Microvibrator manufacturing method

Abstract

To simply form a minute vibration body which includes a curved surface part having a three-dimensional curved surface shape and does not include a flat part in a rim in the curved surface part.SOLUTION: A base material 20 is prepared, which comprises: a flat part 203; and a curved surface part 201 being an inner peripheral part surrounded with the flat part and has a three-dimensional curved shape including a hemispherical shape projecting from one surface 203a of the flat part. While the base material 20 is rotated in an adsorptive retention state, an outer side surface 201a of the curved surface part 201 is irradiated with a laser beam, so as to separate the curved surface part 201 from the flat part 203.SELECTED DRAWING: Figure 6H

Description

[Technical Field]

[0001] The present invention relates to a micro-vibrator having a three-dimensional curved surface. of Manufacturing method to Regarding. [Background technology]

[0002] In recent years, the development of autonomous driving systems for vehicles has progressed, and these types of systems require highly accurate self-position estimation technology. For example, for so-called Level 3 autonomous driving, development is underway on a self-position estimation system equipped with a GNSS (Global Navigation Satellite System) and an IMU (Inertial Measurement Unit). The IMU is a six-axis inertial force sensor consisting of, for example, 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 currently available will be required.

[0003] The BRG (Bird-bath Resonator Gyroscope) is considered to be a promising gyro sensor for realizing such a highly sensitive IMU. It is made up of a micro-vibrator with a roughly hemispherical three-dimensional curved surface that vibrates in wine-glass mode and is mounted on a mounting board. This micro-vibrator has a Q value that indicates the state of vibration of 10. 6 This is expected to result in higher sensitivity than conventional methods.

[0004] An example of a method for manufacturing this type of microvibrator is that described in Patent Document 1. In the method for manufacturing a microvibrator described in Patent Document 1, a glass substrate is attached to a mold and heated while being depressurized to form a plurality of three-dimensional curved shapes, each of which is approximately hemispherical. The glass substrate is then cooled and formed with a plurality of curved surface portions of the three-dimensional curved shapes. The glass substrate is then attached to another mold, and flat portions located between adjacent curved surface portions are cut and separated by laser processing to obtain individual microvibrators. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Chinese Patent Application Publication No. 110749315 Summary of the Invention [Problem to be solved by the invention]

[0006] The micro-vibrator manufactured by the above method has a shape in which a flat portion remains on the end of the roughly bowl-shaped curved surface that is closer to the laser-processed separation portion, i.e., a flange is formed at the tip of the rim. The flange remaining on the rim of the curved surface hinders the vibration of the curved surface, causing a decrease in the Q value, and also hinders film formation when forming surface electrodes that cover the outer and inner surfaces.

[0007] Another method for manufacturing a microvibrator involves forming a curved surface portion of a three-dimensional shape on a glass substrate using the same method as above, then attaching the glass substrate to a jig and sealing it with resin, and then grinding away the flat portion of the outer periphery of the curved surface portion of the glass substrate along with the jig and resin. However, while this method makes it possible to manufacture a microvibrator that does not have a flange on the rim of the curved surface portion, it requires more steps and the glass substrate is prone to breakage during the resin sealing step and the subsequent grinding step, resulting in a lower yield.

[0008] In view of the above, the present invention provides a micro-vibrator that can be easily formed without having a flat portion on the rim of a curved surface portion having a three-dimensional curved surface shape. of Manufacturing method of The purpose is to provide. [Means for solving the problem]

[0009] In order to achieve the above object, the manufacturing method of the micro-vibrator according to claim 1 includes preparing a substrate (20) having a flat portion (203) and a curved portion (201) having a three-dimensional curved surface shape, surrounded by the flat portion, and protruding from one surface (203a) of the flat portion, and irradiating an outer surface (201a) of the curved portion with laser light to separate the curved portion from the flat portion. When irradiating a curved surface with laser light, the axis passing through the center point (P1) of the curved surface when viewed from the normal direction to the surface and along the normal direction is defined as the central axis (A C ) by suctioning a flat portion of the substrate, the substrate is rotated around the central axis as a rotation axis while holding the substrate, and laser light is irradiated onto the rotating substrate, and the suctioning of the flat portion of the substrate is performed by vacuum suction, and the rotation of the substrate is performed by pressing the outer surface of the rotating substrate with a push jig (63), and the rotation axis (A R ) while the substrate is being attracted, and the central axis of the rotating substrate is aligned with the rotation axis of the rotation mechanism. .

[0010] In this manufacturing method, a substrate with a three-dimensional curved surface is prepared, and then a laser beam is irradiated onto the outer surface of the curved portion to cut and separate the flat portion and the three-dimensional curved portion, thereby obtaining a microvibrator. As a result, a microvibrator with a structure in which no flange shape remains on the three-dimensional curved portion is obtained, and resin sealing and subsequent grinding and polishing processes are not required, improving yield.

[0015] The reference symbols in parentheses attached to each component indicate an example of the correspondence between the component and the specific components described in the embodiments described below. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a perspective cross-sectional view showing an example of an inertial sensor including a micro-vibrator according to an embodiment. [Figure 2] FIG. 2 is a cross-sectional view showing an example of a micro-vibrator according to the embodiment. [Figure 3] FIG. 2 is a cross-sectional view showing the cross-sectional configuration taken along line III-III in FIG. [Figure 4A] 10A to 10C are diagrams showing a process of preparing a member in a process of forming a three-dimensional curved surface shape of the microvibrator. [Figure 4B] FIG. 4B is a diagram showing a step subsequent to FIG. 4A. [Figure 5] FIG. 1 is a perspective view showing a micro-vibrator processing device. [Figure 6A] 4C is a diagram showing the manufacturing process of the micro-vibrator subsequent to FIG. 4B. [Figure 6B] FIG. 6B is a cross-sectional view showing a cross section taken along line VIB-VIB in FIG. 6A. [Figure 6C] 6C is an explanatory diagram for explaining the frictional force and centrifugal force acting on the substrate in the manufacturing process of the microvibrator following FIG. 6B. [Figure 6D] 6C is a diagram showing an example of a case where the central axis of the base material is misaligned with the rotation axis of the rotation mechanism in the manufacturing process of the microvibrator following FIG. 6B. [Figure 6E] FIG. 6E is a diagram showing the step of FIG. 6D as viewed from a different angle. [Figure 6F] FIG. 6F corresponds to FIG. 6E and shows the manufacturing process of the micro-vibrator subsequent to FIG. 6E. [Figure 6G] FIG. 6C is a diagram corresponding to FIG. 6E and showing the manufacturing process of the micro-vibrator subsequent to FIG. 6F. [Figure 6H] FIG. 6C is a diagram showing the manufacturing process of the micro-vibrator subsequent to FIG. 6G. [Figure 7] 6F is a diagram showing the results of SEM (abbreviation for Scanning Electron Microscope) observation of the underside of the rim of the micro-vibrator formed by the process of FIG. 6G. FIG. [Figure 8] FIG. 3 is a cross-sectional view showing a modified example of the micro-vibrator, corresponding to FIG. 2. DETAILED DESCRIPTION OF THE INVENTION

[0017] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following embodiments, identical or equivalent parts will be denoted by the same reference numerals.

[0018] (Embodiment) An inertial sensor 1 including a micro-vibrator 2 according to an embodiment will be described with reference to the drawings.

[0019] 1, in order to make the configuration of the inertial sensor 1 easier to understand, a lower substrate 4, an upper substrate 5, and a part of the micro-vibrator 2, which will be described later, of the inertial sensor 1 are omitted, and only a cross-sectional configuration of the micro-vibrator 2 is shown. In FIG. 3, in order to make the configuration of the inertial sensor 1 easier to understand, the outlines of an electrode portion 53 and an electrode film 531, which will be described later and are located in another cross section, are shown by dashed lines.

[0020] For ease of explanation, as shown in FIG. 1, one direction in the plane of the mounting substrate 3 will be referred to as the "x direction," a direction perpendicular to the x direction on the same plane will be referred to as the "y direction," and a direction normal to the xy plane will be referred to as the "z direction." The x, y, and z directions in FIG. 2 and subsequent figures correspond to the x, y, and z directions in FIG. 1, respectively. In addition, in this specification, "up" refers to the direction along the z direction in the figure, and refers to the side indicated by the arrow, and "down" refers to the side opposite to the top. Furthermore, in this specification, the state in which the inertial sensor 1, the micro-vibrator 2, or the mounting substrate 3 is viewed from above in the z direction will sometimes be referred to as a "top view."

[0021] 1, the micro-vibrator 2 according to the embodiment is preferably mounted on a mounting substrate 3 and used to configure an inertial sensor such as a gyro sensor like a BRG, but can also be used for other purposes such as a clock device, etc. In this specification, a case where the micro-vibrator 2 is used as a component of a BRG will be described as a representative example, but the application is not limited to this.

[0022] [Inertial Sensor] First, an example of an inertial sensor 1 having a micro-vibrator 2 will be described. As shown in Fig. 1, the inertial sensor 1 includes the micro-vibrator 2 and a mounting substrate 3, with a portion of the micro-vibrator 2 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 a curved surface portion 21 of the thin-walled micro-vibrator 2 that can vibrate in a wine-glass mode and a plurality of electrode portions 53 of the mounting substrate 3.

[0023] 2, the micro-vibrator 2 includes a curved surface portion 21 having an outline of a three-dimensional curved surface of a substantially hemispherical shape, and a connecting portion 22 extending from the apex side of the imaginary hemisphere formed by the curved surface portion 21 toward the center side of the hemisphere. The connecting portion 22 is a connecting portion that is connected to another member such as the mounting substrate 3, and is, for example, a cylindrical recess with a bottom, but is not limited to this and may be substantially columnar. For example, the curved surface portion 21 of the micro-vibrator 2 has a bowl-shaped three-dimensional curved surface, and the Q value of the vibration is 10 5 That's all.

[0024] The end of the curved surface portion 21 opposite the connection portion 22 is the rim 211, which has, for example, a substantially cylindrical shape. Note that the term "substantially cylindrical shape" here refers not only to a cylindrical shape in which the outer and inner surfaces of the rim 211 have the same diameter from top to bottom, but also to a cylindrical shape in which the diameter varies from top to bottom. In other words, the curved surface portion 21 has a rim 211 that is an annular portion with a circular curved surface shape. When the micro-vibrator 2 is mounted on the mounting substrate 3, the rim 211 is mounted so that the front surface 2a faces the multiple electrode portions 53 of the mounting substrate 3 and the multiple electrode portions 53 are equally spaced apart. When mounted on the mounting substrate 3, the curved surface portion 21, including the rim 211, is hollow and does not come into contact with other components. When mounted on the mounting substrate 3, the micro-vibrator 2 is configured so that the hollow rim 211 can vibrate in wine glass mode. The rim 211 is formed by cutting a three-dimensional curved portion of the base material that constitutes the microvibrator 2 using laser light irradiation, and has a shape that does not have a flange. A manufacturing method for this microvibrator 2 will be described later. The microvibrator 2 has a curved portion 21 that is approximately hemispherical or approximately bowl-shaped and does not have a flange on the rim 211, and a bottomed, tubular or approximately columnar connecting portion 22 that extends from a portion of the curved portion 21 that is located at the center when viewed from above toward the inner surface.

[0025] 2 and 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, with a surface electrode 23 covering part or all of both surfaces. The surface of the connecting portion 22 of the micro-vibrator 2 facing the back surface 2b serves as a mounting surface 22b that faces the mounting board 3. For example, the surface of the bottom surface of the connecting portion 22 opposite the mounting surface 22b serves as an adsorption surface 22a that is used to adsorb and transport the micro-vibrator 2.

[0026] The surface electrode 23 is formed, for example and without limitation, by a laminated film of a base material such as Cr (chromium) or Ti (titanium) and an arbitrary conductive material such as Au (gold) or Pt (platinum). The surface electrode 23 is formed on the front surface 2a and the back surface 2b of the micro-vibrator 2 by a vacuum film-forming method such as sputtering or vapor deposition. The surface electrode 23 is formed, for example, on at least the mounting surface 22b and the front surface 2a of the rim 211, so that these portions are electrically connected. The surface electrode 23 may be a solid shape that covers the entire front and back surfaces of the micro-vibrator 2, or may be patterned to have the above-described configuration and have a pattern shape that covers part of the front and back surfaces. For example, the portion of the surface electrode 23 that covers the mounting surface 22b of the connection portion 22 of the micro-vibrator 2 is connected to the mounting substrate 3 via a bonding member 52 made of a conductive material such as AuSn (gold-tin).

[0027] The micro-vibrator 2 is made of a laser-machinable material, such as quartz, glass containing additives such as borosilicate glass, metallic glass, silicon, or ceramic. The micro-vibrator 2 is not limited to the above-mentioned examples of material, as long as it can form the curved surface portion 21 and the connecting portion 22, which have 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 material through a forming process described below, resulting in a thin member on the order of micrometers, with the curved surface portion 21 and the connecting portion 22 having thicknesses of 10 μm to 100 μm. The micro-vibrator 2 has a millimeter-sized shape, for example, with the height direction being along the thickness direction of the mounting substrate 3, being 2.5 mm in height, and the outer diameter of the rim 211 on the surface 2a side being 5 mm.

[0028] As shown in FIG. 1 , the mounting substrate 3 includes a lower substrate 4 and an upper substrate 5, which are bonded together. For example, the mounting substrate 3 can be obtained by subjecting the lower substrate 4, which is made of borosilicate glass, an insulating material, to etching and wiring film formation, and then anodically bonding the upper substrate 5, which is made of silicon (Si), a semiconductor material, to the lower substrate 4 and patterning the resulting structure. The mounting substrate 3 includes, for example, on the upper substrate 5 side, a plurality of inner frame portions 51, a plurality of electrode portions 53 arranged spaced apart from each other and surrounding the inner frame portion 51, and an outer frame portion 54 spaced apart from and surrounding the plurality of electrode portions 53. The mounting substrate 3 also includes, for example, on the lower substrate 4 side, annular etching grooves 41 that surround the plurality of inner frame portions 51 while separating the inner frame portion 51 from the plurality of electrode portions 53, and a plurality of bridge wirings 42 that span the inside and outside of the etching grooves 41.

[0029] 3, the etching groove 41 is a groove provided between the inner frame portion 51 and the plurality of electrode portions 53, and is formed by wet etching. The etching groove 41 has a dimension corresponding to the outer diameter of the rim 211 of the micro-vibrator 2, and is provided so that the rim 211 does not come into contact with the mounting substrate 3 when the micro-vibrator 2 is mounted on the mounting substrate 3.

[0030] 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. For example, a plurality of bridge wirings 42 are provided, and one end of each bridge wiring 42 is connected to the inner frame portion 51 and the other end is connected to the outer frame portion 54 while spanning the etching groove 41 in the lower substrate 4, electrically connecting these together. This allows the mounting substrate 3 to apply a voltage to the surface electrode 23 of the micro-vibrator 2 via the outer frame portion 54, the bridge wiring 42, and the inner frame portion 51.

[0031] The inner frame 51 is formed together with the plurality of electrode portions 53 and the outer frame 54, for example, by performing dry etching such as DRIE (Deep Reactive Ion Etching) on ​​the upper substrate 5 that is anodically bonded to the lower substrate 4. The inner frame 51 has, for example, a circular ring shape when viewed from above, and is configured so that the connection portion 22 of the micro-vibrator 2 can be inserted or fitted into the enclosed area. For example, after arranging a bonding member 52 in the area enclosed by the inner frame 51 on the mounting substrate 3, the connection portion 22 of the micro-vibrator 2 is mounted on the bonding member 52 and heated and solidified, thereby mounting the micro-vibrator 2 on the mounting substrate 3.

[0032] The multiple electrode sections 53 are arranged at a distance from one another, and each has an electrode film 531 formed on its upper surface, as shown in FIG. 3 . The multiple electrode sections 53 are electrically connected to an external circuit board or the like, not shown, by, for example, connecting wires (not shown) to the electrode films 531. This allows the multiple electrode sections 53 to be electrically connected to, for example, an external circuit board (not shown), thereby enabling control of their potential. When the micro-vibrator 2 is mounted, each of the multiple electrode sections 53 is spaced a predetermined distance from the rim 211 of the micro-vibrator 2, and each electrode section 53 forms a capacitor with the micro-vibrator 2. In other words, the mounting substrate 3 can detect the capacitance between itself and the micro-vibrator 2 via the multiple electrode sections 53, or generate electrostatic attraction between itself and the micro-vibrator 2, causing the micro-vibrator 2 to vibrate in wine-glass mode.

[0033] The outer frame portion 54 has, for example, a frame shape when viewed from above that surrounds the inner frame portion 51 and the plurality of electrode portions 53 arranged around the inner frame portion 51. The outer frame portion 54 has, for example, at least one electrode film 541 made of Al or the like on its upper surface, and a wire (not shown) is connected to the electrode film 541.

[0034] The above is the basic configuration of the inertial sensor 1 including the micro-vibrator 2. The above-described inertial sensor 1 is merely an example, and the number, shape, dimensions, arrangement, etc. of the bridge wiring 42, inner frame portion 51, electrode portions 53, and outer frame portion 54 of the mounting substrate 3 on which the micro-vibrator 2 is mounted may be changed as appropriate.

[0035] [Method for manufacturing a micro-vibrator] Next, a method for manufacturing the micro-vibrator 2 will be described, but first, the process for processing the three-dimensional curved surface of the micro-vibrator 2 will be described.

[0036] For example, as shown in FIG. 4A, a quartz plate 20 is prepared as a base material made of a reflow material, a mold M for forming a three-dimensional curved surface, and a cooling body C for cooling the mold M. Note that the reflow material constituting the base material is not limited to quartz. The mold M includes, for example, a recess M1 that provides a space for forming the three-dimensional curved surface in the quartz plate 20, and a support portion M2 extending in the depth direction of the recess M1 at the center of the recess M1 to support a portion of the quartz plate 20 during processing. The mold M has a through-hole M11 for decompression formed in the bottom surface of the recess M1. The cooling body C includes a fitting portion C1 into which the mold M is fitted and an exhaust port C11 at the bottom surface of the fitting portion C1, and serves to cool the mold M when processing the quartz plate 20. The quartz plate 20 is arranged to cover the entire recess M1 of the mold M.

[0037] Next, as shown in FIG. 4B , a flame F is blown from a torch T toward the quartz plate 20 to melt the quartz plate 20. At this time, a vacuum is drawn into the recess M1 of the mold M through the exhaust port C11 of the cooling body C by a vacuum mechanism (not shown). As a result, the melted portion of the quartz plate 20 is stretched toward the bottom of the recess M1, and its central peripheral region is supported by the support members M2. After that, by stopping the heating of the quartz plate 20 and allowing it to cool, the quartz plate 20 is formed with a curved portion 201 having a substantially hemispherical three-dimensional curved shape and a recessed portion 202 that is supported by the support members M2 and has a recessed shape near the center of the curved portion 201. Furthermore, the portion of the quartz plate 20 located outside the recess M1 is a flat portion 203 located at the outer periphery of the curved portion 201 and has a flat shape, and the inner peripheral portion surrounded by the flat portion 203 is the curved portion 201. The method for heating the quartz plate 20 is not limited to the above example, and any method such as radiation, heat transfer, convection, or induction heating can be used.

[0038] Next, the pressure in the recess M1 of the mold M is returned to normal pressure, and the processed quartz plate 20 is removed from the mold M, and the processed quartz plate 20 is attached to a processing device 6 shown in FIG. 5, for example.

[0039] Here, the processing device 6 and the processing steps of the quartz plate 20 using the processing device 6 will be described with reference to FIGS. 5 to 6H.

[0040] 6A to 6H, for ease of viewing, a rotation mechanism 62 to which a chucking jig 61 (described later) is attached and other mechanisms are omitted. In FIGS. 6E to 6G, for ease of viewing, the outline of the curved surface portion 201 of the quartz plate 20 and its central axis A are shown. C 6E and 6F, the contour of the curved surface portion 201 of the quartz plate 20 in the rotating state is shown by a broken line, and the rotation axis A of the rotation mechanism 62 is also shown. R The outermost trajectory of curved surface portion 201 that revolves around the object is shown by a two-dot chain line. In Figures 6C, 6F, and 6G, the directions in which forces F1, F2, and F3, which will be described later, act are shown by outline arrows.

[0041] As shown in FIG. 5 , the processing device 6 includes, for example, a suction jig 61 for suction-holding the quartz plate 20, a rotation mechanism 62, a push jig 63, a base 64 for the push jig 63, and a laser light irradiation unit 65. The processing device 6 is capable of rotating the quartz plate 20 using the rotation mechanism 62 while holding the quartz plate 20 with the suction jig 61. The processing device 6 is configured such that the height position, push amount, and horizontality of the base 64 are adjustable using, for example, a height adjustment screw 641, a push amount adjustment screw 642, and a horizontal adjustment screw 643. As a result, the processing device 6 can adjust the position of the quartz plate 20 on the suction jig 61 by adjusting the relative position of the push jig 63 with respect to the suction jig 61 and pushing the rotating quartz plate 20 with the push jig 63. Details of the position adjustment of the quartz plate 20 using the push jig 63 will be described later. The processing device 6 is configured to adjust the position of the quartz plate 20 relative to the rotation axis of the rotation mechanism 62, and then irradiate laser light onto the curved portion 201 of the rotating quartz plate 20 using the laser light irradiation unit 65, thereby performing cutting processing.

[0042] 5, the "height position" of the pedestal 64 refers to the position of the pedestal 64 in the height direction D1, where the height direction D1 is a direction normal to the mounting surface 64a of the pedestal 64 to which the push jig 63 is attached. The "push amount" of the pedestal 64 refers to the amount of movement of the pedestal 64 in the push direction D2 before and after adjustment by the push amount adjustment screw 642, with the push direction D2 being the direction from the pedestal 64 toward the rotation axis of the rotation mechanism 62. The "degree of horizontality" of the pedestal 64 refers to the degree of horizontality of the mounting surface 64a.

[0043] 6A and 6B, the suction jig 61 has suction holes 611 for holding a prepared substrate (quartz plate 20). The suction holes 611 of the suction jig 61 are connected to a vacuum mechanism (not shown), and the suction holes 611 are configured to hold the flat portion 203 of the quartz plate 20 by vacuum suction. The suction jig 61 is attached to a rotation mechanism 62 by any method, such as screwing, and can be rotated by the rotation mechanism 62 while holding the quartz plate 20 by vacuum suction.

[0044] 6C, the suction jig 61 suctions the quartz plate 20 so that F1≧F2, where F1 is the frictional force generated between the quartz plate 20 and the suction jig 61 due to suction, and F2 is the centrifugal force acting on the quartz plate 20 due to rotation. Note that F1 and F2 are expressed by the following equations:

[0045] F1=m(r2πn)2 / r (1) F2 = μN (2) In equation (1), π, m, r, and n are the ratio of the circumference of the circle to the circumference of the quartz plate 20 (unit: kg), the radius of rotation of the quartz plate 20 (unit: m), and the number of rotations of the quartz plate 20 (unit: s -1 In equation (2), μ and N are the coefficient of static friction between the quartz plate 20 and the chucking jig 61, and the normal force (unit: N) acting on the quartz plate 20, respectively.

[0046] The rotation mechanism 62 is, for example, a motor, and rotates the suction jig 61. The rotation speed r of the quartz plate 20 by the rotation mechanism 62 is appropriately adjusted so that F1≧F2.

[0047] The pushing jig 63 has a head 631 that comes into contact with the outer surface 201a of the curved portion 201 of the rotating quartz plate 20, and is rotated along the rotation axis A of the rotation mechanism 62. R This is a jig used to adjust the position of the quartz plate 20 relative to the substrate.

[0048] Specifically, the rotation axis A of the rotation mechanism 62 when viewed from the normal direction to the suction surface 61a of the suction jig 61 is R and the central axis A of the curved surface portion 201 of the quartz plate 20C 6D, the central axis A of the curved surface portion 201 is misaligned. C This refers to an axis that runs along the normal direction when the quartz plate 20 on which the curved portion 201 is formed is viewed from the normal direction to one surface 203a of the flat portion 203, and that passes through the center point P1 located at the center of the curved portion 201.

[0049] Rotation axis A of the rotation mechanism 62 R and the central axis A of the curved surface portion 201 of the quartz plate 20 C When the quartz plate 20 is rotated in the misaligned state, the quartz plate 20 rotates around the central axis A, as shown in FIG. 6E. C is the rotation axis A R In this state, the centrifugal force acting on the quartz plate 20 is large, and in addition, the focal length of the laser beam irradiation fluctuates during the process of separating the curved portion 201 and the flat portion 203 by laser beam irradiation, which will be described later, causing problems. Therefore, by pushing the rotating quartz plate 20 with the push jig 63, the suction position on the suction jig 61 is changed, and the quartz plate 20 is rotated about the central axis A of the quartz plate 20. C The rotation axis A of the rotation mechanism 62 R and perform processing to match it.

[0050] Hereinafter, in this specification, for example, in a series of steps shown in FIGS. 6D to 6G, the central axis A of the curved portion 201 of the quartz plate 20 is C The rotation axis A of the rotation mechanism 62 R For convenience, the process of matching these two is called the "centering process."

[0051] More specifically, in the centering step, for example, the push jig 63 is moved by the push amount adjustment screw 642, and as shown in FIG. 6F, the outer surface 201a of the rotating quartz plate 20 is aligned with the rotation axis A by one surface of the head 631 made of any material such as a resin material. R At this time, the force with which the head 631 presses the curved portion 201 of the quartz plate 20 is defined as F3, which is greater than the friction force F2 and is set within a range that does not exceed the strength of the curved portion 201. As a result, the quartz plate 20 is held by the suction jig 61, and the central axis A of the curved portion 201 is aligned with the center axis A of the curved portion 201.C is the rotation axis A of the rotation mechanism 62 R The quartz plate 20 is then moved gradually along the suction surface 61a so as to approach the rotation axis A. R 6G, the curved surface portion 201 is finally pushed toward the central axis A C and the rotation axis A of the rotation mechanism 62 R As a result, the quartz plate 20 is in a state where the central axis A of the curved surface portion 201 coincides with the central axis A of the curved surface portion 201. C The curved surface portion 201 is rotated around the axis of rotation, and the centrifugal force acting on the curved surface portion 201 is reduced, stabilizing the rotation state.

[0052] In the centering step, the central axis A is measured while checking the rotation state of the quartz plate 20 using an imaging device such as a camera (not shown). C and rotation axis A R This can be done by adjusting the position of the push jig 63 until the rotation axis A is approximately aligned with the R After the position of the quartz plate 20 is adjusted relative to the laser beam irradiation unit 65, the laser processing can be smoothly started, and the processing time can be shortened.

[0053] The laser light irradiation unit 65 is a laser device capable of intermittently irradiating laser light of a predetermined wavelength with a predetermined spot diameter, and can be configured to irradiate laser light in the infrared region (for example, wavelength 1 μm to 1 mm) such as a CO2 laser. The laser light irradiation unit 65 can also be configured to irradiate laser light in the ultraviolet to near-infrared region (for example, wavelength 0.3 μm to 1 μm) such as a femtosecond laser, and can be appropriately changed depending on the reflow material that constitutes the micro-vibrator 2.

[0054] After the centering step, the laser light irradiation unit 65 intermittently irradiates the curved surface portion 201 of the rotating quartz plate 20 with laser light, as shown in FIG. 6H. By repeating this step, the quartz plate 20 rotates along the rotation axis A. RThe curved surface portion 201 is cut along the circumferential direction about the axis A, and the flat portion 203 and the curved surface portion 201 are separated. The portion separated from the quartz plate 20 by this cutting process using laser light irradiation becomes the micro-oscillator 2 according to the embodiment. In the micro-oscillator 2, the rim 211 is formed by the above-mentioned cutting process using laser light, and therefore the rim 211 has a central axis A on the outer surface thereof. C The shape has no flanges protruding in the radial direction about the axis or in the direction intersecting the outer surface.

[0055] In summary, the three-dimensional curved shape of the curved portion 21 and the connecting portion 22 of the microvibrator 2 are formed by setting a base material made of a reflow material in a mold M, heating and softening it, and then subjecting it to a decompression process, as shown in FIGS. 4A and 4B. Then, the base material on which the curved portion 201, the recessed portion 202, and the flat portion 203 have been formed is fixed by suction and rotated as shown in FIGS. 6D to 6H. After adjusting the position relative to the rotation axis, laser processing is performed, resulting in a configuration in which the rim 211 of the curved portion 21 does not have a flange. Thereafter, surface electrodes 23 are formed on the front and back surfaces by sputtering or the like, thereby completing the microvibrator 2.

[0056] This eliminates the need for the conventional resin sealing and grinding processes for removing the flange portion, and enables the curved surface portion 21 to be easily formed without a flange on the rim 211, which has the effect of improving the yield in manufacturing the microvibrator 2. Furthermore, because the rim 211 does not have a flange, film formation is not hindered by the flange when forming the surface electrode 23 on the microvibrator 2, which has the effect of stabilizing film formation of the surface electrode 23.

[0057] The cut surface of the micro-vibrator 2 formed by the laser beam irradiation, i.e., the lower surface 211a of the rim 211, which is the surface connecting the front surface 2a and the back surface 2b, has a wavy shape with periodic irregularities, as shown in Fig. 7, for example. This irregular shape has a height difference between the convex portions and the concave portions on the order of nanometers or micrometers, a width of the convex portions or the concave portions on the order of several μm to several tens of μm, and a configuration in which the convex portions and the concave portions are repeatedly arranged. This irregular shape is caused by the intermittent and repeated cutting by the laser beam irradiation.

[0058] The height difference between the convex and concave portions in the uneven shape of the lower surface 211a of the rim 211, and the width of the convex or concave portions, can be adjusted by changing irradiation conditions such as the duration of one laser beam irradiation, the number of irradiations per second, wavelength, and energy density. By adjusting the height difference and width on the lower surface 211a of the rim 211, the micro-vibrator 2 is configured so that the Q value of vibration can be designed to a desired value while maintaining the resonant frequency as a vibrator at a predetermined value. Furthermore, if the multiple electrode portions 53 facing the rim 211 on the mounting substrate 3 on which the micro-vibrator 2 is mounted are configured to be located on the portion of the lower substrate 4 facing the lower surface 211a of the rim 211, the opposing area between the electrode portions and the rim 211, and therefore the electrostatic capacitance, can be increased.

[0059] According to the embodiment, a substrate having a three-dimensional curved surface is rotated while being held by suction, and the central axis A of the curved surface portion 201 of the substrate is rotated. C The rotation axis A of the rotation mechanism 62 R After aligning the curved portion 201 with the flat portion 203, the curved portion 201 is laser-processed to cut and separate it from the flat portion 203, thereby obtaining the micro-vibrator 2. As a result, a micro-vibrator 2 is obtained that has a structure in which no flange shape remains in the three-dimensional curved portion, resin sealing and subsequent grinding and polishing processes are not required, and the film formation of the surface electrode 23 is stable, improving yield. Furthermore, because the lower surface 211a of the rim 211 has a periodic uneven shape, the micro-vibrator 2 can be designed to have a desired Q value by adjusting the height difference and width of the unevenness without changing the resonant frequency.

[0060] (Variation) 8, the micro-vibrator 2 can be configured such that the lower surface 211a of the rim 211 is located higher in the z direction than the mounting surface 22b of the connecting portion 22. In other words, the micro-vibrator 2 is configured such that the connecting portion 22 protrudes from the rim 211. This micro-vibrator 2 cannot be manufactured by the conventional method of forming a three-dimensional curved surface and then performing resin sealing and grinding, but it can be easily manufactured by changing the laser irradiation position of the laser light irradiation unit 65 shown in FIG. 6H in the manufacturing method of the above embodiment.

[0061] This modification also results in a micro-vibrator 2 that can achieve the same effects as the above embodiment. Furthermore, by configuring the connection portion 22 to protrude beyond the rim 211, the length of the rim 211 becomes relatively short, and by increasing the resonance frequency at which unintended and unnecessary vibrations occur, the effect of providing a structure that is resistant to disturbance vibrations is obtained. Furthermore, because the position in the z direction of the lower surface 211a of the rim 211 is higher than the mounting surface 22b of the connection portion 22, there is no need to form an etching groove 41 in the mounting substrate 3, and the effect of increasing the degree of freedom in designing the mounting substrate 3 is obtained.

[0062] (Other embodiments) Although the present disclosure has been described with reference to the embodiments, it is understood that the present disclosure is not limited to the embodiments or structures. The present disclosure also encompasses various modifications and modifications within the scope of equivalents. In addition, various combinations and forms, as well as other combinations and forms including only one element, more than one, or less than one, are also within the scope and spirit of the present disclosure.

[0063] (1) For example, in the above embodiment, the head 631 of the push jig 63 serving as the processing device 6 is described as being substantially rectangular plate-shaped, but this is not limited thereto. The head 631 may have any shape that allows for the centering process, and the surface that contacts the curved portion 201 of the substrate (e.g., quartz plate 20) may have a curved shape that corresponds to the outer diameter of the curved portion 201. Furthermore, the head 631 may have a configuration in which the portion that contacts the curved portion 201 is a protrusion that protrudes further than other portions. In this case, the protrusion may be configured to retract into the base when a force greater than a predetermined value is applied so as to prevent excessive force F3 from being applied to the curved portion 201. In this way, the shape and configuration of the head 631 may be appropriately changed depending on the outer diameter, strength, etc. of the curved portion 201 of the substrate.

[0064] (2) Fig. 5 shows an example in which the height, push amount, and horizontality (hereinafter collectively referred to as "height, etc.") of the base 64 of the processing device 6 can be manually adjusted using the screws 641 to 643, but this is not limiting. For example, the processing device 6 may be configured so that the height, etc. of the base 64 or the push jig 63 can be automatically adjusted using any mechanical mechanism.

[0065] (3) In the above embodiment, an example has been described in which the laser beam irradiation unit 65 is fixed and the substrate (e.g., quartz plate 20) is rotated to cut and separate the curved surface portion 201 and the recessed portion 202 from other portions, but the present invention is not limited to this. For example, while the substrate is fixed, the laser beam irradiation unit 65 may be moved to irradiate the curved surface portion 201 with laser beam in the circumferential direction about the central axis AC of the substrate, thereby cutting and separating the curved surface portion 201 and the recessed portion 202 from other portions. In this case, the processing device 6 may be configured to have, for example, a movement mechanism (not shown) that moves the laser beam irradiation unit 65 in the circumferential direction around the curved surface portion of the substrate.

[0066] (4) It goes without saying that in each of the above embodiments, the elements constituting the embodiments are not necessarily essential unless they are specifically stated as essential or are clearly considered essential in principle. Furthermore, in each of the above embodiments, when the numbers, values, amounts, ranges, etc. of the components of the embodiments are mentioned, they are not limited to the specific numbers unless they are specifically stated as essential or are clearly limited to a specific number in principle. Furthermore, in each of the above embodiments, when the shapes, positional relationships, etc. of the components are mentioned, they are not limited to the shapes, positional relationships, etc. unless they are specifically stated or are clearly limited to a specific shape, positional relationship, etc. in principle. [Explanation of symbols]

[0067] 2a...(micro-vibrator) surface, 2b...(micro-vibrator) back surface, 20...base material, 201...Curved surface area, 201a...Outside surface, 203...Flat area, 203a...One side, 21...Curved surface, 211...Rim, 201a...Bottom side 22 Connection part, 61 Adsorption jig, 62 Rotation mechanism, 63 Push jig, 631...head, 65...laser light irradiation unit, A C ...the central axis of the curved surface, A R Rotation axis of the rotation mechanism

Claims

1. A substrate (20) is prepared, which has a flat portion (203) and a curved portion (201) having a three-dimensional curved surface shape, which is a portion surrounded by the flat portion and protrudes from one surface (203a) of the flat portion; Irradiating a laser beam onto an outer surface (201a) of the curved surface portion to separate the curved surface portion from the flat portion, In irradiating the curved surface portion with the laser light, the flat portion of the base material is sucked around a central axis (A C ) that passes through a center point (P1) of the curved portion when viewed from a normal direction to the one surface and that is along the normal direction, thereby rotating the base material around the central axis as a rotation axis while holding the base material, and irradiating the laser light onto the rotating base material; The flat portion of the substrate is attracted by vacuum suction, In rotating the substrate, a push jig (63) is used to press the outer surface of the substrate in the rotating state, and the substrate is moved while being adsorbed toward a rotation axis (A R ) of a rotation mechanism (62) that rotates the substrate, thereby aligning the central axis of the substrate in the rotating state with the rotation axis of the rotation mechanism, in this method for manufacturing a micro-vibrator.

2. 2. The method for manufacturing a micro-vibrator according to claim 1, wherein, in the suction of the flat portion of the substrate, a frictional force acting on the substrate due to the suction of the flat portion is set to be equal to or greater than a centrifugal force acting on the substrate due to the rotation of the substrate.

3. 3. The method for manufacturing a micro-vibrator according to claim 1, wherein the outer surface is pressed by the pushing jig with a force greater than a frictional force acting on the base material due to adhesion of the flat portion.

4. 4. The method for manufacturing a micro-vibrator according to claim 3, wherein the outer surface is pressed by the pushing jig with a force that does not exceed the strength of the base material.

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