JP2023166384A - Vibration element, physical quantity sensor, inertial measurement unit, electronic apparatus, and movable body - Google Patents

Abstract

To provide a vibration element that can reduce noise vibration for the outside of the vibration element and a method for manufacturing the same, and to provide a physical quantity sensor, an inertial measurement unit, an electronic apparatus, and a movable body including the vibration element.SOLUTION: A vibration element comprises: a base; vibration arms that extend from the base and have arm parts located closer to the base side and weight parts located closer to a tip than the arm parts; and weight films that are arranged on the weight parts. The weight part has a first principal surface and a second principal surface that are in a front-back relation. The center of gravity of the weight part is at a position closer to the first principal surface side than a center plane in a thickness direction of the arm part. The center of gravity of the weight film is at a position closer to the second principal surface side than the center plane in the thickness direction of the arm part.SELECTED DRAWING: Figure 4

Description

The present invention relates to a vibrating element, a method of manufacturing a vibrating element, a physical quantity sensor, an inertial measurement device, an electronic device, and a moving body.

Conventionally, vibrating elements used in devices such as crystal resonators and vibrating gyro sensors have been known. A tuning fork type crystal vibrating piece described in Patent Document 1, which is an example of such a vibrating element, includes a base and a pair of vibrating arms that are bifurcated from the base and extend in parallel. Here, the tip of the vibrating arm is equipped with a weight part that is processed to have a thickness thinner than the thickness of the arm part of the vibrating arm, and the weight part has a metal film for frequency adjustment of the tuning fork type crystal vibrating piece. It is provided. Further, the tuning fork type piezoelectric vibrating piece described in Patent Document 2 includes a base and a pair of vibrating arms that are bifurcated from the base and extend in parallel, and the width is larger than the width of the arm part of the vibrating arm. A portion having a thickness thinner than a predetermined thickness is formed in the weight portion at the tip thereof. Metal films used for frequency adjustment are provided on both upper and lower surfaces of this weight.

Japanese Patent Application Publication No. 2006-311444 Japanese Patent Application Publication No. 2010-213262

However, in the tuning fork type crystal vibrating piece described in Patent Document 1 and Patent Document 2, the center of gravity of the structure consisting of the weight part and the metal film is oriented in the thickness direction with respect to the center plane in the thickness direction of the arm part of the vibrating arm. Because of the misalignment, when a pair of vibrating arms are vibrated in a direction toward or away from each other (in-plane direction), the vibrating arms generate vibrations that include a directional component in the thickness direction (out-of-plane direction). As a result, there is a problem in that the vibration component in the thickness direction leaks out of the vibrating element through the base and becomes a source of noise vibration outside the vibrating element.

An object of the present invention is to provide a vibrating element that can reduce noise vibrations external to the vibrating element and a method for manufacturing the same, and also to provide a physical quantity sensor, an inertial measurement device, an electronic device, and a moving body equipped with this vibrating element. It is about providing.

The present invention has been made to solve at least part of the above-mentioned problems, and can be realized as the following application examples or forms.

The vibration element of this application example has a base,
a vibrating arm extending from the base and having an arm located on the base side and a weight part located on the distal end side of the arm;
a weight membrane disposed on the weight portion,
The weight portion has a first main surface and a second main surface that are in a front and back relationship,
The center of gravity of the weight portion is located at a position closer to the first main surface than the center plane in the thickness direction of the arm portion,
The center of gravity of the weight membrane is located at a position closer to the second principal surface than the center plane in the thickness direction of the arm portion.

According to such a vibration element, the center of gravity of the weight part is located at a position closer to the first principal surface than the center plane of the arm part in the thickness direction, whereas the center of gravity of the weight membrane is located at the center of the arm part in the thickness direction. Since it is located closer to the second principal surface than the surface, the center of gravity of the structure including the weight portion and the weight film can be brought closer to the center surface (the center in the thickness direction of the vibrating arm). Therefore, unnecessary vibrations (vibrations in the thickness direction) of the vibrating arm can be reduced, and as a result, noise vibrations external to the vibrating element can be reduced.

In the vibration element of this application example, the weight portion has a first portion and a second portion thinner than the first portion, and the second main surface has the first portion and the second portion thinner than the first portion. It is preferable that the second portion has a stepped shape.

Thereby, with a relatively simple configuration, the center of gravity of the weight part can be located closer to the first main surface than the center plane in the thickness direction of the arm part.

In the vibration element of this application example, the weight portion has a portion where the thickness gradually decreases between the first portion and the second portion when viewed in plan from the thickness direction of the weight portion. It is preferable.

Thereby, the weight film can be easily formed continuously over the first portion and the second portion. Furthermore, it is possible to reduce cracks in the weight film due to the difference in level between the first portion and the second portion.

In the vibrating element of this application example, it is preferable that the width of the weight portion is larger than the width of the arm portion in a plan view from the thickness direction.
Thereby, the area of the weight portion in which the weight film can be formed can be increased.

In the vibrating element of this application example, it is preferable that the second portion is disposed on both sides of the vibrating arm in the width direction with respect to the first portion.
Thereby, the torsional moment of the vibrating arm can be reduced.

In the vibration element of this application example, it is preferable that the second portion is disposed on the opposite side of the base with respect to the first portion.

Thereby, the area of the second portion in plan view can be reduced. Another advantage is that the mass balance in the width direction of the weight portion is less likely to collapse.

In the vibrating element of this application example, it is preferable that the first portion surrounds the second portion when viewed in plan from the thickness direction of the weight portion.
This facilitates the design of the second portion.

In the vibrating element of this application example, it is preferable that the first main surface is a flat surface.
Thereby, it is not necessary to process the first main surface side of the weight portion in order to provide the first portion and the second portion on the weight portion, and as a result, the manufacturing process of the vibration element can be simplified.

In the vibration element of this application example, it is preferable that the weight film is disposed on the first portion and the second portion.
Thereby, the mass of the weight membrane can be increased. Furthermore, the formation of the weight membrane can be simplified.

In the vibrating element of this application example, it is preferable that the arm portion has a plane-symmetrical shape with respect to a center plane in the thickness direction of the arm portion.
Thereby, vibration in the thickness direction due to the shape of the vibrating arm can be reduced.

In the vibrating element of this application example, a first vibrating arm that is the vibrating arm extends from the base and has a first arm portion that is the arm portion, and a first weight portion that is the weight portion;
a second vibrating arm extending from the base and having a second arm located on the base side and a second weight part located on the distal end side of the second arm;
a first weight membrane that is the weight membrane disposed on the first weight part;
a second weight membrane disposed on the second weight part,
The center of gravity of the second weight portion is located at a position closer to the first main surface than the center plane in the thickness direction of the second arm portion,
Preferably, the center of gravity of the second weight membrane is located closer to the second main surface than the center plane of the second arm in the thickness direction.

Thereby, unnecessary vibration (vibration in the thickness direction) of both the first vibrating arm and the second vibrating arm can be reduced. Further, the centers of gravity of the first weight part and the second weight part are both located on the first main surface side (same side as each other), and the centers of gravity of the first weight film and the second weight film are both on the second main surface side. Since they are located on the same side (on the same side), it is easy to form these weight portions and weight membranes.

In the vibration element of this application example, a driving arm that vibrates,
Equipped with a detection arm that deforms in response to inertial force,
The base includes a base body and a connecting portion extending from the base body,
The driving arm is the vibrating arm and extends from the connecting portion,
Preferably, the detection arm extends from the base body.

This makes it possible to improve the characteristics of a so-called double T-shaped vibration element.

The vibrating element of this application example includes a drive arm extending from the base and driving and vibrating;
a detection arm extending from the base in a direction opposite to the drive arm and deforming in response to inertia;
Preferably, the driving arm is the vibrating arm.
Thereby, the characteristics of the so-called H-type vibration element can be improved.

In the vibration element of this application example, the weight film preferably includes a first weight film and a second weight film thinner than the first weight film.

Thereby, when adjusting the resonant frequency of the vibrating arm by removing a part of the weight film with an energy beam such as a laser, fine adjustment and coarse adjustment can be easily performed.

The method for manufacturing a vibrating element according to this application example includes a base, and a first principal surface and a second principal surface extending from the base and having a front-back relationship, and wherein the first principal surface and the second principal surface extend from the base, and the first principal surface and the second principal surface extend from the base, and the first principal surface and the second principal surface extend from the base. a step of forming a vibrating arm whose center of gravity is located on the first principal surface side;
forming a weight film on the vibrating arm, the center of gravity of which is located closer to the second main surface than the central plane of the vibrating arm in the thickness direction;
The method is characterized by including the step of adjusting the resonance frequency of the vibrating arm by adjusting the mass of the weight film.

According to such a method of manufacturing a vibrating element, the characteristics of the resulting vibrating element can be improved. In addition, since the weight film only needs to be placed on one side of the weight part (specifically, on the second main surface side), the manufacturing process of the vibrating element is simplified, and a part of the weight film is It is also possible to reduce droplets (dross) that are generated when adjusting the resonance frequency of the vibrating arm by removing them with an energy beam.

The physical quantity sensor of this application example includes the vibration element of this application example,
The present invention is characterized by comprising a package housing the vibrating element.

According to such a physical quantity sensor, the sensor characteristics (for example, detection accuracy) of the physical quantity sensor can be improved by utilizing the excellent characteristics of the vibration element.

The inertial measurement device of this application example includes the physical quantity sensor of this application example,
A circuit electrically connected to the physical quantity sensor.

According to such an inertial measurement device, the characteristics (for example, measurement accuracy) of the inertial measurement device can be improved by utilizing the excellent sensor characteristics of the physical quantity sensor.

The electronic device of this application example is characterized by including the vibration element of this application example.
According to such an electronic device, the characteristics (for example, reliability) of the electronic device can be improved by utilizing the excellent characteristics of the vibration element.

The moving body of this application example is characterized by including the vibration element of this application example.
According to such a moving body, the characteristics (for example, reliability) of the moving body can be improved by utilizing the excellent characteristics of the vibration element.

FIG. 1 is a plan view showing a vibration element according to a first embodiment of the present invention. 2 is a sectional view taken along line AA in FIG. 1. FIG. FIG. 2 is an enlarged plan view showing a weight portion and a weight film of a vibrating arm (drive arm) of a vibrating element. It is a sectional view taken along the line BB in FIG. 3. It is a sectional view taken along the line CC in FIG. 3. It is a flowchart which shows an example of the manufacturing method of a vibration element. FIG. 3 is a cross-sectional view showing a step of preparing a substrate in a vibrating element forming step. FIG. 3 is a cross-sectional view showing a process of forming a corrosion-resistant film and a resist film in a vibrating element forming process. FIG. 3 is a cross-sectional view showing a step of forming the outer shape of a vibrating element in a vibrating element forming process. FIG. 7 is a cross-sectional view showing a step of removing a part of the corrosion-resistant film in the vibrating element forming step. FIG. 3 is a cross-sectional view showing a step of forming a groove portion in a vibrating element forming step. FIG. 3 is a cross-sectional view showing a process of removing a corrosion-resistant film and a resist film in a vibrating element forming process. FIG. 3 is a cross-sectional view showing an electrode forming process. It is a sectional view showing a weight film formation process. It is a sectional view showing a frequency adjustment process. FIG. 7 is an enlarged plan view showing a weight portion and a weight film of a vibrating arm (drive arm) of a vibrating element according to a second embodiment of the present invention. It is a sectional view taken along the line CC in FIG. 16. FIG. 7 is an enlarged plan view showing a weight portion and a weight film of a vibrating arm (drive arm) of a vibrating element according to a third embodiment of the present invention. FIG. 7 is an enlarged plan view showing a weight portion and a weight film of a vibrating arm (drive arm) of a vibrating element according to a fourth embodiment of the present invention. 20 is a sectional view taken along line BB in FIG. 19. It is a top view which shows the vibration element based on 5th Embodiment of this invention. It is a top view which shows the vibration element based on 6th Embodiment of this invention. FIG. 1 is a sectional view showing a physical quantity sensor according to an embodiment of the present invention. 1 is an exploded perspective view showing an embodiment of an inertial measurement device of the present invention. 25 is a perspective view of a substrate included in the inertial measurement device shown in FIG. 24. FIG. 1 is a perspective view showing an embodiment of an electronic device (mobile type (or notebook type) personal computer) of the present invention. 1 is a plan view showing an embodiment of an electronic device (mobile phone) of the present invention. 1 is a perspective view showing an embodiment of an electronic device (digital still camera) of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an embodiment of a moving body (automobile) of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a vibrating element, a method for manufacturing a vibrating element, a physical quantity sensor, an inertial measuring device, an electronic device, and a moving body of the present invention will be described in detail based on embodiments shown in the accompanying drawings.

1. Vibration element and method for manufacturing the same <First embodiment>
First, the vibration element and its manufacturing method will be explained.

(vibration element)
FIG. 1 is a plan view showing a vibration element according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line AA in FIG. FIG. 3 is an enlarged plan view showing the weight portion and weight film of the vibrating arm (drive arm) of the vibrating element. FIG. 4 is a sectional view taken along line BB in FIG. FIG. 5 is a sectional view taken along the line CC in FIG. In each figure, the dimensions of each part are appropriately exaggerated as necessary, and the dimensional ratio between each part does not necessarily match the actual dimensional ratio. The position, direction, size, etc. of each part described below includes the range of manufacturing errors (for example, the difference is within ±1%), and is described in this specification as long as the necessary function of each part can be realized. It is not limited to the position, direction, size, etc.

Note that, for convenience of explanation, the following description will be made using three mutually orthogonal axes, namely, the x-axis, y-axis, and z-axis as appropriate. Below, the direction parallel to the x-axis is referred to as the "x-axis direction," the direction parallel to the y-axis is referred to as the "y-axis direction," and the direction parallel to the z-axis is referred to as the "z-axis direction." The tip side of the arrow indicating each axis of the y-axis and the z-axis is designated as "+", and the base end side is designated as "-". Further, the +z-axis direction side is also referred to as "upper", the -z-axis direction side as "lower", the +x-axis direction side as "right", and the -x-axis direction side as "left". Also, viewing from the z-axis direction is called "planar view." In FIG. 1, illustration of an electrode film 4, which will be described later, is omitted for convenience of explanation.

The vibration element 1 shown in FIG. 1 is a sensor element that detects angular velocity around the z-axis. This vibrating element 1 includes a vibrating piece 2 (see FIG. 1), an electrode film 4 (see FIG. 2) placed on the vibrating piece 2, and a weight film 3 (see FIG. 1) placed on the electrode film 4. reference) and has.

As shown in FIG. 1, the vibrating piece 2 has a so-called double T-shaped structure. Specifically, the vibrating element 2 includes a base 21, a pair of detection arms 22 and 23 (first and second detection arms) extending from the base 21, and a pair of drive arms 24 and 25 (first and second detection arms). drive arm) and a pair of drive arms 26, 27 (second drive arm).

Here, the base 21 is connected to a base main body 211 supported by a package 11 (see FIG. 22), which will be described later, and a connecting arm 212 extending from the base main body 211 along the +x axis direction. A connecting arm 213 extends along the -x axis direction opposite to the direction in which the arm 212 extends. The detection arm 22 (first detection arm) extends from the base main body 211 along the +y-axis direction that intersects the extending direction of the connecting arms 212 and 213. The arm) extends from the base body 211 along the −y-axis direction, which is opposite to the direction in which the detection arm 22 extends. The drive arm 24 (first drive arm) extends from the distal end region of the connecting arm 212 along the +y-axis direction, whereas the drive arm 25 (first drive arm) extends from the distal end region of the connecting arm 212. It extends along the −y-axis direction, which is opposite to the direction in which the drive arm 24 extends. Similarly, the drive arm 26 (second drive arm) extends from the distal end region of the connecting arm 213 along the +y-axis direction, whereas the drive arm 27 extends from the distal end region of the connecting arm 213 along the +y axis direction. It extends along the −y-axis direction, which is opposite to the direction in which it extends.

The detection arm 22 also includes an arm portion 221 (detection arm portion) extending from the base main body 211, and a weight portion 222 (detection arm portion) that is provided on the distal end side with respect to the arm portion 221 and has a width larger than the arm portion 221. (detection weight portion) and grooves 223 provided on each of the upper and lower surfaces of the arm portion 221. Similarly, the detection arm 23 includes an arm portion 231 (detection arm portion), a weight portion 232 (detection weight portion), and a pair of grooves 233. The driving arm 24 also includes an arm portion 241 (driving arm portion) extending from the connecting arm 212, and a weight portion 242 (driving arm portion) that is provided on the distal end side of the arm portion 241 and has a width larger than that of the arm portion 241. (driving weight part) and a pair of grooves 243 provided on the upper and lower surfaces of the arm part 241. Similarly, the drive arm 25 includes an arm portion 251 (drive arm portion), a weight portion 252 (drive weight portion), and a pair of grooves 253. The driving arm 26 also includes an arm portion 261 (driving arm portion) extending from the connecting arm 213, and a weight portion 262 (driving arm portion) that is provided on the distal end side of the arm portion 261 and has a width larger than that of the arm portion 261. (driving weight part) and a pair of grooves 263 provided on the upper and lower surfaces of the arm part 261.
Similarly, the drive arm 27 includes an arm portion 271 (drive arm portion), a weight portion 272 (drive weight portion), and a pair of grooves 273.

Note that at least one of the pair of upper and lower grooves 223, 233, 243, 253, 263, and 273 may be omitted. Further, each of the grooves 223, 233, 243, 253, 263, and 273 may have a pair of upper and lower portions communicating with each other. That is, the arm portions 221, 231, 241, 251, 261, and 271 may be provided with through holes that open on the upper and lower surfaces. Further, the width of the weight portions 222, 232, 242, 252, 262, 272 may be less than or equal to the width of the arm portions 221, 231, 241, 251, 261, 271.

Here, the arm portion 221 is a portion that bends (deforms) when the detection arm 22 vibrates (during detection vibration), and is a portion that detects electric charges generated along with the detection vibration of the detection arm 22 (described later). (a portion where a signal electrode 43 and a detection ground electrode 44 are provided). Similarly, the arm portion 231 is a portion that bends (deforms) when the detection arm 23 vibrates (at the time of detection vibration), and is a portion that detects electric charges generated along with the detection vibration of the detection arm 23 (described later). (a portion where a signal electrode 43 and a detection ground electrode 44 are provided). The arm portion 241 is a portion that bends (deforms) when the drive arm 24 vibrates (during drive vibration), and is a portion to which an electric field for driving the drive arm 24 is applied (a drive signal electrode described later). 41 and the drive ground electrode 42). Similarly, the arm portions 251, 261, and 271 are portions that bend (deform) when the drive arms 25, 26, and 27 vibrate (during drive vibration), and are This is a portion to which an electric field is applied (a portion where a drive signal electrode 41 and a drive ground electrode 42, which will be described later, are provided). Further, the weight portion 222 is a portion closer to the tip than the arm portion 221. Similarly, the weight portions 232, 242, 252, 262, and 272 are portions closer to the distal end than the arm portions 231, 241, 251, 261, and 271, respectively.

As shown in FIG. 3, the weight portion 242 includes a first portion 242a located on an extension line of the arm portion 241, and a pair of second portions 242b and 242c located on both sides of the first portion 242a in the width direction. have As shown in FIG. 4, the thickness t2 of each second portion 242b, 242c is thinner than the thickness t1 of the first portion 242a. Here, the first main surface 2a is flat, whereas the second main surface 2b is provided with steps 244 and 245 between the first portion 242a and the second portions 242b and 242c. The steps 244 and 245 include inclined surfaces, and the thickness of the weight portion 242 gradually increases from the second portions 242b and 242c toward the first portion 242a. Such second portions 242b, 242c can be formed by etching (anisotropic etching) the second main surface 2b of the weight portion 242, as described later.

As shown in FIG. 4, the center of gravity G1 of the weight portion 242 is the first principal surface 2a (lower surface) and It is located on the first main surface 2a side of the second main surface 2b (upper surface). That is, while the center of gravity G1 of the weight portions 242, 252, 262, 272 is located closer to the first principal surface 2a than the center plane CP of the arm portions 241, 251, 261, 271 in the thickness direction, the weight membrane 33 , 34, 35, and 36 are located closer to the second principal surface 2b than the center plane CP of the arm portions 241, 251, 261, and 271 in the thickness direction.
By shifting the center of gravity G1 in the thickness direction with respect to the center C in this manner, it is possible to maintain balance with the weight membrane 33 having the center of gravity G2 located on the opposite side of the center of gravity G1 of the weight portion 242, as described later. can. Similarly to the weight portion 242, the center of gravity G1 of the weight portions 252, 262, 272 is relative to the center C in the thickness direction of the drive arms 25, 26, 27, respectively. It is located on the first main surface 2a side of the first main surface 2a (lower surface) and second main surface 2b (upper surface) that are in a front-back relationship. Note that the center of gravity of the weight portions 222, 232 is also determined by the first principal surface (lower surface) and the second principal surface, which are the front and back sides of the weight portions 222, 232, with respect to the center in the thickness direction of the detection arms 22, 23. (upper surface) may be located on the first main surface side.

Here, “the central plane CP of the arm portion 241 in the thickness direction” is a surface perpendicular to the thickness direction (z-axis direction) of the arm portion 241, and is a surface on the first principal surface 2a side of the arm portion 241. This refers to a surface where the distance between the outermost point in the thickness direction and the outermost point in the thickness direction on the second main surface 2b side is equal. Further, the center planes of the arm portions 251, 261, and 271 in the thickness direction are also defined in the same manner as the center plane CP of the arm portion 241 in the thickness direction. The "weight film 33" refers to a laminate (on the drive arm 24) that has a larger mass per unit area than the electrode film 4 (the drive signal electrode 41 and the drive ground electrode 42) of the arm portion 241. Furthermore, the weight films 34, 35, and 36 are each defined similarly to the weight film 33.

Moreover, the depth d1 of the steps 244, 245 on the second main surface 2b, that is, the difference between the thickness t1 of the first portion 242a and the thickness t2 of the second portions 242b, 242c, is not particularly limited, but It is preferable that the depth is equal to the depth d2 of the groove 243 described above (see FIG. 5). Thereby, the above-described steps 244 and 245 can be formed together with the groove 243 by etching. The depth d1 of the step is preferably 0.1 times or more and 0.5 times or less, and more preferably 0.15 times or more and 0.4 times or less, with respect to the thickness t1 of the weight portion 242.

Further, the widths Wb and Wc of the second portions 242b and 242c may be equal to or different from each other, but it is preferable that the width Wc of the second portion 242c is larger than the width Wb of the second portion 242b. When the vibrating element 2 is formed by anisotropic etching of a Z-cut crystal plate, the average thickness of the second portion 242c becomes thicker than the average thickness of the second portion 242b due to the anisotropy. Therefore, by making the width Wc of the second portion 242c larger than the width Wb of the second portion 242b, the mass of the second portion 242b and the mass of the second portion 242c can be made equal.

In addition, the specific widths Wb and Wc of the second portions 242b and 242c are determined depending on the thickness and area of the weight film 33, which will be described later, and are not particularly limited, but may be determined depending on the widths of the first portion 242a. It is about 0.3 times or more and 0.8 times or less with respect to the width Wa. Further, the area of each of the second portions 242b and 242c in plan view is not particularly limited, but is, for example, about 0.1 times or more and less than 2 times the area of the first portion 242a in plan view. .

The vibrating piece 2 is composed of a Z-cut crystal plate. By configuring the vibrating piece 2 with crystal (Z-cut crystal plate), the vibration characteristics (particularly frequency-temperature characteristics) of the vibrating piece 2 can be made excellent. Further, the vibrating element 2 can be formed with high dimensional accuracy by etching. Quartz belongs to a trigonal system and has crystal axes such as an X-axis, a Y-axis, and a Z-axis that are orthogonal to each other. The X-axis, Y-axis, and Z-axis are called an electrical axis, a mechanical axis, and an optical axis, respectively. A Z-cut crystal plate is a plate-shaped crystal substrate that extends in the XY plane defined by the Y axis (mechanical axis) and the X axis (electrical axis) and has a thickness in the Z axis (optical axis) direction. It is. Here, the X-axis of the crystal forming the vibrating element 2 is parallel to the x-axis, the Y-axis is parallel to the y-axis, and the Z-axis is parallel to the z-axis.

Note that the vibrating piece 2 may be made of a piezoelectric material other than crystal. Examples of piezoelectric materials other than crystal include lithium tantalate, lithium niobate, lithium borate, and barium titanate. Furthermore, depending on the configuration of the vibrating element 2, the vibrating element 2 may be constructed of a crystal plate having a cut angle other than the Z cut. Further, the vibrating piece 2 may be made of a material other than a piezoelectric material (a material that does not have piezoelectricity), such as silicon. In this case, the detection arms 22, 23 and the drive arms 24, 25, 26 , 27 may be provided with a piezoelectric element (an element having a piezoelectric film made of PZT or the like sandwiched between a pair of electrodes).

An electrode film 4 is provided on the surface of the vibrating piece 2 configured in this manner. As shown in FIG. 2, this electrode film 4 includes a drive signal electrode 41, a drive ground electrode 42, a detection signal electrode 43, a detection ground electrode 44, and a plurality of electrodes electrically connected to these electrodes. It has a terminal (not shown).

The drive signal electrode 41 is an electrode for exciting drive vibrations of the drive arms 24, 25, 26, and 27. As shown in FIG. 2, the drive signal electrodes 41 are provided on the upper and lower surfaces of the arm portion 241 of the drive arm 24 and on both sides of the arm portion 261 of the drive arm 26, respectively. Similarly, although not shown, the drive signal electrodes 41 are provided on the upper and lower surfaces of the arm portion 251 of the drive arm 25 and on both sides of the arm portion 271 of the drive arm 27, respectively.

On the other hand, the drive ground electrode 42 has a reference potential (eg, ground potential) with respect to the drive signal electrode 41. As shown in FIG. 2, the driving ground electrodes 42 are provided on both sides of the arm portion 241 of the driving arm 24 and on the upper and lower surfaces of the arm portion 261 of the driving arm 26, respectively. Similarly, although not shown, the driving ground electrodes 42 are provided on both sides of the arm portion 251 of the driving arm 25 and on the upper and lower surfaces of the arm portion 271 of the driving arm 27, respectively.

The detection signal electrode 43 is an electrode for detecting charges generated by the detection vibration when the detection vibration of the detection arm 22 is excited. As shown in FIG. 2, the detection signal electrodes 43 are provided on the upper and lower surfaces of the arm portion 221 of the detection arm 22. As shown in FIG.

On the other hand, the detection ground electrode 44 has a reference potential (eg, ground potential) with respect to the detection signal electrode 43. As shown in FIG. 2, the detection ground electrodes 44 are provided on both sides of the arm portion 221 of the detection arm 22. As shown in FIG. Similarly, although not shown, the detection ground electrode 44 is provided on the upper and lower surfaces of the arm portion 231 of the detection arm 23.

Although not shown, detection signal electrodes for detecting charges generated by the detection vibration when the detection vibration of the detection arm 23 is excited are provided on the upper and lower surfaces of the arm portion 231 of the detection arm 23. There is. Similarly, the detection ground electrode of the detection arm 23 has a reference potential (for example, ground potential) with respect to the detection signal electrode of the detection arm 23, and is provided on both sides of the arm portion 231 of the detection arm 23. There is. Then, the vibration may be detected by a differential signal between the detection signal electrode 43 of the detection arm 22 and the detection signal electrode of the detection arm 23.

Although the constituent materials of the electrode film 4 are not particularly limited, for example, gold (Au), gold alloy, platinum (Pt), aluminum (Al), aluminum alloy, silver (Ag), silver alloy, chromium (Cr ), chromium alloy, copper (Cu), molybdenum (Mo), niobium (Nb), tungsten (W), iron (Fe), titanium (Ti), cobalt (Co), zinc (Zn), zirconium (Zr), etc. A transparent electrode material such as ITO, ZnO, etc. can be used, and among them, it is preferable to use a metal whose main material is gold (gold, gold alloy) or platinum. Note that a layer of Ti, Cr, etc. may be provided between the electrode film 4 and the vibrating element 2 as a base layer having a function of preventing the electrode film 4 from peeling off from the vibrating element 2.

Such an electrode film 4 has a portion disposed on the weight portions 222, 232, 242, 252, 262, and 272 of the vibrating piece 2 described above. The weight film 3 is placed on the weight portions 222, 232, 242, 252, 262, and 272 via the corresponding portions. Note that the electrode film 4 does not need to be placed directly under the weight film 3.

As shown in FIG. 1, the weight film 3 includes a weight film 31 placed on the weight part 222, a weight film 32 placed on the weight part 232, and a weight film 32 placed on the weight part 242. It has a membrane 33, a weight membrane 34 placed on the weight part 252, a weight membrane 35 placed on the weight part 262, and a weight membrane 36 placed on the weight part 272. The weight films 31 and 32 are films that can be used to adjust the resonance frequencies of the detection arms 22 and 23 by removing an appropriate amount with an energy beam such as a laser. Further, the weight films 33, 34, 35, and 36 are films that can be used to adjust the resonance frequencies of the drive arms 24, 25, 26, and 27 by removing an appropriate amount with energy rays such as a laser. be.

The weight film 33 is disposed on the second main surface 2b of the first main surface 2a (lower surface) and the second main surface 2b (upper surface) which are in the front and back relationship of the weight part 242, and is disposed on the second main surface 2b. is not placed in
Further, the weight film 33 is not arranged on the side surfaces (left and right side surfaces and tip surface) of the weight portion 242.
In this embodiment, the weight film 33 is provided over the entire width direction (x-axis direction) of the weight part 242, excluding a part of the base end side of the weight part 242. Therefore, the weight film 33 is disposed over the first portion 242a and the second portions 242b and 242c of the weight portion 242.

As shown in FIG. 4, the center of gravity G2 of the weight film 33 is the first principal surface 2a (lower surface) and It is located on the second main surface 2b side of the second main surface 2b (upper surface). By shifting the center of gravity G2 in the thickness direction with respect to the center C in this manner, it is possible to maintain balance with the weight portion 242 having the center of gravity G1 located on the opposite side of the center of gravity G2 of the weight film 33, as described above. can. Similar to such a weight film 33, the weight films 34, 35, and 36 have the front and back relationships of the weight portions 252, 262, and 272 with respect to the center C in the thickness direction of the drive arms 25, 26, and 27, respectively. It is located on the second main surface 2b side of the first main surface 2a (lower surface) and second main surface 2b (upper surface) located at . Further, the weight films 31 and 32 have a first main surface (lower surface) and a second main surface (lower surface) that are in the front and back relationship of the weight parts 222 and 232 with respect to the center in the thickness direction of the detection arms 22 and 23, respectively. It is located on the second main surface side of the upper surface).

Note that the positions, sizes, ranges, etc. of the weight membranes 31 to 36 are not limited to the positions, sizes, ranges, etc. shown in the drawings. For example, the weight film 3 may be arranged on the first main surface 2a and side surfaces of the weight portions 222, 232, 242, 252, 262, and 272. In this case, the thickness, arrangement, etc. of the weight films 33, 34, 35, and 36 other than the weight films 31 and 32 may be adjusted so that their center of gravity G2 is located on the second main surface 2b side. Further, the weight film 3 may be provided over the entire length of the weight portions 222, 232, 242, 252, 262, and 272 in the length direction (y-axis direction).

The constituent material of such a weight film 3 is not particularly limited, and for example, metals, inorganic compounds, resins, etc. can be used, but it is preferable to use metals or inorganic compounds. A film of a metal or an inorganic compound can be formed simply and with high precision by a vapor phase film forming method. Furthermore, the weight films 31 to 36 made of metal or inorganic compounds can be removed efficiently and with high precision by irradiation with an energy beam. For this reason, by forming the weight film 3 using a metal or an inorganic compound, the frequency adjustment described below becomes more efficient and accurate.

Examples of such metals include nickel (Ni), gold (Au), gold alloy, platinum (Pt), aluminum (Al), aluminum alloy, silver (Ag), silver alloy, chromium (Cr), chromium alloy, copper. (Cu), molybdenum (Mo), niobium (Nb), tungsten (W), iron (Fe), titanium (Ti), cobalt (Co), zinc (Zn), zirconium (Zr), etc. One kind or a combination of two or more kinds thereof can be used. Among them, from the viewpoint that the weight film 3 can be formed using the same apparatus as the electrode film 4, such metals include Al, Cr, Fe, Ni, Cu, Ag, Au, Pt, or at least one of these. It is preferable to use an alloy containing. More specifically, the weight film 3 preferably has a structure in which an upper layer made of Au (gold) is laminated on a base layer made of Cr (chromium), for example. This provides excellent adhesion to the vibrating piece 2 or the electrode film 4 formed using crystal, and allows the resonance frequency to be adjusted with high precision and efficiency.

In addition, such inorganic compounds include oxide ceramics such as alumina (aluminum oxide), silica (silicon oxide), titania (titanium oxide), zirconia, yttria, and calcium phosphate, silicon nitride, aluminum nitride, titanium nitride, and boron nitride. Examples include nitride ceramics, graphite, carbide ceramics such as tungsten carbide, and other ferroelectric materials such as barium titanate, strontium titanate, PZT, PLZT, and PLLZT, among others, silicon oxide (SiO ₂ ) It is preferable to use an insulating material such as titanium oxide (TiO ₂ ), aluminum oxide (Al ₂ O ₃ ), or the like.

Further, the thickness (average thickness) of the weight film 3 is not particularly limited, but is, for example, about 10 nm or more and 10,000 nm or less.

The vibrating element 1 configured as described above detects the angular velocity ω around the z-axis in the following manner. First, by applying a voltage (drive signal) between the drive signal electrode 41 and the drive ground electrode 42, the drive arm 24 and the drive arm 26 are moved toward and away from each other in the direction shown by arrow a in FIG. The bending vibrations (drive vibrations) are repeatedly caused, and the drive arms 25 and 27 are caused to repeatedly approach and separate from each other in the same direction as the bending vibrations (drive vibrations). At this time, if no angular velocity is applied to the vibrating element 1, the drive arms 24, 25 and the drive arms 26, 27 are vibrating plane symmetrically with respect to the yz plane passing through the center point (center of gravity G). The base body 211, the connecting arms 212, 213, and the detection arms 22, 23 hardly vibrate. At this time, as described above, the center of gravity G1 of the weight portions 242, 252, 262, 272 and the center of gravity G2 of the weight membranes 33, 34, 35, 36 are aligned with the center C of the drive arms 24, 25, 26, 27. Since the driving arms 24, 25, 26, and 27 are located on opposite sides, vibrations in the out-of-plane direction can be reduced.

When the driving arms 24 to 27 are driven to vibrate in this manner (drive mode), when an angular velocity ω around the normal line passing through the center of gravity G (that is, around the z-axis) is applied to the vibrating element 1, the driving arms 24 to 27 The Coriolis force acts on each of them. As a result, the connecting arms 212 and 213 bend and vibrate in the direction shown by the arrow b in FIG. 1, and along with this, the detection arms 22 and 23 bend in the direction shown by the arrow c in FIG. Vibrations (detected vibrations) are excited. Charges are generated between the detection signal electrode 43 and the detection ground electrode 44 due to such detection vibrations (detection mode) of the detection arms 22 and 23. Based on such charges, the angular velocity ω applied to the vibration element 1 can be determined.

As described above, the vibrating element 1 includes the base 21, the arms 241, 251, 261, and 271 that extend from the base 21, and the arms 241, 251, 261, and 271 at the tip. Drive arms 24, 25, 26, 27 which are vibrating arms having weights 242, 252, 262, 272 located on the sides, and weight membranes 33, 34 disposed on the weights 242, 252, 262, 272. , 35, 36. Here, the weight portions 242, 252, 262, and 272 have a first main surface 2a and a second main surface 2b that are in a front-back relationship. The center of gravity G1 of the weight parts 242, 252, 262, 272 is the center plane CP of the arm parts 241, 251, 261, 271 in the thickness direction (the center of the drive arms 24, 25, 26, 27 in the thickness direction). The plane passing through C and perpendicular to the z-axis) is located on the first principal surface 2a side. On the other hand, the center of gravity G2 of the weight membranes 33, 34, 35, and 36 is located closer to the second principal surface 2b than the center plane CP of the arm portions 241, 251, 261, and 271 in the thickness direction.

According to such a vibration element 1, the center of gravity G1 of the weight portions 242, 252, 262, 272 is located at a position closer to the first principal surface 2a than the center plane CP of the arm portions 241, 251, 261, 271 in the thickness direction. However, since the center of gravity G2 of the weight membranes 33, 34, 35, and 36 is located closer to the second principal surface 2b than the center plane CP of the arm portions 241, 251, 261, and 271 in the thickness direction, the weight portion The center of gravity of the entire structure consisting of 242, 252, 262, 272 and the weight membranes 33, 34, 35, 36 can be moved closer to the center plane CP (the center C of the drive arms 24, 25, 26, 27). Therefore, unnecessary vibrations (vibrations in the thickness direction) of the drive arms 24, 25, 26, and 27 can be reduced, and as a result, noise vibrations external to the vibration element 1 can be reduced. Further, although the manufacturing method will be described later, it is sufficient to arrange the weight films 33, 34, 35, and 36 only on one side of the weight portions 242, 252, 262, and 272 (specifically, on the second main surface 2b side). Therefore, the manufacturing process of the vibrating element 1 is simplified, and the droplets generated when adjusting the resonant frequency of the vibrating arm by removing part of the weight films 33, 34, 35, and 36 with an energy beam such as a laser can be eliminated. (dross) can also be reduced.

Furthermore, the centers of gravity G1 of the weights 242, 252, 262, and 272 are all located on the first main surface 2a side (the same side), and the centers of gravity G2 of the weights 33, 34, 35, and 36 are all located on the second main surface 2a side (the same side as each other). Since these weight portions 242, 252, 262, 272 and weight films 33, 34, 35, and 36 are located on the main surface side (on the same side), it is easy to form them. Note that one of the drive arms 24, 25, 26, and 27 corresponds to a "first vibrating arm" and the other one corresponds to a "second vibrating arm." The first vibrating arm has one of the arm parts 241, 251, 261, and 271 as a first arm part, and a weight part connected to the first arm part among the weight parts 242, 252, 262, and 272. section as the first weight section. The second vibrating arm has a weight portion different from the first weight portion among the arm portions 241, 251, 261, and 271 as a second arm portion, and a second arm portion among the weight portions 242, 252, 262, and 272. It has a weight part connected to as a second weight part. Further, on the first weight part, any one of the weight films 33, 34, 35, and 36 is arranged as a first weight film, and on the second weight part, one of the weight films 33, 34, 34, and 36 is arranged as a second weight film. Either 35 or 36 is arranged.

Here, it is preferable that the arm portions 241, 251, 261, and 271 each have a plane-symmetrical shape with respect to the central plane CP in the thickness direction. This makes it possible to reduce vibrations in the thickness direction due to the shapes of the drive arms 24, 25, 26, and 27.

The vibrating element 1 of this embodiment includes drive arms 24, 25, 26, 27 that drive and vibrate, and detection arms 22, 23 that deform in response to inertial force. and connecting arms 212 and 213 that are connecting parts extending from the base main body 211. The drive arms 24 , 25 , 26 , and 27 are vibrating arms and extend from the connecting arms 212 and 213 , and the detection arms 22 and 23 extend from the base body 211 . Thereby, the characteristics of the so-called double T-shaped vibration element 1 can be improved.

The width W of the weight portions 242, 252, 262, and 272 is larger than the width W0 of the arm portions 241, 251, 261, and 271 when viewed in plan from the thickness direction of the weight portion 242. Thereby, the area of the weight portions 242, 252, 262, 272 on which the weight films 33, 34, 35, 36 can be formed can be increased. Furthermore, the lengths of the driving arms 24, 25, 26, and 27 can be shortened, and as a result, the vibrating element 1 can be made smaller.

Further, the weight portion 242 includes a first portion 242a and second portions 242b and 242c that are thinner than the first portion 242a. The second main surface 2b has step-shaped steps 244 and 245 formed by the first portion 242a and the second portions 242b and 242c. Thereby, the center of gravity G1 of the weight portion 242 can be located closer to the first principal surface 2a than the center plane CP of the arm portion 241 in the thickness direction with a relatively simple configuration. Further, the weight portions 252, 262, and 272 are also configured similarly to the weight portion 242, and have similar effects. Here, the "step 244" means that the average distance from the center plane in the thickness direction of the weight part 242 in the first part 242a to the second main surface 2b is the center in the thickness direction of the weight part 242 in the second part 242b. The shape is larger than the average distance from the surface to the second principal surface 2b. "The central plane in the thickness direction of the weight part 242" is a surface perpendicular to the thickness direction of the weight part 242, and is the outermost part of the weight part 242 in the thickness direction on the first main surface 2a side. 2 Refers to a surface having the same distance from the outermost point in the thickness direction on the side of the main surface 2b. The thickness direction of the weight portion 242 and the thickness direction of the arm portion 241 are the same. In the illustration, the center plane of the weight portion 242 in the thickness direction and the center plane CP of the arm portion 241 in the thickness direction are on the same plane. Note that the step 245 is also defined similarly to the step 244.

Further, the steps 244 and 245 provided on the second main surface 2b described above are configured to include inclined surfaces, and the weight portion 242 is in the first portion 242a when viewed in plan from the thickness direction of the weight portion 242. and the second portions 242b, 242c, there is a portion where the thickness gradually decreases. Thereby, the weight film 33 can be easily formed continuously over the first portion 242a and the second portions 242b and 242c. Furthermore, cracks in the weight film 33 due to the steps 244, 245 between the first portion 242a and the second portions 242b, 242c can be reduced.
Further, the weight portions 252, 262, and 272 are also configured similarly to the weight portion 242, and have similar effects.

In this embodiment, the second portions 242b and 242c are arranged on both sides of the first portion 242a in the width direction of the drive arm 24 (vibrating arm). Thereby, the mass of both ends of the weight portion 242 in the width direction can be reduced, and the torsional moment of the drive arm 24 can be reduced. Further, the weight portions 252, 262, and 272 are also configured similarly to the weight portion 242, and have similar effects.

Further, the first main surface 2a of the weight portion 242 is a flat surface. Thereby, there is no need to process the first main surface 2a side of the weight portion 242 in order to provide the first portion 242a and the second portions 242b, 242c on the weight portion 242, and as a result, the manufacturing process of the vibration element 1 is simplified. can be converted into Further, the weight portions 252, 262, and 272 are also configured similarly to the weight portion 242, and have similar effects. Note that the first main surface 2a may have a step like the second main surface 2b, but since the center of gravity G1 is located as described above, the depth of the step on the first main surface 2a is as follows. It is preferable that the depth is shallower than the depth of the step on the second main surface 2b.

The weight film 33 is arranged on the first portion 242a and on the second portions 242b and 242c. Thereby, the mass of the weight film 33 can be increased. Furthermore, the formation of the weight film 33 can be simplified. Further, the weight films 34, 35, and 36 are also configured in the same manner as the weight film 33, and have similar effects. Note that the weight film 33 may be provided only on either one of the first portion 242a and the second portions 242b and 242c as long as the center of gravity G2 is at the position described above. Here, when the weight film 33 is provided only on the first portion 242a, the mass balance in the width direction of the drive arm 24 is better than when the weight film 33 is provided only on the second portions 242b and 242c. It has the advantage of being easy.

Further, although the thickness of the weight film 33 is shown to be uniform in the illustration, it may have a plurality of portions having mutually different thicknesses. That is, the weight film 33 may include a first weight film and a second weight film that is thinner than the first weight film. In this case, when adjusting the resonance frequency of the drive arm 24 by removing a part of the weight film 33 with an energy beam such as a laser, fine adjustment and coarse adjustment can be easily performed. Here, the thick first weight film has a large mass per unit area and is suitable for coarse adjustment of the resonance frequency of the drive arm 24. On the other hand, the thin second weight film has a small mass per unit area and is suitable for fine adjustment of the resonance frequency of the drive arm 24. Furthermore, the weight films 34, 35, and 36 can also have the same effect as the weight film 33.

In this embodiment, regarding the drive arms 24, 25, 26, 27, the center of gravity of the entire structure consisting of the weight portions 242, 252, 262, 272 and the weight membranes 33, 34, 35, 36 is set to the drive arms 24, 25, 26, 27. , 26, 27, the detection arms 22, 23 may be configured in the same manner as the drive arms 24, 25, 26, 27. In this case, the center planes of the arm parts 221 and 231 in the thickness direction are respectively defined similarly to the center plane of the arm part 241 in the thickness direction. The weight membranes 31 and 32 are each defined similarly to the weight membrane 33.

(Manufacturing method of vibration element)
Hereinafter, a method for manufacturing a vibrating element according to the present invention will be explained using an example of manufacturing the above-mentioned vibrating element 1.

FIG. 6 is a flowchart showing an example of a method for manufacturing a vibration element.
As shown in FIG. 6, the method for manufacturing the vibrating element 1 includes a vibrating element forming step S10, an electrode forming step S20, a weight film forming step S30, and a frequency adjusting step S40. Each step will be explained in sequence below.

- Vibration piece forming process S10 -
FIG. 7 is a cross-sectional view showing the step of preparing a substrate in the vibrating element forming step. FIG. 8 is a cross-sectional view showing a process of forming a corrosion-resistant film and a resist film in the vibrating element forming process. FIG. 9 is a cross-sectional view showing the process of forming the outer shape of the vibrating element in the vibrating element forming process. FIG. 10 is a cross-sectional view showing a step of removing a portion of the corrosion-resistant film in the vibrating element forming step. FIG. 11 is a cross-sectional view showing a step of forming a groove in the vibrating element forming step. FIG. 12 is a cross-sectional view showing the process of removing the corrosion-resistant film and the resist film in the vibrating element forming process. Note that FIGS. 7 to 12 show cross sections corresponding to FIG. 5.

First, the vibrating piece 2 is formed. Specifically, for example, first, as shown in FIG. 7, a crystal substrate 20 having a first main surface 2a and a second main surface 2b is prepared. Then, as shown in FIG. 8, corrosion-resistant films 51 and 52 and resist films 53 and 54 are sequentially formed on both surfaces of the crystal substrate 20.
Here, the corrosion-resistant films 51 and 52 are laminated films in which, for example, chromium and gold are laminated in this order by vapor deposition, sputtering, etc., and are resistant to etching solutions used in the outline forming process and groove forming process, which will be described later. , and is patterned to match the shape (outside shape) of the vibrating element 2 in plan view. The resist films 53 and 54 are each made of a resist material, and have resistance to etching liquid used in the outer shape forming step and the groove forming step, which will be described later. In addition, the groove 243 and the second portions 242b, 242c, etc. are patterned by exposure and development according to their planar shape.

Next, as shown in FIG. 9, by etching the crystal substrate 20 using the corrosion-resistant films 51 and 52 and the resist films 53 and 54 as masks, a crystal substrate 20A having the same external shape as the vibrating element 2 is obtained ( external shape formation process). Thereafter, as shown in FIG. 10, the corrosion-resistant film 52 is etched using the resist film 54 as a mask, thereby obtaining a corrosion-resistant film 52A. Then, as shown in FIG. 11, the quartz substrate 20A is etched using the corrosion-resistant films 51, 52A and the resist films 53, 54 as masks, and as shown in FIG. The vibrating element 2 is obtained by removing it by etching or the like (groove formation step).

Here, the vibrating piece 2 may be in a state (hereinafter also referred to as "wafer state") connected to another part of the crystal substrate 20A. In this wafer state, the vibrating piece 2 is connected to another portion of the crystal substrate 20A via a fragile break-off portion that is small in at least one of its width and thickness, for example. Furthermore, in a wafer state, a plurality of vibrating elements 1 can be formed at once on the crystal substrate 20A.

-Electrode formation step S20-
FIG. 13 is a cross-sectional view showing the electrode forming process.

As shown in FIG. 13, an electrode film 4 is formed. More specifically, a metal film is uniformly formed on the surface of the vibrating element 2 by, for example, sputtering. Then, a photoresist is applied, exposed and developed to obtain a resist mask, and then the exposed portions of the metal film from the resist mask are removed using an etching solution. Thereby, the electrode film 4 is formed.

- Weight film formation step S30 -
FIG. 14 is a cross-sectional view showing the weight film forming process.
As shown in FIG. 14, the weight film 3 is formed by mask vapor deposition or the like.

-Frequency adjustment step S40-
FIG. 15 is a cross-sectional view showing the frequency adjustment process.

As shown in FIG. 15, a part of the weight film 3 is removed using the energy beam LL, if necessary. More specifically, if necessary, parts of the weight membranes 33 to 36 are removed to adjust the frequency of drive vibration (of the drive arms 24 to 27) so that the resonance frequencies of the drive arms 24 to 27 are equal to each other. (resonant frequency). Further, if necessary, parts of the weight films 31 and 32 are removed to adjust the frequency of the detection vibration (resonance frequency of the detection arms 22 and 23).

As the energy beam LL, for example, a pulse laser such as YAG, YVO ₄ or excimer laser, continuous wave laser such as carbon dioxide laser, ion beam such as FIB (Focused Ion Beam) or IBF (Ion Beam Figuring) is used. be able to.

Such frequency adjustment step S40 may be performed in a wafer state, or may be performed in a state mounted in a package 11, which will be described later. Further, the frequency adjustment step S40 may be performed in multiple steps; for example, a rough adjustment is performed as the first adjustment in the wafer state, and a fine adjustment is performed as the second adjustment in the state mounted on the package 11. Good too.

As described above, the method for manufacturing the vibrating element 1 includes a base 21, a first principal surface 2a and a second principal surface 2b that extend from the base 21 and have a front and back relationship, and a The step of forming the drive arm 24 (vibration arm) with the center of gravity G1 located on the first main surface 2a side from the center plane (vibration piece formation step S10), and the step of forming the drive arm 24 in the thickness direction of the drive arm 24. The resonant frequency of the drive arm 24 is adjusted by forming the weight film 33 in which the center of gravity G2 is located on the second main surface 2b side from the central plane (weight film formation step S30) and adjusting the mass of the weight film 33. (frequency adjustment step S40). According to such a method of manufacturing the vibrating element 1, the characteristics of the resulting vibrating element 1 can be improved. Here, the "center plane of the drive arm 24 in the thickness direction" is a plane perpendicular to the thickness direction of the drive arm 24, and is the outermost plane in the thickness direction on the first main surface 2a side of the drive arm 24. This refers to a surface where the distance between the location and the outermost location in the thickness direction on the second main surface 2b side is equal. In this embodiment, an example has been described in which the mass of the weight film 33 is reduced and adjusted by removing a part of the weight film 33 with the energy beam LL. The mass of the weight film 33 may be increased and adjusted by forming the film using a film forming method. The same applies to the resonance frequencies of the other drive arms 25 to 27 and detection arms 22 and 23.

<Second embodiment>
FIG. 16 is an enlarged plan view showing a weight portion and a weight film of a vibrating arm (drive arm) of a vibrating element according to a second embodiment of the present invention. FIG. 17 is a sectional view taken along line CC in FIG. 16.

The second embodiment will be described below, focusing on the differences from the above-described embodiments, and omitting descriptions of similar matters. Note that in FIGS. 16 and 17, the same components as those in the embodiment described above are denoted by the same reference numerals. Furthermore, although one drive arm will be representatively explained below, the same applies to the other drive arms.

This embodiment is the same as the first embodiment described above, except that the configuration (shape) of the weight portion is different.

As shown in FIG. 16, the weight portion 242A of the drive arm 24A included in the vibrating element 1A of this embodiment has a first portion 242d connected to the arm portion 241, and a first portion 242d connected to the arm portion 241 with respect to the first portion 242d. has a second portion 242e located on the opposite side. As shown in FIG. 17, the thickness t2 of the second portion 242e is thinner than the thickness t1 of the first portion 242d. Here, the weight film 33 is disposed over the first portion 242d and the second portion 242e.

According to this embodiment as described above, the characteristics can be improved as well as in the first embodiment described above.

Further, in this embodiment, the second portion 242e is disposed on the opposite side of the base 21 with respect to the first portion 242d. Thereby, the second portion 242e is located at the tip of the drive arm 24A, which has a large mass effect, so that the area of the second portion 242e in plan view can be reduced. Another advantage is that the mass balance in the width direction of the weight portion 242A is less likely to collapse.

<Third embodiment>
FIG. 18 is an enlarged plan view showing a weight portion and a weight film of a vibrating arm (drive arm) of a vibrating element according to a third embodiment of the present invention.

The third embodiment will be described below, focusing on the differences from the above-described embodiments, and omitting descriptions of similar matters. Note that in FIG. 18, the same components as in the embodiment described above are designated by the same reference numerals. Furthermore, although one drive arm will be representatively explained below, the same applies to the other drive arms.

This embodiment is the same as the first embodiment described above, except that the configuration (shape) of the weight portion is different.

The weight portion 242B of the drive arm 24B included in the vibration element 1B of this embodiment has a form that is a combination of the first and second embodiments described above. That is, as shown in FIG. 18, the weight portion 242B includes a first portion 242f connected to the arm portion 241, and a second portion 242g on both sides and the tip side of the first portion 242f in the width direction. have The thickness of the second portion 242g is thinner than the thickness of the first portion 242f. Here, the weight film 33 is disposed over the first portion 242f and the second portion 242g.

According to this embodiment as described above, the characteristics can be improved as well as in the first embodiment described above.

<Fourth embodiment>
FIG. 19 is an enlarged plan view showing a weight portion and a weight film of a vibrating arm (drive arm) of a vibrating element according to a fourth embodiment of the present invention. FIG. 20 is a sectional view taken along line BB in FIG. 19.

The fourth embodiment will be described below, focusing on the differences from the above-described embodiments, and omitting descriptions of similar matters. Note that in FIGS. 19 and 20, the same components as those in the embodiment described above are denoted by the same reference numerals. Furthermore, although one drive arm will be representatively explained below, the same applies to the other drive arms.

This embodiment is the same as the first embodiment described above, except that the configuration (shape) of the weight portion is different.

As shown in FIG. 19, the weight portion 242C of the drive arm 24C included in the vibrating element 1C of this embodiment includes a frame-shaped first portion 242i connected to the arm portion 241, and a weight portion 242C located inside the first portion 242i. It has a second portion 242h. As shown in FIG. 20, the thickness t2 of the second portion 242h is thinner than the thickness t1 of the first portion 242i. Here, the weight film 33 is disposed across the first portion 242i and the second portion 242h in the width direction of the weight portion 242C.

According to this embodiment as described above, the characteristics can be improved as well as in the first embodiment described above.

Furthermore, in the present embodiment, the first portion 242i is provided surrounding the second portion 242h when viewed in plan from the thickness direction of the weight portion 242C. Such a second portion 242h is provided by forming a recess 247. The recess 247 can be formed by etching similarly to the groove 243 described above. Therefore, the design of the second portion 242h becomes easy.

<Fifth embodiment>
FIG. 21 is a plan view showing a vibration element according to a fifth embodiment of the present invention.

The fifth embodiment will be described below, focusing on the differences from the above-described embodiments, and omitting descriptions of similar matters.

This embodiment is similar to the first embodiment described above, except that the present invention is applied to a so-called H-type vibration element.

The vibration element 1D shown in FIG. 21 is a sensor element that detects angular velocity around the y-axis. This vibrating element 1D includes a vibrating piece 2D, an electrode film (not shown) provided on the vibrating piece 2D, and a weight film 3D.

The vibrating piece 2D has a base 21D, a pair of drive arms 24D, 25D, and a pair of detection arms 22D, 23D. These are integrally constructed using a Z-cut crystal plate. Note that the correspondence between the crystal axis of the crystal and the x-axis, y-axis, and z-axis is the same as in the first embodiment described above.

The base 21D is supported by a package 11, which will be described later.
Drive arms 24D and 25D each extend in the y-axis direction (+y direction) from base 21D. The drive arms 24D, 25D are configured similarly to the drive arms of any of the first to fourth embodiments described above. These drive arms 24D and 25D each have a pair of drives that bend and vibrate the drive arms 24D and 25D in the x-axis direction when energized, similarly to the drive arms 24 to 27 of the first embodiment described above, although not shown. Electrodes (a drive signal electrode and a drive ground electrode) are provided.
The pair of drive electrodes are electrically connected to terminals (not shown) on the base 21D via wiring (not shown).

The detection arms 22D and 23D each extend in the y-axis direction (-y direction) from the base 21D. Although not shown, each of the detection arms 22D and 23D includes a pair of detection electrodes (a detection signal electrode and a detection ground electrode) that detect charges generated due to bending vibration of the detection arms 22D and 23D in the z-axis direction. is provided. This pair of detection electrodes is electrically connected to a terminal (not shown) on the base 21D via wiring (not shown).

The weight films 3D include weight films 31D and 32D arranged on the tips (weight parts) of the detection arms 22D and 23D, and weight films 33D arranged on the tips (weight parts) of the drive arms 24D and 25D. , 34D.

In the vibrating element 1D configured in this way, by applying a drive signal between the pair of drive electrodes, the drive arm 24D and the drive arm 25D approach each other as shown by arrows A1 and A2 in FIG. The bending vibration (drive vibration) repeats the separation.

When the angular velocity ω around the y-axis is applied to the vibrating element 1D in a state where the drive arms 24D and 25D are driven and vibrated in this way, the drive arms 24D and 25D are moved by the Coriolis force as indicated by arrows B1 and B2 in FIG. , they bend in opposite directions in the z-axis direction. Accordingly, the detection arms 22D and 23D bend and vibrate (detection vibration) in opposite directions in the z-axis direction, as shown by arrows C1 and C2 in FIG.

Charges generated between the pair of detection electrodes due to such bending vibrations of the detection arms 22D and 23D are output from the pair of detection electrodes. Based on such charges, the angular velocity ω applied to the vibration element 1D can be determined.

According to this embodiment as described above, the characteristics can be improved as well as in the first embodiment described above.

Here, the vibration element 1D of this embodiment has drive arms 24D and 25D that extend from the base 21D and vibrate, and extend in the opposite direction from the base 21D to the drive arms 24D and 25D to cope with inertial force. The driving arms 24D and 25D are vibrating arms. Thereby, the characteristics of the so-called H-type vibration element 1D can be improved.

<Sixth embodiment>
FIG. 22 is a plan view showing a vibration element according to a sixth embodiment of the present invention.

The sixth embodiment will be described below, focusing on the differences from the above-described embodiments, and omitting descriptions of similar matters.

This embodiment is similar to the first embodiment described above, except that the present invention is applied to a so-called bipod tuning fork type vibrating element.

The vibration element 1E shown in FIG. 22 is a sensor element that detects angular velocity around the y-axis. This vibrating element 1E includes a vibrating piece 2E, an electrode film (not shown) provided on the vibrating piece 2E, and weight films 33E and 34E.

The vibrating piece 2E has a base 21E and a pair of vibrating arms 24E, 25E, which are integrally formed using a Z-cut crystal plate. Note that the correspondence between the crystal axis of the crystal and the x-axis, y-axis, and z-axis is the same as in the first embodiment described above.

The base 21E includes a first base 214 to which the vibrating arms 24E and 25E are connected, a second base 216 disposed on the opposite side of the first base 214 from the vibrating arms 24E and 25E, and a first base 216. 214 and a connecting portion 215 that connects the second base 216. The connecting portion 215 is located between the first base 214 and the second base 216, and has a smaller width (length in the x-axis direction) than the first base 214. Thereby, vibration leakage can be reduced while reducing the length of the base portion 21E along the y-axis direction. Here, the second base 216 is supported by, for example, the package 11 described later.

The vibrating arms 24E and 25E each extend in the y-axis direction (+y direction) from the base 21E. The vibrating arms 24E, 25E are configured similarly to the drive arms of any of the first to fourth embodiments described above. Each of the vibrating arms 24E and 25E has a pair of drives, which are not shown in the drawings, which bend and vibrate the vibrating arms 24E and 25E in the x-axis direction by applying electricity, similar to the drive arms 24 to 27 of the first embodiment described above. Electrodes (a drive signal electrode and a drive ground electrode) are provided.
The pair of drive electrodes are electrically connected to terminals (not shown) on the base 21E via wiring (not shown).

In addition to the pair of drive electrodes described above, each of the vibrating arms 24E and 25E has a pair of drive electrodes (not shown) for detecting electric charges generated as a result of the bending vibration of the vibrating arms 24E and 25E in the z-axis direction. Detection electrodes (detection signal electrode and detection ground electrode) are provided. This pair of detection electrodes are electrically connected to terminals (not shown) on the base 21E via wiring (not shown).

The weight films 33E, 34E are arranged on the tips (weight portions) of the vibrating arms 24E, 25E.
In the vibrating element 1E configured in this manner, by applying a drive signal between the pair of drive electrodes, the vibrating arm 24E and the vibrating arm 25E repeatedly approach and separate from each other to perform bending vibration (drive vibration). do.

When the vibrating arms 24E, 25E are driven to vibrate in this way, when an angular velocity ω around the y-axis is applied to the vibrating element 1E, the vibrating arms 24E, 25E are moved to opposite sides in the z-axis direction due to the Coriolis force. Bending vibrations are excited. Charges generated between the pair of detection electrodes due to the vibrations thus excited are output from the pair of detection electrodes. Based on such charges, the angular velocity ω applied to the vibration element 1E can be determined.

According to this embodiment as described above, the characteristics can be improved as well as in the first embodiment described above.

2. Physical Quantity Sensor FIG. 23 is a sectional view showing a physical quantity sensor according to an embodiment of the present invention.

The physical quantity sensor 10 shown in FIG. 23 is a vibrating gyro sensor that detects angular velocity around the z-axis. This physical quantity sensor 10 includes a vibration element 1 (or 1A, 1B, 1C, 1D, 1E), a support member 12, a circuit element 13 (integrated circuit chip), and a package 11 that houses these. There is.

The package 11 includes a box-shaped base 111 having a recess for housing the vibration element 1, and a plate-shaped lid 112 joined to the base 111 via a joining member 113 so as to close the opening of the recess of the base 111. have The inside of the package 11 may be in a reduced pressure (vacuum) state, or may be filled with an inert gas such as nitrogen, helium, or argon.

The recessed portion of the base 111 has an upper surface located on the opening side, a lower surface located on the bottom side, and a middle surface located between these surfaces. The constituent material of the base 111 is not particularly limited, but various ceramics such as aluminum oxide and various glass materials can be used. Further, the constituent material of the lid 112 is not particularly limited, but it is preferable that the material has a coefficient of linear expansion similar to that of the constituent material of the base 111. For example, when the constituent material of the base 111 is ceramic as described above, it is preferable to use an alloy such as Kovar.
Further, in this embodiment, a seam ring is used as the joining member 113, but the joining member 113 may be made of, for example, low melting point glass, adhesive, or the like.

A plurality of connection terminals 14 and 15 are provided on the upper and middle surfaces of the recessed portion of the base 111, respectively. Among the plurality of connection terminals 15 provided on the middle surface, some are electrically connected to terminals 16 provided on the bottom surface of the base 111 via a wiring layer (not shown) provided on the base 111. The remaining portions are electrically connected to a plurality of connection terminals 14 provided in the upper stage via wiring (not shown). These connection terminals 14 and 15 are not particularly limited as long as they have conductivity, but for example, a metallized layer (base layer) of Cr (chromium), W (tungsten), etc., Ni (nickel), Au (gold), etc. ), Ag (silver), Cu (copper), etc., are laminated together.

The circuit element 13 is fixed to the lower surface of the concave portion of the base 111 with an adhesive 19 or the like. As the adhesive 19, for example, an epoxy adhesive, a silicone adhesive, or a polyimide adhesive can be used. The circuit element 13 has a plurality of terminals (not shown), and each of the terminals is electrically connected to each of the connection terminals 15 provided on the middle surface described above by a conductive wire. This circuit element 13 includes a drive circuit for driving and vibrating the vibrating element 1, and a detection circuit for detecting the detected vibration generated in the vibrating element 1 when angular velocity is applied.

Furthermore, the support member 12 is connected to a plurality of connection terminals 14 provided on the upper surface of the recessed portion of the base 111 via a conductive adhesive 17. The support member 12 includes a wiring pattern 122 connected to the conductive adhesive 17 and a support substrate 121 supporting the wiring pattern 122. As the conductive adhesive 17, for example, an epoxy-based, silicone-based, or polyimide-based conductive adhesive mixed with a conductive substance such as a metal filler can be used.

The support substrate 121 has an opening in the center, and a plurality of long leads of the wiring pattern 122 extend into the opening. The vibrating element 1 is connected to the tips of these leads via conductive bumps 123.

Note that although the circuit element 13 is provided inside the package 11 in this embodiment, the circuit element 13 may be provided outside the package 11.

As described above, the physical quantity sensor 10 includes the vibration element 1 (or 1A, 1B, 1C, 1D, 1E) and the package 11 containing the vibration element 1 (or 1A, 1B, 1C, 1D, 1E). , is provided. According to such a physical quantity sensor 10, the sensor characteristics (for example, detection accuracy) of the physical quantity sensor 10 can be improved by utilizing the excellent characteristics of the vibration element 1 (or 1A, 1B, 1C, 1D, 1E). can.

3. Inertial Measurement Device FIG. 24 is an exploded perspective view showing an embodiment of the inertial measurement device of the present invention. FIG. 25 is a perspective view of a board included in the inertial measurement device shown in FIG. 24.

An inertial measurement unit (IMU) 2000 shown in FIG. 24 is a so-called 6-axis motion sensor, and is used by being attached to a moving object (object to be measured) such as a car or robot. Detect posture and behavior (inertial momentum).

This inertial measurement device 2000 includes an outer case 2100, a joining member 2200, and a sensor module 2300, and the sensor module 2300 is fitted (inserted) into the outer case 2100 with the joining member 2200 interposed therebetween. There is.

The outer case 2100 has a box shape, and two diagonal corners of the outer case 2100 are provided with screw holes 2110 for screwing onto the object to be measured.

The sensor module 2300 includes an inner case 2310 and a substrate 2320, and is housed inside the aforementioned outer case 2100 with the inner case 2310 supporting the substrate 2320. Here, the inner case 2310 is joined to the outer case 2100 with an adhesive or the like via a joining member 2200 (for example, a rubber packing). Furthermore, the inner case 2310 has a recess 2311 that functions as a storage space for components mounted on the board 2320, and an opening 2312 for exposing the connector 2330 provided on the board 2320 to the outside. The board 2320 is, for example, a multilayer wiring board, and is bonded to the inner case 2310 with an adhesive or the like.

As shown in FIG. 25, a connector 2330, angular velocity sensors 2340X, 2340Y, 2340Z, an acceleration sensor 2350, and a control IC 2360 are mounted on the board 2320.

Connector 2330 is electrically connected to an external device (not shown) and is used to transmit and receive electrical signals such as electric power and measurement data between the external device and inertial measurement device 2000.

The angular velocity sensor 2340X detects the angular velocity around the X-axis, the angular velocity sensor 2340Y detects the angular velocity around the Y-axis, and the angular velocity sensor 2340Z detects the angular velocity around the Z-axis. Here, the angular velocity sensors 2340X, 2340Y, and 2340Z are the physical quantity sensors 10 described above, respectively. Further, the acceleration sensor 2350 is, for example, an acceleration sensor formed using MEMS technology, and detects acceleration in each of the X-axis, Y-axis, and Z-axis directions.

The control IC 2360 is an MCU (Micro Controller Unit), has a built-in storage unit including a nonvolatile memory, an A/D converter, and the like, and controls each part of the inertial measurement device 2000. Here, the storage unit stores a program that defines the order and contents for detecting acceleration and angular velocity, a program that digitizes detected data and incorporates it into packet data, and accompanying data.

As described above, the inertial measurement device 2000 includes the physical quantity sensor 10 and the control IC 2360, which is a circuit electrically connected to the physical quantity sensor 10. According to such an inertial measurement device 2000, the excellent sensor characteristics of the physical quantity sensor 10 can be utilized to improve the characteristics (for example, measurement accuracy) of the inertial measurement device 2000.

4. Electronic Device FIG. 26 is a perspective view showing an embodiment of the electronic device (mobile type (or notebook type) personal computer) of the present invention.

In this figure, a personal computer 1100 includes a main body 1104 including a keyboard 1102 and a display unit 1106 including a display 1108. movably supported. Such a personal computer 1100 has a built-in inertial measurement device 2000 including the above-mentioned vibration element 1 (or 1A, 1B, 1C, 1D, 1E).

FIG. 27 is a plan view showing an embodiment of an electronic device (mobile phone) of the present invention.
In this figure, a mobile phone 1200 includes an antenna (not shown), a plurality of operation buttons 1202, an earpiece 1204 and a mouthpiece 1206, and a display section 1208 is located between the operation button 1202 and the earpiece 1204. It is located. Such a mobile phone 1200 has a built-in inertial measurement device 2000 including the above-mentioned vibration element 1 (or 1A, 1B, 1C, 1D, 1E).

FIG. 28 is a perspective view showing an embodiment of an electronic device (digital still camera) of the present invention.

A display unit 1310 is provided on the back of the case 1302 in the digital still camera 1300, and is configured to display information based on an imaging signal from a CCD.The display unit 1310 functions as a finder that displays the subject as an electronic image. . Further, on the front side (back side in the figure) of the case 1302, a light receiving unit 1304 including an optical lens (imaging optical system), a CCD, etc. is provided. Then, when the photographer confirms the subject image displayed on the display unit 1310 and presses the shutter button 1306, the CCD imaging signal at that time is transferred and stored in the memory 1308. Such a digital still camera 1300 has a built-in inertial measurement device 2000 that includes the above-mentioned vibration element 1 (or 1A, 1B, 1C, 1D, 1E), and the measurement results of this inertial measurement device 2000 are, for example, , used for image stabilization.

The electronic device as described above includes the vibration element 1 (or 1A, 1B, 1C, 1D, 1E). According to such an electronic device, the characteristics (for example, reliability) of the electronic device can be improved by utilizing the excellent characteristics of the vibration element 1 (or 1A, 1B, 1C, 1D, 1E).

In addition to the personal computer shown in FIG. 26, the mobile phone shown in FIG. 27, and the digital still camera shown in FIG. devices (e.g. inkjet printers), wearable terminals such as HMDs (head mounted displays), laptop personal computers, televisions, video cameras, video tape recorders, car navigation devices, pagers, electronic notebooks (including those with communication functions), electronic Dictionaries, calculators, electronic game devices, word processors, workstations, video phones, security TV monitors, electronic binoculars, POS terminals, medical equipment (e.g. electronic thermometers, blood pressure monitors, blood sugar meters, electrocardiogram measuring devices, ultrasound diagnostic devices, electronic The present invention can be applied to endoscopes), fish finders, various measuring instruments, instruments (for example, instruments for vehicles, aircraft, and ships), base stations for mobile terminals, flight simulators, and the like.

5. Mobile Object FIG. 29 is a perspective view showing an embodiment of the mobile object (automobile) of the present invention.

The automobile 1500 has a built-in inertial measurement device 2000 that includes the above-mentioned vibration element 1 (or 1A, 1B, 1C, 1D, 1E), and for example, the attitude of the vehicle body 1501 can be detected by the inertial measurement device 2000. can. The detection signal of the inertial measurement device 2000 is supplied to the vehicle body attitude control device 1502, and the vehicle body attitude control device 1502 detects the attitude of the vehicle body 1501 based on the signal, and controls the stiffness or softness of the suspension according to the detection result. , the brakes of individual wheels 1503 can be controlled.

Additionally, this kind of attitude control can be used in bipedal robots and radio-controlled helicopters (including drones). As described above, the inertial measurement device 2000 is incorporated in realizing attitude control of various moving bodies.

As described above, the automobile 1500, which is a moving object, includes the vibration element 1 (or 1A, 1B, 1C, 1D, 1E). According to such a car 1500, the characteristics (for example, reliability) of the car 1500 can be improved by utilizing the excellent characteristics of the vibration element 1 (or 1A, 1B, 1C, 1D, 1E).

Although the vibrating element, the method of manufacturing the vibrating element, the physical quantity sensor, the inertial measurement device, the electronic device, and the moving body of the present invention have been described above based on the illustrated embodiments, the present invention is not limited thereto. The configuration of each part can be replaced with any configuration having a similar function. Moreover, other arbitrary components may be added to the present invention.

Furthermore, in the embodiments described above, the vibrating element has a so-called double T-shape, H-shape, or bipedal tuning fork shape, but any element having vibrating arms that vibrate in the in-plane direction may be used. The shape is not limited, and may be of various shapes, such as a tripod tuning fork, orthogonal shape, or prismatic shape.

1... Vibration element, 1A... Vibration element, 1B... Vibration element, 1C... Vibration element, 1D... Vibration element, 1E... Vibration element, 2... Vibration piece, 2D... Vibration piece, 2E... Vibration piece, 2a... First main Surface, 2b... Second main surface, 3... Weight film, 3D... Weight film, 4... Electrode film, 10... Physical quantity sensor, 11... Package, 12... Supporting member, 13... Circuit element, 14... Connection terminal, 15... Connection terminal, 16...Terminal, 17...Conductive adhesive, 19...Adhesive, 20...Crystal substrate, 20A...Crystal substrate, 21...Base, 21D...Base, 21E...Base, 22...Detection arm, 22D...Detection arm , 23...detection arm, 23D...detection arm, 24...drive arm, 24A...drive arm, 24B...drive arm, 24C...drive arm, 24D...drive arm, 24E...vibration arm, 25...drive arm, 25D...drive arm , 25E... vibrating arm, 26... drive arm, 27... drive arm, 31... weight membrane, 31D... weight membrane, 32... weight membrane, 32D... weight membrane, 33... weight membrane, 33D... weight membrane, 33E... weight membrane , 34... weight film, 34D... weight film, 34E... weight film, 35... weight film, 36... weight film, 41... drive signal electrode, 42... drive ground electrode, 43... detection signal electrode, 44... detection ground electrode, 51... Corrosion resistant film, 52... Corrosion resistant film, 52A... Corrosion resistant film, 53... Resist film, 54... Resist film, 111... Base, 112... Lid, 113... Bonding member, 121... Support substrate, 122... Wiring pattern, 123... Bump, 211... Base body, 212... Connecting arm, 213... Connecting arm, 214... First base, 215... Connecting part, 216... Second base, 221... Arm part, 222... Weight part, 223... Groove, 231... Arm part, 232... Weight part, 233... Groove, 241... Arm part, 242... Weight part, 242A... Weight part, 242B... Weight part, 242C... Weight part, 242a... First part, 242b... Second part, 242c ...Second part, 242d...First part, 242e...Second part, 242f...First part, 242g...Second part, 242h...Second part, 242i...First part, 243...Groove, 244...Step, 245 ... step, 247 ... recess, 251 ... arm, 252 ... weight, 253 ... groove, 261 ... arm, 262 ... weight, 263 ... groove, 271 ... arm, 272 ... weight, 273 ... groove, 1100 ... Personal computer, 1102 ... Keyboard, 1104 ... Main body, 1106 ... Display unit, 1108 ... Display section, 1200 ... Mobile phone, 1202 ... Operation buttons, 1204 ... Earpiece, 1206 ... Mouthpiece, 1208 ... Display section, 1300 ...Digital still camera, 1302...Case, 1304...Light receiving unit, 1306...Shutter button, 1308...Memory, 1310...Display section, 1500...Car, 1501...Vehicle body, 1502...Vehicle body attitude control device, 1503...Wheel, 2000...Inertia Measuring device, 2100... Outer case, 2110... Screw hole, 2200... Joining member, 2300... Sensor module, 2310... Inner case, 2311... Recess, 2312... Opening, 2320... Board, 2330... Connector, 2340X... Angular velocity sensor, 2340Y...Angular velocity sensor, 2340Z...Angular velocity sensor, 2350...Acceleration sensor, 2360...Control IC, A1...Arrow, A2...Arrow, B1...Arrow, B2...Arrow, C...Center, C1...Arrow, C2...Arrow, G... Center of gravity, G1... Center of gravity, G2... Center of gravity, LL... Energy ray, S10... Vibrating element formation process, S20... Electrode formation process, S30... Weight film formation process, S40... Frequency adjustment process, a... Arrow, b... Arrow, c …arrow, ω…angular velocity

Claims (19)

The base and
a vibrating arm extending from the base and having an arm located on the base side and a weight part located on the distal end side of the arm;
a weight membrane disposed on the weight portion,
The weight portion has a first main surface and a second main surface that are in a front and back relationship,
The center of gravity of the weight portion is located at a position closer to the first main surface than the center plane in the thickness direction of the arm portion,
A vibration element characterized in that the center of gravity of the weight film is located closer to the second principal surface than the center plane in the thickness direction of the arm portion. The weight portion has a first portion and a second portion thinner than the first portion, and the second main surface has a stepped shape due to the first portion and the second portion. The vibration element according to claim 1. The vibration element according to claim 2, wherein the weight portion has a portion whose thickness gradually decreases between the first portion and the second portion when viewed in plan from the thickness direction of the weight portion. . The vibrating element according to claim 2 or 3, wherein the width of the weight portion is larger than the width of the arm portion in a plan view from the thickness direction. The vibrating element according to any one of claims 2 to 4, wherein the second portion is arranged on both sides of the vibrating arm in the width direction with respect to the first portion. The vibration element according to any one of claims 2 to 5, wherein the second portion is located on the opposite side of the base with respect to the first portion. The vibrating element according to any one of claims 2 to 4, wherein the first portion surrounds the second portion when viewed from above in the thickness direction of the weight portion. The vibrating element according to any one of claims 2 to 7, wherein the first main surface is a flat surface. The vibration element according to any one of claims 2 to 8, wherein the weight film is arranged on the first portion and the second portion. The vibrating element according to any one of claims 1 to 9, wherein the arm portion has a shape that is plane symmetrical with respect to a central plane in the thickness direction of the arm portion. a first vibrating arm that is the vibrating arm that extends from the base and has a first arm that is the arm, and a first weight that is the weight;
a second vibrating arm extending from the base and having a second arm located on the base side and a second weight part located on the distal end side of the second arm;
a first weight membrane that is the weight membrane disposed on the first weight part;
a second weight membrane disposed on the second weight part,
The center of gravity of the second weight portion is located at a position closer to the first main surface than the center plane in the thickness direction of the second arm portion,
The vibrating element according to any one of claims 1 to 10, wherein the center of gravity of the second weight film is located closer to the second main surface than the center plane in the thickness direction of the second arm. A driving arm that vibrates,
Equipped with a detection arm that deforms in response to inertial force,
The base includes a base body and a connecting portion extending from the base body,
The driving arm is the vibrating arm and extends from the connecting portion,
The vibrating element according to any one of claims 1 to 11, wherein the detection arm extends from the base main body. a drive arm extending from the base and driving and vibrating;
a detection arm extending from the base in a direction opposite to the drive arm and deforming in response to inertia;
The vibrating element according to any one of claims 1 to 11, wherein the driving arm is the vibrating arm. The vibration element according to any one of claims 1 to 13, wherein the weight film includes a first weight film and a second weight film thinner than the first weight film. a vibrating arm having a base, and a first principal surface and a second principal surface extending from the base, having a front-back relationship, and having a center of gravity located closer to the first principal surface than the central plane in the thickness direction; a step of forming;
forming a weight film on the vibrating arm, the center of gravity of which is located closer to the second main surface than the central plane of the vibrating arm in the thickness direction;
A method for manufacturing a vibrating element, comprising the step of adjusting the resonant frequency of the vibrating arm by adjusting the mass of the weight film. The vibration element according to any one of claims 1 to 14,
A physical quantity sensor comprising: a package housing the vibrating element. The physical quantity sensor according to claim 16;
An inertial measurement device comprising: a circuit electrically connected to the physical quantity sensor. An electronic device comprising the vibrating element according to any one of claims 1 to 14. A moving body comprising the vibration element according to any one of claims 1 to 14.

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