JP2001082964A - Resonant element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resonant element reducing a difference in resonant frequency of a vibrated planar vibrating element between its vibrating direction and detecting direction, and also reducing the deflection of the planar vibrating element in the detecting direction. SOLUTION: A planar vibrating element 10 comprising a weight part 2 is disposed in a floating condition on a substrate 1 having a substrate surface oriented in the direction of an X, Z two-dimensional plane, and is supported on the substrate 1 through a support beam 3 in such a way as to be capable of vibrating in X direction and is vibrated by an exciter 4 in the X direction. The resonant frequency of the planar vibrating element 10 in its vibrating direction is designed to be slightly lower than its resonant frequency in a detecting direction. Conducting layers 23, 24 for imparting electrostatic attracting forces 21, 22 to the planar vibrating element 10 to adjust the resonant frequency of the planar vibrating element 10 in the detecting direction and for correcting the inclination of the planar vibrating element 10 in the direction of the substrate surface of the substrate 1 are provided in areas at both end edges of the planar vibrating element 10 spaced apart from each other in the X direction, on the surface of the substrate 1 spaced from the surface of the planar vibrating element 10 in the Y direction perpendicular to the direction of the X, Z two-dimensional plane.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resonance element used for an angular velocity sensor, a filter, and the like.

[0002]

2. Description of the Related Art FIG. 7 shows a perspective view of a resonance element previously proposed by the present applicant. This resonance element 16
A resonant element 16 of a fine element manufactured by using a conventional silicon micro-machining technique or the like, in which a nitrided film 7 is formed on a silicon substrate 1 and a polysilicon film 5 is formed thereon; These films 7 and 5 are set in a predetermined pattern by dry etching or the like.

[0003] The substrate 1 functions as a fixed substrate having a two-dimensional X, Z plane direction as a substrate surface direction.
On the upper part, the weight part 2 is arranged in a state of floating from the substrate 1,
In the resonance element 16 shown in the figure, the weight 2 functions as the planar vibrator 10. The plane vibrator 10 is supported so as to be able to vibrate in the X direction via the support beams 3, and one end of each support beam 3 is fixed to the substrate 1 via the fixing portion 35.

A comb-shaped electrode 6B is formed on both sides of the plane vibrating body 10 outward in the horizontal direction (X direction).
At a position facing the comb-shaped electrode 6B, the comb-shaped electrode 6A is arranged in a state of being engaged with the comb-shaped electrode 6B toward the inside in the horizontal direction. Driving conductor layers 11A and 11B are connected to these comb-shaped electrodes 6A and 6B, and are connected to external electrode pads (not shown) via conductor patterns (not shown) to form the exciter 4. .

[0005] The drive conductor layers 11A, 11 of the exciter 4
When an AC voltage is applied to B, an electrostatic force is generated between the comb-shaped electrodes 6A and 6B, and the planar force vibrates in the direction of arrow F (X direction) by the electrostatic force.

[0006] The comb-shaped electrode 6A of the resonance element 16 having the above configuration,
6B, and vibrates the plane vibrator 10 in the X direction.
When the resonance element 16 is rotated about the Z axis as a rotation axis, a Coriolis force is generated in a Y direction orthogonal to the X, Z two-dimensional plane direction, and the Coriolis force is applied to the plane vibrating body 10 including the weight 2. The plane vibrator 10 vibrates in the direction of the Coriolis force. By measuring an electric signal corresponding to the magnitude of the vibration amplitude due to the Coriolis force of the plane vibrating body 10 at this time, for example, the magnitude of the angular velocity of rotation can be detected.

When the resonance element 16 is applied as an angular velocity sensor or the like, the plane vibrator 1 due to the Coriolis force is used.
A detection unit for measuring an electric signal corresponding to the magnitude of the vibration amplitude of 0 is provided.

By the way, when manufacturing the resonance element 16,
The resonance frequency of the plane vibrator 10 in the direction of the Coriolis force (Y direction) is set in advance in the design stage to the resonance frequency in the X direction, and the shape, size, weight, and the like of the plane vibrator 10 become the resonance frequency. Design and manufacture. However, the plane vibrator 1
The shape, size, weight, etc. of 0 are often not produced as designed due to the processing accuracy of silicon micromachining technology, and the resonance frequency of the planar vibrator 10 often deviates from the designed frequency. If the vibration of the plane vibrator 10 is in a resonance state, Q (Quality
Although the amplitude is dramatically amplified by the value of (Factor), when the frequency is shifted, amplification is hardly performed, and there is a problem that the sensitivity of the resonance element is significantly reduced. For this reason, it is necessary to trim the weight portion 2 and the support beam 3 by, for example, troublesome machining or the like, and adjust the resonance frequency of the planar vibrating body 10 to a design set frequency.

However, since the resonance element 16 is a fine resonance element 16 manufactured by applying the silicon micromachining technology, a minute trimming adjustment necessary for obtaining a desired resonance frequency by using machining is performed. Even if an attempt is made to trim the portion, it is almost impossible to cut the fine weight portion 2 and the support beam 3 into desired dimensions, shapes, weights, etc. from the viewpoint of processing accuracy by complicated machining. Therefore, it was extremely difficult to adjust the resonance frequency of the planar vibrator 10 to a set value.

Therefore, in the resonance element 16 proposed above, as shown in FIG.
At a position opposed to the Y-direction with an interval therebetween.
Is provided. This conductive layer 12
Is connected to the conductive pads 14 through the conductive patterns 13 as shown in FIG. 7A, and controls the voltage applied to the conductive layer 12 through the conductive patterns 13 and the conductive pads 14. Thereby, the resonance frequency of the resonance element 16 can be adjusted to the set value.

When a DC voltage is applied to the conductive layer 12, an electrostatic force acts on the planar vibrator 10, which acts on the planar vibrator 10 as an electrostatic spring. That is, the plane vibrator 1
Since the electrostatic force acts in the direction of increasing the amplitude when 0 vibrates in the direction approaching the substrate 1, there is an effect of generating a force in the direction opposite to the mechanical spring, and as a result, the Y of the planar vibrator 10 Decrease the resonance frequency in the direction. Since the amount of decrease in the resonance frequency changes in accordance with the applied electrostatic attraction 15, by adjusting the magnitude of the DC voltage applied to the conductive layer 12, the resonance frequency inherent in the planar vibrator 10 can be reduced to a low frequency. Side can fine-tune the resonance frequency.

If this effect is used, the resonance frequency in the Y direction inherent to the plane vibrator 10 is designed to be slightly higher than the most sensitive resonance frequency (the resonance frequency in the X direction) (in other words, the exciter is excited). If the resonance frequency in the detection direction is designed to be higher than the resonance frequency in the vibration direction of the plane vibrating body 10 according to (4), by adjusting the DC voltage applied to the conductive layer 12, the sensitivity of the resonance element 16 can be increased. Can be adjusted.

[0013]

By the way, in the above-described resonance element 16, it is important to set the resonance frequency to a set value, and it is very important to make the vibration state of the planar vibrator 10 accurate. Is important. FIG. 6 shows an example of the motion of the planar vibrating body 10 in the XY plane when the planar vibrating body 10 is vibrated in the X direction in the resonance element 16 when there is no angular velocity around the Z axis. In the resonance element 16 as shown in FIG.
(A), the vibration state of the planar vibrating body 10 is blurred in the Y direction, which is the direction in which the Coriolis force is detected (substrate 1).
(The inclination of the planar vibrating body 10 with respect to the substrate surface direction is large)
In this case, the Coriolis force cannot be accurately detected, and the gyro characteristics of the angular velocity sensor and the like deteriorate.

Therefore, as shown in FIG. 6B, it is desirable that the vibration state of the plane vibrator 10 has almost no fluctuation in the Y direction.

In general, the smaller the difference (Δf) between the vibration direction of the plane vibration body 10 and the resonance direction in the detection direction becomes, the smaller the mechanical coupling between the two directions (propagation and interaction of mechanical energy between both vibration modes). Becomes large, and the fluctuation in the detection direction when the resonance element 16 is driven tends to be large. In particular, dimensional errors during device fabrication, residual stress, and the like increase the mechanical coupling.

Therefore, in order to increase the sensitivity of the resonance element 16, even if the difference (Δf) between the vibration direction of the planar vibrating body 10 and the resonance frequency in the detection direction is reduced, on the other hand, the detection direction shifts. If the amount is large, the Coriolis force cannot be detected accurately. For this reason, just by providing the conductive layer 12 and reducing the difference (Δf) between the resonance frequencies as in the proposed resonance element 16, it was not possible to obtain an accurate resonance element 16 with high sensitivity. . Therefore, conventionally, the difference (Δ
It was difficult to obtain the resonance element 16 having a small f) and a small deviation in the detection direction, and the yield of the resonance element 16 satisfying both characteristics was extremely low.

In the conventional resonance element 16 having dimensional variations, it is possible in principle to perform mechanical trimming so as to reduce the amount of deviation of the planar vibrator 10 in the detection direction. Although it may be, it is not practical to perform the mechanical trimming operation while evaluating the shake amount of the plane vibrating body 10.

After the trimming, the amount of shake of the plane vibrating body 10 is checked, and thereafter, the trimming is performed again, and the amount of shake of the plane vibrating body 10 after the trimming is confirmed. Approaching zero is an extremely time-consuming and impractical task. Therefore, without performing such an operation, the difference between the vibration frequency of the plane vibration body 10 and the resonance frequency in the detection direction (Δ
It has been desired to develop a resonance element 16 having a small f) and a small fluctuation in the detection direction.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to eliminate the need for troublesome trimming processing and to reduce the resonance between the vibration direction and the detection direction of a plane vibrator vibrating due to Coriolis force. An object of the present invention is to provide a resonance element having a small frequency difference (Δf) and a small vibration of a plane vibrator in a detection direction.

[0020]

The present invention is configured as follows to achieve the above object. That is, in the first invention, a weight portion is arranged in a state of being floated on a fixed substrate with the X-Z two-dimensional plane direction as a substrate surface direction, and a planar vibrator having the weight portion is supported on the fixed substrate by a support beam. Is supported so as to be able to vibrate in the X direction via the
An exciter that oscillates in the direction is provided, and an opposing surface side that is spaced from the plane of the planar vibrator in the Y direction orthogonal to the X, Z two-dimensional plane direction has an interval in the X direction. At least both end edge regions of the plane vibrator, adjust the resonance frequency of the plane vibrator by applying electrostatic attraction to the plane vibrator,
The present invention is a means for solving the problem with a configuration in which a vibrating body inclination correcting means for correcting the inclination of the planar vibrating body with respect to the substrate surface direction of the fixed substrate is provided.

According to a second aspect of the present invention, there is provided the configuration of the first aspect, wherein the planar vibrator is provided with a frame suspended on a fixed substrate and a connecting beam inside the frame. And a weight portion connected to the surface of the planar vibrator at a distance in the Y direction on a side opposite to at least both end edge regions of the weight portion with a distance in the X direction. A vibrating body inclination correcting means is provided, and a second vibrating body inclination correcting means is provided at a position facing the frame and sandwiching the first vibrating body inclination correcting means with an interval in the X direction. It is characterized by being provided.

Further, the third invention is directed to the first or second embodiment.
Stress canceling means for directly or indirectly applying, to the support beam, a force in a direction for canceling the tensile stress of the support beam caused by the application of the electrostatic attractive force to the plane vibrator by the vibrating body inclination correcting means. Is provided.

In a fourth aspect of the present invention, the stress canceling means of the third aspect faces the vibrating body inclination correcting means via the plane of the planar vibrator, and the plane canceling means uses the vibrating body inclination correcting means. A structure in which the body is sandwiched with a gap therebetween to apply an electrostatic attraction to the plane vibrator and cancel the tensile stress of the support beam caused by the electrostatic attraction applied to the plane vibrator by the vibrator inclination correcting means. It is characterized by the fact that

Further, a fifth aspect of the present invention comprises the configuration of any one of the first to fourth aspects of the present invention, wherein a vertical movement side electrode is provided on at least one of a front surface and a back surface of the weight portion. A fixed counter electrode is provided on the side opposite to the vertical movement side electrode at an interval in the Y direction, and a pair of the vertical movement side electrode and the fixed counter electrode is a weight part corresponding to a change in angular velocity of rotation about the Z axis. It is characterized in that it is formed as a Z-axis angular velocity detection electrode for detecting the vibration amplitude in the Y direction.

Further, a sixth aspect of the present invention comprises the configuration of any one of the first to fourth aspects of the invention, wherein the weight portion is formed of silicon or polysilicon, and the weight portion itself is on the vertical movement side. An electrode is provided, and a fixed counter electrode is provided on the opposite side of the weight portion with an interval in the Y direction, and a set of the weight portion and the fixed counter electrode corresponds to a change in angular velocity of rotation about the Z axis. It is characterized in that it is formed as a Z-axis angular velocity detection electrode for detecting the vibration amplitude of the weight portion in the Y direction.

In the present specification, the term "end edge region" is used in a broad concept including an area slightly inside and an area slightly outside the end edges of the plane vibrator and the weight.

In the invention having the above structure, the plane vibrator having the weight portion is supported on the fixed substrate via a support beam so as to be able to vibrate in the X direction, and the vibrator inclination correcting means is provided on the plane vibrator. The resonance frequency of the planar vibrator is adjusted by applying electrostatic attraction, and the inclination of the planar vibrator with respect to the substrate surface direction of the fixed substrate is corrected. As described above, the adjustment of the resonance frequency of the planar vibrator and the correction of the inclination of the planar vibrator with respect to the direction of the substrate surface of the fixed substrate can be performed by the vibrator tilt correcting means.

Accordingly, the difference between the vibration direction of the plane vibrating body vibrating due to the Coriolis force and the resonance frequency in the detecting direction can be reduced without performing a troublesome trimming process. Blur can be reduced.

[0029]

Embodiments of the present invention will be described below with reference to the drawings. In the following description of the embodiment, the same reference numerals are given to the same names as those in the above-mentioned proposal example, and the detailed description thereof will be omitted.

FIG. 1 shows a first embodiment of the resonance element according to the present invention. Resonant element 1 of first embodiment
Reference numeral 6 denotes a fine element manufactured by using a silicon micromachining technique or the like, similarly to the above-described proposal example, and is applied to an angular velocity sensor or the like.

As in the case of the proposal shown in FIG. 7, the resonant element 16 of the first embodiment has a planar vibrator 10 formed by dry etching or the like and an exciter utilizing the electrostatic force of the comb-shaped electrodes 6A and 6B. 4 is provided.

By the way, the plane vibrator 10 as described above
It has been found that the main cause of the vibration fluctuation in the detection direction is that the plane vibrator 10 is inclined with respect to the substrate surface direction of the fixed substrate 1. Thus, in the first embodiment, a unique vibrating body inclination correcting means for adjusting the resonance frequency of the planar vibrating body 10 and correcting the inclination of the planar vibrating body 10 with respect to the substrate surface direction of the substrate 1 is provided.

That is, in the first embodiment, FIG.
As shown in (b), the two conductive layers 23 and 24 are placed on the surface of the substrate 1 which is a surface facing the surface of the planar vibrating body 10 with an interval in the Y direction. The conductive layers 23 and 24 are provided in both end edge regions of the body 10 to adjust the resonance frequency of the plane vibration body 10 by applying electrostatic attraction 21 and 22 to the plane vibration body 10, Vibration body inclination correction means for correcting the inclination of the plane vibration body 10 with respect to the plane direction.

As shown in FIG. 1A, the conductive layer 23 is connected to a conductive pad 27 via a conductive pattern 25, and the conductive layer 24 is connected to a conductive pad 28 via a conductive pattern 26. I have.

In the first embodiment, the plane vibrator 1
Resonance frequency in the detection direction of 0 (for example, fy = 5.5 Hz)
Is slightly higher (for example, 500) than the resonance frequency (for example, fx = 5 kHz) in the vibration direction of the planar vibrating body 10 by the exciter 4.
Hz) Designed to be higher.

FIG. 2 shows a manufacturing process of the resonance element of the first embodiment. First, as shown in FIG. 2A, a nitride film 7 is formed on the outer peripheral side of a silicon substrate 1 and a vibrating body tilt correction doped with phosphorus P or boron B is formed on a central portion of the substrate 1. The conductive layers 23 and 24 as means are
It is formed at intervals in the direction. The conductive layers 23 and 24
Are formed at both end edge regions of the weight 2 (the plane vibrating body 10) formed in a state of being floated on the substrate 1 in a later step.

Thereafter, as shown in FIG. 1B, a sacrifice layer 8 such as an oxide film is formed on the conductive layers 23 and 24 so as to straddle the nitride film 7 on the outer peripheral side.

Next, as shown in FIG. 1C, a polysilicon film 5 is formed on the nitride film 7 and the sacrificial layer 8, and patterns such as the weight 2 and the comb-shaped electrodes 6A and 6B are formed.
Then, as shown in FIG. 1D, for example, the sacrificial layer 8 is removed by dry etching or the like, and the weight portion 2 is formed in a state of floating on the substrate 1 via the gap 9 to form the planar vibrator 1.
0, and the conductive layer 2
The resonance element 16 is manufactured with the elements 3, 24 facing each other.

The resonance element 16 of the first embodiment is manufactured as described above, and is configured as shown in FIG. As described in the above-described proposal, by driving the exciter 4 of the resonance element 16, the plane vibrator 10 can be vibrated in the X direction orthogonal to the length of the support beam 3, and in this state, When rotated about the Z axis as a rotation axis, a Coriolis force is generated in the Y direction. This Coriolis force is applied to the planar vibrator 10
And the plane vibrator 10 oscillates in the direction of the Coriolis force (Y direction). By measuring the magnitude of this amplitude,
Angular velocity can be detected.

In the first embodiment, the plane vibrator 1
Since the conductive layers 23 and 24 are provided as means for correcting the inclination of 0, the conductive pad 2
DC voltages are individually applied to the conductive layers 23 and 24 via the conductive layers 7 and 28, and both ends of the planar vibrating body 10 facing the conductive layers 23 and 24 as shown in FIG. The partial area can be pulled toward the substrate 1 by the electrostatic attraction 21 and 22 to correct the inclination of the planar vibrating body 10.
As described above, by performing the inclination correction of the planar vibrating body 10, it is possible to correct the vibration of the planar vibrating body 10 in the detection direction.

Specifically, when the plane vibrating body 10 vibrates,
For example, as shown by a dashed line A in FIG. 1B, when the plane vibrating body 10 tilts downward to the right, a DC voltage higher than the DC voltage applied to the conductive layer 24 is applied to the conductive layer 23, and By pulling the edge region of the planar vibrator 10 facing the substrate 23 more strongly than the edge region of the planar vibrator 10 facing the conductive layer 24,
The inclination is corrected.

Contrary to the above, when the plane vibrating body 10 tilts to the left as shown by the broken line B in FIG. 1B, a DC voltage larger than the DC voltage applied to the conductive layer 23 is applied. Applied to the conductive layer 24. Then, the edge region side of the planar vibrating body 10 facing the conductive layer 24 is connected to the conductive layer 2.
The tilt is corrected by pulling the planar vibrator 10 toward the substrate 1 more strongly than the edge region of the planar vibrator 10 facing the third vibrator 3.

Further, the conductive layers 23 and 24 are
It functions as a means for correcting the inclination of 0, and also functions as a means for adjusting the resonance frequency of the planar vibrator 10. That is, the planar vibrating body 1 is generated by the electrostatic attraction 21 and 22 caused by the application of the DC voltage to the conductive layers 23 and 24.
By pulling 0 toward the substrate 1, the resonance frequency of the plane vibrator 10 in the detection direction can be reduced. For this reason, the resonance frequency in the detection direction of the planar vibrating body 10 is designed to be slightly higher than the frequency in the vibration direction, and the planar vibrating body 10 is pulled toward the substrate 1 by the electrostatic attraction 21 and 22 so that The resonance frequency in the detection direction of the vibrating body 10 is reduced, and the resonance frequency difference (Δf) between the driving direction and the detection direction of the planar vibrating body 10 is adjusted to be small.

That is, in the first embodiment, the conductive layer 2
By adjusting the DC voltage applied to the plane vibrators 10 and 11, the inclination of the plane vibrator 10
In this case, the resonance frequency in the detection direction is lowered by an appropriate value, whereby the resonance frequency difference (Δf) between the driving direction of the planar vibrating body 10 and the detection direction can be adjusted to be small.

For example, in the resonance element 16, the conductive layer 2
When no DC voltage is applied to the conductive layers 3 and 24, or when a DC voltage of the same magnitude is applied to the conductive layers 23 and 24, respectively, the displacement amount in the driving direction (X direction) of the planar vibrating body 10 is The displacement (blur) in the detection direction (Y direction) is 5
%. At this time, first, for example, the voltage applied to the conductive layer 23 is set to 0, and the DC voltage applied to the conductive layer 24 is changed between 0 and 20 V (or conversely, the voltage applied to the conductive layer 24 is set to 0). And the conductive layer 2
3 is changed between 0 and 20 V). Thereby, the inclination of the plane vibrating body 10 is corrected, and the applied voltage value which makes the displacement in the detection direction to the displacement amount in the driving direction of the plane vibrating body 10 2% or less is obtained.

Assuming that when the voltage applied to the conductive layer 23 is 0 and the DC voltage applied to the conductive layer 24 is 10 V, the displacement (blur amount) can be reduced to 2% or less.
Next, a DC voltage of (0 + α) V is applied to the conductive layer 23, and a DC voltage of (10 + β) V is applied to the conductive layer 24 (α and β are both positive values. Do). Then, since the resonance frequency in the detection direction designed to be higher than the resonance frequency in the vibration direction of the planar vibrator 10 can be adjusted to be small, the resonance frequency difference (Δf) between the drive direction and the detection direction is adjusted to be small.

By such adjustment, the amount of deviation in the detection direction due to the inclination of the plane vibrator 10 with respect to the surface of the substrate 1 is reduced by 2%.
In addition, the resonance frequency difference (Δf) between the driving direction and the detection direction can be adjusted to be small. For example, the detection sensitivity of the resonance element 16 is changed from 0.9 degree / sec. To 0.3 degree /
It has been experimentally confirmed that the temperature is improved to about sec.
A detection sensitivity (resolution) improvement of about 0.9 / 0.3) was confirmed. Note that, depending on the state of the planar vibrator 10 and the support beam 3 and the magnitude of the DC voltage applied to each of the conductive layers 23 and 24, a three-fold or more improvement in detection sensitivity can be expected.

According to the first embodiment, as described above, the conductive layers 23 and 24 as vibrating body inclination correcting means for adjusting the resonance frequency of the plane vibrating body 10 and correcting the inclination are spaced apart from each other in the X direction. The substrate 1 is provided at a position opposing the plane vibrator 10 via the substrate 1 and the DC voltage value applied to the conductive layers 23 and 24 is appropriately adjusted, so that the resonance between the driving direction and the detection direction of the plane vibrator 10 is achieved. The frequency difference can be reduced, and the inclination of the planar vibrator 10 can be reduced. For this reason, the resonance element 16 has high sensitivity and low noise even without trimming the plane vibrating body 10 and the support beam 3 irrespective of errors caused in the manufacturing process and changes in the use environment. A small and excellent resonance element 16 can be obtained.

In particular, in the first embodiment, the conductive layer 2
3 and 24, the plane vibrating body 1 having a space therebetween in the X direction.
0, the distance between the position of the center of gravity of the weight 2 as the plane vibrator 10 and the position where the electrostatic forces 21 and 22 are applied to the weight 2 is increased. Therefore, the inclination of the planar vibrating body 10 is reduced by the small electrostatic forces 21 and
2 can be corrected, and the magnitude of the voltage applied to the conductive layers 23 and 24 via the conductive pads 27 and 28 can be reduced. Therefore, the size of the resonance element 16 can be suppressed, and the resonance element 16 can be small.

In the first embodiment, for example, as shown by the dashed line in FIG. 2D, the vertical movement side electrode 30 is provided on the surface of the weight 2 so that the vertical movement side electrode 30 and Y
A fixed opposing electrode 31 is provided on the opposing side with an interval in the direction.
If the electrode is configured as a Z-axis angular velocity detection electrode for detecting the vibration amplitude in the Y direction of the weight portion 2 corresponding to the angular velocity change of the rotation around the axis, as described above, the Y generated by the rotation around the Z-axis can be obtained.
The angular velocity can be detected by detecting the Coriolis force in the direction.

When the fixed counter electrode 31 is provided on the side opposite to the substrate 1 as described above, as shown by a chain line in FIG. Preferably, the resonance element 16 is formed by fixing the cover 32 to the polysilicon film 5 by anodic bonding at the bonding portion 34. Note that the resonance element 16 can also be formed by attaching a metal such as gold to the bonding portion 34 in advance by vapor deposition or the like and eutectic bonding the bonding portion 34.

FIG. 3A is a perspective view showing a configuration of a main part of a second embodiment of the resonance element according to the present invention, and FIG. B- shown in (a)
A cross-sectional view of B 'portion is shown. In the description of the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will not be repeated.

The resonance element of the second embodiment is an angular velocity sensor. The second embodiment is different from the first embodiment in that, first, FIG. As shown in the figure, the planar vibrator 10 has a configuration in which the frame 36 is arranged in a state of being floated on the substrate 1 and the weight 2 connected to the inside of the frame 36 via the connection beam 40. Second, as shown in FIG. 3B, conductive layers 23A and 24A as first vibrating body tilt correcting means and conductive layers 23B and 24B as second vibrating body tilt correcting means are provided. That is, the resonance element 16 is configured. Conductive layers 23A, 24A
Are provided on the substrate 1 on the side opposite to the plane of the plane vibrating body 10 in the Y direction, on both end edge regions of the weight 2 with an interval in the X direction. 24B is
It is provided at a position facing the frame 36 and sandwiching the conductive layers 23A and 24A with an interval in the X direction.

Conductive layers 23A, 24A, 23B, 24B
Are respectively connected to conductive pads (not shown) via separate conductive patterns (not shown). In the second embodiment, the DC voltage applied to each conductive pad is adjusted by adjusting the DC voltage applied to each conductive pad. , Plane vibrator 1
By applying electrostatic attraction 21A, 22A, 21B, 22B to 0, the resonance frequency of the planar vibrator 10 is adjusted, and the inclination of the planar vibrator 10 with respect to the substrate surface direction of the substrate 1 is corrected.

In the second embodiment, the weight 2
Is formed of, for example, silicon or polysilicon, and the weight 2 itself functions as the vertical movement side electrode 30. A fixed opposing electrode 31 is provided on the substrate 1 on the opposing side of the weight 2 with an interval in the Y direction. The combination of the weight 2 (vertical moving side electrode 30) and the fixed counter electrode 31 is Z
It is configured as a Z-axis angular velocity detection electrode that detects the vibration amplitude in the Y direction of the weight 2 corresponding to the angular velocity change of rotation around the axis.

In the second embodiment, the substrate 1 is a glass substrate, and a thickness of 50
The vibrator having the plane vibrator 10 and the support beam 3, the fixed portion 35, and the like are formed by processing a silicon layer of μm.
In the second embodiment, similarly to the proposal and the first embodiment, a driving conductor layer (not shown) is connected to the comb-shaped electrodes 6A and 6B. The exciter 4 is formed by being connected to an external electrode pad (not shown) through the intermediary.

Further, two connecting beams 40 are provided on the right side of the weight 2 along the Z direction orthogonal to the X direction which is the vibration direction of the plane vibrating body 10. Is connected to the right side of the figure of the right-angled quadrilateral frame 36. The connecting beam 40 has a thickness in the Y direction, which is the detection vibration direction of the weight portion 2, smaller than 50 μm, and the rigidity in the Y direction is smaller than the rigidity in the X direction, which is the vibration direction of the planar vibrator 10. Further, the support beam 3 is formed such that the rigidity in the X direction, which is the vibration direction of the planar vibrating body 10, is smaller than the rigidity in the Y direction, which is the detected vibration direction of the weight 2.

In the figure, reference numeral 50 denotes a depression serving as a cavity, reference numeral 20 denotes a connection electrode to the weight 2 (vertical moving side electrode 30), and reference numeral 33 denotes a connection electrode to the fixed counter electrode 31. .

The second embodiment is configured as described above. In the second embodiment, the conductive layers 23A and 23A are located at positions corresponding to both end edge regions of the weight 2 of the planar vibrator 10.
4A, and the weight portion 2 is formed by electrostatic attraction 21A, 22A.
To the substrate 1 side, and furthermore, these conductive layers 23
A and 24A are sandwiched between the conductive layers 23B and 24B at positions corresponding to the frame 36 so that the electrostatic attractive forces 21B and 22B are provided.
Thus, the frame 36 can be pulled toward the substrate 1. Therefore, the resonance frequency in the Y direction of the planar vibrator 10 having the weight 2 and the frame 36 can be adjusted, and the inclination of the weight 2 and the frame 36 with respect to the surface of the substrate 1 can be individually corrected.

Therefore, the second embodiment can also provide the same effects as those of the first embodiment.

In the second embodiment, the planar vibrator 10 has a structure having the frame 36 and the weight 2, and
The rigidity in the Y direction of the connecting beam 40 connecting the weight 6 and the weight 2 is X
The rigidity in the X direction of the support beam 3 that supports the planar vibrating body 10 is smaller than the rigidity in the Y direction. Thus, when the plane vibrating body 10 vibrates in the X direction and rotates around the Z axis, only the weight 2 vibrates in the Y direction, and the frame body 36 can hardly vibrate in the Y direction. Therefore, the comb-shaped electrode 6B is
Does not shift in the Y-axis direction with respect to the
Can stably generate excitation vibration with the amplitude of the voltage applied to the driving conductor layer, and can more accurately detect the rotational angular velocity about the Z axis.

Further, in the second embodiment, since the connecting beam 40 is provided along the Z direction orthogonal to the X direction which is the vibration direction of the planar vibrating body 10, the acceleration caused by the vibration of the planar vibrating body 10 Is the weight 2
This does not affect the Coriolis force that occurs in the Y-axis direction because it does not occur in the torsional direction and does not affect the vertical direction, and the rotation angular velocity around the Z-axis can be detected more accurately. it can.

Hereinafter, a third embodiment will be described. The feature of the third embodiment is that a stress canceling means is provided. The other configurations are the same as those of the above-described embodiments. In the description of the third embodiment, the same components as those of the above-described embodiments are denoted by the same reference numerals, and the description of the common portions will not be repeated. I do.

When the vibrating body inclination correcting means (conductive layers 23 and 24) as described in each of the above embodiments is provided and the planar vibrating body 10 is pulled toward the substrate 1 by electrostatic attraction, the tensile stress is applied to the support beam 3. Occurs. Due to the tensile stress of the support beam 3, the vibration amplitude of the planar vibrating body 10 is reduced and the sensitivity of the resonance element 16 is slightly lowered, or the vibration of the planar vibrating body 10 is instantaneously disturbed and noise is generated in the electric signal for detection. It is feared that this will occur.

Therefore, in the third embodiment, the above-described stress canceling means is provided to apply a force to the support beam 3 in a direction to cancel the tensile stress of the support beam 3. FIG. 4A shows an example in which the above-described stress canceling means is added to the resonance element 16 of FIG. 1, and FIG. 4B shows the case where the above-described stress cancellation means is added to the resonance element 16 of FIG. An example in which is added. These figures 4
(A) and (b), in the third embodiment, the conductive layers 41 and 42 (41
A, 41B, 42A, and 42B) pass through the plane of the planar vibrating body 10 and the vibrating body inclination correcting means (the conductive layers 23 and 24 (2
3A, 23B, 24A, 24B)), and is provided in such a manner that the plane vibrating body 10 is sandwiched by the vibrating body inclination correcting means with an interval therebetween.

The conductive layers 41 and 42 (41A, 41B,
42A, 42B), a DC voltage is applied via a conductive pattern or the like (not shown).
These conductive layers 41, 42 (41A, 41B, 42A, 4
2B), a DC voltage is applied to these conductive layers 41, 4
2 (41A, 41B, 42A, 42B) and planar vibrator 1
An electrostatic attractive force in the direction of attracting each other is generated between 0, and the plane vibrating body 10 is pulled upward in FIG.

As a result, a force in a direction to cancel the tensile stress caused by the vibrating body inclination correcting means is indirectly applied to the support beam 3. From this, the conductive layer 41,
By adjusting the magnitude of the DC voltage applied to 42 (41A, 41B, 42A, 42B), it is possible to substantially cancel the tensile stress of the support beam 3. For example, the magnitude of each electrostatic attraction applied to the plane vibrator 10 by applying a DC voltage to each of the conductive layers 23, 24, 41, and 42 shown in FIG. 4A is represented by F23, F24, F41, and F42, respectively. Then, the magnitude of the DC voltage applied to each conductive layer 23, 24, 41, 42 is determined so that the equation of F23 + F24 = F41 + F42 holds. Thereby, the tensile stress of the support beam 3 can be almost canceled.

According to the third embodiment, a structure is provided in which the stress canceling means is provided, and unnecessary tensile stress is canceled on the support beam 3 by the stress canceling means.
Various problems caused by the tensile stress of the support beam 3 can be reliably avoided. The planar vibrating body 10 can ideally vibrate, and can provide a resonance element with higher sensitivity and lower noise.

It should be noted that the present invention is not limited to the above embodiments, but can adopt various embodiments. For example, in the above-described first embodiment, the conductive layers 23 and 24 are provided only in the both end edge regions of the planar vibrating body 10.
The conductive layers 23 and 24 may be provided in at least both end edge regions of the planar vibrating body 10 and in other regions.
May be provided. Further, in the above-described first embodiment, the planar vibrator 10 (weight portion 2) is formed of polysilicon, but may be formed of silicon. Also, the first
When the resonance element 16 shown in the embodiment is used as an angular velocity sensor, the vertical movement-side electrode 30 is provided in the weight 2. However, the weight 2 itself made of silicon may function as the vertical movement-side electrode. Good.

In the second embodiment, the weight 2
The conductive layers 23A and 24A as the first vibrating body inclination correcting means are provided only in both end edge regions of the conductive layers 23A and 24A.
24A may be provided in at least both end edge regions of the weight portion 2, and the conductive layers 23A and 24A may be provided in other regions. However, as shown in FIG. 3A, when the fixed counter electrode 31 is provided below the weight 2, the conductive layers 23 </ b> A and 24 </ b> A are located at positions avoiding the portion where the fixed counter electrode 31 is provided. Is provided.

Further, in the second embodiment, the connecting beam 40 is provided on the right side of the weight 2 and the weight 2 is connected to the right side of the frame 36 by the connecting beam 40. The weight 40 may be provided on the left side of the weight 2, or the connecting beams 40 may be provided on both sides of the weight 2, and the weight 2 may be connected to the frame 36 in a double-supported state. Further, the connecting beam 40 may be provided along the X direction. However, by providing the connecting beam 40 along the Z direction, as described above, the rotational angular velocity about the Z axis can be detected without being affected by the acceleration caused by vibration.
It is desirable to provide in the direction.

As shown in FIGS. 5A and 5B, when the frame body 36 is provided to constitute the planar vibrating body 10 as in the second embodiment, as shown in FIGS. The leading ends of the short sides 46 of the L-shaped connecting beams 40 are connected to the four corners, respectively, and the long sides 47 of the L-shaped connecting beams 40 are arranged along the sides of the weight 2 with an interval therebetween. The L-shaped short side 46 may be extended toward a corner to which the distal end is connected, and the extended distal end may be connected to the frame 36 side.

Also in this case, as shown in these figures, the conductive layers 23A, 23A
24A, 23B, 24B and conductive layers 23A, 24
A, 23B, conductive patterns 25A, 2 connected to 24B
6A, 25B, 26B and conductive pads 27A, 28A, 2
7B and 28B, the weight 2 is pulled toward the substrate 1 by the electrostatic attraction 21A and 22A, and the electrostatic attraction 21B and 2B are pulled.
By pulling the frame 36 toward the substrate 1 by 2B,
The same effects as those of the second embodiment can be obtained. Also, in the resonance element 16 in the form shown in FIG. 5, as shown in FIG. 4C, the conductive layers 41A, which are the stress canceling means as described in the third embodiment, are used.
By providing 41B, 42A and 42B, the third
The same effects as in the embodiment can be obtained.

Further, in the first and second embodiments, the conductive layers 23 and 24 extending along both sides of the planar vibrator 10 are formed. The configuration may be such that the conductor layers are arranged and formed along both sides of the planar vibrating body 10. In this case, it is desirable that at least the fine conductor layer facing the four corners of the quadrilateral planar vibrator 10 is provided.

Further, in the above-described second embodiment, the weight 2 itself functions as a vertical movement side electrode. However, a separate vertical movement side electrode 30 is provided on at least one of the front side and the back side of the weight 2. It may be provided. When the vertical movement side electrode 30 is provided on the surface side of the weight part 2, for example, FIG.
As in the state shown in FIG.
The fixed counter electrode is provided on the cover 32 and the like.

Further, in the first embodiment, a vertically movable electrode 30 may be provided on the back surface of the weight 2 and a fixed counter electrode 31 may be provided on the substrate 1 at a position facing the weight 2.

Further, in the first and second embodiments, the conductive layer 2 functioning as a vibrating body inclination correcting means is used.
3, 24 (23A, 23B, 24A, 24B) is the substrate 1
However, when a cover 32 that covers the planar vibrating body 10 is provided as shown in FIG. 2D, the conductive layers 23 and 24 (23A, 23B, 24A, 24A) are provided.
B) may be provided on the cover 32 instead of the substrate 1. Also in this case, similarly to the above embodiments, the conductive layers 23, 2
Reference numerals 4 are provided in both end edge regions of the plane vibrating body 10. In addition, the conductive layer 2 that functions as the vibrating body inclination correcting means as described above.
In the case where the cover 3 is provided on the cover 32, the conductive layer 4 serving as the stress canceling means shown in the third embodiment is used.
1 and 42, the conductive layers 41 and 42
Is provided on the substrate 1 so as to face the conductive layers 23 and 24 with the plane of the plane vibrator 10 therebetween and sandwich the plane vibrator 10 between the conductive layers 23 and 24.

Further, in the third embodiment, the force in the direction of canceling the tensile stress of the support beam 3 is applied to the support beam 3 indirectly. A conductive layer serving as a stress canceling means may be provided so that an attractive force is applied.

Further, in each of the above embodiments, the plane vibrating body 10 is fixed at both ends.
0 may be a one-side fixed type (cantilever type).

Further, in each of the above embodiments, the example in which the resonance element 16 is applied to the angular velocity sensor has been described.
The resonance element of the present invention can be used in fields other than the angular velocity sensor.

[0081]

According to the present invention, since the vibrating body tilt correcting means is provided, the vibrating body tilt correcting means adjusts the resonance frequency of the planar vibrating body, and adjusts the plane vibration of the fixed substrate with respect to the substrate surface direction. The correction of the body inclination can be performed together. Therefore, it is possible to reduce the difference between the resonance frequency of the vibration direction of the planar vibrator vibrating due to the Coriolis force and the resonance frequency of the detection direction without performing troublesome trimming processing, and also to reduce the deviation of the detection direction. Thus, an excellent resonance element having high sensitivity and low noise can be obtained.

Further, the plane vibrator is constituted by providing a frame and a weight portion, and at least the weight portion having an interval in the X direction is provided on the side opposite to the plane of the plane vibrator in the Y direction. First vibrating body inclination correcting means are provided in both end edge regions, and the first vibrating body inclination correcting means is opposed to the frame, and is located at a position sandwiching the first vibrating body inclination correcting means with an interval in the X direction. In the apparatus provided with the vibrating body inclination correcting means, the resonance frequency of the planar vibrating body having the weight and the frame can be adjusted, and the inclination of the weight and the frame with respect to the surface of the fixed substrate can be individually corrected. can do.

Further, a weight is provided inside the frame via a connecting beam, and depending on the configuration of the connecting beam, the movement of the frame and the weight is made independent. For example, the plane vibrator vibrates in the X direction. When rotated about the Z axis, only the weight portion vibrates in the Y direction, and the frame body can hardly vibrate in the Y direction. In this way, the planar vibrator can be further stabilized. Excitation vibration can be performed in the vibration direction.

Further, in the case where the stress canceling means is provided, the stress canceling means cancels the tensile stress of the support beam caused by the electrostatic attraction to the planar vibrating body by the vibrating body inclination correcting means. Since the force can be applied directly or indirectly to the support beam, various problems caused by unnecessary tensile stress of the support beam can be reliably avoided. This makes it possible to provide an excellent resonance element having higher sensitivity and lower noise.

Further, a vertically movable electrode is provided on at least one of the front surface and the back surface of the weight portion, and a fixed opposed electrode is provided on the opposite side of the weight portion with an interval in the Y direction. The pair of the moving side electrode and the fixed counter electrode is configured as an angular velocity detecting electrode around the Z axis for detecting the vibration amplitude in the Y direction of the weight corresponding to the angular velocity change of rotation about the Z axis. According to the invention that functions as a moving-side electrode, an angular velocity detection electrode around the Z-axis formed by a set of a vertical moving-side electrode and a fixed counter electrode,
The angular velocity around the Z axis can be accurately detected.

[Brief description of the drawings]

FIG. 1 is a main part configuration diagram showing a first embodiment of a resonance element according to the present invention.

FIG. 2 is an explanatory diagram of a manufacturing process of the resonance element of the embodiment.

FIG. 3 is a main part configuration diagram showing a second embodiment of the resonance element according to the present invention.

FIG. 4 is an explanatory view showing a third preferred embodiment of a resonance element according to the present invention.

FIG. 5 is a main part configuration diagram showing another embodiment of the resonance element according to the present invention.

FIG. 6 is an explanatory diagram showing an example of the movement of the planar vibrator in the XY plane when the planar vibrator is vibrated in the X direction in the resonance element.

FIG. 7 is an explanatory diagram showing an example of a conventional resonance element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Weight part 3 Support beam 4 Exciter 10 Planar vibrator 23, 23A, 23B, 24, 24A, 24B Conductive layer 30 Vertically moving side electrode 31 Fixed counter electrode 40 Connecting beam 41, 41A, 41B, 42, 42A, 42B conductive layer

Claims (6)

[Claims] 1. A weight portion is arranged in a state of being floated on a fixed substrate having a substrate surface direction in the X, Z two-dimensional plane direction, and a planar vibrator provided with the weight portion is supported on the fixed substrate via a support beam. X
And an exciter that vibrates the planar vibrator in the X direction is provided.
On the opposite surface side with an interval in the Y direction orthogonal to the two-dimensional plane direction and at a distance from the plane of the planar vibrator, at least on both end edge regions of the planar vibrator with an interval in the X direction, A resonance element provided with a vibrating body inclination correcting means for adjusting the resonance frequency of the planar vibrating body by applying electrostatic attraction and correcting the inclination of the planar vibrating body with respect to the substrate surface direction of the fixed substrate; . 2. The planar vibrating body has a frame arranged in a state of being floated on a fixed substrate, and a weight connected to the inside of the frame via a connecting beam. A first vibrating body inclination correcting means is provided at least on both end edge regions of the weight portion, which are spaced from each other in the X direction, on a side facing the surface with a spacing in the Y direction. 2. The resonance element according to claim 1, wherein a second vibrating body inclination correcting means is provided at a position sandwiching the first vibrating body inclination correcting means with an interval in the X direction. 3. A stress canceling means for directly or indirectly applying a force to a support beam in a direction to cancel a tensile stress of the support beam caused by applying an electrostatic attractive force to the plane vibrator by the vibrating body inclination correcting means. The resonance element according to claim 1 or 2, wherein the resonance element is provided. 4. The stress canceling means is provided in such a form as to face the vibrating body inclination correcting means via the plane of the planar vibrator and to sandwich the planar vibrating body with an interval by the vibrating body inclination correcting means. 4. The structure according to claim 3, wherein an electrostatic attraction is applied to the body to cancel the tensile stress of the support beam caused by the electrostatic attraction applied to the planar vibrating body by the vibrating body inclination correcting means. Resonance element. 5. A vertical movement-side electrode is provided on at least one of the front surface and the back surface of the weight portion, and a fixed counter electrode is provided on a side opposite to the vertical movement-side electrode with an interval in the Y direction. The set of a movable side electrode and a fixed counter electrode is configured as a Z-axis angular velocity detection electrode for detecting a vibration amplitude in the Y direction of a weight corresponding to a change in angular velocity of rotation about the Z axis. The resonance element according to any one of claims 1 to 4. 6. The weight portion is formed of silicon or polysilicon, and the weight portion itself forms a vertical movement side electrode, and a fixed counter electrode is provided on an opposite side of the weight portion with an interval in the Y direction. A pair of the weight portion and the fixed counter electrode is configured as a Z-axis rotation angular velocity detection electrode for detecting a vibration amplitude in the Y direction of the weight portion corresponding to the angular velocity change of rotation about the Z axis. The resonant element according to any one of claims 1 to 4, wherein: