JP3212804B2 - Angular velocity sensor and angular velocity detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibrating gyroscope-type angular velocity sensor and an angular velocity sensor for vibrating a minute vibrating piece formed by a semiconductor process or the like and detecting an angular velocity applied to the vibrating piece by deformation generated in the vibrating piece. The present invention relates to a detection device.

[0002]

2. Description of the Related Art FIG.
FIG. 1 is an exploded perspective view showing a conventional vibration gyro-type angular velocity sensor shown in Japanese Unexamined Patent Publication, No. 60-101, in which 60 is a substrate,
61 and 62 are plate-shaped vibrating reeds formed on a part of the substrate 60, and 63 and 64 are formed on a part of the substrate 60 similarly.
A support piece formed so as to connect the base portion of the zero and each of the vibrating pieces 61, 62, electrode plates 65, 66 are bonded to sandwich the substrate 60, and 67a, 67b are formed on the electrode plates 65, 66, respectively. Drive electrodes 68a and 69a are
8b and 69b are detection electrodes formed on the electrode plate 66.

The substrate 60 is a substrate cut out of a silicon single crystal wafer, and the vibrating pieces 61 and 62 and the supporting pieces 63 and 64 are formed by cutting out the substrate 60 by a two-dimensional processing method such as etching. Support pieces 63, 6
Numeral 4 is formed in a thin beam shape and has a predetermined bending rigidity in the X direction and the Y direction.

The driving electrodes 67a and 67b are
2 are disposed so as to cover an equal area from the opposite side end portions of the vibrating bars 61 and 62, and the detection electrodes 68.
a and 68b are opposed to each other with the vibrating piece 61 interposed therebetween so that the electrodes are covered by the vibrating piece 61, and the detection electrodes 69a and 69b are arranged.
“b” is opposed to the vibrating piece 62 so that the electrode is covered by the vibrating piece 62.

FIG. 44 is a connection diagram showing an angular velocity detecting device using the angular velocity sensor. In FIG. 44, reference numeral 71 denotes a constant voltage circuit connected to the vibrating bars 61 and 62, and reference numeral 72 denotes a driving electrode 67a and 67b. Drive circuits 73 and 74 are voltage conversion circuits for converting the capacitance between the detection electrodes 68a and 68b and the vibrating piece 61 into voltages V1 and V2, respectively.
Reference numerals 5 and 76 denote detection electrodes 69b and 69a and the vibrating piece 6, respectively.
This is a voltage conversion circuit that converts the capacitance between the two into voltages V3 and V4, respectively.

Next, the operation will be described. Drive electrode 67
When a voltage is applied between a and 67b and the vibrating reeds 61 and 62, the vibrating reeds 61 and 62 are attracted toward the center of the drive electrode in the Y direction in opposite directions by electrostatic force. Therefore, when an alternating voltage having an angular frequency ω is applied to the drive electrodes 67a and 67b from the drive circuit 72, the vibrating reeds 61 and 62 vibrate in opposite directions in the Y direction.

The resonance frequency ω ₀ of the vibrating bar 61 (62) is determined by the shapes and masses of the vibrating bar 61 (62) and the support bar 63 (64) and the bending rigidity of the support bar 63 (64) in the Y direction. the angular frequency of the alternating voltage is ω _0/2. In this state, when the angular velocity Ω occurs around the Z axis perpendicular to the XY plane, Coriolis force Fc proportional to the angular velocity Ω acts on the vibrating vibrating bars 61 and 62 in the X direction.

In this case, the vibrating bar 61 (6
The displacement in the Y direction during the driving in 2) is Y = a (k1, k2) si
n ω ₀ t. Here, k1 is a constant determined by the spring rigidity, equivalent length, and the like of the support piece 63 (64), and k2 is determined by the drive voltage Vo, the distance D between the drive electrodes, the thickness T of the resonator element, the cross-sectional area S, and the like. Is a constant. Coefficient a that determines the maximum amplitude
Is larger as Vo, T / D and S are larger and D is smaller.

From the above equation, the velocity v of the resonator element in the Y direction is given by
_Y becomes v _Y = aω cos ω ₀ t, and the resonator element 61 (6
Assuming that the equivalent mass of the combination of 2) and the support pieces 63 (64) is m, the Coriolis force Fc is Fc = 2 mΩ × v _Y = 2 ma
ω cos3 ω ₀ t · Ω, the vibrating piece 61 (62) vibrates in the X direction due to the Coriolis force Fc, and its amplitude is the angular velocity Ω.
Is proportional to

The vibrating reed 61 (6
2) and detection electrodes 68a (69a), 68b (69
b) Since the distance between them changes, the change in capacitance due to the change in the distance is converted into the voltage conversion circuits 73, 74, 75, and 76.
Is measured at the voltages V1, V2, V3, and V4 of FIG.

Here, since the vibrations of the vibrating bars 61 and 62 in the Y-axis direction are opposite to each other, the vibrations in the X-axis direction due to the Coriolis force Fc are also opposite to each other as shown in FIG.
In the illustrated state, that is, when the vibrating reed 61 is close to the detecting electrode 68b, the vibrating reed 62 is close to the detecting electrode 69a on the opposite side, the voltages V2 and V4 increase, and the voltages V1 and V3 decrease.

Accordingly, the voltage Δ obtained by subtracting the voltage difference between the two sides
V is ΔV = (V2−V1) − (V3−V4),
This ΔV is a value proportional to the angular velocity Ω. Since this ΔV is proportional to the Coriolis force Fc and is proportional to the coefficient a as shown in the above equation of Fc, it increases as Vo, T / D, and S increase and D decreases as described above.

[0013]

Since the conventional angular velocity sensor is configured as described above, it is difficult to control the driving voltage with respect to Y.
Since the electrostatic force in the direction is small, the drive voltage / angular velocity detection sensitivity ratio is large, and there has been a problem that the drive voltage must be set high to obtain sufficient detection sensitivity.

In order to increase the detection sensitivity, it is conceivable to increase the thickness of the vibrating piece 61 (62) or increase its cross-sectional area. However, the vibrating piece 61 (62) is formed of a thin film or the like. There was a problem that it was impossible to do.

Further, the vibrating bar 61 is driven by the Coriolis force Fc.
By vibrating (62) in the X direction, the drive electrode 67
Since the distance between the a and 67b and the vibrating bar 61 (62) changes, a difference ΔF in electrostatic force between the vibrating bar 61 (62) and the drive electrodes 67a and 67b is applied to the vibrating bar 61 (62), and the Coriolis in the X direction. When the electrostatic force difference ΔF is superimposed on the force Fc, there is a problem that an angular velocity detection error increases.

Further, there is a problem that the structure is complicated because the vibrating piece 61 (62) is sandwiched between the electrodes.

The first aspect of the present invention has been made in order to solve the above-mentioned problems, and has a simple structure in which the detection sensitivity can be increased even at a low driving voltage and an angular velocity detection error due to driving does not occur. The aim is to obtain a sensor.

According to a second aspect of the present invention, there is provided an angular velocity sensor capable of suppressing the vibration of the cantilever base, separating the vibration mode from the cantilever tip, and increasing the degree of freedom in dimensional design of the cantilever. The purpose is to:

A third object of the present invention is to provide an angular velocity sensor capable of increasing the displacement of the detection electrode in the X-axis direction to further improve the angular velocity detection sensitivity.

A fourth object of the present invention is to provide an angular velocity sensor capable of reducing the number of electrodes, facilitating wiring, simplifying masking when forming electrodes, and reducing stray capacitance between leads. I do.

A fifth object of the present invention is to provide an angular velocity sensor capable of detecting displacement with a detection electrode with high sensitivity by elastically supporting a cantilever beam on a support piece.

It is another object of the present invention to provide an angular velocity sensor capable of increasing mechanical strength against impact.

According to the seventh aspect of the present invention, the number of leads from the detection electrode portion passing through the support piece can be reduced, the wiring can be simplified, the masking at the time of forming the electrodes can be simplified, and the floating between the leads can be achieved. It is an object of the present invention to obtain an angular velocity sensor capable of reducing the capacity.

It is another object of the present invention to provide an angular velocity sensor capable of simultaneously detecting angular velocities of two axes around a horizontal axis.

According to the ninth aspect of the present invention, the angular velocity of the two axes around the horizontal axis can be simultaneously detected, and the S / S
An object is to obtain an angular velocity sensor capable of improving the N ratio.

According to a tenth aspect of the present invention, there is provided an angular velocity sensor capable of reducing the number of leads, simplifying wiring and masking, and reducing stray capacitance between the leads by sharing a detection electrode and a drive electrode. The purpose is to gain.

An object of the present invention is to provide an angular velocity sensor capable of appropriately adjusting a resonance frequency determined by the shape of a resonator element.

According to a twelfth aspect of the present invention, a small angular velocity sensor can be used to obtain a high detection sensitivity even at a low driving voltage, and the angular velocity can be calculated and output with higher accuracy without causing an angular velocity detection error due to driving. An object is to obtain an angular velocity detecting device having a simple structure.

According to the thirteenth aspect of the present invention, the vibration of the base of the cantilever can be suppressed, the vibration mode can be separated from the tip of the cantilever, the degree of freedom of the dimensional design of the cantilever can be increased, and the angular velocity calculation can be performed. It is an object of the present invention to obtain an angular velocity detecting device capable of performing the method with high accuracy.

The invention of claim 14 reduces the number of electrodes,
It is an object of the present invention to provide an angular velocity detecting device capable of performing angular velocity detection with high accuracy by calculation while facilitating wiring, simplifying masking when forming electrodes, and reducing stray capacitance between leads.

It is another object of the present invention to provide an angular velocity detecting apparatus capable of performing a desired angular velocity calculation with high accuracy while simultaneously detecting angular velocities of two axes around a horizontal axis.

A sixteenth aspect of the present invention is an angular velocity detecting device capable of simultaneously detecting angular velocities of two axes around a horizontal axis, increasing an electrode area to improve an S / N ratio, and performing angular velocity calculations with high accuracy. The purpose is to gain.

It is another object of the present invention to provide an angular velocity sensor that can increase the detection sensitivity even with a low driving voltage and can suppress the occurrence of an angular velocity detection error due to driving.

An object of the present invention is to provide an angular velocity sensor capable of detecting a change in capacitance between detection electrodes with high sensitivity.

An object of the nineteenth aspect is to provide an angular velocity sensor capable of increasing the mechanical support strength of the resonator element.

According to a twentieth aspect of the present invention, there is provided an angular velocity sensor capable of suppressing vibration of the base of the cantilever in the X-axis direction, separating vibration modes, and increasing the degree of freedom in dimensional design of the cantilever. The purpose is to:

An object of the present invention is to provide an angular velocity sensor capable of simultaneously detecting angular velocities of two axes around a horizontal axis using a rectangular vibrating reed and four pairs of detection electrodes.

According to the twenty-second aspect of the present invention, the angular velocities of the two axes around the horizontal axis can be simultaneously detected, and the electrode area can be increased.
It is an object of the present invention to obtain an angular velocity sensor capable of improving the S / N ratio.

An object of a twenty-third aspect of the present invention is to provide an angular velocity sensor capable of appropriately adjusting a resonance frequency determined by the shape of a resonator element.

It is another object of the present invention to provide an angular velocity sensor capable of simplifying a mask pattern of the detection electrode and reducing the number of lead wires by sharing the detection electrode.

According to a twenty-fifth aspect of the present invention, by reducing the driving power with respect to the driving amplitude, it is possible to increase the angular velocity detection sensitivity even when the vibrating piece is thin or small, and to obtain an angular velocity detecting device capable of accurately detecting the angular velocity. The purpose is to:

According to a twenty-sixth aspect of the present invention, by reducing the driving power with respect to the driving amplitude, the angular velocity detection sensitivity can be increased even if the vibrating piece is made thinner or smaller, and the angular velocity can be accurately detected, and the two axes can be accurately detected. It is an object of the present invention to provide an angular velocity detecting device capable of performing the angular velocity detection simultaneously and accurately without causing a detection error.

It is another object of the present invention to provide an angular velocity detecting device capable of detecting an angular velocity having a high S / N ratio without causing a detection error.

It is another object of the present invention to provide an angular velocity sensor capable of realizing accurate angular velocity detection by increasing the ratio of angular velocity detection sensitivity / drive voltage using an elongated diaphragm.

An object of the present invention is to provide an angular velocity sensor which can simplify the angular velocity detection processing, reduce the number of electrodes, and realize a simplified mask pattern.

An object of the present invention is to provide an angular velocity sensor capable of reducing the number of electrodes of the piezoelectric element and simplifying the connection circuit by sharing the electrodes of the piezoelectric element.

According to a thirty-first aspect of the present invention, there is provided an angular velocity sensor capable of increasing the electromechanical conversion efficiency per area of the piezoelectric element and improving the detection sensitivity without forming a neutral region in the piezoelectric film of the piezoelectric element. The purpose is to gain.

It is another object of the present invention to provide an angular velocity sensor capable of detecting a change in capacitance between detection electrodes with high sensitivity.

A third object of the present invention is to provide an angular velocity sensor capable of increasing the mechanical support strength of the resonator element.

According to a thirty-fourth aspect of the present invention, the vibration mode can be separated by suppressing the base portion of the vibrating reed from vibrating in the axial direction, whereby the degree of freedom in dimensional design as a cantilever can be increased. An object is to obtain an angular velocity sensor.

It is another object of the present invention to provide an angular velocity sensor capable of significantly improving the detection sensitivity by reducing the horizontal rigidity of a vibrating reed as a cantilever.

According to a thirty-sixth aspect of the present invention, the vertical vibration of the vibrating reed caused by the vibration of the piezoelectric element is obtained by a change in the sum of capacitance due to the vertical displacement of each pair of detection electrodes, and the vibration is calculated from the frequency component of the change in capacitance. It is an object of the present invention to obtain an angular velocity detecting device capable of determining an angular velocity about a central axis in a width direction of a piece.

A further object of the present invention is to provide an angular velocity detecting device capable of obtaining an angular velocity about the central axis in the width direction of the resonator element even when the facing area of the detection electrodes is invariable.

According to a thirty-eighth aspect of the present invention, there is provided an angular velocity detecting device capable of maintaining a vibration velocity of a horizontal bending vibration of a vibrating piece at a predetermined value based on a ratio of a capacitance sum and a capacitance difference between a pair of detection electrodes. With the goal.

A thirty-ninth aspect of the present invention is an angular velocity detecting device capable of maintaining a horizontal vibration velocity of a vibrating reed at a predetermined value by using a braking admittance of a piezoelectric element and a voltage and a current applied to the piezoelectric element. The purpose is to gain.

[0056]

An angular velocity sensor according to a first aspect of the present invention is provided on a vibrating piece and a substrate facing the vibrating piece, and has an invariable overlapping area with respect to horizontal vibration of the vibrating piece. A pair of drive electrodes and at least two pairs of detection electrodes whose areas overlapping each other with respect to the horizontal vibration of the vibrating piece change mutually are provided.

According to a second aspect of the present invention, there is provided an angular velocity sensor having a holding portion fixed to a substrate, other than the holding portion, being disposed so as to face the substrate and bend horizontally with respect to the substrate surface. A cantilever having a deformable supporting piece in the middle and bending and deforming in a direction perpendicular to the substrate surface on the holding section side from the supporting piece, and the cantilever on the holding section side and the A pair of drive electrodes provided on the substrate, and a pair of drive electrodes provided on the cantilever on the tip end side of the support piece and on the substrate at a position facing the cantilever, respectively;
At least two pairs of detection electrodes whose overlapping areas change with respect to the horizontal vibration on the tip end side are provided.

In the angular velocity sensor according to a third aspect of the present invention, the detection electrode is arranged on the tip side of the vibrating reed or the cantilever with respect to the drive electrode.

According to a fourth aspect of the present invention, there is provided an angular velocity sensor, comprising: a pair of drive detection electrodes having a mutually overlapping area that varies between a vibrating reed and a substrate facing the vibrating reed due to horizontal vibration of the vibrating reed; Is provided.

An angular velocity sensor according to a fifth aspect of the present invention is such that the vibrating reed is a cantilever, and the support piece is provided at one end or halfway of the cantilever in the axial direction of the cantilever.

In the angular velocity sensor according to a sixth aspect of the present invention, the vibrating piece is a doubly supported beam, the supporting piece is provided at both ends of the doubly supported beam in the axial direction thereof, and the drive electrode and the detection electrode or the drive detection electrode are provided. It is arranged symmetrically with respect to a center vertical plane in the width direction of the doubly supported beam.

In the angular velocity sensor according to the seventh aspect of the present invention, one of a plurality of detection electrodes formed on the vibrating reed or the doubly supported beam and a plurality of detection electrodes formed on the substrate side corresponding to these are commonly used. This is a detection electrode.

An angular velocity sensor according to an eighth aspect of the present invention has a holding portion fixed to a substrate, and other than the holding portion, the sensor is disposed so as to face the substrate, and is bent perpendicularly to the surface of the substrate. A rectangular vibrating piece to be deformed, a supporting piece provided at each corner of the rectangular vibrating piece and bending and deforming in a horizontal direction with respect to the substrate surface, and a rectangular vibrating piece and the substrate opposed thereto, respectively. The driving capacitance portion, which is provided and has an invariable overlapping area with respect to the horizontal vibration of the rectangular vibrating piece, and an mutually overlapping area with respect to the horizontal vibration of the rectangular vibrating piece. And four pairs of detection electrodes in two horizontal axis directions changing to

In the angular velocity sensor according to the ninth aspect of the present invention, there are provided four driving units which are mutually symmetrical with respect to the central axis of the rectangular vibrating bar, wherein the area of the rectangular vibrating bar that overlaps with the horizontal vibration changes. It is provided with a detection electrode.

An angular velocity sensor according to a tenth aspect of the present invention
At least one of the drive electrode and the detection electrode formed on the vibrating reed or the doubly supported beam and the drive electrode and the detection electrode formed on the substrate side corresponding to these are used as common electrodes.

An angular velocity sensor according to the invention of claim 11 is
A weight for adjusting the resonance frequency is provided on a part of the upper surface of the resonator element.

An angular velocity detecting device according to a twelfth aspect of the present invention is provided on a vibrating reed and a substrate facing the vibrating reed, and a pair of drive electrodes having an invariable overlapping area with respect to horizontal vibration of the vibrating reed. And, provided that at least two pairs of detection electrodes mutually overlapping areas for the horizontal vibration of the vibrating reed are mutually changed, when the vibrating reed is vibrated in the vertical direction near the resonance frequency, The angular velocity detecting circuit detects the angular velocity of the vibrating reed around the axis from the frequency component of the capacitance difference between the detection electrodes.

According to a thirteenth aspect of the present invention, there is provided an angular velocity detecting device having a holding portion fixed to a substrate, other than the holding portion, disposed close to and opposed to the substrate, and in a horizontal direction with respect to the substrate surface. A cantilever that has a supporting piece that bends and deforms in the middle and that bends and deforms mainly in the direction perpendicular to the substrate surface on the holding section side from the supporting piece, and the cantilever on the holding section side and faces the cantilever. And a pair of drive electrodes respectively provided on the substrate at the position, the cantilever beam at the tip end side of the support piece and the substrate at the position facing the cantilever beam, and the horizontal direction at the tip end side. Providing at least two pairs of detection electrodes whose mutually overlapping areas are mutually changed with respect to vibration, and when the cantilever is vibrated in the vertical direction near the resonance frequency, the capacitance difference between the detection electrodes is reduced. From the above frequency components, The speed detecting circuit is obtained so as to detect the axis angular velocity around the cantilever.

According to a fourteenth aspect of the present invention, there is provided an angular velocity detecting apparatus, wherein two pairs of drive detections are provided between the vibrating reed and the substrate facing the vibrating reed, in which the area of the vibrating reed overlapping with the horizontal vibration changes. An electrode is provided, and when the two pairs of drive detection electrodes are driven in phase to vibrate the vibrating reed vertically in the vicinity of a resonance frequency, from the frequency component of the capacitance difference between the two pairs of drive detection electrodes, The angular velocity detecting circuit detects the angular velocity of the resonator element around the axis.

An angular velocity detecting device according to a fifteenth aspect of the present invention has a holding portion fixed to the substrate, and other than the holding portion, the positioning device is disposed close to and opposed to the substrate, and is bent in a direction perpendicular to the surface of the substrate. A deformable rectangular vibrating piece, a support piece provided at each corner of the rectangular vibrating piece and bending and deforming in the horizontal direction with respect to the substrate surface, and the rectangular vibrating piece and the substrate opposed thereto, respectively. The drive electrode provided is such that the area where the rectangular vibrating reed overlaps with the horizontal vibration is invariable, and the area where the rectangular vibrating reed overlaps with the horizontal vibration changes mutually. Two pairs of detection electrodes in the horizontal axis direction are provided, and the angular velocity detection circuit detects an angular velocity of each of the rectangular vibrating reeds around each horizontal axis from the frequency component of the capacitance difference between the pair of detection electrodes. Is like

In the angular velocity detecting device according to the sixteenth aspect of the present invention, there is provided an angular velocity detecting device comprising four pairs of rectangular vibrating bars whose points of overlap with each other change with respect to the horizontal vibration of the rectangular vibrating bars. And the sum of the capacitances of the two pairs of drive detection electrodes in the horizontal axis direction when each of the drive detection electrodes is driven in-phase to oscillate the rectangular vibrating piece in the vertical direction near the resonance frequency. The angular velocity detecting circuit detects the angular velocity of each of the rectangular vibrating reeds about each horizontal axis from the above-mentioned frequency component of the capacitance difference of each set.

An angular velocity sensor according to a seventeenth aspect of the present invention
A piezoelectric element provided on one surface of the vibrating reed and polarized so as to expand and contract the vibrating reed in a horizontal direction, and an area overlapping the lower surface of the vibrating reed and the substrate with respect to the horizontal vibration of the vibrating reed; Are provided with at least two pairs of detection electrodes.

The angular velocity sensor according to claim 18 is:
The supporting piece is provided on the cantilever support side of the vibrating piece, and the detection electrode is provided on the free end side of the vibrating piece.

The angular velocity sensor according to the nineteenth aspect of the present invention
The supporting piece is provided on the both-side supporting side of the vibrating piece, and the detection electrodes are provided symmetrically with respect to the center vertical plane in the width direction of the vibrating piece.

An angular velocity sensor according to a twentieth aspect of the present invention
A supporting piece is provided in the middle of the vibrating piece, a piezoelectric element is provided on the vibrating piece on the holding portion side of the supporting piece, and a detection electrode is provided on the tip end side of the supporting piece and a center vertical surface in the width direction of the vibrating piece. Are arranged symmetrically with respect to.

An angular velocity sensor according to a twenty-first aspect of the present invention
A rectangular vibrating reed having a holding portion fixed to the substrate, being disposed in close proximity to one surface of the substrate except for the holding portion, and being bent and deformed mainly in a direction perpendicular to the substrate surface; A supporting piece provided on each corner of the vibrating piece and deforming in the horizontal direction with respect to the substrate surface; and a piezoelectric element provided on one side of the rectangular vibrating piece and polarized so as to expand and contract in the circumferential direction from the center thereof. And four pairs of detection electrodes in two horizontal axis directions in which an area overlapping each other in the horizontal direction with respect to each horizontal vibration of the rectangular vibration piece changes on the rectangular vibrating piece and the substrate. Is provided.

An angular velocity sensor according to a twenty-second aspect of the present invention
The rectangular vibrating reed is provided with four pairs of detection electrodes whose areas overlapping each other change with respect to the vibration in the horizontal axis direction and which are point-symmetric with respect to the center axis of the rectangular vibrating reed.

An angular velocity sensor according to a twenty-third aspect of the present invention
A weight for adjusting the resonance frequency is provided in a part of the resonator element.

An angular velocity sensor according to a twenty-fourth aspect of the present invention
A plurality of detection electrodes formed on a cantilever, a cantilever, or a rectangular vibrating piece are used as a common electrode.

An angular velocity detecting device according to a twenty-fifth aspect of the present invention provides a piezoelectric element provided on one surface of a vibrating reed and polarized so as to expand and contract the vibrating reed in a predetermined direction; When at least two pairs of detection electrodes whose overlapping areas change with respect to the horizontal vibration of the vibrating reed are provided, and the piezoelectric element is driven to vibrate the vibrating reed vertically near the resonance frequency. The angular velocity detecting circuit detects the angular velocity of the vibrating reed around the axis from the frequency component of the capacitance difference between the detection electrodes.

An angular velocity detecting device according to a twenty-sixth aspect of the present invention has a holding portion fixed to a substrate, and other than the holding portion, the holding device is disposed so as to face one surface of the substrate and is close to the surface of the substrate. A rectangular vibrating piece deformed in the vertical direction, a supporting piece provided at each corner of the rectangular vibrating piece, deforming in the horizontal direction with respect to the substrate surface, and a rectangular vibrating piece provided on one surface of the rectangular vibrating piece. A piezoelectric element polarized so as to expand and contract in the circumferential direction from the center thereof is provided, and when the piezoelectric element is driven to vibrate the vibrating reed vertically in the vicinity of the resonance frequency, the distance between each pair of detection electrodes is increased. The angular velocity detecting circuit detects the angular velocity of each of the rectangular vibrating bars around each horizontal axis from the frequency component of the capacitance difference.

In the angular velocity detecting device according to the twenty-seventh aspect, the area of the rectangular vibrating reed which overlaps with respect to the horizontal vibration of the vibrating reed changes, and the rectangular vibrating reed is point-symmetric with respect to the central axis of the vibrating reed. A pair of detection electrodes is provided, and when the piezoelectric element is driven to oscillate the rectangular vibrating piece vertically in the vicinity of the resonance frequency, a set of capacitance sums between the two pairs of detection electrodes in each horizontal axis direction is set. The angular velocity detecting circuit detects the angular velocity of each of the rectangular vibrating reeds around each horizontal axis from the frequency component of the capacitance difference of each set.

An angular velocity sensor according to a twenty-eighth aspect of the present invention
The vibrating reed is horizontally symmetrically provided on one surface of the elongated vibrating reed so as to sandwich the piezoelectric film between two pairs of upper and lower electrodes so that the vibrating reed is expanded and contracted in the horizontal direction. And two pairs of detection electrodes whose overlapping areas change with respect to the horizontal vibration of the vibrating reed are provided on the vibrating reed and the substrate, respectively.

The angular velocity sensor according to claim 29 is
A pair of detection electrodes are formed on the vibrating reed and the substrate, each having a constant facing area with respect to the horizontal vibration of the vibrating reed.

The angular velocity sensor according to claim 30 is
At least one electrode of one side of the piezoelectric element is shared among the two pairs of electrodes of the piezoelectric element.

The angular velocity sensor according to claim 31 is
The piezoelectric elements are stacked so that each piezoelectric film is sandwiched between each pair of electrodes, and are arranged symmetrically with respect to the center vertical plane in the width direction of the resonator element.

The angular velocity sensor according to claim 32 is:
The vibrating reed is a cantilever, a supporting piece is provided on the cantilever support side of the vibrating piece, and a detection electrode is provided on a free end side of the vibrating piece.

The angular velocity sensor according to claim 33 is
The vibrating reed is a doubly supported beam, the support piece is provided on the doubly supported side of the vibrating reed, and the detection electrodes are provided symmetrically with respect to the center vertical plane in the width direction of the vibrating reed.

The angular velocity sensor according to claim 34 is:
The vibrating piece is a cantilever, and the supporting piece is provided in the middle of the vibrating piece, and the supporting piece has bending elasticity in a vertical direction,
The vertical displacement is smaller on the holding part side than on the tip part side , the piezoelectric element is provided on the holding part side, and the detection electrode is provided on the tip part side.

The angular velocity sensor according to claim 35 is
A penetrating portion is provided in a part of the vibrating reed along a center vertical plane in the width direction of the vibrating reed.

The angular velocity detecting device according to claim 36 is provided with two pairs of detecting electrodes whose overlapping areas change with respect to horizontal vibration of the vibrating reed, and drives the piezoelectric element to the angular velocity detecting circuit. When the vibrating reed is flexibly vibrated in the vicinity of the resonance frequency in the horizontal direction, an angular velocity about the axis of the vibrating reed is detected from the frequency component of the sum of capacitance between the detection electrodes of each pair. .

An angular velocity detecting device according to a thirty-seventh aspect of the present invention is the angular velocity detecting device according to the thirteenth aspect, wherein the opposing area is invariable with respect to horizontal vibration of the resonator element.
A pair of detection electrodes are provided, and the angular velocity detection circuit drives the piezoelectric element to bend and vibrate the vibrating piece in the horizontal direction near the resonance frequency. The angular velocity about the axis of one piece is detected.

In the angular velocity detecting device according to the thirty-eighth aspect of the present invention, the angular velocity detecting circuit controls the driving voltage or the driving current so that the ratio of the capacitance difference to the capacitance sum between the detection electrodes of each pair becomes constant. The piezoelectric element is driven at a predetermined vibration speed.

According to a thirty-ninth aspect of the present invention, there is provided an angular velocity detecting device, wherein an electric current applied to a piezoelectric element is supplied to an angular velocity detecting circuit.
The voltage or current is controlled so that the piezoelectric element is driven at a predetermined vibration speed so that the difference between the voltage applied to the piezoelectric element and the product of the braking admittance of the piezoelectric element becomes a predetermined value. Things.

[0095]

The angular velocity sensor according to the first aspect of the present invention drives a driving electrode to vibrate the vibrating reed in the direction perpendicular to the substrate surface in the vicinity of the resonance frequency of the vibrating reed. A horizontal axis vibration perpendicular to the axis of the vibrating reed generated by the Coriolis force based on the vertical vibration and depending on the elasticity of the supporting piece can be taken out as a capacitance difference between the detection electrodes.

The angular velocity sensor according to the second aspect of the present invention
Prevent the base of the cantilever from vibrating in the X-axis direction,
The vibration mode can be separated by allowing the tip of the cantilever to vibrate by the Coriolis force in the X-axis direction due to the X-direction bending elasticity of the support piece.

The angular velocity sensor according to the third aspect of the present invention
By increasing the distance from the support piece that flexurally vibrates in the X-axis direction of the cantilever to the detection electrode, displacement of the detection electrode in the X-axis direction during vibration is increased, and the difference in capacitance between the detection electrodes is increased.

The angular velocity sensor according to the fourth aspect of the present invention
The two pairs of drive detection electrodes are driven in phase to vibrate the vibrating reed in the direction perpendicular to the substrate surface in the vicinity of the resonance frequency, and the angular velocity applied around the axis of the resonating reed and the Coriolis force based on the vertical vibration described above cause the vibrating reed to vibrate. Horizontal vibration perpendicular to the axis of the vibrating reed generated depending on the elasticity of the support piece can be extracted as a capacitance difference between the two pairs of drive detection electrodes.

The angular velocity sensor according to the invention of claim 5 is
The support piece allows displacement of the cantilever, and the displacement can be detected by the detection electrode with high sensitivity.

The angular velocity sensor according to the invention of claim 6 is:
By supporting the doubly supported beam with the two support pieces, it is possible to sufficiently secure the mechanical strength of the doubly supported beam against impact.

The angular velocity sensor according to the invention of claim 7 is
By making the detection electrodes formed on the vibrating piece, cantilever or cantilever beam, and the substrate common, the number of leads passing through the support piece and the like can be reduced, and the wiring can be simplified. Masking during formation is simplified, and stray capacitance between leads can be reduced.

The angular velocity sensor according to the invention of claim 8 is
By driving the drive electrode, the rectangular vibrating piece is vibrated in the direction perpendicular to the substrate surface in the vicinity of the resonance frequency of the rectangular vibrating piece, and based on the angular velocity applied around each horizontal axis of the rectangular vibrating piece and the vertical vibration described above. Vibration in the horizontal axis direction perpendicular to each horizontal axis of the rectangular vibrating piece, which is generated depending on the elasticity of the supporting piece of the rectangular vibrating piece due to Coriolis force, can be taken out as a capacitance difference between each pair of detection electrodes. .

The ninth aspect of the present invention provides an angular velocity sensor comprising:
The four pairs of drive detection electrodes which are point-symmetric with respect to the center axis of the rectangular vibrating piece are driven in phase, and the rectangular vibrating piece vibrates in the direction perpendicular to the substrate surface in the vicinity of the resonance frequency of the rectangular vibrating piece. Each of the rectangular vibrating reeds is perpendicular to each horizontal axis of the rectangular vibrating reed generated depending on the elasticity of the supporting piece of the rectangular vibrating reed by the angular velocity applied around each horizontal axis direction of the rectangular vibrating reed and the Coriolis force based on the vertical vibration. A horizontal vibration in the horizontal axis direction can be taken out as a capacitance difference between each pair of a pair of drive detection electrodes in the horizontal axis direction.

The angular velocity sensor according to the tenth aspect of the present invention reduces the number of electrodes and simplifies wiring by using a common electrode for the driving electrode and the detection electrode formed on the vibrating piece, the cantilever or the substrate. In addition, it is possible to simplify masking when forming electrodes and to reduce stray capacitance between leads.

In the angular velocity sensor according to the eleventh aspect, the resonance frequency of each of the vibrating bars can be adjusted by the weight provided on the vibrating bar or the rectangular vibrating bar.

The angular velocity detecting device according to the twelfth aspect of the present invention is such that the driving electrode is driven to vibrate the vibrating reed in the direction perpendicular to the substrate surface near the resonance frequency of the vibrating reed, and the angular velocity applied around the axis of the vibrating reed is determined. Using the angular velocity detection circuit, the vibration in the horizontal axis direction perpendicular to the axis of the vibrating reed generated by the Coriolis force based on the vertical vibration and the frequency of the capacitance difference between the detection electrodes is obtained. The angular velocity around the axis of the resonator element is detected by detecting the component.

According to the thirteenth aspect of the present invention, the angular velocity detecting device prevents the base portion of the cantilever from vibrating in the X-axis direction, while the tip portion of the cantilever is moved in the X-axis direction by the X-direction bending elasticity of the supporting piece. By vibrating with Coriolis force, vibration modes can be separated, and the angular velocity can be detected with high accuracy by arithmetic processing.

According to a fourteenth aspect of the present invention, in the angular velocity detecting device, two pairs of drive detecting electrodes are driven in the same phase to vibrate the vibrating reed in the direction perpendicular to the substrate surface in the vicinity of the resonance frequency, and the vibration is applied around the axis of the vibrating reed. The horizontal vibration perpendicular to the axis of the vibrating piece, which is generated depending on the elasticity of the supporting piece of the vibrating piece by the Coriolis force based on the angular velocity and the vertical vibration, is applied to the two pairs of drive detection electrodes by using an angular velocity detecting circuit. The angular velocity around the axis of the resonator element is detected by detecting the capacitance difference between the above-mentioned frequency components.

In the angular velocity detecting device according to the fifteenth aspect of the present invention, the driving electrode is driven to vibrate the rectangular vibrating piece in the direction perpendicular to the substrate surface in the vicinity of the resonance frequency of the rectangular vibrating piece. Vibration in the horizontal axis direction perpendicular to each horizontal axis of the rectangular vibrating piece, which is generated depending on the elasticity of the supporting piece of the rectangular vibrating piece by the Coriolis force based on the angular velocity applied around the horizontal axis and the vertical vibration, An angular velocity detecting circuit detects an angular velocity of each of the rectangular vibrating reeds around each horizontal axis by detecting the capacitance difference between the pair of detection electrodes based on the frequency component.

In the angular velocity detecting device according to the sixteenth aspect of the present invention, the four pairs of drive detection electrodes which are point-symmetric with respect to the center axis of the rectangular vibrating piece are driven in phase, and the rectangular vibrating piece is moved relative to the substrate surface. The rectangular vibrating piece is vibrated in the vertical direction in the vicinity of the resonance frequency of the rectangular vibrating piece, and the angular velocity generated around each horizontal axis of the rectangular vibrating piece and the Coriolis force based on the vertical vibration described above depend on the elasticity of the supporting piece. The vibration in the horizontal axis direction perpendicular to each horizontal axis of the vibrating reed is generated by the angular velocity detection circuit, and the above frequency of the capacitance difference of each set is set as a set of the sum of the capacitances between two pairs of drive detection electrodes in each horizontal axis direction. The angular velocity of each of the rectangular vibrating pieces around each horizontal axis is detected by detecting the component.

An angular velocity sensor according to a seventeenth aspect of the present invention drives the piezoelectric element and causes the vibrating reed to extend perpendicularly to the substrate surface by the expansion and contraction vibration of the piezoelectric element in a predetermined direction. The vibrating piece vibrates in the vicinity, and due to the angular velocity applied around the axis of the vibrating piece and the Coriolis force based on the vertical vibration, a horizontal axial vibration perpendicular to the vibrating piece axis generated depending on the elasticity of the supporting piece is generated by the vibrating piece. Is obtained as the capacitance difference between the detection electrodes caused by the horizontal displacement of.

In the angular velocity sensor according to the eighteenth aspect of the present invention, the support piece promotes the displacement of the cantilever, and enables a high-sensitivity detection of a change in capacitance between the detection electrodes.

The angular velocity sensor according to the nineteenth aspect of the present invention supports the vibrating reed by two supporting pieces, and thus functions to enhance mechanical support strength while assisting the displacement of the vibrating piece.

In the angular velocity sensor according to the twentieth aspect, the vibration mode of the tip portion of the cantilever can be separated from the base portion of the cantilever beam where the vibration is suppressed, so that accurate detection of the vibration displacement by the change in capacitance can be performed. In addition, the degree of freedom in designing the dimensions of the cantilever is improved.

According to the twenty-first aspect of the present invention, the angular velocity sensor drives the piezoelectric element and expands and contracts the rectangular vibrating piece in a direction perpendicular to the substrate surface by expanding and contracting the piezoelectric element from the center of the rectangular vibrating piece to the peripheral direction. Vibrating near the resonance frequency of the rectangular vibrating piece, and each of the rectangular vibrating pieces generated depending on the elasticity of the supporting piece by the Coriolis force based on the angular velocity and vertical vibration of the rectangular vibrating piece around two horizontal axes. Vibration in the horizontal axis direction perpendicular to the horizontal axis is obtained as a capacitance difference between each pair of detection electrodes caused by horizontal displacement of the rectangular vibrating piece.

In the angular velocity sensor according to the twenty-second aspect, the rectangular vibrating reed has a horizontal axial direction perpendicular to each of two horizontal axes, and the sum of capacitances between two pairs of detecting electrodes in each horizontal axial direction is obtained. The capacitance difference in the uniaxial direction is removed, and then the difference is obtained as the capacitance difference of the above-mentioned capacitance sum.

In the angular velocity sensor according to the twenty-third aspect, the resonance frequency of the vibrating reed is adjusted by a weight provided on one side of the vibrating reed.

The angular velocity sensor according to the twenty-fourth aspect of the present invention uses a common detection electrode, thereby reducing the number of leads passing through the support pieces and the like, simplifying the wiring work, simplifying the wiring, and improving the above detection. Masking during electrode formation is simplified, and stray capacitance between leads is reduced.

The angular velocity detecting device according to the twenty-fifth aspect of the present invention is characterized in that a horizontal axial vibration perpendicular to the axis of the vibrating piece, which is generated depending on the elasticity of the supporting piece, is calculated by an angular velocity detecting circuit to calculate the horizontal displacement of the vibrating piece. And the capacitance difference between the detection electrodes of each pair.

The angular velocity detecting device according to the twenty-sixth aspect of the present invention is characterized in that the angular velocity detecting circuit calculates horizontal axis vibrations perpendicular to each horizontal axis of the rectangular vibrating piece generated depending on the elasticity of the supporting piece by the angular velocity detecting circuit. Is obtained as a capacitance difference between each pair of detection electrodes caused by the horizontal displacement of the vibrating bar, and the angular velocity of each rectangular vibrating bar around each horizontal axis is detected from the frequency component of the capacitance difference.

According to a twenty-seventh aspect of the present invention, in the angular velocity detecting device, a horizontal axis direction vibration perpendicular to each horizontal axis of the rectangular vibrating reed is calculated by an angular velocity detecting circuit between two pairs of detecting electrodes in each horizontal axis direction. The capacitance difference in the one axis direction is removed by calculating the sum of the capacitances, the capacitance difference of the capacitance sum is obtained, and the angular velocity of each of the rectangular vibrating pieces around each horizontal axis is detected from the frequency component of the capacitance difference. .

In the angular velocity sensor according to the twenty-eighth aspect of the present invention, the elongated vibrating piece is bent and vibrated at a resonance frequency in a horizontal direction with respect to the substrate surface by driving the piezoelectric element, and the Coriolis force due to the angular velocity acting around the axis of the vibrating piece. As a result, the vibrating bar vibrates and displaces in a direction perpendicular to the axis, causing a change in capacitance between the detection electrodes due to the vibration displacement, and makes this change available as angular velocity data.

In the angular velocity sensor according to the twenty-ninth aspect, the capacitance between the detection electrodes is changed only with respect to the distance between the electrodes, and the number of outputs of the detection electrodes is reduced. In addition to simplifying the configuration, it is also possible to simplify the mask pattern when forming the electrodes by reducing the number of lead wires.

In the angular velocity sensor according to the thirtieth aspect, the piezoelectric elements may be polarized in the same direction, and voltages in opposite directions may be applied between the two electrodes and the common electrode opposed to the piezoelectric element. The polarization of the piezoelectric body between the two electrodes and the common electrode facing each other is set in the opposite direction, and the same voltage is applied, or the elongated vibrating reed is caused to vibrate flexibly in the horizontal direction.

The angular velocity sensor according to the thirty-first aspect of the present invention applies a voltage in the opposite direction to a pair of piezoelectric elements polarized in the same direction, or applies the same voltage to a pair of piezoelectric elements polarized in the opposite direction. By applying a voltage, the elongated vibrating reed is caused to flexurally vibrate in the horizontal direction.

The angular velocity sensor according to the thirty-second aspect of the present invention is such that the vibrating reed, which is a cantilever, is horizontally bent and vibrated on the substrate surface by a piezoelectric element provided thereon, and when an angular velocity around the axis of the vibrating reed is applied. The vertical vibration of the vibrating reed which depends on the vertical elasticity of the support piece provided on the fixed end side of the vibrating reed is detected by the capacitance between the detection electrodes provided on the free end side of the vibrating reed. Detect angular velocity.

The angular velocity sensor according to the thirty-third aspect of the present invention is such that when the doubly supported beam is horizontally bent and vibrated on the substrate surface by the piezoelectric element provided thereon, when the angular velocity about the axis of the doubly supported beam is applied. The vertical vibration of the doubly supported beam generated depending on the vertical elasticity of the support piece provided on the fixed end side of the beam is caused by the electrostatic force between the detection electrodes provided symmetrically about the center line perpendicular to the axis of the doubly supported beam. The angular velocity is detected by detecting the capacitance.

In the angular velocity sensor according to the thirty-fourth aspect, the base of the cantilever is horizontally bent and vibrated on the substrate surface by the piezoelectric element provided thereon, and when the angular velocity around the axis of the cantilever is applied, The vertical vibration of the tip of the cantilever generated depending on the vertical elasticity of the support piece provided in the middle of the cantilever is caused by the capacitance between the detection electrodes provided at the tip of the cantilever. Detect and detect angular velocity.

In the angular velocity sensor according to the thirty-fifth aspect of the present invention, the effective rigidity of the vibrating piece in the horizontal direction is reduced by the penetrating portion provided along the extension axis of the elongated vibrating piece.

In the angular velocity detecting device according to the thirty-sixth aspect, the piezoelectric element is driven by the drive control circuit of the angular velocity detecting circuit, and the piezoelectric element vibrates in the axial direction of the vibrating reed in directions opposite to each other in the axial direction. By vibrating the elongated vibrating reed horizontally on the substrate surface in the vicinity of the resonance frequency of the vibrating reed, the vibrating reed is supported by the angular velocity applied around the axis of the vibrating reed and the Coriolis force based on the horizontal vibration. The vertical vibration of the vibrating reed, which depends on the resilience of the vibrating reed, is determined by the change in the sum of capacitance between a pair of detection electrodes caused by the vertical displacement of the vibrating reed, and the frequency component of the change in sum of capacitance is detected. The angular velocity around the axis of the resonator element is detected.

The angular velocity detecting device according to claim 37, wherein the piezoelectric element is driven by a drive control circuit of the angular velocity detecting circuit to cause the elongated vibrating piece to bend and vibrate near the resonance frequency of the vibrating piece horizontally on the substrate surface, The vertical vibration of the vibrating reed generated when an angular velocity is applied around the axis of the vibrating reed is determined by the capacitance change between a pair of detection electrodes whose facing area is invariable with respect to the horizontal vibration of the vibrating reed. By detecting the component, the angular velocity around the axis of the resonator element is detected.

The angular velocity detecting device according to the thirty-eighth aspect detects the vertical vibration of the vibrating reed based on the ratio of the capacitance difference to the capacitance sum between the pair of detection electrodes, and makes the piezoelectric element have a constant ratio. The piezoelectric element is driven by controlling the driving voltage or the driving current of the vibrating piece to maintain the vibration speed of the horizontal bending vibration of the vibrating piece at a predetermined value.

An angular velocity detector according to a thirty-ninth aspect of the present invention detects a voltage V and a current I applied to a piezoelectric element, and sets I-Yd ×
The piezoelectric element is driven by controlling the drive voltage or drive current of the piezoelectric element so that V becomes a predetermined value, and the vibration speed of the horizontal bending vibration of the elongated vibration piece is maintained at the predetermined value.

[0134]

【Example】

Embodiment 1 FIG. An embodiment of the present invention will be described below with reference to the drawings. 1, 2 and 3, reference numeral 1 denotes a silicon substrate (hereinafter, referred to as a Si substrate) as a substrate horizontally disposed in an XZ coordinate plane, and 2 denotes a silicon substrate which is disposed close to and parallel to the Si substrate 1. A plate-like cantilever (vibrating piece) as a vibrating piece that is bent and deformed mainly in a direction perpendicular to the Si substrate 1, that is, in the Y-axis direction, at least one end of the cantilever 2 has an axis thereof at one end thereof. A support piece provided in the G direction, that is, a center direction passing through the center in the width direction of the cantilever 2, and which bends and deforms in the horizontal direction with respect to the Si substrate 1, that is, in the X-axis direction, 3 a through this support piece 3 A holding portion for holding the cantilever 2, the lower surface of which is fixed on the Si substrate 1. 4 is a drive electrode on one side provided on the surface of the cantilever 2 opposite to the Si substrate 1 on the front side;
Reference numeral 5 denotes another drive electrode provided on the Si substrate 1 so as to face the drive electrode 4. In FIG. 1, the direction of vibration is indicated by X
The XZ coordinate system of the axis and the Z axis is shown in FIG.
The axes are shown using Y-X coordinate systems, and the configuration and operation will be described with reference to these coordinate systems in FIG.

6a and 6b are holding portions 3a of the cantilever 2.
The detection electrodes 7a and 7b provided on the opposite surface to the Si substrate 1 on the other side have detection electrodes 6a and 6b on the Si substrate 1, respectively.
b is a detection electrode on the other side provided opposite to b.
A first detection electrode pair is constituted by 7a, and a second detection electrode pair is constituted by 6b and 7b.

Here, the drive electrode 5 is formed so as to have a large width and length so as to cover the entire drive electrode 4, and the capacitance does not change with respect to the vibration of the cantilever 2 in the X-axis direction. , The capacitance Cd between the drive electrodes 4 and 5 as the drive capacitance portion P
Is a constant K where εS determined by the material and shape is a constant K, where D is the distance between the drive electrodes 4 and 5, D is the dielectric constant of the medium between the electrodes 4 and 5, and S is the facing area between the electrodes. , C
d = εS / D = K / D, which depends only on the distance D.

The width L of the detection electrodes 6a and 6b on one side is smaller than the width of the detection electrodes 7a and 7b on the other side, and the length direction is X.
It is formed so as to have the same overlap length Xo at rest when displaced in the axial direction in opposite directions.
The capacitances Cma and Cmb between the first detection electrode pair 6a and 7a and between the second detection electrode pair 6b and 7b as
Assuming that the X-direction displacement of the cantilever 2 in the X-direction from the rest position is ΔX, Cma = εL
(Xo−ΔX) / D, Cmb = εL (Xo + ΔX) / D
Becomes Therefore, between the electrodes 6a, 7a and between the electrodes 6b,
The difference ΔCm in capacitance between the capacitors 7b is ΔCm = Cmb−Cm
a = 2εLΔX / D, and the X-direction displacement ΔX of the cantilever 2
Is proportional to

FIG. 4 is a manufacturing process diagram of the angular velocity sensor.
1 shows an example of a detection unit in which a cantilever 2 is formed by laminating a thin film on a Si substrate 1 using a surface micromachining technique. First, in the step (A), a first silicon oxide film (hereinafter, referred to as an SiO ₂ film) to be an insulating layer on the Si substrate 1
40a is formed by a CVD method, and in step (B), a metal electrode such as Al is laminated on the first SiO ₂ film 40a by a vapor deposition method or a sputtering method, and the electrodes 5, 7a, 7b are formed.
To form

Next, in the step (C), the cantilever 2 and the Si substrate 1
Poly-Si layer 4 as a sacrificial layer forming a gap with
1 is laminated by CVD method except for the holding portion 3a of the cantilever 2, and electrodes 4, 6a, 6b are formed on the first poly-Si layer 41 in a step (D) in the same manner as in the step (B). In step (E), a second SiO ₂ film 40b for forming a lower layer of the cantilever 2 is laminated thereon by using a mask having a planar outer shape shown in FIG.

Further, in the step (F), the second SiO
_2nd poly-Si to be the center layer of the cantilever 2 on the ₂ film 40b
The layer 42 is laminated using a mask having a slightly smaller area than the above mask, and the third SiO ₂ film 40c is wrapped in the step (G) again using the mask of the step (E) to cover the second poly-Si layer 42. To form an upper layer of the cantilever 2.

Finally, in the step (H), the first poly-Si layer 41, which is a sacrificial layer, is selectively etched by an etchant such as an HF aqueous solution to form a gap 43 serving as a drive and detection capacitance portion.
Is formed, and the cantilever 2 having the support piece 3 on the holding portion 3a side is manufactured.

According to such a method, for example, a minute angular velocity detecting portion having a width of several tens μm, a length of several hundreds μ, and a thickness of several μm or less can be manufactured, and the gap forming the capacitance portion can vibrate. There is an advantage that the structure is simple and the number of steps can be reduced because only one side of the piece is provided.

In the above embodiment, the sacrificial layer and the central layer of the resonator element are formed of poly-Si, and the outer shell and the electrode insulating layer of SiO ₂ are formed of SiO ₂ . The center layer may be formed of SiO ₂ , and the outer shell of the resonator element and the electrode insulating layer may be formed of poly-Si. However, in this case, P-doped poly-Si to which a P-type impurity is added at a high concentration is used for the poly-Si in contact with the metal electrode in order to increase the insulating property. Furthermore, S
A silicon nitride film (Si ₃ N ₄ film) may be used instead of iO _{2, and} a substrate of another material such as a sapphire substrate may be used instead of the Si substrate 1.

Further, in the above embodiment, an example is shown in which the cantilever 2 is formed by laminating a thin film on the substrate 1 using the surface micromachining technology, but a similar structure is obtained using the bulk micromachining technology. You can do things.

For example, although not shown, a portion of the Si substrate 1 facing the cantilever 2 is etched to form a step which becomes the gap 43, and the electrodes 5, 7a, 7b are placed on the lower part of the step by n-type impurities. The lower member formed by doping, metal deposition, or the like, and the upper member cut out into the shape of the cantilever 2 by etching the electrodes 4, 6a, 6b on another Si substrate after forming the electrodes 4, 6a, 6b in the same manner, and the like. The method can also be used.

In this method, the size of the cantilever 2 cannot be made as small as that of the thin film lamination method, but there is an advantage that the structure is simpler and the number of steps can be reduced as compared with the thin film lamination method.

Next, an angular velocity detecting device having an angular velocity sensor according to this embodiment will be described with reference to FIG. In the figure, 50 is a drive circuit connected to the drive electrodes 4 and 5,
51 is a power supply circuit connected to the detection electrodes 6a and 6b, 52
a is a first capacitance / voltage conversion circuit connected to the first detection electrode pair 6a, 7a, and 52b is a second detection electrode pair 6b, 7
A second capacitance / voltage conversion circuit connected to b, 53 is an addition circuit, 54 is a drive control circuit, 55 is a differential circuit, 56 is a detection circuit, and 57 is an output adjustment circuit. Q is the detection electrode 6
3A and 3B show detection capacitance portions between a and 7a and between 6b and 7b. R is an angular velocity detection circuit.

Next, the operation will be described. First, the driving circuit 50 applies an alternating voltage between the driving electrodes 4 and 5, generates a driving force Fd between the driving electrodes 4 and 5, and moves the cantilever 2 in the Y direction in FIG. Vibrate. At this time, the displacement due to the driving in the Y direction is given by Y in the above equation, k1 is a constant determined by the spring rigidity, equivalent length, and the like of the cantilever 2 and its supporting piece 3, and k2 is the driving voltage Vo, driving voltage It is a constant determined by the distance D between the electrodes and the facing area S.

The detection electrodes 6a, 7 are caused by the Y-direction vibration.
a and the capacitances Cma, C between the detection electrodes 6b, 7b.
mb changes according to the change in the electrode interval D. Such changes in the capacitances Cma and Cmb are detected by the respective capacitance / voltage conversion circuits 52a and 52b by a minute detection current supplied to the respective capacitances from the power supply circuit 51, and the voltages Vma and Vma respectively.
mb.

In this state, when the angular velocity Ω acts on the axis of the cantilever 2, that is, around the Z-axis in the figure, the equivalent mass m of the cantilever 2 is expressed by the above equation in the X-axis direction in the figure. Coriolis force Fc acts. Due to this Coriolis force Fc, the cantilever 2 depends on the rigidity of the support piece 3 in the X-axis direction and X
And the vibration displacement ΔX is proportional to the angular velocity Ω. When the cantilever 2 vibrates and displaces in the X-axis direction, the capacitance C
ma and Cmb change as shown in the above equation, and the capacitance difference ΔCm is proportional to the vibration displacement ΔX, that is, the angular velocity Ω, as shown in the above equation.

Here, the voltages Vma and Vmb corresponding to the respective capacitances Cma and Cmb are added by an adding circuit 53.
Voltage (Vma + Vm) corresponding to vibration amplitude ΔD of cantilever 2
b) is obtained, and the drive control circuit 54 performs feedback control of the drive circuit 50 so that the addition result becomes a predetermined constant value, so that the Y-direction vibration velocity v _{Y of} the cantilever 2 represented by the above equation is always constant. controls such that a value v _C, differential circuit 5 a voltage ΔVm (= Vma-Vmb) corresponding to a difference between the electrostatic capacitance
Calculate with 5.

Further, the detection circuit 56 detects the signal based on the signal from the drive circuit 50 to obtain the X-direction vibration displacement ΔX proportional to the angular velocity Ω, and the output adjustment circuit 57 amplifies the vibration so as to have an appropriate output range. , As an angular velocity signal VΩ. Here, the feedback signal for controlling the driving speed v _Y (Vma
+ Vmb) does not depend on ΔX and is not affected by the Coriolis force Fc.

In this embodiment, since the direction of the electric field between the drive electrodes coincides with the direction of the vibration caused by the drive, there is an advantage that the electrostatic force in the Y direction with respect to the drive voltage is large, and the angular velocity detection sensitivity / drive voltage ratio is large. Further, unlike the related art, since the thickness and the cross-sectional area of the cantilever 2 are not related to the detection sensitivity, there is an advantage that the cantilever 2 can be made thin and small. Further, since there is no component superposition of the driving force Fd on the Coriolis force Fc at the time of vibration in the X-axis direction as in the related art, the angular velocity Ω can be accurately detected.

Embodiment 2 FIG. FIG. 6 shows another embodiment of the angular velocity sensor. In this embodiment, the detecting capacitance portion Q between the detecting electrodes 6a and 7a and between the detecting electrodes 6b and 7b is different from the first embodiment in that the tip side of the cantilever 2 is different. It is arranged in. According to this embodiment, since the distance from the supporting piece 3 that bends and vibrates in the X-axis direction to the detection capacitance portion Q can be long, the displacement X in the X-axis direction of the detection electrode during vibration becomes large, and the detection electrode The difference ΔCm in the inter-capacitance Q increases, and the angular velocity detection sensitivity can be further improved.

Embodiment 3 FIG. FIG. 7 shows still another embodiment of the angular velocity sensor, and here shows an example in which the detection electrode on one side is shared. In the figure, reference numeral 8 denotes a common detection electrode in which the above-described detection electrodes 6a and 6b arranged on the cantilever 2 are combined into one, and are connected to the power supply circuit 51 and the capacitance / voltage conversion circuits 52a and 52b in FIG. And a difference ΔCm in capacitance formed between the common detection electrode 8 and the detection electrodes 7a and 7b.
Detects the angular velocity Ω.

That is, according to this embodiment, since one of the detection electrodes is shared, the number of leads passing through the support piece 3 can be reduced, wiring can be simplified, and masking during electrode formation can be simplified. There is an advantage that the influence of stray capacitance between them can be reduced.

Embodiment 4 FIG. FIG. 8 shows still another embodiment of the angular velocity sensor. Here, an example is shown in which the drive electrode and the detection electrode on one side are shared. In the figure, reference numeral 9 denotes the above-described drive electrode 4 and detection electrode 6 arranged on the cantilever 2.
a, 6b is a common electrode that is integrated into one. Although not shown, the common electrode 9 is connected to the ground, and the drive electrode 5 on the other side is connected.
Is connected to the drive circuit 50, and the other detection electrodes 7a and 7b are connected to the power supply circuit 51 and the capacitance / voltage conversion circuits 52a and 52b, respectively. In this embodiment, there is an advantage that the wiring can be further simplified and the masking at the time of forming the electrodes can be further simplified.

Embodiment 5 FIG. FIG. 9 shows another embodiment of the angular velocity sensor, in which an example in which a support piece is provided in the middle of a cantilever is shown. In the figure, reference numeral 21 denotes a flat plate-like cantilever base as a part of a cantilever 2 which is disposed in parallel and close to the Si substrate 1 and mainly bends and deforms in the vertical direction with respect to the Si substrate 1.
22 is a plate-like cantilever tip as a part of the cantilever 2 which is similarly rigid with respect to bending and disposed close to and parallel to the Si substrate 1, and 31 is a cantilever base 21 and a cantilever tip 22. Knot A support piece that bends and deforms in the horizontal direction. The cantilever base 21 is integrally connected to the holding portion 21a that supports the cantilever base.

The driving electrode 4 is formed of Si
The detection electrodes 6 a and 6 b are provided on the surface facing the substrate 1, and the detection electrodes 6 a and 6 b are provided on the surface of the cantilever tip portion 22 facing the Si substrate 1.
The driving electrodes 4 and the detection electrodes 7a and 7b on the other side are disposed on the Si substrate 1 so as to correspond to the driving electrodes 4 and the detection electrodes 6a and 6b, respectively.

In this embodiment, an alternating voltage is applied between the drive electrodes 4 and 5 to oscillate the cantilever base 21 in the vertical direction (Y direction) with respect to the Si substrate 1 and to move the cantilever tip 22 in conjunction therewith. To vibrate in the Y direction. When the angular velocity Ω acts around the axis G of the resonator element 2 in this state, the cantilever tip 2
Since 2 is displaced and vibrated by Coriolis force in the X-axis direction due to the X-direction bending elasticity of the support piece 31, the capacitance between the detection electrodes 6a and 7a and between the detection electrodes 6b and 7b change mutually. Therefore,
Similarly, the angular velocity Ω can be detected from the difference in capacitance by using the detection circuit shown in FIG.

In this embodiment, the cantilever base 21
Does not vibrate in the X-axis direction, so that vibration modes can be separated, and the degree of freedom in dimensional design of the resonator element 2 is increased.

Embodiment 6 FIG. FIG. 10 shows still another embodiment of the angular velocity sensor cantilever detecting unit. Here, the driving electrode 4 of the cantilever base 21 which is a part of the cantilever 2 and a part of the cantilever 2 are shown. The detection electrodes 6 a and 6 b of the cantilever tip 22 are collectively used as the common electrode 9. In this embodiment, the angular velocity Ω can be detected as in the fifth embodiment, and the same effects as in the fourth embodiment can be obtained.

Embodiment 7 FIG. FIG. 11 shows an embodiment in which the detection unit of the angular velocity sensor according to the present invention is a doubly supported beam.
A plate-shaped doubly-supported beam 32 as a vibrating reed that bends and deforms mainly in the vertical direction with respect to the substrate 1, connects both ends of the doubly-supported beam 23 and each holding portion 32 a, and is perpendicular to the Si substrate 1. It is a support piece that bends and deforms in the horizontal direction.

The detection electrodes 6a and 6b are arranged symmetrically with respect to the axis G of the doubly supported beam 23 at the center of the surface of the doubly supported beam 23 facing the Si substrate 1, and the drive electrode 4 sandwiches the detection electrodes 6a and 6b. It is provided separately on both ends of the cantilever 23. The detection electrodes 7a and 7b on the other side and the drive electrode 5 on the other side are respectively provided on the Si substrate 1 in the same manner as in the first embodiment.
6b and 4 are disposed opposite to each other. It should be noted that such an angular velocity sensor can also be manufactured in the same manufacturing process as in FIG.

The detection of the angular velocity Ω is performed by using the detection circuit shown in FIG. 5, and the same drive voltage is applied to the separated drive electrodes 4 and 5. This embodiment has the same effect as the first embodiment, and is advantageous in that mechanical strength against impact can be obtained.

Embodiment 8 FIG. FIG. 12 shows another embodiment in which the detection unit of the angular velocity sensor is a doubly supported beam.
Similarly to FIG. 11, an example is shown in which the drive electrode 4 and the detection electrodes 6a, 6b on the doubly supported beam 23 side in FIG. In this example, the drive electrodes 5 separated to the left and right on the Si substrate 1 side are further connected at the center to be integrated. In this embodiment, similar to the fourth embodiment, simplification of lead wiring and simplification of masking at the time of molding can be realized.

In the third, fourth, sixth, and eighth embodiments, the electrodes are shared by the electrodes on the cantilever 2 and the double-supported beams 23, which are the vibrating bars. But Si
It may be performed with the electrode on the substrate 1 side. However, it is more effective to use a common electrode on the vibrating piece because the number of electrode leads passing through the narrow support piece is reduced.

Embodiment 9 FIG. FIGS. 13 and 14 show another embodiment of the angular velocity sensor according to the present invention.
Indicates a cantilever detecting section, and FIG. 14 is a block diagram of an angular velocity detecting device having the angular velocity sensor.

In FIG. 13, reference numerals 14a and 14b denote a cantilever 2 which is a vibrating reed, on the opposite side of the cantilever 2 formed on the Si substrate 1 so as to be close to the same as in the first embodiment. The drive detection electrodes 15a and 15b as one side common electrodes symmetrically arranged with respect to the axis G, and the other side common electrodes as opposed to the drive detection electrodes 14a and 14b on the Si substrate 1 corresponding to the drive detection electrodes 14a and 14b, respectively. It is a drive detection electrode.

Here, one of the drive detection electrodes 14a, 14
b is the drive detection electrode 15 on the other side as in the case of the first embodiment.
a and 15b are formed so as to be shifted from each other in the X-axis direction in the X-axis direction, and each of the drive detection electrodes 14a and 15a constituting the drive detection capacitance portion S with respect to the displacement of the cantilever 2 in the X direction.
a and the capacitance difference Δ between the drive detection electrodes 14b and 15b.
Cm is the X-direction displacement ΔX of the cantilever 2 as shown in the above equation.
So that it is proportional to

In FIG. 14, the drive detection electrode 1
4a and 14b are connected to the drive circuit 50, the drive detection electrodes 14a and 15a are connected to the capacitance / voltage conversion circuit 52a, and the drive detection electrodes 14b and 15b are connected to the second capacitance / voltage conversion circuit 52.
b. First, the drive circuit 50 is connected between the drive detection electrodes 14a and 15a and between the drive detection electrodes 14b and 15b.
An in-phase alternating voltage is applied between the electrodes to generate a driving force Fd between the electrodes, and the cantilever 2 is vibrated at its resonance frequency in the Y direction in the figure.

In such a state, when an angular velocity Ω acts around the Z axis, the cantilever 2 is rotated in the X direction by the Coriolis force Fc acting on the cantilever 2 depending on the rigidity of the support piece 3 in the X axis direction. Oscillation occurs with a displacement ΔX proportional to Ω, and a capacitance difference ΔCm expressed by the above equation occurs between the electrodes. Here, voltages Vma, Vmb corresponding to the respective capacitances Cma, Cmb are:
The addition is performed by the addition circuit 53, and the drive control circuit 54 performs feedback control of the drive circuit 50 so that the addition result becomes a predetermined constant value, and the Y-direction vibration velocity v _{Y of the} cantilever 2 expressed by the above equation is obtained.
Is always controlled to a constant value v _C.

A voltage ΔVm corresponding to the capacitance difference ΔCm is obtained by a differential circuit 55, a detection circuit 56 performs detection based on a signal from the drive circuit 50, and an output adjustment circuit 57 appropriately detects the voltage ΔVm. And output as an angular velocity signal VΩ. Here, the feedback signal Vma + Vmb for controlling the drive speed v _Y does not depend on ΔX and is not affected by the Coriolis force Fc, as in the first embodiment. According to such an embodiment, the same effect as in the first embodiment can be obtained.
Since the number of electrodes is small, there are advantages that the number of leads can be reduced, wiring can be simplified, masking at the time of forming electrodes can be simplified, and stray capacitance between leads can be reduced.

Although not shown, the drive detection electrodes 14a,
By sharing 14b, the number of electrodes can be further reduced.

Embodiment 10 FIG. FIG. 15 shows another embodiment of the angular velocity sensor of the doubly supported beam. Here, FIG.
And a common drive detection electrode 16 in which the drive detection electrodes 14a and 14b are shared, and are disposed symmetrically with respect to the axis G of the doubly supported beam 23 on the Si substrate 1 opposed thereto. Drive detection electrodes 15a and 15b corresponding to the common electrode 16 are provided. This embodiment also has the same effects as the ninth embodiment, and is advantageous in terms of mechanical strength against impacts because it is a doubly supported beam.

Embodiment 11 FIG. FIG. 16 shows an embodiment of an angular velocity sensor for simultaneously detecting two-axis angular velocities.
A substantially square rectangular vibrating piece as a vibrating piece that is disposed close to and parallel to the substrate 1 and that is mainly bent and deformed in the vertical direction with respect to the Si substrate 1 is provided with a rectangular frame-shaped vibrating piece 33 at each of four corners of the rectangular vibrating piece 24. The support piece is provided so as to communicate with the holding portion 33a, and is bent and deformed in the horizontal direction with respect to the Si substrate 1 and expands and contracts in the length direction. The drive electrode 5 on the side of the Si substrate 1 is arranged at a position facing the center of the rectangular vibrating piece 24, and the detection electrodes 7a, 7b, 7c, 7d are arranged adjacent to each side of the drive electrode 5, The drive and detection electrodes on the side of the rectangular resonator element 24 are shared as the common electrode 9. A drive capacitance portion P is formed by the drive electrode 5 and the common electrode 9, and the four detection electrodes 7 a, 7 b, 7 c, 7 d and the common electrode 9 make a point with respect to the center axis O of the rectangular resonator element 24. Four pairs of symmetric detection capacitance portions Q are formed.

The common electrode 9 covers the drive electrode 5 so that the drive capacitance between the drive electrode 5 and the common electrode 9 is invariant with respect to the vibration in the X and Y directions. And the capacitance between the detection electrode 7b and the common electrode 9 is X
Each of the detection electrodes 7a, 7b, 7 has a capacitance such that the capacitance between the detection electrode 7c and the common electrode 9 and between the detection electrode 7d and the common electrode 9 change with respect to the vibration in the Y direction.
The rectangular vibrating reed 24 of c and 7d is formed as shown in FIG.

That is, the displacement ΔX of the rectangular vibrating piece 24 in the X direction
For the detection electrode 7a, between the common electrode 9 and the detection electrode 7
b, only the capacitance difference ΔCmx between the common electrodes 9, and only the difference ΔCmy between the detection electrodes 7 c and the common electrodes 9 and between the detection electrodes 7 d and the common electrodes 9 for the Y-direction displacement ΔY. , Respectively.

Although not specifically shown, the detection circuit is the same as that shown in FIG. 5, and is implemented by the capacitance / voltage conversion circuits 52a and 52b connected to the detection electrodes 7a and 7b in FIG. In addition to the circuit 56 and the output adjustment circuit 57, another system (not shown), a capacitance / voltage conversion circuit connected to the detection electrodes 7c and 7d, a differential circuit, a detection circuit, and an output adjustment circuit is provided.

In the above configuration, in the state where the driving capacitance unit is driven to resonate the rectangular vibrating reed 24 in the vertical direction (Z direction) with respect to the Si substrate 1, the Y of the rectangular vibrating reed 24 is
When the angular velocities Ωy and Ωx act on the axis and the X axis, respectively, the rectangular vibrating piece 24 is caused to have angular velocities Ω in the X direction and the Y direction by the Coriolis forces Fcx and Fcy acting on the rectangular vibrating piece 24, respectively.
Vibration occurs at displacements ΔX and ΔY proportional to y and Ωx, and the capacitance differences ΔCmx and ΔCmy expressed by the above equation are generated between the electrodes.

Each of the capacitance differences ΔCmx and ΔCmy is a capacitance / voltage conversion circuit 52 as shown in FIG.
a, 52b and other similar capacity / voltage conversion circuits, and differential circuits 55 and a differential circuit (not shown) connected to each group are obtained as voltages ΔVmx, ΔVmy,
Each of the detection circuits similar to that shown in FIG. 5 performs detection based on the signal from the drive circuit to determine the displacements ΔX and ΔY corresponding to the angular velocities Ωy and Ωx in the respective axial directions. Amplification is performed to obtain an appropriate output range, and the angular velocity signal V
Output as Ωy and VΩx. That is, in this embodiment, there is an advantage that the angular velocities of two axes around the horizontal axis can be simultaneously detected.

Embodiment 12 FIG. FIGS. 17 and 18 show another embodiment of the angular velocity sensor for simultaneously detecting the angular velocities of the two axes. FIG. 17 shows a detection unit of the angular velocity sensor.
8 shows a block diagram of a detection circuit of the angular velocity detecting device having the angular velocity sensor. In FIG. 17, the drive detection electrode 1
5 a, 15 b, 15 c, and 15 d are positioned at positions opposing the common drive detection electrode 16 of the rectangular vibrating reed 24 on the Si substrate 1 side.
They are arranged so that the facing area changes with respect to displacement in each of the horizontal axes X and Y.

In FIG. 18, the drive detection electrodes 15a, 15b, 15c and 15d and the common drive detection electrode 1
After the capacitances Cma, Cmb, Cmc, and Cmd between the capacitors 6 are detected by the capacitance / voltage conversion circuits 52a, 52b, 52c, and 52d, respectively, and converted into voltages, each of the addition circuits 53
ma + Cmd, Cmb + Cmc, Cma + Cmb, Cm
c + Cmd is calculated, and the difference ΔCmx, ΔCmy of the pair of the capacitance sums in each differential circuit 55 is ΔCmx = (Cmb
+ Cmc)-(Cma + Cmd) and ΔCmy = (C
ma + Cmb)-(Cmc + Cmd).

On the other hand, the total capacitance sum is calculated by the addition circuit 53A, and the drive control circuit 54 performs feedback control of the drive circuit 50 so that the addition result becomes a predetermined constant value. Control is performed so that the directional vibration speed v _z always becomes a constant value v _C. Here, assuming that displacements of the rectangular vibrating reed 24 depending on the angular velocities Ωy and Ωx from the stationary positions Xo and Yo in the X and Y directions are ΔX and ΔY, respectively, from the above expression, ΔC
mx = 4εYo / D * ΔX, ΔCmy = 4εXo / D *
ΔY, and ΔCmx and ΔCmy are angular velocities Ωy and Ω, respectively.
Since it is proportional to x, the output of each differential circuit 55 is detected by each detection circuit 56 to obtain voltages corresponding to ΔX and ΔY.
Each output adjustment circuit 57 amplifies the output so as to have an appropriate output range, and outputs it as angular velocity signals VΩy and VΩx. According to this embodiment, the same effects as in the eleventh embodiment can be obtained, and the number of electrodes can be reduced. Therefore, the present embodiment is as advantageous as the third embodiment in reducing the number of leads, simplifying masking, and reducing stray capacitance.

In each of the above embodiments, the support pieces 3, 3
Although 1, 32 and 33 are shown as having both vertical bending elasticity and horizontal bending elasticity, they may have shapes having only horizontal bending elasticity.

Embodiment 13 FIG. FIGS. 19 and 20 show an embodiment in which a weight 44 for adjusting the resonance frequency is provided on the cantilever 2. After the step (G) in FIG. , Ag, etc. are formed by evaporating a relatively heavy metal to a predetermined thickness. According to the addition of the weight 44, the weight 44
There is an advantage that the resonance frequency determined by the shape of the cantilever 2 in the case where there is no vibration can be adjusted to an appropriate frequency in consideration of the response and the like. In addition, the individual difference in the resonance frequency can be corrected by gradually reducing the mass of the weight 44 using a mechanical means such as ultrasonic cutting or a chemical means such as partial etching.

In the above embodiment, the weight 44 is connected to the cantilever 2.
Although the case where it is provided is shown, it may be provided at the central part of the above-mentioned doubly supported beam 23 and rectangular vibrating piece 24.

Embodiment 14 FIG. FIGS. 21 and 22 show another embodiment of the present invention. In FIG. 21, reference numeral 1 denotes a silicon substrate (hereinafter, referred to as a Si substrate) as a substrate disposed horizontally in an XZ coordinate plane; A plate-shaped cantilever as a vibrating reed which is disposed close to and parallel to the upper surface which is one surface of the Si substrate 1 and at least a part of which is bent and deformed mainly in a direction perpendicular to the surface of the Si substrate 1, that is, in the Y axis direction. The beam 3 is continuously provided on the cantilever support side of the cantilever 2 in the direction of the axis G.
A support piece that bends and deforms in the horizontal direction and the X-axis direction with respect to the surface of the i-substrate 1.
It is held (fixed) at one end of the i-substrate 1. Therefore,
The cantilever 2 is made of Si so that it can be sensitively vibrated and deformed via the support piece 3.
It will be held on the substrate 1.

4A is a lower electrode 4 on the upper surface of the cantilever 2.
5, a thin piezoelectric element laminated in the order of the piezoelectric film 46 and the upper electrode 47, 6a and 6b are one detection electrodes provided on the free end side of the lower surface of the cantilever 2 which is the free end side, and 7a and 7b are S
The other detection electrodes are provided on the upper surface of the i-substrate 1 so as to face the detection electrodes 6a and 6b, respectively. A first detection electrode pair is formed by 6a and 7a, and a second detection electrode pair is formed by 6b and 7b. , Form a detection capacitance portion Q. In FIG. 21, the direction of vibration is represented by an XZ coordinate system of the X axis and the Z axis, and FIG.
In FIG. 2, the Y-X coordinate system of the Y-axis and the X-axis is used, and the configuration and operation will be described below mainly on these coordinate systems.

Here, the length L of the detection electrodes 6a and 6b along the Z-axis is shorter than the length of the detection electrodes 7a and 7b, and the detection electrodes 6a and 6b are shifted in opposite directions in the X-axis direction to have the same overlap length Xo at rest. Is formed.

Between the detecting electrodes 6a, 7a and the detecting electrode 6
The capacitances Cma and Cmb between b and 7b are equal to X of the cantilever 2.
The magnitude differs depending on the direction displacement, and X
Assuming that the directional displacement is ΔX, the dielectric constant of the medium between the detection electrodes 6a and 7a and between the detection electrodes 6b and 7b is ε, and Cma = εL (Xo + ΔX) / D, Cmb = εL
(Xo−ΔX) / D. Therefore, each detection electrode 6a,
7a and the capacitance difference ΔC between the detection electrodes 6b and 7b
m is ΔCm = Cma−Cmb = 2εLΔX / D, and is proportional to the X-direction displacement ΔX of the cantilever 2.

FIG. 23 is a view showing a manufacturing process of the angular velocity sensor, in which the Si substrate 1 is formed using the surface micromachining technology.
An example in which a thin film is laminated thereon to form a cantilever 2 as a vibrating reed is shown. First, in the step (A), the Si substrate 1
A first silicon oxide film (hereinafter referred to as SiO
₂ of film) 10 is deposited by a CVD method, then, the metal electrode such as Al is laminated by an evaporation method or a sputtering method on the first SiO ₂ film 10, the detection electrodes 7a, 7b
To form

Next, in the step (B), the cantilever 2 and the Si substrate 1
A polysilicon layer (hereinafter, referred to as a poly-Si layer) 11 serving as a sacrificial layer for forming a gap between the polysilicon layer and the support portion 3a of the cantilever 2 is laminated by a CVD method except for the base portion.
The detection electrodes 6a and 6b are laminated on the i-layer 11 in the same manner as in the step (A), and a second layer for forming an electrode insulating layer and forming a lower layer of the skeleton of the cantilever 2 thereon in a step (C). SiO
_{The two} films 12 are laminated using a mask, and in the step (D), a third SiO ₂ film 13 is further laminated on a portion corresponding to the support piece 3 of the cantilever 2 as a reinforcing layer for increasing the strength in the vertical direction.

Next, in the step (E), the second SiO ₂
On the film 12, P is used as the lower electrode 45 of the piezoelectric element 4A.
t, Ti and the like are laminated by a vapor deposition method, and in step (F), zircon / lead titanate (PZ) is formed on the lower electrode 45.
T) or the like is laminated by a sputtering method or a CVD method to form a piezoelectric film 46, and an Al film is further formed thereon.
Are laminated by vapor deposition or the like to form a piezoelectric element 4.
A is formed on the lower layer of the skeleton, and the skeleton of the cantilever 2 is completed.

Finally, in the step (G), the poly-Si layer 11 serving as a sacrificial layer is selectively etched by an etchant such as an HF aqueous solution to form a gap 18 for forming a detection capacitance portion. The cantilever 2 having the support piece 3 on the side is manufactured. According to such a method, for example, the cantilever 2
A small angular velocity detector with a width of several tens of μ, a length of several hundred μ, and a thickness of several μ can be manufactured, and the gap is only on one side of the cantilever 2, so the structure is simple and the number of steps is small. There is an advantage that it can be used.

In the above embodiment, the sacrificial layer made of poly-Si
The lower layer of the skeleton of the cantilever 2 and the electrode insulating layer were formed of iO ₂ , but the sacrifice layer was formed of SiO ₂ , and the lower layer of the skeleton of the cantilever 2 and the electrode insulating layer were formed of polySi, contrary to the embodiment. Is also good. However, in this case, the poly-Si in contact with the electrode is a P-doped poly-Si in which a P-type impurity is added at a high concentration in order to increase the insulating property.
Use Furthermore, a silicon nitride film (Si ₃ N ₄ film) may be used instead of SiO _{2, and} a substrate of another material such as a sapphire substrate may be used instead of the Si substrate 1.

Further, in the above embodiment, an example is shown in which the cantilever 2 is formed by laminating a thin film on the Si substrate 1 using the surface micromachining technology, but a similar structure is formed using the bulk micromachining technology. You can also get. For example,
Although not shown, after the step facing the cantilever 2 of the Si substrate 1 is etched to form a step serving as a gap, the detection electrodes 7a and 7b are applied to the lower part of the step by n-type impurity doping, metal evaporation, or the like. The other detection electrodes 6a and 6b are formed on another Si substrate by the same method, and the piezoelectric element 4A is formed on the opposite surface by the above-described method. It can also be manufactured by a method such as cutting out the shape into an upper member and joining the upper member and the lower member. Here, the piezoelectric element 4A can be formed after the joining, though depending on the joining method.

In this method, the size of the cantilever 2 cannot be made as small as that of the thin film lamination method, but there is an advantage that the structure is simpler and the number of steps can be reduced as compared with the thin film lamination method.

Next, an angular velocity detecting device using such an angular velocity sensor will be described. In FIG. 24, reference numeral 50 denotes a drive circuit connected to the electrodes 45 and 47 of the piezoelectric element 4A;
Reference numeral 1 denotes a power supply circuit connected to the detection electrodes 6a and 6b, 52a
Is a first capacitance / voltage conversion circuit connected to the detection electrodes 6a and 7a, and 52b is a second capacitance / voltage conversion circuit connected to the detection electrodes 6b and 7b.
Is a capacitance / voltage conversion circuit, 53 is an addition circuit, 54 is a drive control circuit, 55 is a differential circuit, 56 is a detection circuit, and 57 is an output adjustment circuit. R is an angular velocity detection circuit.

Next, the operation will be described. Here, the piezoelectric element 4A has been subjected to a polarization process in advance by applying a DC electric field between the electrodes 45 and 47 so that the piezoelectric film 46 is expanded and contracted in the Z-axis direction by a piezoelectric transverse effect. First, the driving circuit 5
Numeral 0 applies an alternating voltage between the electrodes 45 and 47 to apply an alternating electric field to the piezoelectric film 46 to expand and contract the piezoelectric element 4A in the axial direction of the cantilever 2 (Z-axis direction). Since the piezoelectric element 4A is formed above the neutral point of the cantilever 2, the cantilever 2 bends and vibrates at its resonance frequency in the Y-axis direction in FIG. Detection electrodes 6a, 7
a and the capacitances Cma, C between the detection electrodes 6b, 7b.
mb changes in the same phase according to the change of the electrode interval D.

The changes in the capacitances Cma and Cmb are detected by the respective capacitance / voltage conversion circuits 52a and 52b by a minute detection current supplied from the power supply circuit 51 to the respective capacitances, and are changed to the voltages Vma and Vmb, respectively. Is converted. In such a state, when an angular velocity Ω acts on the axis of the cantilever 2, that is, around the Z-axis in the figure, the Coriolis force expressed by the above equation in the X-axis direction in the figure as its equivalent mass m is applied to the cantilever 2. Fc works. Due to this Coriolis force Fc, the cantilever piece 2 vibrates in the X direction depending on the rigidity of the support piece 3 in the X-axis direction, and the vibration displacement ΔX is proportional to the angular velocity Ω.

When the cantilever 2 vibrates and displaces in the X-axis direction, the capacitances Cma and Cmb change as the vibration displacement Δ
It changes in the opposite phase due to X, and the capacitance difference ΔCm is proportional to the vibration displacement ΔX, that is, the angular velocity Ω, as shown in the above equation. Here, a voltage Vma, which corresponds to each of the capacitances Cma, Cmb,
Vmb is added (Vma + Vmb) by the adder circuit 53 to detect the in-phase drive amplitude, and the drive control circuit 54 sets the drive circuit 5 so that the differential value of the drive amplitude becomes a predetermined constant value.
0 is feedback-controlled so that the Y-direction vibration velocity v _{Y of} the cantilever 2 represented by the above equation always becomes a constant value v _C.

On the other hand, the capacitance difference Δ proportional to the angular velocity Ω
An opposite-phase voltage ΔVm (= Vma−Vmb) corresponding to Cm is obtained by a differential circuit 55, a detection circuit 56 performs detection based on a signal from the drive circuit 50, and an output adjustment circuit 57 outputs an appropriate output range. And output as an angular velocity signal VΩ. Here, the feedback signal Vma + Vmb for controlling the driving speed v _Y does not depend on ΔX according to the above equation, and is not affected by the Coriolis force Fc.

In this embodiment, the cantilever 2 is vibrated by the expansion and contraction of the piezoelectric element 4A, and the drive voltage with respect to the drive amplitude can be smaller than that in the conventional electrostatic drive. There is an advantage that the sensitivity / drive voltage ratio is large. Further, unlike the conventional case, the thickness and the cross-sectional area of the cantilever 2 do not relate to the detection sensitivity.
There is also an advantage that it can be made small. Further, since there is no component superposition of the driving force Fd on the Coriolis force Fc at the time of vibration in the X-axis direction as in the related art, the angular velocity Ω can be accurately detected.

Embodiment 15 FIG. FIG. 25 is a plan view showing another embodiment of the angular velocity sensor according to the present invention. This shows an example of a doubly supported beam in which the detection unit is a vibrating reed.
A is a flat plate-like doubly supported beam (vibrating piece) which is arranged in parallel and close to the Si substrate 1 and has bending elasticity only in a direction perpendicular to the paper surface;
A is a support piece that is connected to the support side of the doubly supported beam 23A and has bending elasticity in the direction perpendicular to the plane of the drawing and also has bending elasticity in the horizontal direction. A support 32a is supported through the support piece 32A. This is a holding unit that holds the beam 23A.

Reference numeral 6A denotes a common electrode which is arranged at the center of the doubly supported beam 23A and shares the detection electrodes 5a and 5b.
The detection electrodes 7a and 7b on the i-substrate 1 are arranged symmetrically with respect to the axis of the doubly supported beam 23A at a position facing the common electrode 6A. By sharing one detection electrode 6a, 6b on one side as described above, the mask pattern at the time of electrode formation can be simplified and the number of lead wires can be reduced. Here, a pair of capacitance parts is provided symmetrically with respect to the center vertical plane E in the width W direction of the doubly supported beam 23A.

Such an angular velocity sensor can be manufactured in the same manufacturing process as in FIG. 23, and the detection of the angular velocity Ω is similarly performed in FIG.
Is performed by using the detection circuit of (1). This embodiment has the same effect as the fourteenth embodiment, and is advantageous in mechanical strength against impact.

Embodiment 16 FIG. FIG. 26 is a plan view showing still another embodiment of the angular velocity sensor according to the present invention. This shows an example in which the support piece 31 is provided in the middle of the cantilever (vibrating piece) 2A. In the figure, reference numeral 21 denotes a flat plate-like cantilever base which is arranged close to and parallel to the Si substrate 1 and has bending elasticity only in a direction perpendicular to the paper surface. High flat cantilever tip,
Reference numeral 31 denotes the above-described support piece that connects the cantilever base 21 and the cantilever tip 22 and has bending elasticity in the horizontal direction. The piezoelectric element 4A is provided on the upper surface of the cantilever base 21 closer to the holding section 21a than the support piece 31. The common electrode 6A is provided on the lower surface of the cantilever tip 22, and the detection electrodes 7a and 7b are provided on the upper surface of the Si substrate 1 facing the common electrode 6A. And
A pair of capacitance portions each including the common electrode 6A and the detection electrodes 7a and 7b are provided symmetrically with respect to the center vertical plane E in the width direction of the cantilever 2A.

In this embodiment, the piezoelectric element 4A is driven to vibrate the cantilever base 21 in the direction perpendicular to the paper surface (Y direction), and the cantilever tip 22 is similarly vibrated in the Y direction in conjunction with this. . When an angular velocity Ω acts around the axis of the vibrating piece 2A in this state, the cantilever tip 22 is displaced and vibrated by the Coriolis force in the X-axis direction due to the X-direction bending elasticity of the support piece 31, so that the detection electrode 7a and the common electrode Between 6A and detection electrode 7
b, each capacitance between the common electrodes 6A changes mutually.

Therefore, similarly, the angular velocity Ω can be detected from the difference in capacitance by using the detection circuit shown in FIG. In this embodiment, since the cantilever base 21 does not vibrate in the X-axis direction, vibration modes can be separated, and there is an advantage that the degree of freedom in dimensional design of the vibrating piece 2A as the cantilever is increased.

In the embodiments 15 and 16, the case where the electrodes are shared by the electrodes on the doubly supported beam 23A and the cantilever beam 2A is shown. You may. However, it is more effective to use a common electrode on the side of each of the beams 23A and 2A because the number of electrode leads passing through the narrow support piece is reduced.

Embodiment 17 FIG. FIG. 27 shows an angular velocity sensor that detects angular velocity of two axes at the same time.
A rectangular vibrating piece as a substantially square vibrating piece which is disposed in parallel with the i-substrate 1 and has bending elasticity only in a direction perpendicular to the plane of the drawing, 33 is a rectangular frame-shaped holding portion at the four corners of the rectangular vibrating piece 24. The support piece is provided so as to be in communication with 33a, and has bending elasticity in the horizontal direction with respect to the plane of the drawing and elasticity in the longitudinal direction.
Here, the piezoelectric element 4 </ b> A has a square piezoelectric element polarized so as to expand and contract from the center toward the periphery and is arranged symmetrically on the upper surface of the rectangular vibrating piece 24.

On the other hand, on the lower surface of the rectangular vibrating piece 24, a square common electrode 6A is also arranged symmetrically with respect to the center, and on the Si substrate 1, at a position corresponding to the common electrode 6A, on each side of the common electrode 6A. The detection electrodes 7a, 7b, 7c, 7d are arranged along the axis, and the capacitance between the detection electrode 7a and the common electrode 6A and between the detection electrode 7b and the common electrode 6A in one horizontal axis direction F is not affected by the vibration in the X direction. , Detection electrode 7c, common electrode 6A
The capacitance in the other horizontal axis direction G orthogonal to the one horizontal axis direction F between the detection electrode 7d and the common electrode 6A is variable with respect to the vibration in the Y direction. Further, each detection electrode 7a, 7b, 7c, 7d and the common electrode 6A
Thus, four detection capacitance portions that are point-symmetric with respect to the center axis O of the rectangular vibrating piece 24 are formed.

That is, the displacement ΔX in the X direction of the rectangular vibrating piece 24
Between the detection electrode 7a and the common electrode 6A and the detection electrode 7
b, only the capacitance difference ΔCmx between the common electrodes 6A is Y
For the directional displacement ΔY, a difference ΔCm in capacitance between the detection electrode 7c and the common electrode 6A and between the detection electrode 7d and the common electrode 6A.
Only y is proportional to each other.

Although the detection circuit is not particularly shown, it is performed by using the same one as that shown in FIG. 24, and the detection electrodes 7a and 7 shown in FIG.
b, in addition to the capacitance / voltage conversion circuits 52a and 52b, the differential circuit 55, the detection circuit 56, and the output adjustment circuit 57 connected to
Another system is provided with another capacitance / voltage conversion circuit, a differential circuit, a detection circuit, and an output adjustment circuit connected to the detection electrodes 7c and 7d.

In this embodiment, when the piezoelectric element 4A is driven, it expands and contracts from the center of the piezoelectric element 4A to the surroundings.
The rectangular vibrating reed 24 vibrates at a resonance frequency in a direction perpendicular to the paper surface (Z direction). In this vibration state, when the angular velocities Ωy and Ωx respectively act around the Y and X axes of the rectangular vibrating piece 24, the Coriolis forces Fcx and Fc acting on the rectangular vibrating piece 24
With y, the rectangular vibrating piece 24 vibrates in the X direction and the Y direction with displacements ΔX and ΔY proportional to the angular velocities Ωy and Ωx, respectively, and the capacitance differences ΔCmx and ΔCmy shown between the electrodes are generated.

The capacitance differences ΔCmx and ΔCmy are respectively determined by the capacitance / voltage conversion circuits 52a and 52b, a capacitance / voltage conversion circuit (not shown) of another system, a differential circuit 55 connected to each system, and the like. After being detected by the detection circuit 56 and the like based on the signal from the drive circuit 50, the signals are amplified by the output adjustment circuits 57 and the like so as to have an appropriate output range, and the angular velocity signals VΩy and VΩy are obtained.
Output as Ωx. That is, in this embodiment, there is an advantage that the angular velocities of two axes around the horizontal axis can be simultaneously detected.

Embodiment 18 FIG. FIG. 28 shows another embodiment of an angular velocity sensor for simultaneously detecting two axes of angular velocity. FIG. 28 shows a detecting section of the angular velocity sensor, and FIG. 29 shows a detecting circuit of an angular velocity detecting device having this angular velocity sensor. It is a block diagram. In FIG. 28, detection electrodes 7a, 7b, 7
c and 7d are provided on the upper surface of the Si substrate 1, and a common electrode 6A is provided on the lower surface of the rectangular vibrating piece 24. These electrodes are arranged at positions where the capacitance changes with respect to the displacement in each of the horizontal axis directions F and G. ing. Therefore, between the rectangular vibrating reed 24 and the Si substrate 1, four pairs of capacitance parts which are horizontally oscillated and point-symmetric with respect to the central axis of the rectangular vibrating reed are formed.

In FIG. 29, each detection electrode 7a,
7b, 7c, 7d and the capacitance Cma between the common electrode 6A.
Cmb, Cmc, and Cmd are each a capacitance / voltage conversion circuit 52
a, 52b, 52c, and 52d are detected and converted into voltages, and then, in each of the adders 53, Cma + Cmd, Cmb
+ Cmc, Cma + Cmb, Cmc + Cmd are calculated.
ΔCmx = (Cmb + Cmc) − (Cma + Cmd),
ΔCmy = (Cma + Cmb) − (Cmc + Cmd) is calculated.

The sum of the total capacitance is calculated in the addition circuit 53, and the drive control circuit 54 feedback-controls the drive circuit 50 so that the differential value of the addition result becomes a predetermined constant value.
The Z direction vibration velocity v _z of the rectangular vibrating piece 24 is always a constant value v
The driving of the piezoelectric element 4A is controlled so as to be _C.

Here, assuming that displacements of the rectangular vibrating reed 24 depending on the angular velocities Ωy and Ωx from the stationary positions Xo and Yo in the X and Y directions are ΔX and ΔY, respectively, from the above equation, ΔC
mx = 4εYo / D * ΔX, ΔCmy = 4εXo / D *
ΔY, and ΔCmx and ΔCmy are angular velocities Ωy and Ω, respectively.
Since the output is proportional to x, the output of each differential circuit 55 is detected by each detection circuit 56, and then amplified by each output adjustment circuit 57 so as to have an appropriate output range, and the angular velocity signals VΩy, VΩx
Output as

According to this embodiment, the same effects as those of the seventeenth embodiment can be obtained, and the S / N ratio of detection can be increased because the electrode area can be increased.

In the embodiments 17 and 18, the case where the piezoelectric element 4A has a square shape is shown, but a circular shape may be used.

In each of the above embodiments, the support pieces 3, 31, and 33 are shown as having both vertical bending elasticity and horizontal bending elasticity. Good.

Embodiment 19 FIG. FIG. 30 is a sectional view showing an angular velocity sensor in which a cantilever 2 is provided with a weight 44 for adjusting the resonance frequency. Here, the weight 15 is formed by depositing a relatively heavy metal such as Cu or Ag to a predetermined thickness on the tip of the cantilever 2 after the step (E) or (F) in FIG. .

According to the addition of the weight 44, the weight 4
The resonance frequency determined by the shape of the cantilever 2 when there is no
There is an advantage that the frequency can be adjusted to an appropriate frequency in consideration of responsiveness and the like. The individual difference in the resonance frequency can be corrected by gradually reducing the mass of the weight 44 using a mechanical means such as ultrasonic cutting or a chemical means such as partial etching.

In the above embodiment, the weight 44 is connected to the cantilever 2
Is shown, but the doubly supported beam 2A, the rectangular vibrating piece 2
4 may be provided at the center. In such a case, the weight 44 is placed on the upper surface of the upper electrode 47 of the piezoelectric element 4A.
It is formed after the step (F) in FIG. In this case, the upper electrode 47 and the weight 44 may be formed using the same metal.

Embodiment 20 FIG. FIG. 31 is a plan view showing an angular velocity sensor according to another embodiment of the present invention, FIG. 32 is a sectional view taken along line EE of FIG. 31, and FIG. 33 is a manufacturing process diagram of the angular velocity sensor. FIG. 34 shows a manufacturing process as viewed along the line FF, and FIG. 34 is a block diagram of a detection circuit of the angular velocity sensor.

In FIGS. 31 and 32, reference numeral 1 denotes a Si substrate, and 2 denotes an upper surface which is one side of the Si substrate 1 and is arranged in parallel with and close to the upper surface of the Si substrate 1. That is, the elongated plate-shaped cantilever 3 serving as a vibrating reed that bends and deforms in the X-axis direction is provided on the holding portion 3a side of the cantilever 2 in the direction of the axis G, and the bending elasticity in the direction perpendicular to the surface of the Si substrate 1 The support piece has a coefficient smaller than a bending elastic coefficient in the horizontal direction with respect to the Si substrate 1 surface.
The holding portion 3 a continuous with the support piece 3 is held at one end of the Si substrate 1.

4B shows a lower electrode 45a on the upper surface of the cantilever 2;
45b, a piezoelectric film 46, and upper electrodes 47a and 47b.
b and the upper electrodes 47 a and 47 b are arranged symmetrically with respect to the center vertical plane of the cantilever 2, that is, parallel and symmetric with respect to the vertical plane of the axis G of the cantilever 2. By laminating the piezoelectric elements 4B, the cantilever 2 forms a slender columnar beam as a whole.

Reference numerals 7a and 7b denote detection electrodes on one side provided on the upper surface of the Si substrate 1. The detection electrodes 7a and 7b face one detection electrode 6 provided on the lower surface on the front side of the cantilever 2 and have the axis G.
Are formed so that the length along the Z-axis is longer than the detection electrode 6, and the width in the X-axis direction is the same length X0 as the overlap width with the detection electrode 6 at rest. I have.

When the capacitance between the detection electrodes 7a and 6 and the capacitance between the electrodes 7b and 6 are Cma and Cmb, respectively, the sum of the capacitances ΣC
m, the capacitance difference ΔCm, and the ratio R of the capacitance difference ΔCm to the sum of the capacitances ΣCm are the length L of the detection electrode 6, the dielectric constant ε of the electrode facing portion, and the displacement ΔX, Y in the X direction. As the stationary position D0 in the direction and the displacement ΔD, ΣCm = Cma + Cmb =
2εLX0 / (D0 + ΔD), ΔCm = Cma−Cmb
= 2εLΔX / (D0 + ΔD), R = ΔCm / ΣCm =
ΔX / X0.

Therefore, the sum ΔCm depends only on the displacement ΔD in the Y direction, and the ratio R depends only on the displacement ΔX in the X direction.

FIG. 33 is a manufacturing process diagram of the angular velocity sensor, and shows an example in which a cantilever 2 is formed by laminating a thin film on a Si substrate 1 using a surface micromachining technique.
First, in step (A), a silicon oxide film (SiO ₂ film) 10 serving as an insulating layer is laminated on a Si substrate 1 by a CVD method, and subsequently, a metal electrode such as Al is deposited on the SiO ₂ film 10 by a vapor deposition method. Alternatively, the detection electrodes 7a and 7b on one side are formed by lamination using a sputtering method.

Next, in the step (B), the cantilever 2 and the Si substrate 1
After a poly-Si layer 11 as a sacrificial layer forming a gap between the layers is laminated by a CVD method while leaving a base portion of the cantilever 2,
The detection electrode 6 is laminated on the poly-Si layer 11 in the same manner as in the step (A), and SiO ₂ which forms an electrode insulating layer and forms a lower layer of the skeleton of the cantilever 2 thereon in the step (C). The film 12 is laminated using a mask having a planar outer shape shown in FIG.
In the step (D), a poly-Si layer 19 serving as the center layer of the cantilever 2 is laminated on the SiO ₂ film 12 using a mask having a slightly smaller area than the above mask, and then the mask of the step (C) is used again. Then, the SiO ₂ film 12 is stacked so as to surround the poly-Si layer 19 to form the upper layer of the skeleton of the cantilever 2.

Further, in the step (E), the SiO ₂ film 1
Pt, Ti, etc. are laminated as the lower electrodes 45a, 45b of the piezoelectric element 4B by vapor deposition on the electrode 2, and in step (F), a piezoelectric material such as zircon / lead titanate PZT is sputtered on the lower electrodes 47a, 47b. Method or CVD
A piezoelectric film 46 is formed by stacking, and upper electrodes 47a and 47b of Al or the like are stacked thereon by vapor deposition or the like to form a piezoelectric element 4B on the upper skeleton layer. The overall width in the X direction is Y. Slender column-shaped cantilever 2 smaller than the thickness in the direction
To complete.

Finally, in step (G), the poly-Si layer 11 as a sacrificial layer is selectively etched by an etchant such as an HF aqueous solution to form a gap 18 serving as a detection capacitance portion.
Thus, the cantilever 2 having the support piece 3 on the holding portion 3a side
Is prepared. According to such a method, for example, a minute angular velocity detector having a beam width, thickness of several tens μm, and a length of several hundred μm or less can be manufactured, and the structure is simple because the gap is only on one side of the cantilever 2. Therefore, there is an advantage that the number of processes can be reduced.

In this embodiment, the sacrifice layer 11 is made of poly-Si.
The has formed the backbone lower layer and the electrode insulating layer cantilever 2 with SiO _2, the sacrificial layer contrary to the embodiment in SiO _2, be formed skeleton lower layer and the electrode insulating layer of the beam in the poly Si good. However,
In this case, P-doped poly-Si to which a P-type impurity is added at a high concentration is used for the poly-Si in contact with the electrode in order to increase the insulating property. Further, a silicon nitride film (Si ₃ N ₄ film) may be used instead of SiO _{2, and} a substrate of another material such as a sapphire substrate may be used instead of the Si substrate 1.

In this embodiment, an example is shown in which a cantilever 2 is formed by laminating a thin film on a substrate 1 using surface micromachining technology, but a similar structure is obtained using bulk micromachining technology. You can do things.

For example, although not shown, a portion of the Si substrate 1 facing the cantilever 2 is etched to form a step which becomes the gap 18, and the electrodes 7a and 7b are doped with n-type impurities in the lower part of the step. The lower member is formed by metal deposition or the like.
After the electrode 6 is formed on the i-substrate in the same manner, it is etched and cut into the shape of the cantilever 2 to form an upper member. After joining the upper member and the lower member, the upper member faces the electrode 6. Alternatively, the piezoelectric element 4B can be manufactured by a method such as the method described above. The piezoelectric element 4B can be formed before joining, depending on the joining method.

In this method, the size of the cantilever 2 cannot be made as small as that of the thin film lamination method, but there is an advantage that the structure is simpler and the number of steps can be reduced as compared with the thin film lamination method.

Next, the operation of the angular velocity detecting device using the angular velocity sensor of this embodiment will be described with reference to FIG. Here, the piezoelectric element 4B is previously connected to the electrodes 45a, 45b and the electrode 4a.
A DC electric field in the same direction is applied between the piezoelectric film 4a and the piezoelectric film 4a.
The polarization process is performed so that 6 expands and contracts by the piezoelectric transverse effect in the Z-axis direction.

In the figure, reference numeral 50 denotes the electrode 4 of the piezoelectric element 4B.
Drive circuits connected to 5a and 47b, the other electrodes 47a and 45b are grounded, 51 is a power supply circuit connected to the detection electrode 6, and 52a and 52b are detection electrodes 7 respectively.
a, 7b, a capacitance / voltage conversion circuit connected to the output of each of the capacitance / voltage conversion circuits 52a, 52b; 55, a capacitance / voltage conversion circuit 52a, 5
2b is a differential circuit to which the output of 2b is connected.

Reference numeral 58 denotes an addition circuit 53 and a differential circuit 55.
, A driving control circuit connected to the output of the dividing circuit 58 and sending a control signal to the driving circuit 50, and 56 connected to the output of the adding circuit 53 and receiving a signal from the driving circuit 50. A controlled detection circuit 57 is an output adjustment circuit to which the output of the detection circuit 56 is connected. The capacitance / voltage conversion circuits 52a and 52b, the addition circuit 53, the detection circuit 56, and the output adjustment circuit 57 constitute an angular velocity detection circuit R.

Next, the operation will be described. First, the drive circuit 50 is connected between the electrodes 45a and 47a and between the electrodes 45b and 47a.
The alternating voltage of the opposite phase is applied between the electrodes b, and the area of the piezoelectric film 46 sandwiched between the electrodes is displaced in the direction of the extension axis Z in opposite directions.

For example, the left electrodes 45b and 47 in FIG.
When the region between b extends in the Z direction, the right electrodes 45a, 45a
7a, the front side of the piezoelectric element 4B is
As shown in FIG. 2, bending displacement occurs in the X-axis direction. Accordingly, the cantilever beam 2 bends and vibrates at the resonance frequency in the horizontal direction, that is, the X-axis direction in the drawing by such driving.

The X-direction vibration of the cantilever 2 causes the electrodes 7a, 6
The capacitances Cma and Cmb between the electrodes 7b and 6 are X
The phases change in opposite phases according to the vibration displacement ΔX in the direction. Such changes in the capacitances Cma and Cmb are detected by the respective capacitance / voltage conversion circuits 52a and 52b by the minute detection current supplied from the power supply circuit 51 to the respective capacitances, and the respective voltages Vm and Vm are detected.
a, Vmb.

In this state, when the angular velocity Ω acts around the axis G of the cantilever 2, that is, the Z-axis in the figure, the vibrating piece is applied to the cantilever 2 as its equivalent mass m in the Y-axis direction in the figure. The Coriolis force Fc of Fc = 2 mΩ × Vx acts as the velocity Vx in the X direction. Due to this Coriolis force Fc, the cantilever 2
Vibrates in the Y direction depending on the rigidity of the support piece 3 in the Y-axis direction, and the displacement ΔD of the distance between the detection electrodes due to the vibration depends on the angular velocity Ω.

When the cantilever 2 vibrates and displaces in the Y-axis direction, the capacitances Cma and Cmb change in phase due to the vibrational displacement ΔD, and the sum of the capacitances ΔCm becomes the displacement ΔD as shown in the above equation.
That is, it depends on the angular velocity Ω. Therefore, the sum of capacitance ΣCm
The voltage ΔVm (= Vma + Vmb) corresponding to the following equation is obtained by the adder circuit 53, detection is performed by the detection circuit 56 based on the signal from the drive circuit 50, and amplification is performed by the output adjustment circuit 57 so as to have an appropriate output range. Output as angular velocity signal VΩ.

On the other hand, the voltages Vma and Vmb are
5 to obtain ΔVm (= Vma−Vmb). Further, the dividing circuit 58 calculates the capacitance ratio R shown in the above equation.
Is obtained by ΔVm / ΣVm.

The drive control circuit 54 performs feedback control of the drive circuit 50 so that the output R of the division circuit 58, that is, the differential value of the vibration amplitude ΔX in the X direction becomes a predetermined constant value, and the cantilever 2
The X-direction vibration velocity v _X corresponding to the above equation is always a constant value v
Control to be _C. Here, the feedback signal R for controlling the drive speed v _X does not depend on ΔD from the above equation, and is not affected by the Coriolis force Fc.

In this embodiment, the cantilever 2 is flexurally vibrated by the expansion and contraction of the piezoelectric element 4B, and the driving voltage with respect to the driving amplitude can be smaller than that in the conventional electrostatic driving. There is an advantage that the detection sensitivity / drive voltage ratio is large. Further, since there is no component of the driving force Fd superimposed on the Coriolis force Fc at the time of vibration in the Y-axis direction, the angular velocity Ω
Can be accurately detected.

Embodiment 21 FIG. 35 and 36 show another embodiment of the present invention. FIG. 35 is a plan view of a cantilever detecting section of the angular velocity sensor in this embodiment, and FIG. 36 is a block diagram of an angular velocity detecting circuit.

In FIG. 35, reference numeral 7 denotes one large detection electrode on one side provided on the upper surface of the Si substrate 1, and 6 denotes the cantilever 2
Is a detection electrode on the other side provided to face the detection electrode 7 on the lower surface on the front side of the sensor. Here, the area of the detection electrode 7 is larger than that of the detection electrode 6 so that the area facing the detection electrode 6 does not change with respect to the horizontal vibration of the cantilever 2.

Therefore, the capacitance Cm between the detection electrodes 7 and 6 is
Changes only with respect to the inter-electrode distance D, and assuming a displacement ΔD in the Y direction from the stationary position D0, the facing area S between the electrodes and the dielectric constant ε of the medium are Cm = εS / (D0 ± ΔD). .

In FIG. 36, 52 is a capacitance / voltage conversion circuit connected to the detection electrode 7, 59a is a first current / voltage conversion circuit connected to the electrode 47a, and 59b is an electrode 45b
Is connected to the output of the current / voltage conversion circuits 59a and 59b.

The drive control circuit 54 has an addition circuit 53
And the drive voltage V of the drive circuit 50 are connected, and the output of the capacitance / voltage conversion circuit 52 is connected to the detection circuit 56, and the signal of the drive circuit 50 is connected as a control signal as in the twentieth embodiment. I have. Also, the piezoelectric element 4
B has been subjected to the same polarization treatment as in the twentieth embodiment.

In FIG. 36, first, the drive circuit 50 is connected between the electrodes 45a and 47a and the electrode 45 as in the twentieth embodiment.
An alternating voltage of opposite phase is applied between b and 47b to bend the piezoelectric element 4B in the X-axis direction and to cause the cantilever 2 to bend and vibrate in the X-axis direction at its resonance frequency. Electrodes 45a, 4 of piezoelectric element 4B
7a and the current Ia flowing between the electrodes 45b and 47b,
The current Ib is detected by the current / voltage conversion circuits 59a and 59b and converted into a voltage, and a voltage corresponding to I = Ia + Ib is calculated by the addition circuit 53.

This voltage corresponds to the total current flowing through the piezoelectric element 4B. Here, if the oscillation speed of the X-axis direction of the piezoelectric element 4B v _X, the force factor A, the braking admittance and Yd, a piezoelectric basic equations, the _{v X = (I-Yd ×} V) / A.

Therefore, the drive control circuit 54 includes an adder circuit 53
From the total current I, which is the output of the driving circuit 50, and the driving voltage V, which is the output of the driving circuit 50, the constants Yd, A which are unique to the piezoelectric element 4B.
Using, determine the vibration velocity v _X the above equation, and controls the driving voltage V so that they match by comparing it with a predetermined value v _X0. Such control, X-axis direction vibration velocity v _X the cantilever 2 is always kept constant.

In this state, when an angular velocity Ω acts around the Z-axis of the cantilever 2, the cantilever 2 depends on the rigidity of the support piece 3 in the Y-axis direction due to the Coriolis force Fc generated in the Y-direction. The displacement ΔD of the distance between the detection electrodes due to the vibration depends on the angular velocity Ω.

A change in the capacitance Cm of the detection capacitance portion of the cantilever 2 due to the vibration displacement ΔD is obtained by converting the capacitance Cm into a voltage Vm by the capacitance / voltage conversion circuit 52 and a signal from the drive circuit 50 by the detection circuit 56. After the detection is performed based on the above, amplification is performed by the output adjustment circuit 57 so as to be in an appropriate output range, and the result is output as the angular velocity signal VΩ.

In this embodiment, the same effects as those of the twentieth embodiment can be obtained, and the division circuit is not required. Therefore, the circuit is simplified and the cost is reduced, and the number of electrodes of the detection capacitance unit is reduced. Therefore, there is also an advantage that the number of lead wires is reduced and a mask pattern at the time of electrode formation such as lead routing can be simplified.

In the above embodiment, the drive voltage V is controlled by detecting the drive voltage V and the current I of the piezoelectric element 4B. However, the drive current I may be controlled or the drive voltage V may be kept constant. The driving current I may be controlled as a voltage, or the voltage V may be controlled using the driving current I as a constant current.

Embodiment 22 FIG. FIG. 37 is a plan view showing an embodiment in which the vibrating piece is a doubly-supported beam. Reference numeral 23A denotes a plate-like doubly-supported beam serving as a support piece disposed in parallel and close proximity to the Si substrate 1, and a piezoelectric element 4B is laminated on the upper surface. As a whole, an elongated columnar beam is formed, and 32A is provided at both ends of the doubly supported beam 23A and the fixed portion 3A.
2a, and is provided on an extension of the doubly supported beam 23A,
This support piece has a bending elastic modulus in the vertical direction with respect to the Si substrate 1 smaller than that in the horizontal direction with respect to the Si substrate 1.

The detection electrode 6 is located at the center of the doubly supported beam 23A.
The detection electrode 7 is located on the i-substrate 1 at a position facing the detection electrode 7.
It has a smaller area and is symmetrically arranged on a vertical plane of the axis G of the doubly supported beam 23A.

Such an angular velocity sensor can be manufactured in the same manufacturing process as the method described with reference to FIG.
Is similarly detected using the detection circuit of FIG. This embodiment has the same effect as that of the twenty-first embodiment, and is advantageous in mechanical strength against impact.

Embodiment 23 FIG. FIG. 38 shows the supporting piece as the vibrating piece 2A.
FIG. 21 is a plan view showing an embodiment provided in the middle, 21 is a plate-shaped cantilever base arranged close to and parallel to the Si substrate 1, a piezoelectric element 4 </ b> B is laminated on the upper surface, and an elongated columnar beam is formed as the whole base. 22 is a plate-shaped cantilever tip having a high bending rigidity, which is similarly disposed close to and in parallel with the Si substrate 1, and 31 is a bending elasticity which connects the cantilever base 21 and the cantilever tip 22 in the vertical direction. It is a support piece which has.

Here, the detection electrode 6 faces the detection electrode 7 on the Si substrate 1 on the lower surface of the cantilever tip portion 22,
It is arranged symmetrically with respect to the extension axis of the cantilever base 21 in a smaller area.

In such a configuration, the piezoelectric element 4B is driven to cause the cantilever base 21 to bend and vibrate in the X-axis direction, and the cantilever tip 22 is similarly vibrated in the X-axis direction in conjunction with this. When the angular velocity Ω acts around the axis of the cantilever 2A in this state, the cantilever tip 22 is displaced and vibrated by the Coriolis force in the Y-axis direction due to the Y-axis bending elasticity of the support piece 31, so that the electrodes 7, 6 The capacitance Cm between them changes.

Therefore, using the detection circuit shown in FIG.
The angular velocity Ω can be detected from the change in the capacitance Cm. In this embodiment, since the cantilever base 21 does not vibrate in the Y-axis direction, vibration modes can be separated, and there is an advantage that the degree of freedom in dimensional design of the beam is increased.

Embodiment 24 FIG. In each of the above embodiments, the case where the electrodes 45a and 47a and the electrodes 45b and 47b of the piezoelectric element 4B are all independent has been described. However, some of the electrodes can be shared depending on the polarization direction and the driving method of the piezoelectric element 4B.

FIG. 39 is a partial block diagram of a detection circuit for explaining an embodiment in which the electrodes of the piezoelectric element 4B are used in common. The electrodes 45a and 45b on the lower surface of the piezoelectric element 4B are used as common electrodes 45A.

Here, the common electrode 45A is connected to the drive circuit 50,
The electrode 47a is connected to the current / voltage conversion circuit 59a by the electrode 47b.
Are connected to the current / voltage conversion circuit 59b. Otherwise, the same detection circuit as in FIG. 36 is used. Piezoelectric element 4B
A reverse DC electric field is applied between the electrodes 47a and 45A and the electrodes 47b and 45A in advance, and the polarization polarities of the regions of the piezoelectric film 46 sandwiched between the electrodes 47b and 45A and between the electrodes 47b and 45A are opposite to each other. The polarization process is performed so that

The drive circuit 50 supplies the common electrode 45
When an alternating voltage is applied between A and the electrodes 47a and 47b, for example, the common electrode 45A and the electrode 47b
In the case where the region between them extends in the Z-axis direction, the common electrode 45A
Since the area between the electrode 47a and the electrode 47a contracts in the opposite direction, the tip of the cantilever 2 is bent in the X-axis direction in the figure, and as a result, the cantilever 2
Vibrates flexibly in the horizontal direction. During bending vibration, each electrode 41
The current flowing between the electrodes 43a and 43b is detected by the current / voltage conversion circuits 59a and 59b, the total current I is obtained by the addition circuit 53, and the angular velocity .OMEGA.
The change in the capacitance Cm is detected using the circuit shown in FIG.

According to this embodiment, since the electrodes of the piezoelectric element 4B can be shared, there is an advantage that the number of electrodes of the piezoelectric element 4B can be reduced.

In the above embodiment, the electrodes 47a, 47
b is shown separately, but since the current flows by shunting the respective polarization regions of the piezoelectric film 46, the electrode 4 is used in a detection circuit as shown in FIG.
7a and 47b may be shared, and in this case, the addition circuit 53 becomes unnecessary. Also, in the embodiment shown in FIG. 34 in which the left and right polarizations of the piezoelectric element 4B are aligned, the electrodes 43a and 43b are made common electrodes and grounded, and the electrodes 45a and
Even if an alternating voltage of the opposite phase is applied to 45b, the electrodes can be shared.

Embodiment 25 FIG. FIG. 40 is a cross-sectional view of a detection unit showing an embodiment having a pair of piezoelectric elements. In this embodiment, instead of the above-described piezoelectric element 4B, the cantilever 2 is perpendicular to the axis G on the cantilever 2. A pair of piezoelectric elements 4 symmetrical to the plane
C and 4D are provided. The piezoelectric elements 4C and 4D are in the same direction, that is, between the electrodes 47a and 45a and the electrodes 47b and 45
b) Polarize by applying a DC electric field in the same direction between b, and drive by applying an alternating voltage of opposite phase between both electrodes during driving, or polarize by applying a DC electric field in the opposite direction between both electrodes. In addition, the driving is performed by applying an in-phase alternating voltage between both electrodes at the time of driving.

In the former case where the electrodes 45a and 45b are on the ground side, and in the latter case the electrodes 45a and 45b
It is preferable that b is formed as a common electrode. In this embodiment, since there is no neutral region in the piezoelectric films 46a and 46b, the electromechanical conversion efficiency per area of the piezoelectric element can be increased, and the horizontal rigidity of the beam can be reduced. However, there is an advantage that a larger vibration displacement in the horizontal direction can be obtained, and the detection sensitivity is improved.

Embodiment 26 FIG. FIG. 41 is a plan view showing an embodiment in which a penetrating portion is provided along the axis G of the cantilever 2.
Is an elongated penetrating portion vertically penetrating the cantilever 2 along the axis G at the center of the cantilever 2. Piezoelectric elements 4E and 4F are formed on both sides of the penetrating portion 81 on the upper surface of the cantilever 2, and detection electrodes 6a and 6b are formed on the lower surface. Detection electrodes 6a, 6b
32, a connection pattern may be arranged and maintained at the same potential depending on the detection method, or the detection electrodes 7 on the other side may be made smaller than the electrodes 6a and 6b so that the arrangement of the detection electrodes is opposite to that shown in FIG. You may do it. The penetrating portion 81 is provided in the cantilever 2 in the manufacturing process diagrams (C) to (D) of the detecting portion shown in FIG.
The SiO ₂ film 12 forming the lower layer of the skeleton, the poly-Si layer 13 serving as the central layer, and the mask used for manufacturing the SiO ₂ film 12 forming the upper layer of the skeleton are changed.

Although not shown, first, the SiO ₂ film 12 is laminated on the portion excluding the penetrating portion 81, and then, outside the wall and inside, ie, the inside of the penetrating portion 81, except for a region which becomes a wall around the penetrating portion 81. The SiO ₂ film 12 is again stacked on the portion excluding the through portion 81 from above, and the wall is filled with the SiO ₂ film 12 to separate the poly Si layer 13 inside the through portion. Then, in the step (G), the poly-Si layer 13 inside the penetrating portion 81 continuous with the poly-Si layer 11 is simultaneously selectively etched, so that the gap 18 and the penetrating portion 81 are simultaneously formed.
To form

According to this embodiment, since the effective rigidity of the cantilever 2 in the horizontal direction can be reduced by the penetrating portion 81, there is an advantage that the detection sensitivity can be further improved.

In the above-described embodiment, an example in which the penetrating portion 81 is provided along the axis G of the cantilever 2 is shown. However, the same effect can be obtained by providing the penetrating portion 81 along the axis G of the doubly supported beam 23A. Needless to say, can be expected.

Embodiment 27 FIG. FIG. 42 is a plan view showing an embodiment in which a plurality of penetrating portions are provided in the cantilever. As in the twenty-sixth embodiment, an elongated penetrating portion 81 is provided along the central axis G of the cantilever 2 and the cantilever is provided. Another penetrating portion 82 is provided at the base of the holding portion 3 a of the beam 2, and the base of the cantilever 2 is divided into two elongated columnar portions 83.
a and 83b, and the supporting pieces of the cantilever 2 are formed by the elongated columnar portions 22a and 22.

According to this embodiment, the same advantages as those of the twenty-sixth embodiment can be obtained. In addition, by forming the supporting pieces of the cantilever 2 on both sides of the beam, the cantilever around the Z axis at the time of driving in the X axis direction can be obtained. There is also an advantage that the torsion of the beam 2 can be reduced.

In the above embodiment, the penetrating portions 81 and 82 are provided apart from each other. However, the penetrating portions 81 and 82 may be continuous penetrating portions.

[0287]

As described above, according to the first aspect of the present invention, the area provided on the vibrating reed and the substrate facing the vibrating reed has an invariable overlapping area with respect to the horizontal vibration of the vibrating reed. Since a pair of drive electrodes and at least two pairs of detection electrodes whose areas overlapping each other with respect to the horizontal vibration of the vibrating piece change mutually are provided, high detection sensitivity is obtained even at a low drive voltage. In addition to this, an angular velocity detection error due to driving can be suppressed, and an effect that this can be realized with a simple and small structure is obtained.

According to the second aspect of the present invention, there is provided a holding portion fixed to the substrate, and other than the holding portion, the holding portion is disposed close to and opposed to the substrate, and is bent in the horizontal direction with respect to the substrate surface halfway. A cantilever beam having a supporting piece to be bent and deformed in a direction perpendicular to the substrate surface on the holding portion side from the supporting piece, and the cantilever beam on the holding portion side and the substrate at a position facing the cantilever beam, respectively. The pair of drive electrodes provided are provided on the cantilever beam on the tip end side of the support piece and on the substrate at a position facing the cantilever beam, and overlap with each other for horizontal vibration on the tip end side. Since at least two pairs of detection electrodes having variable areas are provided, the vibration in the horizontal direction of the base of the cantilever is suppressed, and the vibration mode can be separated from the tip of the cantilever. Increase design flexibility It is effective to obtain what may.

According to the third aspect of the present invention, since the detection electrode is arranged on the tip side of the vibrating reed or the cantilever with respect to the drive electrode, the displacement of the detection electrode in the X-axis direction is increased. In addition, there is an effect that a device capable of further improving the angular velocity detection sensitivity is obtained.

According to the fourth aspect of the present invention, two pairs of drive detection electrodes are provided between the vibrating reed and the substrate facing the vibrating reed so that the areas overlapping each other with respect to the horizontal vibration of the vibrating reed vary. With such a configuration, there is an effect that even if the number of electrodes is reduced, it is possible to obtain a device that can facilitate wiring, simplify masking when forming electrodes, and reduce stray capacitance between leads.

According to the fifth aspect of the present invention, the vibrating piece is a cantilever, and the supporting piece is provided at one end or in the middle of the cantilever in the axial direction of the cantilever. The elastic support of the cantilever has an effect that a displacement can be detected by the detection electrode with high sensitivity.

According to the sixth aspect of the present invention, the vibrating piece is a doubly supported beam, and the supporting piece is provided at both ends of the doubly supported beam in the axial direction thereof, and the drive electrode and the detection electrode or the drive detection electrode are provided at the both ends. Since the beams are arranged symmetrically with respect to the center vertical plane in the width direction of the cantilever, there is an effect that a mechanical strength against impact can be increased.

According to the seventh aspect of the present invention, any one of the plurality of detection electrodes formed on the vibrating reed, the cantilever beam, or the cantilever beam, and the plurality of detection electrodes formed on the substrate side corresponding to these are provided. Is configured as a common detection electrode, so that the number of leads passing through the support piece can be reduced, wiring can be simplified, masking at the time of electrode formation can be simplified, and stray capacitance between the leads can be reduced. There is an effect that what can be obtained is obtained.

According to the eighth aspect of the present invention, there is provided a holding portion fixed to the substrate, and other than the holding portion, the holding portion is disposed so as to face the substrate, and is bent and deformed in a direction perpendicular to the substrate surface. A rectangular vibrating reed, a supporting piece provided at each corner of the rectangular vibrating reed and being bent and deformed in the horizontal direction with respect to the substrate surface, and a rectangular vibrating reed and provided on the substrate opposed thereto, respectively. A driving electrode having an invariable overlapping area with the horizontal vibration of the rectangular vibrating piece and a two horizontal electrode having a mutually overlapping area of the rectangular vibrating piece overlapping with the horizontal vibration. Since the configuration is such that four pairs of detection electrodes are provided in the axial direction, an effect is obtained in which an angular velocity of two axes around the horizontal axis can be simultaneously detected.

According to the ninth aspect of the present invention, the four drive detecting electrodes which are symmetrical with respect to the center axis of the rectangular vibrating piece change in area where the rectangular vibrating piece overlaps with the horizontal vibration. Is provided, so that the angular velocity of the two axes around the horizontal axis can be simultaneously detected and the number of electrodes can be reduced.

According to the tenth aspect of the present invention, at least one of the drive electrode and the detection electrode formed on the vibrating reed or the doubly supported beam, and the drive electrode and the detection electrode formed on the substrate side corresponding thereto. Are used as common electrodes, so that there is an effect that the number of leads can be reduced, wiring and masking can be simplified, and stray capacitance between the leads can be reduced.

According to the eleventh aspect of the present invention, the weight for adjusting the resonance frequency is provided on a part of the upper surface of the resonator element, so that the resonance frequency determined by the shape of the resonator element can be appropriately adjusted. Has the effect.

According to the twelfth aspect of the present invention, a pair of drive electrodes provided on the vibrating reed and the substrate surface opposed to the vibrating reed, respectively, and having a constant overlapping area with respect to the horizontal vibration of the vibrating reed, Providing at least two pairs of detection electrodes whose areas overlapping each other with respect to the horizontal vibration of the vibrating reed are mutually changed, and wherein the vibrating reed is vibrated in the vertical direction near a resonance frequency; Since the angular velocity around the axis of the vibrating reed is detected by the angular velocity detection circuit from the frequency component of the capacitance difference between the detection electrodes, the detection sensitivity can be increased even at a low driving voltage, and the driving speed can be increased. There is an effect that an angular velocity detection error can be suppressed and an angular velocity calculation can be easily realized by simple signal processing.

According to the thirteenth aspect of the present invention, there is provided a holding portion fixed to the substrate, and other than the holding portion, the holding portion is disposed close to and opposed to the substrate, and is bent and deformed in the horizontal direction with respect to the substrate surface. A cantilever having a support piece in the middle and being bent and deformed mainly in a direction perpendicular to the substrate surface on the holding portion side with respect to the support piece, the base of the cantilever on the holding portion side and a position facing the base A pair of drive electrodes respectively provided on the substrate, and the cantilever beam on the distal end side of the support piece and the substrate on the substrate at a position facing the cantilever beam, and the horizontal vibration on the distal end side is provided. And at least two pairs of detection electrodes whose mutually overlapping areas are mutually changed are provided, and the frequency of the capacitance difference between the detection electrodes when the cantilever is vibrated near the resonance frequency in the vertical direction. Component to the angular velocity detection circuit The structure is designed to detect the angular velocity of the cantilever around the axis, so that the horizontal vibration of the base of the cantilever is suppressed, the vibration mode can be separated from the tip of the cantilever, and the dimensional design of the cantilever The degree of freedom can be increased, and this has the effect of obtaining an angular velocity calculation with high accuracy by simple signal processing.

According to the fourteenth aspect of the invention, the vibrating reed and the substrate facing the vibrating reed are provided with two pairs of drive detection electrodes whose overlapping areas change with respect to the horizontal vibration of the vibrating reed. When the pair of drive detection electrodes are driven in phase to vibrate the vibrating reed vertically in the vicinity of the resonance frequency, the angular velocity detection circuit obtains the vibration based on the frequency component of the capacitance difference between the two pairs of drive detection electrodes. Since the angular velocity around the axis of one piece is detected, it is possible to simplify wiring even if the number of electrodes is reduced, simplify masking when forming electrodes, and reduce stray capacitance between leads. There is an effect that the angular velocity can be detected with high accuracy by signal processing.

According to the fifteenth aspect of the present invention, there is provided a rectangular shape having a holding portion fixed to the substrate, other than the holding portion, disposed close to and opposed to the substrate, and bent and deformed in a direction perpendicular to the substrate surface. A vibrating piece, a supporting piece provided at each corner of the rectangular vibrating piece and being bent and deformed in a horizontal direction with respect to the substrate surface, and a supporting piece provided on the rectangular vibrating piece and the substrate opposed thereto. A driving electrode having an invariable overlapping area with the horizontal vibration of the rectangular vibrating piece and a two horizontal electrode having a mutually overlapping area of the rectangular vibrating piece overlapping with the horizontal vibration. Four pairs of detection electrodes in the axial direction are provided, and the angular velocity detection circuit detects an angular velocity of each of the rectangular vibrating reeds around each horizontal axis from the frequency component of the capacitance difference between the pair of detection electrodes. Because it was configured, around the horizontal axis Can detect the axis of the angular velocity at the same time,
There is an effect that a device that can realize this with high precision by signal processing is obtained.

According to the sixteenth aspect of the present invention, four pairs of drive detections whose points overlap with each other with respect to the center axis of the rectangular vibrating piece change in the area where the rectangular vibrating piece overlaps with the horizontal vibration. Electrodes are provided, and the drive detection electrodes are driven in phase to oscillate the rectangular vibrating reed vertically in the vicinity of the resonance frequency, thereby reducing the sum of the capacitances between the two pairs of drive detection electrodes in the horizontal axis direction by one. From the above frequency component of the capacitance difference between each set,
Since the angular velocity detecting circuit is configured to detect the angular velocity of each of the rectangular vibrating pieces around each horizontal axis, the angular velocity detecting circuit detects the angular velocity around the horizontal axis.
In addition to being able to simultaneously detect the angular velocities of the shafts, there is an effect that the angular velocities can be detected with high accuracy by signal processing.

According to the seventeenth aspect of the present invention, there is provided a holding portion fixed to the substrate, and other than the holding portion, the holding portion is disposed so as to face one surface of the substrate, and is at least partially provided with respect to the substrate surface. A vibrating reed that bends and deforms mainly in a vertical direction, a supporting piece that is provided continuously to a part of the vibrating reed and that bends and deforms in a horizontal direction with respect to the substrate surface, and a piezoelectric element provided on one surface of the vibrating reed. Formed on the vibrating reed and the substrate,
Since at least two pairs of detection electrodes whose overlapping areas change with respect to the horizontal vibration of the resonator element are provided, the detection sensitivity can be increased even with a low driving voltage, and the angular velocity detection error due to driving can be improved. There is an effect that a product that can suppress the occurrence of the problem can be obtained.

According to the eighteenth aspect of the present invention, the supporting piece is provided on the cantilever support side of the vibrating piece, and the detecting electrode is provided on the free end side of the vibrating piece. There is an effect that a device that can detect a change in capacitance with high sensitivity can be obtained.

According to the nineteenth aspect, the supporting piece is provided on the both-side supporting side of the vibrating piece, and the detecting electrode is provided symmetrically with respect to the center vertical plane in the width direction of the vibrating piece. There is an effect that a material that can increase the mechanical strength of the piece is obtained.

According to the twentieth aspect of the present invention, a supporting piece is provided in the middle of the vibrating piece, a piezoelectric element is provided on the vibrating piece on the holding portion side with respect to the supporting piece, and a detection electrode is provided on a tip side with respect to the supporting piece. Since the vibrating reed is configured so as to be symmetrical with respect to the center vertical plane in the width direction, vibration in the horizontal (X-axis) direction of the cantilever base can be suppressed, and the vibration mode can be separated. There is an effect that a beam that can increase the degree of freedom in dimensional design of the cantilever is obtained.

According to the twenty-first aspect of the present invention, a horizontally deforming supporting piece provided at each corner of a rectangular vibrating piece, and extending and contracting in a peripheral direction from a center thereof provided on one surface of the rectangular vibrating piece. Since the piezoelectric element polarized so as to be displaced and the four pairs of detection electrodes whose overlapping area changes in each horizontal direction with respect to each horizontal vibration of the rectangular vibrating piece are provided, a horizontal axis is provided. There is an effect that an angular velocity of two surrounding axes can be detected at the same time.

According to the twenty-second aspect of the present invention, four pairs of detection electrodes which are point-symmetric with respect to the center axis of the rectangular vibrating reed, whose overlapping areas change with respect to the vibration of the rectangular vibrating reed in the horizontal axis direction. , So that 2 around the horizontal axis
In addition to being able to detect the angular velocity of the shaft at the same time, there is an effect that an S / N ratio can be improved by increasing the electrode area.

According to the twenty-third aspect of the present invention, since the weight for adjusting the resonance frequency is provided in a part of the resonator element, the resonance frequency determined by the shape of the resonator element can be appropriately adjusted. There is.

According to the twenty-fourth aspect of the present invention, since a plurality of detection electrodes formed on a cantilever beam, a doubly supported beam, or a rectangular vibrating piece are configured as a common electrode, the detection electrodes can be made common by using a common electrode. There is an effect that a mask pattern of the detection electrode can be simplified and the number of lead lines can be reduced.

According to the twenty-fifth aspect of the invention, at least two pairs of detection electrodes are provided, the areas of which overlap with each other with respect to the horizontal vibration of the vibrating reed. When the piece is vibrated in the vicinity of the resonance frequency in the vertical direction, the angular velocity detection circuit is configured to calculate the angular velocity of the vibrating piece around the axis from the frequency component of the capacitance difference between the detection electrodes. In addition, the angular velocity can be accurately detected, the detection sensitivity can be increased even with a low drive voltage, and the angular velocity detection error can be suppressed.

According to the twenty-sixth aspect of the present invention, a horizontally deforming supporting piece provided at each corner of the rectangular vibrating piece, and extending and contracting in a peripheral direction from a center of the supporting piece provided on one surface of the rectangular vibrating piece. A piezoelectric element polarized so as to be displaced, and four pairs of detection electrodes whose areas overlapping each other in the horizontal direction change with respect to each horizontal vibration of the rectangular vibrating piece are provided, and the piezoelectric element is driven by driving the piezoelectric element. When the rectangular vibrating piece is vibrated in the vertical direction in the vicinity of the resonance frequency, the frequency component of the capacitance difference between each pair of detection electrodes is configured to be calculated by an angular velocity detection circuit. This has an effect that an angular velocity of two axes around the horizontal axis can be detected simultaneously and with high accuracy.

According to the twenty-seventh aspect, four pairs of detection electrodes which are point-symmetric with respect to the center axis of the rectangular vibrating reed, wherein the areas overlapping each other with respect to the vibration of the rectangular vibrating reed in the horizontal axis direction change. And a set of the sum of the capacitances between the two pairs of detection electrodes in each horizontal axis direction when the piezoelectric element is driven to vibrate the rectangular vibrating piece in the vertical direction near the resonance frequency. Since the angular velocity detecting circuit is configured to detect the angular velocity of each of the rectangular vibrating pieces around each horizontal axis from the above-mentioned frequency component of the capacitance difference, it is possible to obtain an apparatus that can simultaneously detect the angular velocities of two axes around the horizontal axis. effective.

According to the twenty-eighth aspect of the present invention, an elongated vibrating reed is provided symmetrically on one surface of the vibrating reed in a direction perpendicular to the axial center of the vibrating reed, and laminated so as to sandwich the piezoelectric film between two pairs of upper and lower electrodes. Providing a piezoelectric element polarized so as to expand and contract the vibrating piece in the horizontal direction, the vibrating piece and the substrate,
Since the two pairs of detection electrodes are formed so that the overlapping area changes with respect to the horizontal vibration of the vibrating piece, the ratio of the angular velocity detection sensitivity / drive voltage is increased by using an elongated diaphragm. There is an effect that a device that can realize accurate angular velocity detection is obtained.

According to the twenty-ninth aspect of the present invention, a pair of detection electrodes having an invariable facing area with respect to the horizontal vibration of the vibrating bar are formed on the vibrating bar and the substrate, respectively. This has the effect of simplifying the processing, reducing the number of electrodes, and achieving a mask pattern that can be simplified.

According to the thirtieth aspect of the present invention, the piezoelectric element 2
Since at least one electrode of the piezoelectric element among the pair of electrodes is configured to be common, an effect is obtained in which the number of electrodes of the piezoelectric element can be reduced and the connection circuit can be simplified.

[0317] According to the thirty-first aspect, the piezoelectric element is
Each piezoelectric film is laminated so as to be sandwiched between each pair of electrodes, and is arranged symmetrically with respect to the center vertical plane in the width direction of the resonator element. There is an effect that an electromechanical conversion efficiency per area of the piezoelectric element can be increased and a detection sensitivity can be improved without forming a conductive region.

According to the thirty-second aspect, the vibrating reed is a cantilever, the support piece is provided on the cantilever support side of the vibrating reed, and the detection electrode is provided on the free end side of the vibrating reed. Therefore, there is an effect that a device capable of detecting the amount of change in capacitance between the detection electrodes with high sensitivity can be obtained.

According to the thirty-third aspect of the present invention, the vibrating reed is a doubly supported beam, the supporting piece is provided on the doubly supported side of the vibrating reed, and the detection electrode is symmetrical with respect to a center vertical plane in the width direction of the vibrating reed. , It is possible to obtain a device that can increase the mechanical support strength of the resonator element.

According to the thirty-fourth aspect of the present invention, the vibrating piece is a cantilever, and the supporting piece is provided in the middle of the vibrating piece.
Has bending elasticity in the vertical direction,
Since the displacement is smaller on the holding part side than the tip part side , the piezoelectric element is provided on the holding part side, and the detection electrode is provided on the tip part side, the base of the vibrating piece vibrates in the vertical direction. By suppressing the vibration mode, it is possible to separate the vibration modes, thereby providing an effect of obtaining a high degree of freedom in dimensional design as a cantilever.

According to the thirty-fifth aspect of the present invention, since a penetrating portion is provided in a part of the vibrating reed along the center vertical plane in the width direction of the vibrating reed, the vibrating reed as a cantilever is provided. By reducing the substantial rigidity in the horizontal direction, there is an effect that a detection sensitivity can be significantly improved.

According to the thirty-sixth aspect of the present invention, two pairs of detection electrodes whose areas overlapping each other change with respect to horizontal vibration of the vibrating piece are provided, and a piezoelectric element is driven in the angular velocity detecting circuit to drive the vibrating piece. When the piezoelectric element is configured to detect the angular velocity about the axis of the vibrating reed from the frequency component of the capacitance sum between the detection electrodes of each pair when bending vibration is performed in the vicinity of the resonance frequency in the horizontal direction. The vertical vibration of the vibrating reed caused by the vibration is obtained by the change in the sum of capacitance due to the vertical displacement of each pair of detection electrodes, and the angular velocity about the center axis in the width direction of the vibrating reed is obtained from the frequency component of the change in the sum of capacitance. There is an effect that what can be obtained is obtained.

According to the thirty-seventh aspect of the present invention, a pair of detection electrodes having a constant facing area with respect to the horizontal vibration of the vibrating reed is provided, and the piezoelectric element is driven in the angular velocity detecting circuit to move the vibrating reed horizontally. Since the frequency component of the capacitance between the detection electrodes when the bending vibration is performed in the vicinity of the resonance frequency in the direction, the angular velocity around the axis of the resonator element is configured to be detected.
With only one pair of detection electrodes, an effect is obtained in which an angular velocity around the central axis in the width direction of the resonator element can be obtained.

According to the thirty-eighth aspect of the present invention, the piezoelectric element is controlled by controlling the driving voltage or the driving current in the angular velocity detecting circuit so that the ratio of the capacitance difference to the sum of the capacitances of each pair of detecting electrodes is constant. Since it is configured to be driven at a predetermined vibration speed, it is possible to maintain the vibration speed of the bending vibration in the driving direction of the vibrating piece at a predetermined value from the ratio of the capacitance sum and the capacitance difference between the pair of detection electrodes. There is an effect that can be obtained.

According to the thirty-ninth aspect, the difference between the current applied to the piezoelectric element and the product of the voltage applied to the piezoelectric element and the braking admittance of the piezoelectric element is equal to the predetermined value. The piezoelectric element is driven at a predetermined vibration speed by controlling the voltage or the current so that the vibration admittance of the piezoelectric element and the voltage and current applied to the piezoelectric element are used. There is an effect that a vibration velocity in the driving direction of the piece can be maintained at a predetermined value.

[Brief description of the drawings]

FIG. 1 is a plan view showing an angular velocity sensor used in an angular velocity detecting device according to one embodiment of the present invention.

FIG. 2 shows the angular velocity sensor in FIG. 1 in detail A-
FIG. 3 is a sectional view taken along line A.

FIG. 3 shows the angular velocity sensor in FIG. 1 in detail B-
It is a B sectional view.

FIG. 4 is a process chart showing a manufacturing procedure of the angular velocity sensor in FIG. 1;

FIG. 5 is a block diagram showing an angular velocity detection circuit in the angular velocity detection device of the present invention.

FIG. 6 is a plan view showing another embodiment of the angular velocity sensor according to the present invention.

FIG. 7 is a plan view showing another embodiment of the angular velocity sensor according to the present invention.

FIG. 8 is a plan view showing still another embodiment of the angular velocity sensor according to the present invention.

FIG. 9 is a plan view showing another embodiment of the angular velocity sensor according to the present invention.

FIG. 10 is a plan view showing still another embodiment of the angular velocity sensor according to the present invention.

FIG. 11 is a plan view showing still another embodiment of the angular velocity sensor according to the present invention.

FIG. 12 is a plan view showing another embodiment of the angular velocity sensor according to the present invention.

FIG. 13 is a plan view showing still another embodiment of the angular velocity sensor according to the present invention.

FIG. 14 is a block diagram showing an angular velocity detection circuit used in the angular velocity sensor of FIG.

FIG. 15 is a plan view showing another embodiment of the angular velocity sensor according to the present invention.

FIG. 16 is a plan view showing another embodiment of the angular velocity sensor according to the present invention.

FIG. 17 is a plan view showing still another embodiment of the angular velocity sensor according to the present invention.

18 is a block diagram showing an angular velocity detection circuit used in the angular velocity sensor shown in FIG.

FIG. 19 is a plan view showing another embodiment of the angular velocity sensor according to the present invention.

FIG. 20 is a sectional view taken along line CC of the angular velocity sensor in FIG. 19 in detail.

FIG. 21 is a plan view showing an angular velocity sensor used in an angular velocity detecting device according to another embodiment of the present invention.

FIG. 22 is a sectional view taken along line DD of the angular velocity sensor in FIG. 21 in detail.

FIG. 23 is a process chart showing a manufacturing procedure of the angular velocity sensor in FIG. 21;

FIG. 24 is a block diagram showing an angular velocity detection circuit in the angular velocity detection device of the present invention.

FIG. 25 is a plan view showing another embodiment of the angular velocity sensor according to the present invention.

FIG. 26 is a plan view showing still another embodiment of the angular velocity sensor according to the present invention.

FIG. 27 is a plan view showing another embodiment of the angular velocity sensor according to the present invention.

FIG. 28 is a plan view showing another embodiment of the angular velocity sensor according to the present invention.

FIG. 29 is a block diagram showing an angular velocity detection circuit used for the angular velocity sensor in FIG. 28;

FIG. 30 is a longitudinal sectional view showing still another embodiment of the angular velocity sensor according to the present invention.

FIG. 31 is a plan view showing an angular velocity sensor according to another embodiment of the present invention.

32 is a sectional view taken along line EE of the angular velocity sensor in FIG. 31 in detail.

FIG. 33 is a process chart showing a manufacturing procedure of the angular velocity sensor in FIG. 31;

FIG. 34 is a block diagram showing an angular velocity detection circuit in the angular velocity detection device of the present invention.

FIG. 35 is a plan view showing an angular velocity sensor according to another embodiment of the present invention.

FIG. 36 is a block diagram showing an angular velocity detection circuit using the angular velocity sensor in FIG. 35;

FIG. 37 is a plan view showing another embodiment of the angular velocity sensor of the present invention.

FIG. 38 is a plan view showing still another embodiment of the angular velocity sensor of the present invention.

FIG. 39 is a partial block diagram of an angular velocity detection circuit in which the electrodes of the piezoelectric element according to the present invention are shared.

FIG. 40 is a cross-sectional view showing an angular velocity sensor having a pair of piezoelectric elements according to the present invention.

FIG. 41 is a plan view showing an angular velocity sensor according to still another embodiment of the present invention.

FIG. 42 is a plan view showing an angular velocity sensor according to still another embodiment of the present invention.

FIG. 43 is an exploded perspective view showing a conventional vibration gyro-type angular velocity sensor.

FIG. 44 is a connection diagram showing a conventional angular velocity detecting device using a vibration gyro type angular velocity sensor.

[Explanation of symbols]

1 silicon substrate (substrate), 2 cantilever (vibrating piece),
3, 31, 32, 33 support pieces, 4, 5 drive electrodes, 4
A, 4B, 4C, 4D, 4E, 4F Piezoelectric element, 6a,
7a detection electrode (first detection electrode pair), 6A, 9 common electrode, 6b, 7b detection electrode (second detection electrode pair), 7
c, 7d detection electrode, 8 common detection electrodes, 14a, 14
b, 15a, 15b, 15c, 15d drive detection electrodes,
16 common drive detection electrodes (common electrodes), 23, 23A
Cantilever (vibrating piece), 24 rectangular vibrating piece, 44 weight,
45a, 45b electrode (lower electrode), 46 piezoelectric film, 4
7a, 47b Electrode (upper electrode), 81, 82 Penetration part.

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) G01C 19/00-19/72 G01P 9/04

Claims (39)

(57) [Claims] 1. A vibration having a substrate and a holding portion fixed to the substrate, and other than the holding portion, the vibration is arranged so as to face and close to the substrate, and bends and deforms mainly in a direction perpendicular to the substrate surface. A piece, a supporting piece that is provided continuously to a part of the vibrating piece and is bent and deformed in a horizontal direction with respect to the substrate surface, and is provided on the vibrating piece and the substrate opposed thereto, respectively. A pair of drive electrodes, the areas of which overlap with each other with respect to horizontal vibration, are provided on the vibrating reed and the substrate opposed thereto, respectively, and are mutually overlapped with respect to the horizontal vibration of the vibrating reed. An angular velocity sensor comprising at least two pairs of detection electrodes having a variable area. 2. A supporting piece having a substrate and a holding portion fixed to the substrate, and a supporting piece other than the holding portion is disposed so as to face the substrate and bend horizontally in the substrate surface. The cantilever which has a halfway and is bent and deformed mainly in the direction perpendicular to the substrate surface on the holding portion side from the support piece, and the cantilever on the holding portion side and the substrate at a position facing the cantilever, respectively. The pair of drive electrodes provided are provided on the cantilever beam on the tip end side of the support piece and on the substrate at a position facing the cantilever beam, and overlap with each other for horizontal vibration on the tip end side. An angular velocity sensor comprising at least two pairs of detection electrodes having a variable area. 3. The angular velocity sensor according to claim 1, wherein the detection electrode is arranged on a tip end side of the vibrating reed or the cantilever with respect to the drive electrode. 4. A vibration having a substrate and a holding portion fixed to the substrate, other than the holding portion, being disposed so as to be opposed to the substrate and being bent and deformed mainly in a direction perpendicular to the substrate surface. A piece, a supporting piece that is provided continuously to a part of the vibrating piece and is bent and deformed in a horizontal direction with respect to the substrate surface, and is provided on the vibrating piece and the substrate opposed thereto, respectively. An angular velocity sensor comprising two pairs of drive detection electrodes whose overlapping areas change with respect to horizontal vibration. 5. The angular velocity according to claim 1, wherein the vibrating reed is a cantilever, and the support piece is provided at one end or in the middle of the cantilever in the axial direction of the cantilever. Sensor. 6. A vibrating piece is a doubly supported beam fixed to a substrate at holding portions at both ends, and supporting pieces are provided at both ends of the doubly supported beam in the axial direction thereof, and a driving electrode, a detecting electrode, 5. The angular velocity sensor according to claim 1, wherein the drive detection electrodes are arranged symmetrically with respect to a center vertical plane in a width direction of the doubly supported beam. 6. 7. A plurality of detection electrodes formed on a vibrating reed, a cantilever beam or a cantilever beam, and any one of a plurality of detection electrodes formed on a substrate side corresponding to these is used as a common detection electrode. Item 7. An angular velocity sensor according to any one of Items 1 to 6. 8. A rectangle which has a substrate and a holding portion fixed to the substrate, and other than the holding portion, is disposed in close proximity to the substrate, and is bent and deformed mainly in a direction perpendicular to the substrate surface. A vibrating piece, a supporting piece connected to each corner of the rectangular vibrating piece and being bent and deformed in the horizontal direction with respect to the substrate surface, and a rectangular vibrating piece and the substrate facing the rectangular vibrating piece. A pair of drive electrodes having an invariable overlapping area with respect to the horizontal vibration of the rectangular vibrating reed;
An angular velocity sensor comprising four pairs of detection electrodes in two horizontal axis directions in which the mutually overlapping areas of the rectangular vibrating piece overlap with each other with respect to the horizontal vibration. 9. A rectangle having a substrate and a holding portion fixed to the substrate, other than the holding portion, being disposed to be close to and facing the substrate, and being bent and deformed mainly in a direction perpendicular to the surface of the substrate. A vibrating piece, a supporting piece connected to each corner of the rectangular vibrating piece and being bent and deformed in the horizontal direction with respect to the substrate surface, and a rectangular vibrating piece and the substrate facing the rectangular vibrating piece. Further, an angular velocity sensor comprising four pairs of drive detection electrodes which are point-symmetric with respect to the center axis of the rectangular vibrating piece, wherein the area of the rectangular vibrating piece overlapping each other with respect to the horizontal vibration changes. 10. A drive electrode and a detection electrode formed on a vibrating reed or a cantilever, and at least one of a drive electrode and a detection electrode formed on a substrate side corresponding to these electrodes is a common electrode. An angular velocity sensor according to any one of claims 1 to 9. 11. The angular velocity sensor according to claim 1, wherein a weight for adjusting the resonance frequency is provided on a part of the upper surface of the resonator element. 12. A vibration having a substrate and a holding portion fixed to the substrate, other than the holding portion, being disposed so as to face the substrate in proximity to the substrate, and being bent and deformed mainly in a direction perpendicular to the substrate surface. A piece, a supporting piece that is provided continuously to a part of the vibrating piece and is bent and deformed in a horizontal direction with respect to the substrate surface, and is provided on the vibrating piece and the substrate opposed thereto, respectively. A pair of drive electrodes, the areas of which overlap with each other with respect to horizontal vibration, are provided on the vibrating reed and the substrate opposed thereto, respectively, and are mutually overlapped with respect to the horizontal vibration of the vibrating reed. At least two pairs of detection electrodes whose areas change, and the above-mentioned vibrations are obtained from the above-mentioned frequency components of the capacitance difference between the above-mentioned detection electrodes when driving the above-mentioned drive electrodes and vibrating the above-mentioned vibrating reed vertically near the resonance frequency. Around one axis An angular velocity detection device comprising: an angular velocity detection circuit that detects an angular velocity. 13. A support piece having a substrate and a holding portion fixed to the substrate, and other than the holding portion, a supporting piece which is disposed close to and opposed to the substrate and which bends and deforms in a horizontal direction with respect to the substrate surface. A cantilever that is held halfway and is bent and deformed mainly in a direction perpendicular to the substrate surface on the holding portion side from the support piece, and provided on the cantilever beam on the holding portion side and the substrate at a position facing the cantilever beam And a pair of drive electrodes provided on the cantilever beam on the distal end side of the support piece and on the substrate at a position facing the cantilever beam, and overlapping with each other for horizontal vibration on the distal end side. And at least two pairs of detection electrodes, each of which varies, and the drive element being driven to oscillate the cantilever beam in the vertical direction near the resonance frequency. Detect angular velocity around beam axis Angular velocity detecting circuit comprising: 14. A vibration having a substrate and a holding portion fixed to the substrate, and other than the holding portion, the vibration is arranged so as to be opposed to and close to the substrate, and bends and deforms mainly in a direction perpendicular to the substrate surface. A piece, a supporting piece that is provided continuously to a part of the vibrating piece and is bent and deformed in a horizontal direction with respect to the substrate surface, and is provided on the vibrating piece and the substrate opposed thereto, respectively. Two pairs of drive detection electrodes whose areas overlapping each other change with respect to horizontal vibration, and when the two pairs of drive detection electrodes are driven in phase to vibrate the vibrating reed vertically in the vicinity of the resonance frequency, An angular velocity detection circuit for detecting an angular velocity about the axis of the vibrating reed from the frequency component of the capacitance difference between the two pairs of drive detection electrodes. 15. A rectangle having a substrate and a holding portion fixed to the substrate, other than the holding portion, being disposed in close proximity to the substrate and bent and deformed mainly in a direction perpendicular to the substrate surface. A vibrating piece, a supporting piece connected to each corner of the rectangular vibrating piece and being bent and deformed in the horizontal direction with respect to the substrate surface, and a rectangular vibrating piece and the substrate facing the rectangular vibrating piece. And a pair of drive electrodes having an invariable area overlapping each other with respect to the horizontal vibration of the rectangular vibrating reed;
Four pairs of detection electrodes in two horizontal axis directions in which the mutually overlapping areas of the rectangular vibrating piece overlap with each other with respect to the horizontal vibration change, and the driving electrodes are driven to cause the vibrating piece to have a vertical resonance frequency. An angular velocity detecting circuit for detecting an angular velocity of each of the rectangular vibrating reeds around each horizontal axis from the frequency component of the capacitance difference between the pair of detection electrodes when vibrating in the vicinity. 16. A rectangle which has a substrate and a holding portion fixed to the substrate, and other than the holding portion, is disposed in close proximity to the substrate and bent and deformed mainly in a direction perpendicular to the substrate surface. A vibrating piece, a supporting piece connected to each corner of the rectangular vibrating piece and being bent and deformed in the horizontal direction with respect to the substrate surface, and a rectangular vibrating piece and the substrate facing the rectangular vibrating piece. And a pair of drive detection electrodes that are point-symmetric with respect to the center axis of the rectangular vibrating piece, wherein the area of the rectangular vibrating piece that overlaps with the horizontal vibration changes,
When each of the drive detection electrodes is driven in phase and the rectangular vibrating piece is vibrated in the vertical direction near the resonance frequency, the sum of the capacitances between the two pairs of drive detection electrodes in each horizontal axis direction is taken as one set. An angular velocity detecting circuit for detecting an angular velocity of each of the rectangular vibrating pieces around each horizontal axis from the frequency components of the capacitance difference of the set. 17. A substrate, comprising: a substrate; and a holding portion fixed to the substrate. Other than the holding portion, the holding portion is disposed so as to face one surface of the substrate, and is at least partially vertically perpendicular to the substrate surface. A vibrating piece that bends and deforms in a direction, a supporting piece that is connected to a part of the vibrating piece and that bends and deforms in a horizontal direction with respect to the substrate surface, and a vibrating piece provided on one surface of the vibrating piece in a predetermined direction. An angular velocity comprising: a piezoelectric element polarized to expand and contract; and at least two pairs of detection electrodes formed on the vibrating reed and the substrate, respectively, and each of which has a mutually overlapping area that changes with respect to horizontal vibration of the vibrating reed. Sensor. 18. The vibrating reed is a cantilever, the support piece is provided on the cantilever support side of the vibrating piece, and the detection electrode is provided on a free end side of the vibrating piece. 2. The angular velocity sensor according to 1. 19. A vibrating reed is a doubly supported beam, a support piece is provided on a doubly supported side of the vibrating piece, and a detection electrode is provided symmetrically with respect to a center vertical plane in a width direction of the vibrating piece. The angular velocity sensor according to claim 17, which is provided. 20. A vibrating reed is a cantilever, a supporting piece is provided in the middle of the vibrating piece, a piezoelectric element is provided on the vibrating piece closer to the holding portion than the supporting piece, and a detection electrode is provided. The angular velocity sensor according to claim 17, wherein the angular velocity sensor is provided symmetrically with respect to a center vertical plane in a width direction of the vibrating reed on a tip end side of the support piece having a high vertical bending rigidity. 21. A substrate and a holding portion fixed to the substrate, and other than the holding portion, the substrate is disposed so as to be opposed to one surface of the substrate, and is bent and deformed mainly in a direction perpendicular to the substrate surface. A rectangular vibrating piece, a supporting piece continuously provided at each corner of the rectangular vibrating piece and bending and deforming in the horizontal direction with respect to the substrate surface, and a supporting piece provided on one side of the rectangular vibrating piece from the center thereof. The piezoelectric element polarized so as to expand and contract in the circumferential direction, and the rectangular vibrating reed and the substrate are respectively provided on the substrate, and the area of the rectangular vibrating reed overlapping with each other in each horizontal direction changes with respect to each horizontal vibration of the rectangular vibrating reed. Angular velocity sensor comprising four pairs of detection electrodes in two horizontal axis directions. 22. A substrate, comprising: a holding portion fixed to the substrate; and other than the holding portion, the substrate is disposed close to and opposed to one surface of the substrate, and is bent and deformed mainly in a direction perpendicular to the substrate surface. A rectangular vibrating piece, a supporting piece continuously provided at each corner of the rectangular vibrating piece and bending and deforming in the horizontal direction with respect to the substrate surface, and a supporting piece provided on one side of the rectangular vibrating piece from the center thereof. The piezoelectric element polarized to expand and contract in the circumferential direction, and the rectangular vibrating reed and the rectangular vibrating reed are respectively provided on the substrate, and the rectangular vibrating reeds have different overlapping areas for horizontal vibration. An angular velocity sensor including four pairs of detection electrodes that are point-symmetric with respect to the center axis of the resonator element. 23. The angular velocity sensor according to claim 17, wherein a weight for adjusting a resonance frequency is provided on a part of the resonator element or the rectangular resonator element. 24. A plurality of detection electrodes formed on a cantilever beam, a cantilever beam, or a rectangular vibrating piece are used as common electrodes.
24. The angular velocity sensor according to any one of claims 23 to 23. 25. A substrate, comprising: a substrate; and a holding portion fixed to the substrate. Other than the holding portion, the substrate is arranged to be close to one surface of the substrate, and at least a part thereof is mainly perpendicular to the substrate surface. A vibrating piece that bends and deforms in a direction, a supporting piece that is connected to a part of the vibrating piece and that bends and deforms in a horizontal direction with respect to the substrate surface, and a vibrating piece provided on one surface of the vibrating piece in a predetermined direction. A piezoelectric element polarized to expand and contract, at least two pairs of detection electrodes provided on the vibrating reed and the substrate, respectively, and having a mutually overlapping area changing with respect to horizontal vibration of the vibrating reed; The angular velocity detection circuit for detecting the angular velocity about the axis of the vibrating reed from the frequency component of the capacitance difference between the pair of detection electrodes when the vibrating reed is vibrated in the vertical direction near the resonance frequency. Angular velocity detection with apparatus. 26. A substrate, comprising: a holding portion fixed to the substrate; and other than the holding portion, the substrate is disposed so as to face one surface of the substrate, and is bent and deformed mainly in a direction perpendicular to the substrate surface. A rectangular vibrating piece, a supporting piece continuously provided at each corner of the rectangular vibrating piece and bending and deforming in the horizontal direction with respect to the substrate surface, and a supporting piece provided on one side of the rectangular vibrating piece from the center thereof. The piezoelectric element polarized to expand and contract in the peripheral direction, the rectangular vibrating reed and the substrate are provided on the substrate, and the area of the rectangular vibrating reed overlapping with each other in the horizontal direction changes with respect to each horizontal vibration of the rectangular vibrating reed. (2) Four pairs of detection electrodes in the horizontal axis direction and the frequency of the capacitance difference between each pair of detection electrodes when the piezoelectric element is driven and the rectangular vibrating piece is vibrated in the vertical direction near the resonance frequency. From the components, the angular velocity around each horizontal axis of the rectangular vibrating piece An angular velocity detecting device comprising an angular velocity detecting circuit for detecting a degree. 27. A substrate having a substrate and a holding portion fixed to the substrate, and other than the holding portion, the substrate is disposed so as to face one surface of the substrate, and is bent and deformed mainly in a direction perpendicular to the surface of the substrate. A rectangular vibrating piece, a supporting piece continuously provided at each corner of the rectangular vibrating piece and bending and deforming in the horizontal direction with respect to the substrate surface, and a supporting piece provided on one side of the rectangular vibrating piece from the center thereof. A piezoelectric element polarized to expand and contract in the peripheral direction, and the rectangular vibration provided on the rectangular vibrating reed and the substrate, wherein an area of the rectangular vibrating reed overlapping with horizontal vibration changes. Four pairs of detection electrodes that are point-symmetric with respect to the central axis of the piece, and two pairs of the horizontal axis directions when the piezoelectric element is driven to vibrate the rectangular vibrating piece in the vertical direction near the resonance frequency. The sum of the capacitances between a pair of detection electrodes An angular velocity detection circuit for detecting an angular velocity of each of the rectangular vibrating pieces around each horizontal axis from the frequency component. 28. A substrate, comprising: a substrate; and a holding portion fixed to the substrate. Other than the holding portion, the holding portion is disposed so as to face one surface of the substrate, and at least a part thereof is mainly horizontal to the substrate surface. An elongated vibrating reed that bends and deforms in a direction, a support piece that is connected to a part of the vibrating reed and that bends and deforms in the horizontal and vertical directions with respect to the substrate surface; A piezoelectric element that is symmetrically provided on a plane perpendicular to the center of the direction, stacked so as to sandwich the piezoelectric film by two pairs of upper and lower electrodes, and polarized so as to expand and contract the vibrating piece in the horizontal direction; An angular velocity sensor comprising: two pairs of detection electrodes formed on the substrate and having mutually overlapping areas that change with respect to horizontal vibration of the resonator element. 29. A substrate having a substrate and a holding portion fixed to the substrate, and other than the holding portion, the substrate is arranged so as to face one surface of the substrate, and at least a part thereof is mainly horizontal to the substrate surface. An elongated vibrating reed that bends and deforms in a direction, a support piece that is connected to a part of the vibrating reed and that bends and deforms in the horizontal and vertical directions with respect to the substrate surface; A piezoelectric element that is symmetrically provided on a plane perpendicular to the center of the direction, stacked so as to sandwich the piezoelectric film by two pairs of upper and lower electrodes, and polarized so as to expand and contract the vibrating piece in the horizontal direction; An angular velocity sensor comprising a pair of detection electrodes formed on the substrate and having a constant facing area with respect to horizontal vibration of the resonator element. 30. The angular velocity sensor according to claim 28, wherein at least one electrode on one side of the piezoelectric element is shared among the two pairs of electrodes of the piezoelectric element. 31. The piezoelectric element according to claim 28, wherein the piezoelectric elements are stacked so as to sandwich each piezoelectric film between each pair of electrodes, and are arranged symmetrically with respect to a center vertical plane in the width direction of the resonator element. 30. The angular velocity sensor according to claim 29. 32. The vibrating reed is a cantilever, the supporting piece is provided on the cantilever support side of the vibrating piece, and the detection electrode is provided on the free end side of the vibrating piece. 2. The angular velocity sensor according to 1. 33. A vibrating reed is a doubly supported beam, a support piece is provided on a doubly supported side of the vibrating piece, and a detection electrode is provided symmetrically on a center vertical plane in a width direction of the vibrating piece. 30. The angular velocity sensor according to claim 28. 34. A vibrating reed is a cantilever, a supporting piece is provided in the middle of the vibrating reed, and the supporting piece is bent in a vertical direction.
The vertical displacement of the vibrating reed from the tip side
30. The angular velocity sensor according to claim 28, wherein the holding part is small, a piezoelectric element is provided on the holding part, and a detection electrode is provided on the tip part. 35. The angular velocity sensor according to claim 28, wherein a penetrating portion is provided in a part of the vibrating reed along a center vertical plane in a width direction of the vibrating reed. 36. A substrate, comprising: a substrate; and a holding portion fixed to the substrate. Other than the holding portion, the substrate is disposed so as to face one surface of the substrate, and at least a part of the substrate is mainly horizontal with respect to the substrate surface. An elongated vibrating reed that bends and deforms in a direction, a support piece that is connected to a part of the vibrating reed and that bends and deforms in the horizontal and vertical directions with respect to the substrate surface; A piezoelectric element that is symmetrically provided on a plane perpendicular to the center of the direction, stacked so as to sandwich the piezoelectric film by two pairs of upper and lower electrodes, and polarized so as to expand and contract the vibrating piece in the horizontal direction; Two pairs of detection electrodes respectively formed on the substrate and having mutually overlapping areas changing with respect to horizontal vibration of the vibrating reed, and driving the piezoelectric element to bend the vibrating reed horizontally near a resonance frequency. Between each pair of detection electrodes when vibrated And an angular velocity detection circuit for detecting an angular velocity of the vibrating reed around the axis from the frequency component of the sum of capacitances. 37. An elongated vibrating reed having a substrate, a holding portion fixed to the substrate, and being bent and deformed mainly in a horizontal direction other than the holding portion, and provided continuously with a part of the vibrating reed. A supporting piece that bends and deforms in the horizontal and vertical directions with respect to the substrate surface; and a piezoelectric film that is provided on one surface of the vibrating piece symmetrically with respect to the central vertical plane in the axial direction of the vibrating piece, and that is sandwiched between two pairs of upper and lower electrodes. And a piezoelectric element that is stacked so as to be polarized so as to expand and contract the vibrating reed in the horizontal direction, and is formed on the vibrating reed and the substrate, respectively, and has a constant area facing the horizontal vibration of the vibrating reed. The axis of the vibrating reed from the frequency components of the capacitance between the detecting electrodes when the pair of detecting electrodes and the piezoelectric element are driven to vibrate the vibrating reed horizontally in the vicinity of the resonance frequency. Angular velocity detection circuit for detecting angular velocity around Speed detector. 38. An angular velocity detection circuit for controlling a driving voltage or a driving current to drive a piezoelectric element at a predetermined vibration speed so that a ratio of a capacitance difference to a sum of capacitances of each pair of detection electrodes is constant. Item 37. The angular velocity detecting device according to Item 36. 39. An angular velocity detection circuit, wherein the voltage or the voltage is applied so that a difference between a current applied to the piezoelectric element and a product of a voltage applied to the piezoelectric element and a braking admittance of the piezoelectric element becomes a predetermined value. 27. The piezoelectric element is driven at a predetermined vibration speed by controlling a current.
An angular velocity detecting device according to any one of claims 36 and 37.