CN114034880A - Dynamic heat source type double-shaft micro-mechanical angular velocity sensor and processing method thereof - Google Patents
Dynamic heat source type double-shaft micro-mechanical angular velocity sensor and processing method thereof Download PDFInfo
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- CN114034880A CN114034880A CN202111387670.XA CN202111387670A CN114034880A CN 114034880 A CN114034880 A CN 114034880A CN 202111387670 A CN202111387670 A CN 202111387670A CN 114034880 A CN114034880 A CN 114034880A
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- G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
- G01P5/00—Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft
- G01P5/08—Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft by measuring variation of an electric variable directly affected by the flow, e.g. by using dynamo-electric effect
- G01P5/086—Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft by measuring variation of an electric variable directly affected by the flow, e.g. by using dynamo-electric effect by using special arrangements and constructions for measuring the dynamo-electric effect
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Abstract
The invention discloses a dynamic heat source type double-shaft micro-mechanical angular velocity sensor and a processing method thereof, wherein the double-shaft gyroscope comprises a substrate layer, a sensitive layer and a cover plate, the sensitive layer comprises a middle heating cavity and a middle detection cavity, and the upper surface of the sensitive layer is provided with an omnibearing vibrator heater (dynamic heat source) and two pairs of thermistors; the omnibearing vibrator heater (dynamic heat source) is suspended in the central position of the sensitive layer through six completely symmetrical semicircular supporting beams; the electrifying mode of the heater is periodic alternating current; the cover plate is etched with a groove and is hermetically connected with the upper surface of the sensitive layer. The invention can realize the measurement of biaxial angular velocity, has high sensitivity and fast response speed, has the characteristics of small structural stress, small volume, light weight, easy intellectualization and integration and the like, and conforms to the development direction of the sensor towards microminiature, synthesis and intelligence. Meanwhile, the vibration-proof and impact-proof steel plate has the advantages of simple structure and processing technology, extremely low cost, high reliability and excellent vibration-proof and impact-proof characteristics.
Description
Technical Field
The invention belongs to the technical field of detecting angular velocity attitude parameters of a moving body by utilizing a Coriolis force deflection omnibearing vibrator, in particular relates to a dynamic heat source type double-shaft micro-mechanical angular velocity sensor and a processing method thereof, and belongs to the field of inertia measurement.
Background
The Micro inertial sensor manufactured by using Micro-Electro-Mechanical-System (MEMS) technology has the advantages of mass production, low cost, small volume, low power consumption and the like, and is an ideal product of the future medium and low precision Micro inertial sensors. The gyroscope and the accelerometer are core inertial sensors for measuring and controlling the motion attitude of the carrier, and the gyroscope is a sensor sensitive to angular velocity, angular acceleration and other angular parameters. At present, the market has higher and higher requirements on the capability of a micro gyroscope to adapt to severe and harsh environments, and a micro fluid inertial sensor (MEMS inertial sensor) is unique in the MEMS sensor due to the ultra-high impact resistance and ultra-low manufacturing cost, and cannot be compared with other MEMS inertial sensors.
The micro fluid gyroscopes based on MEMS technology can be broadly classified into four types, namely micro fluidic gyroscopes, ECF (electro-coupled fluid) fluid gyroscopes, micro thermal convection gyroscopes and micro thermal flow gyroscopes. Chinese patent: a miniature four-channel circulating flow type three-axis silicon jet gyro (patent application number: 201510385582.4) belongs to a miniature jet gyro, a piezoelectric plate in a sensitive element of the miniature jet gyro increases processing difficulty and cost, and the volume of the miniature jet gyro is difficult to further reduce on the premise of keeping flow rate. ECF fluid gyroscopes are relatively large (40mm x 60mm x 7mm) and are difficult to commercialize in large volumes and at low cost because of the high kilovoltage required to form the liquid jet. The miniature thermal convection gyro cannot work without a gravity field, and the sensitivity is low. The above-described microfluidic gyros have their own inherent disadvantages that make them difficult to be the low-cost choice for commercial microfluidic gyros. The micro heat flow gyro (also called thermal expansion gyro) is a new micro fluid gyro which is proposed in recent years, a voltage-free electric sheet is not arranged in a sensitive element, high voltage is not required, and the micro heat flow gyro can be used in a gravity-free environment. Compared with the micro heat flow accelerometer (MEMS heat flow accelerometer) which is commercialized, the MEMS heat flow gyroscope is not mature yet and is still in a development stage. The difficulty of the MEMS heat flow gyroscope in practical application is that the sensitivity is lower than that of a micromechanical vibration gyroscope. In chinese patents 201410140298.6 and 201210130318.2, micromechanical heat-flow gyroscopes almost all use a heater to generate a thermal expansion flow that is deflected by coriolis force when an angular velocity is input, and a symmetrical thermistor is provided to detect an asymmetric distribution of a temperature field. Because the velocity of hot air flow is very small, the gradient of asymmetric temperature field caused by deflection of air flow is very small, so that the unbalanced voltage output by the Wheatstone bridge formed by the thermistor is small, and the sensitivity of the sensor is low. In the conventional solution, although the sensitivity can be improved by increasing the heater power, the sensitivity is not substantially changed or improved due to the limitation of power consumption, and the bottleneck of practical use is difficult to break through.
Disclosure of Invention
The invention aims to provide a dynamic heat source type double-shaft micro-mechanical angular velocity sensor, which aims to solve the technical problems in the prior art.
In order to achieve the purpose, the invention adopts the following technical scheme:
the invention provides a dynamic heat source type double-shaft micro-mechanical angular velocity sensor, which comprises a substrate layer, a sensitive layer and a cover plate, wherein,
the sensing layer comprises a middle heating cavity and a middle detection cavity, and the upper surface of the sensing layer is provided with an omnibearing vibrator heater (a dynamic heat source) and two pairs of thermistors;
defining the length direction of the upper surface of the sensitive layer as an X direction, the width direction as a Y direction and the height direction as a Z direction; the arrangement directions of the two pairs of thermistors are the X direction and the Y direction, and each pair of thermistors are parallel to each other and are used for detecting the angular speeds of the X axis and the Y axis;
the omnibearing vibrator heater (dynamic heat source) adopts a wind-fire wheel type sensitive structure, the center of the omnibearing vibrator heater comprises a central wheel hub with a round mass block, and the omnibearing vibrator heater is suspended in the central position of a sensitive layer through six completely symmetrical semi-circles, which are also called supporting beams; a circular middle heating cavity is arranged below the heating cavity;
the omnibearing vibrator heater (dynamic heat source) can swing along a z axis vertical to the sensitive layer and also can swing along any azimuth angle in an XOY plane where the sensitive layer is located;
two ends of the omnidirectional vibrator heater are covered with symmetrical electrodes along the Y direction to form a movable resistance type heat source;
the thermistor comprises a pair of thermistors for detecting the angular velocity of an X axis and a pair of thermistors for detecting the angular velocity of a Y axis, and a rectangular middle detection cavity is arranged below the thermistors;
a pair of thermistors for detecting the angular velocity of the X axis are symmetrically arranged along the Y axis direction and are vertical to the X axis direction; a pair of thermistors for detecting the angular velocity of the Y axis are symmetrically arranged along the X axis direction and are vertical to the Y axis direction;
the omnibearing vibrator heater is electrified by periodic alternating current to generate alternating excitation voltage; the power-on mode of the thermistor is constant current;
and the cover plate is etched with a groove and is hermetically connected with the upper surface of the sensitive layer.
The cover plate and the basal layer isolate the gas media of the intermediate heating cavity and the intermediate detection cavity from the outside to form a sealed working system; the heights of the middle heating cavity and the middle detection cavity and the depth of the groove in the upper sealing layer are the total cavity height z, and z is more than or equal to 300 mu m and less than or equal to 1000 mu m;
as a further technical solution, the depth of the groove of the cover plate is 2/3 of the height of the cover plate.
As a further technical scheme, the height of the omnidirectional vibrator heater and the thermistor is 100nm to 1000 nm.
As a further technical scheme, the two pairs of thermistors are consistent in length and are 1/6-1/5 of the width of the whole sensitive layer.
As a further technical scheme, the heater and the thermistor are both composed of metal layers consisting of a chromium adhesion layer and a platinum layer.
A method for processing a dynamic heat source type double-shaft micro-mechanical angular velocity sensor comprises the following specific process flows:
the method comprises the following steps: thermally oxidizing a 0.5 μm thick silicon dioxide film on an N-type (100) single crystal silicon wafer;
step two: photoetching the silicon dioxide film to form an omnidirectional oscillator heater and thermistor structural pattern;
step three: sputtering a metal layer consisting of a chromium adhesion layer and a platinum layer on the photoresist and the silicon dioxide in sequence by a magnetron sputtering process;
step four: stripping off the metal layer outside the omnibearing vibrator heater and the thermistor structure pattern by adopting an ultrasonic stripping process to form an omnibearing vibrator heater and a thermistor structure;
step five: etching off a part of silicon dioxide by adopting photoetching and wet etching processes;
step six: a groove with the depth of 300 mu m is formed by corrosion processing by adopting a silicon etching process, so that the omnibearing vibrator heater and the thermistor are suspended and fixed on the sensitive layer through the silicon dioxide film to complete the processing of the gyroscope sensitive layer;
step seven: the cover plate and the sensitive layer are bonded through a bonding process, so that the upper surface of the sensitive layer is positioned in the closed cavity to complete the processing of the gyroscope sensitive element, and the dynamic heat source type double-shaft micro-mechanical angular velocity sensor is formed.
By adopting the technical scheme, the invention has the following beneficial effects:
1. the dynamic heat source type double-shaft micro-mechanical angular velocity sensor inherits the advantages of an MEMS heat flow gyroscope, and is small in size, light in weight and easy to intelligentize and integrate.
2. The sensitive structure of the gyroscope is a middle omnidirectional oscillator heater (dynamic heat source). The omnidirectional vibrator has freedom of inertial force at any azimuth angle on the rotation plane except for vibrating along the z-axis perpendicular to the rotation plane. The sensitive structure is suspended at the center of the sensitive layer through six completely symmetrical semicircular supporting beams, and can sense the input angular speed of a rotating shaft (sensitive shaft) along any azimuth angle of an X axis or a Y axis in an XOY plane, so that the measurement of the biaxial angular speed is realized, the sensitivity is high, and the response speed is high.
3. The omnidirectional vibrator adopts a wind-fire wheel type sensitive structure, a central wheel hub is a mass block and is also a heater, and the mass block is suspended on the plane of the vibrator through a plurality of completely symmetrical high-elasticity semicircular supporting beams. The sensitive structure of the wind-fire wheel type has the following advantages: the sensitive structure is adopted for central support, so that the structural stress is small; the structure symmetry is high, and the consistency of azimuth detection can be realized; the wind-fire wheel type sensitive structure can realize that a relatively long elastic element and a relatively large mass block are manufactured in a small area, so that high inertia force sensitivity is obtained.
4. The sensitive element is made on a silicon chip by the processes of photoetching, corrosion and the like, has good consistency, is convenient for introducing a microcomputer embedded system (singlechip) to carry out temperature compensation and nonlinear degree compensation, not only can improve the performance of the sensor, but also can realize batch production.
5. The micro-gyroscope has the advantages of simple structure and processing technology, extremely low cost, high reliability and excellent vibration and impact resistance, so that the micro-gyroscope can compete with a capacitive micro-mechanical vibration gyroscope in the micro-gyroscope market with medium, low precision and low price.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.
FIG. 1 is a schematic three-dimensional structure diagram of a sensitive layer provided in an embodiment of the present invention;
fig. 2 is a schematic three-dimensional structure diagram of a cover plate according to an embodiment of the present invention;
FIG. 3 is a top view of a sensitive layer provided by an embodiment of the present invention;
FIG. 4 is a sectional view taken along line A-A of FIG. 3;
FIG. 5 is a schematic diagram of the operation of the present invention;
FIG. 6 is a schematic diagram of an output circuit provided by an embodiment of the invention;
fig. 7 is a flow chart of a manufacturing process of a dynamic heat source type dual-axis micro-mechanical angular velocity sensor according to an embodiment of the present invention;
icon: 1-basal layer, 2-sensitive layer, 3-middle detection cavity, 4-middle heating cavity, 5-cover plate, 6-groove, 7-omnibearing vibrator heater, 8-thermistor, 9-thermistor, 10-thermistor, 11-thermistor, 12-metal electrode.
Detailed Description
The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
The following detailed description of embodiments of the invention refers to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.
With reference to fig. 1-4, the present embodiment provides a dynamic heat source type two-axis micromechanical sensor of angular velocity, comprising a substrate 1, a sensitive layer 2 and a cover plate 5, wherein,
the sensitive layer 2 comprises an intermediate heating cavity 4 and an intermediate detection cavity 3, and the upper surface of the sensitive layer is provided with an omnibearing vibrator heater 7 and two pairs of thermistors;
defining the length direction of the upper surface of the sensitive layer as an X direction, the width direction as a Y direction and the height direction as a Z direction; the arrangement directions of the two pairs of thermistors are the X direction and the Y direction, and each pair of thermistors are parallel to each other and are used for detecting the angular speeds of the X axis and the Y axis;
the omnibearing vibrator heater 7 adopts a wind-fire wheel type sensitive structure, the center of the omnibearing vibrator heater comprises a central wheel hub with a circular mass block, and the omnibearing vibrator heater is suspended at the central position of a sensitive layer through six completely symmetrical semicircular supporting beams; a circular middle heating cavity 4 is arranged below the heating cavity;
the omnidirectional oscillator heater 7 can swing along any azimuth angle in an XOY plane of the sensitive layer besides the z axis vertical to the sensitive layer.
Two ends of the omnidirectional vibrator heater are covered with symmetrical metal electrodes 12 along the Y direction to form a movable resistance type heat source;
the thermistor comprises a pair of thermistors (a thermistor 8 and a thermistor 10) for detecting the angular velocity of an X axis and a pair of thermistors (a thermistor 9 and a thermistor 11) for detecting the angular velocity of a Y axis, and a rectangular middle detection cavity 3 is arranged below the thermistors;
a thermistor 8 and a thermistor 10 for detecting the angular velocity of the X axis are arranged on two sides of the upper surface of the sensitive layer in the Y direction in parallel, and a thermistor 9 and a thermistor 11 for detecting the angular velocity of the Y axis are arranged on two sides of the upper surface of the sensitive layer in the X direction in parallel;
the omnibearing vibrator heater 7 is electrified by periodic alternating current to generate alternating excitation voltage; the power-on mode of the thermistor is constant current;
a groove 6 is etched in the cover plate 5 and is hermetically connected with the upper surface of the sensitive layer 2;
in this embodiment, as a further technical solution, the omnidirectional oscillator heater 7 can sense the input angular velocity of the rotating shaft (sensing axis) along any azimuth angle of the X axis or the Y axis in the XOY plane, so as to realize the measurement of the biaxial angular velocity.
In the embodiment, as a further technical scheme, the omnidirectional oscillator heater 7 is driven by alternating excitation voltage to generate an alternating temperature field, the oscillator generates alternating thermal stress along the axial direction and the thickness direction of the oscillator, and meanwhile, the oscillator is electrified to generate joule heat to release heat to surrounding gas for heat diffusion to form heat flow. When the frequency of the alternating current excitation signal is consistent with the vibration frequency of the vibrator along the X axis (Y axis), the vibrator resonates in the X axis (Y axis) direction to generate displacement, and the heat flow is driven to flow in the X axis (Y axis) direction.
The operation of the sensor is divided into two cases, as shown in connection with fig. 5. When the angular velocity omega is inputted in the X-axis directionXBecause of the Coriolis force principle, the omnidirectional oscillator heater 7 deflects the thermistor 8 or 10 in the YOX plane in the Y-axis direction, and the temperature of the thermistor with deflected thermal oscillator is higher than that of the thermistor parallel to the thermistor, so that the two parallel thermistors 8 and 10 generate the angular velocity omega equal to the input angular velocityXA proportional temperature difference. The thermistor 8 and the thermistor 10 are connected in two equal legs of a two wheatstone bridge as shown in fig. 6. When the angular velocity omega is inputted in the Y-axis directionYBecause of the Coriolis force principle, the omnidirectional oscillator heater 7 deflects the thermistor 9 or 11 in the YOX plane in the X-axis direction, and the temperature of the thermistor in which the thermal oscillator is deflected is higher than that of the thermistor parallel to the thermistor, so that the two parallel thermistors 9 and 11 generate an angular velocity omega with the input angular velocityYA proportional temperature difference. In the figure, Tx1 corresponds to the thermistor 9, Tx2 corresponds to the thermistor 11, Ty1 corresponds to the thermistor 8, and Ty2 corresponds to the thermistor 10.
The thermistor 9 and the thermistor 11 are connected in two equal legs of two wheatstone bridges, as shown in fig. 6. The temperature difference generated by the input angular velocity is converted into the angular velocity omega through the change of the resistance of the bridge arm of the Wheatstone bridge shown in FIG. 6XOr ΩYProportional unbalanced voltage VXOr VYThereby sensing an angle in the X or Y directionThe speed is that a dynamic heat source type double-shaft micro-mechanical angular speed sensor is formed.
In the embodiment, as a further technical scheme, the cover plate 5 and the substrate layer 1 isolate the gas media of the intermediate heating cavity 4 and the intermediate detection cavity 3 from the outside to form a sealed working system; the height of the middle heating cavity 4 and the middle detection cavity 3 and the depth of the groove 6 in the upper sealing layer are the total cavity height z, and z is more than or equal to 300 mu m and less than or equal to 1000 mu m; the total cavity height in the embodiment is hundreds of microns, so that natural convection motion of gas flow in the cavity can be effectively inhibited, and the influence of Z-axis acceleration on the performance of the sensor can be greatly reduced. The total cavity height may be arbitrarily selected in the range of 300 microns to 1000 microns, depending on the requirements for gyroscope performance, for example the total cavity height in the above embodiment may be 700 microns.
In this embodiment, as a further technical solution, in order to increase the depth of the cover plate groove, the gas flowing space can be increased, thereby increasing the sensitivity of the sensor, and the depth of the groove 6 is 2/3 of the height of the cover plate 5.
In this embodiment, as a further technical solution, in order to form a more stable and reliable thin film resistor having a resistance value with a small change with temperature, the heights of the heater and the thermistor on the upper surface of the sensitive layer are 100nm to 1000 nm.
In this embodiment, as a further technical solution, to increase the stability and shock resistance of the sensor, the two pairs of thermistors have the same length, which is 1/6 to 1/5 of the width of the whole sensitive layer.
In this embodiment, as a further technical solution, the heater and the thermistor are each formed by a metal layer composed of a chromium adhesion layer and a platinum layer.
Referring to fig. 7, the dynamic heat source type dual-axis micro-mechanical angular velocity sensor disclosed by the present invention has the following manufacturing process:
step (a): a0.5 μm thick silicon dioxide film was thermally oxidized on an N-type (100) single crystal silicon wafer, as shown in FIG. 7 (a).
Step (b): the omnidirectional oscillator heater and thermistor structure pattern is formed on the silicon dioxide film by photolithography, as shown in fig. 7 (b).
Step (c): a metal layer consisting of a chromium adhesion layer and a platinum layer was sequentially sputtered on the photoresist and the silicon dioxide by a magnetron sputtering process, as shown in fig. 7 (c).
Step (d): and (d) stripping off the metal layer except the omnibearing vibrator heater and thermistor structure pattern by adopting an ultrasonic stripping process, and forming the omnibearing vibrator heater and thermistor structure as shown in fig. 7 (d).
A step (e): a portion of the silicon dioxide is etched away using photolithography and wet etch processes, as shown in fig. 7 (e).
Step (f): and (3) corroding and processing by adopting a silicon etching process to form a groove with the depth of 300 microns, so that the omnibearing vibrator heater and the thermistor are fixed on the sensitive layer in a suspended manner through the silicon dioxide film, and the processing of the gyroscope sensitive layer is finished, as shown in fig. 7 (f).
Step (g): the cover plate and the sensitive layer are bonded through a bonding process, so that the upper surface of the sensitive layer is positioned in the closed cavity to complete the processing of the gyroscope sensitive element, and the dynamic heat source type double-shaft micro-mechanical angular velocity sensor is formed.
In summary, the invention breaks through the inherent mode of the previous research on the heat flow gyroscope, and provides a dynamic heat source type double-shaft micro-mechanical angular velocity sensor, which enables a heater with a very high temperature gradient to move, enables the heater to deflect under the action of inertia force to form a large temperature gradient at a thermistor, and thus realizes high-sensitivity output. The omnibearing vibrator heater (dynamic heat source) is suspended in the center of the sensitive layer through six completely symmetrical semi-circular support beams, can realize double-shaft angular velocity measurement, and has high sensitivity and high response speed. The wind-fire wheel type sensitive structure has high structural symmetry and small structural stress, and can ensure the consistency of azimuth angle detection. The structure can realize that a relatively long elastic element and a relatively large mass block are manufactured in a small area, so that high inertia force sensitivity is obtained. The sensitive element is made on a silicon chip by the processes of photoetching, corrosion and the like, has good consistency, is convenient for introducing a microcomputer embedded system (singlechip) to carry out temperature compensation and nonlinear degree compensation, not only can improve the performance of the sensor, but also can realize batch production. The dynamic heat source type double-shaft micro-mechanical angular velocity sensor not only inherits the advantages of an MEMS heat flow gyroscope, but also has the characteristics of simple structure, small volume, light weight, easy intellectualization and integration and the like, and accords with the development direction of the sensor towards microminiature, synthesis and intelligence. Meanwhile, the micro-gyroscope has the advantages of simple structure and processing technology, extremely low cost, high reliability and excellent vibration and impact resistance, so that the micro-gyroscope can compete with a capacitive micro-mechanical vibration gyroscope in the micro-gyroscope market with medium, low precision and low price.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.
Claims (7)
1. A dynamic heat source type double-shaft micro-mechanical angular velocity sensor is characterized by comprising a substrate layer, a sensitive layer and a cover plate, wherein,
the sensing layer comprises a middle heating cavity and a middle detection cavity, and the upper surface of the sensing layer is provided with an omnibearing vibrator heater and two pairs of thermistors;
defining the length direction of the upper surface of the sensitive layer as an X direction, the width direction as a Y direction and the height direction as a Z direction; the arrangement directions of the two pairs of thermistors are the X direction and the Y direction, and each pair of thermistors are parallel to each other and are used for detecting the angular speeds of the X axis and the Y axis;
the omnibearing vibrator heater adopts a wind-fire wheel type sensitive structure, the center of the omnibearing vibrator heater comprises a central wheel hub with a circular mass block, and the omnibearing vibrator heater is suspended at the central position of a sensitive layer through six completely symmetrical semicircular supporting beams; a circular middle heating cavity is arranged below the heating cavity;
the omnidirectional oscillator heater can swing along a z axis vertical to the sensitive layer and also can swing along any azimuth angle in an XOY plane where the sensitive layer is located;
two ends of the omnidirectional vibrator heater are covered with symmetrical electrodes along the Y direction to form a movable resistance type heat source;
the thermistor comprises a pair of thermistors for detecting the angular velocity of an X axis and a pair of thermistors for detecting the angular velocity of a Y axis, and a rectangular middle detection cavity is arranged below the thermistors;
a pair of thermistors for detecting the angular velocity of the X axis are symmetrically arranged along the Y axis direction and are vertical to the X axis direction; a pair of thermistors for detecting the angular velocity of the Y axis are symmetrically arranged along the X axis direction and are vertical to the Y axis direction;
the omnibearing vibrator heater is electrified by periodic alternating current to generate alternating excitation voltage; the power-on mode of the thermistor is constant current;
and the cover plate is etched with a groove and is hermetically connected with the upper surface of the sensitive layer.
2. The dynamic heat source type biaxial micromechanical angular velocity sensor according to claim 1, wherein the cover plate and the substrate layer isolate the gas media of the intermediate heating cavity and the intermediate detection cavity from the outside to form a sealed working system; the height of the middle heating cavity and the middle detection cavity and the depth of the groove in the cover plate are the total cavity height z, and z is more than or equal to 300 mu m and less than or equal to 1000 mu m.
3. The dynamic heat source type two-axis micromechanical sensor of angular velocity according to claim 1, wherein the groove depth of the cover plate is 2/3 of the cover plate height.
4. The dynamic heat source type biaxial micromachined angular velocity sensor of claim 1, wherein the height of the omnidirectional vibrator heater and the thermistor is 100nm to 1000 nm.
5. The dynamic heat source type biaxial micromachined angular velocity sensor of claim 1, wherein the heater and the thermistor have the same length, each 1/6 to 1/5 of the entire width of the sensing layer.
6. The dynamic heat source type biaxial micromachined angular velocity sensor of claim 1, wherein the heater and the thermistor are each composed of a metal layer composed of a chromium adhesion layer and a platinum layer.
7. A method for processing the dynamic heat source type biaxial micromechanical angular velocity sensor according to any one of claims 1 to 6, characterized in that the specific process flow is as follows:
the method comprises the following steps: thermally oxidizing a 0.5 μm thick silicon dioxide film on an N-type (100) single crystal silicon wafer;
step two: photoetching the silicon dioxide film to form an omnidirectional oscillator heater and thermistor structural pattern;
step three: sputtering a metal layer consisting of a chromium adhesion layer and a platinum layer on the photoresist and the silicon dioxide in sequence by a magnetron sputtering process;
step four: stripping off the metal layer outside the omnibearing vibrator heater and the thermistor structure pattern by adopting an ultrasonic stripping process to form an omnibearing vibrator heater and a thermistor structure;
step five: etching off a part of silicon dioxide by adopting photoetching and wet etching processes;
step six: a groove with the depth of 300 mu m is formed by corrosion processing by adopting a silicon etching process, so that the omnibearing vibrator heater and the thermistor are suspended and fixed on the sensitive layer through the silicon dioxide film to complete the processing of the gyroscope sensitive layer;
step seven: the cover plate and the sensitive layer are bonded through a bonding process, so that the upper surface of the sensitive layer is positioned in the closed cavity to complete the processing of the gyroscope sensitive element, and the dynamic heat source type double-shaft micro-mechanical angular velocity sensor is formed.
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