Inertial sensor and method of manufacturing the same

Abstract

The present application relates to an inertial sensor and a manufacturing method thereof, wherein the inertial sensor comprises a micro-vibrator, wherein the micro-vibrator (2) comprises a curved surface portion (21) having an annular curved surface and a recessed portion (22) recessed from the curved surface portion. A mounting substrate (3) comprises an inner frame portion (51) and an electrode portion (53) surrounding the inner frame portion. A bonding member (52) is arranged in an inner region of the mounting substrate surrounded by the inner frame portion. The recessed portion of the micro-vibrator has a bottom surface, which defines a mounted surface (22b) located in the inner region and is bonded to the mounting substrate through a bonding member. The curved surface portion has an edge (211), which includes an end portion on the side of the curved surface portion opposite to the recessed portion. The edge has an edge lower surface (211c), which is located on the same plane as the mounted surface or the tip end portion (28) of the mounted surface.

Description

Technical Field

[0001] The present invention relates to an inertial sensor including a micro-vibration body and a method for manufacturing the inertial sensor. Background Art

[0002] In recent years, vehicle autonomous driving systems have been developed. Such systems require a highly accurate self-positioning estimation technology. For example, to achieve so-called Level 3 autonomous driving, a self-positioning estimation system equipped with a global navigation satellite system (GNSS) and an inertial measurement unit (IMU) has been developed. For example, an IMU is a 6-axis inertial sensor consisting of a 3-axis gyro sensor and a 3-axis acceleration sensor. In the future, in order to achieve Level 4 or higher autonomous operation, an IMU with higher sensitivity than the existing system will be required.

[0003] As a gyro sensor for realizing such a high-sensitivity IMU, for example, a BRG (Bird-bath resonator gyro) is considered. The BRG includes a micro-vibrator having a three-dimensional curved surface, which vibrates in a wine glass mode and is mounted on a mounting substrate (for example, Patent Document 1). The micro-vibrator has a gyroscopic property of up to 10 6 Or higher Q value indicating the vibration state. Therefore, it is expected that this micro-vibrator can produce higher sensitivity than the previous structure.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent document 1: US 2019 / 0094024A1. Summary of the invention

[0007] As described in patent document 1, for example, by arranging a plate (such as quartz, which is adapted to the reflow process caused by heating) in a mold, and then melting and solidifying the plate, the micro-vibration body is formed. As a result, a three-dimensional curved surface that vibrates in a wine glass mode is formed. After the plate is treated with the above-mentioned process, the plate is covered with a sealing material. In addition, unnecessary parts are polished and removed by CMP (chemical mechanical polishing) and the like. Therefore, the micro-vibration body has a structure including a mounting component to be joined to a mounting substrate and a hollow three-dimensional shape component when mounted on the mounting substrate. In addition, the micro-vibration body includes an electrode film covering the front surface and the rear surface of the micro-vibration body. In addition, the micro-vibration body is arranged at a certain distance from a plurality of electrodes formed on the mounting substrate to be mounted on the micro-vibration body, thereby forming a capacitor therebetween.

[0008] The BRG described in patent document 1 includes a mounting substrate having a plurality of electrode portions arranged in a ring shape and spaced a certain distance from each other, and a micro-vibrator (BR) used as a resonator and mounted on the mounting substrate, so that the edge of the BRG becomes hollow. Note that when manufacturing the BRG, the micro-vibrator may be joined in a state where the mounting portion of the micro-vibrator is tilted relative to the mounting surface of the mounting substrate and tilted relative to the mounting substrate. In this case, in the micro-vibrator, the areas of the portions of the edge facing the plurality of electrode portions, respectively, may differ depending on the position. Therefore, in the BRG, the capacitance of the capacitor formed between the BR and each of the plurality of electrode portions changes, and the sensor accuracy may be reduced.

[0009] In view of the above problems, an object of the present invention is to provide an inertial sensor, wherein a micro-vibration body that vibrates in a wine glass mode is mounted on a mounting substrate, and changes in the area of ​​the edge of the micro-vibration body facing each of a plurality of electrodes on the mounting substrate are suppressed, thereby improving the accuracy of the sensor.

[0010] According to a first aspect of the present invention, an inertial sensor includes a micro-vibration body, which is a thin-walled member having a front surface and a rear surface, the front surface being a surface on a side having a large outer diameter, and the rear surface being a surface opposite to the front surface. The micro-vibration body includes a curved portion having an annular curved surface and a recessed portion, the recessed portion being recessed from the curved portion to the rear surface side. The inertial sensor also includes a mounting substrate, which includes a lower substrate and an upper substrate joined to each other. The upper substrate includes an inner frame portion having a frame shape and a plurality of electrode portions, which are separated from each other and surround the inner frame portion. The inertial sensor also includes a bonding member arranged in an inner region of the mounting substrate surrounded by the inner frame portion.

[0011] The recess of the micro-vibrator has a bottom surface defining a mounted surface on the rear surface side. The mounted surface is located in the inner area and is joined to the mounting substrate by a joining member. The curved portion has an edge in a hollow state. The edge is a part of the curved portion and includes an end of the curved portion on the side opposite to the recess. The edge has an edge lower surface, which is a surface connecting the front surface and the rear surface. The edge lower surface is located on the same plane as the mounted surface or the tip end of the mounted surface.

[0012] According to the inertial sensor, a micro-vibrator having a curved portion with a three-dimensional curved surface and a concave portion recessed from the curved portion is joined to a mounting substrate. The curved portion has an edge in a hollow state. The edge is a part of the curved portion and includes an end portion of the curved portion on the opposite side of the concave portion. In the inertial sensor, at the position where the micro-vibrator is joined to the mounting substrate, the mounted surface of the concave portion, or the tip end portion and the lower surface of the edge connecting the front surface and the rear surface are located on the same plane. That is, the mounted surface and the bottom surface of the edge are located at the same height. Therefore, even if the micro-vibrator is tilted relative to the mounting substrate, the change in the position of the edge relative to the plurality of electrode portions in the height direction is reduced, that is, the change in the area of ​​the edge facing the plurality of electrode portions is reduced. Therefore, the inertial sensor is configured to reduce the capacitance change of the capacitor and improve the sensor accuracy even when the micro-vibrator is tilted relative to the mounting substrate, and the capacitor is composed of the micro-vibrator and the plurality of electrode portions of the mounting substrate.

[0013] According to a second aspect of the present invention, a method for manufacturing an inertial sensor.

[0014] The inertial sensor includes a micro-vibrator, which is a thin-walled member having a front surface and a rear surface, wherein the front surface is a surface on the side with a larger outer diameter, and the rear surface is a surface opposite to the front surface, and the micro-vibrator includes a curved surface portion having an annular curved surface and a recessed portion recessed from the curved surface portion to the rear surface side. The inertial sensor also includes a mounting substrate, wherein the mounting substrate includes a lower substrate and an upper substrate joined to each other, the upper substrate includes an inner frame portion having a frame shape and a plurality of electrode portions, the plurality of electrode portions are separated from each other and surround the inner frame portion, and the micro-vibrator and the mounting substrate are joined to each other by a joining member. The method includes preparing a micro-vibrator.

[0015] The method also includes arranging a joining member in an inner region surrounded by an inner frame portion in the mounting substrate. The method also includes positioning the recess of the micro-vibration body in the inner region after arranging the joining member, and contacting the mounted surface (i.e., the bottom surface of the recess on the rear surface side) with the joining member. The method also includes melting the joining member, then solidifying the joining member, so that the micro-vibration body is joined to the mounting substrate, and the edge is in a hollow state, and the edge is the end of the curved portion of the micro-vibration body on the side opposite to the recess. The preparation of the micro-vibration body includes heating and melting a micron-level thin-walled base material, solidifying the thin-walled base material to form a curved surface portion to be a curved portion and a concave portion to be a concave portion, and then sealing the thin-walled substrate with a sealing material. The preparation of the micro-vibration body also includes removing a portion of the curved surface portion, the concave portion and the sealing material by polishing to form a lower edge surface, which connects the front surface to the rear surface so that the lower edge surface and the mounted surface are located on the same plane.

[0016] The manufacturing method of the inertial sensor includes: heating and melting a thin-walled base material, solidifying the thin-walled base material to form a curved surface portion and a concave portion, and then polishing the curved surface portion and the concave portion to form a micro-vibration body having a mounted surface and a lower surface of an edge located in the same plane, i.e., coplanar. The mounted surface and the lower surface of the edge of the micro-vibration body are located on the same plane. Therefore, even if the micro-vibration body is tilted during the process of engaging the micro-vibration body with a mounting substrate, the change of the area of ​​the edge that is set to face the multiple electrodes of the mounting substrate is reduced. Therefore, the method can manufacture such an inertial sensor: the inertial sensor is configured to reduce the capacitance change of an electrical device composed of a plurality of electrode portions of the micro-vibration body and the mounting substrate, and improve the accuracy of the sensor.

[0017] According to a third aspect of the present invention, a method for manufacturing an inertial sensor. The inertial sensor includes a micro-vibrator, which is a thin-walled member having a front surface and a rear surface, the front surface being a surface on the side with a larger outer diameter, and the rear surface being a surface opposite to the front surface, the micro-vibrator including a curved portion having an annular curved surface, a recess, and a through hole formed in a mounted surface defining a bottom surface of the recess, the recess being recessed from the curved portion to the rear surface side. The inertial sensor also includes a mounting substrate, the mounting substrate including a lower substrate and an upper substrate joined to each other, the upper substrate including an inner frame portion having a frame shape, a plurality of electrode portions separated from each other and surrounding the inner frame portion, and a column portion, the column portion being arranged in an area surrounded by the inner frame portion, and the micro-vibrator and the mounting substrate are joined to each other by a joining member.

[0018] The method includes preparing a micro-vibrator. The method also includes inserting a column of a mounting substrate into a through hole of the micro-vibrator to mount the micro-vibrator on the mounting substrate. The method includes injecting a bonding member into a recess after mounting the micro-vibrator on the mounting substrate, and curing the bonding member to bond the micro-vibrator to the mounting substrate, and making an edge in a hollow state, the edge being an end of a curved surface portion of the micro-vibrator on a side opposite to the recess.

[0019] The preparation of the micro-vibrator includes heating and melting a micron-sized thin-walled base material, solidifying the thin-walled base material to form a curved surface portion to be a curved portion and a concave portion to be a concave portion, and then sealing the thin-walled base material with a sealing material. The preparation of the micro-vibrator also includes removing the curved surface portion, the concave portion and a portion of the sealing material by polishing to form an edge lower surface, the edge lower surface connecting the front surface and the rear surface, so that the edge lower surface and the mounted surface are located on the same plane.

[0020] In addition to positioning the mounted surface and the lower surface of the edge on the same plane, which is similar to the method for manufacturing an inertial sensor according to the second aspect of the present invention, the present invention also includes a micro-vibration body having a through hole formed on the mounted surface. On the other hand, the method requires the preparation of a mounting substrate, the mounting substrate having a column portion to be inserted into the through hole formed in the mounted surface of the micro-vibration body. In addition, the method requires the support column of the mounting substrate to be inserted into the through hole of the micro-vibration body, and the micro-vibration body is mounted on the mounting substrate, and then the bonding member is injected into the recess of the micro-vibration body, and the bonding member is cured. In this way, the micro-vibration body is bonded to the mounting substrate. Even after the bonding step is implemented, the mounted surface and the lower surface of the edge are located on the same plane. Therefore, the method is capable of manufacturing an inertial sensor, which is configured to reduce the capacitance change of a capacitor composed of a plurality of electrode portions of a micro-vibration body and a mounting substrate, and improve the accuracy of the sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description made with reference to the accompanying drawings. In the accompanying drawings:

[0022] Figure 1 is a top view showing the inertial sensor according to the first embodiment.

[0023] Figure 2 is a perspective view showing a micro-vibrator used in an inertial sensor.

[0024] Figure 3 is shown along Figure 2 Cross-sectional view of the cross-sectional structure taken along the midline III-III.

[0025] Figure 4A 2 is a view showing a step for preparing a member for forming a micro-vibrator.

[0026] Figure 4B It is shown Figure 4A A view of step after step.

[0027] Figure 4C It is shown Figure 4B A view of step after step.

[0028] Figure 4D It is shown Figure 4C A view of step after step.

[0029] Figure 5 It is shown Figure 2 A top view of a mounting substrate on which a micro-vibrator is mounted.

[0030] Figure 6 is shown along Figure 5Cross-sectional view of the cross-sectional structure taken along the midline VI-VI.

[0031] Figure 7 is shown along Figure 5 Cross-sectional view of the cross-sectional structure taken along the midline VII-VII.

[0032] Figure 8 is shown along Figure 1 Cross-sectional view of the cross-sectional construction taken along midline VIII-VIII.

[0033] Fig. 9 is shown along Figure 1 Cross-sectional view of the cross-sectional structure taken along the midline IX-IX.

[0034] Fig. 10A is a cross-sectional view showing a micro-vibrator of a comparative example.

[0035] Fig. 10B It shows that Fig. 10A A cross-sectional view of a cross-sectional configuration of an inertial sensor of a comparative example in which a micro-vibrator is mounted on a mounting substrate.

[0036] Fig.11A 1 is a view showing a step of mounting a micro-vibrator in manufacturing an inertial sensor, and is a view showing a step of preparing components.

[0037] Fig. 11B It is shown Fig.11A A view of step after step.

[0038] Fig. 11C It is shown Fig. 11B A view of step after step.

[0039] Fig.11D It is shown Fig. 11C A view of step after step.

[0040] Fig.11E It is shown Fig.11D A view of step after step.

[0041] Fig.12 : is a cross-sectional view showing a modified example of the micro-vibration body of the inertial sensor according to the first embodiment.

[0042] Fig.13 is a cross-sectional view showing a modified example of the inertial sensor of the first embodiment.

[0043] Fig.14 is a cross-sectional view showing an inertial sensor according to a second embodiment.

[0044] Fig.15is a cross-sectional view showing a micro-vibration body of an inertial sensor according to a second embodiment.

[0045] Fig.16 is a cross-sectional view showing an inertial sensor according to a third embodiment.

[0046] Fig.17 is a cross-sectional view showing a micro-vibration body of an inertial sensor according to a third embodiment.

[0047] Fig.18 is an explanatory view showing an example of a method for forming a bottom through-hole according to the third embodiment.

[0048] Fig.19 is a top layout view showing a modified example of the inertial sensor according to the third embodiment.

[0049] Fig. 20 is a top view layout diagram showing a mounting substrate of a modified example of the inertial sensor according to the third embodiment.

[0050] Fig.21 is shown along Fig.19 Cross-sectional view of the cross-sectional structure taken along the midline XXI-XXI.

[0051] Fig. 22 is a cross-sectional view showing an inertial sensor according to a fourth embodiment.

[0052] Fig.23 is a cross-sectional view showing a micro-vibration body of an inertial sensor according to a fourth embodiment.

[0053] Fig.24 is a top view layout diagram showing a mounting substrate of an inertial sensor according to a fourth embodiment.

[0054] Fig.25A is shown for Fig. 22 A view showing a step of preparing a member in molding of a micro-vibration body.

[0055] Fig.25B It is shown Fig.24 A view of step after step.

[0056] Fig.26 is a cross-sectional view showing a micro-vibration body of a modified example of the inertial sensor according to the fourth embodiment.

[0057] Fig. 27 is a top view layout diagram showing a mounting substrate of a modified example of the inertial sensor according to the fourth embodiment.

[0058] Fig.28 is a cross-sectional view showing a modified example of the inertial sensor of the fourth embodiment.

[0059] Fig.29 is a cross-sectional view showing another modified example of the inertial sensor of the fourth embodiment.

[0060] Fig.30 It is shown Fig.29 1 is a view of a step of mounting a micro-vibration body in manufacturing an inertial sensor, and is an explanatory view showing a step of mounting the micro-vibration body on a mounting substrate and a subsequent step of filling a connector.

[0061] Fig.31 is a cross-sectional view showing another example of the shape of the microvibrator. DETAILED DESCRIPTION

[0062] Embodiments of the present invention will be described below with reference to the accompanying drawings. In the following embodiments, the same reference numerals are assigned to components that are identical or equivalent to each other for description.

[0063] (First embodiment)

[0064] Will refer to Figure 1-9 An inertial sensor 1 according to one embodiment is described.

[0065] exist Figure 2 In order to facilitate understanding of the structure of the micro-vibration body 2 to be described later, a cross section of the micro-vibration body 2 is shown by omitting a portion of the micro-vibration body 2, and the outer shell of the micro-vibration body 2 is shown by a dotted line. Figure 2 Portions not visible from the angle shown.

[0066] For ease of explanation, the following Figure 1 As shown, the direction along the left-right direction in the view is called the "x direction", the direction orthogonal to the x direction in the view is called the "y direction", and the normal direction orthogonal to the xy plane is called the "z direction". Figure 3 The x, y and z directions in the views in the figure and in the subsequent figures correspond to Figure 1 In addition, in this specification, "up" means the direction along the z direction in the drawing, and means the direction along the arrow, and "down" means the direction opposite to the up direction. In addition, in this specification, for example, Figure 1 As shown, the state in which the inertial sensor 1 or the mounting substrate 3 is viewed from the upper side along the z direction can be referred to as a “top view”.

[0067] (Basic structure)

[0068] like Figure 1As shown, the inertial sensor 1 includes, for example, a micro-vibration body 2 and a mounting substrate 3. A portion of the micro-vibration body 2 is bonded 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 capacitance between the micro-vibration body 2 and a plurality of electrode portions 53 of the mounting substrate 3 to be described later, the micro-vibration body 2 being thin-walled and configured to vibrate in a wine glass mode. The inertial sensor 1 is, for example, a gyro sensor having a BRG structure, and can be applied to an application to be mounted on a vehicle such as a car, however, the device can also be applied to other applications.

[0069] like Figure 1 and 2 As shown, the micro-vibration body 2 includes, for example, a curved portion 21 having an outer shape of a substantially hemispherical three-dimensional curved surface, and a concave portion 22 that is concave from the vertex side of the substantially hemispherical curved portion 21 toward the substantially hemispherical center side. The micro-vibration body 2 includes an edge 211, which is an end of the curved portion 21 opposite to the concave portion 22. The edge 211 has a substantially cylindrical shape. For example, in the micro-vibration body 2, the curved portion 21 has a bowl-shaped three-dimensional curved surface. The micro-vibration body 2 shows 10 6 The end of the curved portion 21 opposite to the recessed portion 22 is an edge 211. The microvibrator 2 is mounted on the mounting substrate 3 so that the front surface 2a of the edge 211 faces the plurality of electrode portions 53 of the mounting substrate 3 to be described later, and so that the plurality of electrode portions 53 are evenly spaced therebetween.

[0070] For example, Figure 3 As shown, the micro-vibrator 2 has a surface with a larger outer diameter, i.e., the front surface 2a, and an opposite surface, i.e., the rear surface 2b. The bottom surface of the recess 22 on the side of the rear surface 2b in the Z direction is a mounted surface 22b that is joined to the mounting substrate 3. For example, the bottom surface of the recess 22 of the micro-vibrator 2 on the side of the front surface 2a in the Z direction is a suction surface 22a, which is used to transport the micro-vibrator 2 when the micro-vibrator 2 is mounted on the mounting substrate 3. The curved surface 21 including the edge 211 is in a hollow state so as not to contact other components, and is configured so that when the micro-vibrator 2 is mounted on the mounting substrate 3, the hollow edge 211 vibrates in a wine glass mode.

[0071] For example, Figure 3As shown, the micro-vibrator 2 has such a shape that the edge 211 has an edge lower surface 211c, which is a surface connecting the front surface 2a and the rear surface 2b, and the edge lower surface 211c and the mounted surface 22b form the same virtual plane 22b1. This is the result of simultaneously forming the edge lower surface 211c and the mounted surface 22b by polishing and CMP in the process of forming the micro-vibrator 2 described later. The micro-vibrator 2 has a shape that makes the edge lower surface 211c and the mounted surface 22b located on the same plane. Therefore, when the micro-vibrator 2 is mounted on the mounting substrate 3, the position change of the edge 211 relative to the plurality of electrode portions 53 of the mounting substrate 3 is reduced in the height direction. In other words, the micro-vibrator 2 has a shape that reduces the change of the area of ​​the edge 211 facing the plurality of electrode portions 53 respectively when it is mounted on the mounting substrate 3. For example, in the micro-vibrator 2, the entire front surface 2a and the entire rear surface 2b are covered by the conductive layer 23.

[0072] The conductive layer 23 is formed, for example but not limited to, from a laminated film of a conductive material (such as Cr (chromium) or Ti (titanium) and Au (gold) or Pt (platinum) from the substrate side. The conductive layer 23 is used as an electrode film. The conductive layer 23 is formed on the front surface 2a and the rear surface 2b of the micro-vibrator 2 by an appropriate vacuum film forming method (such as sputtering or thin film deposition).

[0073] The micro-vibrator 2 is made of materials such as quartz, glass, silicon or ceramics. However, the micro-vibrator 2 is not limited to being formed by the above materials. The micro-vibrator 2 has a curved surface 21 and a recess 22 with a three-dimensional curved surface shape, and the micro-vibrator 2 is constructed to vibrate in a wine glass mode, which is sufficient. For example, the micro-vibrator 2 is formed by processing a thin-walled substrate made of the above materials through the forming step described later. Therefore, the micro-vibrator 2 is formed so that the thickness of the curved surface 21 and the recess 22 is 20μm to 80μm, which is a thin component of the micron level. The micro-vibrator 2 has a millimeter-sized shape, so that, for example, the micro-vibrator 2 is 2.5mm in the height direction, and the outer diameter of the micro-vibrator 2 on the front surface 2a side of the edge 211 is 5mm. The height direction is along the thickness direction of the mounting substrate 3.

[0074] The microvibrator 2 is formed by, for example, the following steps.

[0075] First, for example, Figure 4AAs shown, a quartz plate 20, a mold M for forming a three-dimensional curved surface shape, and a cooling body C for cooling the mold M are prepared. The mold M, for example, has a recess M1 that forms a space for forming a three-dimensional curved surface shape on the quartz plate 20, and a support portion M2 that is cylindrical and located at the center of the recess M1 and extends in the depth direction of the recess M1, and supports a portion of the quartz plate 20 during the process method. 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 is connected to the cooling body C. The cooling body C has a fitting portion C1 for mounting the mold M and a discharge port C11 formed on the bottom of the fitting portion C1 for discharge. The cooling body C is configured to cool the mold M when processing the quartz plate 20. The quartz plate 20 is arranged to cover the entire area of ​​the recess M1 of the mold M.

[0076] Then, for example, Figure 4B As shown, a flame F is applied from a torch T to the quartz plate 20 to heat the quartz plate 20 to melt the quartz plate 20. At this time, the concave portion M1 of the mold M is evacuated through the discharge port C11 of the cooling body C by a vacuum mechanism (not shown). Therefore, the melted portion of the quartz plate 20 is stretched toward the bottom surface of the concave portion M1. In addition, the central peripheral area of ​​the melted portion of the quartz plate 20 is supported by the support portion M2. Thereafter, the heating of the quartz plate 20 is stopped, and the quartz plate 20 is cooled. Therefore, the quartz plate 20 is formed with a curved surface portion 201 having a substantially hemispherical three-dimensional curved surface shape and a concave portion 202 supported near the center of the curved surface portion 201 by the support portion M2. In addition, a portion of the quartz plate 20 located on the outside of the concave portion M1 becomes a tip portion 203 located at the outer periphery of the curved surface portion 201 and having a flat shape.

[0077] Subsequently, the concave portion M1 of the mold M is returned to a normal pressure state, and the processed quartz plate 20 is removed. Figure 4C As shown, the quartz plate 20 is sealed by, for example, a sealing material E made of a curable resin material. Figure 4D As shown, the sealing material E is polished, for example, and CMP (Chemical Mechanical Polishing) is applied from the surface on the side close to the tip end portion 203. Thus, the sealing material E is removed together with the tip end portion 203 and the tip end of the concave portion 202.

[0078] Therefore, the quartz plate 20 has the curved surface portion 21 having a torroidal curved surface and the recessed portion 22 recessed from the curved surface portion 21. The edge lower surface 211c and the mounted surface 22b are located on the same plane.

[0079] Then, all the sealing material E is removed by a method such as heating or melting using a chemical solution, and the quartz plate 20 is taken out. Finally, after the above steps, a conductive layer 23 is formed on the front and rear surfaces of the quartz plate 20 by a film forming process such as sputtering, vapor deposition, atomic layer deposition (ALD), or chemical vapor deposition (CVD).

[0080] The micro-vibration body 2 is manufactured by, for example, the above-mentioned manufacturing process, and has a substantially semi-circular shape, which is rotationally symmetrical with the Z direction as the rotation axis. Note that the molding of the substrate is not limited to the above-mentioned method, and another method may be adopted. In addition, the micro-vibration body 2 may have a shape configured to vibrate in a wine glass mode, and is not limited to the shape of BR.

[0081] like Figure 5 As shown, for example, the mounting substrate 3 includes a lower substrate 4 and an upper substrate 5 bonded to each other. For example, the mounting substrate 3 is formed by anodically bonding the upper substrate 5 formed of a semiconductor material Si (silicon) to the lower substrate 4, which is formed of borosilicate glass as an insulating material. The mounting substrate 3 includes an inner frame portion 51, a plurality of electrode portions 53 that are separated from each other and arranged to surround the inner frame portion 51, and an outer frame portion 54 that is arranged to surround the electrode portion 53.

[0082] For example, in a top view, the inner frame portion 51 has a ring shape. It is sufficient that the inner frame portion 51 has a frame shape surrounding the region of the lower substrate 4 to which the microvibrator 2 is bonded. Note that the shape of the inner frame portion 51 is not limited to the above-described shape. Figure 8 and 9 As shown, for example, inner frame portion 51 has such dimensions that its outer diameter and inner diameter do not contact micro-vibration body 2 having a substantially M-shape in cross section.

[0083] The plurality of electrode portions 53 are disposed apart from each other so as to surround the inner frame portion 51 at positions on the radially outer side of the etching groove 41. Figure 5 As shown, for example, when viewed from the upper side, the plurality of electrode portions 53 have arc-shaped sides on the inner peripheral side and the outer peripheral side. When the inner peripheral side and the outer peripheral side of the electrode portion 53 are connected to each other, intermittent circles of different diameters are drawn. In other words, the plurality of electrode portions 53 have such a configuration that the annular band surrounding the inner frame portion 51 is evenly divided at predetermined intervals.

[0084] like Figure 6 As shown, for example, each of the plurality of electrode portions 53 has an electrode film 531 formed on its upper surface. For example, a wire (not shown) is connected to the electrode film 531, and the plurality of electrode portions 53 are electrically connected to an external circuit board (not shown) to achieve control of the potential. Figure 1 and 8As shown, for example, when the micro-vibration body 2 is mounted, the plurality of electrode portions 53 are in a state of being separated from the edge 211 of the micro-vibration body 2 by a predetermined distance, and each of the plurality of electrode portions 53 forms a capacitor with the micro-vibration body 2. That is, the mounting substrate 3 is configured to detect the capacitance with the micro-vibration body 2 through the plurality of electrode portions 53, and to generate an electrostatic attraction force with the micro-vibration body 2, so that the micro-vibration body 2 vibrates in the wine glass mode.

[0085] exist Figure 5 In the top view shown, the "inner peripheral side" of the mounting substrate 3 refers to the inner area surrounded by the inner frame portion 51 on the central side, and the "outer peripheral side" of the mounting substrate 3 refers to the side opposite to the inner peripheral side. Figure 1 , etc. show an example in which electrode portions 53 of 16 elements are evenly arranged on mounting substrate 3 and separated from each other to form a ring, but the present invention is not limited to this example. The number and arrangement of electrode portions 53 can be appropriately modified according to the shape and size of micro-vibrator 2.

[0086] The outer frame portion 54 has a single frame shape surrounding the inner frame portion 51 in a plan view, and is provided with an electrode film 541 formed on the upper surface of, for example, Al or the like. Figure 5 and 7 A wire (not shown) is connected to the electrode film 541, and the outer frame portion 54 is electrically connected to an external circuit board or the like (not shown). Therefore, the potential of the outer frame portion 54 can be controlled by an external power source (not shown) or the like.

[0087] In the mounting substrate 3, the annular etching groove 41 surrounding the inner frame portion 51 is formed at a position on the outer peripheral edge side of the annular inner frame portion 51 when viewed from the upper side. Therefore, when the micro-vibration body 2 is mounted on the mounting substrate 3, the curved surface portion 21 including the edge 211 of the micro-vibration body 2 becomes hollow, for example, Figure 8 and 9 shown.

[0088] For example, Figure 5 As shown, the mounting substrate 3 includes a bridge wire 42 that connects the inner frame portion 51 to the outer frame portion 54 while crossing the etching groove 41 of the lower substrate 4 in a top view. The bridge wire 42 is made of a conductive material such as Al (aluminum) and is arranged to pass between the plurality of electrode portions 53. The bridge wire 42 is electrically independent from the plurality of electrode portions 53. Figure 7As shown, for example, one end of the bridge wire 42 is covered with an outer frame portion 54, and the other end of the bridge wire 42 is covered with an inner frame portion 51. Therefore, the bridge wire 42 electrically connects the inner frame portion 51 with the outer frame portion 54, and makes the inner frame portion 51 and the outer frame portion 54 at the same potential. In addition, the bonding member 52 is arranged in the inner area of ​​the mounting substrate 3 surrounded by the inner frame portion 51. In addition, the micro-vibration body 2 is bonded to the bonding member 52. Therefore, the outer frame portion 54 is electrically connected to the micro-vibration body 2 through the bridge wire 42, the inner frame portion 51 and the bonding member 52. In other words, the mounting substrate 3 is constructed to adjust the potential of the micro-vibration body 2 by adjusting the potential of the outer frame portion 54. The number and arrangement of the bridge wires 42 are not limited Figure 5 Examples are shown and can be changed as needed.

[0089] The mounting substrate 3 can be manufactured by, for example, the following steps.

[0090] First, for example, a lower substrate 4 made of borosilicate glass is prepared, and a ring-shaped etching groove 41 is formed by wet etching with buffered hydrofluoric acid. Then, a bridge line 42 is formed across the etching groove 41 by a lift-off method such as sputtering Al to form a thin film. For example, the thickness of the bridge line 42 is about 0.1 μm.

[0091] Subsequently, for example, a Si substrate (later, upper substrate 5) made of Si is prepared and anodically bonded to the lower substrate 4 of borosilicate glass. Next, grooves for dividing a region to be the inner frame portion 51, a region to be the plurality of electrode portions 53, and a region to be the outer frame portion 54 are formed on the Si substrate by a known etching method.

[0092] Specifically, for example, groove etching is performed by DRIE (deep reactive ion etching) to expose the lower substrate 4 and separate the region to be the inner frame portion 51, the region to be the plurality of electrode portions 53, and the region to be the outer frame portion 54 from each other. Thus, the Si substrate becomes the upper substrate 5 including the inner frame portion 51, the plurality of electrode portions 53, and the outer frame portion 54 separated from each other. In addition, the etching groove 41 formed in the lower substrate 4 is exposed from the upper substrate 5 by the separation step of the Si substrate.

[0093] Finally, electrode films 531 and 541 are formed on the upper surfaces of the plurality of electrode portions 53 and the outer frame portion 54 by sputtering, for example. Through this step, the mounting substrate 3 having the above-mentioned structure can be obtained. Then, when the micro-vibration body 2 is mounted on the mounting substrate 3, the bonding member 52 is set in the positioning groove 43 of the lower substrate 4. The bonding member 52 is, for example, a paste-like conductive material having a conductive material such as AuSn (gold tin), Ag (silver), Au, etc., and is applied to the inner area surrounded by the inner frame portion 51.

[0094] For example, the plurality of mounting substrates 3 (each mounting substrate 3 having the above-described structure) can be obtained by forming regions to be the plurality of mounting substrates 3 on a wafer and separating the plurality of mounting substrates 3 into pieces by dicing or the like. Figure 5 The single mounting substrate 3 shown in FIG. 1 , etc. In other words, the mounting substrate 3 can be manufactured on a wafer level.

[0095] Furthermore, the mounting substrate 3 is, for example, in a vacuum environment with a vacuum degree less than a predetermined value, and a cover member (not shown) is attached so as not to contact the micro-vibration body 2 , thereby vacuum-sealing the micro-vibration body 2 .

[0096] The above is the basic structure of the inertial sensor 1. When driven, the inertial sensor 1 generates electrostatic attraction between a part of the plurality of electrode portions 53 and the micro-vibration body 2, causing the micro-vibration body 2 to vibrate in the wine glass mode. In the inertial sensor 1, when the micro-vibration body 2 is in a vibrating state, when the Coriolis force is applied from the outside, the micro-vibration body 2 is displaced and the position of the vibration mode node changes. The inertial sensor 1 is constructed to detect the angular velocity acting on the inertial sensor 1 by detecting the change of the vibration mode node based on the capacitance between the micro-vibration body 2 and the plurality of electrode portions 53.

[0097] In the inertial sensor 1, the microvibrator 2 having a shape in which the mounted surface 22b and the edge lower surface 211c are located on the same plane is bonded to the mounting substrate 3. Thus, the variation of each capacitance formed between the edge 211 and the plurality of electrode portions 53 is reduced.

[0098] Here, the above-described effects due to the shape of microvibrator 2 will be described, for example, in comparison with microvibrator 6 of a comparative example shown in FIG. 10A .

[0099] The micro-vibration body 6 of the comparative example has a substantially hemispherical curved portion 61, a recessed portion 62 recessed from the vertex of the substantially hemispherical curved portion 61 toward the center thereof, and an electrode film 63 covering the curved portion 61 and the recessed portion 62. The edge lower surface 611c of the edge 611, which is lower than the bottom surface 62b of the recessed portion 62, protrudes downward in the z direction beyond the bottom surface 62b of the recessed portion 62. Similar to the micro-vibration body 2 according to the present embodiment, the micro-vibration body 6 of the comparative example is composed of, for example Figures 4A to 4C , and then formed by the step of removing unnecessary parts before reaching the bottom surface 62b of the recess 62. Therefore, in the micro-vibrator 6 of the comparative example, as shown by the alternating long and short dotted lines, the edge lower surface 611c is located on the same plane, and is located on a different plane from the bottom surface 62b of the recess 62.

[0100] In the above-mentioned step of removing unnecessary parts, when the grinding surface is inclined relative to the bottom surface 62b of the recess 62, as shown in the micro-vibration body 6 in the comparative example, the protrusion degree of the edge 611 relative to the bottom surface 62b is different on the left and right sides in the cross-sectional view. The inertial sensor in which the micro-vibration body 6 of the comparative example is mounted on the mounting substrate 3 and the micro-vibration body 6 of the comparative example is inclined relative to the mounting substrate 3 is referred to as "the inertial sensor 100 of the comparative example".

[0101] Specifically, Fig. 10B As shown, the inertial sensor 100 of the comparative example is, for example, in a state in which the microvibrator 6 of the comparative example is tilted, and the regions of the plurality of electrode portions 53 of the edge 611 facing the mounting substrate 3 are greatly different from each other. For example, in the microvibrator 6 of the comparative example, the height position of the lower surface 611c of the edge along the z direction appears to be distributed. In addition, a portion of the edge 611 faces only a portion of the side surface of the electrode portion 53 along the z direction, and another portion of the edge 611 faces the entire side surface of the electrode portion 53 along the z direction. In this case, the capacitance of one electrode portion 53 in which the entire side faces the edge 611 and the electrode film 63 covering the edge 611 becomes larger than the capacitance of another electrode portion 53 in which only a portion of the side faces the edge 611 and the electrode film 63 covering the edge 611. That is, the inertial sensor 100 of the comparative example has a configuration in which the capacitance varies greatly between the plurality of electrode portions 53. Therefore, the accuracy of the sensor is reduced.

[0102] On the other hand, the inertial sensor 1 of the present embodiment is constructed by using the micro-vibration body 2 in which the mounted surface 22b and the edge lower surface 211c are located on the same plane. Therefore, even if the micro-vibration body 2 is inclined, the variation of the area of ​​the edge 211 disposed to face the electrode portion 53 is reduced. Therefore, the inertial sensor 1 produces an effect of reducing the capacitance variation of the capacitor composed of the edge 211 and the plurality of electrode portions 53, and an effect of improving the sensor accuracy compared with the inertial sensor 100 of the comparative example.

[0103] Fig. 10A is shown with Figure 3 Cross-sectional view of the corresponding cross section. Fig. 10B is a section showing a cross section corresponding to FIG. 9 .

[0104]

Manufacturing method of inertial sensor

[0105] Next, refer to Figures 11A to 11E The method of manufacturing the inertial sensor 1 of the present embodiment will be described. Since the manufacturing of the micro-vibrator 2 and the mounting substrate 3 has been described above, the step of bonding the micro-vibrator 2 to the mounting substrate 3 will be mainly described here.

[0106] Figures 11A to 11E Corresponds to Fig. 9 In addition, Figures 11C to 11E In FIG. 1 , for ease of viewing, only a portion of the pickup mechanism 300 to be described later is briefly shown, and the interior of the chuck 302 is shown by a dotted line. Fig.11D and 11E In the figure, the moving direction of the picking mechanism 300 is indicated by a white arrow for easy understanding.

[0107] First, if Fig.11A As shown, for example, the micro-vibrator 2 and the mounting substrate 3 manufactured by the above method are prepared. Then, for example, Fig. 11B As shown, the bonding member 52 is provided in the inner region surrounded by the inner frame portion 51. For example, as the bonding member 52, a conductive bonding material such as gold paste or silver paste is used, and the bonding member 52 is provided by coating with a syringe or the like.

[0108] Then, for example, the mounting substrate 3 is placed on a suction surface (not shown) of the mounting device, and the mounting substrate 3 is fixed by vacuum suction. The mounting device (not shown) has a heating mechanism configured to heat the suction surface.

[0109] Then, for example, Fig. 11CAs shown, a part of the pickup mechanism 300 is inserted into the suction surface 22a of the recess 22 of the micro-vibration body 2 on the front surface 2a side, and the micro-vibration body 2 is grasped by vacuum suction. The suction surface 22a of the recess 22 of the micro-vibration body 2 is a suction surface. The pickup mechanism 300 includes, for example, a base portion 301 and a chuck 302 having a substantially cylindrical shape. The base portion 301 is connected to a conveying portion and a vacuum mechanism (not shown). The pickup mechanism 300 is configured to perform vacuum suction and convey the suction object through the chuck 302. For example, in the pickup mechanism 300, the maximum diameter of the chuck 302 is smaller than the inner diameter of the recess 22, and the outer diameter of the tip end portion of the chuck 302 is smaller than the other parts. In addition, in the pickup mechanism 300, the length of the chuck 302 is greater than the depth of the recess 22 of the micro-vibration body 2. When the chuck 302 is inserted into the recess 22 of the micro-vibration body 2, the chuck 302 is configured not to contact the part of the micro-vibration body 2 other than the suction surface 22a of the micro-vibration body 2. Therefore, this configuration makes it possible to prevent the conductive layer 23 and the base material of the micro-vibration body 2 from being scratched when the micro-vibration body 2 is transported.

[0110] On the other hand, the mounting substrate 3 is heated in a state of being sucked by a mounting device (not shown) to melt or soften the bonding member 52. Then, for example, Fig.11D As shown, the mounted surface 22b of the recessed portion 22 of the micro-vibrator 2 is inserted into the inner frame portion 51 of the mounting substrate 3, and at the same time, the suction surface 22a of the micro-vibrator 2 is grasped by vacuum suction using the above-mentioned pickup mechanism 300. Subsequently, the micro-vibrator 2 is brought closer to the mounting substrate 3, and the mounted surface 22b of the micro-vibrator 2 is brought into contact with the bonding member 52.

[0111] Alignment of the micro-vibrator 2 relative to the mounting substrate 3 may be performed such that the micro-vibrator 2 and the mounting substrate 3 are imaged, and feature points are extracted by edge detection by a known image processing technique, thereby adjusting the relative positions.

[0112] Thereafter, the temperature of the suction surface of the mounting device (not shown) is lowered, and the melted bonding member 52 is solidified to bond the micro-vibrator 2 to the mounting substrate 3. Then, for example, Fig.11E As shown, the interior of the chuck 302 returns to normal pressure to release the vacuum suction of the micro-vibration body 2 , the pickup mechanism 300 is retracted, and the chuck 302 is pulled out of the recess 22 of the micro-vibration body 2 .

[0113] Subsequently, the suction force of the mounting device, etc. (not shown) is released, and the mounting substrate 3 with the micro-vibration body 2 attached thereto is removed from the suction surface. Then, the mounting substrate 3 is mounted on a circuit board or the like (not shown), and the electrode films 531 and 541 of the mounting substrate 3 are wire-bonded. In this way, the circuit board, etc., the electrode portion 53 of the mounting substrate 3, and the outer frame portion 54 are electrically connected to each other. Finally, for example, a cover (not shown) is attached to the mounting substrate 3 or an external member to which the mounting substrate 3 is mounted under a vacuum environment, and the micro-vibration body 2 is tightly sealed in the internal space formed by the mounting substrate 3 and the cover (not shown). Through such steps, the inertial sensor 1 according to the embodiment can be manufactured.

[0114] The above is the basic manufacturing method of the inertial sensor 1 of the present embodiment. Here, as a method of grasping the micro-vibrator 2, the case where the suction surface 22a of the recess 22 is vacuum-sucked has been described as a typical example, but the method is not limited to this example. For example, the configuration of the chuck 302 may be changed so that the side wall of the recess 22 on the front surface 2a side can be grasped by vacuum suction, or the side wall can be grasped by mechanically pressing the side wall at two or more locations.

[0115] According to the present embodiment, the micro-vibration body 2 includes a curved surface 21 and a recess 22, and is configured to vibrate in a wine glass mode. The mounted surface 22b of the recess 22 located on the side of the rear surface 2b and the lower edge surface 611c of the edge 611 are located on the same plane. The micro-vibration body 2 is mounted on the mounting substrate 3, and the inertial sensor 1 is manufactured. The mounted surface 22b and the lower edge surface 611c are located on the same plane, so that even if the micro-vibration body 2 is tilted relative to the mounting substrate 3, the change of the area of ​​the edge 211 that is arranged to face the multiple electrode portions 53 respectively can be reduced. Therefore, the inertial sensor 1 can suppress the change in the capacitance of the capacitor composed of the edge 211 and the multiple electrode portions 53, and produce the effect of improving the accuracy of the sensor.

[0116] (Modification of First Embodiment)

[0117] In the first embodiment, an example is described in which suction surface 22a and mounted surface 22b are parallel to each other, and in this example, microvibrator 2 having a shape in which mounted surface 22b and edge lower surface 211c are located on the same plane is used. The first embodiment is not limited thereto.

[0118] For example, Fig.12 As shown, the micro-vibrator 2 may have a shape in which the mounted surface 22b is not parallel to the suction surface 22a when the mounted surface 22b and the edge lower surface 211c are located on the same plane. Fig.13As shown, in the inertial sensor 1, when the mounted surface 22b of the microvibrator 2 is arranged parallel to the mounting surface of the mounting substrate 3, the height position of the edge lower surface 211c along the z direction is Fig.13 2 is the same height position as the mounted surface 22b of the micro-vibrator 2 in the left-right direction. In other words, in the inertial sensor 1, the areas where the edge 211 is set to face the plurality of electrode portions 53 are all the same. Therefore, even if the micro-vibrator 2 is tilted relative to the mounting substrate 3, the mounted surface 22b and the lower surface 211c of the edge are located on the same plane. Therefore, the inertial sensor 1 has a configuration in which the variation of the area where the edge 211 is set to face the plurality of electrode portions 53 is reduced.

[0119] According to this modification, the same effects as those of the first embodiment can be produced.

[0120] (Second embodiment)

[0121] Reference Fig.14 and 15 An inertial sensor 1 of a second embodiment is described. Fig.14 is a cross-sectional view showing a cross section corresponding to FIG. 9 . Fig.15 is shown with Figure 3 Cross-sectional view of the corresponding cross section.

[0122] For example, Fig.14 As shown, the inertial sensor 1 of the present embodiment is different from the inertial sensor 1 of the first embodiment in that the micro-vibration body 2 has a side through hole 24 which is a through hole formed in the side surface of the recess 22 near the suction surface 22a, and the bonding member 52 flows into the side through hole 24. This embodiment will mainly describe this difference.

[0123] For example, Fig.15 As shown, the microvibrator 2 of the present embodiment has a side through hole 24 in the side wall portion near the bottom surface in the side surface of the recess 22, that is, near the suction surface 22a. The side through hole 24 connects the front surface 2a of the substrate with the rear surface 2b. The side through hole 24 is formed, for example, by irradiating a thin-walled substrate (quartz, etc.) constituting the microvibrator 2 with a laser beam to partially melt the thin-walled substrate 20. In addition, the side through hole 24 can be formed by, for example, Figure 4A In the step shown, a through hole is pre-made in the region of the quartz plate 20 slightly outside the support portion M2 of the mold M. Fig.14As shown, for example, the side through hole 24 is formed in the recess 22 at a position lower than the height of the inner frame portion 51 in the z direction when the micro-vibration body 2 is mounted on the mounting substrate 3. For example, two side through holes 24 are formed to be spaced apart from each other at symmetrical positions in a top view. Note that the number and position of the side through holes 24 are not limited to these and can be appropriately changed.

[0124] In the present embodiment, a portion of the bonding member 52 flows into the side through hole 24 of the micro-vibration body 2, and can cover the bottom surface of the recess 22 of the micro-vibration body 2 on the surface 2a side, that is, can cover a portion or all of the suction surface 22a. In other words, even if the amount of the bonding member 52 is large, a portion of the bonding member 52 flows into the side through hole 24 of the micro-vibration body 2. Therefore, the excessive appearance of the bonding member 52 between the mounted surface 22b and the mounting surface of the mounting substrate 3 can be suppressed. In addition, in this case, compared with the first embodiment, the contact area between the micro-vibration body 2 and the bonding member 52 is increased, so that the bonding strength of the micro-vibration body 2 can be enhanced.

[0125] According to the present embodiment, the inertial sensor 1 is configured to produce similar effects to those of the first embodiment. In addition, the side through hole 24 is formed in the micro-vibration body 2. Therefore, even when the amount of the bonding member 52 provided to the mounting substrate 3 is large, a portion of the bonding member 52 flows into the side through hole 24. Therefore, this configuration makes it possible to prevent the bonding member 52 from intervening too much between the mounted surface 22b and the mounting surface of the mounting substrate 3. In addition, this configuration can prevent the micro-vibration body 2 from tilting relative to the mounting substrate 3. In addition, when the bonding member 52 also reaches the suction surface 22a, the contact area between the micro-vibration body 2 and the bonding member 52 increases, and the effect of improving the bonding strength can also be produced.

[0126] (Third Embodiment)

[0127] Will refer to Figures 6 to 8 An inertial sensor 1 of a third embodiment is described. Fig.16 is shown with Fig. 9 Cross-sectional view of the corresponding cross section. Fig.17 is shown with Figure 3 Cross-sectional view of the corresponding cross section.

[0128] like Fig.16 As shown, in the inertial sensor 1 of the present embodiment, for example, the micro-vibration body 2 has a bottom through hole 25 along the z direction on the bottom surface of the recess 22. The inertial sensor 1 of the present embodiment is different from that of the first embodiment in that the bonding member 52 flows into the bottom through hole 25. This embodiment will mainly describe this difference.

[0129] In this embodiment, if Fig.17As shown, for example, the micro-vibration body 2 has a bottom through hole 25 connected to the mounted surface 22b on the bottom surface of the recess 22 along the z direction. For example, the bottom through hole 25 is formed by a method similar to the method of forming the side through hole 24 of the second embodiment. Fig.18 As shown, the bottom through hole 25 can be formed by, for example, preparing a molding die M having a protruding portion M21 at the upper end of the support portion M2 and polishing and completely removing the portion of the concave portion 202 protruding due to the protruding portion M21. For example, one bottom through hole 25 is formed at the center position of the mounted surface 22b, but the present embodiment is not limited thereto. A plurality of bottom through holes 25 can be formed, or the bottom through hole 25 can be formed at other positions different from the center position of the mounted surface 22b. The number and position of the bottom through holes 25 can be appropriately changed.

[0130] In the present embodiment, a portion of the bonding member 52 flows into the bottom through hole 25 of the micro-vibration body 2, and can cover part or the entire suction surface 22a in the bottom surface 22a of the recess 22 of the micro-vibration body 2. Therefore, as in the second embodiment, the present structure enables the bonding member 52 to be inserted in excess between the mounted surface 22b and the mounting surface of the mounting substrate 3. In addition, by increasing the contact area between the micro-vibration body 2 and the bonding member 52, the effect of improving the bonding strength of the micro-vibration body 2 can be produced. In addition, the bottom through hole 25 is located in the mounted surface 22b, so even if there are bubbles in the bonding member 52, the bubbles can be easily escaped to the outside through the bottom through hole 25. Therefore, the present structure enables the effect of forming a more stable bond between the micro-vibration body 2 and the mounting substrate 3.

[0131] According to the present embodiment, the inertial sensor 1 is configured to produce similar effects to those of the first embodiment. In addition, the micro-vibration body 2 has a bottom through hole 25, and a portion of the bonding member 52 flows into the bottom through hole 25. Therefore, this configuration can produce the effects of suppressing the tilt of the micro-vibration body 2, reducing the influence of bubbles on the bonding member 52, and improving the bonding strength between the micro-vibration body 2 and the mounting substrate 3.

[0132] (Modification of the Third Embodiment)

[0133] like Fig.19 As shown, for example, the inertial sensor 1 of the third embodiment may have a configuration in which a column portion 55 as a part of the mounting substrate 3 is inserted into the bottom through hole 25 of the micro-vibration body 2 .

[0134] Specifically, for example, Fig. 20As shown, in the configuration in which the bottom through hole 25 is formed in the micro-vibration body 2, in a top view, the upper substrate 5 of the mounting substrate 3 may be configured to further include a column portion 55 provided in an inner region surrounded by the inner frame portion 51. The column 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 column portion 55 is formed, for example, by etching while forming the inner frame portion 51, the electrode portion 53, and the outer frame portion 54. Fig.21 As shown, for example, in the inertial sensor 1 according to the modified example, in a state where the column portion 55 is inserted into the bottom through hole 25, the micro-vibration body 2 is joined to the mounting substrate 3 by the joining member 52. Note that in a configuration in which a plurality of bottom through holes 25 are provided, the mounting substrate 3 may have the same number of column portions 55 as the number of bottom through holes 25.

[0135] According to this modification, the same effects as those of the third embodiment can be produced. In addition, when micro-vibration body 2 is joined to mounting substrate 3, column portion 55 is fitted in bottom through hole 25. Therefore, the effect of facilitating positioning of micro-vibration body 2 relative to mounting substrate 3 can be produced.

[0136] (Fourth embodiment)

[0137] Will refer to Figures 22 to 24 An inertial sensor 1 of a fourth embodiment is described. Fig. 22 is a cross-sectional view showing a cross section corresponding to FIG. 9 . Fig.23 is shown with Figure 3 Cross-sectional view of the corresponding cross section.

[0138] like Fig. 22 As shown, for example, the inertial sensor 1 of the present embodiment is different from the first embodiment in that the recess 22 of the micro-vibration body 2 has a mounted surface recess 26, which is located on the mounted surface 22b side and is recessed toward the surface 2a; and the positioning groove 43 is formed on the mounting substrate 3. This embodiment will mainly describe this difference.

[0139] In this embodiment, if Fig.23 As shown, for example, the micro-vibration body 2 has a mounted surface recess 26, which is located at the bottom of the recess 22 and on the mounted surface 22b side, and is recessed toward the front surface 2a. In the micro-vibration body 2, a protrusion 27 protrudes from the bottom surface of the mounted surface recess 26. The tip end surface of the protrusion 27 is the mounted surface 22b on the same plane as the edge lower surface 211c.

[0140] In this embodiment, for example, Fig.24As shown, the mounting substrate 3 is formed with an annular positioning groove 43 at a position located in the inner region of the lower substrate 4 surrounded by the inner frame portion 51, and the position corresponds to the protrusion 27 of the micro-vibrator 2. The positioning groove 43 is formed simultaneously with the etching groove 41 in an etching process using DRIE or the like. Fig. 22 As shown, for example, positioning groove 43 has a width that allows protrusion 27 of micro-vibrator 2 to enter. Positioning groove 43 facilitates positioning of micro-vibrator 2 relative to mounting substrate 3.

[0141] For example, by Fig.25A and 25B The micro-vibrator 2 of this embodiment is formed by the steps shown in Fig.25A As shown in FIG. 1 , a mold M is prepared for forming a three-dimensional curved surface. The mold M has a concave portion M22 on the tip end surface of the support portion M2. Subsequently, the quartz plate 20 is melted by a flame F to form a curved surface portion 201 and a concave portion 202. At this time, as shown in FIG. Fig.25B As shown, the concave portion 202 conforms to the shape of the concave portion 242 to have a shape corresponding to the mounted surface concave portion 26 and the protrusion 27.

[0142] An example of manufacturing a micro-vibration body 2 using a mold M having a recess M22 as a support portion M2 is described. The manufacture of the micro-vibration body 2 is not limited to this method. For example, a mold having a through hole instead of the recess M22 can be used. The through hole is connected to the bottom surface side of the matching portion C1 of the cooling body C. In this case, the mounted surface recess 26 can be formed by emptying. The method of forming the mounted surface recess 26 can be appropriately changed.

[0143] According to the present embodiment, the inertial sensor 1 is configured to produce an effect similar to that of the first embodiment. In addition, in the inertial sensor 1, the micro-vibration body 2 has the mounted surface recess 26, and the protrusion 27 of the micro-vibration body 2 is inserted into the positioning groove 43 of the mounting substrate 3. Therefore, an effect that facilitates the positioning of the micro-vibration body 2 can also be produced.

[0144] (Modification of the Fourth Embodiment)

[0145] In the inertial sensor 1 of the fourth embodiment, for example, Fig.26 As shown, the micro-vibration body 2 may further have a bottom through hole 25 in the mounted surface recess 26. Fig. 27 As shown, the mounting substrate 3 may further include a column portion 55. In addition, the bottom through hole 25 and the mounting surface recess 26 may be engaged with each other. For example, in the inertial sensor 1, as shown in FIG. Fig.28 As shown, the column portion 55 of the mounting substrate 3 is inserted into the bottom through hole 25 of the micro-vibrator 2 .

[0146] According to this modification, in addition to the effects of the fourth embodiment, the effect of improving the positioning accuracy of micro-vibration body 2 by inserting columnar portion 55 into bottom through-hole 25 and the effect of reducing the influence of bubbles in bonding member 52 can be produced.

[0147] like Fig.29 As shown, for example, the inertial sensor 1 according to this modification may have a configuration in which the recess 22 is filled with the bonding member 52. The recess 22 is filled with the bonding member 52. Therefore, the inertial sensor 1 has a configuration in which a wire (not shown) can be connected to the bonding member 52 on the upper side along the z direction. For example, the inertial sensor 1 has a configuration in which one of the plurality of electrode films 541 on the upper surface of the outer frame portion 54 can be directly connected to the bonding member 52 filling the recess 22 through a wire. In this case, the mounting substrate 3 does not require the bridge wire 42.

[0148] For example, Fig.30 As shown, the micro-vibration body 2 having the bottom through hole 25 and the mounted surface recess 26 can be attached to the mounting substrate 3 having the positioning groove 43 and the column 55, and then the bonding member 52 is injected into the recess 22 and the bonding member 52 is cured to manufacture. Fig.29 inertial sensor 1. Even with this construction, an effect similar to the above-mentioned modification can be produced. In addition, the bonding area between the bonding member 52 and the micro-vibration body 2 is increased. Therefore, the effect of further improving the bonding strength between the micro-vibration body 2 and the mounting substrate 3 can be produced. In addition, after the micro-vibration body 2 is attached to the mounting substrate 3, the bonding member 52 is injected into the recess 22 to bond the micro-vibration body 2 to the mounting substrate 3. Therefore, the micro-vibration body 2 is not placed on the bonding member 52 in a fluid state, and thus, tilting caused by the bonding member 52 is prevented.

[0149] (Other embodiments)

[0150] Although the present invention has been described according to examples, it is to be understood that the present invention is not limited to such examples or structures. The present invention also includes various modifications and improvements within the scope of equivalents. In addition, various combinations and modes and further combinations and modes including a single element or above or below these are also included in the scope or concept of the present invention.

[0151] (1) For example, reference has been made to Fig.29 The example of the inertial sensor 1 in which the mounting substrate 3 has both the positioning groove 43 and the column portion 55 is described. However, the micro-vibration body 2 may not have the mounted surface recessed portion 26 , and the mounting substrate 3 may not have the positioning groove 43 .

[0152] (2) Fig.31As shown, for example, in the inertial sensor 1 according to the fourth embodiment and the modification of the fourth embodiment, the entire area of ​​the protrusion 27 of the micro-vibration body 2 can have a shrunken bowl shape, and may not have a flat surface portion in a cross-sectional view. In this case, the protrusion 27 of the micro-vibration body 2 has a tip end 28 at the vertex. The tip end 28 has, for example, an annular shape and is located on the same plane as the lower surface 211c of the edge. In other words, when the micro-vibration body 2 is mounted to the mounting substrate 3, the mounted surface 22b of the protrusion 27 does not make surface contact with the mounting substrate 3, but the tip end 28 is in line contact with the mounting substrate 3.

[0153] The micro-vibration body 2 can be manufactured generally by a process similar to that of the fourth embodiment, but does not include a process of stopping the removal of the tip end portion 203 on which the edge lower surface 211c is formed when the apex of the protrusion 27 is reached. Fig.25B In the step of removing the tip end portion 203 shown in , the tip end portion 203 is ground at a distance between the surface of the mold M in contact with the quartz plate 20 and the tip end surface of the support portion M2 to obtain the configuration of the micro-vibration body 2. The tip end portion 203 may be ground at a distance smaller than the distance so that the tip end portion 28 remains unground.

Claims

1. An inertial sensor, comprising: a microvibrator which is a thin-walled member having a front surface which is a surface on a side having a large outer diameter and a rear surface which is a surface opposite to the front surface, the microvibrator including a curved surface portion having an annular curved surface and a concave portion which is concave to the rear surface side from the vertex side of the curved surface portion toward the center side of the curved surface portion; A mounting substrate including a lower substrate and an upper substrate joined to each other, the upper substrate including an inner frame portion having a frame shape and a plurality of electrode portions separated from each other and surrounding the inner frame portion; as well as a joining member provided in an inner region of the mounting substrate surrounded by the inner frame portion, wherein The recessed portion of the microvibrator has a bottom surface defining a mounted surface on the rear surface side, The mounted surface is located in the inner region and is joined to the mounting substrate by the joining member, The curved surface portion has an edge in a hollow state, The edge is a portion of the curved portion and includes an end portion of the curved portion on the opposite side of the recessed portion, The edge has an edge lower surface, the edge lower surface is a surface connecting the front surface and the rear surface, and The edge lower surface is located on the same plane as the mounted surface or a tip end portion of the mounted surface.

2. The inertial sensor according to claim 1, wherein The mounted surface of the microvibrator has a mounted surface recessed portion recessed from the rear surface toward the front surface, The mounting substrate has a positioning groove corresponding to the protruding portion of the microvibrator. The protrusion protrudes from the mounted surface recess toward the mounted surface, and The protrusion is inserted into the positioning groove.

3. The inertial sensor according to claim 1 or 2, wherein The micro-vibration body has a side through hole provided in the side surface of the recess in the front surface, The side through hole is arranged close to the bottom surface and connects the front surface with the rear surface, and The engagement member at least partially enters the side through hole.

4. The inertial sensor according to claim 1, wherein The micro-vibration body has a bottom through hole arranged in the mounted surface, and The engagement member at least partially enters the bottom through hole.

5. The inertial sensor according to claim 2, wherein The micro-vibration body has a bottom through hole provided in the bottom surface of the recessed portion of the mounted surface, and The engagement member at least partially enters the bottom through hole.

6. The inertial sensor according to claim 4 or 5, wherein The mounting substrate has a column portion in a region surrounded by the inner frame portion, and The column portion is inserted into the bottom through hole.

7. A method for manufacturing an inertial sensor, the inertial sensor comprising: A microvibrator, which is a thin-walled member having a front surface and a rear surface, the front surface being a surface on a side having a large outer diameter, the rear surface being a surface opposite to the front surface, the microvibrator including a curved surface portion having an annular curved surface and a concave portion, the concave portion being concave to the rear surface side from the vertex side of the curved surface portion toward the center side of the curved surface portion, and A mounting substrate, comprising a lower substrate and an upper substrate joined to each other, the upper substrate comprising an inner frame portion having a frame shape and a plurality of electrode portions, the plurality of electrode portions being separated from each other and surrounding the inner frame portion, the microvibrator and the mounting substrate being joined to each other by a joining member, the method comprising: preparing the micro-vibrator; providing the engaging member in an inner region of the mounting substrate surrounded by the inner frame portion; After providing the bonding member, positioning the recessed portion of the micro-vibrator body in the inner region and bringing a mounted surface that is a bottom surface on a rear surface side of the recessed portion into contact with the bonding member; and The bonding member is melted and then solidified to bond the microvibrator to the mounting substrate and to make an edge, which is an end of the curved surface portion of the microvibrator on the side opposite to the recessed portion, in a hollow state, wherein The step of preparing the micro-vibrator comprises: Heating and melting a micrometer-sized thin-walled base material and solidifying the thin-walled base material to form a curved surface portion to be the curved surface portion and a concave portion to be the concave portion, and then sealing the thin-walled base material with a sealing material; and The curved surface portion, the concave portion, and a portion of the sealing material are removed by polishing to form a lower edge surface connecting the front surface and the rear surface so that the lower edge surface and the mounted surface are located on the same plane.

8. A method of manufacturing an inertial sensor, the inertial sensor comprising: A microvibrator, which is a thin-walled member having a front surface and a rear surface, the front surface being a surface on a side having a large outer diameter, the rear surface being a surface opposite to the front surface, the microvibrator including a curved portion having an annular curved surface, a recessed portion, and a through hole formed in a mounted surface, the recessed portion being recessed from a vertex side of the curved portion toward a center side of the curved portion to a rear surface side, the mounted surface defining a bottom surface of the recessed portion, and A mounting substrate, comprising a lower substrate and an upper substrate joined to each other, the upper substrate comprising an inner frame portion having a frame shape, a plurality of electrode portions, and a column portion provided in a region surrounded by the inner frame portion, the plurality of electrode portions being separated from each other and surrounding the inner frame portion, the microvibrator and the mounting substrate being joined to each other by a joining member, the method comprising: preparing the micro-vibrator; inserting the column portion of the mounting substrate into the through hole of the micro-vibrator to mount the micro-vibrator on the mounting substrate; and After the micro-vibrator is mounted on the mounting substrate, the bonding member is injected into the recessed portion and the bonding member is cured so that the micro-vibrator is bonded to the mounting substrate and an edge is in a hollow state, the edge being an end of the curved surface portion of the micro-vibrator on the side opposite to the recessed portion, wherein The step of preparing the micro-vibrator comprises: Heating and melting a micrometer-sized thin-walled base material and solidifying the thin-walled base material to form a curved surface portion to be the curved surface portion and a concave portion to be the concave portion, and then sealing the thin-walled base material with a sealing material; and The curved surface portion, the concave portion, and a portion of the sealing material are removed by polishing to form a lower edge surface connecting the front surface and the rear surface so that the lower edge surface and the mounted surface are located on the same plane.

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