JP2014157162A - Inertial force sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect angular velocity in a plurality of axial directions with one inertial force sensor while preventing false detection due to shock and vibration applied from the outside.SOLUTION: An inertial force sensor comprises: an inertial force detecting element 1 comprising weight sections 7, a connecting section composed of a first arm 2 and a second arm 3 which have flexibility, support the weight sections 7, and are formed in the same plane, a frame body 6 for holding the weight sections 7 through the connecting section, and sensing electrodes 10 for detecting angular velocity around at least two axes of rotation different in direction; supporting bodies 12 which have flexibility, support the inertial force detecting element 1 and have a board-like shape; and a housing body 11 for housing the inertial force detecting element 1 through the supporting bodies 12. The supporting bodies 12 comprise a bending section 13 in a thickness direction.

Description

  The present invention relates to an inertial force sensor capable of detecting angular velocities used in various electronic devices such as attitude control and navigation of moving bodies such as aircraft, automobiles, robots, ships, and vehicles.

  As an inertial force sensor, an angular velocity sensor, an acceleration sensor, a sensor capable of detecting both angular velocity and acceleration, and the like are known.

  Regarding acceleration, when trying to detect the acceleration of each of the X-axis, Y-axis, and Z-axis that are orthogonal to each other, an acceleration sensor that detects the acceleration in the X-axis direction and the acceleration in the Y-axis direction are detected. By using a total of three acceleration sensors, i.e., an acceleration sensor that detects acceleration in the Z-axis direction and an acceleration sensor that detects acceleration in the Z-axis direction, accelerations in the three-axis directions of the X axis, the Y axis, and the Z axis can be detected.

  As for angular velocities, a total of three angular velocity sensors are used: an angular velocity sensor that detects an angular velocity around the X axis, an angular velocity sensor that detects an angular velocity around the Y axis, and an angular velocity sensor that detects an angular velocity around the Z axis. The angular velocity around each axis can be detected.

  However, the use of a plurality of sensors in order to detect acceleration in a plurality of axes or angular velocities around the plurality of axes has a problem such as an increase in overall size.

  On the other hand, a technique for detecting acceleration in a plurality of axes and angular velocities around the plurality of axes by one inertial force sensor is known. Among such technologies, a mass part having a mass sufficient to detect inertial force, a fixing part for holding and fixing the mass part, and a connection for connecting the fixing part and the mass part The connection part is flexible, and the inertial force is detected using deformation of the connection part due to the action of inertial force or the change of the position of the mass part in the inertial force detection element. Is known (for example, Patent Document 1).

  Moreover, as an anti-vibration structure of an inertial force sensor capable of detecting an angular velocity, a structure using an elastic body that is easily bent in a direction in which Coriolis force is generated is known (for example, Patent Document 2).

JP 2008-046058 A International Publication No. 2006/132277 Pamphlet

  However, the conventional inertial force sensor has a problem in terms of anti-vibration measures when attempting to detect angular velocities around a plurality of axes with a single inertial force sensor.

  That is, for example, when detecting the angular velocity around the Z axis, if the mass part is driven and vibrated in the X axis direction, the Coriolis force due to the angular velocity around the Z axis acts in the Y axis direction. The angular velocity around the Z-axis can be detected from the bending of the connecting part. However, if the mass part is subjected to inertial force due to external impact or vibration, the connecting part is bent in the Y-axis direction. The possibility of is generated. For this reason, it is necessary to provide an anti-vibration structure against external impacts and vibrations. In this case, a vibration-proof structure that reduces vibration in the Y-axis direction is provided. What is easy to bend in the Y-axis direction may be used. However, the conventional anti-vibration structure of the inertial force sensor does not have a plurality of anti-vibration functions in the axial direction.

  SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems, and an object of the present invention is to detect a plurality of angular velocities in a plurality of axial directions with a single inertial force sensor while preventing erroneous detection due to external impact and vibration.

  In order to achieve the above object, the present invention has the following configuration.

  An example of the inertial force sensor according to the present invention includes a mass portion, a connecting portion that has flexibility and supports the mass portion, has a predetermined thickness, and is formed on the same plane, and the mass via the connecting portion. An inertial force detection element having a fixed part for holding the part and a detection part for detecting an angular velocity having at least two different directions of rotation axes, and a plate that has flexibility and supports the inertial force detection element And a storage body that holds the inertial force detection element via the support, and the support has a bending portion in the thickness direction.

  With this configuration, in the example of the inertial force sensor according to the present invention, since the support is provided with a bent portion, the spring constant of the support is low, the natural frequency is low, and external shock and vibration are transmitted. The detection effect can be reduced and the detection performance is improved.

  An example of the inertial force sensor according to the present invention includes a configuration in which the orientation in the width direction of the support at the bent portion is parallel to the plane on which the connecting member is formed. With this configuration, an example of the inertial force sensor according to the present invention can reduce the spring constant with respect to a direction perpendicular to the direction of the width direction of the support in the bent portion, and can reduce the natural frequency in this direction. The transmission of impact and vibration from the outside in this direction can be reduced, and the detection performance is improved.

  An example of the inertial force sensor according to the present invention is the case where, particularly when the plane on which the connecting portion is formed is an XY plane and the direction perpendicular thereto is the Z axis, the inertial force detection element in the support body is stored in the housing. The length of the support body in the Z-axis direction from the inertial force detection element to the storage body is longer than the length in the XY plane direction to the body. An example of the inertial force sensor according to the present invention can reduce the natural frequency in the XY plane direction by this configuration, and in particular, the angular velocity detection that generates the Coriolis force in the direction parallel to the XY plane. , The transmission of shock and vibration from the outside can be reduced, and the detection performance is improved.

  An example of the inertial force sensor according to the present invention is such that when the plane on which the connecting portion is formed is an XY plane, a plurality of the supports are formed, and the inertial force detection in the support is performed. There is a configuration in which there are two non-parallel directions in the XY plane direction from the element to the storage body. An example of the inertial force sensor according to the present invention has the effect of improving the balance because the spring constants in the X-axis direction and the Y-axis direction of the connecting portion can be made the same by this configuration.

  An example of the inertial force sensor according to the present invention is the case where, particularly when the plane on which the connecting portion is formed is an XY plane and the direction perpendicular thereto is the Z axis, the inertial force detection element in the support body is stored in the housing. The length of the support body in the XY plane direction from the inertial force detection element to the storage body is longer than the length in the Z-axis direction to the body. An example of the inertial force sensor according to the present invention can reduce the natural frequency in the Z-axis direction by this configuration, and in particular, an angular velocity detection that generates a Coriolis force in a direction parallel to the Z-axis. , The transmission of shock and vibration from the outside can be reduced, and the detection performance is improved.

  The present invention includes a mass part, a connecting part that has flexibility and supports the mass part, has a predetermined thickness and is formed on the same plane, and a fixing part that holds the mass part via the connecting part. , An inertial force detection element including a detection unit for detecting an angular velocity having at least two different directions of rotation axes, a plate-like support body that has flexibility and supports the inertial force detection element, A storage body for holding the inertial force detection element via a support body is provided, and the support body has a bending portion in the thickness direction, and this configuration can prevent erroneous detection due to external impact and vibration. It has the effect of being able to.

The perspective view of the inertial force detection element of the inertial force sensor in one embodiment of this invention Driving vibration state diagram of the inertial force detection element Strain vibration state diagram of the inertial force detection element due to angular velocity around the Z axis Strain vibration state diagram of the inertial force detection element due to angular velocity around the Y axis Front sectional view of inertial force sensor according to the present invention Top view of the inertial force sensor The figure which shows the manufacturing method of the inertial force sensor in one embodiment of this invention The figure which shows the manufacturing method of the inertial force sensor in one embodiment of this invention The figure which shows the manufacturing method of the inertial force sensor in one embodiment of this invention The figure which shows the manufacturing method of the inertial force sensor in one embodiment of this invention The figure which shows the manufacturing method of the inertial force sensor in one embodiment of this invention The figure which shows the manufacturing method of the inertial force sensor in one embodiment of this invention The figure which shows the manufacturing method of the inertial force sensor in one embodiment of this invention The figure which shows the manufacturing method of the inertial force sensor in one embodiment of this invention The figure which shows the manufacturing method of the inertial force sensor in one embodiment of this invention Front sectional view of the first variation of the inertial force sensor in one embodiment of the present invention Front sectional view of the second variation of the inertial force sensor in one embodiment of the present invention The top view of the 3rd variation of the inertial force sensor in one embodiment of this invention The perspective view of the 4th variation of the inertial force sensor in one embodiment of this invention The top view of the 5th variation of the inertial force sensor in one embodiment of this invention Front sectional view of the fifth variation of the inertial force sensor

  Hereinafter, the invention according to claims 1 to 5 of the present invention will be described using embodiments.

  First, the inertial force detection element 1 will be described with reference to FIGS.

  1 is a perspective view of an inertial force detection element of an inertial force sensor according to an embodiment of the present invention, FIG. 2 is a driving vibration state diagram of the inertial force detection element, and FIG. 3 is the same inertia caused by an angular velocity around the Z axis. FIG. 4 is a strain vibration state diagram of the inertial force detection element due to the angular velocity around the Y axis.

  An inertial force sensor according to an embodiment of the present invention includes an inertial force detection element 1 having a function of detecting an angular velocity. In this inertial force detection element 1, two first arms 2 and two second arms 3 are connected to one of the two first arms 2. The second arm 3 is connected to the first arm 2 in a substantially perpendicular direction. One end of the two first arms 2 is supported by the third arm 4, and the other end of the two first arms 2 is connected to a frame body 6 (fixed portion) having a slit 5.

  The second arm 3 extends from the first arm 2 in a right angle direction, and further extends in a right angle direction, that is, a direction parallel to the first arm 2, and thereafter, is connected to the right arm direction, that is, the first arm 2. The bent portion 7 is bent in a U shape so as to extend in a direction parallel to the extending direction of the second arm 3, and the weight portion 7 (mass portion) is connected to the tip of the bent second arm 3. ing. The first arm 2 and the third arm 4 are arranged on substantially the same straight line, and the first arm 2 and the second arm 3 are arranged symmetrically with respect to the center of the inertial force detection element 1. The first arm 2 and the second arm 3 constitute a connecting portion.

  When the first arm 2 is arranged in the X-axis direction and the second arm 3 is arranged in the Y-axis direction on the X-axis, Y-axis, and Z-axis orthogonal to each other, the second arms facing each other on the positive side of the Y-axis The first drive electrode 8 that drives and vibrates the weight portion 7 on the positive side of the Y axis is disposed on one side of the Y axis 3, and the negative electrode of the Y axis is disposed on one of the second arms 3 that face each other on the negative side of the Y axis. A second drive electrode 9 for driving and vibrating the weight portion 7 on the side is arranged. In addition, each of the second arms 3 is provided with a sensing electrode 10 (detection unit) that senses the distortion of the second arm 3. The first and second drive electrodes 8, 9 and the sensing electrode 10 are formed of an upper electrode and a lower electrode with a piezoelectric layer interposed. The first arm 2 and the second arm 3 are arranged in a plane parallel to the XY plane.

  Next, detection of angular velocity will be described.

  FIG. 2 is a drive vibration state diagram of the inertial force detection element 1.

  When the first arm 2 is arranged in the X-axis direction and the second arm 3 is arranged in the Y-axis direction on the X, Y, and Z axes orthogonal to each other, the first and second drive electrodes 8 and 9 resonate. The AC voltage having a frequency is applied to drive and vibrate the second arm 3 starting from the second arm 3 on which the first and second drive electrodes 8 and 9 are arranged. Are driven and vibrated in the opposite direction (the driving vibration direction indicated by the solid arrow and the dotted arrow). All of the four second arms 3 and the four weight portions 7 are synchronously driven and vibrated in the direction opposite to the second arm 3 (drive signal direction). The drive vibration direction in the inertial force detection element 1 is the X-axis direction. It has become.

  At this time, in the present invention, for example, the AC voltage applied to the first drive electrode 8 and the AC voltage applied to the second drive electrode 9 are applied in opposite phases to each other, and the second on the positive side of the Y axis is applied. The driving vibration state of the arm 3 and the driving vibration state of the second arm 3 on the negative side of the Y-axis are made to be just opposite. That is, when the distance between the second arm 3 on the positive side of the Y-axis is narrowed, the distance between the second arm 3 on the negative side of the Y-axis is increased.

  As a result, in the inertial force detection element 1 described above, the two second arms 3 arranged on the positive side of the X axis vibrate in opposite directions, and the two second arms 3 arranged on the negative side of the X axis. Vibrate in opposite directions, and the second arm 3 arranged on the positive side of the Y axis and the second arm 3 arranged on the negative side of the Y axis also vibrate in the opposite directions.

  A specific angular velocity detection will be described.

  In such an inertial force detection element 1, for example, when an angular velocity is generated clockwise around the Z axis, the inertial force detection element 1 is driven with respect to the weight part 7 as shown in FIG. Since the Coriolis force is generated in a direction orthogonal to the vibration direction (Coriolis direction indicated by a solid arrow and a dotted arrow), it is possible to generate a distortion due to the clockwise angular velocity of the Z axis in the second arm 3. . The Coriolis direction of the inertial force detection element 1 is the Y-axis direction. When the Coriolis force is generated, each sensing electrode 10 disposed on the second arm 3 senses the distortion of the second arm 3, and the polarity of the sensing electrode 10 determines the direction in which the Coriolis force is generated. For example, two sensing electrodes 10 disposed on each of the second arms 3 are provided to sense the difference between the inner and outer strains of the second arm 3 to determine the direction of Coriolis force generation. Good. Since the strain elongation rate inside the second arm 3 is different from the strain elongation rate outside, the difference in strain can be sensed. Similarly, when the counterclockwise angular velocity of the Z axis is generated, the distortion of the second arm 3 may be sensed.

  In addition, when an angular velocity is generated clockwise around the Y axis, the direction perpendicular to the driving vibration direction with respect to the weight portion 7 (solid arrow) is synchronized with the driving vibration of the weight portion 7 as shown in FIG. Since the Coriolis force is generated in the Coriolis direction indicated by a dotted arrow), the second arm 3 can be distorted due to the clockwise angular velocity of the Y axis. The Coriolis direction of the inertial force detection element 1 is the Z-axis direction. When the Coriolis force is generated, each sensing electrode 10 disposed on the second arm 3 senses the distortion of the second arm 3, and the polarity of the sensing electrode 10 determines the direction in which the Coriolis force is generated. For example, the generation direction of the Coriolis force may be determined by sensing the difference between the positive Z-axis distortion and the negative Z-axis distortion of the second arm 3. Since the elongation rate of strain on the positive side of the Z axis of the second arm 3 is different from that of strain on the negative side of the Z axis, a difference in strain can be sensed. Similarly, when the angular velocity is generated counterclockwise on the Y axis, the distortion of the second arm 3 may be sensed.

  With the above configuration, when the first arm 2 is arranged in the X-axis direction and the second arm 3 is arranged in the Y-axis direction with respect to the X-axis, Y-axis, and Z-axis orthogonal to each other, If drive vibration is performed in the axial direction, distortion caused by the angular velocity around the Z axis can be generated in the second arm 3, and if this distortion is sensed, the angular velocity around the Z axis can be detected. Therefore, it is not necessary to stand the inertial force detection element 1 in the Z-axis direction, and the height can be reduced. Further, distortion caused by the angular velocity around the Y axis can be generated in the second arm 3, and if this distortion is sensed, the angular velocity around the Y axis can also be detected.

  In particular, in the inertial force detection element 1, the second arm 3 is vibrated in the X-axis direction to sense the distortion of the second arm 3 due to the angular velocity. Is generated as vibration in the Y-axis direction or vibration in the Z-axis direction due to the angular velocity. Accordingly, vibration in the X-axis direction and vibration in the Y-axis direction or Z-axis direction due to the angular velocity are generated in the second arm 3, and at this time, the vibration frequency in the X-axis direction of the second arm 3 and the Y-axis direction are generated. The vibration frequency in the direction and the vibration frequency in the Z-axis direction are the resonance frequency in the X-axis direction, the resonance frequency in the Y-axis direction, and the resonance frequency in the Z-axis direction, respectively. When the distortion of the second arm 3 is sensed, it is sensed based on the vibration frequency of the second arm 3 in the X-axis direction, so the resonance frequency of the second arm 3 in the X-axis direction and the Y-axis direction or the Z-axis direction. The sensitivity can be improved if the frequency difference between the resonance frequencies is smaller.

  In addition, you may form an acceleration detection part in the inertial force detection element 1 of the inertial force sensor of this invention.

  In the inertial force detection element 1, the acceleration detection unit senses the distortion of the first arm 2 caused by the acceleration in the first arm 2 formed thinner than the second arm 3, and detects the acceleration. do it.

  The strain in the first arm 2 in the Z-axis direction due to the acceleration in the Y-axis direction is sensed to detect the acceleration in the Y-axis direction, or the first arm 2 in the Z-axis direction due to the acceleration in the Z-axis direction is detected. What is necessary is just to detect the acceleration in the Z-axis direction by sensing the strain.

  With the above configuration, it is possible to retain the function as an acceleration sensor while retaining the function as an angular velocity sensor.

  Further, the acceleration detection unit may be formed as follows.

  A counter substrate facing the weight portion 7 is disposed and a counter electrode is disposed on each of the facing surfaces of the weight portion 7 and the counter substrate so that the thickness of the first arm 2 is smaller than that of the second arm 3, resulting from acceleration. The acceleration may be detected by sensing the capacitance change between the counter electrodes.

  Detects the acceleration in the Y-axis direction by sensing the capacitance change between the counter electrodes in the Z-axis direction due to the acceleration in the Y-axis direction, or between the counter electrodes in the Z-axis direction due to the acceleration in the Z-axis direction The acceleration in the Z-axis direction may be detected by sensing the change in electrostatic capacity.

  With the above configuration, it is possible to retain the function as an acceleration sensor while retaining the function as an angular velocity sensor.

  The inertial force sensor including the vibration isolating mechanism of the inertial force detection element 1 configured and operated as described above will be described below.

  FIG. 5 is a front sectional view of the inertial force sensor according to the present invention, and FIG. 6 is a plan view of the inertial force sensor. FIG. 5 is a cross-sectional view at the approximate center in the vertical direction of FIG. In the cross-sectional view of FIG. 5, it is very difficult to see the cross-sectional view of the inertial force detection element 1. Therefore, the inertial force detection element 1 is expressed as a substantially rectangular parallelepiped object. The same applies to the drawings subsequent to FIG.

  The storage body 11 stores the inertial force detection element 1 and is a package made of ceramic or metal. In FIG. 5, the upper portion of the storage body 11 is opened on the container, but if necessary, a lid may be provided and sealed.

  The support body 12 is a plate-like elastic body, and supports the inertial force detection element 1 on the storage body 11. The support 12 can use a conductor. In this case, the support has a function of electrically connecting the inertial force detection element 1 and the storage body 11.

  A bent portion 13 is formed on the support 12. The width direction of the bent portion 13 in the support 12 is a direction parallel to the XY plane.

  The adhesive layer 14 is made of an adhesive for fixing the inertial force detection element 1 to the support 12, and the adhesive layer 15 is made of an adhesive for fixing the support 12 to the storage body 11.

  The inertial force sensor 16 is composed of the above components.

  A method for manufacturing the inertial force sensor 16 will be described below with reference to FIGS. As a method for manufacturing the inertial force detection element 1, a method of forming a lower electrode, a PZT thin film, and an upper electrode on a Si substrate by thin film technology and processing them into a predetermined shape by etching is known. Omitted.

  7 to 15 are views showing a method of manufacturing an inertial force sensor according to one embodiment of the present invention. In particular, FIG. 7 is a view of a lead frame, FIG. 8 is a view after adhering an adhesive film, and FIG. FIG. 10 is a front sectional view of FIG. 9, FIG. 11 is a view after attaching an inertial force detection element, FIG. 12 is a front sectional view of FIG. 11, and FIG. 13 is a view after cutting the outer periphery of the lead frame. FIG. 14 is a front sectional view of FIG. 13, and FIG. 15 is a front sectional view after bending the lead frame.

  In FIG. 7, a lead frame 21 is made of a conductive metal plate, and finally becomes the support 12 in FIG. The lead frame 21 is composed of a part surrounding the outer periphery like a frame, a substantially square part located in the center, and an elongated part connecting the two. The elongated part connecting the two is the part that finally becomes the support 12.

  FIG. 8 shows a state in which an adhesive film 22 that covers a substantially square portion at the center of the lead frame 21 is attached. The adhesive film 22 also covers a part of an elongated portion that connects a substantially square portion at the center of the lead frame 21 and a portion surrounding the outer periphery like a frame.

  9 and 10 show the lead frame 21 and the central portion of the adhesive film 22 punched out by a press. Here, the entire substantially square portion of the central portion of the lead frame 21 is removed and the outer periphery of the adhesive film 22 is left.

  11 and 12 show an arrangement in which the inertial force detection element 1 is arranged on the lead frame 21 via the adhesive film 22. The inertial force detection element 1 is bonded to the lead frame 21 by the adhesive film 22.

  13 and 14 show a frame-shaped portion on the outer periphery of the lead frame 21 cut and removed by a press.

  FIG. 15 shows an elongated portion of the lead frame 21 that is bent. This bending process can be performed by a known press method. And the inertial force sensor can be manufactured by arranging the lead frame 21 and the inertial force detection element 1 shown in FIG.

  The anti-vibration principle for the inertial force sensor as described above will be described below.

In order to detect the angular velocity, the weight portion 7 that is a mass portion is driven, and the drive cycle is often set to several tens of kHz such as 20 kHz or 40 kHz. Here, if the natural frequency of the inertial force sensor 16 is made the same as the drive frequency, there is a risk of resonance, which must be avoided. In general, it is known that a lower natural frequency is better for a certain vibration frequency from the viewpoint of vibration isolation. And the natural frequency f is m where the mass of the vibrating object is m and the spring constant is k.
f = 1 / 2π · (k / m) 1/2
Therefore, if the spring constant is reduced, the natural frequency can be lowered.

  Therefore, since the spring constant can be reduced by bending the support 12 in the thickness direction, the natural frequency can be reduced, and thereby the vibration isolation effect can be exhibited.

  Further, the direction of the support 12 in the width direction at the bent portion 13 is parallel to the plane on which the first arm 2 and the second arm 3 are arranged. This will be described with reference to FIG. 6. When attention is paid to the support body 12 extending in the Y-axis direction, the width direction of the support body 12 in the bent portion 13 is the Y-axis direction. When attention is paid to the support body 12 extending in the Y-axis direction, the width direction of the support body 12 in the bent portion 13 is the X-axis direction. In other words, the direction of the support 12 in the width direction at the bending portion 13 is parallel to the XY plane, and the plane on which the first arm 2 and the second arm 3 are arranged is also parallel to the XY plane. It will be a good relationship.

  As described above, the direction in the width direction of the support 12 in the bending portion 13 is parallel to the plane on which the first arm 2 and the second arm 3 are arranged, and thus the following effects are obtained. Since the first arm 2 and the second arm 3 are arranged in a plane parallel to the XY plane, the first arm 2 and the second arm 3 are easily bent in the Z-axis direction which is a direction perpendicular to the plane. The fact that it is easy to bend easily deforms when it receives an external force, and if the deformation is too large, the inertial force detection element 1 may be damaged due to the weight portion 7 colliding with surrounding components. On the other hand, since the direction of the support 12 in the width direction at the bent portion 13 is parallel to the XY plane, the support 12 is easily bent in the Z-axis direction, which is a direction perpendicular to the XY plane. Here, since the support body 12 is a component as a vibration isolation mechanism, being easily bent means that it is easy to absorb external impacts and vibrations. Accordingly, the inertial force detection element 1 is configured to be weak against the external force in the Z-axis direction. However, the external force in the Z-axis direction can be more absorbed by the structure of the support 12, so that the inertial force detection element 1. The external force acting in the Z-axis direction can be reduced.

  Further, since the length in the Z-axis direction is longer than the length in the XY plane direction of the length from the inertial force detection element 1 to the storage body 11 of the support body 12, it is particularly excellent in absorbing external force in the XY plane direction. The external force acting on the inertial force detection element 1 in the XY plane direction can be reduced.

  On the contrary, if the length in the XY plane direction is made longer than the length in the Z-axis direction from the inertial force detection element 1 to the storage body 11 of the support 12, it becomes particularly excellent in absorbing external force in the Z-axis direction. External force in the XY plane direction acting on the detection element 1 can be reduced.

  Further, as shown in FIG. 6, when the support 12 is viewed in plan on the XY plane, there are a structure that extends in the X-axis direction and a structure that extends in the Y-axis direction. . In this case, for example, the support body 12 extending in the X-axis direction is easily bent not only in the Z-axis direction but also in the X-axis direction because the width direction of the bent portion 13 is the Y-axis direction. become. Similarly, the support body 12 extending in the Y-axis direction is configured to be easily bent not only in the Z-axis direction but also in the Y-axis direction because the width direction of the bent portion 13 is the X-axis direction. Accordingly, the ease of movement of the inertial force detection element 1 in the X-axis direction and the Y-axis direction is the same, and the X-axis direction and the Y-axis direction have similar characteristics in terms of vibration isolation.

  Note that the inertial force sensor of the present invention is not limited to the structure described with reference to FIGS. It can take various configurations. The variations will be described below.

  FIG. 16 is a front sectional view of a first variation of the inertial force sensor according to one embodiment of the present invention. The same components as those of the inertial force sensor shown in FIGS. 1 to 15 are denoted by the same reference numerals, and detailed description thereof will be omitted. The inertial force sensor shown in FIGS. 1 to 15 has a configuration in which the inertial force detection element 1 is disposed on the support 12. However, the inertial force sensor of FIG. It is configured to be hung on. In the case of this configuration, an effect is obtained that the product height in the height direction, that is, the Z-axis direction can be made lower than that of the inertial force sensor shown in FIGS.

  FIG. 17 is a front sectional view of the second variation. A support 12 is suspended from the storage body 11, an IC 17 is disposed on the support 12, and the inertial force detection element 1 is attached to the lower surface of the IC 17. By integrating the IC 17 and the inertial force detection element 1, the mass that vibrates becomes the sum of these masses and increases compared to the case of the inertial force detection element 1 alone, so that the natural frequency is lowered and resonance is prevented. It becomes preferable from.

  FIG. 18 is a plan view of the third variation. When viewed in plan on the XY plane, the support 12 extending in the Y-axis direction is not provided, and only the support 12 extending in the X-axis direction is provided. It has a configuration. In this case, the anti-vibration function in the X-axis direction is superior to the anti-vibration function in the Y-axis direction, but the inertial force detection element 1 detects the Coriolis force in the X-axis direction, but detects the Coriolis in the Y-axis direction. This configuration may be used when the force is not detected.

  FIG. 19 is a perspective view of the fourth variation, in which TAB (Tape Automated Bonding) is used as an example of the support 12 used in FIG. An insulating stack 24 is provided in the center of the lead frame 21, and the inertial force detection element 1 or the IC 17 integrated therewith is disposed here. Further, the attachment portions 25 formed at both ends of the lead frame 21 are attached to the storage body 11.

  FIG. 20 is a plan view of the fifth variation, and FIG. 21 is a front sectional view of the fifth variation. As shown in FIGS. 20 and 21, in the fifth variation, two bent portions 13 are provided for one support 12. Further, in the XY plane direction, the shape is bent in the plane, not in the thickness direction. With this shape, the spring constant can be further reduced, the natural frequency can be lowered, and the anti-vibration function can be improved.

  The inertial force sensor of the present invention is not limited to the configuration described above. For example, the inertial force detection element 1 may have a diaphragm structure. Further, the angular velocity detection axis direction may be a triaxial direction of X, Y, and Z. Regarding the acceleration, it may be one that detects the three-axis direction, and can also be applied to one that does not detect acceleration.

  The inertial force sensor according to the present invention has an excellent effect of enabling detection of angular velocities in a plurality of rotation axis directions while preventing erroneous detection due to external impact or vibration.

DESCRIPTION OF SYMBOLS 1 Inertial force detection element 2 1st arm 3 2nd arm 4 3rd arm 5 Slit 6 Frame (fixed part)
7 Weight (mass)
8 First drive electrode 9 Second drive electrode 10 Sensing electrode (detection unit)
DESCRIPTION OF SYMBOLS 11 Storage body 12 Support body 13 Bending part 14 Adhesive layer 15 Adhesive layer 16 Inertial force sensor 17 IC
21 Lead frame 22 Adhesive film 23 Bending part 24 Stacking part 25 Mounting part

Claims (10)

A mass part, a connecting part that has flexibility and supports the mass part, has a predetermined thickness and is formed on the same plane, and a fixing part that holds the mass part via the connecting part are at least different 2 An inertial force detection element including a detection unit for detecting an angular velocity having a direction as a rotation axis;
A support for supporting the inertial force detection element,
In plan view, the support has a first part extending in the X-axis direction on the XY plane, and a second part extending in the Y-axis direction from the first part,
The inertial force sensor according to claim 1, wherein the first part and the second part are at right angles.   The inertial force sensor according to claim 1, further comprising an IC in contact with the inertial force detection element.   The inertial force sensor according to claim 1, wherein the inertial force detection element is disposed on a back surface side of the support. The inertial force detection element is supported by the support via a first adhesive layer,
A storage body for holding the inertial force detection element via the support;
The support is in contact with the housing via a second adhesive layer;
The support includes a first portion having a portion that contacts the first adhesive layer, a first bent portion that bends in the thickness direction from the first portion, and a portion that contacts the second adhesive layer. A second part having a second part bent in the thickness direction from the second part, and a third part being a part between the first bent part and the second bent part. ,
The inertial force sensor according to any one of claims 1 to 3, wherein the second bent portion is located inward of an inner edge portion of the second adhesive layer.   The inertial force sensor according to claim 4, wherein a length in the Z-axis direction of the support is longer than a length in the XY plane direction of the third portion of the support.   6. The inertial force sensor according to claim 4, wherein the first bent portion is located outside the outer edge portion of the first adhesive layer.   The inertial force sensor according to any one of claims 4 to 6, wherein the first bending portion is positioned outside the inertial force detection element.   The inertial force sensor according to any one of claims 4 to 7, wherein the first adhesive layer has a structure that continuously surrounds the center of the fixed portion in a plan view.   The inertial force sensor according to any one of claims 4 to 8, wherein the first bent portion is located at a position lower than the second bent portion.   The inertial force sensor according to any one of claims 4 to 9, wherein an outer edge portion of the second portion is located outside an outer edge portion of the second adhesive layer.

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