Piezoelectrically driven tunneling magnetoresistive in-plane detection microgyroscope device

Abstract

A piezoelectric drive type tunnel magnetoresistance in-plane detection micro- gyroscope device, the main structure is composed of bonding substrate, support frame, drive composite beam assembly, detection composite beam assembly, drive mass, detection mass, detection magnet, tunnel magnetoresistance element, piezoelectric film drive electrode assembly, wire and electrode. The support frame is placed on the bonding substrate, the drive mass is connected with the drive composite beam assembly, and the drive mass is connected with the detection mass through the detection composite beam assembly. The tunnel magnetoresistance element is placed on the center of the upper surface of the detection mass and corresponds to the detection magnet deposited in the groove of the center of the bonding substrate. The piezoelectric effect is adopted for driving, the driving displacement is large, and the power consumption is low; the tunnel magnetoresistance effect is detected, the tunnel magnetoresistance element has high sensitivity to weak magnetic field change, the device structure is reasonable and simple, convenient to use, and suitable for miniaturization.

Description

TECHNICAL FIELD

[0001] The present application relates to a piezoelectric drive type tunnel magnetoresistance in-plane detection micro-gyro device, belonging to the technical field of measuring instrument parts of micro-inertial navigation. BACKGROUND

[0002] Inertial technology works in a completely autonomous manner, without contact with the outside world, and has the advantages of autonomy, real-time and non-interference. Gyro is the core device of inertial navigation technology, and plays a crucial role in modern aerospace, national defense and military fields.

[0003] The core of micro-inertial system is gyro, so the volume, cost, precision, overload capacity and other indicators of gyro determine the performance of micro-inertial system. According to the working principle, micro-gyro can be divided into mechanical gyro, optical gyro and MEMS gyro. Mechanical gyro has high precision but large volume and poor overload capacity; optical gyro has relatively small volume but high cost, and can only be applied to high-end fields. In tactical missiles, intelligent shells, unmanned aerial vehicles, unmanned vehicles, image stabilization and other weapon systems, the cost, volume and overload performance requirements are limited. MEMS gyro has the advantages of low cost, small volume and strong impact resistance, so it is widely used in micro-inertial systems.

[0004] In the prior art, the commonly used driving modes of micro-mechanical gyroscopes include electrostatic, piezoelectric, electromagnetic, etc., and the commonly used detection modes of micro-mechanical gyroscopes include piezoresistive, piezoelectric, capacitive, resonant tunneling, electron tunneling effect, etc. As for the driving mode, electrostatic driving has good stability, but the driving amplitude is small; electromagnetic driving has large driving amplitude, but requires large driving voltage; piezoelectric driving has the advantages of small required driving voltage, high precision, small error, good stability, etc. As for the detection mode, piezoresistive detection has low sensitivity and large temperature coefficient, thereby limiting the further improvement of detection precision; piezoelectric effect detection has sensitive drift, slow zero return, and is not suitable for continuous testing; capacitive detection uses comb structure and has high displacement resolution, but the manufacturing process precision requirement of the comb is extremely high, and the yield is low; the sensitivity of resonant tunneling effect is one order of magnitude higher than that of silicon piezoresistive effect, but the detection sensitivity obtained by testing is low, and the existing problems are that the bias voltage is easy to drift due to gyro driving, which leads to unstable work of the gyro; the manufacturing process of the electron tunneling effect device is extremely complex, the detection circuit is relatively difficult to realize, the yield is low, and the device is difficult to work normally, which is not conducive to integration, especially it is difficult to control the distance between the tunnel junction tip and the electrode plate to be nanoscale, and it is difficult to ensure the normal work of the sensor. Tunnel magnetoresistance effect is based on the spin effect of electrons, and there is an insulator or semiconductor non-magnetic layer between the magnetic pinning layer and the magnetic free layer. When the magnetic free layer changes its magnetization direction under the action of an external field, the magnetization direction of the pinning layer remains unchanged. At this time, the relative orientation of the magnetization of the two magnetic layers changes, and a large resistance change can be observed across the magnetic tunnel junction. This physical effect is based on the tunneling effect of electrons in the insulating layer, so it is called tunnel magnetoresistance effect. Tunnel magnetoresistance effect has the advantages of "high sensitivity, miniaturization, and easy detection", and the inventor thinks of applying tunnel magnetoresistance effect to the structure detection of gyroscopes, which can improve the detection sensitivity of micro-gyroscopes by one to two orders of magnitude compared with capacitive gyroscopes. There is no related product in this technical field.

[0005] In the search of the prior art, the prior art 1 "piezoelectric driving and capacitive detection micro solid mode gyroscope" (application number 201110206937.0), the prior art 2 "a micro-mechanical gyroscope based on tunnel magnetoresistance effect" (application number 201510043522.4), and the prior art 3 "electromagnetic driving type tunnel magnetoresistance in-plane detection micro-gyroscope device" (application number 201710695555.6) are found.

[0006] The prior art 1 adopts piezoelectric drive, and a capacitance detection mode, and the capacitance detection adopts a comb structure, and displacement resolution is high, but with further miniaturization, the comb voltage is easy to break down, and will also be attracted to failure when a lateral impact occurs, especially the comb manufacturing process precision requirement is extremely high, and the yield is low, which restricts the development of this direction; the prior art 2 adopts electrostatic drive, and a tunnel magnetoresistance detection mode, and the electrostatic drive also adopts a comb structure, and there are disadvantages of small driving amplitude and high process requirement; the prior art 3 adopts electromagnetic drive, and a tunnel magnetoresistance detection mode, and the electromagnetic drive mode has the advantages of large acting force and fast response speed, but has the disadvantages of large power consumption and easy damage, and is not easy to process and manufacture. SUMMARY

[0007] In order to effectively solve the above problems, the present application provides a piezoelectric drive type tunnel magnetoresistance in-plane detection micro- gyroscope device, which can improve the detection precision of the micro- gyroscope, reduce the power consumption, and ensure a large displacement in the driving direction, so as to facilitate the detection of the micro displacement caused by the weak Coriolis force.

[0008] The technical scheme of the present application is as follows:

[0009] A piezoelectric drive type tunnel magnetoresistance in-plane detection micro- gyroscope device, comprising: a bonding substrate and a support frame arranged on the bonding substrate, a driving mass block is arranged in the inner side of the support frame, a detection mass block is arranged in the inner side of the driving mass block, the corner of the driving mass block is connected with the external support frame through a driving combined beam assembly, the corner of the detection mass block is connected with the driving mass block through a detection combined beam assembly, and a tunnel magnetoresistance element is arranged at the center of the detection mass block.

[0010] Further comprising: a piezoelectric film driving electrode assembly and a detection electrode, the piezoelectric film driving electrode assembly is arranged on the driving combined beam assembly, the piezoelectric film driving electrode assembly comprises a first piezoelectric film driving electrode, a second piezoelectric film driving electrode, a third piezoelectric film driving electrode and a fourth piezoelectric film driving electrode, the first piezoelectric film driving electrode, the second piezoelectric film driving electrode, the third piezoelectric film driving electrode and the fourth piezoelectric film driving electrode are arranged on the driving combined beam assembly respectively, the detection electrode is arranged at a position close to the second piezoelectric film driving electrode and the third piezoelectric film driving electrode, and the tunnel magnetoresistance element is connected with the detection electrode through a signal detection lead wire.

[0011] Optionally, the driving combined beam assembly comprises: a first driving combined beam, a second driving combined beam, a third driving combined beam, and a fourth driving combined beam, the first driving combined beam, the second driving combined beam, the third driving combined beam, and the fourth driving combined beam are respectively arranged at four corners of the driving mass block, the first driving combined beam, the second driving combined beam, the third driving combined beam, and the fourth driving combined beam are identical in structure and each comprises a first driving beam, a second driving beam, and a driving beam connecting block, the first driving beam and the second driving beam are respectively located on two sides of the driving beam connecting block and are parallel to each other, one end of the first driving beam is connected with the driving mass block, the other end of the first driving beam is connected with a support frame, one end of the second driving beam is connected with the driving mass block, the other end of the second driving beam is connected with one end of the driving beam connecting block, and the other end of the driving beam connecting block is connected with the support frame.

[0012] Optionally, the detection combined beam assembly comprises: a first detection combined beam, a second detection combined beam, a third detection combined beam, and a fourth detection combined beam, the first detection combined beam, the second detection combined beam, the third detection combined beam, and the fourth detection combined beam are respectively arranged at corners of the detection mass block, the first detection combined beam, the second detection combined beam, the third detection combined beam, and the fourth detection combined beam are identical in structure and each comprises a first detection beam, a second detection beam, and a detection beam connecting block, the detection beam connecting block is provided with a protruding portion on both sides of one end thereof and has a whole "T" shape, the first detection beam and the second detection beam are respectively located on two sides of the detection beam connecting block and are connected with the protruding portion, the other ends of the first detection beam and the second detection beam are connected with the detection mass block, and the other end of the detection beam connecting block is connected with the driving mass block.

[0013] Optionally, the first piezoelectric thin film driving electrode, the second piezoelectric thin film driving electrode, the third piezoelectric thin film driving electrode, and the fourth piezoelectric thin film driving electrode are respectively arranged on the first driving beam at the four corners of the driving mass block.

[0014] Optionally, the first piezoelectric thin film driving electrode, the second piezoelectric thin film driving electrode, the third piezoelectric thin film driving electrode, and the fourth piezoelectric thin film driving electrode are identical in structure and each comprises a first piezoelectric driving top electrode, a second piezoelectric driving top electrode, a third piezoelectric driving top electrode, a fourth piezoelectric driving top electrode, a piezoelectric driving material layer, and a piezoelectric driving bottom electrode, the piezoelectric driving bottom electrode is arranged on the first driving beam, the piezoelectric driving material layer is arranged on the piezoelectric driving bottom electrode, the first piezoelectric driving top electrode, the second piezoelectric driving top electrode, the third piezoelectric driving top electrode, and the fourth piezoelectric driving top electrode are respectively arranged at four corners of the piezoelectric driving material layer and have gaps between each other.

[0015] Optionally, the bonding substrate is square in shape, and a square recess is formed in the center of the bonding substrate, and a detection magnet is arranged in the recess.

[0016] Optionally, the detection magnet comprises a permanent magnet, an energized coil, or a light-controlled magnet.

[0017] Optionally, the magnetic concentration unit is in the shape of a triangle or a square.

[0018] Optionally, the support frame has a square outer structure and is the same size as the bonding substrate.

[0019] The present application has the following advantages:

[0020] The present application adopts piezoelectric driving and tunnel magnetoresistance detection, solves the problem of weak driving capacity and weak Coriolis force detection of the existing micro-mechanical gyroscope, adopts piezoelectric driving mode, has large driving displacement, requires small driving voltage, and has low power consumption. When detecting, the magnetoresistance element with high sensitivity is used to detect the micro-displacement caused by the Coriolis force, which has high sensitivity, miniaturization and easy detection. The in-plane detection micro-mechanical gyroscope has the advantages of small damping effect and high precision compared with the off-plane detection micro-mechanical gyroscope. Moreover, the micro-mechanical gyroscope of the present application adopts piezoelectric driving, which can provide a driving amplitude much larger than that provided by electrostatic driving. The purpose is to make the micro-gyroscope produce a larger Coriolis force under the Coriolis effect, and then produce a large amplitude stable oscillation in the detection direction, and at the same time, the tunnel magnetoresistance effect with high sensitivity is used for detection to improve the detection precision of the micro-gyroscope. The micro-gyroscope of the present application deposits high magnetic permeability soft magnetic material on the detection magnet, has a magnetic concentration effect, realizes the enhancement of the local magnetic field strength, thereby improving the magnetic field change rate, forms a stable high change rate magnetic field, and when the magnetic field sensed by the tunnel magnetoresistance element changes, the resistance of the tunnel magnetoresistance element will change dramatically under the weak magnetic field change. This change can improve the detection precision of the micro-gyroscope of the present application by one to two orders of magnitude. The micro-mechanical gyroscope of the present application has reasonable structure design, simple interface circuit and high detection precision, and can solve the problem of angular rate signal detection. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall structure of the present application;

[0022] Figure 2 It is a top view of the overall structure of the present application;

[0023] Figure 3 It is a structure diagram of the bonding substrate of the present application;

[0024] Figure 4 It is a top view of the bonding substrate of the present application;

[0025] Figure 5 Support frame structure diagram of the present application;

[0026] Figure 6 Drive mass and detection mass structure diagram of the present application;

[0027] Figure 7 Drive mass and detection mass top view of the present application;

[0028] Figure 8 Drive mass structure diagram of the present application;

[0029] Figure 9 Drive mass top view of the present application;

[0030] Figure 10 Drive composite beam schematic diagram of the present application;

[0031] Figure 11 Drive composite beam top view of the present application;

[0032] Figure 12 Detection mass structure diagram of the present application;

[0033] Figure 13 Detection mass top view of the present application;

[0034] Figure 14 Detection composite beam structure diagram of the present application;

[0035] Figure 15 Detection composite beam top view of the present application;

[0036] Figure 16 Electrode and wire distribution schematic diagram of the present application;

[0037] Figure 17 Electrode and wire distribution top view of the present application;

[0038] Figure 18 Piezoelectric thin film drive electrode structure diagram of the present application;

[0039] Figure 19 Piezoelectric thin film drive electrode top view of the present application;

[0040] Figure 20 Piezoelectric thin film drive electrode side view of the present application.

[0041] The figures shown, the list of reference signs is as follows:

[0042] 1 - bonding substrate; 2 - detection magnet; 3 - magnetic concentrating unit; 4 - support frame; 5 - drive mass; 6 - detection mass; 7 - tunnel magnetoresistance element; 8 - first drive composite beam; 9 - second drive composite beam; 10 - third drive composite beam; 11 - fourth drive composite beam; 12 - first detection composite beam; 13 - second detection composite beam; 14 - third detection composite beam; 15 - fourth detection composite beam; 16 - first piezoelectric drive bottom electrode; 17 - second piezoelectric drive bottom electrode; 18 - third piezoelectric drive bottom electrode; 19 - fourth piezoelectric drive bottom electrode; 20 - detection electrode; 21 - detection lead wire; 22 - first piezoelectric thin film drive electrode; 23 - second piezoelectric thin film drive electrode; 24 - third piezoelectric thin film drive electrode; 25 - fourth piezoelectric thin film drive electrode; 26 - first drive beam; 27 - second drive beam; 28 - drive beam connecting block; 29 - first detection beam; 30 - second detection beam; 31 - detection beam connecting block; 32 - first piezoelectric drive top electrode; 33 - second piezoelectric drive top electrode; 34 - third piezoelectric drive top electrode; 35 - fourth piezoelectric drive top electrode; 36 - piezoelectric drive material layer. DETAILED DESCRIPTION

[0043] Embodiments of the present application are described in detail below with reference to the attached drawing figures, wherein the same or like reference numerals and characters are used throughout the drawing figures to designate the same or like components. The embodiments described below are exemplary only, and are not intended to be limiting of the present application as defined by the claims and their equivalents.

[0044] In the description of the present application, it is to be understood that the orientations or positional relationships indicated by the terms "center", "upper", "lower", "front", "back", "left", "right" and the like are based on the orientations or positional relationships shown in the drawings, and are merely for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the combinations or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, during the description of the embodiments of the present application, the device position relationships of "upper", "lower", "front", "back", "left", "right" and the like in all the drawings are based on the standard of the drawings. Figure 1

[0045] In the description of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected", "connected" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0046] ​The application is further described below with reference to the drawings:

[0047] As shown in Figure 1 , 2 , a piezoelectric drive type tunnel magnetoresistance in-plane detection micro- gyroscope device comprises a bonding substrate 1, a support frame 4, a drive composite beam assembly, a detection composite beam assembly, a drive mass 5, a detection mass 6, a detection magnet 2, a magnetic concentration unit 3, a tunnel magnetoresistance element 7, a piezoelectric film drive electrode assembly, a detection electrode 20 and a signal detection wire 21.

[0048] The support frame 4 is arranged above the bonding substrate 1, and the support frame 4 is connected to the corners of the drive mass 5 through the first drive composite beam 8, the second drive composite beam 9, the third drive composite beam 10 and the fourth drive composite beam 11 respectively, and the drive mass 5 is connected to the corners of the detection mass 6 through the first detection composite beam 12, the second detection composite beam 13, the third detection composite beam 14 and the fourth detection composite beam 15 respectively, and the tunnel magnetoresistance element 7 is arranged at the center of the upper surface of the detection mass 6.

[0049] As shown in Figure 3 , 4 , the bonding substrate 1 is square as a whole, and a square groove is arranged at the center of the bonding substrate 1, the detection magnet 2 is arranged in the groove, the depth of the groove is greater than the thickness of the detection magnet 2, the detection magnet 2 can be a permanent magnet, an energized coil, a light-controlled magnet or any device capable of generating a magnetic field, the detection magnet 2 is arranged at the center of the bonding substrate 1, and the magnetic concentration unit 3 is deposited above the detection magnet 2 and can be obtained by process etching, the magnetic concentration unit 3 can be triangular or square and has a magnetic concentration effect.

[0050] As shown in Figure 5 , 6 , 7, the support frame 4 has a square external structure and is consistent in size with the bonding substrate 1, the support frame 4 is used for supporting the drive mass 5 and the detection mass 6, the drive mass 5 is arranged inside the support frame 4,

[0051] The drive composite beam assembly comprises the first drive composite beam 8, the second drive composite beam 9, the third drive composite beam 10 and the fourth drive composite beam 11, the corners of the drive mass 5 are connected to the external support frame 4 through the first drive composite beam 8, the second drive composite beam 9, the third drive composite beam 10 and the fourth drive composite beam 11 respectively, the detection mass 6 is arranged at the center of the support frame 4 and inside the drive mass 5, and the corners of the detection mass 6 are connected to the drive mass 5 through the first detection composite beam 12, the second detection composite beam 13, the third detection composite beam 14 and the fourth detection composite beam 15 respectively.

[0052] As Figure 8 , 9 , 10, 11, the first drive composite beam 8, the second drive composite beam 9, the third drive composite beam 10, the fourth drive composite beam 11 are respectively arranged at the four corners of the drive mass 5, the first drive composite beam 8, the second drive composite beam 9, the third drive composite beam 10, the fourth drive composite beam 11 are the same in structure size, and are all composed of a first drive beam 26, a second drive beam 27 and a drive beam connecting block 28, the first drive beam 26 and the second drive beam 27 are elongated beam structures, that is, the length of the beam is much greater than its width, the first drive beam 26 and the second drive beam 27 are respectively located on the two sides of the drive beam connecting block 28 and are parallel to each other, one end of the first drive beam 26 is connected with the drive mass 5, the other end of the first drive beam 26 is connected with the support frame 4, one end of the second drive beam 27 is connected with the drive mass 5, the other end of the second drive beam 27 is connected with one end of the drive beam connecting block 28, the other end of the drive beam connecting block 28 is connected with the support frame 4, the thickness of the first drive beam 26 and the second drive beam 27 is the same as the thickness of the drive beam connecting block 28. When the microgyroscope is subjected to a driving force, the drive beam connecting block 28 is connected to the support frame 4 and plays a fixing role without movement, the first drive beam 26 and the second drive beam 27 are small in stiffness in the driving direction and are easy to bend, so that the drive mass 5 and the detection mass 6 are subjected to a driving force and occur stable amplitude oscillation in the driving direction.

[0053] As Figure 12 , 13 shown, the detection composite beam assembly includes a first detection composite beam 12, a second detection composite beam 13, a third detection composite beam 14 and a fourth detection composite beam 15, the first detection composite beam 12, the second detection composite beam 13, the third detection composite beam 14 and the fourth detection composite beam 15 are respectively arranged on the detection mass 6 close to the corners, the first detection composite beam 12, the second detection composite beam 13, the third detection composite beam 14 and the fourth detection composite beam 15 are the same in structure size and are all composed of a first detection beam 29, a second detection beam 30 and a detection beam connecting block 31, the detection beam connecting block 31 is provided with a protruding part on the two sides of one end and has a whole "T" shape, the first detection beam 29 and the second detection beam 30 are respectively located on the two sides of the detection beam connecting block 31 and are respectively connected with the protruding parts, the other end of the first detection beam 29 and the second detection beam 30 is connected with the detection mass 6, the other end of the detection beam connecting block 31 is connected with the drive mass 5. When there is a Z-axis angular rate input, the detection mass 6 occurs stable amplitude oscillation in the detection direction due to the Coriolis effect, the first detection beam 29 and the second detection beam 30 are bent, and the detection beam connecting block 31 is connected with the drive mass 5 and plays a fixing role.

[0054] AsFigure 14 、 15 As shown, the first detection beam 29 and the second detection beam 30 are slender beam structures, that is, the length of the beam is much greater than its width. The thickness of the first detection beam 29 and the second detection beam 30 is the same as the thickness of the detection beam connecting block 31. The difference is that the first driving combination beam 8, the second driving combination beam 9, the third driving combination beam 10, the fourth driving combination beam 11 and the first detection combination beam 12, the second detection combination beam 13, the third detection combination beam 14, and the fourth detection combination beam 15 are different in size. The size should be determined according to factors such as the stiffness and frequency of the actual micro gyroscope.

[0055] like Figure 16 As shown, the piezoelectric film driving electrode assembly includes: a first piezoelectric film driving electrode 22, a second piezoelectric film driving electrode 23, a third piezoelectric film driving electrode 24, and a fourth piezoelectric film driving electrode 25. The first piezoelectric film driving electrode 22, the second piezoelectric film driving electrode 23, the third piezoelectric film driving electrode 24, and the fourth piezoelectric film driving electrode 25 are respectively arranged on the first driving beam 26 at the four corners of the driving mass block 5. The first piezoelectric thin film driving electrode 22, the second piezoelectric thin film driving electrode 23, the third piezoelectric thin film driving electrode 24, and the fourth piezoelectric thin film driving electrode 25 have the same structure, and are all composed of a first piezoelectric driving top electrode 32, a second piezoelectric driving top electrode 33, a third piezoelectric driving top electrode 34, a fourth piezoelectric driving top electrode 35, a piezoelectric driving material layer 36, and piezoelectric driving bottom electrodes 16, 17, 18, and 19. The piezoelectric driving bottom electrodes 16, 17, 18, and 19 are placed on the first driving beam 26, and the piezoelectric driving material layer 36 is placed on the piezoelectric driving bottom electrode 16. The first piezoelectric driving top electrode 32, the second piezoelectric driving top electrode 33, the third piezoelectric driving top electrode 34, and the fourth piezoelectric driving top electrode 35 are respectively arranged at the four corners on the piezoelectric driving material layer 36, and gaps are left between them.

[0056] The piezoelectric driving bottom electrode 16 is a rectangular metal electrode plate with the same width as the piezoelectric driving material layer 36 and a greater length. There are four of these plates. The piezoelectric driving material layer 36 is a thin piezoelectric material film with a length significantly greater than its thickness and the same width as the bottom electrode plate. The polarization direction is perpendicular to the top and bottom surfaces of the structure.

[0057] The first piezoelectric film driving electrode 22 and the fourth piezoelectric film driving electrode 25 are respectively arranged on the upper and lower sides of the left side of the driving mass block 5, and the second piezoelectric film driving electrode 23 and the third piezoelectric film driving electrode 24 are respectively arranged on the upper and lower sides of the end of the driving mass block 5 opposite to the first piezoelectric film driving electrode 22.

[0058] The detection electrodes 20 are arranged respectively close to the second piezoelectric film driving electrode 23 and the third piezoelectric film driving electrode 24, and the signal detection lead 21 is drawn from the tunnel magnetoresistance element 7 and connected to the two detection electrodes 20.

[0059] The principle of the present application is as follows:

[0060] The micro-gyroscope device of the present application is driven by piezoelectric film driving electrodes, the polarization direction of the piezoelectric film is the thickness direction, and the transverse driving is realized by applying a vertical electric field through the piezoelectric film layer. The top electrodes of the piezoelectric film driving electrodes are divided into four parts, and different excitations are applied to these electrodes to realize the in-plane driving of the gyroscope device.

[0061] Taking the first piezoelectric film driving electrode 22 as an example, the piezoelectric driving bottom electrode 16 is grounded, the first piezoelectric driving top electrode 32 is connected to an alternating voltage, the second piezoelectric driving top electrode 33 and the fourth piezoelectric driving top electrode 35 are connected to an alternating voltage opposite to that of the first piezoelectric driving top electrode 32, the third piezoelectric driving top electrode 34 is connected to an alternating voltage same as that of the first piezoelectric driving top electrode 32, and the polarization direction of the piezoelectric material layer is the thickness direction. When the piezoelectric material under the first piezoelectric driving top electrode 32 and the third piezoelectric driving top electrode 34 is elongated under the action of the driving voltage, the driving material layer under the second piezoelectric driving top electrode 33 and the fourth piezoelectric driving top electrode 35 is shortened, and vice versa. The driving direction of the fourth piezoelectric film driving electrode 25 is the same as that of the first piezoelectric film driving electrode 22, and the driving directions of the second piezoelectric film driving electrode 23 and the third piezoelectric film driving electrode 24 are the same. In this way, reciprocating vibration in the transverse (X-axis) direction is realized. When there is an angular velocity input in the Z-axis direction, the detection mass 6 moves along the detection direction (Y-axis) under the action of the Coriolis force, the detection mass 6 drives the tunnel magnetoresistance element 7 to make steady amplitude oscillation above the detection magnet 2, so that the tunnel magnetoresistance element 7 is sensitive to the relatively large change of the magnetic field, thereby causing the spin-dependent tunneling current in the tunnel magnetoresistance element 7 to change, resulting in a dramatic change in the resistance value of the tunnel magnetoresistance element 7. The weak Coriolis force detection is realized by measuring the resistance value change.

[0062] The present application has the following advantages:

[0063] The present application adopts piezoelectric driving, tunnel magnetoresistance detection mode, solves the problems of weak driving capacity of the existing micro-mechanical gyroscope and difficult detection of weak Coriolis force, adopts piezoelectric driving mode, large driving displacement, small required driving voltage and low power consumption. When detecting, the magnetoresistance element with high sensitivity is used to detect the micro displacement caused by the Coriolis force, which is high in sensitivity, miniaturized and easy to detect. The in-plane detection micro-mechanical gyroscope has the advantages of small damping effect and high precision compared with the off-plane detection micro-mechanical gyroscope. Moreover, the micro-mechanical gyroscope of the present application adopts piezoelectric driving, which can provide a driving amplitude much larger than that provided by electrostatic driving. The purpose is to make the micro-gyroscope produce a larger Coriolis force under the Coriolis effect, and then produce a large amplitude stable oscillation in the detection direction, and at the same time, the tunnel magnetoresistance effect with high sensitivity is used for detection to improve the detection precision of the micro-gyroscope. The micro-gyroscope of the present application deposits high magnetic permeability soft magnetic material on the detection magnet, has a magnetic aggregation effect, realizes the enhancement of the local magnetic field strength to improve the magnetic field change rate, forms a stable high change rate magnetic field, and when the tunnel magnetoresistance element senses the change of the magnetic field, the resistance of the tunnel magnetoresistance element will change sharply under the weak magnetic field change. This change can improve the detection precision of the micro-gyroscope of the present application by one to two orders of magnitude. The micro-mechanical gyroscope of the present application has reasonable structure design, simple interface circuit and high detection precision, and can solve the problem of angular rate signal detection.

[0064] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the exemplary description of the above terms does not necessarily mean the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0065] Although the embodiments of the present application have been shown and described, those skilled in the art can understand that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and purposes of the present application, and the scope of the present application is defined by the claims and their equivalents.

Claims

1. A piezoelectrically driven tunneling magnetoresistive in-plane detected microgyroscope device comprising: A bonding substrate (1) and a support frame (4) arranged on the bonding substrate (1); a driving mass block (5) is arranged inside the support frame (4); a detection mass block (6) is arranged inside the driving mass block (5); corners of the driving mass block (5) are connected to the external support frame (4) through a driving composite beam assembly; corners of the detection mass block (6) are connected to the driving mass block (5) through a detection composite beam assembly; a tunnel magnetoresistive element (7) is arranged at the center of the detection mass block (6); and the invention is characterized in that: It also includes: a piezoelectric film drive electrode assembly and a detection electrode (20), wherein the piezoelectric film drive electrode assembly is arranged on the drive combination beam assembly, and the piezoelectric film drive electrode assembly includes a first piezoelectric film drive electrode (22), a second piezoelectric film drive electrode (23), a third piezoelectric film drive electrode (24), and a fourth piezoelectric film drive electrode (25), wherein the first piezoelectric film drive electrode (22), the second piezoelectric film drive electrode (23), the third piezoelectric film drive electrode (24), and the fourth piezoelectric film drive electrode (25) are respectively arranged on the drive combination beam assembly, and the detection electrode (20) is arranged at a position close to the second piezoelectric film drive electrode (23) and the third piezoelectric film drive electrode (24), and the tunnel magnetoresistive element (7) is respectively connected to the detection electrodes (20) via signal detection wires (21); The first piezoelectric film driving electrode (22), the second piezoelectric film driving electrode (23), the third piezoelectric film driving electrode (24), and the fourth piezoelectric film driving electrode (25) have the same structure and are composed of a first piezoelectric driving top electrode (32), a second piezoelectric driving top electrode (33), a third piezoelectric driving top electrode (34), a fourth piezoelectric driving top electrode (35), a piezoelectric driving material layer (36), and a piezoelectric driving bottom electrode (16, 17, 18, 19). The piezoelectric driving bottom electrodes (16, 17, 18, 19) are placed on the first driving beam (26), the piezoelectric driving material layer (36) is placed on the piezoelectric driving bottom electrode (16), and the first piezoelectric driving top electrode (32), the second piezoelectric driving top electrode (33), the third piezoelectric driving top electrode (34), and the fourth piezoelectric driving top electrode (35) are respectively arranged at four corners on the piezoelectric driving material layer (36), and gaps are left between them.

2. The piezoelectrically driven tunneling magnetoresistive in-plane detected microgyroscope device according to claim 1, characterized in that The driving combination beam assembly comprises a first driving combination beam (8), a second driving combination beam (9), a third driving combination beam (10), and a fourth driving combination beam (11), which are respectively arranged at four corners of the driving mass (5), and the first driving combination beam (8), the second driving combination beam (9), the third driving combination beam (10), and the fourth driving combination beam (11) are the same in structure and each comprise a first driving beam (26), a second driving beam (27), and a driving beam connecting block (28), the first driving beam (26) and the second driving beam (27) are respectively arranged on two sides of the driving beam connecting block (28) and are parallel to each other, one end of the first driving beam (26) is connected with the driving mass (5), the other end of the first driving beam (26) is connected with the support frame (4), one end of the second driving beam (27) is connected with the driving mass (5), the other end of the second driving beam (27) is connected with one end of the driving beam connecting block (28), and the other end of the driving beam connecting block (28) is connected with the support frame (4).

3. The piezoelectrically driven tunneling magnetoresistive in-plane detected microgyroscope device according to claim 1, characterized in that, The detection combination beam assembly comprises a first detection combination beam (12), a second detection combination beam (13), a third detection combination beam (14), and a fourth detection combination beam (15), which are respectively arranged at corners of the detection mass (6), and the first detection combination beam (12), the second detection combination beam (13), the third detection combination beam (14), and the fourth detection combination beam (15) are the same in structure and each comprise a first detection beam (29), a second detection beam (30), and a detection beam connecting block (31), the detection beam connecting block (31) is in the shape of "T" and is provided with a protruding part on each side of one end, the first detection beam (29) and the second detection beam (30) are respectively arranged on two sides of the detection beam connecting block (31) and are connected with the protruding parts, the other ends of the first detection beam (29) and the second detection beam (30) are connected with the detection mass (6), and the other end of the detection beam connecting block (31) is connected with the driving mass (5).

4. The piezoelectrically driven tunneling magnetoresistive in-plane detected microgyroscope device according to claim 1, characterized in that, The first piezoelectric film driving electrode (22), the second piezoelectric film driving electrode (23), the third piezoelectric film driving electrode (24), and the fourth piezoelectric film driving electrode (25) are respectively arranged on the first driving beam (26) at four corners of the driving mass (5).

5. The piezoelectrically driven tunneling magnetoresistive in-plane detected microgyroscope device according to claim 1, characterized in that, The bonding substrate (1) is in the shape of a square, a square groove is arranged in the center of the bonding substrate (1), a detection magnet (2) is arranged in the groove, the detection magnet (2) is arranged at the center of the bonding substrate (1), and a magnetic aggregation unit (3) is deposited on the detection magnet (2).

6. The piezoelectrically driven tunneling magnetoresistive in-plane detected microgyroscope device according to claim 5, characterized in that The detection magnet (2) comprises a permanent magnet, a coil, and a light-controlled magnet.

7. The piezoelectrically driven tunneling magnetoresistive in-plane detected microgyroscope device according to claim 5, characterized in that The shape of the magnetic concentrating unit (3) includes a triangle and a square.

8. The piezoelectrically driven tunneling magnetoresistive in-plane detected microgyroscope device according to claim 1, characterized in that, The external structure of the support frame (4) is square, and the size is consistent with the bonding substrate (1).

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