Inertial Sensors

Abstract

To provide an inertial sensor in which electrostatic capacitance variations between a rim of a micro vibration body and a plurality of electrode units of a mounting substrate is reduced.SOLUTION: A micro vibration body 2 is formed of a thin wall member having a front surface 2a of a larger outer diameter and a rear surface 2b and has a curved surface section 21 of a three-dimensional curved surface and a recessed section 22 recessed from the curved surface section 21. In the micro vibration body 2, as a rim 211 of one region including an end portion of the curved surface section 21 opposite to the recessed section 22, a rim lower surface 211c that is a surface connecting the front surface 2a and the rear surface 2b of the rim 211 is positioned on the same plane as a mounting surface 22b that is a bottom surface of the recessed section 22 on a rear surface 2b side. In the micro vibration body 2, the mounting surface 22b is joined to an area surrounded by a frame shape inner frame section 51 of a mounting substrate 3 through a joining member 52, and the rim 211 is in a hollow state.SELECTED DRAWING: Figure 9

Description

[Technical field]

[0001] The present invention relates to an inertial sensor having a micro-vibrator and a method for manufacturing the same. [Background technology]

[0002] In recent years, the development of autonomous driving systems for vehicles has progressed, and this type of system requires highly accurate self-location estimation technology. For example, for so-called Level 3 autonomous driving, development of a self-location estimation system equipped with a GNSS (Global Navigation Satellite System) and an IMU (Inertial Measurement Unit) is underway. The IMU is, for example, a six-axis inertial force sensor consisting of a three-axis gyro sensor and a three-axis acceleration sensor. In order to realize so-called Level 4 or higher autonomous driving in the future, an IMU with even higher sensitivity than the current system will be required.

[0003] As a gyro sensor for realizing such a highly sensitive IMU, for example, BRG (short for Bird-bath Resonator Gyroscope) is considered to be a promising candidate. BRG is configured by mounting a micro-vibrator with a three-dimensional curved surface that vibrates in wine glass mode on a mounting board (for example, Patent Document 1). This micro-vibrator has a Q value that represents the vibration state of 10 6 This is expected to result in higher sensitivity than before. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] US Patent Application Publication No. 2019 / 0094024 Summary of the Invention [Problem to be solved by the invention]

[0005] As described in Patent Document 1, for example, this micro-vibrator is formed by setting a plate material such as quartz that can be subjected to a reflow process by heating in a mold, melting it, and solidifying it to form a three-dimensional curved surface that vibrates in a wine glass mode. After covering the plate material after the above processing with a sealing material, this micro-vibrator has a structure having a mounting part that is bonded to a mounting board and a three-dimensional shape part that becomes hollow when mounted on the mounting board by removing unnecessary parts by polishing or CMP (short for Chemical Mechanical Polishing). In addition, this micro-vibrator has electrode films that cover the front and back surfaces, and is disposed at a distance from multiple electrode parts formed on the mounting board on which it is mounted, forming a capacitor with them.

[0006] The BRG described in Patent Document 1 has a micro-vibrator (BR) that serves as a resonator mounted on a mounting board having a plurality of electrode parts arranged in a ring shape at a distance from each other, and the rim of the BR is hollow. However, when this BRG is manufactured, the mounting portion of the micro-vibrator may be inclined with respect to the mounting surface of the mounting board, and the micro-vibrator may be joined in an inclined state with respect to the mounting board. In this case, the area of ​​the rim of the micro-vibrator that is arranged to face the plurality of electrode parts varies depending on the location. As a result, the electrostatic capacitance of each capacitor formed by the BR and the plurality of electrode parts varies in the BRG, reducing the sensor accuracy.

[0007] In view of the above, an object of the present invention is to provide an inertial sensor in which a micro-vibrator that vibrates in a wine glass mode is mounted on a mounting substrate, by suppressing variation in the area of ​​the rim of the micro-vibrator that is arranged opposite multiple electrode portions of the mounting substrate, thereby improving sensor accuracy. [Means for solving the problem]

[0008] In order to achieve the above object, claim 1 or 3 The inertial sensor described in is an inertial sensor, which is a thin-walled member having a front surface (2a) that is a surface on the side with a larger outer diameter and a back surface (2b) that is the opposite surface to the front surface, and has a curved surface portion (21) having an annular curved surface and a recessed portion (22) recessed from the curved surface portion to the back surface side. Cylindrical with bottomThe micro-vibrator (2) has a recess (22), a mounting board (3) formed by joining an upper substrate (5) having a frame-shaped inner frame portion (51) and a plurality of electrode portions (53) arranged at a distance from each other and surrounding the inner frame portion to a lower substrate (4), and a bonding member (52) arranged in an inner region of the mounting board surrounded by the inner frame portion, wherein the micro-vibrator has a mounting surface (22b) which is the bottom surface of the back surface side of the recess, which is arranged in the inner region and bonded to the mounting board via the bonding member, a rim (211) which is a partial region of the curved portion including the end portion opposite the recess, which is hollow, and a rim underside (211c) which is the surface of the rim connecting the front surface and the back surface, which is located on the same plane as the mounting surface or the tip portion (28). In the inertial sensor described in claim 1, the micro-vibrator has, on its mounting surface, a mounting surface recess (26) recessed from the back surface toward the front surface, and a protrusion (27) protruding from the mounting surface recess toward the mounting surface, and the mounting board has a positioning groove (43) corresponding to the protrusion, and the protrusion is inserted into the positioning groove. In the inertial sensor described in claim 2, the micro-vibrator is provided on a side surface of the recess near the bottom surface of the front surface, and has a side through-hole (24) connecting the front surface and the back surface, and at least a portion of the joining member fits into the side through-hole. In the inertial sensor described in claim 3, the micro-vibrator has a bottom surface through-hole (25) provided on the mounting surface, and at least a part of the bonding member fits into the bottom surface through-hole.

[0009] According to this, the micro-vibrator having a curved surface portion having a three-dimensional curved surface and a recess recessed from the curved surface portion is bonded to a mounting substrate, and the rim, which is a region including the end of the curved surface portion opposite to the recess, is in a hollow state. In this inertial sensor, the mounting surface of the micro-vibrator bonded to the mounting substrate in the recess or its tip portion and the rim lower surface connecting the front surface and back surface of the rim are located on the same plane. Therefore, even when the micro-vibrator is tilted with respect to the mounting substrate, the mounting surface and the rim lower surface are located at the same height, so that the positional variation in the height direction of the rim with respect to the multiple electrodes of the mounting substrate, that is, the area variation of the rim arranged opposite to the mounting substrate, is reduced. Therefore, in this inertial sensor, even when the micro-vibrator is tilted with respect to the mounting substrate, the capacitance variation of the capacitor formed by the micro-vibrator and the multiple electrodes of the mounting substrate is suppressed, and the sensor accuracy is improved.

[0010] Claim 6 The method for manufacturing an inertial sensor described in the above is a method for manufacturing an inertial sensor comprising: a thin-walled member having a front surface (2a) that is a surface on the side with a larger outer diameter and a back surface (2b) that is the opposite surface to the front surface; a curved surface portion (21) having an annular curved surface; and a recessed portion (22) recessed from the curved surface portion to the back surface side. Cylindrical with bottomA method for manufacturing an inertial sensor in which a micro-vibrator (2) having a recess (22), an upper substrate (5) having a frame-shaped inner frame portion (51) and a plurality of electrode portions (53) arranged to surround the inner frame portion while being spaced apart from each other, and a mounting substrate (3) formed by joining the upper substrate (5) to a lower substrate (4) via a joining member (52) includes the steps of: preparing a micro-vibrator; arranging the joining member in an inner region of the mounting substrate surrounded by the inner frame portion; after arranging the joining member, arranging the recess of the micro-vibrator in the inner region, bringing the mounting surface (22b), which is the bottom surface of the recess on the back side, into contact with the joining member; and melting the joining member. and then solidifying the micro-vibrator to bond the micro-vibrator to the mounting board, and making a rim (211) that is the end of the curved portion of the micro-vibrator opposite the recessed portion into a hollow state. In preparing the micro-vibrator, a thin-walled base material (20) on the order of micrometers is heated and melted, and solidified to form a curved portion (201) that will later become the curved portion, and a recessed portion (202) that will later become the recessed portion, and then the thin-walled base material is sealed with a sealing material (E), and the curved portion, the recessed portion, and a part of the sealing material are removed by polishing to form a mounting surface and a rim underside (211c) that connects the front and back surfaces of the rim, which are located on the same plane. In addition, a through hole (24, 25) is formed on the mounting surface or in the vicinity of the mounting surface, and in making the rim hollow, a part of the molten joining material is poured into the through hole. .

[0011] According to this, the method for manufacturing an inertial sensor includes heating and melting a thin-walled substrate, solidifying it to form curved portions and recessed portions, and polishing it to form a micro-oscillator having a mounting surface and a rim underside located on the same plane. Since the mounting surface and the rim underside of the micro-oscillator are located on the same plane, even if the micro-oscillator is tilted when bonding the micro-oscillator to the mounting board, the area variation of the rim located opposite the multiple electrodes of the mounting board is reduced. Therefore, the capacitance variation of the capacitor formed by the micro-oscillator and the multiple electrodes of the mounting board is suppressed, and an inertial sensor with improved sensor accuracy can be manufactured.

[0012] Claim 7The method for manufacturing an inertial sensor described in the above is a method for manufacturing an inertial sensor comprising: a thin-walled member having a front surface (2a) that is a surface on the side with a larger outer diameter and a back surface (2b) that is the opposite surface to the front surface; a curved surface portion (21) having an annular curved surface; and a recessed portion (22) recessed from the curved surface portion to the back surface side. Cylindrical with bottom A method for manufacturing an inertial sensor in which a micro-vibrator (2) having a recess (22) and a through-hole (25) formed in a mounting surface (22b) which is the bottom surface of the recess, and a mounting board (3) formed by bonding an upper substrate (5) having a frame-shaped inner frame portion (51), a plurality of electrode portions (53) arranged to surround the inner frame portion while being spaced apart from each other, and a support portion (55) arranged in an area surrounded by the inner frame portion to a lower substrate (4) via a bonding member (52) includes the steps of: preparing a micro-vibrator; inserting the support portion of the mounting board into the through-hole of the micro-vibrator, and placing the micro-vibrator on the mounting board; and, after placing the micro-vibrator on the mounting board, bonding the micro-vibrator to the recess. The process includes pouring a material into the micro-vibrator and solidifying it to bond the micro-vibrator to the mounting board, and making a rim (211), which is the end of the curved portion of the micro-vibrator opposite the recess, hollow. In preparing the micro-vibrator, a thin-walled base material (20) on the order of micrometers is heated, melted, and solidified to form a curved portion (201) that will later become the curved portion, and a recessed portion (202) that will later become the recess, and then sealing the thin-walled base material with a sealing material (E) and polishing away the curved portion, the recessed portion, and part of the sealing material to form the mounting surface and the rim underside (211c) that connects the front and back surfaces of the rim, which are located on the same plane.

[0013] According to this, as in the manufacturing method of the inertial sensor according to claim 7, in addition to the mounting surface and the lower surface of the rim being located on the same plane, a micro-vibrator having a through hole is formed on the mounting surface. Meanwhile, a mounting substrate having a support part to be inserted into the through hole formed on the mounting surface of the micro-vibrator is prepared. Then, after inserting and placing the support part of the mounting substrate into the through hole of the micro-vibrator, a bonding material is poured into the recess of the micro-vibrator and solidified to bond the micro-vibrator to the mounting substrate. Even after such a bonding process, since the mounting surface and the lower surface of the rim are located on the same plane, the variation in the electrostatic capacitance of the capacitor formed by the micro-vibrator and the multiple electrodes of the mounting substrate is suppressed, and an inertial sensor with improved sensor accuracy can be manufactured.

[0014] The reference symbols in parentheses attached to each component indicate an example of the correspondence between the component and specific components described in the embodiments described below. [Brief description of the drawings]

[0015] [Figure 1] FIG. 2 is a top view layout diagram showing the inertial sensor according to the first embodiment. [Diagram 2] FIG. 2 is a perspective view showing a micro-vibrator used in the inertial sensor. [Diagram 3] 3 is a cross-sectional view showing a cross-sectional configuration taken along line III-III in FIG. 2. [Figure 4A] 11A to 11C are diagrams showing a process of preparing a member in a process of forming a micro-vibrator. [Figure 4B] FIG. 4B is a diagram showing a step following FIG. 4A. [Figure 4C] FIG. 4B shows a step following FIG. 4B. [Figure 4D] FIG. 4B is a diagram showing a step following FIG. 4C. [Diagram 5] 3 is a top view layout diagram showing a mounting substrate on which the microvibrator of FIG. 2 is mounted. [Figure 6] 6 is a cross-sectional view showing a cross-sectional configuration taken along line VI-VI in FIG. 5. [Figure 7] 7 is a cross-sectional view showing a cross-sectional configuration taken along line VII-VII in FIG. 5. [Figure 8] FIG. 2 is a cross-sectional view showing a cross-sectional configuration taken along line VIII-VIII in FIG. [Figure 9] FIG. 2 is a cross-sectional view showing a cross-sectional configuration taken along line IX-IX in FIG. [Figure 10A] FIG. 11 is a cross-sectional view showing a micro-vibration body of a comparative example. [Figure 10B] 10B is a cross section showing a cross-sectional configuration of an inertial sensor of a comparative example in which the micro-vibrator of FIG. 10A is mounted on a mounting substrate. [Figure 11A] 10A to 10C are diagrams showing a step of mounting a micro-vibrator in the manufacture of an inertial sensor, and are diagrams showing a step of preparing a member. [Figure 11B] FIG. 11B is a diagram showing a step following FIG. 11A. [Figure 11C] FIG. 11B shows a step following FIG. [Figure 11D] FIG. 11B is a diagram showing a step following FIG. 11C. [Figure 11E] FIG. 11B shows a step following FIG. 11D. [Figure 12] FIG. 4 is a cross-sectional view showing a modified example of the micro-vibrator of the inertial sensor of the first embodiment. [Figure 13] FIG. 4 is a cross-sectional view showing a modified example of the inertial sensor of the first embodiment. [Figure 14] FIG. 11 is a cross-sectional view showing an inertial sensor according to a second embodiment. [Figure 15] FIG. 11 is a cross-sectional view showing a micro-vibrator in an inertial sensor according to a second embodiment. [Figure 16] FIG. 11 is a cross-sectional view showing an inertial sensor according to a third embodiment. [Figure 17] FIG. 11 is a cross-sectional view showing a micro-vibrator in an inertial sensor according to a third embodiment. [Figure 18] 13 is an explanatory view for explaining an example of a method for forming a bottom surface through-hole in the third embodiment. FIG. [Figure 19] FIG. 13 is a top view layout diagram showing a modified example of the inertial sensor of the third embodiment. [Figure 20] FIG. 13 is a top view layout diagram showing a mounting board according to a modified example of the inertial sensor of the third embodiment. [Figure 21]FIG. 20 is a cross-sectional view showing a cross-sectional configuration taken along line XXI-XXI in FIG. 19. [Figure 22] FIG. 11 is a cross-sectional view showing an inertial sensor according to a fourth embodiment. [Diagram 23] FIG. 13 is a cross-sectional view showing a micro-vibrator in an inertial sensor according to a fourth embodiment. [Figure 24] FIG. 13 is a top view layout diagram showing a mounting board for the inertial sensor according to the fourth embodiment. [Figure 25A] 23 is a diagram showing a member preparation step in the molding process of the micro-vibration body shown in FIG. 22. [Figure 25B] FIG. 24B is a diagram showing a step following FIG. 24A. [Figure 26] FIG. 13 is a cross-sectional view showing a micro-vibrator according to a modified example of the inertial sensor of the fourth embodiment. [Figure 27] FIG. 13 is a top view layout diagram showing a mounting board according to a modified example of the inertial sensor of the fourth embodiment. [Figure 28] FIG. 13 is a cross-sectional view showing a modified example of the inertial sensor of the fourth embodiment. [Figure 29] FIG. 13 is a cross-sectional view showing another modified example of the inertial sensor of the fourth embodiment. [Diagram 30] FIG. 30 is a diagram showing a step of mounting a micro-vibrator in the manufacture of the inertial sensor of FIG. 29, and is an explanatory diagram for explaining a step of placing the micro-vibrator on a mounting substrate and a subsequent step of filling with a bonding material. [Diagram 31] 11A and 11B are cross-sectional views showing other examples of the shape of the micro-vibrator. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, parts that are the same or equivalent to each other will be denoted by the same reference numerals.

[0017] (First embodiment) An inertial sensor 1 according to an embodiment will be described with reference to FIGS.

[0018] In FIG. 2, in order to make it easier to understand the configuration of the micro-vibration body 2, which will be described later, a cross section is shown with a portion of the micro-vibration body 2 omitted, and the portion of the outer periphery of the micro-vibration body 2 that cannot be seen from the angle shown in FIG. 2 is shown by dashed lines.

[0019] For the sake of convenience, the direction along the left-right direction on the paper as shown in FIG. 1 is referred to as the "x direction", the direction perpendicular to the x direction on the paper as the "y direction", and the normal direction to the xy plane as the "z direction". The x, y, and z directions in FIG. 3 and subsequent figures correspond to the x, y, and z directions in FIG. 1, respectively. In addition, in this specification, "upper" refers to the direction along the z direction in the figure, and means the side indicated by the arrow, and "lower" refers to the opposite side to the upper side. In addition, in this specification, the state in which the inertial sensor 1 or the mounting board 3 is viewed from above in the z direction, as shown in FIG. 1, for example, may be referred to as "top view".

[0020] [Basic configuration] 1, the inertial sensor 1 includes a micro-vibrator 2 and a mounting substrate 3, and a part of the micro-vibrator 2 is joined to the mounting substrate 3. The inertial sensor 1 is configured to detect an angular velocity applied to the inertial sensor 1 based on a change in electrostatic capacitance between the thin-walled micro-vibrator 2 capable of vibrating in a wine glass mode and a plurality of electrode parts 53 (described later) of the mounting substrate 3. The inertial sensor 1 is, for example, a gyro sensor with a BRG structure, and is suitable for use in applications in which it is mounted on a vehicle such as an automobile, but can of course also be used for other applications.

[0021] 1 and 2, the micro-vibration body 2 has a curved surface portion 21 having an outer shape of a three-dimensional curved surface of a substantially hemisphere, and a recessed portion 22 recessed from the apex side of the substantially hemisphere curved surface portion 21 toward the center of the hemisphere. The micro-vibration body 2 has a rim 211, which is the end of the curved surface portion 21 opposite to the recessed portion 22, having a substantially cylindrical shape. For example, the curved surface portion 21 of the micro-vibration body 2 has a three-dimensional curved surface in a bowl shape, and the Q value of the vibration is 10 6The end of the curved portion 21 opposite to the recessed portion 22 is the rim 211, and when the micro-vibrator 2 is mounted on the mounting substrate 3, for example, the front surface 2a of the rim 211 faces a plurality of electrode portions 53 (described later) of the mounting substrate 3, and the plurality of electrode portions 53 are spaced at equal intervals.

[0022] 3, the micro-vibrator 2 has a surface with a larger outer diameter as the front surface 2a and a back surface 2b on the opposite side, and the bottom surface of the recess 22 in the Z direction on the back surface 2b side serves as a mounting surface 22b to be bonded to the mounting substrate 3. For example, the bottom surface of the recess 22 in the Z direction on the front surface 2a side serves as an adsorption surface 22a used for transportation when mounting the micro-vibrator 2 on the mounting substrate 3. When mounted on the mounting substrate 3, the micro-vibrator 2 has a structure in which the curved surface portion 21 including the rim 211 is in a hollow state in which it does not come into contact with other members, and the hollow rim 211 vibrates in a wine glass mode.

[0023] As shown in FIG. 3, the micro-oscillating body 2 has a shape in which the surface of the rim 211 connecting the front surface 2a and the back surface 2b is the rim undersurface 211c, and the rim undersurface 211c and the mounting surface 22b form the same imaginary plane 22b1. This is a result of simultaneously forming the rim undersurface 211c and the mounting surface 22b by polishing and CMP in a forming process of the micro-oscillating body 2 described later. Since the rim undersurface 211c and the mounting surface 22b of the micro-oscillating body 2 are in the same plane, when the micro-oscillating body 2 is mounted on the mounting board 3, the positional variation in the height direction of the rim 211 with respect to the multiple electrode parts 53 of the mounting board 3 is reduced. In other words, the micro-oscillating body 2 has a shape in which the area variation of the rim 211 arranged opposite the multiple electrode parts 53 is reduced when mounted on the mounting board 3. For example, the entire front surface 2a and the back surface 2b of the micro-oscillating body 2 are covered with the conductive layer 23.

[0024] The conductive layer 23 is, for example, but not limited to, made of a laminated film of Cr (chromium) or Ti (titanium) and any conductive material such as Au (gold) or Pt (platinum) from the base side, and functions as an electrode film. The conductive layer 23 is formed on the front surface 2a and the back surface 2b of the micro-vibration body 2 by any vacuum film forming method such as sputtering or vapor deposition.

[0025] The micro-vibrator 2 is made of, for example, quartz, glass, silicon, ceramic, or other materials, but is not limited to these materials as long as it can form the curved surface portion 21 and the recessed portion 22 in a three-dimensional curved shape and can vibrate in wine glass mode. The micro-vibrator 2 is formed, for example, by processing a thin-walled base material made of the above-mentioned materials in a forming process described later, so that the curved surface portion 21 and the recessed portion 22 are thin members on the order of micrometers, such as 20 μm to 80 μm in thickness. The micro-vibrator 2 has, for example, a millimeter-sized shape with a height dimension of 2.5 mm and an outer diameter of the rim 211 on the surface 2a side of 5 mm, with the height direction being the direction along the thickness direction of the mounting substrate 3.

[0026] The micro-vibrator 2 is formed, for example, by the following process.

[0027] First, as shown in FIG. 4A, for example, a quartz plate 20, a mold M for forming a three-dimensional curved shape, and a cooling body C for cooling the mold M are prepared. The mold M includes, for example, a recess M1 that serves as a space when forming a three-dimensional curved shape on the quartz plate 20, and a columnar support M2 that extends along the depth direction of the recess M1 at the center of the recess M1 and supports a part of the quartz plate 20 during processing. The mold M has a through hole M11 formed in the bottom surface of the recess M1, and is attached to the cooling body C so that the through hole M11 communicates with the cooling body C. The cooling body C includes an insertion portion C1 into which the mold M is inserted, and an exhaust port C11 for exhaust on the bottom surface of the insertion portion C1, and plays a role of cooling the mold M when processing the quartz plate 20. The quartz plate 20 is arranged so as to cover the entire area of ​​the recess M1 of the mold M.

[0028] Next, as shown in FIG. 4B, for example, a flame F is blown from a torch T toward the quartz plate 20 to heat and melt the quartz plate 20. At this time, the recess M1 of the mold M is evacuated through an exhaust port C11 of the cooling body C by a vacuum mechanism (not shown). As a result, the molten part of the quartz plate 20 is stretched toward the bottom surface of the recess M1, and the central peripheral area is supported by the support part M2. After that, by stopping the heating of the quartz plate 20 and cooling it, the quartz plate 20 is formed with a curved surface part 201 having a substantially hemispherical three-dimensional curved shape, and a recessed part 202 recessed near the center of the curved surface part 201 by being supported by the support part M2. In addition, the part of the quartz plate 20 located outside the recess M1 is located at the outer peripheral end of the curved surface part 201, and becomes an end part 203 having a flat shape.

[0029] Next, the depression M1 of the mold M is returned to normal pressure, the processed quartz plate 20 is removed, and the quartz plate 20 is sealed with a sealing material E made of any curable resin material, for example, as shown in Fig. 4C. Thereafter, for example, as shown in Fig. 4D, the sealing material E is polished and CMP (short for Chemical Mechanical Polishing) is performed from the surface close to the end 203, and the end 203 and the tip portion of the recessed portion 202 are removed together with the sealing material E. As a result, the quartz plate 20 has a curved surface portion 21 with an annular curved surface and a recessed portion 22 recessed from the curved surface portion 21, and the rim lower surface 211c and the mounting surface 22b are shaped to be located on the same plane.

[0030] Then, the sealing material E is entirely removed by any method such as heating or dissolving using a chemical solution, and the quartz plate 20 is taken out. Finally, a conductive layer 23 is formed on the front and back surfaces of the quartz plate 20 after the above processing by any film formation process such as sputtering, vapor deposition, atomic layer deposition (ALD), or chemical vapor deposition (CVD).

[0031] The micro-vibration body 2 is manufactured by the above-mentioned manufacturing process, for example, and has a rotationally symmetrical approximately half-toroidal shape with the Z direction as the rotation axis, but the molding of the base material is not limited to the above-mentioned method, and other known methods may be adopted. Also, the micro-vibration body 2 may have any shape as long as it can vibrate in the wine glass mode, and is not limited to the BR shape.

[0032] 5, the mounting substrate 3 includes a lower substrate 4 and an upper substrate 5 which are bonded together. For example, the mounting substrate 3 is obtained by anodically bonding the upper substrate 5 made of a semiconductor material, Si (silicon), to the lower substrate 4 made of an insulating material, borosilicate glass. The mounting substrate 3 includes an inner frame portion 51, a plurality of electrode portions 53 arranged at a distance from each other so as to surround the inner frame portion 51, and an outer frame portion 54 arranged so as to surround the electrode portions 53.

[0033] The inner frame portion 51 has, for example, a circular ring shape in top view, but is not limited to this shape as long as it is a frame shape that surrounds the area of ​​the lower substrate 4 to which the micro-vibrator 2 is bonded. As shown in Fig. 8 and Fig. 9, for example, the outer diameter and inner diameter of the inner frame portion 51 are sized so as not to abut against the micro-vibrator 2, which has a substantially M-shape in cross section.

[0034] The electrode portions 53 are spaced apart from one another and are positioned on the outer periphery of the etching grooves 41 so as to surround the inner frame portion 51. As shown in Fig. 5, the electrode portions 53 have arc-shaped inner and outer periphery sides when viewed from above, and when the inner and outer periphery sides are connected, they form intermittent circles with different diameters. In other words, the electrode portions 53 are configured by equally dividing a ring surrounding the inner frame portion 51 at a predetermined interval.

[0035] As shown in FIG. 6, the electrode portions 53 each have an electrode film 531 formed on the upper surface. The electrode portions 53 can be electrically connected to an external circuit board or the like (not shown) by connecting wires (not shown) to the electrode film 531. When the micro-vibrator 2 is mounted, each of the electrode portions 53 is spaced a predetermined distance from the rim 211 of the micro-vibrator 2 as shown in FIG. 1 or FIG. 8, and each of the electrode portions 53 forms a capacitor with the micro-vibrator 2. That is, the mounting substrate 3 can detect the electrostatic capacitance between the micro-vibrator 2 and the mounting substrate 3 through the electrode portions 53, generate electrostatic attraction between the micro-vibrator 2 and the mounting substrate 3, and vibrate the micro-vibrator 2 in a wine glass mode.

[0036] The "inner circumference side" of the mounting substrate 3 means the center side of the inner region surrounded by the inner frame portion 51 in the top view as shown in Fig. 5, and the "outer circumference side" means the side located opposite to the inner circumference side. Also, Fig. 1 and other figures show an example in which 16 electrode portions 53 are evenly arranged on the mounting substrate 3 so as to form a ring apart from each other, but this is not limiting, and the number and arrangement of the electrode portions 53 can be changed as appropriate depending on the shape, size, etc. of the micro-vibration body 2.

[0037] The outer frame portion 54 has a frame shape surrounding the inner frame portion 51 when viewed from above, and is provided with an electrode film 541 made of Al or the like on its upper surface, as shown in Figures 5 and 7, for example. The outer frame portion 54 has wires (not shown) connected to the electrode film 541, and is electrically connected to an external circuit board (not shown) or the like, so that the potential of the outer frame portion 54 can be controlled by an external power source (not shown) or the like.

[0038] In the mounting substrate 3, an annular etching groove 41 is formed surrounding the inner frame portion 51 at a position on the outer periphery side of the annular inner frame portion 51 when viewed from above. As a result, when the micro-vibrator 2 is mounted on the mounting substrate 3, the curved surface portion 21 including the rim 211 of the micro-vibrator 2 becomes hollow, for example, as shown in Figs. 8 and 9.

[0039] As shown in FIG. 5, the mounting substrate 3 includes a bridge wiring 42 that connects the inner frame portion 51 and the outer frame portion 54 while straddling the etching groove 41 of the lower substrate 4 in a top view. The bridge wiring 42 is made of a conductive material such as Al (aluminum) and is disposed so as to pass between the plurality of electrode portions 53 and is electrically independent from the plurality of electrode portions 53. As shown in FIG. 7, one end of the bridge wiring 42 is covered by the outer frame portion 54 and the other end on the opposite side is covered by the inner frame portion 51. As a result, the bridge wiring 42 electrically connects the inner frame portion 51 and the outer frame portion 54 and serves to make them at the same potential. In addition, a bonding member 52 is disposed in the inner region of the mounting substrate 3 surrounded by the inner frame portion 51, and the micro-vibrator 2 is bonded thereto, so that the outer frame portion 54 is electrically connected to the micro-vibrator 2 via the bridge wiring 42, the inner frame portion 51, and the bonding member 52. In other words, the mounting substrate 3 is capable of adjusting the potential of the micro-vibrator 2 by adjusting the potential of the outer frame portion 54. Note that the number and arrangement of the bridge wirings 42 are not limited to the example shown in FIG. 5 and can be changed as appropriate.

[0040] The mounting board 3 can be manufactured, for example, by the following process.

[0041] First, a lower substrate 4 made of, for example, borosilicate glass is prepared, and an annular etching groove 41 is formed by wet etching using buffered hydrofluoric acid. Then, a bridge wiring 42 spanning the etching groove 41 is formed by a lift-off method using, for example, Al sputtering to form a film. The thickness of the bridge wiring 42 is, for example, about 0.1 μm.

[0042] Next, for example, a Si substrate (later upper substrate 5) made of Si is prepared and anodically bonded to the borosilicate glass lower substrate 4. Next, grooves that partition the regions that will later become the inner frame portion 51, the plurality of electrode portions 53, and the outer frame portion 54 are formed in the Si substrate by a known etching method.

[0043] Specifically, for example, trench etching is performed by DRIE (abbreviation of Deep Reactive Ion Etching) to expose the lower substrate 4 and separate the inner frame portion 51, the multiple electrode portions 53, and the outer frame portion 54. As a result, the Si substrate becomes the upper substrate 5 including the inner frame portion 51, the multiple electrode portions 53, and the outer frame portion 54, which are separated from one another. Also, the etching grooves 41 formed in the lower substrate 4 are exposed from the upper substrate 5 by this partitioning process of the Si substrate.

[0044] Finally, electrode films 531, 541 are formed on the upper surfaces of the plurality of electrode portions 53 and the outer frame portion 54 by sputtering or the like. As a result of these steps, the mounting substrate 3 having the above-described structure is obtained. When the micro-vibrator 2 is mounted on the mounting substrate 3, the bonding member 52 is disposed in the positioning groove 43 of the lower substrate 4. The bonding member 52 is a paste-like conductive material made of a conductive material such as AuSn (gold tin), Ag (silver), or Au, and is applied to the inner region surrounded by the inner frame portion 51.

[0045] 5 and the like can be obtained, for example, by forming areas on a wafer that will become a plurality of mounting substrates 3 having the above-described structure, and then dividing the wafer into individual pieces by dicing, etc. In other words, the mounting substrate 3 can be manufactured at the wafer level.

[0046] Furthermore, for example, in a vacuum environment with a predetermined degree of vacuum or less, the mounting substrate 3 is attached such that a cap member (not shown) does not come into contact with the micro-vibrator 2, and the micro-vibrator 2 is vacuum-tightly sealed.

[0047] The above is the basic configuration of the inertial sensor 1. When the inertial sensor 1 is driven, it generates an electrostatic attractive force between some of the multiple electrode parts 53 and the micro-vibrator 2, thereby vibrating the micro-vibrator 2 in a wine glass mode. When an external Coriolis force is applied to the inertial sensor 1 while the micro-vibrator 2 is in a vibrating state, the micro-vibrator 2 is displaced and the position of the node of the vibration mode changes. The inertial sensor 1 detects the change in the node of this vibration mode by the electrostatic capacitance between the micro-vibrator 2 and the multiple electrode parts 53, thereby making it possible to detect the angular velocity acting on the inertial sensor 1.

[0048] This inertial sensor 1 has a micro-vibrator 2 shaped so that the mounting surface 22b and the rim underside 211c are located on the same plane, and is joined to a mounting substrate 3, thereby reducing the variation in capacitance of each capacitor formed by the rim 211 and the multiple electrode portions 53.

[0049] Here, the above-mentioned effects due to the shape of the micro-vibration body 2 will be described in comparison with, for example, the micro-vibration body 6 of a comparative example shown in FIG. 10A.

[0050] The micro-vibration body 6 of the comparative example has a curved surface portion 61 of a substantially hemispherical shape, a recessed portion 62 recessed from the apex of the substantially hemispherical curved surface portion 61 toward its center, and an electrode film 63 covering these, and has a shape in which a rim lower surface 611c of the rim 611 protrudes downward in the z direction from a bottom surface 62b of the recessed portion 62. The micro-vibration body 6 of the comparative example is formed, for example, in the same manner as the micro-vibration body 2 according to the present embodiment, by performing the process shown in FIG. 4A to FIG. 4C and then stopping the process of removing unnecessary parts at a stage before the bottom surface 62b of the recessed portion 62 is reached. Therefore, the micro-vibration body 6 of the comparative example has a shape in which the rim lower surface 611c is located on the same plane as the bottom surface 62b of the recessed portion 62, as shown by the dashed line, and is located on a different plane from the bottom surface 62b of the recessed portion 62.

[0051] In the above-described process of removing unnecessary portions, when the grinding surface is tilted relative to the bottom surface 62b of the recess 62, the rim 611 will have a shape in which the degree of protrusion relative to the bottom surface 62b differs between the left and right sides in cross-sectional view, as in the comparative example micro-vibration body 6. The inertial sensor obtained by mounting this comparative example micro-vibration body 6 on the mounting substrate 3 and having the comparative example micro-vibration body 6 tilted relative to the mounting substrate 3 is referred to as the "comparative example inertial sensor 100."

[0052] Specifically, in the inertial sensor 100 of the comparative example, as shown in FIG. 10B, the micro-vibrator 6 of the comparative example is tilted, and the area of ​​the rim 611 arranged to face each of the multiple electrode parts 53 of the mounting substrate 3 is greatly different. For example, in the micro-vibrator 6 of the comparative example, a distribution occurs in the height position of the rim lower surface 611c in the z direction, and there are parts where the rim 611 faces only a part of the side surface of the electrode part 53 along the z direction, and parts where the rim 611 faces the entire side surface of the electrode part 53. In this case, the electrode part 53 whose entire side surface faces the rim 611 and the electrode film 63 covering it has a larger capacitance than the other electrode part 53 whose only a part of the side surface faces the rim 611 and the electrode film 63 covering it. In other words, the inertial sensor 100 of the comparative example has a configuration in which the capacitance varies greatly for each of the multiple electrode parts 53, and the sensor accuracy decreases.

[0053] In contrast, the inertial sensor 1 of this embodiment is configured using a micro-vibrator 2 in which the mounting surface 22b and the rim underside 211c are located on the same plane, so even if the micro-vibrator 2 is tilted, the area variation of the rim 211 arranged opposite the electrode portion 53 is reduced. As a result, the inertial sensor 1 has reduced capacitance variation of each capacitor configured by the rim 211 and the multiple electrode portions 53 compared to the inertial sensor 100 of the comparative example, and an effect of improving sensor accuracy is obtained.

[0054] Fig. 10A is a cross-sectional view showing a cross section corresponding to Fig. 3. Fig. 10B is a cross-sectional view showing a cross section corresponding to Fig. 9.

[0055] [Inertial sensor manufacturing method] Next, a manufacturing method for the inertial sensor 1 of this embodiment will be described with reference to Figures 11A to 11E. However, since the manufacture of the micro-vibrator 2 and the mounting substrate 3 themselves has been described above, the process of bonding the micro-vibrator 2 to the mounting substrate 3 will be mainly described here.

[0056] 11A to 11E correspond to the cross-sectional view shown in Fig. 9. In Fig. 11C to 11E, for ease of viewing, only a part of pickup mechanism 300, which will be described later, is shown in a simplified manner, and the inside of collet 302 is shown by a dashed line. In Fig. 11D and 11E, for ease of understanding, the movement direction of pickup mechanism 300 is shown by a hollow arrow.

[0057] First, as shown in Fig. 11A, for example, a micro-vibrator 2 and a mounting substrate 3 manufactured by the above-mentioned method are prepared. Then, for example, as shown in Fig. 11B, a bonding member 52 is disposed in an inner region surrounded by an inner frame portion 51. For example, a conductive bonding material such as Au paste or Ag paste is used as the bonding member 52, and the bonding member 52 is disposed by application using a syringe or the like.

[0058] Then, for example, the mounting board 3 is placed on an adsorption surface of a mounter device (not shown) and fixed by vacuum adsorption. Note that this mounter device (not shown) is configured to include a heating mechanism capable of heating the adsorption surface.

[0059] Next, as shown in FIG. 11C, for example, a part of the pickup mechanism 300 is inserted into the suction surface 22a, which is the bottom of the recess 22 of the micro-oscillating body 2 on the surface 2a side, and the micro-oscillating body 2 is gripped by vacuum suction. The pickup mechanism 300 includes, for example, a base 301 and a collet 302 having a substantially cylindrical shape, and the base 301 is connected to a transport unit and a vacuum mechanism (not shown), and is configured to be capable of vacuum suction by the collet 302 and transport of the object that has been sucked up. For example, the maximum diameter of the collet 302 is smaller than the inner diameter of the recess 22, and the outer diameter of the tip of the collet 302 is smaller than the other parts. Moreover, the pickup mechanism 300 is configured such that the length of the collet 302 is greater than the depth of the recess 22 of the micro-oscillating body 2, and when the collet 302 is inserted into the recess 22 of the micro-oscillating body 2, the collet 302 does not come into contact with any part other than the suction surface 22a of the micro-oscillating body 2. This prevents the conductive layer 23 and base material of the micro-vibrator 2 from being damaged when the micro-vibrator 2 is transported.

[0060] On the other hand, the mounting substrate 3 is heated while being sucked by a mounter device (not shown) to melt or soften the bonding member 52. Then, for example as shown in FIG. 11D, the above-mentioned pickup mechanism 300 is used to hold the suction surface 22a of the micro-vibrator 2 by vacuum suction while the mounting surface 22b of the recess 22 of the micro-vibrator 2 is inserted inside the inner frame portion 51 of the mounting substrate 3. Then, the micro-vibrator 2 is brought closer to the mounting substrate 3, and the mounting surface 22b of the micro-vibrator 2 is brought into contact with the bonding member 52.

[0061] The alignment of the micro-vibrator 2 with respect to the mounting substrate 3 can be performed, for example, by imaging the micro-vibrator 2 and the mounting substrate 3 and extracting feature points by edge detection using a known image processing technique, thereby adjusting the relative position.

[0062] Thereafter, the temperature of the suction surface of a mounter device or the like (not shown) is lowered, and the molten bonding material 52 is solidified to bond the micro-vibrator 2 to the mounting substrate 3. Then, as shown in Fig. 11E, for example, the inside of the collet 302 is returned to normal pressure to release the vacuum suction of the micro-vibrator 2, the pickup mechanism 300 is retracted, and the collet 302 is removed from the recess 22 of the micro-vibrator 2.

[0063] Next, the suction by a mounter device or the like (not shown) is released, and the mounting substrate 3 to which the micro-vibrator 2 is bonded is removed from the suction surface. Then, the mounting substrate 3 is mounted on a circuit substrate or the like (not shown), and wire bonding is performed on the electrode films 531, 541 of the mounting substrate 3 to electrically connect the circuit substrate or the like to the electrode portion 53 and the outer frame portion 54 of the mounting substrate 3. Finally, for example, a cap material (not shown) is attached in a vacuum environment to the mounting substrate 3 or an external member to which the mounting substrate 3 is attached, and the micro-vibrator 2 is hermetically sealed in the internal space formed by the mounting substrate 3 and the cap material (not shown). Through these steps, the inertial sensor 1 according to the embodiment can be manufactured.

[0064] The above is the basic manufacturing method of the inertial sensor 1 of this embodiment. Note that, although the method of holding the micro-vibrator 2 has been described here by vacuum adsorbing the adsorption surface 22a of the recess 22 as a representative example, the method is not limited to this. For example, the configuration of the collet 302 may be changed to hold the micro-vibrator 2 by vacuum adsorbing the side wall on the surface 2a side of the recess 22, or the side wall may be mechanically pressed at two or more points to hold the micro-vibrator 2.

[0065] According to this embodiment, the inertial sensor 1 is formed by bonding a micro-vibrator 2 having a curved surface portion 21 capable of vibrating in a wine glass mode and a recessed portion 22, in which the mounting surface 22b of the recessed portion 22 on the back surface 2b side and the rim lower surface 611c of the rim 611 are positioned on the same plane to a mounting substrate 3. By positioning the mounting surface 22b and the rim lower surface 611c on the same plane, even if the micro-vibrator 2 is tilted with respect to the mounting substrate 3, the area variation of the rim 211 arranged opposite the multiple electrode portions 53 is reduced. Therefore, this inertial sensor 1 has the effect of suppressing the variation in the capacitance of each capacitor formed by the rim 211 and the multiple electrode portions 53, and improving the sensor accuracy.

[0066] (Modification of the first embodiment) In the above first embodiment, an example was described in which the adsorption surface 22a and the mounting surface 22b are parallel to each other, and the mounting surface 22b and the rim lower surface 211c are positioned on the same plane. However, this is not limited to this.

[0067] The micro-vibrator 2 may have a shape in which the mounting surface 22b and the rim lower surface 211c are located on the same plane, while the mounting surface 22b is not parallel to the chucking surface 22a, as shown in FIG. 12, for example. In this case, when the mounting surface 22b of the micro-vibrator 2 is arranged parallel to the mounting surface of the mounting board 3, as shown in FIG. 13, for example, the height position in the z direction of the rim lower surface 211c is the same in the left-right direction of the paper surface of FIG. 13. In other words, in the inertial sensor 1, the areas of the rims 211 arranged to face the multiple electrode parts 53 are all the same. Even if the micro-vibrator 2 is tilted with respect to the mounting board 3, the mounting surface 22b and the rim lower surface 211c are located on the same plane, and thus the inertial sensor 1 has reduced variation in the areas of the rims 211 arranged to face the multiple electrode parts 53.

[0068] This modification also provides the same effects as the first embodiment.

[0069] Second embodiment The inertial sensor 1 of the second embodiment will be described with reference to Fig. 14 and Fig. 15. Fig. 14 is a cross-sectional view showing a cross section corresponding to Fig. 9. Fig. 15 is a cross-sectional view showing a cross section corresponding to Fig. 3.

[0070] 14, the inertial sensor 1 of this embodiment differs from the above-described first embodiment in that the micro-vibrator 2 has a side through-hole 24, which is a through-hole formed on the side surface of the recess 22 near the adsorption surface 22a, and the bonding member 52 flows into the side through-hole 24. In this embodiment, this difference will be mainly described.

[0071] In this embodiment, the micro-vibrator 2 has a side through hole 24 connecting the front surface 2a and the back surface 2b of the substrate on the side surface of the recess 22 near the bottom surface on the front surface 2a, i.e., on the side wall portion near the adsorption surface 22a, as shown in FIG. 15 for example. The side through hole 24 is formed by, for example, irradiating a thin-walled substrate (such as quartz) constituting the micro-vibrator 2 with laser light to partially melt the substrate. The side through hole 24 can also be formed by, for example, opening a through hole in advance in an area of ​​the quartz plate 20 located slightly outside the support portion M2 of the mold M in the step shown in FIG. 4A for example. The side through hole 24 is formed in a position of the recess 22 lower than the height of the inner frame portion 51 in the z direction when the micro-vibrator 2 is mounted on the mounting substrate 3, as shown in FIG. 14 for example. The side through hole 24 is formed in two positions symmetrically in a top view, but is not limited thereto, and the number and positions of the holes can be changed as appropriate.

[0072] In this embodiment, a part of the bonding member 52 flows into the side through-hole 24 of the micro-vibrator 2 and can cover a part or all of the bottom surface of the recess 22 of the micro-vibrator 2 on the front surface 2a side, i.e., the adsorption surface 22a. In other words, even if the amount of the bonding member 52 is large, a part of the bonding member 52 flows into the side through-hole 24 of the micro-vibrator 2, and it is prevented that an excessive amount of the bonding member 52 is interposed between the mounting surface 22b and the mounting surface of the mounting board 3. In this case, the contact area between the micro-vibrator 2 and the bonding member 52 is increased compared to the first embodiment, and thus the bonding strength of the micro-vibrator 2 is improved.

[0073] According to this embodiment, the inertial sensor 1 can obtain the same effect as that of the first embodiment. In addition, since the side through-hole 24 is formed in the micro-vibrator 2, even if the amount of the bonding member 52 arranged on the mounting board 3 increases, a part of the bonding member 52 flows into the side through-hole 24. Therefore, it is possible to prevent the bonding member 52 more than necessary from being interposed between the mounting surface 22b and the mounting surface of the mounting board 3, and thus to prevent the micro-vibrator 2 from tilting with respect to the mounting board 3. In addition, when the bonding member 52 reaches the suction surface 22a, the contact area between the micro-vibrator 2 and the bonding member 52 increases, and the effect of improving the bonding strength is also obtained.

[0074] Third embodiment The inertial sensor 1 of the third embodiment will be described with reference to Fig. 16 to Fig. 18. Fig. 16 is a cross-sectional view showing a cross section corresponding to Fig. 9. Fig. 17 is a cross-sectional view showing a cross section corresponding to Fig. 3.

[0075] 16, the inertial sensor 1 of this embodiment differs from the above-described first embodiment in that the micro-vibrator 2 has a bottom surface through-hole 25 on the bottom surface of the recess 22 in the z direction, and a bonding member 52 flows into the bottom surface through-hole 25. In this embodiment, this difference will be mainly described.

[0076] In this embodiment, the micro-vibrator 2 has a bottom through-hole 25 that communicates with the mounting surface 22b on the bottom surface of the recess 22 in the z direction, as shown in FIG. 17. The bottom through-hole 25 is formed, for example, by the same method as the side through-hole 24 of the second embodiment. The bottom through-hole 25 may be formed, for example, by preparing a molding die M having a protruding portion M21 at the upper end of the support portion M2, as shown in FIG. 18, by polishing and removing all of the protruding portions of the recess 202 that follow the protruding portion M21. The bottom through-hole 25 is formed, for example, one at the center position of the mounting surface 22b, but is not limited thereto, and may be formed in multiple numbers, or may be formed at a position different from the center position of the mounting surface 22b, and the number and positions of the bottom through-holes may be changed as appropriate.

[0077] In this embodiment, a part of the bonding member 52 flows into the bottom through-hole 25 of the micro-vibrator 2, and can cover a part or all of the suction surface 22a of the recess 22 of the micro-vibrator 2. As a result, as in the second embodiment, an excessive amount of the bonding member 52 is prevented from being interposed between the mounting surface 22b and the mounting surface of the mounting board 3, and the contact area between the micro-vibrator 2 and the bonding member 52 is increased, thereby improving the bonding strength of the micro-vibrator 2. In addition, since the bottom through-hole 25 is located on the mounting surface 22b, even if air bubbles are present in the bonding member 52, the air bubbles can easily escape to the outside through the bottom through-hole 25, and the bonding between the micro-vibrator 2 and the mounting board 3 is more stable.

[0078] According to this embodiment, the inertial sensor 1 can obtain the same effects as those of the first embodiment. In addition, since the micro-vibrator 2 has the bottom through-hole 25 and a part of the bonding member 52 flows into the bottom through-hole 25, it is possible to suppress tilting of the micro-vibrator 2, reduce the influence of air bubbles on the bonding member 52, and improve the bonding strength between the micro-vibrator 2 and the mounting substrate 3.

[0079] (Modification of the third embodiment) The inertial sensor 1 of the third embodiment may have a configuration in which a support portion 55, which is a part of the mounting substrate 3, is inserted into the bottom through-hole 25 of the micro-vibrator 2, as shown in FIG.

[0080] Specifically, when the micro-vibrator 2 has a bottom through-hole 25, the mounting substrate 3 may further include a support portion 55 arranged in an inner region of the upper substrate 5 surrounded by the inner frame portion 51 in a top view, as shown in FIG. 20 for example. The support portion 55 has a diameter smaller than the inner diameter of the bottom through-hole 25 and can be inserted into the bottom through-hole 25. The support portion 55 is formed by etching, for example, at the same time as the inner frame portion 51, the electrode portion 53, and the outer frame portion 54. The inertial sensor 1 according to the modified example is joined to the mounting substrate 3 by a joining member 52 in a state in which the micro-vibrator 2 has the support portion 55 inserted into the bottom through-hole 25, as shown in FIG. 21 for example. When a plurality of bottom through-holes 25 are provided, the mounting substrate 3 may include the same number of support portions 55 as the number of bottom through-holes 25.

[0081] This modification also provides the same effects as those of the third embodiment. In addition, since the support pillars 55 are fitted into the bottom through-holes 25 when the micro-vibrator 2 is bonded to the mounting substrate 3, it is possible to easily align the micro-vibrator 2 with respect to the mounting substrate 3.

[0082] (Fourth embodiment) The inertial sensor 1 of the fourth embodiment will be described with reference to Fig. 22 to Fig. 24. Fig. 22 is a cross-sectional view showing a cross section corresponding to Fig. 9. Fig. 23 is a cross-sectional view showing a cross section corresponding to Fig. 3.

[0083] 22, the inertial sensor 1 of this embodiment differs from the above-described first embodiment in that the micro-vibrator 2 has a mounting surface recess 26 recessed toward the surface 2a on the mounting surface 22b side of the recess 22, and the mounting substrate 3 has a positioning groove 43. In this embodiment, this difference will be mainly described.

[0084] 23, in the present embodiment, the micro-vibrator 2 has a mounting surface recess 26 recessed toward the front surface 2a at the bottom of the recess 22 on the mounting surface 22b side. The micro-vibrator 2 has a protruding portion 27 protruding from the bottom surface of the mounting surface recess 26, and the tip surface of the protruding portion 27 forms the mounting surface 22b located on the same plane as the rim lower surface 211c.

[0085] In this embodiment, the mounting substrate 3 has an annular positioning groove 43 formed in an inner region surrounded by an inner frame portion 51 of the lower substrate 4 at a position corresponding to the protruding portion 27 of the micro-vibrator 2, as shown in Fig. 24 for example. The positioning groove 43 is formed, for example, in an etching process such as DRIE at the same time as the etching groove 41. The positioning groove 43 has a width that allows the protruding portion 27 of the micro-vibrator 2 to fit therein, as shown in Fig. 22 for example, and serves to facilitate the positioning of the micro-vibrator 2 with respect to the mounting substrate 3.

[0086] The micro-vibration body 2 of this embodiment is formed, for example, through the steps shown in Figures 25A and 25B. First, as shown in Figure 25A, a mold M for forming a three-dimensional curved surface is prepared, which has a recessed portion M22 on the tip surface of the support portion M2. Next, the quartz plate 20 is melted by a flame F to form the curved surface portion 201 and the recessed portion 202. At this time, the recessed portion 202 follows the recessed portion M22 as shown in Figure 25B, and later has a shape corresponding to the mounting surface recessed portion 26 and the protruding portion 27.

[0087] Although the manufacturing example of the micro-vibration body 2 using the mold M having the recessed portion M22 as the support portion M2 has been described, the present invention is not limited to this. For example, instead of the recessed portion M22, a mold having a through hole communicating with the bottom side of the fitting portion C1 of the cooling body C may be used, and the mounting surface recessed portion 26 may be formed by vacuum drawing, and the method of forming the mounting surface recessed portion 26 may be changed as appropriate.

[0088] According to this embodiment, the inertial sensor 1 can obtain the same effect as that of the above-described first embodiment. Moreover, in this inertial sensor 1, the micro-vibrator 2 has the mounting surface recess 26, and the protrusion 27 of the micro-vibrator 2 is inserted into the positioning groove 43 of the mounting substrate 3, so that the effect of facilitating positioning of the micro-vibrator 2 is also obtained.

[0089] (Modification of the fourth embodiment) The inertial sensor 1 of the fourth embodiment may be configured such that the micro-vibrator 2 further has a bottom surface through-hole 25 in the mounting surface recess 26 as shown in Fig. 26, and the mounting substrate 3 further has a support portion 55 as shown in Fig. 27, and these are joined together. In this inertial sensor 1, the support portion 55 of the mounting substrate 3 is inserted into the bottom surface through-hole 25 of the micro-vibrator 2 as shown in Fig. 28, for example.

[0090] According to this modification, in addition to the effects of the fourth embodiment, the positioning accuracy of the micro-vibrator 2 is improved by inserting the support portion 55 into the bottom through-hole 25, and the effect of the bonding member 52 on the air bubbles is reduced.

[0091] 29, the inertial sensor 1 according to this modification may have a configuration in which the recess 22 is filled with a bonding member 52. Since the recess 22 is filled with the bonding member 52 in this inertial sensor 1, a wire (not shown) can be connected to the bonding member 52 on the upper side in the z direction. For example, the inertial sensor 1 can directly connect one of the multiple electrode films 541 on the upper surface of the outer frame portion 54 to the bonding member 52 filling the recess 22 with a wire. In this case, the mounting board 3 does not require the bridge wiring 42.

[0092] The inertial sensor 1 of FIG. 29 can be manufactured, for example, as shown in FIG. 30, by attaching the micro-vibrator 2 having the bottom through-hole 25 and the mounting surface recess 26 to the mounting substrate 3 having the positioning groove 43 and the support 55, and then pouring the bonding member 52 into the recess 22 and solidifying it. Even with this configuration, the same effect as the above-mentioned modified example can be obtained. In addition, since the bonding area between the bonding member 52 and the micro-vibrator 2 is increased, the effect of further improving the bonding strength between the micro-vibrator 2 and the mounting substrate 3 can be obtained. Furthermore, since the bonding member 52 is poured into the recess 22 and bonded after the micro-vibrator 2 is attached to the mounting substrate 3, the micro-vibrator 2 is not placed on the bonding member 52 in a fluid state, and therefore no tilt due to the bonding member 52 occurs.

[0093] (Other embodiments) Although the present invention has been described based on the embodiment, it is understood that the present invention is not limited to the embodiment or structure. The present invention also includes various modifications and modifications within the equivalent range. In addition, various combinations and forms, and other combinations and forms including only one element, more than one, or less than one, are also within the scope and concept of the present invention.

[0094] (1) For example, FIG. 29 shows an example of an inertial sensor 1 in which the mounting substrate 3 has both a positioning groove 43 and a support portion 55, but the micro-vibrator 2 may not have a mounting surface recess 26 and the mounting substrate 3 may not have a positioning groove 43.

[0095] (2) The inertial sensor 1 according to the fourth embodiment and its modified example may be configured such that the protruding portion 27 of the micro-vibrator 2 is curved and bowl-shaped in cross section over the entire area, and does not have a flat portion, as shown in Fig. 31 for example. In this case, the micro-vibrator 2 has a structure in which the apex of the protruding portion 27 is the tip portion 28, for example, the tip portion 28 is annular and located on the same plane as the rim lower surface 211c. In other words, when the micro-vibrator 2 is mounted on the mounting substrate 3, the mounting surface 22b of the protruding portion 27 does not contact the mounting substrate 3 in a plane, but the tip portion 28 contacts the mounting substrate 3 at a point.

[0096] This micro-vibration body 2 can be manufactured by a process basically similar to that of the fourth embodiment, except that the process of removing the end portion 203 where the rim lower surface 211c is formed is stopped when the end portion 203 reaches the apex of the protrusion 27. For example, in the process of removing the end portion 203, this micro-vibration body 2 has the above structure by being ground by an amount corresponding to the distance between the surface of the mold M in contact with the quartz plate 20 and the tip surface of the support portion M2 shown in FIG. [Explanation of symbols]

[0097] 2...Micro vibrator, 2a...front surface, 2b...back surface, 20...thin base material, 201... curved surface portion, 202... recessed portion, 21... curved surface portion, 211... rim, 211c: rim lower surface, 22: recess, 22b: mounting surface, 24 ... through hole, 25 ... (bottom surface) through hole, 26 ... mounting surface recess, 27 protrusion, 3 mounting board, 4 lower board, 43 positioning groove, 5... upper substrate, 51... inner frame portion, 52... joining member, 53... electrode portion, 55···Support part, E···Sealing material

Claims

1. An inertial sensor, A micro-vibration body (2) is a thin-walled member having a front surface (2a) which is a surface on the side with a larger outer diameter and a back surface (2b) which is the opposite surface to the front surface, the micro-vibration body having a curved surface portion (21) having an annular curved surface and a bottomed cylindrical recessed portion (22) recessed from the curved surface portion toward the back surface; a mounting substrate (3) formed by joining an upper substrate (5) having a frame-shaped inner frame portion (51) and a plurality of electrode portions (53) arranged to surround the inner frame portion while being spaced apart from each other, to a lower substrate (4); a bonding member (52) arranged in an inner region of the mounting board surrounded by the inner frame portion, The micro-vibrator has a mounting surface (22b) that is a bottom surface of the recess on the back surface side and is disposed in the inner region and bonded to the mounting substrate via the bonding member, A rim (211) which is a part of the curved surface including the end portion opposite to the recess is hollow, A rim lower surface (211c) of the rim, which is a surface connecting the front surface and the back surface, is located on the same plane as the mounting surface or a tip portion (28) thereof, The micro-vibrator has, on the mounting surface, a mounting surface recess (26) recessed from the back surface toward the front surface, and a protrusion (27) protruding from the mounting surface recess toward the mounting surface, The mounting substrate has a positioning groove (43) corresponding to the protrusion, The protrusion is inserted into the positioning groove.

2. An inertial sensor comprising: A micro-vibration body (2) is a thin-walled member having a front surface (2a) which is a surface on the side with a larger outer diameter and a back surface (2b) which is the opposite surface to the front surface, the micro-vibration body having a curved surface portion (21) having an annular curved surface and a bottomed cylindrical recessed portion (22) recessed from the curved surface portion toward the back surface; a mounting substrate (3) formed by joining an upper substrate (5) having a frame-shaped inner frame portion (51) and a plurality of electrode portions (53) arranged to surround the inner frame portion while being spaced apart from each other, to a lower substrate (4); a bonding member (52) arranged in an inner region of the mounting board surrounded by the inner frame portion, The micro-vibrator has a mounting surface (22b) that is a bottom surface of the recess on the back surface side and is disposed in the inner region and bonded to the mounting substrate via the bonding member, A rim (211) which is a part of the curved surface including the end portion opposite to the recess is hollow, A rim lower surface (211c) of the rim, which is a surface connecting the front surface and the back surface, is located on the same plane as the mounting surface or a tip portion (28) thereof, The micro-vibrator has a side through hole (24) provided on a side surface of the recess in the vicinity of a bottom surface of the front surface and connecting the front surface and the back surface, An inertial sensor, wherein at least a portion of the joining member is inserted into the side through hole.

3. An inertial sensor, A micro-vibration body (2) is a thin-walled member having a front surface (2a) which is a surface on the side with a larger outer diameter and a back surface (2b) which is the opposite surface to the front surface, the micro-vibration body having a curved surface portion (21) having an annular curved surface and a bottomed cylindrical recessed portion (22) recessed from the curved surface portion toward the back surface; a mounting substrate (3) formed by joining an upper substrate (5) having a frame-shaped inner frame portion (51) and a plurality of electrode portions (53) arranged to surround the inner frame portion while being spaced apart from each other, to a lower substrate (4); a bonding member (52) arranged in an inner region of the mounting board surrounded by the inner frame portion, The micro-vibrator has a mounting surface (22b) that is a bottom surface of the recess on the back surface side and is disposed in the inner region and bonded to the mounting substrate via the bonding member, A rim (211) which is a part of the curved surface including the end portion opposite to the recess is hollow, A rim lower surface (211c) of the rim, which is a surface connecting the front surface and the back surface, is located on the same plane as the mounting surface or a tip portion (28) thereof, The micro-vibrator has a bottom surface through-hole (25) provided on the mounting surface, An inertial sensor, wherein at least a portion of the joining member is inserted into the bottom surface through-hole.

4. The micro-vibrator has a bottom surface through-hole (25) provided in a bottom surface of the mounting surface recess, The inertial sensor according to claim 1 , wherein at least a portion of the joining member is inserted into the bottom surface through-hole.

5. 5. The inertial sensor according to claim 3, wherein the mounting board has, in a region surrounded by the inner frame, a support column (55) to be inserted into the bottom through-hole.

6. A micro-vibration body (2) is a thin-walled member having a front surface (2a) which is a surface on the side with a larger outer diameter and a back surface (2b) which is the opposite surface to the front surface, the micro-vibration body having a curved surface portion (21) having an annular curved surface and a bottomed cylindrical recessed portion (22) recessed from the curved surface portion toward the back surface; A method for manufacturing an inertial sensor in which an upper substrate (5) having a frame-shaped inner frame portion (51) and a plurality of electrode portions (53) arranged to surround the inner frame portion while being spaced apart from each other is joined to a lower substrate (4) to form a mounting substrate (3), the upper substrate (5) being joined to a lower substrate (4) via a joining member (52), preparing the micro-vibrator; disposing the bonding member in an inner region of the mounting substrate that is surrounded by the inner frame portion; After arranging the bonding member, the recess of the micro-vibrator is arranged in the inner region, and a mounting surface (22b) which is a bottom surface of the recess on the back surface side is brought into contact with the bonding member; The bonding material is melted and then solidified to bond the micro-vibrator and the mounting substrate, and a rim (211) of the curved surface of the micro-vibrator, which is an end portion of the curved surface of the micro-vibrator opposite to the recess, is made hollow. In preparing the micro-vibrator, A thin substrate (20) of the order of micrometers is heated, melted, and solidified to form a curved surface portion (201) that will later become the curved surface portion, and a recessed portion (202) that will later become the recessed portion, and then the thin substrate is sealed with a sealant (E); The curved surface portion, the recessed portion, and a portion of the sealing material are removed by polishing to form the mounting surface and a rim lower surface (211c) that connects the front surface and the back surface of the rim, which are located on the same plane; A through hole (24, 25) is formed on the mounting surface or a side surface in the vicinity of the mounting surface, A method for manufacturing an inertial sensor, comprising the steps of: making the rim hollow by pouring a molten portion of the joining material into the through hole.

7. a micro-vibration body (2) which is a thin-walled member having a front surface (2a) which is a surface on the side with a larger outer diameter and a back surface (2b) which is the opposite surface to the front surface, the micro-vibration body (2) having a curved surface portion (21) with an annular curved surface, a bottomed cylindrical recess (22) recessed from the curved surface portion toward the back surface, and a through hole (25) formed in a mounting surface (22b) which is the bottom surface of the recess; A method for manufacturing an inertial sensor in which an upper substrate (5) having a frame-shaped inner frame portion (51), a plurality of electrode portions (53) arranged to surround the inner frame portion while being spaced apart from one another, and support portions (55) arranged in an area surrounded by the inner frame portion is joined to a lower substrate (4) to form a mounting substrate (3), the upper substrate (5) being joined to a lower substrate (4) via a joining member (52), preparing the micro-vibrator; inserting the support portion of the mounting substrate into the through hole of the micro-vibrator and placing the micro-vibrator on the mounting substrate; and after placing the micro-vibrator on the mounting substrate, pouring the bonding material into the recess and solidifying it to bond the micro-vibrator to the mounting substrate, and making a rim (211) of the curved portion of the micro-vibrator, which is an end portion opposite to the recess, into a hollow state. In preparing the micro-vibrator, A thin substrate (20) of the order of micrometers is heated, melted, and solidified to form a curved surface portion (201) that will later become the curved surface portion, and a recessed portion (202) that will later become the recessed portion, and then the thin substrate is sealed with a sealant (E); A method for manufacturing an inertial sensor, comprising removing the curved portion, the recessed portion, and a portion of the sealing material by polishing to form the mounting surface and a rim underside (211c) that connects the front surface and the back surface of the rim, which are located on the same plane.

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