JP2012083112A - Physical quantity sensor element, physical quantity sensor, and electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a physical quantity sensor element that achieves excellent detection accuracy while being downsized, and to provide a reliable physical quantity sensor and an electronic device that include such physical quantity sensor element.SOLUTION: A physical quantity sensor element 1 includes: a drive portion 31 which can vibrate in an X-axis direction; a detection portion 34 which can vibrate in the X-axis direction together with the drive portion 31 and can also vibrate in a Z-axis direction relative to the drive portion 31; Y-axis direction extending portions 311 and 312 provided in the drive portion 31; drive electrodes 41 which are placed along the Y-axis direction extending portions 311 and 312 with respect to the Z-axis direction; and a detection electrode 51 which is placed so as to be separated from the detection portion 34 with respect to the Z-axis direction.

Description

  The present invention relates to a physical quantity sensor element, a physical quantity sensor, and an electronic apparatus.

  2. Description of the Related Art In recent years, angular velocity sensors that detect angular velocities are often used for camera shake correction of imaging devices such as digital cameras and attitude control of mobile navigation systems such as vehicles using GPS signals (see, for example, Patent Document 1). ).

  The angular velocity sensor of Patent Document 1 includes a drive unit that vibrates in the X-axis direction and a detection unit that is coupled to the drive unit via a beam and vibrates in the Y-axis direction orthogonal to the X-axis direction. Further, the angular velocity sensor of Patent Document 1 has a comb-tooth electrode, and vibrates the drive unit in the X-axis direction by an electrostatic force generated between the comb-tooth electrode and the drive unit.

  Moreover, in the angular velocity sensor of Patent Document 1, a plurality of X-axis direction extending portions extending in the X-axis direction are formed in the detection portion, and further, this portion is provided in a non-contact manner between a pair of fixed electrodes. ing.

  When an angular velocity around the Z-axis is applied with a voltage applied to the comb-shaped electrode and the drive unit vibrated in the X-axis direction, Coriolis force acts in the Y-axis direction and the detection unit vibrates in the Y-axis direction. . When the detector vibrates in the Y-axis direction, the gap (separation distance) between each fixed electrode and the X-axis extending portion changes, and the capacitance between each fixed electrode and the X-axis extending portion changes. Change. The angular velocity sensor of Patent Document 1 is configured to detect an angular velocity around the Z axis based on such a change in capacitance.

JP 2000-105124 A

  However, in the physical quantity sensor (angular velocity sensor) of Patent Document 1, since the comb electrode is provided outside the drive unit in order to vibrate the drive unit, the size of the apparatus is increased. Actually, in order to sufficiently vibrate the drive unit, more comb electrodes than those shown in the figure are required, and the size of the device becomes remarkable.

  Further, in the physical quantity sensor of Patent Document 1, the X-axis direction extending portion is positioned between the pair of fixed electrodes in order to detect a change in capacitance. In order to prevent pull-in between the fixed electrode and the X-axis extending portion due to the electrostatic force (suction force) generated between the fixed electrode and the X-axis extending portion, It must be secured relatively large, and the detection accuracy is reduced.

  Further, the drive unit and the detection unit are coupled so that the detection unit can be vibrated in the Y-axis direction by an electrostatic force (electrostatic spring) generated between the fixed electrode and the X-axis direction extension unit. The effective spring constant of the beam deviates from the mechanical spring constant. In other words, the effective spring constant of the beam is obtained by adding the electrostatic force to the mechanical spring constant of the beam. As a result, the relationship between the preset amount of displacement of the detector and the magnitude of the angular velocity deviates, and the angular velocity detection accuracy also decreases from this point.

  In particular, the tensile force of the beam that is generated when the detector is displaced has a linear relationship with the amount of displacement of the detector, whereas it is between the fixed electrode and the X-axis extending portion. The tensile force of the electrostatic spring formed on has a non-linear relationship with the amount of displacement of the detection unit. Therefore, a combination of these tensile forces, that is, an effective spring constant of the beam has a non-linear relationship with the displacement amount of the detection unit. As a result, the relationship between the “displacement amount of the detecting portion” and the “angular velocity magnitude” cannot be expressed by a linear proportional expression, and the angular velocity detection accuracy decreases, or the device configuration (circuit configuration) is reduced. To be complicated.

  As described above, the physical quantity sensor disclosed in Patent Document 1 has a problem that the apparatus is increased in size and the detection accuracy is lowered.

  An object of the present invention is to provide a physical quantity sensor element capable of exhibiting excellent detection accuracy while achieving downsizing, and a physical quantity sensor and an electronic apparatus having excellent reliability provided with the physical quantity sensor element. .

Such an object is achieved by the present invention described below.
In the physical quantity sensor element of the present invention, two axes orthogonal to each other are defined as a first axis and a second axis, and an axis parallel to the normal of the surface including the first axis and the second axis is defined as a third axis. When
A substrate,
A drive spring portion capable of vibrating in the first axial direction;
A drive unit connected to the drive spring unit;
One end of which is connected to the drive unit and is capable of vibrating in the third axial direction; and
A detection unit connected to the other end of the detection spring unit;
At least one driving conductive portion provided in the driving portion;
At least one detection conductive portion provided in the detection unit;
The drive unit is vibrated in the first axial direction by an electrostatic force that is disposed on the substrate and spaced apart from the drive conductive unit in the third axis direction and is generated between the drive conductive unit and the drive conductive unit. Driving electrodes to be
A detection electrode provided on the substrate so that a capacitance between the detection unit and the detection conductive unit is changed by displacement of the detection unit in the third axis direction. .
As a result, it is possible to provide a physical quantity sensor element that can exhibit excellent detection accuracy while achieving downsizing.

In the physical quantity sensor element of the present invention, the drive unit is vibrated in the first axis direction by the electrostatic force generated between the drive conductive unit and the drive electrode. When the angular velocity is applied, the detection unit receives Coriolis force and vibrates in the third axis direction with respect to the drive unit, and the capacitance between the detection conductive unit and the detection electrode generated by the vibration is increased. It is preferable to detect the angular velocity based on the change.
Thereby, a physical quantity sensor element can be used as an angular velocity sensor element.

In the physical quantity sensor element of the present invention, it is preferable that the drive conductive portion and the drive electrode are provided so as to extend in the second axial direction, respectively.
Thereby, a drive part can be vibrated to a 1st direction efficiently (with big force).
In the physical quantity sensor element of the present invention, the driving electrode has a pair of driving electrode pieces arranged to face each other in the first direction,
It is preferable that at least one of the driving electrode pieces is arranged so that a part thereof overlaps the driving electrode portion in a plan view having the third axis as a normal line.
Thereby, the electrostatic force for vibrating a drive part to a 1st direction can be generated efficiently.

In the physical quantity sensor element of the present invention, it is preferable that at least one of the drive electrode pieces has a width in the first axis direction larger than a maximum value of the amplitude of the drive unit.
Thereby, a drive part can be vibrated more smoothly in a 1st direction.
In the physical quantity sensor element of the present invention, it is preferable that one of the detection conductive portion and the detection electrode is disposed so as to cover the other in a plan view having the third axis as a normal line.
Thereby, it is possible to prevent or suppress the capacitance between the detection conductive portion and the detection electrode from changing due to the vibration in the first direction of the detection portion accompanying the vibration in the first direction of the drive portion.
In the physical quantity sensor element of the present invention, it is preferable that the driving unit has a frame shape, and the detection unit is disposed inside the driving unit.
Thereby, the arrangement of each part is optimized (a space can be used effectively), and the physical quantity sensor element can be downsized.

In the physical quantity sensor element of the present invention, two axes orthogonal to each other are defined as a first axis and a second axis, and an axis parallel to the normal of the surface including the first axis and the second axis is defined as a third axis. When
A substrate,
A detection spring portion capable of vibrating in the third axial direction;
A detection unit connected to the detection spring unit;
One end of the drive is connected to the detection unit, and the drive spring unit can vibrate in the first axial direction.
A drive unit connected to the other end of the drive spring unit;
At least one driving conductive portion provided in the driving portion;
At least one detection conductive portion provided in the detection unit;
The drive unit is vibrated in the first axial direction by an electrostatic force that is disposed on the substrate and spaced apart from the drive conductive unit in the third axis direction and is generated between the drive conductive unit and the drive conductive unit. Driving electrodes to be
A detection electrode provided on the substrate so that a capacitance between the detection unit and the detection conductive unit is changed by displacement of the detection unit in the third axis direction. .
As a result, it is possible to provide a physical quantity sensor element that can exhibit excellent detection accuracy while achieving downsizing.

The physical quantity sensor of the present invention comprises the physical quantity sensor element of the present invention and a package containing the physical quantity sensor element.
Thereby, the physical quantity sensor excellent in reliability can be provided.
An electronic apparatus according to the present invention includes the physical quantity sensor according to the present invention.
Accordingly, it is possible to provide electronic devices such as a mobile phone, a personal computer, and a digital camera that are excellent in reliability.

It is a top view which shows 1st Embodiment of the physical quantity sensor element of this invention. It is the sectional view on the AA line in FIG. It is sectional drawing for demonstrating the drive means which the physical quantity sensor element shown in FIG. 1 has. It is a figure which shows an example of the voltage applied when driving a physical quantity sensor. It is sectional drawing for demonstrating the effect | action of a drive means. It is a top view for demonstrating the effect | action of a detection means. It is sectional drawing which shows the physical quantity sensor (physical quantity sensor of this invention) provided with the physical quantity sensor element shown in FIG. It is a top view which shows 2nd Embodiment of the physical quantity sensor element of this invention. It is sectional drawing which shows 3rd Embodiment of the physical quantity sensor element of this invention. It is a top view which shows 4th Embodiment of the physical quantity sensor element of this invention. It is the BB sectional view taken on the line shown in FIG. It is a top view which shows 5th Embodiment of the physical quantity sensor element of this invention. 1 is a perspective view illustrating a configuration of a mobile (or notebook) personal computer to which an electronic device including a physical quantity sensor of the present invention is applied. It is a perspective view which shows the structure of the mobile telephone (PHS is also included) to which the electronic device provided with the physical quantity sensor of this invention is applied. It is a perspective view which shows the structure of the digital still camera to which the electronic device provided with the physical quantity sensor of this invention is applied.

Hereinafter, a physical quantity sensor element, a physical quantity sensor, and an electronic device of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.
<First Embodiment>
1 is a plan view showing a first embodiment of a physical quantity sensor element of the present invention, FIG. 2 is a cross-sectional view taken along the line AA in FIG. 1, and FIG. 3 is a driving means included in the physical quantity sensor element shown in FIG. FIG. 4 is a cross-sectional view for explaining the operation of the driving means, FIG. 5 is a cross-sectional view for explaining the action of the driving means, and FIG. FIG. 8 is a sectional view showing a physical quantity sensor (physical quantity sensor of the present invention) provided with the physical quantity sensor element shown in FIG.

  In each figure, for convenience of explanation, an X axis, a Y axis, and a Z axis are illustrated as three axes orthogonal to each other. In the following, the direction parallel to the X axis (first axis) is the “X axis direction”, the direction parallel to the Y axis (second axis) is the Y axis direction, and the direction is parallel to the Z axis (third axis). Is referred to as “Z-axis direction”. Further, in the following description, for convenience of explanation, the upper side in FIG. 1 is referred to as “upper”, the lower side is referred to as “lower”, the right side is referred to as “right”, and the left side is referred to as “left”. The right side is called “right” and the left side is called “left”.

1. Physical Quantity Sensor Element First, the physical quantity sensor element 1 will be described.
The physical quantity sensor element 1 of the present embodiment is an angular velocity sensor that detects an angular velocity around the Y axis.
As shown in FIG. 1, the physical quantity sensor element 1 includes a vibration system structure 3 provided in an XY plane, a substrate 2 that supports the vibration system structure 3, and a drive that vibrates the vibration system structure 3. Means 4 and detection means 5 for detecting an angular velocity around the Z axis are provided. Hereinafter, each of these units will be sequentially described in detail.

-Vibration system structure-
The vibration system structure 3 connects the frame-shaped drive unit 31, the support units 321, 322, 323, and 324 that support the drive unit 31, and the drive unit 31 and the support units 321, 322, 323, and 324. Drive spring portions 331, 332, 333, 334, a detection portion 34 provided inside the drive portion 31, and detection spring portions 351, 352, 353, 354 that connect the detection portion 34 and the drive portion 31, It consists of

  The vibration system structure 3 of the present embodiment is composed mainly of silicon, and uses a single silicon substrate (silicon wafer) by using various processing techniques (for example, etching techniques such as dry etching and wet etching). By processing into a desired outer shape, the drive unit 31, the support units 321, 322, 323, 324, the drive spring units 331, 332, 333, 334, the detection unit 34, and the detection spring units 351, 352, 353, 354 is integrally formed.

  By using silicon as the main material of the vibration system structure 3, excellent vibration characteristics can be realized and excellent durability can be exhibited. In addition, fine processing is possible, and the physical quantity sensor element 1 can be downsized. Further, by using silicon as the main material of the vibration system structure 3, the physical quantity sensor element 1 can be driven without forming electrodes on the vibration system structure 3 as will be described later. The structure can be made simpler.

The drive unit 31 has a frame shape in plan view with the Z axis as a normal line. Specifically, the drive unit 31 connects the pair of X-axis direction extending portions 313 and 314 extending in the X-axis direction and the Y-axis direction and connecting the X-axis direction extending portions 313 and 314. A pair of Y-axis direction extending portions (driving guide portions) 311 and 312 are included.
In addition, the shape of the drive part 31 is not limited to this, For example, the circular frame shape may be comprised and the shape which a part of frame lacked may be comprised.

The support portions 321, 322, 323, and 324 are arranged apart from each other along the periphery of the drive portion 31 in a plan view with the Z axis as a normal line. In the present embodiment, the support portions 321, 322, 323, and 324 are disposed corresponding to the corner portions of the drive portion 31, respectively. Such support portions 321, 322, 323, and 324 are respectively bonded to the substrate 2, whereby the vibration system structure 3 is supported by the substrate 2.
The drive spring portions 331, 332, 333, and 334 are configured so that the drive portion 31 can vibrate in the X-axis direction relative to the support portions 321, 322, 323, and 324. 324.

As shown in FIG. 1, the driving spring portion 331 connects the upper left corner portion of the driving portion 31 and the support portion 321, and the driving spring portion 332 includes the lower left corner portion of the driving portion 31 and the support portion 322. The driving spring portion 333 connects the lower right corner portion of the driving portion 31 and the support portion 323, and the driving spring portion 334 includes the upper right corner portion of the driving portion 31 and the support portion 324. Are connected.
By connecting the drive spring portions 331, 332, 333, and 334 to the four corners of the drive portion 31 in this way, the drive portion 31 can be supported in a stable state with respect to the support portions 321, 322, 323, and 324. it can.

  These drive spring portions 331, 332, 333, and 334 each have a meandering shape extending in the X-axis direction while reciprocating in the Y-axis direction. By forming the drive spring portions 331, 332, 333, and 334 in such a shape, the drive spring portions 331, 332, 333, and 334 are easily deformed (expanded) in the X-axis direction, and deformed in the Y-axis direction. It will be difficult. According to such driving spring portions 331, 332, 333, 334, the driving portion 31 can be vibrated accurately in the X-axis direction.

In particular, as in this embodiment, the length W ′ in the Y-axis direction is increased while the length L ′ in the X-axis direction of the drive spring portions 331, 332, 333, and 334 is shortened, that is, L ′. By setting <W ′, the above effect can be made more remarkable.
Further, the drive spring portions 331, 332, 333, and 334 are deformed in the Z-axis direction by relatively increasing the thickness (length in the Z-axis direction) of the drive spring portions 331, 332, 333, and 334. Thus, it is possible to prevent or suppress displacement of the drive unit 31 in the Z-axis direction. The thicknesses of the drive spring portions 331, 332, 333, and 334 can be appropriately set depending on the size (mass) of the vibration system structure 3.

  The detection unit 34 has a plate shape. The detection unit 34 is provided inside the drive unit 31. Thus, by arranging the detection unit 34 inside the drive unit 31, in other words, by providing the drive unit 31 so as to surround the detection unit 34, the arrangement of the drive unit 31 and the detection unit 34 is optimal. Therefore, the physical quantity sensor element 1 can be reduced in size.

As described above, the detection unit 34 of the present embodiment is composed of conductive silicon as a main material. Therefore, the detection unit 34 of the present embodiment also serves as a detection conductive unit that forms a capacitance with the detection electrode 51 of the detection unit 5 described later.
The detection springs 351, 352, 353, and 354 connect the detection unit 34 and the drive unit 31 so that the detection unit 34 can vibrate in the Z-axis direction with respect to the drive unit 31.

As shown in FIG. 1, the detection spring portion 351 connects the upper left corner of the detection unit 34 and the drive unit 31, and the detection spring unit 352 includes the lower left corner of the detection unit 34 and the drive unit 31. The detection spring portion 353 connects the lower right corner of the detection unit 34 and the drive unit 31, and the detection spring unit 354 includes the upper right corner of the detection unit 34 and the drive unit 31. Are connected.
Thus, by connecting the detection spring portions 351, 352, 353, and 354 to the four corners of the detection portion 34, the detection portion 34 can be supported (connected) in a stable state with respect to the drive portion 31.

  Each of the detection spring portions 351 and 353 has a meandering shape extending in the Y-axis direction while reciprocating in the X-axis direction. By forming the detection spring portions 351 and 353 in such a shape, deformation of the detection spring portions 351 and 353 in the X-axis direction can be prevented or suppressed. In addition, since the entire length of the detection spring portions 351 and 353 can be increased, the detection spring portions 351 and 353 are easily deformed in the Z-axis direction.

Each of the detection spring portions 352 and 354 has a meandering shape extending in the X-axis direction while reciprocating in the Y-axis direction. By forming the detection spring portions 352 and 354 in such a shape, deformation of the detection spring portions 352 and 354 in the Y-axis direction can be prevented or suppressed. Further, since the total length of the detection spring portions 352 and 354 can be increased, the detection spring portions 352 and 354 are easily deformed in the Z-axis direction.
By configuring the detection springs 351, 352, 353, and 354 as described above, the detection unit 34 can be configured while preventing or suppressing vibrations of the detection unit 34 in the X-axis direction and the Y-axis direction with respect to the drive unit 31. The drive unit 31 can be vibrated in the Z-axis direction. Therefore, the physical quantity sensor element 1 having excellent detection characteristics is obtained.

-Board-
The substrate 2 supports the vibration system structure 3. As shown in FIG. 2, the substrate 2 has a plate shape and is provided in the XY plane. The vibration system structure 3 is fixed and supported on the substrate 2 by bonding the support portions 321, 322, 323, and 324 of the vibration system structure 3 to the upper surface of the substrate 2.

The bonding method of the substrate 2 and the support portions 321, 322, 323, and 324 is not particularly limited, and may be bonded using a support member such as an adhesive, depending on the constituent material of the vibration system structure 3 and the substrate 2. Alternatively, bonding may be performed using various bonding methods such as direct bonding and anodic bonding.
A recess 21 is formed on the upper surface of the substrate 2 (the surface on the side facing the vibration system structure 3). The concave portion 21 is a portion of the substrate 2 and the vibration system structure 3 that actually vibrates (the drive unit 31, the drive spring units 331, 332, 333, 334, the detection unit 34, and the detection spring units 351, 352, 353, 354) has a function of preventing contact.

  The substrate 2 having such a configuration is composed of, for example, various types of glass as a main material, and is formed by processing a single glass plate into a desired outer shape using various processing techniques. The substrate 2 may be composed mainly of insulating materials such as various ceramic materials such as oxide ceramics, nitride ceramics, carbide-based ceramics, various resin materials such as polyimide, or silicon as the main material. It may be configured as. When silicon is used as the main material, it is preferable to perform necessary insulation treatment.

-Driving means-
As shown in FIG. 1, the drive unit 4 has a function of causing the drive unit 31 to vibrate in the X-axis direction together with the detection unit 34. Such a driving means 4 has a plurality (two in this embodiment) of driving electrodes 41 including a pair of driving electrode pieces 411 and 412. One of the two driving electrodes 41 is provided corresponding to the Y-axis direction extending part 311 of the driving part 31, and the other is provided corresponding to the Y-axis direction extending part 312.

Hereinafter, each of the drive electrodes 41 will be described. Since these have the same configuration, the drive electrode 41 provided corresponding to the Y-axis direction extending portion 311 will be described below as a representative. The description of the drive electrode 41 provided corresponding to the Y-axis direction extending portion 312 is omitted.
The pair of driving electrode pieces 411 and 412 are formed on the upper surface of the substrate 2 so as to be separated from each other in the X-axis direction.

The driving electrode pieces 411 and 412 are positioned below the Y-axis direction extending portion 311, and a gap is formed between the Y-axis direction extending portion 311 and the driving electrode pieces 411 and 412. . In other words, the drive electrode pieces 411 and 412 are disposed apart from the Y-axis direction extending portion 311 in the Z-axis direction.
The driving electrode pieces 411 and 412 are provided to face the axis Y ′ of the Y-axis direction extending portion 311 in the X-axis direction in a plan view with the Z-axis as a normal line. In the present embodiment, the drive electrode pieces 411 and 412 are provided symmetrically with respect to the axis Y ′.

Each of the driving electrode pieces 411 and 412 has a strip shape (long shape) extending in the Y-axis direction. The drive electrode pieces 411 and 412 are formed to have substantially the same length as the length of the Y-axis extending portion 311, and the Y of the Y-axis extending portion 311 is viewed in a plan view with the Z axis as a normal line. It is provided corresponding to the entire axial direction.
Further, as shown in FIG. 3, the driving electrode piece 411 is provided so that a part thereof overlaps with the Y-axis direction extending portion 311 in a plan view with the Z axis as a normal line. Specifically, the right side portion 411 a of the driving electrode piece 411 in FIG. 2 overlaps the Y-axis direction extending portion 311, and the left side portion 411 b is exposed from the Y-axis direction extending portion 311.

Similarly, the drive electrode piece 412 is also provided so that a part thereof overlaps with the Y-axis direction extending portion 311 in a plan view with the Z axis as a normal line. Specifically, the left side portion 412a of the driving electrode piece 412 in FIG. 3 overlaps the Y-axis direction extending portion 311 and the right side portion 412b is exposed from the Y-axis direction extending portion 311.
By arranging the driving electrode pieces 411 and 412 in this way, as will be described later, the electrostatic force indicated by arrows A and B in FIG. It can be vibrated in the axial direction.

  The width (length in the X-axis direction) a of the drive electrode pieces 411 and 412 is not particularly limited, but the maximum value of the amplitude of the drive unit 31 (non-drive state indicated by a solid line in FIG. 3 and vibration indicated by a chain line) It is preferable that it is larger than the movement distance (b) with the state at the time when the direction is switched. As a result, even when the drive unit 31 is vibrated, it is possible to maintain a state in which at least a part of the drive electrode pieces 411 and 412 overlaps the drive unit 31, so that an electrostatic force described later is efficiently applied to the drive unit 31. be able to.

The constituent material of the drive electrodes 411 and 412 is not particularly limited as long as it has conductivity. 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 It can be formed of a metal material such as (Zn) or zirconium (Zr), or an electrode material such as ITO or ZnO.
Such a drive means 4 vibrates the drive part 31 to a X-axis direction as follows, for example.

  For example, the voltage V1 shown in FIG. 4A is applied to the vibration system structure 3 (Y-axis direction extending portions 311 and 312) by a voltage applying means (not shown), and the driving electrode pieces 411 are shown in FIG. The first alternating voltage V2 having a sine wave shape shown in FIG. 2 is applied, and the second alternating voltage V3 having a sine wave shape shown in FIG. The second alternating voltage V3 is obtained by shifting the phase of the first alternating voltage V2 by 180 ° C.

As shown in FIG. 5, when such voltages V1, V2, and V3 are applied to the physical quantity sensor element 1, the electrostatic force indicated by the arrow A is generated in the Y-axis direction extending portions 311 and 312; The state in which the electrostatic force indicated by B is alternately switched, so that the drive springs 331, 332, 333, and 334 are elastically deformed, and the drive unit 31 and the detection unit 34 are sine waves in the X-axis direction. Vibrate.
As described above, the detection unit 34 positioned inside the drive unit 31 is restricted from displacement in the X-axis direction and the Y-axis direction with respect to the drive unit 31 by the detection spring units 351, 352, 353, and 354. Therefore, when the drive unit 31 vibrates in the X-axis direction, the positional relationship between the drive unit 31 and the detection unit 34 is maintained substantially constant.

  According to such a driving method, the spring constant of the electrostatic spring that can be formed by the electrostatic force (adsorptive force) generated between the Y-axis direction extending portion 311 and the driving electrodes 411 and 412 is set to zero. Therefore, the effective spring constant of the drive spring portions 331, 332, 333, and 334 can be made equal to the mechanical spring constant. That is, according to the physical quantity sensor element 1, the drive unit 31 can be vibrated without being affected by the electrostatic force generated between the Y-axis direction extending portion 311 and the drive electrode pieces 411 and 412. Therefore, it is possible to prevent a decrease in angular velocity detection accuracy.

In the present embodiment, as described above, the Y-axis direction extending portions 311 and 312 and the drive electrode pieces 411 and 412 are both provided extending in the Y-axis direction. Electric power can be increased. As a result, the drive unit 31 can be efficiently vibrated in the X-axis direction.
The frequencies of the first alternating voltage V2 and the second alternating voltage V3 are not particularly limited, but include the drive unit 31 (the detection unit 34 that vibrates integrally with the drive unit 31 and the detection spring units 351, 352, 353, and 354). And a resonance frequency of a vibration member constituted by the drive spring portions 331, 332, 333, and 334 is preferable. Thereby, the drive part 31 can be vibrated largely and smoothly in the X-axis direction.

  Here, when the voltages applied to the vibration system structure 3 and the drive electrode pieces 411 and 412 are the same, the arrow A increases as the gap g between the Y-axis direction extending portion 311 and the drive electrode pieces 411 and 412 decreases. , B can increase the electrostatic force. However, if the gap g is reduced, the Y-axis direction extending portion 311 is caused to move to the driving electrode piece 411 by the electrostatic force (adsorption force) generated between the Y-axis direction extending portion 311 and the driving electrode pieces 411 and 412. There is a risk of pull-in on 412.

Therefore, in the physical quantity sensor element 1, as described above, the drive spring portions 331, 332, 333, and 334 are made relatively thick so as to restrict (prevent) displacement of the drive portion 31 in the Z-axis direction. In addition, the Y-axis direction extending portion 311 as described above can be effectively prevented or suppressed from being attracted to the driving electrode pieces 411 and 412 and the gap g can be further reduced. As a result, the physical quantity sensor element 1 can efficiently vibrate the drive unit 31 in the X-axis direction, and can achieve downsizing and power saving of the apparatus.
The gap g is not particularly limited, but is preferably about 0.1 μm or more and 0.5 μm or less. According to such a range, it is possible to more reliably prevent the Y-axis direction extending portion 311 from being attracted to the driving electrode pieces 411 and 412 while increasing the electrostatic force indicated by the arrows A and B.

-Detection means-
The detecting means 5 has a function of detecting an angular velocity around the Z axis applied to the physical quantity sensor element 1. The detection unit 5 includes a detection electrode 51 provided apart from the detection unit 34 in the Z-axis direction.
The detection electrode 51 is provided so as to overlap the central portion excluding the edge portion of the detection unit 34 in a plan view with the Z axis as a normal line. The separation distance d in the X-axis direction b between the edge portion of the detection electrode 51 and the edge portion of the detection electrode is not particularly limited, but the maximum value of the amplitude of the driving portion 31 (non-driving state indicated by a solid line in FIG. 3) And the movement distance (b) at the time when the vibration direction indicated by the chain line changes.
Thereby, even if the detection unit 34 vibrates in the X-axis direction as the drive unit 31 vibrates in the X-axis direction, the area of the portion of the detection electrode 51 that overlaps the detection unit 34 does not change. Therefore, it is possible to prevent a change in capacitance between the detection unit 34 and the detection electrode 51 due to the vibration of the detection unit 34 in the X-axis direction.

  The constituent material of the detection electrode 51 is not particularly limited as long as it has conductivity. 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) or other metal material, or ITO or ZnO or other electrode material.

Such detection means 5 detects, for example, an angular velocity applied to the physical quantity sensor element 1 around the Z axis as follows.
First, as described above, the drive unit 4 causes the drive unit 31 to vibrate in the X-axis direction together with the detection unit 34 as described above. In this state, when an angular velocity around the Y axis is applied, a Coriolis force is generated in the Z axis direction orthogonal to the X axis and the Y axis, and vibration in the Z axis direction is excited. Accordingly, the detection unit 34 vibrates (displaces) in the Z-axis direction with respect to the drive unit 31 while elastically deforming the detection spring units 351, 352, 353, and 354 in the Z-axis direction.

  As a result, the separation distance between the detection unit 34 and the detection electrode 51 changes, and the capacitance between the detection unit 34 and the detection electrode 51 changes. Specifically, as shown in FIG. 6A, when the angular velocity around the Y axis is not applied to the physical quantity sensor element 1 and the detection unit 34 does not vibrate in the Z axis direction with respect to the drive unit 31. It is assumed that the electrostatic capacitance between the detection unit 34 and the detection electrode 51 is C.

On the other hand, as shown in FIG. 6B, when the detection unit 34 is displaced in the direction away from the detection electrode 51 due to the vibration of the detection unit 34 due to the Coriolis force, the separation distance is changed. By increasing the length, the capacitance between the detection unit 34 and the detection electrode 51 decreases to (C−ΔC). On the contrary, as shown in FIG. 6C, when the detection unit 34 is displaced in a direction approaching the detection electrode 51, the capacitance between the detection unit 34 and the detection electrode 51 is reduced to (C + ΔC). To do.
An angular velocity around the Y axis applied to the physical quantity sensor element 1 is detected by detecting such a change in capacitance between the detection unit 34 and the detection electrode 51 by a detection circuit (not shown).

  In the physical quantity sensor element 1 configured as described above, the driving electrode 41 can be provided at a position shifted in the Z-axis direction with respect to the vibration system structure 3 and to overlap the vibration system structure 3. In addition, the detection electrode 51 can also be provided at a position shifted in the Z-axis direction with respect to the vibration system structure 3 so as to overlap the vibration system structure 3. Therefore, according to the physical quantity sensor element 1, it is possible to reduce the size of the apparatus. Further, as described above, since the vibration system structure 3 can be vibrated without being affected by the electrostatic spring, excellent detection accuracy can be exhibited.

2. Physical Quantity Sensor Next, the physical quantity sensor 10 will be described.
As shown in FIG. 7, the physical quantity sensor 10 includes a package 6 and two physical quantity sensor elements 1 housed in the package 6.
The package 6 includes a base substrate 61 that also serves as the substrate 2 of each physical quantity sensor element 1, a frame-shaped frame member 62, and a plate-shaped lid member 63. The base substrate 61 and the frame member 62, and the frame member 62 and the lid member 63 are joined by an adhesive or a brazing material.

The base substrate 61 is made of the same material as that of the substrate 2 described above. The frame member 62 and the lid member 63 are made of, for example, the same constituent material as the base substrate 61, various metal materials such as Al and Cu, various glass materials, and the like.
In the physical quantity sensor 10, two physical quantity sensor elements 1 are provided side by side in the X-axis direction. In such a physical quantity sensor 10, the driving unit 31 included in one physical quantity sensor element 1 and the driving unit 31 included in the other physical quantity sensor element 1 are driven so as to vibrate in opposite phases in the X-axis direction. That is, the two drive units 31 are driven so as to alternately repeat a state in which the two drive units 31 are displaced in a direction approaching each other in the X-axis direction and a state in which the two drive units 31 are displaced in directions away from each other in the X-axis direction. According to such driving, leakage vibrations generated by the two driving units 31 can be canceled with each other. As a result, vibration leakage can be prevented and the physical quantity sensor 10 having excellent vibration characteristics is obtained.

<Second Embodiment>
FIG. 8 is a plan view showing a second embodiment of the physical quantity sensor element of the present invention.
In the following description, for convenience of explanation, the upper side in FIG. 8 is referred to as “upper”, the lower side as “lower”, the right side as “right”, and the left side as “left”.
The physical quantity sensor element of the present embodiment will be described with a focus on differences from the above-described embodiment, and description of similar matters will be omitted.
The physical quantity sensor element 1A of the present embodiment is the same as the physical quantity sensor element of the first embodiment described above except that the positional relationship between the drive unit and the detection unit is reversed. In FIG. 8, the same components as those in the first embodiment described above are denoted by the same reference numerals.

1. Physical quantity sensor element-Vibration system structure-
As shown in FIG. 8, the vibration system structure 3A includes a frame-shaped detection unit 34A, support units 321A, 322A, 323A, and 324A that support the detection unit 34A, a detection unit 34A, and support units 321A and 322A, Detection springs 351A, 352A, 353A, 354A for connecting 323A, 324A, a drive unit 31A provided inside the detection unit 34A, and a drive spring unit 331A for connecting the drive unit 31A and the detection unit 34A. 332A, 333A, 334A.

The detector 34A has a frame shape in plan view with the Z axis as a normal.
The support portions 321A, 322A, 323A, and 324A are spaced apart from each other along the periphery of the detection portion 34A in a plan view with the Z axis as a normal line. In the present embodiment, the support portions 321A, 322A, 323A, and 324A are arranged corresponding to the corner portions of the detection portion 34A, respectively. The support portions 321 </ b> A, 322 </ b> A, 323 </ b> A, and 324 </ b> A are bonded to the substrate 2, whereby the vibration system structure 3 is supported by the substrate 2.
The detection spring portions 351A, 352A, 353A, and 354A are configured so that the detection portion 34A can vibrate in the Z-axis direction with respect to the support portions 321A, 322A, 323A, and 324A. 323A and 324A are connected.

  As shown in FIG. 8, the detection spring portion 351A connects the upper left corner portion of the detection portion 34A and the support portion 321A, and the detection spring portion 352A includes the lower left corner portion of the detection portion 34A and the support portion 322. The detection spring portion 353A connects the lower right corner portion of the detection portion 34A and the support portion 323A, and the detection spring portion 354A includes the upper right corner portion of the detection portion 34A and the support portion 324A. Are connected. Thus, by connecting the detection spring portions 351A, 352A, 353A, 354A to the four corners of the detection portion 34A, the detection portion 34A can be supported in a stable state with respect to the support portions 321A, 322A, 323A, 324A. it can.

  Each of the detection spring portions 351A and 353A has a meandering shape extending in the Y-axis direction while reciprocating in the X-axis direction. By forming the detection spring portions 351A and 353A in such a shape, deformation of the detection spring portions 351A and 353A in the X-axis direction can be prevented or suppressed. Further, since the total length of the detection spring portions 351A and 353A can be increased, the detection spring portions 351A and 353A are easily deformed in the Z-axis direction.

  Each of the detection spring portions 352A and 354A has a meandering shape extending in the X-axis direction while reciprocating in the Y-axis direction. By forming the detection spring portions 352A and 354A in such a shape, deformation of the detection spring portions 352A and 354A in the Y-axis direction can be prevented or suppressed. Further, since the total length of the detection spring portions 352A and 354A can be increased, the detection spring portions 352A and 354A are easily deformed in the Z-axis direction.

  By configuring the detection spring portions 351A, 352A, 353A, and 354A as described above, vibrations in the X-axis direction and the Y-axis direction with respect to the support portions 321A, 322A, 323A, and 324A of the detection portion 34A are prevented or suppressed. Meanwhile, the detection unit 34A can be vibrated in the Z-axis direction with respect to the support units 321A, 322A, 323A, and 324A. Therefore, the physical quantity sensor element 1A has excellent detection characteristics.

  The drive unit 31A is provided inside the detection unit 34A. Thus, by arranging the drive unit 31A inside the detection unit 34A, in other words, by providing the detection unit 34A so as to surround the drive unit 31A, the arrangement of the drive unit 31A and the detection unit 34A is optimal. Therefore, the physical quantity sensor element 1A can be reduced in size.

Such a drive unit 31A includes a frame-shaped base 311A and a plurality of Y-axis direction extending parts (drive conductive parts) 312A provided inside the base 311A. The plurality of Y-axis direction extending portions 312 are provided side by side in the X-axis direction at intervals.
The drive springs 331A, 332A, 333A, and 334A connect the drive unit 31A and the detection unit 34A so that the drive unit 31A can vibrate in the X-axis direction with respect to the detection unit 34A.

  As shown in FIG. 8, the driving spring portion 331A connects the upper left corner of the driving portion 31 and the detection portion 34A, and the driving spring portion 332A includes the lower left corner of the driving portion 31 and the detection portion 34A. The driving spring portion 333A connects the lower right corner portion of the driving portion 31A and the detection portion 34A, and the driving spring portion 334A includes the upper right corner portion of the driving portion 31 and the detection portion 34A. Are connected. Thus, by connecting the drive spring portions 331A, 332A, 333A, and 334A to the four corners of the drive portion 31A, the drive portion 31A can be supported in a stable state with respect to the detection portion 34A.

  Each of the drive spring portions 331A, 332A, 333A, 334A has a meandering shape extending in the X-axis direction while reciprocating in the Y-axis direction. By making the driving spring portions 331A, 332A, 333A, and 334A into such a shape, each of the driving spring portions 331A, 332A, 333A, and 334A is easily deformed in the X-axis direction and difficult to deform in the Y-axis direction. It becomes. According to such driving spring portions 331A, 332A, 333A, and 334A, the driving portion 31A can be vibrated accurately in the X-axis direction.

-Driving means-
The drive means 4A has a plurality of drive electrodes 41A including a pair of drive electrode pieces 411A and 412A. 41 A of drive electrodes are provided corresponding to the Y-axis direction extension part 312A which the drive part 31A has, ie, the same number as the Y-axis direction extension part 312A.
Hereinafter, a plurality of drive electrodes 41A will be described. Since these have the same configuration, one drive electrode 41A will be representatively described below, and the other drive electrodes 41A will be described. Is omitted.

The driving electrode pieces 411A and 412A are provided on the upper surface of the substrate 2 so as to be separated from each other in the X-axis direction. The driving electrode pieces 411A and 412A are positioned below the Y-axis direction extending portion 312A, and a gap is formed between the Y-axis direction extending portion 312A and the driving electrode pieces 411A and 412A. Yes. The driving electrode pieces 411A and 412A are provided so as to face the axis Y ″ of the Y-axis direction extending portion 312A in the X-axis direction in a plan view with the Z-axis as a normal line.
Further, the drive electrode piece 411A is provided so that a part thereof overlaps with the Y-axis direction extending portion 312A in a plan view with the Z-axis as a normal line. Specifically, in plan view with the Z axis as a normal line, the right portion of the drive electrode piece 411A overlaps with the Y-axis extending portion 312A, and the left portion is the Y-axis extending portion 312A. Is exposed from.

Similarly, the driving electrode piece 412A is also provided so that a part thereof overlaps with the Y-axis direction extending portion 312A in a plan view with the Z axis as a normal line. Specifically, in a plan view with the Z axis as a normal line, the left portion of the drive electrode piece 412A overlaps with the Y axis extending portion 312A, and the right portion is the Y axis extending portion 312A. Is exposed from.
Similar to the first embodiment described above, such a driving unit 4A is configured to elastically deform the driving spring portions 331A, 332A, 333A, and 334A in the X-axis direction while moving the driving portion 31A relative to the detection portion 34A. Vibrate in the X-axis direction.

-Detection means-
The detection means 5A has a detection electrode 34A having a frame shape that is provided apart from the detection unit 34A in the Z-axis direction. The detection electrode 51A is provided so as to overlap the detection unit 34A in plan view with the Z axis as a normal line.
Such detection means 5A detects the angular velocity around the Y axis applied to the physical quantity sensor element 1A in the same manner as in the first embodiment described above.

<Third Embodiment>
FIG. 9 is a cross-sectional view showing a third embodiment of the physical quantity sensor element of the present invention.
The physical quantity sensor element of the present embodiment will be described with a focus on differences from the above-described embodiment, and description of similar matters will be omitted.
The physical quantity sensor element 1B of the present embodiment is the same as the physical quantity sensor element of the first embodiment described above, except that the configuration of the drive means and the detection means is different. In FIG. 9, the same components as those in the first embodiment described above are denoted by the same reference numerals.

As illustrated in FIG. 9, the physical quantity sensor element 1 </ b> B includes a vibration system structure 3 and a pair of substrates 2 and 7 that are disposed to face each other in the Z-axis direction with the vibration system structure 3 interposed therebetween. The substrate 7 has the same configuration as the substrate 2.
Driving electrodes 41 (driving electrode pieces 411 and 412) included in the driving unit 4 are provided on the substrates 2 and 7. That is, as shown in FIG. 9, the pair of drive electrodes 41 are disposed to face each other in the Z-axis direction via the Y-axis direction extending portion 311. Similarly, a pair of driving electrodes 41 are arranged to face each other in the Z-axis direction via the Y-axis direction extending portion 312.

  By configuring the driving unit 4 in such a configuration, when the driving unit 31 is vibrated in the X-axis direction by the driving unit 4, the driving unit 41 is provided between the driving electrode 41 provided on the substrate 2 and the Y-axis direction extending unit 311. The acting electrostatic force (adsorptive force) in the Z-axis direction cancels out the electrostatic force (adsorptive force) in the Z-axis direction acting between the drive electrode 41 provided on the substrate 7 and the Y-axis direction extending portion 311. It is possible to prevent or suppress the adsorption of the Y-axis direction extending portion 311 with the driving electrode 41 more reliably. The same applies to the Y-axis direction extending portion 312.

Further, electrostatic forces (forces indicated by arrows A and B in FIG. 5) for moving the Y-axis direction extending portion 311 in the Z-axis direction are applied to both sides of the Y-axis direction extending portion 311 in the Z-axis direction (substrate 2 side). Therefore, the drive unit 31 can be vibrated in the X-axis direction more stably and smoothly.
Further, as shown in FIG. 9, the detection electrode 51 included in the detection means 5 is provided on each of the substrates 2 and 7. That is, the pair of detection electrodes 51 are disposed to face each other in the Z-axis direction via the detection unit 34.

By configuring the detection means 5 in such a configuration, a change in capacitance between the detection electrode 51 on the substrate 2 side and the detection unit 34 and between the detection electrode 51 on the substrate 7 side and the detection unit 34 are performed. Based on the change in capacitance, the angular velocity around the Y axis can be detected with higher accuracy.
The physical quantity sensor incorporating the physical quantity sensor element 1B configured as described above is configured such that the base substrate 61 of the physical quantity sensor 10 described in the first embodiment described above also serves as the substrate 2 and the lid member 63 also serves as the substrate 7. It is preferable to do this. Thereby, the configuration of the physical quantity sensor is simplified.
According to the third embodiment, the same effect as that of the first embodiment described above can be obtained.

<Fourth embodiment>
10 is a plan view showing a fourth embodiment of the physical quantity sensor element of the present invention, and FIG. 11 is a cross-sectional view taken along line BB shown in FIG.
The physical quantity sensor element of the present embodiment will be described with a focus on differences from the above-described embodiment, and description of similar matters will be omitted.
The physical quantity sensor element 1C of the present embodiment is the same as the physical quantity sensor element of the first embodiment described above except that the configurations of the detection unit and the detection means are different. 10 and 11, the same reference numerals are given to the same components as those in the first embodiment described above.

As shown in FIG. 10, the detection unit 34C of the physical quantity sensor element 1C includes a frame-shaped base 341C and a plurality of X-axis direction extending parts (detection conductive parts) 342C provided inside the base 341C. Has been. The plurality of X-axis direction extending portions 342C are provided side by side in the Y-axis direction with an interval therebetween.
As shown in FIG. 11, the detection means 5C has a plurality of detection electrodes 51C. Each of the detection electrodes 51C is provided so as to extend in the X-axis direction and project in the Z-axis direction. Then, in the plan view with the Z axis as a normal line, one X-axis direction extending portion 342C is provided between a pair of adjacent detection electrodes 51C. Further, the detection electrode 51C is provided so that the tip thereof is positioned at the substantially center of the X-axis direction extending portion 342C in the Z-axis direction in a natural state where the detection portion 34C is not vibrating in the Z-axis direction. Yes.

Such a detecting means 5C detects the angular velocity around the Y axis as follows, for example.
First, the drive unit 4 vibrates the drive unit 31 in the X-axis direction. In this state, when an angular velocity around the Y-axis is applied to the physical quantity sensor element 1C, a Coriolis force is generated in the Z-axis direction, whereby a new vibration in the Z-axis direction is excited, and the detection unit 34C is detected by the detection spring unit. While 351, 352, 353, and 354 are elastically deformed in the Z-axis direction, the drive unit 31 vibrates in the Z-axis direction.

  Accordingly, the X-axis direction extending portion 342C vibrates in the Z-axis direction and is displaced in the Z-axis direction with respect to the detection electrode 51C. Then, the area of the portion where each of the detection electrodes 51C and the X-axis direction extending portion 342C overlap in the Y-axis direction changes, and accordingly, the capacitance between them also changes. Based on such a change in capacitance, the angular velocity applied in the Y-axis direction can be detected.

In particular, in the present embodiment, the tip of the detection electrode 51C is positioned substantially at the center in the Z-axis direction of the X-axis extending portion 342C in a natural state where the detection unit 34 does not vibrate in the Z-axis direction. Therefore, even if the detection unit 34C is displaced in any direction in the Z-axis direction (a direction away from the substrate 2 and a direction approaching the substrate 2), each detection electrode 51C and the X-axis extension portion 342C are in the Y-direction. Since the state of overlapping in the axial direction can be more reliably maintained, the change in capacitance as described above can be detected more accurately.
Also according to the fourth embodiment, the same effects as those of the first embodiment described above can be obtained.

<Fifth Embodiment>
FIG. 12 is a plan view showing a fifth embodiment of the physical quantity sensor element of the present invention.
The physical quantity sensor element of the present embodiment will be described with a focus on differences from the above-described embodiment, and description of similar matters will be omitted.
The physical quantity sensor element 1D of the present embodiment is the same as the physical quantity sensor element of the first embodiment described above, except that the configuration of the detection spring part and the vibration of the detection part associated therewith are different. In FIG. 12, the same reference numerals are given to the same components as those in the first embodiment described above.

  As illustrated in FIG. 12, the physical quantity sensor element 1 </ b> D includes two detection spring portions 351 </ b> D and 352 </ b> D that connect the detection unit 34 and the drive unit 31. Each of the detection spring portions 351D and 352D extends in the X-axis direction. The detection spring portions 351D and 352D are provided coaxially with each other. The axis X1 of the detection spring portions 351D and 352D is in the Y-axis direction with respect to the axis X2 that intersects the center of gravity (center) G of the detection portion 34 and is parallel to the X-axis in plan view with the Z axis as a normal line It is separated. In the present embodiment, the detection spring portion 351D connects the lower left corner of the detection unit 34 and the drive unit 31, and the detection spring unit 352D includes the lower right corner of the detection unit 34 and the drive unit 31. Are connected.

The detection part 34 connected to the drive part 31 by such detection spring parts 351D and 352D can rotate around the axis X1 while twisting and deforming the detection spring parts 351D and 352D, that is, in the Z-axis direction. Can be vibrated. When an angular velocity about the Y axis is applied to the physical force sensor element 1D with the drive unit 31 oscillating in the X axis direction, the detection unit 34 twists and deforms the detection springs 351D and 352D around the axis X1. It rotates, and the electrostatic capacitance between the detection part 34 and the electrode 51 for a detection changes by this. The angular velocity around the Y axis can also be detected based on such a change in capacitance.
Also according to the fourth embodiment, the same effects as those of the first embodiment described above can be obtained.
The resonator element of each embodiment as described above can be applied to various electronic devices, and the obtained electronic device has high reliability.

Here, an electronic device including the physical quantity sensor of the present invention will be described in detail with reference to FIGS.
FIG. 13 is a perspective view illustrating a configuration of a mobile (or notebook) personal computer to which an electronic device including the physical quantity sensor of the present invention is applied.
In this figure, a personal computer 1100 includes a main body portion 1104 provided with a keyboard 1102 and a display unit 1106 provided with a display portion 100. The display unit 1106 is rotated with respect to the main body portion 1104 via a hinge structure portion. It is supported movably.
Such a personal computer 1100 incorporates a physical quantity sensor 10 that functions as angular velocity detection means (gyro sensor).

FIG. 14 is a perspective view showing a configuration of a mobile phone (including PHS) to which an electronic device including the physical quantity sensor of the present invention is applied.
In this figure, a cellular phone 1200 includes a plurality of operation buttons 1202, an earpiece 1204, and a mouthpiece 1206, and the display unit 100 is disposed between the operation buttons 1202 and the earpiece 1204.
Such a cellular phone 1200 incorporates a physical quantity sensor 10 that functions as an angular velocity detection means (gyro sensor).

FIG. 15 is a perspective view showing a configuration of a digital still camera to which an electronic device including the physical quantity sensor of the present invention is applied. In this figure, connection with an external device is also simply shown.
Here, an ordinary camera sensitizes a silver halide photographic film with a light image of a subject, whereas a digital still camera 1300 photoelectrically converts a light image of a subject with an imaging device such as a CCD (Charge Coupled Device). An imaging signal (image signal) is generated.

A display unit is provided on the back of a case (body) 1302 in the digital still camera 1300, and is configured to perform display based on an imaging signal from the CCD. The display unit is a finder that displays an object as an electronic image. Function.
A light receiving unit 1304 including an optical lens (imaging optical system), a CCD, and the like is provided on the front side (the back side in the drawing) of the case 1302.

When the photographer confirms the subject image displayed on the display unit and presses the shutter button 1306, the CCD image pickup signal at that time is transferred and stored in the memory 1308.
In the digital still camera 1300, a video signal output terminal 1312 and an input / output terminal 1314 for data communication are provided on the side surface of the case 1302. As shown in the figure, a television monitor 1430 is connected to the video signal output terminal 1312 and a personal computer 1440 is connected to the input / output terminal 1314 for data communication as necessary. Further, the imaging signal stored in the memory 1308 is output to the television monitor 1430 or the personal computer 1440 by a predetermined operation.

Such a digital still camera 1300 incorporates a physical quantity sensor 10 that functions as angular velocity detection means (gyro sensor).
In addition to the personal computer (mobile personal computer) shown in FIG. 13, the mobile phone shown in FIG. 14, and the digital still camera shown in FIG. Inkjet printers), 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, televisions Telephone, crime prevention TV monitor, electronic binoculars, POS terminal, medical equipment (for example, electronic thermometer, blood pressure monitor, blood glucose meter, electrocardiogram measuring device, ultrasonic diagnostic device, electronic endoscope), fish detector, various measuring devices, instruments Type (e.g., vehicle, Sky machine, gauges of a ship), can be applied to a flight simulator or the like.

  As described above, the physical quantity sensor, the frequency adjustment method, the vibrator, the vibration device, and the electronic apparatus of the present invention have been described based on the illustrated embodiment, but the present invention is not limited to this, and the configuration of each unit is as follows. Any structure having a similar function can be substituted. Moreover, in the said Example, although the example which irradiates an energy beam to the 1st mass part or the 2nd mass part and performed frequency adjustment was demonstrated, it is not restricted to this, and mass is obtained by ion etching, sandblasting, and wet etching. You may reduce the mass of a part. The frequency may be adjusted by increasing the mass of the mass part by attaching a film to the first mass part or the second mass part by sputtering or vapor deposition. In addition, any other component may be added to the present invention. Further, the present invention may be a combination of any two or more configurations (features) of the above embodiments.

  Further, in the above-described embodiment, the vibration system structure has been described in which the main material is silicon. However, the main material of the vibration system structure is not limited to silicon, and may be, for example, various types of glass. Good. When the vibration system structure is composed of glass as a main material, a driving conductive portion in the form of a thin film made of a conductive material (for example, a metal material) is provided on the surface on the driving electrode side of each Y-axis extending portion. It is necessary to form and form a thin-film detection conductive portion made of a conductive material (for example, a metal material) on the surface on the detection electrode side of each X-axis extending portion.

  In the first and third embodiments described above, only one Y-axis extending portion is provided on each of one side and the other side in the X-axis direction with respect to the detection unit. The number of installed direction extending portions (drive conductive portions) is not limited to this. For example, a plurality of direction extending portions (drive conductive portions) may be provided on one side and the other side in the X-axis direction with respect to the detection unit. As the number of Y-axis direction extending portions increases, the drive unit can be vibrated in the X-axis direction with a stronger force.

  In the second embodiment described above, only one X-axis extending portion is provided on each of one side and the other side in the Y-axis direction with respect to the drive unit. The number of installed parts (detecting conductive parts) is not limited to this, and, for example, a plurality of parts may be provided on one side and the other side in the Y-axis direction with respect to the drive unit. As the number of extending portions in the X-axis direction increases, the change in capacitance increases, so that the angular velocity can be detected more accurately.

In the above-described embodiment, the configuration in which a part of the driving electrode piece overlaps the Y-axis direction extending portion and the Z-axis direction has been described. However, if the electrostatic force as described above can be generated, For example, the driving electrode piece may not overlap the Y-axis direction extending portion.
In the first embodiment described above, the configuration in which the detection electrode is arranged so as to overlap the central portion excluding the edge of the detection unit in a plan view with the Z axis as a normal line has been described. The arrangement of the detection electrode is not particularly limited as long as a capacitance is generated between the detection conductive portion) and the detection electrode. For example, the detection electrode may be arranged so that the outer shape (edge) of the detection electrode matches the outer shape (edge) of the detection unit in plan view with the Z axis as the normal line. Further, the detection electrode may be arranged so that the edge of the detection electrode is exposed (protruded) from the detection unit.
In the above-described embodiment, the physical quantity sensor element is used as an angular velocity sensor that detects angular velocity. However, the present invention is not limited to this. For example, the physical quantity sensor element may be used as an acceleration sensor that detects acceleration.

  DESCRIPTION OF SYMBOLS 1 ... Physical quantity sensor element 1A ... Physical quantity sensor element 1B ... Physical quantity sensor element 1C ... Physical quantity sensor element 1D ... Physical quantity sensor element 10 ... Physical quantity sensor 2 ... Substrate 21 ... Recess 3 ... Vibration system structure 3A ... Vibration system structure 31 ... Drive part 31A ... Drive part 311 ... Y-axis direction extension part 311A ... Base part 312 ... Y-axis direction extension part 312A ... Y-axis direction extension part 313 ... ... X-axis extension part 314 ... X-axis extension part 321 ... Support part 321A ... Support part 322 ... Support part 322A ... Support part 323 ... Support part 323A ... Support part 324 ... Support 324A ··· Supporting portion 331 · · · Spring portion for driving 331A · · · Spring portion for driving 332 · · · Spring portion for driving 332A · · · Spring portion for driving 333 · · · Spring for driving 333A ··· Drive spring portion 334 ··· Drive spring portion 334A ··· Drive spring portion 34 ··· Detection portion 34A ··· Detection portion 34C ··· Detection portion 341C ··· Base portion 342C ··· Extension portion 351 ...... Detection spring part 351A ... Detection spring part 351D ... Detection spring part 352 ... Detection spring part 352A ... Detection spring part 352D ... Detection spring part 353 ... Detection spring part 353A ... · · · Detection spring portion 354 · · · Detection spring portion 354A · · · Detection spring portion 4 · · · Drive means 4A · · · Drive means 41 · · · Electrode for drive 41A · · · Electrode for drive 411 · · · Electrode piece for drive 411a ··· Part 411b ... Part 411A ... Drive electrode piece 412a ... Part 412b ... Part 412 ... Drive electrode piece 412A ... Drive electrode piece 5 ... Detection Means 5A ... Detection means 5C ... Detection means 51 ... Detection electrode 51A ... Detection electrode 51C ... Detection electrode 6 ... Package 61 ... Base substrate 62 ... Frame member 63 ... Lid member 7 ... Substrate 100 Display unit 1100 Personal computer 1102 Keyboard 1104 Main unit 1106 Display unit 1200 Mobile phone 1202 Operation button 1204 Earpiece 1206 Speaker 1300 Digital still camera 1302 ... Case 1304 ... Light receiving unit 1306 ... Shutter button 1308 ... Memory 1312 ... Video signal output terminal 1314 ... Input / output terminal 1430 ... Television monitor 1440 ... Personal computer V1 ... Voltage V2 ... ...... First police box Pressure V3 ‥‥ second alternating voltage X1 ‥‥ axis X2 ‥‥ axis Y '‥‥ axis Y "‥‥ axis

Claims (10)

When two axes orthogonal to each other are defined as a first axis and a second axis, and an axis parallel to the normal of the surface including the first axis and the second axis is defined as a third axis,
A substrate,
A drive spring portion capable of vibrating in the first axial direction;
A drive unit connected to the drive spring unit;
One end of which is connected to the drive unit and is capable of vibrating in the third axial direction; and
A detection unit connected to the other end of the detection spring unit;
At least one driving conductive portion provided in the driving portion;
At least one detection conductive portion provided in the detection unit;
The drive unit is vibrated in the first axial direction by an electrostatic force that is disposed on the substrate and spaced apart from the drive conductive unit in the third axis direction and is generated between the drive conductive unit and the drive conductive unit. Driving electrodes to be
A detection electrode provided on the substrate so that a capacitance between the detection unit and the detection conductive unit is changed by displacement of the detection unit in the third axis direction. Physical quantity sensor element.   When an angular velocity around the second axis is applied in a state where the driving unit is vibrated in the first axial direction by the electrostatic force generated between the driving conductive unit and the driving electrode, a Coriolis force is generated. In response, the detection unit vibrates in the third axial direction with respect to the drive unit, and the angular velocity is determined based on a change in capacitance between the detection conductive unit and the detection electrode caused by the vibration. The physical quantity sensor element according to claim 1, wherein the physical quantity sensor element is detected.   3. The physical quantity sensor element according to claim 1, wherein each of the driving conductive portion and the driving electrode is provided so as to extend in the second axis direction. The driving electrode has a pair of driving electrode pieces arranged to face each other in the first direction,
The at least one of the said drive electrode pieces is arrange | positioned so that a part may overlap with the said drive electrode part by planar view which uses the said 3rd axis as a normal line. The physical quantity sensor element according to any one of the above.   5. The physical quantity sensor element according to claim 4, wherein at least one of the driving electrode pieces has a width in the first axis direction larger than a maximum amplitude value of the driving unit.   6. The detection conductive portion and the detection electrode are disposed so as to cover the other in plan view with the third axis as a normal line. The physical quantity sensor element according to 1.   The physical quantity sensor element according to any one of claims 1 to 6, wherein the driving unit has a frame shape, and the detection unit is disposed inside the driving unit. When two axes orthogonal to each other are defined as a first axis and a second axis, and an axis parallel to the normal of the surface including the first axis and the second axis is defined as a third axis,
A substrate,
A detection spring portion capable of vibrating in the third axial direction;
A detection unit connected to the detection spring unit;
One end of the drive is connected to the detection unit, and the drive spring unit can vibrate in the first axial direction.
A drive unit connected to the other end of the drive spring unit;
At least one driving conductive portion provided in the driving portion;
At least one detection conductive portion provided in the detection unit;
The drive unit is vibrated in the first axial direction by an electrostatic force that is disposed on the substrate and spaced apart from the drive conductive unit in the third axis direction and is generated between the drive conductive unit and the drive conductive unit. Driving electrodes to be
A detection electrode provided on the substrate so that a capacitance between the detection unit and the detection conductive unit is changed by displacement of the detection unit in the third axis direction. Physical quantity sensor element.   A physical quantity sensor comprising: the physical quantity sensor element according to claim 1; and a package containing the physical quantity sensor element.   An electronic apparatus comprising the physical quantity sensor according to claim 1.

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