CN113985071A - Omnidirectional dynamic heat source pendulum type double-shaft micro mechanical accelerometer and processing method thereof - Google Patents
Omnidirectional dynamic heat source pendulum type double-shaft micro mechanical accelerometer and processing method thereof Download PDFInfo
- Publication number
- CN113985071A CN113985071A CN202111410353.5A CN202111410353A CN113985071A CN 113985071 A CN113985071 A CN 113985071A CN 202111410353 A CN202111410353 A CN 202111410353A CN 113985071 A CN113985071 A CN 113985071A
- Authority
- CN
- China
- Prior art keywords
- heat source
- heater
- sensitive layer
- omnidirectional
- axis
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
- G01P15/00—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration
- G01P15/02—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses
- G01P15/08—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values
- G01P15/12—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values by alteration of electrical resistance
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Pressure Sensors (AREA)
- Micromachines (AREA)
Abstract
The invention discloses an omnidirectional dynamic heat source pendulum type double-shaft micro mechanical accelerometer and a processing method thereof, wherein the double-shaft accelerometer 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 omnidirectional dynamic heat source pendulum heater and two pairs of thermistors; the omnidirectional moving heat source swinging heater is suspended at the central position of the sensitive layer through six completely symmetrical semicircular supporting beams; the electrifying mode of the heater is constant 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 the biaxial acceleration, has the characteristics of high sensitivity, high response speed, small structural stress, 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 structure and the processing technology are very simple, the cost is extremely low, the reliability is high, and the vibration and impact resistance is excellent.
Description
Technical Field
The invention relates to the technical field of detecting acceleration attitude parameters of a motion carrier by utilizing the swing of an omnidirectional moving heat source pendulum under the action of linear acceleration, in particular to an omnidirectional moving heat source pendulum type double-shaft micro-mechanical accelerometer and a processing method thereof, and belongs to the field of inertia measurement.
Background
Due to the application requirements of the carrier attitude measurement in various fields of civil vehicles, railway construction, industrial production, bridge construction, seismic research, geodetic surveying, geological exploration, marine investigation, satellite communication, robot engineering and the like, in recent years, the organic combination between the sensor technology and the emerging scientific technology enables the attitude sensor to develop towards microminiature, comprehensive and intelligent. 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 accelerometer is a core inertial sensor for measuring and controlling the motion attitude of the carrier.
The most common among accelerometers is the pendulum acceleration sensor. The pendulum tilt sensor commonly used at present has three types, namely a liquid pendulum type sensor, a solid pendulum type sensor and a heat flow type sensor. The solid pendulum type tilt angle sensor has the advantages of complex structure, high cost, large motion amplitude of the solid pendulum and difficulty in bearing high overload or impact. The main problems of the liquid pendulum tilt angle sensor are that the number of structural components is large, the response time is long, and the performance changes greatly along with the temperature. The heat flow type accelerometer has the characteristics of small sensitive mass, simple structure, high overload bearing capacity, short response time, good temperature performance, low cost and the like, and can be applied to severe environments. At present, the requirement of the market on the capability of the micro accelerometer to adapt to the harsh environment is higher and higher, so that in the micro acceleration sensor, the micro mechanical system (MEMS) heat flow acceleration is unique in the MEMS sensor by the ultra-high impact resistance and ultra-low manufacturing cost, and cannot be compared with other MEMS accelerometers.
The working principle of the micro-mechanical (MEMS) heat flow accelerometer is as follows: the resistance heater is arranged in the closed cavity, the parallel detection thermistors are symmetrically distributed around the resistance heater, the resistance heater is electrified and heated to form a heat source to emit heat flow to the periphery, and the temperature fields are symmetrically distributed, so that the influence on the thermistors is consistent. When the external wired acceleration is input, the flowing direction of hot air flow is the same as the acceleration direction, and the hot air flow changes towards the input acceleration direction, so that the temperature field of the air flow is asymmetrically distributed, the temperature changes of two adjacent detection thermistors in the same direction are opposite, and the two detection thermistors generate temperature difference. The acceleration can be detected by detecting the temperature difference through the Wheatstone bridge. Chinese patent: in the micro silicon bridge type thermal convection acceleration sensor (patent application No. 02116842.3), the micro heat flow accelerometer of the Chinese patent and the manufacturing method thereof (patent application No. 03143287.6), the heater generates heat flow to move under the action of the acceleration of an input line, so that an asymmetric temperature field is generated, and the asymmetric distribution of the temperature field is detected by arranging symmetrical thermistors. 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 an omnidirectional dynamic heat source pendulum type double-shaft micromechanical accelerometer 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 an omnidirectional dynamic heat source pendulum type double-shaft micromechanical accelerometer, which comprises a substrate layer, a sensitive layer and a cover plate, wherein,
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 omnidirectional movable heat source swinging 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 acceleration of the X axis and the acceleration of the Y axis;
the omnidirectional dynamic heat source swing heater adopts a wind-fire wheel type sensitive structure, the center of the omnidirectional dynamic heat source swing heater contains a center wheel hub with a round mass block, and the omnidirectional dynamic heat source swing heater is suspended at the center position of a sensitive layer through six completely symmetrical semi-circles, also called supporting beams; a circular middle heating cavity is arranged below the heating cavity;
the omnidirectional moving heat source pendulum 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 moving heat source pendulum heater are covered with symmetrical electrodes along the Y direction to form a moving resistance type heat source;
the thermistor comprises a pair of thermistors for detecting X-axis acceleration and a pair of thermistors for detecting Y-axis acceleration, and a rectangular middle detection cavity is arranged below the thermistors;
a pair of thermistors for detecting the acceleration of the X axis are symmetrically arranged along the direction of the Y axis and are vertical to the direction of the X axis; a pair of thermistors for detecting the acceleration of the Y axis are symmetrically arranged along the direction of the X axis and are vertical to the direction of the Y axis;
the power-on modes of the omnidirectional moving heat source pendulum heater and the thermistor are 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 height 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 dynamic heat source pendulum 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 an omnidirectional dynamic heat source pendulum type double-shaft micromechanical accelerometer 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 structural patterns of an omnidirectional dynamic heat source pendulum heater and a thermistor;
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 all-directional movable heat source pendulum heater and the thermistor structure pattern by adopting an ultrasonic stripping process to form an all-directional movable heat source pendulum 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 omnidirectional moving heat source pendulum heater and the thermistor are suspended and fixed on the sensitive layer through a silicon dioxide film to complete the processing of the sensitive layer of the accelerometer;
step seven: and bonding the cover plate and the sensitive layer by a bonding process to enable the upper surface of the sensitive layer to be positioned in the closed cavity to complete the processing of the sensitive element of the accelerometer, thereby forming the omnidirectional moving heat source pendulum type double-shaft micro mechanical accelerometer.
By adopting the technical scheme, the invention has the following beneficial effects:
1. the omnidirectional dynamic heat source pendulum type double-shaft micro mechanical accelerometer inherits the advantages of an MEMS heat flow accelerometer, and is small in size, light in weight and easy to intelligentize and integrate.
2. The sensitive structure of the accelerometer is a middle omnidirectional dynamic heat source pendulum heater. The omnibearing pendulum has inertial freedom (oscillation) in any azimuth angle on the XOY plane of the sensitive layer except that it can oscillate up and down along the z-axis perpendicular to the plane of the sensitive layer. The sensitive structure is suspended at the center of the sensitive layer through six completely symmetrical semicircular supporting beams, and can sense the input acceleration along the X axis or the Y axis, so that the measurement of the biaxial acceleration is realized, the sensitivity is high, and the response speed is high.
3. The omnidirectional vibrator adopts a wind-fire wheel type sensitive structure, and a central wheel hub is a mass block and is also a heater. 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 structure and the processing technology are very simple, the cost is extremely low, the reliability is high, and the vibration and impact resistance is excellent.
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 the omnidirectional dynamic heat source pendulum type dual-axis micro mechanical accelerometer according to the embodiment of the invention;
icon: 1-basal layer, 2-sensitive layer, 3-middle detection cavity, 4-middle heating cavity, 5-cover plate, 6-groove, 7-omnibearing movable heat source pendulum heater, 8-thermistor, 9-thermistor, 10-thermistor, 11-thermistor and 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.
Referring to fig. 1-4, the present embodiment provides an omnidirectional moving heat source pendulum type dual-axis micro mechanical accelerometer, which includes 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 omnidirectional movable heat source pendulum 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 acceleration of the X axis and the acceleration of the Y axis; the omnidirectional dynamic heat source swing heater 7 adopts a wind-fire wheel type sensitive structure, the center of the omnidirectional dynamic heat source swing heater comprises a central wheel hub with a circular mass block, and the omnidirectional dynamic heat source swing 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 moving heat source pendulum heater 7 can swing along any azimuth angle in an XOY plane where the sensitive layer is positioned besides the z axis vertical to the sensitive layer.
Two ends of the omnidirectional moving heat source pendulum heater are covered with symmetrical metal electrodes 12 along the Y direction to form a moving resistance type heat source;
the thermistor comprises a pair of thermistors (a thermistor 8 and a thermistor 10) for detecting X-axis acceleration and a pair of thermistors (a thermistor 9 and a thermistor 11) for detecting Y-axis acceleration, and a rectangular middle detection cavity 3 is arranged below the thermistors;
a thermistor 8 and a thermistor 10 for detecting the acceleration 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 acceleration of the Y axis are arranged on two sides of the upper surface of the sensitive layer in the X direction in parallel;
the power-on modes of the omnidirectional moving heat source pendulum heater 7 and the thermistor are 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 the embodiment, as a further technical scheme, the omnidirectional moving heat source pendulum heater 7 can sense the input acceleration along any azimuth angle of the X axis or the Y axis in the XOY plane, so that the measurement of the biaxial acceleration is realized.
In this embodiment, as a further technical solution, the omnidirectional dynamic heat source pendulum heater 7 is energized with a constant current, the resistance heater is energized to generate joule heat, and releases heat to the surrounding air to perform heat diffusion, and a heat flow is formed around the resistance heater, and a temperature field generated by the heat flow is symmetrically distributed between two thermistors (thermistor 8 and thermistor 10 or thermistor 9 and thermistor 11) in two same directions.
As shown in connection with FIG. 5, when the input is along the X or Y axis linear acceleration input aXOr aYWhen the omnidirectional movable heat source pendulum 7 moves along the direction same as the acceleration direction under the action of the acceleration, the temperature field generated by hot air flow is asymmetrically distributed, the temperature changes of two adjacent thermistors 8 and 10 or 9 and 11 in the same direction are opposite, the temperature of the thermistor deflected by the omnidirectional movable heat source pendulum is higher than that of the thermistor parallel to the thermistors, and the temperature difference is generated between the two adjacent thermistors 8 and 10 or 9 and 11. 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.
As shown in FIG. 6, the thermistor 8 and the thermistor 10 or the thermistor 9 and the thermistor 11 are used as two arms of a Wheatstone bridge, and the temperature difference caused by the acceleration of the input line is converted into a change in the resistance of the arms by the thermal resistance effect, thereby causing a bridge unbalanced voltage V proportional to the input accelerationXOr VY. The linear acceleration of the X/Y axis can be calculated according to the output voltage, so that the acceleration in the X or Y direction is sensitive, and an omnidirectional moving heat source pendulum type double-axis micromechanical accelerometer 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, the height of the heater and the thermistor on the upper surface of the sensitive layer is 100nm to 1000nm, so as to form a more stable and reliable thin film resistor with resistance value having small variation with temperature.
In this embodiment, as a further technical solution, the lengths of the two pairs of thermistors are consistent, and are 1/6 to 1/5 of the width of the whole sensitive layer, so as to increase the stability and the shock resistance of the sensor.
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 manufacturing process of the omnidirectional moving heat source pendulum type dual-axis micro mechanical accelerometer disclosed by the invention is as follows:
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 silicon dioxide film is photoetched to form a structural pattern of the omnidirectional moving heat source pendulum heater and the thermistor, 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 outside the structure patterns of the omnidirectional moving heat source pendulum heater and the thermistor by adopting an ultrasonic stripping process, and forming the omnidirectional moving heat source pendulum heater and the 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) forming a groove with the depth of 300 microns by adopting a silicon etching process, suspending and fixing the omnidirectional moving heat source pendulum heater and the thermistor on the sensitive layer through a silicon dioxide film, and finishing the processing of the sensitive layer of the accelerometer, as shown in fig. 7 (f).
Step (g): and bonding the cover plate and the sensitive layer by a bonding process to enable the upper surface of the sensitive layer to be positioned in the closed cavity to complete the processing of the sensitive element of the accelerometer, thereby forming the omnidirectional moving heat source pendulum type double-shaft micro mechanical accelerometer.
In summary, the invention breaks through the inherent mode of the previous research on the heat flow accelerometer, and provides the omnidirectional moving heat source pendulum type double-shaft micro mechanical accelerometer, so that the heater with a very high temperature gradient moves, the heater deflects under the action of the inertia force to form a large temperature gradient at the thermistor, and the output with high sensitivity is realized. The omnidirectional dynamic heat source pendulum heater is suspended at the center of a sensitive layer through six completely symmetrical semicircular supporting beams, can realize the measurement of biaxial acceleration, 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 omnidirectional dynamic heat source pendulum type double-shaft micro mechanical accelerometer not only inherits the advantages of an MEMS heat flow accelerometer, 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 a sensor towards microminiature, synthesis and intelligence. Meanwhile, the structure and the processing technology are very simple, the cost is extremely low, the reliability is high, and the vibration and impact resistance is excellent.
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. An omnidirectional dynamic heat source pendulum type double-shaft micromechanical accelerometer is characterized by comprising a substrate layer, a sensitive layer and a cover plate, wherein,
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 omnidirectional movable heat source swinging 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 acceleration of the X axis and the acceleration of the Y axis;
the omnidirectional dynamic heat source swing heater adopts a wind-fire wheel type sensitive structure, the center of the omnidirectional dynamic heat source swing heater contains a central wheel hub with a circular mass block, and the omnidirectional dynamic heat source swing 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 moving heat source swinging 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 moving heat source pendulum heater are covered with symmetrical electrodes along the Y direction to form a moving resistance type heat source;
the thermistor comprises a pair of thermistors for detecting X-axis acceleration and a pair of thermistors for detecting Y-axis acceleration, and a rectangular middle detection cavity is arranged below the thermistors;
a pair of thermistors for detecting the acceleration of the X axis are symmetrically arranged along the direction of the Y axis and are vertical to the direction of the X axis; a pair of thermistors for detecting the acceleration of the Y axis are symmetrically arranged along the direction of the X axis and are vertical to the direction of the Y axis;
the power-on modes of the omnidirectional moving heat source pendulum heater and the thermistor are constant current;
and the cover plate is etched with a groove and is hermetically connected with the upper surface of the sensitive layer.
2. An omnidirectional dynamic heat source pendulum type dual-axis micromechanical accelerometer according to claim 1, wherein the cover plate and the substrate layer isolate the gas media of the intermediate heating chamber and the intermediate detection chamber from the outside, forming 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 omnidirectional moving heat source pendulum-type dual-axis micromachined accelerometer of claim 1, wherein a depth of the recess of the cover plate is 2/3 of the height of the cover plate.
4. The omnidirectional moving heat source pendulum type biaxial micromechanical accelerometer of claim 1, wherein the height of the omnidirectional moving heat source pendulum heater and thermistor is 100nm to 1000 nm.
5. The omnidirectional moving heat source pendulum-type biaxial micromechanical accelerometer of claim 1, wherein said heater and said thermistor have the same length, which is 1/6-1/5 of the entire width of said sensitive layer.
6. The omnidirectional moving heat source pendulum-type biaxial micromachined accelerometer of claim 1, wherein the heater and thermistor are each comprised of a metal layer consisting of a chromium adhesion layer and a platinum layer.
7. A method for processing the omnidirectional moving heat source pendulum type double-shaft micro-mechanical accelerometer as claimed in any one of claims 1-6 is characterized by comprising 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 structural patterns of an omnidirectional dynamic heat source pendulum heater and a thermistor;
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 all-directional movable heat source pendulum heater and the thermistor structure pattern by adopting an ultrasonic stripping process to form an all-directional movable heat source pendulum 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 omnidirectional moving heat source pendulum heater and the thermistor are suspended and fixed on the sensitive layer through a silicon dioxide film to complete the processing of the sensitive layer of the accelerometer;
step seven: and bonding the cover plate and the sensitive layer by a bonding process to enable the upper surface of the sensitive layer to be positioned in the closed cavity to complete the processing of the sensitive element of the accelerometer, thereby forming the omnidirectional moving heat source pendulum type double-shaft micro mechanical accelerometer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111410353.5A CN113985071A (en) | 2021-11-25 | 2021-11-25 | Omnidirectional dynamic heat source pendulum type double-shaft micro mechanical accelerometer and processing method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111410353.5A CN113985071A (en) | 2021-11-25 | 2021-11-25 | Omnidirectional dynamic heat source pendulum type double-shaft micro mechanical accelerometer and processing method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113985071A true CN113985071A (en) | 2022-01-28 |
Family
ID=79750459
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111410353.5A Pending CN113985071A (en) | 2021-11-25 | 2021-11-25 | Omnidirectional dynamic heat source pendulum type double-shaft micro mechanical accelerometer and processing method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113985071A (en) |
-
2021
- 2021-11-25 CN CN202111410353.5A patent/CN113985071A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111595323A (en) | Single heat source cross flow type micro-mechanical three-axis film gyroscope | |
| CN111623763A (en) | Single heat source micro-mechanical Z-axis film gyroscope | |
| CN214621218U (en) | Full-bridge double-push-pull flow z-axis film gyroscope | |
| CN212082392U (en) | T-shaped micro-mechanical double-shaft film gyroscope with single heat source | |
| CN111595317A (en) | Linear push-pull flow micromechanical uniaxial film gyroscope | |
| CN111595322A (en) | Cross-shaped push-pull flow micro-mechanical three-axis film gyroscope | |
| CN216595183U (en) | Omnidirectional dynamic heat source pendulum type double-shaft micromechanical accelerometer | |
| CN111595315A (en) | T-shaped push-pull flow micromechanical double-shaft film gyroscope | |
| CN214621215U (en) | Double-bridge cross push-pull flow micromechanical z-axis film gyroscope | |
| CN216485109U (en) | Omnibearing dynamic heat source pendulum type three-axis micromechanical accelerometer | |
| CN113985071A (en) | Omnidirectional dynamic heat source pendulum type double-shaft micro mechanical accelerometer and processing method thereof | |
| CN216979122U (en) | Omnibearing moving heat source type Z-axis micromechanical accelerometer | |
| CN216248024U (en) | Dynamic heat source type double-shaft micro-mechanical angular velocity sensor | |
| CN214621217U (en) | Half-bridge push-pull flow z-axis film gyroscope | |
| CN216449608U (en) | Pendulum type omnibearing micromechanical accelerometer with dynamic heat source | |
| CN214621216U (en) | Four-bridge cross-flow type micromechanical z-axis film gyroscope | |
| CN111595319B (en) | Single heat source T-shaped micromechanical triaxial film gyroscope | |
| CN212082390U (en) | T-shaped push-pull flow micromechanical double-shaft film gyroscope | |
| CN114002458A (en) | Omnibearing moving heat source type single-shaft micro mechanical accelerometer and processing method thereof | |
| CN212082388U (en) | Single heat source micro-mechanical Z-axis film gyroscope | |
| CN212082381U (en) | Single heat source convection type micro-mechanical Z-axis film gyroscope | |
| CN212082389U (en) | T-shaped micro-mechanical three-axis film gyroscope with single heat source | |
| CN113985070A (en) | Omnidirectional dynamic heat source pendulum type triaxial micro mechanical accelerometer and processing method thereof | |
| CN216248023U (en) | Dynamic heat source type z-axis micro-mechanical angular velocity sensor | |
| CN114019186A (en) | Omnibearing moving heat source type Z-axis micro mechanical accelerometer and processing method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |