JP2017122679A - Gyro element and angular velocity sensor using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact angular velocity sensor which has a support method that would not have a low-order natural mode in a low-frequency region, and with which it is possible to prevent external vibration from propagating to an angular velocity detection element and support the angular velocity detection element without obstructing detection vibration, the angular velocity detection element, a support beam, and a stationary part being collectively fabricatable by MEMS machining.SOLUTION: Drive arm-side support beams 5 and detection arm-side support beams 6 are extended, with a base part 7 as a point of reference, so that an angle formed by the extension directions of the support beams 5 and an angle formed by the extension directions of the support beams 6 are 80 degrees or less, and are connected to the stationary parts 4, whereby it is possible to realize a gyro element 2 having a support method that would not have a low-order natural mode in a low-frequency region. Vibration occurring to an angular velocity detection element can be suppressed by the support beams, and it is possible to prevent external vibration from propagating to the angular velocity detection element.SELECTED DRAWING: Figure 1

Description

The present invention relates to a gyro element represented by a piezoelectric vibration type yaw rate sensor.

In recent years, many devices that detect minute vibrations using piezoelectric elements have been utilized. As one of them, for example, by detecting very weak vibration and displacement caused by Coriolis force generated when rotation is applied to the vibrating mass body through the piezoelectric element, Examples thereof include a gyro element such as a piezoelectric vibration type yaw rate sensor or a gyro sensor that can detect and measure a rotational operation, that is, a rotational angular velocity. Among them, as a long-life, low-cost, small and lightweight gyro element, it is equipped with an angular velocity detection element having a plurality of vibrating arms facing each other across the base, and one vibrating arm, that is, the driving arm is driven in a plane. An H-type gyro element that detects vibration / displacement generated in the direction orthogonal to the driving direction by Coriolis force by the other vibrating arm, that is, a detection arm has been proposed or put into practical use. When the drive arm is driven at a frequency close to the resonance frequency of the detection vibration mode selected for detecting the Coriolis force, both the drive arm and the detection arm are likely to swing with respect to the drive vibration, and a larger detection signal is generated. It has been confirmed from experience that the sensitivity of the gyro element itself can be improved. In addition, since the H-shaped angular velocity detecting element having an H-shaped shape has two detection vibration modes, it is a shape suitable for stably realizing high sensitivity.

In order to realize an extremely small and highly sensitive gyro element, it is necessary to obtain a large displacement using the resonance frequency of each vibrating arm. In addition, for example, a gyro element used for detecting the attitude behavior of an automobile is required to have high performance in terms of vibration resistance and impact resistance.

The angular velocity detecting element vibrates in a complicated manner by acting at least two orthogonal vibration modes of an excitation vibration for obtaining a Coriolis force and a detection vibration for detecting the Coriolis force. It is desirable that the vibrations of these angular velocity detection elements are originally vibrated in a closed system. However, in actual angular velocity detection elements, there are leakage vibrations caused by machining asymmetry, etc., and vibration mode modes used for excitation and detection. Depending on the shape, it is unavoidable that the vibration of the angular velocity detection element leaks to the outside of the element, or the vibration outside the element is transmitted to the angular velocity detection element. If the material is supported by a low-rigidity material such as silicone rubber in order to reduce external vibrations, the vibration-resistant characteristics against the unnecessary vibration applied from the outside and the shock-resistant performance are deteriorated. When the gyro element is used for detecting the attitude behavior of an automobile, vibration applied from the outside exists in a frequency range of several Hz to several tens kHz. When the gyro element has a resonance mode in these frequency ranges, unnecessary vibration occurs in the angular velocity detection element due to external vibration, leading to a decrease in accuracy. For example, if an external vibration having a frequency close to the resonance point of the detection vibration mode is applied to the angular velocity detection element, the angular velocity detection element vibrates in the detection mode even if there is no angular velocity, and the angular velocity is erroneously detected. Therefore, it is necessary that the element itself does not have a resonance point in the vicinity of a frequency range that will be generated outside. However, depending on the method of supporting the angular velocity detecting element, a resonance point is provided in this frequency range. For example, it has been found that a low-order eigenmode is low in a structure including a large mass supported by a cantilever having a low elastic modulus. However, if the support structure is simply supported by a thick and thick beam to increase the elastic modulus of the support structure, the drive vibration mode and the detection vibration mode of the angular velocity detection element are suppressed by the support structure, and the vibration amplitude is reduced. As a result, the characteristics of the angular velocity detecting element are deteriorated. In this case, it is also easily affected by external vibration. Even if the method of supporting the angular velocity detection element is devised to prevent deterioration of sensor characteristics due to external vibration, problems such as an increase in the number of processes and an increase in cost occur when the structure is complicated. Therefore, a method for easily realizing a support method that is resistant to external vibration is desired.

Patent Document 1 shows an example of a conventional H-type gyro element. There is an H-shaped vibrating arm, and there are a driving arm for exciting and a detecting arm for detecting a vibration state when vibrating. There is a support beam that supports the vibrating arm, and four vibrating arms including two drive arms and two detection arms are provided in an H shape so as to protrude from the support beam. The connecting piece fixes and supports the support beam, and has strain detection means for detecting the degree of strain of the support beam when the vibrating arm vibrates.

The operation of the conventional H-type gyro element configured as described above will be described. First, when the driving arm for exciting one side is vibrated along the X axis which is an axis perpendicular to the longitudinal direction of the vibrating arm, the detection arm for detecting the vibration state is orthogonal to the X axis. A vibration state when vibrating along the Z-axis direction is detected. At this time, strain detection means provided on the support beam detects the degree of strain of the support beam. Patent Document 1 discloses a technique in which the strain detection means is disposed on both sides of the protruding portion of the connecting piece in the support beam.

Patent Document 2 shows an example of an angular velocity sensor of a package on which a tuning fork vibrator is mounted. The package is mounted with a tuning fork vibrator that is attached directly or via an electronic component and some member. When the tuning fork vibrator vibrates, it is transmitted to the package, and vibration leakage to the outside may occur. In particular, it has been pointed out that when a lightweight material such as ceramics is used as a package material, there is a problem that the characteristics of the tuning fork vibrator are not stable due to vibration leakage. In Patent Document 2, as a means for solving this problem, inertia when a tuning fork vibrator is arranged in a package so that the width direction of the tuning fork vibrator is in the long side direction of the package and the tuning fork vibrator is held in the package is disclosed. A technique for increasing the size is disclosed.

Patent Document 3 shows an example of an angular velocity sensor that includes a support portion on which a tuning fork vibrator is mounted, and a vibration isolation portion that connects the support portion and the mounting portion. In an angular velocity sensor having a vibrator, the vibration of the vibrator leaks to the outside through other components. For this reason, when the angular velocity sensor is mounted on a system or the like, the vibration state may change, and the characteristics of the vibrator may change. In Patent Document 3, when the tuning fork vibrator vibrates, the vibration of the vibrator is reduced by the moment of inertia of the weight of the support portion. Furthermore, a method for preventing external vibration leakage and reducing the influence of external vibration on the vibrator is disclosed by holding the support portion with a low-rigidity member such as silicone rubber called a vibration isolation portion.

JP-A-8-334332 JP 2007-71672 A JP 2008-8634 A

However, in the conventional configuration of Patent Document 1, the support arm passes between the drive arm and the detection arm with the connecting portion as a base point, and the support beam is longer than the drive arm and the detection arm. As a result, the frequency of the low-order eigenmode of the element decreases, resulting in a structure that is vulnerable to external vibration. In addition, since the support beam passes between the drive arm and the detection arm, the support beam exists in the vibration direction of the vibration arm, which increases the size of the vibration arm in the vibration direction. The increase in size limits the miniaturization of the element, and hinders space saving and cost reduction.

In the conventional configuration of Patent Document 2, the inertia is increased by aligning the width direction of the vibrator with the long side direction of the package, and the vibration of the vibrator is hardly leaked to the outside. It has a problem that the effect is limited because it is transmitted to. In addition, since the direction of detection is determined by the direction of the element, there is a problem that the restriction due to the arrangement of the angular velocity detection element occurs.

The conventional configuration of Patent Document 3 has a problem that the frequency of the low-order eigenmode is lowered because the heavy support portion on which the vibrator is placed is held by the silicone rubber member. Fixing with silicone rubber makes it difficult to ensure the stability of assembly dimensions such as height, and this places a burden on manufacturing management. It is easy to cause a volume change with respect to the ambient temperature change, and to easily change the characteristic of the angular velocity sensor. Furthermore, since silicone rubber has low rigidity, there is a concern that vibration applied from the outside may adversely affect the angular velocity detecting element.

The present invention has been made in consideration of the above points, and an object of the present invention is to realize a gyro element and an angular velocity sensor having a support method that does not have a low-order eigenmode in a low frequency range.

The detection element is fixed via a detection element having a base, a pair of drive arms, a pair of detection arms, a pair of drive arm side support beams, and a pair of detection arm side support beams. A gyro element having a fixed portion,
The pair of drive arms and the pair of detection arms extend in the longitudinal direction of the detection element in directions opposite to each other with the base as a base point,
The base portion is extended from the base point so that the angle formed by the extending direction of the pair of driving arm side support beams and the angle formed by the extending direction of the pair of detection arm side support beams are 80 degrees or less. It is a gyro element characterized by having.

In this way, the base arm is extended to the base point so that the angle formed by the extending direction of the drive arm side support beam and the angle formed by the extending direction of the detection arm side support beam is 80 degrees or less, and the fixing is performed. By connecting to the unit, it is possible to realize a gyro element having a support method that does not have a low-order eigenmode in a low frequency range.

  In the present invention, the detection element, the pair of drive arm side support beams, and the pair of detection arm side support beams are parallel to a longitudinal direction in which the pair of drive arms and the pair of detection arms extend. The gyro element according to claim 1, wherein the gyro element is line-symmetric with respect to a central axis of the detection element.

With such a configuration, a gyro element having a support method for preventing vibration from leaking to the outside can be realized in a small size.

3. The gyro element according to claim 1, wherein a width in a direction perpendicular to an extending direction of the driving arm side support beam and the detection arm side support beam is 100 μm or less.

With such a configuration, the angular velocity detection element can be supported without hindering the detection vibration of the angular velocity detection element by holding the angular velocity detection element via a thin and long support beam.

According to the present invention, the detection element, the pair of driving arm side support beams, the pair of detection arm side support beams, and the fixing portion are formed by processing a semiconductor substrate by a semiconductor lithography technique. It is good also as a gyro element in any one of Claim 1 to 3 characterized by the above-mentioned.

With such a configuration, the angular velocity detection element, the support beam, and the fixed portion can be manufactured together by MEMS processing, and the sensor can be easily manufactured.

  Moreover, this invention is an angular velocity sensor provided with the gyro element in any one of Claim 1 to 4, and the package which fixes the said gyro element, Comprising: The said detection element of the said gyro element is the said fixing | fixed part. An angular velocity sensor may be fixed to the package.

With such a configuration, an angular velocity sensor having a gyro element that does not have a low-order eigenmode in a low frequency range can be realized.

An angular velocity that has a support method that does not have a low-order eigenmode in a low frequency range, can prevent external vibration from being transmitted to the angular velocity detection element, and can support the angular velocity detection element without interfering with the detected vibration. It is possible to provide a small-sized gyro element in which the detection element, the support beam, and the fixed portion can be collectively manufactured by MEMS processing.

It is a perspective view which shows the angular velocity sensor of 1st Embodiment. It is a top view which shows the gyro element of 1st Embodiment. When the angle formed by the extending direction of the pair of drive arm side support beams and the angle formed by the extending direction of the pair of detection arm side support beams are varied as parameters, which of the low-order resonance frequencies of the angular velocity detecting element is determined? It is a figure which shows the simulation value which investigated how it changed. It is a figure showing the simulation value which investigated how the sensitivity of the angular velocity detection element changes when the width in the direction perpendicular to the extending direction of the drive arm side support beam and the detection arm side support beam is changed as a parameter. is there. It is a figure which shows the simulation value which investigated how the low-order resonance frequency of an angular velocity detection element changed, when changing the distance between a drive arm side support beam and a detection arm side support beam as a parameter. It is an exploded view which shows the angular velocity sensor of 2nd Embodiment. It is sectional drawing which shows the modification of the angular velocity sensor of 2nd Embodiment.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In addition, this invention is not limited to the following embodiment. The constituent elements described below include those that can be easily assumed by those skilled in the art and those that are substantially the same. Furthermore, the constituent elements described below can be appropriately combined. Embodiments will be described with reference to the drawings. In these drawings, electrodes and wiring portions are omitted for easy understanding of the shape. Of course, these are necessary for actual sensors.

(Embodiment 1)
FIG. 1 is a perspective view of a piezoelectric vibration type angular velocity sensor 1 according to the first embodiment. In FIG. 1, the angular velocity sensor 1 includes a pair of drive arms 8 and a pair of detection arms 9. A fixing portion 4 for fixing the angular velocity detection element 3 via the element 3, a pair of driving arm side support beams 5, and a pair of detection arm side support beams 6; a package for holding the gyro element 2; It has. Although not shown, the angular velocity sensor 1 is one component that constitutes a system for detecting the angular velocity. In many cases, the angular velocity sensor 1 is used by being mounted on a circuit board together with surrounding circuit components. In the embodiment, this circuit board is referred to as an external circuit board.

Examples of the shape of the angular velocity detecting element 3 that detects the angular velocity by the Coriolis force include a tuning fork type having a substantially U shape and a substantially H shape. In particular, the H-shaped angular velocity detecting element having an H shape is a shape suitable for realizing high sensitivity and low noise. The drive arm side support beam 5 and the detection arm side support beam 6 are optimized so as not to hinder the movement of the vibrating arm of the angular velocity detection element 3.

In FIG. 1, the angular velocity detecting element 3 includes a base portion 7 located at the center, a pair of driving arms 8 extending in a predetermined direction across the base portion 7, and a pair of driving arms 8 extending in the opposite direction to the driving arms 8. A detection arm 9 is provided. The angular velocity detection element 3 including the base 7, the drive arm 8, and the detection arm 9 is made of a common material, for example, Si or quartz, and is integrated with a wafer patterning process (semiconductor process) made of general Si or the like. It can be formed in a lump.

The drive arm 8 and the detection arm 9 are vibration arms, and the drive arm 8 is provided with a piezoelectric element that enables vibration, although not shown in order to make the shape easy to understand. An electric signal is input to and output from the piezoelectric element, and the piezoelectric element can vibrate. As shown in FIG. 1, the holding direction of the angular velocity detecting element 3 is selected so that the longitudinal direction of the angular velocity detecting element 3 matches the direction of the central axis 10 shown in FIG. The central axis 10 is the center of rotation of the angular velocity detection element 3 and the fixed portion 4, the drive arm side support beam 5, the detection arm side support beam 6, that is, the gyro element 2, and a pair of drive arms 8 and a pair. This is an axis that is parallel to the longitudinal direction in which the detection arm 9 extends and that makes the angular velocity detection element 3 line-symmetric with respect to the longitudinal direction.

The angular velocity sensor 1 operates in a drive vibration mode in which the drive arm 8 is initially excited and a detection vibration mode in which the detection arm 9 detects the angular velocity orthogonal to the direction of the drive vibration. The H-type angular velocity detection element has two detection vibration modes. That is, there are a first detection vibration mode in which the drive arm 8 and the detection arm 9 vibrate in opposite phases, and a second detection vibration mode in which the drive arm 8 and the detection arm 9 vibrate in the same phase. By having these two detection vibration modes, the sensitivity is stable, and high sensitivity is realized as compared with the case of one detection vibration mode. The drive arm 8 and the detection arm 9 are coupled to each other via the base portion 7, and the base portion is coupled to the fixed portion 4 via the support beams 5 and 6. It is desirable that the base is small so that the vibration by the two detection vibration modes is not hindered, and that the support portion flexibly supports the base. The drive arm side support beam 5 and the detection arm side support beam 6 have a shape with a small width and a long length in the longitudinal direction. By doing so, the angular velocity detection element 3 can be fixed so as not to disturb the two detection vibration modes.

In addition, by constructing the support beam so that it spreads radially outward from the base, it is possible to translate in the thickness direction, or to cause the drive arm and the detection arm to vibrate in opposite phases in the thickness direction. The frequency of the mode is not lowered.

In FIG. 1, the angular velocity detecting element 1 is made of a semiconductor material such as Si. For example, the support beam can be a prismatic shape having a rectangular cross section, and the prism shape is particularly clear in the thickness direction, that is, in the Z-axis direction, and in the width direction, that is, in the X-axis direction. It is preferable because it can be divided into two types. As an example, from the point of impact resistance, if you want to have a certain degree of freedom in the width direction while maintaining rigidity in the thickness direction, you can configure a larger size in the thickness direction and a smaller size in the width direction. .

  When the angle between the extension direction of the pair of drive arm side support beams and the angle between the extension direction of the pair of detection arm side support beams are varied as parameters in FIG. The simulation value which investigated how the frequency of a mode changes is shown. Here, an angle 100 formed by the extending direction of the pair of driving arm side support beams and an angle 200 formed by the extending direction of the pair of detection arm side support beams indicate the angles shown in FIG.

When the angle formed by the extending direction of the pair of driving arm side support beams and the angle formed by the extending direction of the pair of detection arm side support beams are small, the frequency of the low-order eigenmode of the angular velocity detecting element increases. There was a trend. This is considered to be because the shape of the pair of driving arms and the pair of detection arms is such that the low-order eigenmodes that vibrate in opposite phases in the thickness direction are suppressed. In the eigenmode in which the pair of drive arms and the pair of detection arms vibrate in the opposite phases in the thickness direction, the secondary secondary moments in the YZ plane of the drive arm side support beam and the detection arm side support beam are The larger the frequency, the larger the frequency of the eigenmode. In the YZ plane, the cross-sectional secondary pole moments of the drive arm side support beam and the detection arm side support beam increase in proportion to the size of the dimension in the Y direction. A configuration in which the driving arm side support beam and the detection arm side support beam spread widely on both sides in the longitudinal direction of the element is effective in improving vibration resistance.

The characteristic required for the angular velocity detecting element is vibration resistance, and it is necessary not to have a resonance frequency in a low frequency band. In general, vibration resistance performance of a required frequency is required to have no resonance frequency below 20 kHz. From the simulation results, when the angle formed by the extending direction of the pair of driving arm side support beams and the angle formed by the extending direction of the pair of detection arm side support beams are approximately 80 degrees or less, the low-order resonance frequency Is 20 kHz or more, and it is clear from this result that this embodiment is effective in improving vibration resistance. When the angle is 80 degrees or more, the resonance frequency tends to decrease greatly, and as shown in the simulation results, the angle formed by the support beam is 80 degrees or less, more preferably a smaller angle, as the configuration of the angular velocity detecting element.

However, the designable angle is limited due to restrictions on the element shape. In the shape of the embodiment, the drive arm and the detection arm are extended in the longitudinal direction of the angular velocity detection element in opposite directions with the base as the base point, and the drive arm exhibits vibrations that excite Coriolis force on the gyro element plane. This occurs in the in-plane direction, and this vibration amplitude limits the possible beam angle. In order to prevent the drive arm and the support beam from interfering with each other, it is desirable to configure the element and the support beam with a margin of 50 μm or more with respect to the expected vibration amplitude of the arm.

A tuning fork-type or H-type gyro element has a configuration of a base and a vibrating arm extending from the base, and the vibration amplitude of the vibrating arm increases as the part is further away from the base. When the angular velocity detection element is held by the support beam extending from the base as in the present embodiment, the support beam extends in the direction away from the vibrating arm as it extends to the fixed portion, and therefore the movable arm is out of the movable range and Since the support beam is configured to reduce the occupied area of the gyro element, this embodiment is effective from the viewpoint of downsizing the gyro element.

  FIG. 4 shows simulation values for examining how the sensitivity of the angular velocity detection element changes when the width in the direction perpendicular to the extending direction of the drive arm side support beam and the detection arm side support beam is changed as a parameter. Show. Here, the width 300 in the direction perpendicular to the extending direction of the drive arm side support beam and the width 400 in the direction perpendicular to the extending direction of the detection arm side support beam indicate the dimensions shown in FIG.

When the width of the supporting beam in the direction perpendicular to the extending direction was increased, the sensitivity tended to decrease. This is considered to be because the rigidity of the beam is increased by increasing the width of the support beam, and the detection vibration mode is suppressed. The narrower the width in the direction perpendicular to the extending direction of the support beam, the higher the sensitivity can be expected because the detection vibration mode of the angular velocity detection element is not suppressed. In view of the relationship between the rigidity and the low-order resonance frequency, it is necessary to appropriately optimize the structure in accordance with the usage conditions such as the environment and required performance required for the element. For example, the sensitivity to the angular velocity is generally desirably 1 μV / ° / sec or more, and at this time, the width in the direction perpendicular to the extending direction of the support beam is desirably 100 μm or less.

  FIG. 5 shows simulation values for examining how the low-order resonance frequency of the angular velocity detection element changes when the distance between the drive arm side support beam and the detection arm side support beam is varied as a parameter. Here, the distance 500 between the drive arm side support beam and the detection arm side support beam indicates the dimension shown in FIG.

Increasing the length between the drive arm side support beam and the detection arm side support beam increases the frequency of the low-order eigenmode. This is because the four support beams have a shape that suppresses a low-order mode in which a pair of drive arms and a pair of detection arms vibrate in opposite phases in the thickness direction. A large length between the side support beam and the detection arm side support beam is desired from the viewpoint of vibration resistance. However, if the length between the drive arm side support beam and the detection arm side support beam is large, the gyro element will be reduced in size, so the shape design according to the usage conditions such as the required size and required performance of the element It is necessary to do. For example, the width in the direction perpendicular to the extending direction of the support beam is 100 μm, the angle between the beams is 80 degrees, and the length between the drive arm side support beam and the detection arm side support beam is 0 mm, that is, the drive arm side support If the beam and the detection arm side support beam are arranged in contact with each other at the base so as not to cross each other, and the resonance frequency of the low-order eigenmode is 20 kHz or more at this time, the drive arm side support beam is considered for miniaturization of the element. It is desirable to avoid increasing the length between the support arm and the detection arm side support beam.

(Embodiment 2)
FIG. 6 is an exploded view of the piezoelectric vibration type angular velocity sensor according to the second embodiment. The first cap layer 1, the first spacer layer 2, the gyro element 3, the second spacer layer 4, and the second cap layer 5 are illustrated. , And the gyro element 3 can be packaged. The cap layer 1 and the spacer layer 2 or the cap layer 5 and the spacer layer 4 may be a single structure.

The cap layer, the spacer layer, and the gyro element can be integrally manufactured by the same process by micromachining technology. Since high mechanical performance is required as a characteristic required for the package, the cap layer 1 and the spacer layer 2 may be made of a semiconductor such as Si or SiO2, a metal such as stainless steel, or a dielectric material such as ceramics. It is also conceivable to form a structure using a multilayer substrate such as an SOI substrate. Further, in order to prevent deformation such as warping due to stress, the linear expansion coefficient of each layer is desirably the same or close to each other.

FIG. 7 is a cross-sectional view of a modification of the piezoelectric vibration type angular velocity sensor according to the second embodiment. The device layer 21 includes a gyro element, the spacer layer 22, the cap layer 23, and the cap layer 24 includes a spacer layer. This is an example of an angular velocity sensor including a drive mechanism 25 that drives a gyro element. The drive mechanism 25 may be a piezoelectric element, for example.

The shape of the embodiment can be manufactured by a micromachining technique. Since the vibrating arm of the gyro element vibrates in a direction perpendicular to the gyro element plane, it is necessary to configure the gyro element so that the vibrating arm and the cap layer do not interfere with each other. It is desirable that the surface of the cap layer facing the device layer is separated from the vibration arm of the device layer by an expected vibration amplitude of 5 μm or more. It is also possible to easily adjust the inside of the depletion composed of the device layer 1, the spacer layer 2, the cap layer 3, and the cap layer 4 including the spacer layer to a necessary atmosphere. Since the atmosphere state when the cap layer 4 including the spacer layer, the cap layer 3, and the spacer layer 2 are bonded to the device layer 1 is maintained inside, the inside of the depletion can be adjusted to a desired atmosphere.

From the viewpoint of handling, an angular velocity sensor composed of a cap layer, a spacer layer, and a device layer is desirable. In recent years, along with high integration for the purpose of reducing the size and cost of MEMS devices, the wafer size has been increased. When handling large-diameter wafers during processing, there is a risk of damage due to slight stress, external force, dead weight, etc. Even if the device requires a thin substrate, it should not be damaged until it is processed into a final product. Transporting wafers is a difficult task. Even if it is fixed with a holding member such as a resist or a handling wafer and the strength is increased, there may be a problem that a defect occurs in the film forming or peeling process. A multilayer substrate such as an SOI substrate is structurally strong because it includes a layer called a handling layer. Further, since the handling layer is also used as a package member as it is, there is no need for peeling, and there is no increase in the process or reduction in yield. .

In order to reduce the size and increase the accuracy of the element, it is desirable that the angular velocity sensor and the sensor control circuit are adjacent to each other. The angular velocity sensor is connected to the control circuit to detect the vibration and angular velocity of the driving arm. However, the longer the lead wire for connecting the angular velocity sensor and the control circuit, the more noise is generated and the measurement accuracy is lowered. It is desirable to arrange the elements directly above the circuit or to arrange them adjacent to each other in a plane.

The angular velocity sensor according to the present invention can be used for applications that detect angular velocities caused by rotation of substances such as automobiles, car navigation, camera shake prevention cameras, and industrial equipment.

DESCRIPTION OF SYMBOLS 1 Angular velocity sensor 2, 13, 21 Gyro element 3 Angular velocity detection element 4 Fixed part 5 Drive arm side support beam 6 Detection arm side support beam 7 Base 8 Drive arm 9 Detection arm 10 Center axis of rotation 11, 23 First cap layer 12 , 22 First spacer layer 14 Second spacer layer 15, 24 Second cap layer 25 Drive mechanism 100 Angle formed by extending direction of one pair of driving arm side support beams 200 Formed by extending direction of one pair of detection arm side support beams Angle 300 Width in the direction perpendicular to the extension direction of the drive arm side support beam 400 Width in the direction perpendicular to the extension direction of the detection arm side support beam 500 Distance between the drive arm side support beam and the detection arm side support beam

Claims (5)

The detection element is fixed via a detection element having a base, a pair of drive arms, a pair of detection arms, a pair of drive arm side support beams, and a pair of detection arm side support beams. A gyro element having a fixed portion,
The pair of drive arms and the pair of detection arms extend in the longitudinal direction of the detection element in directions opposite to each other with the base as a base point,
The base portion is extended from the base point so that the angle formed by the extending direction of the pair of driving arm side support beams and the angle formed by the extending direction of the pair of detection arm side support beams are 80 degrees or less. A gyro element characterized by comprising:   The detection element, the pair of drive arm side support beams, and the pair of detection arm side support beams are parallel to a longitudinal direction in which the pair of drive arms and the pair of detection arms extend. The gyro element according to claim 1, wherein the gyro element is line symmetric with respect to a central axis of the element.   3. The gyro element according to claim 1, wherein a width in a direction perpendicular to an extending direction of the drive arm side support beam and the detection arm side support beam is 100 μm or less.   The detection element, the pair of driving arm side support beams, the pair of detection arm side support beams, and the fixing portion are formed by processing a semiconductor substrate by a semiconductor lithography technique. The gyro element according to any one of 1 to 3.   An angular velocity sensor comprising the gyro element according to claim 1 and a package for fixing the gyro element, wherein the detection element of the gyro element is fixed to the package by the fixing portion. An angular velocity sensor.

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