensor element 101, the second gyro sensor element 102, and the third gyro sensor element 103 will be described below.

[0031] 1.2.1. First Gyro Sensor Element First, the configuration of the first gyro sensor element 101 will be described with reference to FIG. As shown in Fig. 5, the first gyro sensor element 101 includes a structure 111. The structure 111 has a vibrating body 134, a movable body 140, and a movable detection electrode portion 144. In Fig. 5, the structure 111 further has a fixed portion 130, a drive spring portion 132, a movable drive electrode portion 136, fixed drive electrode portions 138a and 138b, and a beam portion 142.

[0032] The fixed portion 130, drive spring portion 132, vibrating body 134, movable drive electrode portion 136, movable body 140, beam portion 142, and movable detection electrode portion 144 are integrally formed by patterning a silicon substrate, for example.

[0033] The material of the fixed portion 130, the drive spring portion 132, the vibrating body 134, the movable drive electrode portion 136, the fixed drive electrode portions 138a, 138b, the movable body 140, the beam portion 142, and the movable detection electrode portion 144 is silicon that has been made conductive by being doped with impurities such as phosphorus or boron.

[0034] The vibrating body 134 is provided on the recess 11 of the substrate 10. In the example shown in FIG. 5, the vibrating body 134 is a rectangular frame in a plan view, and is composed of a first extending portion 135a extending in the Y direction and a second extending portion 135b extending in the X direction. The Y-direction side surface of the vibrating body 134 is connected to the drive spring portion 132. The vibrating body 134 can vibrate in the Y direction by the movable drive electrode portion 136 and the fixed drive electrode portions 138a and 138b.

[0035] The fixing portions 130 are fixed to the substrate 10. The fixing portions 130 are bonded to the upper surface of the substrate 10 by, for example, anodic bonding. In the illustrated example, four fixing portions 130 are provided.

[0036] The drive spring portion 132 connects the fixed portion 130 (130a, 130b, 130c, 130d) and the vibrating body 134. In the illustrated example, the drive spring portion 132 has four springs 132a, 132b, 132c, 132d. The spring 132a connects the fixed portion 130a and the vibrating body 134. The spring 132b connects the fixed portion 130b and the vibrating body 134. The spring 132c connects the fixed portion 130c and the vibrating body 134. The spring 132d connects the fixed portion 130d and the vibrating body 134.

[0037] The springs 132a, 132b, 132c, and 132d extend in the Y direction while reciprocating in the X direction. In a plan view, the springs 132a and 132b are arranged symmetrically with respect to an axis α that passes through the center O of the vibrating body 134 and is parallel to the X axis. Similarly, the springs 132c and 132d are arranged symmetrically with respect to the axis α. In addition, in a plan view, the springs 132a and 132c are arranged symmetrically with respect to an axis β that passes through the center O of the vibrating body 134 and is parallel to the Y axis. Similarly, the springs 132b and 132d are arranged symmetrically with respect to the axis β. This suppresses deformation of the drive spring portion 132 in the X and Z directions, and allows it to smoothly expand and contract in the Y direction, which is the vibration direction of the vibrating body 134.

[0038] The movable driving electrode section 136 is provided on the vibrating body 134. More specifically, the movable driving electrode section 136 is connected to the first extending section 135a of the vibrating body 134. In the example shown in the figure, four movable driving electrode sections 136 are provided. As shown in FIG. 5, the movable driving electrode section 136 is a comb-like electrode having a trunk section extending in the X direction from the vibrating body 134 and a plurality of branch sections extending in the Y direction from the trunk section.

[0039] The fixed drive electrode portions 138a and 138b are fixed to the substrate 10. The fixed drive electrode portions 138a and 138b are bonded to the upper surface of the substrate 10 by, for example, anodic bonding. The fixed drive electrode portions 138a and 138b are provided opposite the movable drive electrode portion 136, and the movable drive electrode portion 136 is disposed between the fixed drive electrode portions 138a and 138b. In the illustrated example, the fixed drive electrode portion 138a is provided on the negative Y direction side of the movable drive electrode portion 136, and the fixed drive electrode portion 138b is provided on the positive Y direction side of the movable drive electrode portion 136. As shown in FIG. 5, the movable drive electrode portion 136 has a comb-like shape, and the fixed drive electrode portions 138a and 138b have comb-like shapes that correspond to the shape of the movable drive electrode portion 136.

[0040] The movable body 140 is provided on the recess 11. The movable body 140 is supported by the vibrating body 134 via beam portions 142. In a plan view, the movable body 140 is provided inside the frame-shaped vibrating body 134. The movable body 140 has a plate-like shape. The movable body 140 is connected to the Y-direction side surface of the second extending portion 135b of the vibrating body 134 by the beam portions 142, which serve as the rotation axis.

[0041] Beam portion 142 is provided at a position offset from the center of gravity of movable body 140. Beam portion 142 is provided along the Y axis. Beam portion 142 is capable of torsional deformation, and this torsional deformation can displace movable body 140 in the Z direction. In the illustrated example, movable body 140 extends from beam portion 142 in the positive X direction, but the extension direction of movable body 140 is not particularly limited.

[0042] The movable detection electrode portion 144 is provided on the movable body 140. In the illustrated example, the movable detection electrode portion 144 is a portion of the movable body 140 that overlaps with the fixed detection electrode portion 146 in a plan view. The movable detection electrode portion 144 is a portion of the movable body 140 that forms a capacitance with the fixed detection electrode portion 146. In the first gyro sensor element 101, the movable detection electrode portion 144 may be provided by making the movable body 140 out of a conductive material, or the movable detection electrode portion 144 made of a conductor layer such as metal may be provided on the surface of the movable body 140. In the illustrated example, the movable detection electrode portion 144 is provided by making the movable body 140 out of a conductive material, for example, silicon doped with impurities.

[0043] The fixed detection electrode portion 146 is disposed on the substrate 10 and is provided opposite the movable detection electrode portion 144. The fixed detection electrode portion 146 is provided, for example, on the bottom surface of the recess 11. In the example shown in Fig. 5, the planar shape of the fixed detection electrode portion 146 is rectangular.

[0044] Suitable materials for the fixed detection electrode 146 include, for example, an elemental metal such as Au, Pt, Ag, Cu, Al, In, Zn, Pt, Sn, or an alloy or conductive oxide containing any of these. By using a transparent electrode material such as ITO (indium tin oxide) as the fixed detection electrode 146, foreign matter present on the fixed detection electrode 146 can be easily seen from below the base substrate 3 when the substrate 10 is a transparent glass substrate.

[0045] Next, the operation of the first gyro sensor element 101 will be described. When a voltage is applied between the movable drive electrode portion 136 and the fixed drive electrode portions 138a, 138b, an electrostatic force can be generated between the movable drive electrode portion 136 and the fixed drive electrode portions 138a, 138b. This causes the drive spring portion 132 to expand and contract in the Y direction, while vibrating the vibrating body 134 in the Y direction. Note that by reducing the distance between the movable drive electrode portion 136 and the fixed drive electrode portions 138a, 138b, the electrostatic force acting between the movable drive electrode portion 136 and the fixed drive electrode portions 138a, 138b can be increased.

[0046] More specifically, a first alternating voltage is applied between the movable driving electrode portion 136 and the fixed driving electrode portion 138a, and a second alternating voltage that is 180 degrees out of phase with the first alternating voltage is applied between the movable driving electrode portion 136 and the fixed driving electrode portion 138b.

[0047] As described above, the movable body 140 is supported by the vibrating body 134 via the beams 142, and therefore the movable body 140 also vibrates in the Y direction as the vibrating body 134 vibrates.

[0048] When an angular velocity ωx about the X-axis is applied to the first gyro sensor element 101 while the vibrating body 134 is vibrating in the Y-axis direction, a Coriolis force acts, and the movable body 140 is displaced in the Z-axis direction. As the movable body 140 is displaced in the Z-axis direction, the movable detection electrode portion 144 moves closer to or further away from the fixed detection electrode portion 146. As a result, the capacitance C11 between the movable detection electrode portion 144 and the fixed detection electrode portion 146 changes. By detecting the amount of change in the capacitance C11 between the movable detection electrode portion 144 and the fixed detection electrode portion 146, the angular velocity ωx about the X-axis can be obtained.

[0049] In the above, an electrostatic drive method has been described, in which the vibrating body 134 is driven by electrostatic force. However, the method for driving the vibrating body 134 is not particularly limited, and a piezoelectric drive method, an electromagnetic drive method using the Lorentz force of a magnetic field, or the like can be applied.

[0050] 1.2.2. Second Gyro Sensor Element Next, the second gyro sensor element 102 will be described with reference to FIG. As shown in Fig. 6, the second gyro sensor element 102 includes a structure 112. The structure 112 has a vibrating body 134, a movable body 140, and a movable detection electrode portion 144. In Fig. 6, the second gyro sensor element 102 further has a fixed portion 130, a drive spring portion 132, a movable drive electrode portion 136, fixed drive electrode portions 138a and 138b, and a beam portion 142.

[0051] The vibrating body 134 and the movable body 140 of the second gyro sensor element 102 are provided on the recess 12. The fixed detection electrode portion 146 for the second gyro sensor element 102 is provided on the bottom surface of the recess 12, for example.

[0052] As shown in Fig. 6, the second gyro sensor element 102 is configured by rotating the first gyro sensor element 101 shown in Fig. 5 by 90 degrees around the Z axis as the rotation axis. Therefore, detailed description of the second gyro sensor element 102 will be omitted.

[0053] In the second gyro sensor element 102, the vibrating body 134 vibrates in the X direction, and when an angular velocity ωy about the Y axis is applied while the vibrating body 134 is vibrating in the X direction, a Coriolis force acts and the movable body 140 is displaced in the Z direction. This changes the capacitance C12 between the movable detection electrode portion 144 and the fixed detection electrode portion 146, and the angular velocity ωy about the Y axis can be obtained.

[0054] 1.2.3.Third Gyro Sensor Element Next, the configuration of the third gyro sensor element 103 will be described with reference to FIG. Hereinafter, in the third gyro sensor element 103 shown in FIG. 7, components having the same functions as those of the first gyro sensor element 101 shown in FIG. 5 are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0055] As shown in Fig. 7, the third gyro sensor element 103 includes a structure 113. The structure 113 has a vibrating body 134, a movable body 150, a movable detection electrode portion 154, and a fixed detection electrode portion 156. In Fig. 7, the structure 113 further has a fixed portion 130, a drive spring portion 132, a movable drive electrode portion 136, fixed drive electrode portions 138a and 138b, and a detection spring portion 152.

[0056] The movable body 150 is provided on the recess 13. The movable body 150 is supported by the vibrating body 134 via a detection spring portion 152. The movable body 150 is provided inside the frame-shaped vibrating body 134 in a plan view. In the example shown in FIG. 7, the movable body 150 is a rectangular frame in a plan view, and is composed of a third extension portion 151a extending in the Y direction and a fourth extension portion 151b extending in the X direction. The side surface of the movable body 150 in the X direction is connected to the detection spring portion 152.

[0057] The detection spring portion 152 connects the vibrating body 134 and the movable body 150. In the illustrated example, the detection spring portion 152 has four springs 152a, 152b, 152c, and 152d. The springs 152a and 152b connect the first extension portion 135a, which is arranged on the negative X-direction side of the movable body 150, to the movable body 150. The springs 152c and 152d connect the first extension portion 135a, which is arranged on the positive X-direction side of the movable body 150, to the movable body 150.

[0058] The springs 152a, 152b, 152c, and 152d extend in the X direction while reciprocating in the Y direction. In a plan view, the springs 152a and 152b are symmetrically arranged with respect to an axis α that passes through the center O of the vibrating body 134 and is parallel to the X axis. Similarly, the springs 152c and 152d are symmetrically arranged with respect to the axis α. In addition, in a plan view, the springs 152a and 152c are symmetrically arranged with respect to an axis β that passes through the center O of the vibrating body 134 and is parallel to the Y axis. Similarly, the springs 152b and 152d are symmetrically arranged with respect to the axis β. This suppresses deformation of the detection spring unit 152 in the Y and Z directions, allowing it to smoothly expand and contract in the X direction, which is the displacement direction of the movable body 150.

[0059] The movable detection electrode portion 154 is provided on the movable body 150. The movable detection electrode portion 154 extends in the Y direction, for example, from one fourth extension portion 151b to the other fourth extension portion 151b of the movable body 150. In the illustrated example, two movable detection electrode portions 154 are provided.

[0060] The fixed detection electrode portion 156 is fixed to the substrate 10 and is provided opposite the movable detection electrode portion 154. The fixed detection electrode portion 156 is bonded to the bottom surface of the recess 13 by, for example, anodic bonding. The fixed detection electrode portion 156 is provided inside the frame-shaped movable body 150. In the example shown in the figure, the fixed detection electrode portion 156 is provided so as to sandwich the movable detection electrode portion 154 therebetween.

[0061] The fixed portion 130, drive spring portion 132, vibrating body 134, movable drive electrode portion 136, movable body 150, detection spring portion 152, and movable detection electrode portion 154 are integrally formed by, for example, patterning a silicon substrate. The material of the fixed portion 130, drive spring portion 132, vibrating body 134, movable drive electrode portion 136, fixed drive electrode portions 138a and 138b, movable body 150, detection spring portion 152, movable detection electrode portion 154, and fixed detection electrode portion 156 is, for example, silicon doped with impurities such as phosphorus or boron to provide conductivity.

[0062] Next, the operation of the third gyro sensor element 103 will be described. When a voltage is applied between the movable drive electrode portion 136 and the fixed drive electrode portions 138a, 138b, an electrostatic force can be generated between the movable drive electrode portion 136 and the fixed drive electrode portions 138a, 138b. This causes the drive spring portion 132 to expand and contract in the Y direction, while vibrating the vibrating body 134 in the Y direction.

[0063] As described above, the movable body 150 is supported by the vibrating body 134 via the detection spring portion 152, and therefore the movable body 150 also vibrates in the Y direction in accordance with the vibration of the vibrating body 134.

[0064] When an angular velocity ωz about the Z axis is applied to the third gyro sensor element 103 while the vibrating body 134 is vibrating in the Y direction, a Coriolis force acts, and the movable body 150 is displaced in the X direction. As the movable body 150 is displaced in the X direction, the distance between the movable detection electrode portion 154 and the fixed detection electrode portion 156 changes. Therefore, the capacitance C13 between the movable detection electrode portion 154 and the fixed detection electrode portion 156 changes. By detecting the amount of change in the capacitance C13 between the movable detection electrode portion 154 and the fixed detection electrode portion 156, the angular velocity ωz about the Z axis can be obtained.

[0065] As described above, the first sensor 100 can measure angular velocities around the X-axis, Y-axis, and Z-axis, which are three axes that are perpendicular to one another.

[0066] 1.3. Secondary Sensor 3, the second sensor 200 has a substrate 20, a lid 20a, and a vibration gyro sensor element 201. The vibration gyro sensor element 201 is housed in an internal space S2 defined by the substrate 20 and the lid 20a. The internal space S2 is an airtight space and is in a reduced pressure state, preferably closer to a vacuum.

[0067] In the second sensor 200, the vibration gyro sensor element 201 detects the angular velocity around the Z axis, which is the third axis.

[0068] The vibrating gyro sensor element 201 is formed using quartz crystal, which is a piezoelectric material, as a base material. Quartz crystal has an X axis called the electrical axis, a Y axis called the mechanical axis, and a Z axis called the optical axis. The quartz crystal substrate constituting the vibrating gyro sensor element 201 is cut along a plane defined by the X-axis and Y-axis, which are orthogonal to the quartz crystal axes, and processed into a flat plate, and has a predetermined thickness in the Z-axis direction, which is orthogonal to the plane. The predetermined thickness is set appropriately depending on the resonant frequency, outer size, workability, etc.

[0069] The vibrating gyro sensor element 201 is formed by etching using photolithography technology. A plurality of the vibrating gyro sensor elements 201 can be obtained from one quartz substrate.

[0070] In plan view, the substrate 20 has a convex portion 21 formed in the center thereof that protrudes upward, and the vibrating gyro sensor element 201 is disposed on the upper surface of the convex portion 21. Therefore, contact between the vibrating gyro sensor element 201 and the substrate 20 can be prevented.

[0071] The cover 20a has an upwardly recessed recess 21a formed therein, and when joined to the substrate 20, an internal space S2 is formed in which the vibrating gyro sensor element 201 can be housed.

[0072] Next, the configuration of the vibration gyro sensor element 201 will be described with reference to FIG. As shown in FIG. 8, the vibration gyro sensor element 201 has a configuration called a double T type. The vibration gyro sensor element 201 comprises a base 22 located at the center, a pair of detection vibration arms 23a, 23b extending from the base 22 in the Y direction, a pair of connecting arms 24a, 24b extending from the base 22 in the X direction so as to be perpendicular to the detection vibration arms 23a, 23b, and a pair of drive vibration arms 25a, 25b, 26a, 26b extending in the Y direction from the tip side of each connecting arm 24a, 24b so as to be parallel to the detection vibration arms 23a, 23b.

[0073] Furthermore, in the vibrating gyro sensor element 201, detection electrodes (not shown) are formed on the detection vibrating arms 23a and 23b, and drive electrodes (not shown) are formed on the drive vibrating arms 25a, 25b, 26a, and 26b. The vibration gyro sensor element 201 has detection vibration arms 23a and 23b that form a detection vibration system that detects angular velocity, and connecting arms 24a and 24b and drive vibration arms 25a, 25b, 26a, and 26b that form a drive vibration system that drives the vibration gyro sensor element 201.

[0074] Weights 27a and 27b are formed at the tip of each of the detection vibrating arms 23a and 23b, and weights 28a, 28b, 29a, and 29b are formed at the tip of each of the drive vibrating arms 25a, 25b, 26a, and 26b. This allows the vibration gyro sensor element 201 to be miniaturized and have improved angular velocity detection sensitivity.

[0075] The vibrating gyro sensor element 201 is arranged so as to overlap, in plan view, a protrusion 21 that protrudes upward and is provided on the substrate 20. Specifically, the base 22 and the protrusion 21 are arranged so as to overlap each other. In addition, on the surface of the base 22 of the vibration gyro sensor element 201 facing the protrusion 21, there are formed extraction electrodes (not shown) that are drawn out from each of the detection electrodes and each of the drive electrodes, and each extraction electrode is electrically and mechanically connected to an external connection terminal (not shown) that is formed on the surface of the protrusion 21 facing the base 22 via a metal bump 90 or the like. As a result, the vibrating gyro sensor element 201 is held on the substrate 20.

[0076] Here, the operation of the vibration gyro sensor element 201 of the second sensor 200 will be described.

[0077] In the driving vibration state of the vibrating gyro sensor element 201, when a drive signal is applied from the outside, the driving vibration arms 25a, 25b, 26a, and 26b of the vibrating gyro sensor element 201 perform bending vibration in the X direction in a state where no angular velocity is applied. Note that the driving vibration arms 25a and 25b and the driving vibration arms 26a and 26b vibrate in opposite phases to each other.

[0078] Next, when an angular velocity ωz about the Z axis is applied to the vibrating gyro sensor element 201 while this drive vibration is being performed, a Y-direction Coriolis force acts on the drive vibration arms 25a, 25b, 26a, and 26b and the connecting arms 24a and 24b that constitute the drive vibration system of the vibrating gyro sensor element 201. Note that a Y-direction Coriolis force acts in opposite phase on the drive vibration arms 25a and 25b and the connecting arm 24a, and on the drive vibration arms 26a, 26b and the connecting arm 24b. At the same time, the detection vibration arm 23a deforms in the plus X direction in response to the Coriolis force in the minus Y direction, and the detection vibration arm 23b deforms in the minus X direction in response to the Coriolis force in the plus Y direction.

[0079] Thereafter, a Coriolis force, which is a returning force in the opposite direction to the Y direction, acts on the drive vibration arms 25a, 25b, 26a, 26b and the connecting arms 24a, 24b. At the same time, the detection vibration arm 23a deforms in the minus X direction in response to the Coriolis force in the plus Y direction, and the detection vibration arm 23b deforms in the plus X direction in response to the Coriolis force in the minus Y direction.

[0080] When an angular velocity ωz about the Z axis is applied to the vibrating gyro sensor element 201, the vibrating gyro sensor element 201 alternately repeats this series of operations to generate new bending vibrations in the detection vibrating arms 23a and 23b. The vibration gyro sensor element 201 detects the distortion of the quartz crystal caused by the vibration as an electric signal using detection electrodes formed on the detection vibrating arms 23a and 23b, thereby determining the angular velocity ωz.

[0081] As described above, the second sensor 200 can measure the angular velocity around the Z axis with high accuracy.

[0082] 1.4.Third Sensor 1 and 4, the third sensor 300 includes a substrate 30, a cover 30a, a first acceleration sensor element 301, a second acceleration sensor element 302, and a third acceleration sensor element 303. The first acceleration sensor element 301, the second acceleration sensor element 302, and the third acceleration sensor element 303 are housed in an internal space S3 defined by the substrate 30 and the cover 30a. The internal space S3 is preferably an airtight space filled with an inert gas such as nitrogen, helium, or argon, and is preferably maintained at an operating temperature of approximately −40°C to 125°C and at approximately atmospheric pressure. However, the atmosphere in the internal space S3 is not particularly limited and may be, for example, reduced pressure or pressurized.

[0083] In the third sensor 300, the first acceleration sensor element 301 detects acceleration in the X direction, the second acceleration sensor element 302 detects acceleration in the Y direction, and the third acceleration sensor element 303 detects acceleration in the Z direction.

[0084] The substrate 30 has three downwardly recessed portions 31, 32, and 33 formed therein, and the first acceleration sensor element 301, the second acceleration sensor element 302, and the third acceleration sensor element 303 are arranged on the substrate 30 so as to correspond to the recessed portions 31, 32, and 33, respectively. The recessed portions 31, 32, and 33 function as relief portions to prevent contact between the acceleration sensor elements 301, 302, and 303 and the substrate 30, respectively. Furthermore, on the bottom surface of the recess 33, a first detection electrode 741 and a second detection electrode 742 that face the third acceleration sensor element 303 are arranged.

[0085] The substrate 30 is primarily made of a glass material containing alkali metal ions, such as Pyrex (registered trademark) glass. This allows the acceleration sensor elements 301, 302, and 303, which are made of a silicon substrate, to be firmly bonded to the substrate 30 by anodic bonding. The substrate 30 may also be a semiconductor substrate made of silicon or the like. The acceleration sensor elements 301, 302, and 303 may also be formed by stacking polysilicon or the like on the substrate 30. In other words, the acceleration sensor elements 301, 302, and 303 may be manufactured using a manufacturing method that complies with a silicon semiconductor process.

[0086] The lid body 30a has an upwardly recessed recess 31a formed therein, and when joined to the substrate 30, an internal space S3 is formed, which can accommodate the first acceleration sensor element 301, the second acceleration sensor element 302, and the third acceleration sensor element 303. In this embodiment, the lid 30a is made of a silicon substrate, which allows the lid 30a and the substrate 30 to be firmly bonded together by anodic bonding.

[0087] The first acceleration sensor element 301, the second acceleration sensor element 302, and the third acceleration sensor element 303 will be described below.

[0088] 1.4.1. First Acceleration Sensor Element First, the configuration of the first acceleration sensor element 301 will be described with reference to FIG. 9, the first acceleration sensor element 301 has support portions 41 and 42, a movable portion 43, connecting portions 44 and 45, a plurality of first fixed electrode fingers 48, and a plurality of second fixed electrode fingers 49. The movable portion 43 has a base portion 431 and a plurality of movable electrode fingers 432 protruding from the base portion 431 on both sides in the Y direction. The first acceleration sensor element 301 is formed from a silicon substrate doped with impurities such as phosphorus or boron.

[0089] The support portions 41 and 42 are each bonded to the upper surface of the substrate 30, and are electrically connected to wiring (not shown). A movable portion 43 is provided between the support portions 41 and 42. The movable portion 43 is connected to the support portion 41 via a connecting portion 44 on the negative X-direction side, and to the support portion 42 via a connecting portion 45 on the positive X-direction side. This allows the movable portion 43 to be displaced in the X-direction relative to the support portions 41 and 42, as indicated by arrow a.

[0090] The plurality of first fixed electrode fingers 48 are arranged on one side of the movable electrode fingers 432 in the X direction, and are arranged in a comb-like shape so as to interdigitate with, and be spaced apart from, the corresponding movable electrode fingers 432. The base ends of the plurality of first fixed electrode fingers 48 are joined to the upper surface of the substrate 30.

[0091] In contrast, the plurality of second fixed electrode fingers 49 are arranged on the other side of the movable electrode fingers 432 in the X direction, and are arranged in a comb-like shape so as to interdigitate with, and be spaced apart from, the corresponding movable electrode fingers 432. The base ends of the plurality of second fixed electrode fingers 49 are joined to the upper surface of the substrate 30.

[0092] The first acceleration sensor element 301 described above detects acceleration in the X direction as follows. That is, when acceleration in the X direction is applied to the inertial sensor module 1, the movable part 43 is displaced in the X direction based on the magnitude of the acceleration while elastically deforming the connecting parts 44 and 45. With this displacement, the magnitudes of the capacitance C1 between the movable electrode finger 432 and the first fixed electrode finger 48 and the capacitance C2 between the movable electrode finger 432 and the second fixed electrode finger 49 each change. Therefore, acceleration can be detected based on the amount of change in these capacitances C1 and C2.

[0093] 1.4.2. Second Acceleration Sensor Element Next, the configuration of the second acceleration sensor element 302 will be described with reference to FIG. 10, the second acceleration sensor element 302 has the same configuration as the first acceleration sensor element 301, except that it is rotated 90° in plan view. That is, the second acceleration sensor element 302 has support portions 51 and 52, a movable portion 53, connecting portions 54 and 55, a plurality of first fixed electrode fingers 58, and a plurality of second fixed electrode fingers 59. The movable portion 53 has a base portion 531 and a plurality of movable electrode fingers 532 protruding from the base portion 531 on both sides in the X direction.

[0094] Supporting portions 51 and 52 are each bonded to the upper surface of substrate 30. Movable portion 53 is provided between supporting portions 51 and 52. Movable portion 53 is connected to supporting portion 51 on the negative Y direction side via connecting portion 54, and is connected to supporting portion 52 on the positive Y direction side via connecting portion 55. This allows movable portion 53 to be displaced in the Y direction relative to supporting portions 51 and 52 as indicated by arrow b.

[0095] The plurality of first fixed electrode fingers 58 are arranged on one side of the movable electrode fingers 532 in the Y direction, and are arranged in a comb-like shape so as to interdigitate with, and be spaced apart from, the corresponding movable electrode fingers 532. The base ends of the plurality of first fixed electrode fingers 58 are joined to the upper surface of the substrate 30.

[0096] In contrast, the plurality of second fixed electrode fingers 59 are arranged on the other side of the movable electrode fingers 532 in the Y direction, and are arranged in a comb-like shape that meshes with the corresponding movable electrode fingers 532 at intervals. The base ends of the plurality of second fixed electrode fingers 59 are joined to the upper surface of the substrate 30.

[0097] The second acceleration sensor element 302 described above detects acceleration in the Y direction as follows. That is, when acceleration in the Y direction is applied to the inertial sensor module 1, the movable part 53 is displaced in the Y direction based on the magnitude of the acceleration while elastically deforming the connecting parts 54 and 55. With this displacement, the magnitudes of the capacitance C3 between the movable electrode finger 532 and the first fixed electrode finger 58 and the capacitance C4 between the movable electrode finger 532 and the second fixed electrode finger 59 each change. Therefore, acceleration can be detected based on the amount of change in these capacitances C3 and C4.

[0098] 1.4.3.Third Acceleration Sensor Element Next, the configuration of the third acceleration sensor element 303 will be described with reference to FIG. As shown in FIG. 11, the third acceleration sensor element 303 has a pair of support parts 61, 62, a movable part 63, and a pair of connecting parts 64, 65 that connect the movable part 63 to the support parts 61, 62 so that the movable part 63 can swing relative to the support parts 61, 62, and is configured so that the movable part 63 swings in a seesaw manner relative to the support parts 61, 62, with the connecting parts 64, 65 as the axis J.

[0099] The support portions 61 and 62 are each bonded to the upper surface of the substrate 30. The movable portion 63 is provided between the support portions 61 and 62. The movable portion 63 has a first movable portion 631 located on the positive Y side of the axis J and a second movable portion 632 located on the negative Y side of the axis J. The first movable portion 631 is disposed opposite a first detection electrode 741 provided on the bottom surface of the recess 33 of the substrate 30, and forms a capacitance C5 between the first detection electrode 741 and the second movable portion 632. The second movable portion 632 is disposed opposite a second detection electrode 742 provided on the bottom surface of the recess 33 of the substrate 30, and forms a capacitance C6 between the second detection electrode 742 and the second detection electrode 742. The third acceleration sensor element 303 is formed from a silicon substrate doped with impurities such as phosphorus or boron.

[0100] The first movable part 631 and the second movable part 632 are designed so that their rotation moments differ when acceleration is applied in the Z direction, which is the vertical direction, and a predetermined inclination occurs in the movable part 63 depending on the acceleration. As a result, when acceleration occurs in the Z direction, the movable part 63 swings in a seesaw manner around the axis J. Specifically, in this embodiment, the length of the second movable part 632 in the Y direction is made larger than the length of the first movable part 631 in a plan view, so that the rotation moment of the second movable part 632 is larger than the rotation moment of the first movable part 631.

[0101] The third acceleration sensor element 303 described above detects acceleration in the Z direction as follows. That is, when acceleration in the Z direction is applied to the inertial sensor module 1, the movable part 63 seesaws around the axis J. This seesaw swing of the movable part 63 changes the distance between the first movable part 631 and the first detection electrode 741 and the distance between the second movable part 632 and the second detection electrode 742, and the capacitances C5 and C6 change accordingly. Therefore, acceleration can be detected based on the amount of change in these capacitances C5 and C6.

[0102] As described above, the third sensor 300 can measure acceleration in the directions of three mutually orthogonal axes, that is, the X-axis, the Y-axis, and the Z-axis.

[0103] As described above, the inertial sensor module 1 of this embodiment has the first sensor 100, the second sensor 200, and the third sensor 300 arranged on the inner bottom surface 2a, which is one flat surface of the package 2, thereby improving the accuracy of axis alignment between the sensors. Also, by improving the accuracy of Z-axis alignment between the third gyro sensor element 103, which detects the angular velocity of the first sensor 100 about the Z axis, and the vibration gyro sensor element 201, which detects the angular velocity of the second sensor 200 about the Z axis with high accuracy, it is possible to improve the accuracy of angular velocity measurement about the Z axis.

[0104] In this embodiment, the first sensor 100, the second sensor 200, and the third sensor 300 in which the sensor elements thereof are hermetically sealed using the lids 10a, 20a, and 30a have been described as an example, but the present invention is not limited to this, and the first sensor 100, the second sensor 200, and the third sensor 300 may not have the lids 10a, 20a, and 30a. This is because the package 2 can hermetically seal the first sensor 100, the second sensor 200, and the third sensor 300 arranged on the base substrate 3.

[0105] 2. Second embodiment Next, an inertial sensor module 1a according to a second embodiment will be described with reference to Fig. 12 and Fig. 13. For ease of description, Fig. 12 omits the illustration of the lid 5 and the lids 10a, 20a, and 30a of the sensors 100, 200, and 300. Figs. 12 and 13 also omit the illustration of the connection terminals formed on the back surface 2b of the package 2 and the wiring formed on the inner bottom surface 2a that electrically connects the connection terminals to the sensors 100, 200, and 300.

[0106] The inertial sensor module 1a of this embodiment is similar to the inertial sensor module 1 of the first embodiment, except that, compared to the inertial sensor module 1 of the first embodiment, a semiconductor chip 70 is housed in the internal space S of the package 2, and a first sensor 100, a second sensor 200, and a third sensor 300 are arranged on the semiconductor chip 70. The following description will focus on the differences from the first embodiment described above, and a description of similar points will be omitted.

[0107] In the inertial sensor module 1a, a semiconductor chip 70 is disposed on the inner bottom surface 2a of the package 2, as shown in FIGS. The semiconductor chip 70 has a first surface 70a and a second surface 70b facing each other, and the first surface 70a of the semiconductor chip 70 is arranged on the inner bottom surface 2a of the package 2, and a first sensor 100, a second sensor 200, and a third sensor 300 are arranged on the second surface 70b, which is coplanar with the semiconductor chip 70.

[0108] Therefore, since the first sensor 100, the second sensor 200, and the third sensor 300 are arranged on the second surface 70b of the semiconductor chip 70, which is one plane within the package 2, an inertial sensor module 1a with excellent axis alignment accuracy can be realized.

[0109] The semiconductor chip 70 includes a drive circuit for driving each of the sensors 100, 200, and 300, a detection circuit for detecting angular velocity around three axes and acceleration in three axial directions based on signals from each of the sensors 100, 200, and 300, and an output circuit for converting signals from the detection circuits into predetermined signals and outputting them.

[0110] With this configuration, it is possible to obtain the same effects as the inertial sensor module 1 of the first embodiment.

[0111] 3. Third embodiment Next, an inertial sensor module 1b according to a third embodiment will be described with reference to Fig. 14 and Fig. 15. For ease of description, Fig. 14 does not show the lid 5. Figs. 14 and 15 also do not show the connection terminals formed on the rear surface 2b of the package 2 and the wiring formed on the inner bottom surface 2a that electrically connects the connection terminals to the sensors 100, 200, and 300.

[0112] The inertial sensor module 1b of this embodiment is similar to the inertial sensor module 1 of the first embodiment except that, compared to the inertial sensor module 1 of the first embodiment, three semiconductor chips 71, 72, and 73 are accommodated in the internal space S of the package 2, with the semiconductor chip 71 being arranged on the first sensor 100, the semiconductor chip 72 being arranged on the second sensor 200, and the semiconductor chip 73 being arranged on the third sensor 300. Note that the following description will focus on the differences from the first embodiment described above, and a description of similar points will be omitted.

[0113] In the inertial sensor module 1b, a first sensor 100, a second sensor 200, and a third sensor 300 are arranged on the inner bottom surface 2a of the package 2, as shown in FIGS. The semiconductor chip 71 is disposed on the cover 10 a of the first sensor 100 . The semiconductor chip 72 is disposed on the cover 20 a of the second sensor 200 . The semiconductor chip 73 is disposed on the cover 30 a of the third sensor 300 .

[0114] Since the three semiconductor chips 71, 72, and 73 are housed within the internal space S of the package 2, the influence of noise on the signals output from the first sensor 100, the second sensor 200, and the third sensor 300 can be reduced, and the inertial sensor module 1b can be made smaller.

[0115] The semiconductor chip 71 includes a drive circuit that drives the first sensor 100, a detection circuit that detects angular velocity around three axes based on signals from the first sensor 100, and an output circuit that converts signals from the detection circuit into predetermined signals and outputs them.

[0116] The semiconductor chip 72 also includes a drive circuit that drives the second sensor 200, a detection circuit that detects the angular velocity around the Z axis based on a signal from the second sensor 200, and an output circuit that converts the signal from the detection circuit into a predetermined signal and outputs it.

[0117] The semiconductor chip 73 also includes a drive circuit that drives the third sensor 300, a detection circuit that detects acceleration in three axes based on a signal from the third sensor 300, and an output circuit that converts the signal from the detection circuit into a predetermined signal and outputs it.

[0118] With this configuration, it is possible to obtain the same effects as the inertial sensor module 1 of the first embodiment.

[0119] 4. Fourth embodiment Next, an inertial sensor module 1c according to a fourth embodiment will be described with reference to Fig. 16 and Fig. 17. For ease of description, Fig. 16 omits the illustration of the lid 5 and the lids 10a, 20a, and 30a of the sensors 100, 200, and 300. Figs. 16 and 17 also omit the illustration of the connection terminals formed on the back surface 2b of the package 2c and the wiring formed on the inner bottom surface 2a that electrically connects the connection terminals to the sensors 100, 200, and 300.

[0120] The inertial sensor module 1c of this embodiment is similar to the inertial sensor module 1 of the first embodiment except that, compared to the inertial sensor module 1 of the first embodiment, three recesses 81, 82, and 83 recessed downward are provided on the inner bottom surface 2a of the base substrate 3c of the package 2c, and a first sensor 100, a second sensor 200, and a third sensor 300 are disposed in the three recesses 81, 82, and 83, respectively. Note that the following description will focus on the differences from the first embodiment described above, and a description of similar points will be omitted.

[0121] As shown in FIGS. 16 and 17, the inertial sensor module 1c has three recesses 81, 82, and 83 recessed downward on the inner bottom surface 2a of the package 2c. The recesses 81, 82, and 83 are each rectangular, with a first sensor 100 being arranged on the inner bottom surface 81a of the recess 81, a second sensor 200 being arranged on the inner bottom surface 82a of the recess 82, and a third sensor 300 being arranged on the inner bottom surface 83a of the recess 83.

[0122] That is, the inertial sensor module 1c has alignment structures provided on inner bottom surfaces 81a, 82a, and 83a, which are planes on which the first sensor 100, the second sensor 200, and the third sensor 300 are arranged. This also improves the X-axis alignment accuracy and Y-axis alignment accuracy between the sensors. In particular, the X-axis alignment accuracy and Y-axis alignment accuracy between the first sensor 100 and the third sensor 300 can be further improved.

[0123] The inner bottom surfaces 81a, 82a, 83a of the recesses 81, 82, 83 are machined to have the same depth, respectively. Therefore, the first sensor 100, the second sensor 200, and the third sensor 300 are arranged on the inner bottom surfaces 81a, 82a, 83a, which are one flat surface within the package 2, thereby realizing an inertial sensor module 1c with excellent axis alignment accuracy.

[0124] With this configuration, it is possible to obtain the same effects as the inertial sensor module 1 of the first embodiment. Furthermore, since the first sensor 100, the second sensor 200, and the third sensor 300 are respectively arranged in recesses 81, 82, and 83 provided on the inner bottom surface 2a of the package 2c, the X-axis alignment accuracy and Y-axis alignment accuracy between each sensor can also be improved. [Explanation of symbols]

[0125] 1, 1a, 1b, 1c... inertial sensor module, 2... package, 2a... inner bottom surface, 2b... back surface, 3... base substrate, 4... recess, 5... lid body, 10, 20, 30... substrate, 10a, 20a, 30a... lid body, 11, 12, 13... recess, 11a, 21a, 31a... recess, 21... convex portion, 31, 32, 33... recess, 100... first sensor, 101... first gyro sensor element, 102... second gyro sensor element, 103... third gyro sensor element, 200... second sensor, 201... vibration gyro sensor element, 300... third sensor, 301... first acceleration sensor element, 302... second acceleration sensor element, 303... third acceleration sensor element, S, S1, S2, S3... internal space.

Claims

1. When three mutually orthogonal axes are defined as the X axis as the first axis, the Y axis as the second axis, and the Z axis as the third axis, a first sensor in which the first axis, the second axis, and the third axis are detection axes, and a first internal space formed by a first substrate and a first lid body accommodates a first gyro sensor element that detects an angular velocity around the X axis, a second gyro sensor element that detects an angular velocity around the Y axis, and a third gyro sensor element that detects an angular velocity around the Z axis; a second sensor having higher accuracy than the first sensor, a detection axis along the third axis, and a gyro sensor element configured to detect an angular velocity around the Z axis housed in a second internal space defined by a second substrate and a second lid; a package having a first plane perpendicular to the Z-axis; the first substrate of the first sensor and the second substrate of the second sensor are disposed on the same first plane; The inertial sensor module, wherein the first sensor and the second sensor are hermetically sealed by the package.

2. the first plane on which the first sensor and the second sensor are arranged is an inner bottom surface of the package; The inertial sensor module of claim 1 .

3. further comprising an alignment structure provided on the first plane on which the first sensor and the second sensor are disposed; The inertial sensor module according to claim 1 or 2.

4. When three mutually orthogonal axes are defined as the X axis as the first axis, the Y axis as the second axis, and the Z axis as the third axis, a first sensor in which the first axis, the second axis, and the third axis are detection axes, and a first internal space formed by a first substrate and a first lid body accommodates a first gyro sensor element that detects an angular velocity around the X axis, a second gyro sensor element that detects an angular velocity around the Y axis, and a third gyro sensor element that detects an angular velocity around the Z axis; a second sensor having higher accuracy than the first sensor, a detection axis along the third axis, and a gyro sensor element configured to detect an angular velocity around the Z axis housed in a second internal space defined by a second substrate and a second lid; The package and a semiconductor chip having a first surface and a second surface facing each other; the first surface of the semiconductor chip is disposed on an inner bottom surface of the package; the second surface of the semiconductor chip is a plane perpendicular to the Z axis, the first substrate of the first sensor and the second substrate of the second sensor are disposed on the second surface of the same semiconductor chip; the first sensor and the second sensor are hermetically sealed by the package. Inertial sensor module.

5. The package is made of ceramic. The inertial sensor module according to any one of claims 1 to 4.

Images