JP2007271514A - Angular velocity sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electromagnetic drive type angular velocity sensor comprising a mechanism capable of efficiently controlling leak vibration with a simple structure. <P>SOLUTION: This angular velocity sensor 99 is an electromagnetic drive type angular velocity sensor for detecting Coriolis force, and comprises a fixing member 4, a vibration mass object 10 supported by a fixing member 4 so that it can be displaced for the fixing member 4 in a first direction 1, a detection mass object 11 supported by the vibration mass object 10 so that it can be displaced for the vibration mass object 10 in a second direction 2 crossing in the first direction 1, a drive wire 12 formed on the vibration mass object 10 for displacing the vibration mass object 10 in the first direction 1 by Lorentz force, and a displacement adjusting wire 13 formed on the vibration mass object 10 and extending in the first direction 1. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an angular velocity sensor, and more particularly to an electromagnetically driven angular velocity sensor.

  One method for detecting angular velocity is a method for detecting Coriolis force applied to a vibrating object. As an angular velocity sensor based on this detection principle, for example, an angular velocity sensor having a frame, a vibration mass body, and a mass body (hereinafter referred to as a detection mass body) as main components is known (for example, Patent Documents). 1).

  In Patent Document 1, the vibration mass body is coupled to the frame via four webs so as to be displaceable in a fixed direction (first direction). The detection mass body is coupled to a block that is immovably coupled to the vibration mass body via a flexible beam, and is thereby arranged to be displaceable in the second direction with respect to the block. Then, the acting Coriolis force is detected by measuring the change in the capacitance between the comb electrodes caused by the displacement of the detection mass body.

  Patent Document 1 also discloses a configuration in which two vibration mass bodies and two detection mass bodies are arranged in one frame. These two oscillating masses are subjected to vibrations of opposite phases, and a difference between the two measurement signals is formed, whereby disturbances such as acceleration are filtered out.

  Examples of a method for vibrating the vibrating mass body include an electromagnetic driving method (for example, see Patent Document 2) and an electrostatic driving method (for example, see Patent Document 3). The electromagnetic driving method is a method in which Lorentz force acting on a current under a magnetic field is used as a driving force for vibration. The electrostatic drive method is a method in which an electrostatic force that acts when a voltage is applied between electrodes is used as a driving force for vibration. As a specific mechanism, there is, for example, a comb-type electrostatic drive mechanism that has two comb-shaped electrodes and is disposed so as to face each other so that the electrodes mesh with each other. A voltage is applied between the two comb electrodes, and an electrostatic force acting between the electrodes is used as a driving force.

  In recent years, in order to reduce the size of these angular velocity sensors, semiconductor process technology has been used for the manufacture thereof (for example, see Patent Document 3). In order to manufacture an angular velocity sensor with high accuracy, each component of the angular velocity sensor needs to be processed with high accuracy. However, processing by semiconductor process technology is, for example, about ± 10% in the thickness direction, about ± 10% in the pattern width of several μm, and pattern alignment accuracy is about ± 0.5 μm in the case of general equipment used for MEMS. There are manufacturing variations. For example, if the support spring, which is a member that supports the vibration mass body with respect to the fixed member, is not processed as designed, a deviation occurs between the vibration orientation of the vibration mass body assumed in the design and the actual vibration orientation. End up. Even if the machining accuracy is sufficiently high, vibration in an unnecessary direction may be secondarily excited for design reasons. These undesirable directions of vibration are called leakage vibrations.

  In an environment where no Coriolis force is present, ideally the detection mass should simply vibrate in the first direction. However, when there is leakage vibration, the detection mass body is displaced along the second direction even if there is no Coriolis force due to the influence. Therefore, the leakage vibration becomes a factor causing the detection error of the angular velocity sensor. In order to improve the accuracy of the angular velocity sensor, it is necessary to suppress this leakage vibration.

  As this suppression means, for example, Patent Document 3 includes (1) a configuration in which a fixed electrode and a movable electrode are added, (2) a configuration in which a vibration absorber made up of a vibration absorbing beam and a vibration absorbing mass is added, and (3) air resistance. A configuration in which a plurality of blades for suppressing leakage vibration is added, and (4) a configuration in which a damper for suppressing leakage vibration due to gas viscous resistance is added.

Non-Patent Document 1 also proposes suppressing leakage vibration by electrostatic force generated by applying a voltage between adjacent comb teeth of the comb electrode.
JP-A-8-220125 (Page 4, FIGS. 2 and 3) Japanese Patent Laid-Open No. 11-264730 (7th page, FIG. 5) Japanese Patent Laid-Open No. 11-132770 WA Clark et al., "Surface Micromachined Z-Axis Vibratory Rate Gyroscope", Sensor and Actuator Workshop, 1996, pp.283-287

  However, the above-described leakage vibration suppressing means has a problem that the structure becomes complicated. This will be described below.

  First, regarding the leakage vibration suppressing means described in Patent Document 3, when a configuration in which a fixed electrode and a movable electrode are provided, an electrode is required on each of the fixed portion side and the movable portion side, and the structure of the angular velocity sensor is complicated. It becomes. In addition, a complicated structure is required in any of a configuration in which a vibration absorbing beam and a vibration absorbing mass are provided, a configuration in which a plurality of blades are provided, and a configuration in which a damper that uses gas viscous resistance is provided. The structure becomes complicated.

  Further, the leakage vibration suppressing means described in Non-Patent Document 1 described above needs to be formed so that the comb teeth of adjacent comb electrodes can be controlled electrically independently. For this reason, even in this configuration, the structure of the angular velocity sensor is complicated.

  Further, the electromagnetic drive method has a problem that leakage vibration occurs due to a mask alignment error. This will be described below.

  In the electromagnetic drive system, the structure (vibrating mass body, detection mass body, etc.) and the drive wiring are formed in separate steps. For this reason, a mask alignment error occurs between the structure forming mask and the drive wiring forming mask. As a result, a deviation occurs between the driving vibration direction of the vibrating mass and the direction in which the driving force is generated, and leakage vibration is caused by this deviation. In order to suppress this leakage vibration, application of the suppression means in the electrostatic drive system is conceivable. However, in the electrostatic drive system, the structure and the drive mechanism are formed using the same mask. For this reason, leakage vibration based on mask alignment error does not occur in the electrostatic drive method. Therefore, even if various suppression means in the electrostatic drive system are simply applied to the electromagnetic drive system, it is difficult to directly suppress the leakage vibration based on the deviation between the driving direction of the vibrating mass body and the driving force generation direction. .

  Further, the leakage vibration suppressing means described in Patent Document 3 is a means for suppressing leakage vibration in the thickness direction of the angular velocity sensor, and cannot directly suppress leakage vibration in the in-plane direction. This is a problem when the detected angular velocity is the thickness direction of the angular velocity sensor, and when the Coriolis force to be measured is in the in-plane direction of the angular velocity sensor, it is particularly important to suppress leakage vibration in the in-plane direction. It is.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an angular velocity sensor that has a simple structure and can reliably suppress leakage vibration due to mask alignment error.

  An angular velocity sensor according to the present invention is an electromagnetically driven angular velocity sensor that detects a Coriolis force, a fixed member, and a vibrating mass supported by the fixed member so as to be displaceable in a first direction with respect to the fixed member. A detection mass body supported by the vibration mass body so as to be displaceable in a second direction intersecting the first direction with respect to the vibration mass body, and the vibration mass body formed by the Lorentz force Drive wiring for displacing in the first direction and displacement adjustment wiring formed on the vibrating mass body and extending in the first direction are included.

  The angular velocity sensor of the present invention is of an electromagnetic drive type, and generates a Lorentz force by causing a current to flow through a drive wiring in a magnetic field, thereby displacing a vibrating mass body in a first direction. By passing a current through the displacement adjustment wiring under this magnetic field, the Lorentz force can be generated and the vibrating mass body can be displaced in the second direction intersecting the first direction, as described above.

  Therefore, if the current flowing through the displacement adjustment wiring is adjusted, the displacement amount of the vibration mass body in the second direction is adjusted. With this adjustment function, leakage vibration in the second direction can be suppressed. As described above, since the magnetic field generated by the electromagnetic drive system is used, leakage vibration can be suppressed only by providing the displacement adjustment wiring on the vibration mass body.

  In addition, the angular velocity sensor of the present invention has an effect that leakage vibration in the in-plane direction of the angular velocity sensor can be directly suppressed.

  In addition, as described above, the displacement adjustment wiring according to the present invention suppresses leakage vibration by using a magnetic field that originally exists in the electromagnetic drive system, and therefore suppresses leakage vibration only by providing the displacement adjustment wiring on the vibration mass body. be able to. Thereby, unlike the case where the conventional fixed electrode and the movable electrode are provided, it is not necessary to add another electrode to the fixed member, and the configuration is simple. Further, since it is not necessary to add a complicated structure as in the prior art and only a simple displacement adjustment wiring is added, the configuration can be simplified in this respect as well. Further, since it is not necessary to electrically separate adjacent comb teeth as in the prior art, the configuration is simple in this respect as well.

  Also, the electromagnetically driven angular velocity sensor of the present invention can be used simultaneously in the photolithography process at the time of manufacturing by using the same mask as the displacement adjusting wiring as the leakage vibration suppressing means and the driving wiring as the means for electromagnetic driving. It can be formed. For this reason, if one mask pattern is drawn so that the displacement adjustment wiring and the drive wiring are at right angles, both are stably formed at right angles without being affected by the mask alignment error. Therefore, the force for suppressing the leakage vibration and the driving force are set at a right angle without being affected by manufacturing variations. Thereby, leakage vibration due to mask alignment error can be suppressed with good controllability.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that “displacement” used in the following description refers to a change in position due to vibration.

(Embodiment 1)
Initially, the structure of the angular velocity sensor of this Embodiment is demonstrated using FIGS. 1-3.

  FIG. 1 is a plan view schematically showing the configuration of the angular velocity sensor according to Embodiment 1 of the present invention. Referring to FIG. 1, for the convenience of explanation, coordinate axes X-axis, Y-axis, and Z-axis are introduced. 1, the X axis is the horizontal direction, the Y axis is the vertical direction, and the Z axis is the vertical direction. The X axis coincides with a first direction in which the vibrating mass 10 can be easily displaced. The Y axis coincides with a second direction in which the detection mass body 11 can be displaced with respect to the vibration mass body 10. The Z axis coincides with the rotation axis direction of the angular velocity that is the measurement target of the angular velocity sensor of the present embodiment.

  The angular velocity sensor 99 of the present embodiment has two angular velocity sensor portions 98, a fixing member 4, and a connecting spring 7. In FIG. 1, the two angular velocity sensor portions 98 that are divided into left and right are connected symmetrically by a connecting spring 7. The angular velocity sensor unit 98 and the connecting spring 7 are formed on the fixed member 4. The connecting spring 7 is not directly fixed to the fixing member 4 existing on the lower surface thereof, and floats on the fixing member 4. Since the connecting spring 7 can be elastically deformed in the X-axis direction, the vibrating mass bodies 10 of the left and right angular velocity sensor units 98 can vibrate at substantially the same frequency and opposite phase in the X direction.

Next, the configuration of the angular velocity sensor unit will be described.
The angular velocity sensor unit 98 includes a support spring 6, a vibration mass body 10, a detection spring 16, a detection mass body 11, a pair of comb electrode portions 17a and 17b, a drive wiring 12, a monitor wiring 14, Displacement adjustment wiring 13. The vibration mass body 10 is supported by the fixing member 4 via the support spring 6. Although details will be described later, the support spring 6 is fixed only to the fixing member 4 at one end portion, and the other portions are floated hollow. The other end of the support spring 6 is connected to the vibration mass body 10. The support spring 6 has high rigidity in the Y-axis direction and the Z-axis direction, and has a shape that is elastically most easily deformed in the X-axis direction as a whole. Due to the deformation of the support spring 6, the vibration mass body 10 is vibrationally displaced substantially in the X-axis direction.

  The detection mass body 11 is supported by the vibration mass body 10 via the detection spring 16. The detection mass body 11 is not directly coupled to the fixing member 4 and floats on the fixing member 4. The detection spring 16 has high rigidity in the X-axis direction and the Z-axis direction, but deforms elastically as a whole in the Y-axis direction. Due to this anisotropic spring characteristic, the vibration mass body 10 and the detection mass body 11 move substantially integrally in the X-axis direction, but the detection mass body 11 moves in the Y-axis direction with respect to the vibration mass body 10. It can be displaced relatively by spring deformation.

  The detection mass body 11 has a rectangular donut shape, and a comb-teeth electrode portion 17a having an electrode surface perpendicular to the Y axis is formed on the inner surface thereof.

  The fixed comb electrode portion 17b is fixed on the fixing member 4, and is disposed in the donut-shaped hole of the detection mass body described above. The fixed comb electrode portion 17b includes a comb electrode having an electrode surface perpendicular to the Y axis. The comb electrode of the fixed comb electrode portion 17b and the comb electrode of the comb electrode portion 17a are arranged such that both electrode surfaces face each other. The pair of comb electrode portions 17a and 17b has a function as one capacitor. Although not shown in the figure, a wire bond is used to connect the electrically isolated isolated pad disposed on the fixing member 4 and the fixed comb electrode portion 17b for detecting the capacitance of the capacitor from the outside. Wiring is provided for electrical extraction, for example. Electrical connection is made from the isolated pad to an external control board (not shown).

  On the upper surface of the vibrating mass 10, the drive wiring 12 extends in the Y-axis direction as indicated by a thick line in FIG. 1. As shown by the thin line in FIG. 1, auxiliary wiring for flowing current from the outside to the driving wiring 12 is formed on the upper surface of the support spring 6. Further, the drive wiring 12 of the left angular velocity sensor unit 98 and the drive wiring 12 of the right angular velocity sensor unit 98 are connected by auxiliary wiring on the upper surface of the support spring 6 at the upper center in the drawing. As a result, one current path is formed, and both ends of the current path exist on the upper surface of the support spring 6 at the center lower part in FIG. When a current is applied to both ends, the current flows so as to go around the connection spring 7, and thus a current in the opposite direction flows between the left drive wiring 12 and the right drive wiring 12.

  Further, as shown by a thick line in FIG. 1, the monitor wiring 14 extends in the Y-axis direction on the upper surface of the vibration mass body 10. As shown by a thin line in FIG. 1, auxiliary wiring extends from the end of the monitor wiring 14 through the upper surface of the support spring 6 to the end of the support spring 6.

  Further, as shown by a thick line in FIG. 1, a displacement adjustment wiring 13 extends in the X-axis direction on the upper surface of the vibration mass body 10. As shown by thin lines in FIG. 1, further auxiliary wiring extends from the displacement adjustment wiring 13 to the end of the support spring 6 through the upper surface of the support spring 6.

  FIG. 2 is a schematic cross-sectional view taken along the line II-II in FIG. 1, and schematically shows the configuration of the angular velocity sensor according to the first embodiment of the present invention. With reference to FIG. 2, a part of the support spring 6 is fixed to the fixing member 4 in the anchor region 5. Here, the anchor region refers to a region where the fixing member 4 and other portions existing on the upper surface thereof are fixed. Portions other than the anchor region 5 of the support spring 6 are floating in the air. The vibration mass body 10, the detection mass body 11, and the connection spring 7 are lifted from the fixed member 4. The fixed comb electrode portion 17 b is fixed to the fixing member 4 at the anchor region 5. The monitor wiring 14 and the drive wiring 12 are formed on the upper surface of the vibration mass body 10.

  In addition, the drive wiring 12, the monitor wiring 14, and the displacement adjustment wiring 13 are pads provided on the surface of the short part fixed to the fixing member 4 in the supporting spring 6 by auxiliary wiring passing over the supporting spring 6. (Not shown) and electrical connection is made from this pad to the external control board. In the sectional view, auxiliary wirings and pads are omitted.

  FIG. 3 is an explanatory diagram schematically showing an anchor region in the first embodiment of the present invention. Referring to FIG. 3, each support spring 6 has an end portion serving as an anchor region 5 and is fixed to fixing member 4. The other end is connected to the vibrating mass 10. The support spring 6 is floating from the fixing member except for the anchor region (hatched portion) 5, and this floating portion functions as a spring. The fixed comb electrode portion 17 b is disposed in the anchor region 5 and is fixed to the fixing member 4. Note that the elements in FIG. 3 that are the same as those in FIG.

Next, the use environment of the angular velocity sensor according to the present embodiment will be described with reference to FIG.
FIG. 4 is a cross-sectional view schematically showing an environment in which the angular velocity sensor according to Embodiment 1 of the present invention is used. Referring to FIG. 4, angular velocity sensor 99 of the present embodiment is placed on base 43. The periphery of the angular velocity sensor 99 is covered with the package 40.

  A permanent magnet 41 is attached to the inner surface of the package 40, whereby a uniform magnetic field is applied to the angular velocity sensor 99. The direction 42 of the magnetic field is perpendicular to the main surface of the angular velocity sensor 99 and corresponds to the direction of the Z axis in FIG. In addition, the sign of the Z-axis direction component of the magnetic field is arbitrary. An electromagnet may be used instead of the permanent magnet.

  In FIG. 4, only two lead wires 44 are illustrated in a simplified manner, but actually the lead wires 44 extend as many as necessary. One end of the lead wire 44 is connected to pads such as the drive wiring 12, the monitor wiring 14, and the displacement adjustment wiring 13 formed on the end of the support spring 6 corresponding to the anchor region 5 in the angular velocity sensor 99, A low-resistance silicon is used as a conductive comb electrode side wiring pad for detection connected from the silicon surface of the region fixed to the fixing member 4 using silicon itself as a conductor, or by wire bonding from the fixed comb electrode portion 17b. It is connected to the isolated pad that was taken out. The other end of the lead wire 44 is connected to a control device (not shown). This control device has a function of applying a current to the drive wiring 12 and the displacement adjustment wiring 13, a function of measuring an induced electromotive force generated in the monitor wiring 14, and a static mass to detect the displacement of the detection mass body in the Y-axis direction. And a function of measuring electric capacity.

  Then, the measurement principle of the angular velocity of the angular velocity sensor of this Embodiment is demonstrated using FIG.

  Referring to FIG. 1, an alternating current is applied to drive wiring 12 extending in the Y-axis direction. Then, since a uniform magnetic field is applied by the magnet in the Z-axis direction, a Lorentz force in the X-axis direction acts on the drive wiring 12. The Lorentz force is a component that oscillates in time according to the AC current described above. Therefore, a force that vibrates in the X-axis direction is applied to the vibrating mass body 10 to which the drive wiring 12 is attached. Here, since the vibration mass body 10 is suspended by the support spring 6 so as to be displaceable in the X-axis direction, the vibration mass body 10 is vibrated in the X-axis direction. In response to this displacement, an induced electromotive force is generated in the monitor wiring 14 provided on the vibrating mass 10 under a uniform magnetic field in the Z-axis direction. The induced electromotive force is monitored by the control device, whereby the amplitude of vibration of the vibrating mass is detected. By adjusting the current value of the drive wiring 12 with reference to the detection result, the vibration mass body 10 can be vibrated with a desired amplitude.

  Referring to FIG. 1, the drive wiring 12 of the left angular velocity sensor unit 98 and the drive wiring 12 of the right angular velocity sensor unit 98 are connected by auxiliary wiring so that the current direction flows in the opposite direction. Therefore, the direction of the acting Lorentz force is reversed between the drive wiring 12 of the left angular velocity sensor unit 98 and the drive wiring 12 of the right angular velocity sensor unit 98. As a result, a reverse force is applied along the X axis to the vibrating mass 10 to which each drive wiring 12 is attached. Here, since each vibration mass body 10 is supported by the support spring 6 so as to be capable of vibration displacement along the X axis, each vibration mass body 10 vibrates in the opposite phase along the X axis. Furthermore, since the adjacent angular velocity sensors 98 are connected by the connecting spring 7 so as to be relatively displaceable in the X-axis direction, this vibration is stabilized. In addition, since the two angular velocity sensor portions 98 connected by the support spring 7 have a symmetrical structure with respect to a plane perpendicular to the X-axis that is imaginary at the center position of the support spring 7, The vibration mass body 10 is stabilized at substantially the same frequency and opposite phase.

  The detection mass body 11 is independent of the fixing member 4 and is suspended by the vibration mass body 10 via the detection spring 16. Since the detection spring 16 has high rigidity in the X-axis direction, the detection mass body 11 also vibrates in the X-axis direction as the vibration mass body 10 vibrates in the X-axis direction.

  When an angular velocity around the Z axis is applied to the angular velocity sensor 99, a Coriolis force in the Y axis direction corresponding to the angular velocity is applied to the detection mass body 11 that vibrates in the X axis direction. Since the detection spring 16 described above is easily elastically deformed as a whole in the Y-axis direction, the detection mass body 11 is oscillated and displaced in accordance with the Coriolis force acting in the Y-axis direction. Accordingly, the comb electrode portion 17a provided on the inner peripheral surface of the detection mass body 11 having a rectangular donut shape also vibrates in the Y-axis direction.

  On the other hand, the fixed comb electrode portion 17 b provided further inside the region surrounded by the donut-shaped hole portion of the detection mass body 11 is fixed to the fixing member 4. Therefore, the comb electrode provided in the fixed comb electrode portion 17 b is in a state of being fixed relative to the fixing member 4. And the capacitor | condenser comprised from the comb-tooth electrode with which the comb-tooth electrode part 17a was equipped, and the comb-tooth electrode with which the fixed comb-tooth electrode part 17b was equipped is the electrode accompanying the vibration of the detection mass body 11 in the Y-axis direction. Since the inter-distance varies, the capacitance also varies. Therefore, when the control device measures this capacitance, it is possible to know the vibrational displacement of the detection mass body 11 in the Y-axis direction. Since this displacement corresponds to the Coriolis force in the Y-axis direction caused by the angular velocity in the Z-axis direction, the angular velocity in the Z-axis direction can be known.

  The above description of the measurement principle of the angular velocity sensor is for an ideal state. An actual angular velocity sensor is affected by leakage vibration due to manufacturing or design problems. This leakage vibration will be described below.

  First, in general, when the vibration mass body and the support spring are not processed symmetrically with respect to the three axes corresponding to the coordinate axes X, Y, and Z shown in FIG. 1, leakage vibration may occur.

  Furthermore, there are also leakage vibrations specific to the electromagnetic drive system. This point will be described with reference to FIGS. With reference to FIG. 1, an example of leakage vibration caused by a manufacturing problem in an electromagnetically driven angular velocity sensor will be described first. A drive wiring 12 is provided on the upper surface of the vibration mass body 10. Although details of the manufacturing method of the angular velocity sensor of the present invention will be described later, the vibrating mass body 10 and the drive wiring 12 are formed through separate photolithography processes. Therefore, a mask alignment error may occur between the vibration mass body 10 and the drive wiring 12. When the extending direction of the vibrating mass 10 is used as a reference for the coordinate axis, if there is an angle error in mask alignment, the drive wiring 12 extends strictly deviating from the Y-axis direction. As a result, the current vector of the current flowing through the drive wiring 12 mainly has a component in the Y-axis direction, but has a slight component in the X-axis direction. The current component in the X-axis direction generates a Lorentz force in the Y-axis direction under a magnetic field in the Z-axis direction. For this reason, the vibrating mass 10 mainly vibrates in the X-axis direction, but slightly vibrates in the Y-axis direction. This is one of the leakage vibration phenomena. The leakage vibration in the Y-axis direction of the vibration mass body 10 is transmitted to the detection mass body 11 via the detection spring 16. Due to this influence, the detection mass body 11 vibrates in the Y-axis direction even when Coriolis force does not exist. For this reason, even if the angular velocity is zero, the capacitance of the capacitor composed of the comb electrodes facing each other changes in a vibrational manner as if the angular velocity exists.

  On the other hand, in the case of the electrostatic drive method, unlike the electromagnetic drive method, the leakage vibration caused by the mask alignment error described above does not usually cause a problem. For example, in the case of an electrostatic drive type angular velocity sensor that generates vibration using electrostatic force between comb-teeth electrodes, a structure for generating an electrostatic drive force and a structure such as a vibration mass body are used in the manufacture thereof. Since the tooth electrode structure is integral, patterning is simultaneously performed using the same mask. For this reason, it is not necessary to consider a mask alignment error.

  In addition to the above, the cause of leakage vibration due to manufacturing problems may be due to deviation from the design shape due to variations in the etching process. The occurrence of leakage vibration due to deviation from the design shape can occur regardless of the drive system.

  Next, an example of leakage vibration caused by a design problem in an electromagnetically driven angular velocity sensor will be described with reference to FIG. The drive wiring 12 is formed on the upper surface of the vibration mass body 10. For this reason, due to the Lorentz force acting on the drive wiring 12, a force in the X-axis direction acts on the upper surface portion of the vibrating mass 10 to which the drive wiring is attached. The point of action of the Lorentz force is shifted in the Z-axis direction from the center of gravity of the vibrating mass 10, and the Lorentz force acts in the X-axis direction, so that a rotational moment in the Y-axis direction is generated. This rotational moment disturbs translational vibration in the pure X-axis direction of the vibrating mass 10 and causes leakage vibration.

  Next, a means for suppressing leakage vibration in the angular velocity sensor of the present embodiment will be described with reference to FIGS.

  Referring to FIGS. 1 and 2, a displacement adjustment wiring 13 extending in the X-axis direction is provided on the upper surface of the vibration mass body 10. A current is applied to the displacement adjustment wiring 13 from the control device via an auxiliary wiring. According to this configuration, when an arbitrary current is passed through the displacement adjustment wiring 13, a Lorentz force having an arbitrary magnitude in the Y axis direction can be applied to the displacement adjustment wiring 13 under a magnetic field in the Z axis direction. . By applying the Lorentz force in the Y-axis direction with an optimum magnitude, leakage vibration in the Y-axis direction of the vibrating mass 10 can be suppressed to the maximum.

  For example, if the displacement in the Y-axis direction of the detection mass body 11 when the angular velocity around the Z-axis is zero, leakage vibration can be suppressed. Since the displacement of the detection mass body 11 in the Y-axis direction is detected by the capacitance of a capacitor composed of comb-teeth electrodes, the vibration of this capacitance may be made zero or minimum.

  FIG. 5 is a graph showing an example of current applied to the angular velocity sensor according to Embodiment 1 of the present invention.

  With reference to FIG. 5, an example of the current applied to the displacement adjustment wiring 13 is shown. A current having a phase opposite to that of the drive current 62 is applied to the displacement adjustment wiring 13 as the displacement adjustment current 63. The amplitude of the displacement adjustment current 63 is adjusted so that the leakage vibration is minimized. FIG. 5 shows an example, and the phase may be the same phase or other optimal phase difference instead of the opposite phase. The amplitude is optimized in accordance with the actual structure of the element, the degree of mask alignment error in the photolithography process at the time of manufacturing, the degree of deviation from the design dimension due to variations in etching processing, and the like.

  Next, features of the leakage vibration suppressing mechanism in the present embodiment will be described with reference to FIGS. The displacement adjustment wiring 13 which is a leakage vibration suppressing mechanism in the present embodiment can be patterned with the same mask as the driving wiring 12. In order to clarify the effect by the feature, a case where the leakage vibration suppression mechanism is a comb electrode formed simultaneously with the vibration mass body 10 and the support spring 6 is also shown as a comparative example.

  FIG. 6 is an explanatory view showing a coordinate system of a structure of an angular velocity sensor of an electromagnetic drive system and a drive coordinate system. In FIG. 6, components unnecessary for explanation are omitted. Referring to FIG. 6, the main configuration of the angular velocity sensor is schematically drawn at the top of the diagram, and the coordinate system for showing the angular relationship of each configuration is drawn at the bottom of the diagram. In this coordinate system, a coordinate system 71 of a structure having coordinate axes based on the structure such as the vibrating mass 10 and the support spring 6 is indicated by a solid line, and the coordinate axis in the direction along the extending direction of the drive wiring 12 is indicated. The drive coordinate system 72 is shown by a broken line. When a mask alignment error occurs between the structure formation mask and the drive wiring formation mask, the drive wiring 12 does not exactly follow the Y axis of the coordinate system 71 and is shifted by a predetermined error θ. Lorentz force (electromagnetic driving force) generated by passing a current through the drive wiring 12 acts in a direction orthogonal to the extending direction of the drive wiring 12. For this reason, this Lorentz force deviates from the X axis of the coordinate axis 71 of the structure by an angle θ as indicated by an arrow 73 in the figure. Thereby, the Lorentz force vector indicated by the arrow 73 is the sum of the X-axis direction component and the Y-axis direction component of the coordinate system 71 of the structure, and includes the Y-axis direction component. For this reason, when the Lorentz force of the drive wiring 12 is generated, the vibration mass body 10 leaks and vibrates in the Y-axis direction of the coordinate system 71 of the structure.

  FIG. 7 shows the azimuth relationship between the leakage vibration suppressing force and the electromagnetic driving force when the leakage vibration suppressing means of Non-Patent Document 1 is simply applied to the electromagnetically driven angular velocity sensor shown in FIG. It is explanatory drawing. Components that are unnecessary for the description are omitted. Referring to FIG. 7, a pair of comb electrodes 30 and 31 are provided as leakage vibration suppressing means of Non-Patent Document 1. Of the pair of comb electrodes 30, 31, the mass body side comb teeth 30 are attached to the vibrating mass body 10, and the fixing member side comb teeth 31 are attached to the fixing member 4. Further, the pair of comb electrodes 30 and 31 are arranged so that both electrode surfaces face each other.

  The leakage vibration suppression force generated by the pair of comb electrodes 30 and 31 is given by the electrostatic force generated between the electrode surfaces of the pair of comb electrodes 30 and 31 facing each other. For this reason, this leakage vibration suppressing force acts in the direction indicated by the arrow 74 in the figure, that is, in the Y-axis direction of the coordinate system 71 of the structure. When the leakage vibration suppressing means is made to function so as to cancel the component in the Y-axis direction in the coordinate system 71 of the structure of the electromagnetic driving force in order to suppress the leakage vibration, the resultant force 76 has a smaller absolute value than the electromagnetic driving force 73. Become. Since a desired vibration amplitude cannot be obtained in this state, the current flowing through the drive wiring 12 is adjusted, and the electromagnetic driving force is increased. Then, the leakage vibration component in the Y-axis direction also becomes large corresponding to the increment. For this reason, the control for setting the optimum values of the electromagnetic driving force and the leakage vibration suppressing force tends to diverge, and the control becomes difficult. In FIG. 7, only one mass body side comb tooth 30, which is a comb tooth extending from the vibrating mass body 10, is drawn to simplify the illustration, but this number is arbitrary. Further, the number of the fixing member side comb teeth 31 may be increased corresponding to the number of the mass body side comb teeth 30. The parts denoted by the same reference numerals as those in FIG. 6 indicate the same contents, and the description thereof is omitted.

  FIG. 8 is an explanatory diagram showing the orientation relationship between the leakage vibration suppressing force and the electromagnetic driving force in the first embodiment of the present invention. Components that are unnecessary for the description are omitted. Referring to FIG. 8, displacement adjustment wiring 13 which is a mechanism of electromagnetic leakage vibration suppression means is added to the angular velocity sensor of FIG. In the manufacture of the angular velocity sensor, the displacement adjustment wiring 13 is formed simultaneously with the drive wiring 12. Therefore, the relative positional relationship between the displacement adjustment wiring 13 and the drive wiring 12 is not affected by the mask alignment error. For this reason, the orthogonal relationship between the direction of the Lorentz force acting on the displacement adjustment wiring 13 and the direction of the Lorentz force acting on the drive wiring 12 is not affected by manufacturing variations and can always be maintained. Therefore, when the electromagnetic driving force 73 is taken in one coordinate axis direction of the driving coordinate system 72, the direction of the other orthogonal coordinate axis coincides with the direction of the electromagnetic leakage vibration suppressing force 75. On the other hand, since the photolithography process of the drive wiring 12 and the displacement adjustment wiring 13 and the photolithography process of the structure such as the vibration mass body 10 and the support spring 6 are separate, a mask alignment error may occur by an angle θ. . Here, when the magnitude of the electromagnetic leakage vibration suppression force 75 is set so as to cancel the Y-axis component in the coordinate system 71 of the structure of the electromagnetic driving force 73, the resultant force 76 is more absolute than the electromagnetic driving force 73. The value increases. In this state, since the vibration amplitude becomes larger than the initial value, the current flowing through the drive wiring 12 for correction is reduced, and the electromagnetic driving force is reduced. As a result, the leakage vibration component in the Y-axis direction correspondingly decreases, so that the current flowing through the displacement adjustment wiring 13 can be reduced. For this reason, in contrast to the case of FIG. 7, there is a tendency that the control in which the optimum combination of the electromagnetic driving force 73 and the leakage vibration suppressing force 75 is set converges. Therefore, according to the present embodiment, the leakage vibration can be corrected efficiently. The parts denoted by the same reference numerals as those in FIGS. 6 and 7 indicate the same contents, and the description thereof is omitted.

  Further, according to the present embodiment, the displacement adjustment wiring 13 which is the leakage vibration suppressing means is a simple wiring pattern. Since its structure is simple, it is easy to manufacture and has good controllability. Further, there is an advantage that the displacement adjustment wiring 13 can be formed simultaneously with the driving wiring 12.

(Embodiment 2)
FIG. 9 is a plan view schematically showing the configuration of the angular velocity sensor according to Embodiment 2 of the present invention. Since the configuration other than the drive wiring 12 is the same as that shown in FIG. 1, the same elements are denoted by the same reference numerals, and the description thereof is omitted. The difference from the first embodiment is that one vibration mass body 10 includes a plurality of drive wirings 12. Referring to FIG. 9, unlike the first embodiment, two drive wirings 12 are formed symmetrically with respect to one vibration mass body 10 in the vertical direction. In addition, auxiliary wiring for electrically connecting the left and right drive wirings is provided on the upper surface of the connection spring 7.

  Although the number of current paths is one in the first embodiment, there are two current paths in the present embodiment. If the direction of the current is selected so that the same current flows through the two current paths and the current in the same direction flows through the two drive wirings 12 attached to one vibration mass body 10, the vibration mass The Lorentz force acting on the body 10 is substantially the same as in the first embodiment. Therefore, in this case, the vibrating mass body 10 is driven in the same manner as in the first embodiment. A feature of the present embodiment is that a difference can be provided in the currents flowing in the two current paths. Referring to FIG. 9, when the upper portion of the vibrating mass 10 vibrates greatly in the X-axis direction as compared with the lower portion, the current flowing through the upper drive wiring 12 is greater than the current flowing through the lower drive wiring 12. Is adjusted to be smaller. Then, the driving force acting on the upper part of the vibrating mass 10 becomes smaller than the driving force acting on the lower part. Using this action, the vibrating mass is adjusted so as to have an ideal translational motion in the X-axis direction. Thereby, leak vibration is suppressed and the effect which improves the precision of an angular velocity sensor is acquired.

(Embodiment 3)
FIG. 10 is a cross-sectional view schematically showing the configuration of the angular velocity sensor according to Embodiment 3 of the present invention. Since the configuration other than the drive wiring 12 and the monitor wiring 14 is the same as that shown in FIG. 2, the same reference numerals are given to the same elements, and the description thereof is omitted. Referring to FIG. 10, the difference from the first embodiment is that one vibration mass body 10 includes drive wiring 12 and monitor wiring 14 in a vertically symmetrical arrangement on both the front and back surfaces.

  In the first and second embodiments, the drive wiring 12 exists only on the upper surface of the vibration mass body 10 by design. For this reason, due to the Lorentz force acting on the drive wiring 12, a force in the X-axis direction acts on the upper surface portion of the vibrating mass 10 to which the drive wiring is attached. The point of action of the Lorentz force is shifted from the center of gravity of the vibrating mass 10 to the Z axis, and since the Lorentz force acts in the X axis direction, a rotational moment in the Y axis direction is generated. This rotational moment disturbs the pure lateral vibration of the vibrating mass 10 and causes leakage vibration. On the other hand, in the present embodiment, if currents in the same and the same direction are supplied to the front and back drive wirings 12, the rotational moment acting on the front and back is canceled, and leakage vibration in the Z-axis direction is suppressed. As a result, since the leakage vibration that needs to be dealt with is mainly in the Y-axis direction, it is effectively leaked by the Lorentz force in the Y-axis direction due to the current application to the displacement adjustment wiring 13 described in the first and second embodiments. Vibration can be suppressed.

  Further, it is possible to provide a difference in the current flowing through the driving wirings 12 on the front and back sides. By providing an arbitrary difference, the rotational moment around the Y axis applied to the vibrating mass can be adjusted. When the vibrating mass 10 is undesirably rotating and vibrating around the Y axis, the adjustment can cancel the rotation. As a result, since the leakage vibration of the vibrating mass body 10 can be suppressed, the accuracy of the angular velocity sensor is improved.

  In the present embodiment, the monitor wiring 14 is also formed on both the front and back surfaces. As a result, the symmetry of the weight balance in the vertical direction and the symmetry of the force that the monitor wiring receives from the magnetic field increase, so that leakage vibration in the Z-axis direction can be suppressed. As a result, since the leakage vibration is mainly in the Y-axis direction, it can be effectively suppressed by the Lorentz force in the Y-axis direction by applying the current to the displacement adjustment wiring 13 described in the first and second embodiments. It becomes.

  In the present embodiment, both the drive wiring 12 and the monitor wiring 14 are formed on both front and back surfaces, but a certain effect can be obtained even when only one of the drive wiring 12 and the monitor wiring 14 is provided on both front and back surfaces.

  Next, the manufacturing method of the angular velocity sensor of this Embodiment is demonstrated using FIGS.

  FIG. 11 is a cross sectional view schematically showing a first step of the method of manufacturing the angular velocity sensor in the third embodiment of the present invention. Referring to FIG. 11, the fixing member 4 is formed with a recess serving as a gap for enabling the vibration mass body or the like to be supported hollowly. As the fixing member 4, for example, a glass substrate can be used. On the other hand, on the back surface of the silicon substrate 53, the drive wiring 12 on the back side and the monitor wiring 14 on the back side are formed by a thin film forming technique. Although not shown, electrical insulation is provided between the silicon substrate 53 and the drive wiring 12 and between the silicon substrate 53 and the monitor wiring 14. The insulating property can be imparted by forming an insulating film or oxidizing the surface of silicon.

  FIG. 12 is a cross sectional view schematically showing a second step of the method of manufacturing the angular velocity sensor according to Embodiment 3 of the present invention. Referring to FIG. 12, fixing member 4 and silicon substrate 53 are bonded together. Lamination can be performed, for example, by anodic bonding. Thereafter, the silicon substrate 53 is ground and polished to a predetermined thickness. Next, on the front side of the silicon substrate 53, the drive wiring 12 on the front side and the monitor wiring 14 on the front side are formed by a thin film formation technique. Although not shown, a wire bond pad or the like necessary for electrical connection with the displacement adjustment wiring 13 or the outside is also formed on the front side of the silicon substrate 53. Specifically, for example, an Al—Si alloy film is formed on the silicon substrate 53 after ensuring electrical insulation from the silicon substrate 53. This alloy film is patterned into a desired shape by a semiconductor process technique.

  In addition, each comb-tooth electrode uses the perpendicular etching surface which opposes the comb-tooth structure formed by anisotropically etching the low resistance silicon substrate as an electrode, and silicon itself is also used as a wiring material. On the fixed member 4, an insulating film on the silicon surface is opened while being electrically insulated from other wiring members, and a movable comb electrode-side wiring pad (not shown) for taking out from the sensor element is formed. . On the other hand, on the side of the fixed comb electrode portion 17b, a base part that fixes the comb teeth and an electrically isolated isolated pad (not shown) arranged on the fixing member 4 are wire-bonded, and further the isolated pad To the outside of the sensor element.

  FIG. 13 is a cross sectional view schematically showing a third step of the method of manufacturing the angular velocity sensor according to Embodiment 3 of the present invention. Referring to FIG. 13, a resist mask 54 is formed by a photolithography technique. The mask pattern corresponds to the shape of the support spring 6, the connecting spring 7, the vibration mass body 10, the detection mass body 11, and the like. Subsequently, the silicon substrate 53 is etched with good anisotropy by, for example, a silicon anisotropic deep processing technique using ICP-RIE (Inductively Coupled Plasma Reactive Ion Etching). Thereafter, the resist is removed.

Thus, the angular velocity sensor of the present embodiment shown in FIG. 10 is completed.
Although the silicon substrate 53 is used in the present embodiment, the present invention is not limited to this, and a substrate made of another material may be used.

  Further, in this embodiment, anodic bonding is used for bonding the fixing member 4 and the silicon substrate 53, but the present invention is not limited to this. Techniques relating to low melting point glass and eutectic metal can also be used.

  In the present embodiment, the fixing member 4 is made of glass that can be anodically bonded. However, if another substrate bonding method is used, the material is not limited to glass but may be silicon, for example.

(Embodiment 4)
FIG. 14 is a cross-sectional view schematically showing a configuration of the angular velocity sensor according to Embodiment 4 of the present invention. Since the components other than the drive wiring 12 and the monitor wiring 14 are the same as those shown in FIG. 10 in the third embodiment, the same elements are denoted by the same reference numerals and the description thereof is omitted. Referring to FIG. 14, the difference from the third embodiment is that drive wiring 12 and monitor wiring 14 are embedded in vibration mass body 10.

  In the first and second embodiments, the drive wiring 12 exists only on the upper surface of the vibration mass body 10 by design. For this reason, the Lorentz force acting on the drive wiring 12 causes a lateral force to act on the upper surface portion of the vibration mass body 10 where the drive wiring is attached. The point of action of the Lorentz force is shifted upward from the center of gravity of the vibrating mass 10, and the Lorentz force acts in the lateral direction, so that a rotational moment is generated. This rotational moment disturbs the pure lateral vibration of the vibrating mass 10 and causes leakage vibration.

  On the other hand, in the present embodiment, since the drive wiring 12 is embedded, the direction of the line connecting the center of gravity of the vibration mass body 10 and the point of action of the Lorentz force is the same as the direction of the Lorentz force. can do. Therefore, since no rotational moment occurs around the Y axis, leakage vibration in the Z axis direction can be suppressed. As a result, since the leakage vibration is mainly in the Y-axis direction, it can be effectively suppressed by the Lorentz force in the Y-axis direction by applying the current to the displacement adjustment wiring 13 described in the first and second embodiments. It becomes.

  In the present embodiment, the monitor wiring 14 is also embedded. As a result, the symmetry of the weight balance in the vertical direction and the symmetry of the force that the monitor wiring receives from the magnetic field increase, so that leakage vibration in the Z-axis direction can be suppressed. As a result, since the leakage vibration is mainly in the Y-axis direction, it can be effectively suppressed by the Lorentz force in the Y-axis direction by applying the current to the displacement adjustment wiring 13 described in the first and second embodiments. It becomes.

  Next, a method for manufacturing the angular velocity sensor according to the present embodiment will be described. First, for example, a groove for embedding the drive wiring 12 and the monitor wiring 14 is formed in a silicon substrate. Next, an insulating layer is formed, and then a conductive material such as copper is deposited. Next, the surface is flattened. The silicon substrate embedded with the conductive material pattern thus obtained is bonded to the fixing member 4 in place of the silicon substrate 53 in FIG. After that, the angular velocity sensor of the present embodiment is obtained through the same process as that of the third embodiment.

  If the wiring is embedded in the groove penetrating in the thickness direction as in the present embodiment, there is no wiring that is covered with the silicon substrate 53, so that the power supply only needs to be performed from the surface of the silicon substrate. There is.

  In the present embodiment, both the drive wiring 12 and the monitor wiring 14 are embedded, but a certain effect can be obtained even if either one is embedded.

  Further, in the present embodiment, the configuration in which the drive wiring 12 and the monitor wiring 14 are embedded in the groove penetrating in the thickness direction is shown, but the present invention is not limited to this, and a part thereof is embedded. If this is the case, the generation of rotational moment can be reduced. Further, even when a groove that does not penetrate in the thickness direction is provided on both the front and back surfaces, and the drive wiring 12 and the monitor wiring 14 are embedded in the groove on both surfaces, the generation of rotational moment can be reduced.

(Embodiment 5)
FIG. 15 is a cross-sectional view schematically showing a configuration of the angular velocity sensor according to the fifth embodiment of the present invention. Referring to FIG. 15, except that displacement sensors 15 are provided above and below each vibration mass body 10, the configuration is the same as that shown in FIG. 1 in the first embodiment. The same reference numerals are given and the description thereof is omitted.

  As described in the first embodiment, the rectangular donut-shaped hole portion of the detection mass body 11 is provided with the comb-tooth electrode portion 17a and the fixed comb-tooth electrode portion 17b. The displacement of the detection mass body 11 in the Y-axis direction is detected. In the present embodiment, a displacement sensor 15 that is a displacement detection mechanism in the Y-axis direction similar to this is further provided in the vibration mass body 10. That is, a rectangular hole is provided on the upper side and the lower side of the vibration mass body 10 in FIG. 15, and a fixed comb electrode portion 17b is formed therein. The fixed comb electrode portion 17b is fixed to the fixing member 4 on the lower surface, and a comb electrode having an electrode surface perpendicular to the Y axis is formed on the outer periphery. A comb electrode portion 17 a having an electrode surface perpendicular to the Y axis is also provided on the inner peripheral surface of the hole of the vibration mass body 10. The comb-tooth electrode portion 17a and the fixed comb-tooth electrode portion 17b are disposed so as to mesh with each other. Capacitance is generated between the comb electrodes, and the displacement of the vibrating mass 10 in the Y-axis direction can be known by measuring the capacitance.

  According to this configuration, the rigidity of the vibration mass body 10 in the Y-axis direction is sufficiently high with respect to the detection spring 16 that is displaced by the Coriolis force. Therefore, the displacement sensor 15 causes leakage vibration in the Y-axis direction of the vibration mass body 10. It can always be detected. Therefore, based on this constant detection, the current flowing through the displacement adjustment wiring 13 is controlled so that the leakage vibration is zero or minimized, so that the angular velocity can be detected with higher accuracy.

  In this embodiment, a capacitor composed of opposing comb electrodes is used as the displacement sensor 15. However, the present invention is not limited to this, and the displacement of the vibrating mass 10 in the Y-axis direction can be detected. Any sensor may be used.

  Each embodiment disclosed this time must be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The present invention can be applied particularly advantageously to an electromagnetically driven angular velocity sensor.

It is a top view which shows roughly the structure of the angular velocity sensor in Embodiment 1 of this invention. It is sectional drawing which shows schematically the structure of the angular velocity sensor in Embodiment 1 of this invention. It is explanatory drawing which shows roughly the anchor area | region of the angular velocity sensor in Embodiment 1 of this invention. It is sectional drawing which shows roughly the use environment of the angular velocity sensor in Embodiment 1 of this invention. It is a graph which shows an example of the electric current applied to the drive wiring and displacement adjustment wiring of the angular velocity sensor in Embodiment 1 of this invention. It is explanatory drawing which shows the relationship between the coordinate system of the structure of the angular velocity sensor in Embodiment 1 of this invention, and the coordinate system of a drive, and the direction of a drive force. It is explanatory drawing which shows the azimuth | direction relationship between the leakage vibration suppression force and electromagnetic drive force in a comparative example. It is explanatory drawing which shows the azimuth | direction relationship between the leakage vibration suppression force and electromagnetic drive force in Embodiment 1 of this invention. It is a top view which shows roughly the structure of the angular velocity sensor in Embodiment 2 of this invention. It is sectional drawing which shows roughly the structure of the angular velocity sensor in Embodiment 3 of this invention. It is sectional drawing which shows roughly the 1st process of the manufacturing method of the angular velocity sensor in Embodiment 3 of this invention. It is sectional drawing which shows schematically the 2nd process of the manufacturing method of the angular velocity sensor in Embodiment 3 of this invention. It is sectional drawing which shows schematically the 3rd process of the manufacturing method of the angular velocity sensor in Embodiment 3 of this invention. It is sectional drawing which shows schematically the structure of the angular velocity sensor in Embodiment 4 of this invention. It is sectional drawing which shows schematically the structure of the angular velocity sensor in Embodiment 5 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 1st direction, 2nd direction, 3rd direction, 4 fixing member, 5 anchor area | region, 6 support spring, 7 connection spring, 10 vibration mass body, 11 detection mass body, 12 drive wiring, 13 displacement Adjustment wiring, 14 Monitor wiring, 15 Displacement sensor, 17a Comb electrode part, 17b Fixed comb electrode part, 30 Mass body side comb tooth, 31 Fixed member side comb tooth, 40 Package, 41 Permanent magnet, 42 Direction of magnetic field, 43 Base, 44 Lead wire, 53 Silicon substrate, 54 Resist mask, 71 Coordinate system of structure, 72 Drive coordinate system, 73 Electromagnetic drive force, 74 Leakage vibration suppression force of comparative example, 75 Electromagnetic leak vibration suppression force, 76 resultant force, 98 angular velocity sensor part, 99 angular velocity sensor.

Claims (10)

An electromagnetically driven angular velocity sensor that detects Coriolis force,
A fixing member;
A vibrating mass supported by the fixing member so as to be displaceable in a first direction with respect to the fixing member;
A detection mass body supported by the vibration mass body so as to be displaceable in a second direction intersecting the first direction with respect to the vibration mass body;
Drive wiring formed on the vibrating mass and for displacing the vibrating mass in the first direction by Lorentz force;
An angular velocity sensor comprising a displacement adjustment wiring formed on the vibration mass body and extending in the first direction.   The angular velocity sensor according to claim 1, comprising a plurality of the drive wirings arranged symmetrically with respect to the first direction.   The angular velocity sensor according to claim 1, wherein the drive wiring is disposed on both front and back surfaces of the vibration mass body.   The angular velocity sensor according to claim 1, wherein the drive wiring has a structure embedded in the vibration mass body.   The angular velocity sensor according to any one of claims 1 to 4, further comprising a monitor wiring formed on the vibrating mass body and detecting a displacement in the first direction of the vibrating mass body by an induced electromotive force.   The angular velocity sensor according to claim 5, wherein the monitor wiring is disposed on both front and back surfaces of the vibrating mass body.   The angular velocity sensor according to claim 5 or 6, wherein the monitor wiring has a structure embedded in the vibrating mass body.   The angular velocity sensor according to claim 1, further comprising a displacement sensor for detecting a displacement of the vibrating mass body in the second direction.   The angular velocity sensor according to claim 8, wherein the displacement sensor has a pair of opposing comb electrodes. A pair of angular velocity sensor units each including the vibration mass body, the detection mass body, the drive wiring, and the displacement adjustment wiring;
The first mass directions of the angular velocity sensor portions are aligned, and the vibration mass bodies are connected to each other so that the vibration mass bodies of the adjacent angular velocity sensor portions can be displaced in the first direction. The angular velocity sensor according to claim 1, further comprising a connection spring.

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