CN115265850A - Differential rigidity disturbance modal localization high-sensitivity micro-pressure sensor - Google Patents
Differential rigidity disturbance modal localization high-sensitivity micro-pressure sensor Download PDFInfo
- Publication number
- CN115265850A CN115265850A CN202210759226.4A CN202210759226A CN115265850A CN 115265850 A CN115265850 A CN 115265850A CN 202210759226 A CN202210759226 A CN 202210759226A CN 115265850 A CN115265850 A CN 115265850A
- Authority
- CN
- China
- Prior art keywords
- resonant beam
- driving electrode
- resonance
- resonant
- silicon
- 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
- 230000004807 localization Effects 0.000 title abstract description 7
- 230000035945 sensitivity Effects 0.000 claims abstract description 20
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical group [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims abstract description 18
- 230000035882 stress Effects 0.000 claims abstract description 17
- 230000009429 distress Effects 0.000 claims abstract description 9
- 229910052710 silicon Inorganic materials 0.000 claims description 20
- 239000010703 silicon Substances 0.000 claims description 20
- 239000012528 membrane Substances 0.000 claims description 10
- 239000000758 substrate Substances 0.000 claims description 8
- 239000002210 silicon-based material Substances 0.000 claims description 7
- 239000007789 gas Substances 0.000 claims description 6
- 238000004519 manufacturing process Methods 0.000 claims description 6
- OFLYIWITHZJFLS-UHFFFAOYSA-N [Si].[Au] Chemical compound [Si].[Au] OFLYIWITHZJFLS-UHFFFAOYSA-N 0.000 claims description 5
- 230000005496 eutectics Effects 0.000 claims description 5
- 230000005284 excitation Effects 0.000 claims description 4
- 238000009461 vacuum packaging Methods 0.000 claims description 4
- 239000000463 material Substances 0.000 claims description 3
- 229910021421 monocrystalline silicon Inorganic materials 0.000 claims description 3
- 238000012858 packaging process Methods 0.000 claims description 3
- 229910021420 polycrystalline silicon Inorganic materials 0.000 claims description 3
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 2
- 230000006835 compression Effects 0.000 claims description 2
- 238000007906 compression Methods 0.000 claims description 2
- 239000001301 oxygen Substances 0.000 claims description 2
- 229910052760 oxygen Inorganic materials 0.000 claims description 2
- 230000008878 coupling Effects 0.000 abstract description 5
- 238000010168 coupling process Methods 0.000 abstract description 5
- 238000005859 coupling reaction Methods 0.000 abstract description 5
- 230000003247 decreasing effect Effects 0.000 abstract description 4
- 230000000694 effects Effects 0.000 abstract description 4
- 230000009471 action Effects 0.000 abstract description 3
- 230000008859 change Effects 0.000 abstract description 3
- 238000009530 blood pressure measurement Methods 0.000 description 4
- 238000000034 method Methods 0.000 description 4
- 230000003321 amplification Effects 0.000 description 2
- 239000003990 capacitor Substances 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000002955 isolation Methods 0.000 description 2
- 238000003199 nucleic acid amplification method Methods 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 230000005476 size effect Effects 0.000 description 2
- 239000002131 composite material Substances 0.000 description 1
- 230000002596 correlated effect Effects 0.000 description 1
- 230000000875 corresponding effect Effects 0.000 description 1
- 230000001808 coupling effect Effects 0.000 description 1
- 238000013016 damping Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000012212 insulator Substances 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L1/00—Measuring force or stress, in general
- G01L1/16—Measuring force or stress, in general using properties of piezoelectric devices
- G01L1/162—Measuring force or stress, in general using properties of piezoelectric devices using piezoelectric resonators
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measuring Fluid Pressure (AREA)
Abstract
The invention provides a differential stiffness disturbance modal localized high-sensitivity micro-pressure sensor. The sensor is driven by a flat plate type electrostatic actuator, piezoresistance is adopted to detect the vibration amplitude in order to obtain a high signal-to-noise ratio signal, and the vibration amplitude ratio of a resonance beam is used as a final output signal in order to better balance the linear range and the sensitivity. The sensor is of a pure silicon structure, so that the temperature coefficient of the sensor can be reduced to the greatest extent, and the accuracy is improved. The two resonance beams are respectively positioned in a positive stress leading area and a negative stress leading area of the pressure sensitive film to generate differential rigidity disturbance, the two resonance beams realize weak coupling through a thin beam, a modal localization effect is generated under the action of pressure to be measured, and the vibration amplitude ratio can be changed by times or even tens of times. The two weakly coupled resonant beams have the vibration amplitude increased and decreased due to the opposite rigidity change directions, and the sensitivity can be improved by at least one time compared with the condition that the vibration amplitudes change in the same direction. The invention has high reliability due to the simplified structure.
Description
Technical Field
The invention belongs to the field of MEMS (micro-electromechanical systems) micro-sensors, and particularly relates to a differential stiffness disturbance modal localized high-sensitivity micro-pressure sensor.
Background
The micro-pressure sensor has wide application in the fields of vacuum equipment, medical equipment, high-speed aircrafts and the like. At present, the mature micro-pressure sensor mainly adopts the piezoresistive effect and the variable capacitance principle, has the advantages of simple structure, low cost and the like, has the precision of about 1 percent FS to 0.1 percent FS, and can meet the requirements of common civil use and medical treatment. However, in the fields of aerospace, industrial control, etc. with high requirements for precision and reliability, resonant pressure sensors are generally used. The resonant pressure sensor generally adopts a beam-film composite integrated structure, stress is transmitted to a resonator through deformation of a diaphragm so as to change resonant frequency, and pressure measurement is realized by establishing a linear relation between frequency and pressure. Thus, the stiffness of the diaphragm is a critical factor affecting the sensitivity of the sensor. To achieve the micro-pressure measurement, the group Wang Junbo of the chinese academy of sciences in the paper "amicrochinese stressed micro-pressure sensor" in 2021 has improved the sensitivity of the sensor by reducing the thickness of the diaphragm to achieve stress amplification and achieve pressure measurement at the 10kPa range. However, due to the size effect of the resonator itself (structural limitation such as thickness and area), when the thickness of the diaphragm is further reduced, the stiffness of the diaphragm is smaller than that of the resonator, so that further stress amplification cannot be achieved. In addition, the technical route of reducing the thickness of the diaphragm and improving the sensitivity also brings about the problems of overload protection and stress nonlinearity of the sensor in the atmospheric environment, and an additional overload protection device brings about greater challenges to the processing and manufacturing of the sensor.
In recent years, the mode localization effect based on the weak coupling resonator has been widely applied in mass sensors and accelerometers. The invention patent CN201910893549 of China proposes a weak coupling resonance system micro-pressure sensor based on the combination of a quartz resonance beam and a silicon diaphragm, and utilizes the first resonance beam to sense stress and apply rigidity disturbance, while the other resonance beam does not sense stress, and the two resonance beams form a modal localization effect. The problems of sensitivity and overload resistance of the sensor are solved to a certain extent. However, the first resonant beam is only under the action of negative stress, the frequency changes unidirectionally with the pressure, the output amplitude changes unidirectionally, and the effective output range of the circuit is limited to a certain extent. Therefore, a new pressure sensitive structure and a stiffness disturbance mechanism are still required to be adopted to further amplify the sensitivity of the sensor, so that the performance requirement of the micro-pressure sensor with a smaller range is met.
Disclosure of Invention
In order to solve the technical problems, the invention provides a differential stiffness disturbance modal localized high-sensitivity micro-pressure sensor, which adopts the following technical scheme:
a differential stiffness disturbance modal localized high-sensitivity micro-pressure sensor comprises a silicon cover plate and an SOI layer; the silicon cover plate comprises a cavity positioned in the middle; the SOI layer consists of a device layer, an oxygen burying layer and a substrate layer and is used for manufacturing a pressure sensitive unit; the device layer is internally provided with a side resonance beam and a middle resonance beam which have the same structure and size parameters, the side resonance beam and the middle resonance beam are arranged in the middle of a pressure sensitive film positioned on the substrate layer in parallel but not in a collinear manner, the side resonance beam is positioned in a region with a main negative stress, the middle resonance beam is positioned in a region with a main positive stress, when pressure is applied, the two resonance beams respectively generate compression deformation and tensile deformation, and two anchor points respectively fix the side resonance beam and the middle resonance beam and respectively penetrate through the device layer and the buried oxide layer; a thin beam is connected at the overlapping part of the side resonant beam and the middle resonant beam;
the left side and the right side of the side resonant beam are respectively provided with an upper side resonant beam driving electrode and a lower side resonant beam driving electrode, and the left side and the right side of the middle resonant beam are respectively provided with an upper middle resonant beam driving electrode and a lower middle resonant beam driving electrode which are used for exciting the side resonant beam and the middle resonant beam; the side resonant beam upper driving electrode, the side resonant beam lower driving electrode, the middle resonant beam upper driving electrode and the middle resonant beam lower driving electrode are respectively connected with the side resonant beam upper driving electrode pad, the side resonant beam lower driving electrode pad, the middle resonant beam upper driving electrode pad and the middle resonant beam lower driving electrode pad, and the phase difference of alternating current components of excitation voltages of the side resonant beam upper driving electrode and the middle resonant beam lower driving electrode is 180 degrees or 0 degree so that the side resonant beam and the middle resonant beam are in a same-direction or reverse-direction vibration working state; the side resonance beam is provided with a side resonance beam piezoresistive structure and is connected with the side resonance beam piezoresistive structure bonding pad, and the middle resonance beam is provided with a middle resonance beam piezoresistive structure and is connected with the middle resonance beam piezoresistive structure bonding pad and used for detecting the vibration amplitude.
Further, the distance between the thin beam and the two anchor points is equal and variable, the lengths of the side resonant beam, the middle resonant beam and the thin beam are variable, and radial extension lines of the side resonant beam and the middle resonant beam are symmetrical about a horizontal central line of the pressure sensitive film.
Further, the sensor is a silicon material, and the silicon material comprises one or a combination of SOI, monocrystalline silicon and polycrystalline silicon.
Further, the film thickness of the pressure sensitive film is more than 2 times of the height of the side resonant beam and the middle resonant beam.
Further, the silicon cover plate and the SOI layer realize vacuum packaging by utilizing gold-silicon eutectic bonding or silicon-silicon bonding, and a getter is deposited on the upper surface of the cavity to absorb residual gas and gas released by materials in the packaging process, so that a vacuum environment is provided for the side resonant beam and the middle resonant beam.
Furthermore, the side resonant beam and the middle resonant beam are double-end clamped single beams, H-shaped beams or double-end tuning fork beams.
Further, the pressure sensitive membrane is square, circular or rectangular.
Has the advantages that:
(1) The two resonance beams are respectively positioned in the positive stress leading area and the negative stress leading area of the pressure sensitive film to form differential rigidity disturbance, the vibration amplitude of the two resonance beams is increased and decreased once under the weak coupling effect, and the sensitivity can be increased by at least one time under the condition that the relative vibration amplitude is increased or decreased simultaneously.
(2) The invention can obtain high sensitivity characteristic under the condition that the thickness of the pressure sensitive film is larger than the height of the resonance beam, fundamentally solves the problems of atmospheric pressure overload and stress nonlinearity, and solves a series of problems caused by the self size effect of the resonator.
(3) The differential structure formed by the two resonant beams reduces the temperature coefficient to a certain extent and increases the anti-interference capability.
(4) The invention adopts single structural beams such as double-end fixed support single beam and the like as the resonance beam and a single thin beam as the coupling structure, and has simple structure and high reliability.
(5) The invention adopts the plate type electrostatic actuator to excite the resonance beam, has simple structure, high reliability, large driving force and electrode arrangement mode, can provide the function of adjusting the initial rigidity and control the same-direction vibration or the reverse vibration through the alternating current phase difference of the excitation voltage.
(6) The invention adopts piezoresistance detection, has simple structure and is easy to obtain a detection signal with high signal-to-noise ratio.
(7) The sensor of the invention is entirely made of pure silicon materials, has simple manufacture and low cost and is completely compatible with the MEMS process.
Drawings
FIG. 1 is a schematic diagram of differential stiffness perturbation modal localization for the present invention;
FIG. 2 is a three-dimensional schematic diagram of a differential stiffness perturbation modal localized high sensitivity micro-pressure sensor of the present invention; wherein, 100-silicon cover plate; 110-a cavity; a 300-SOI layer; 310-a device layer; 320-buried oxide layer; 330-a substrate layer; 340-a pressure sensitive membrane; 400-side resonant beam; 500-middle resonance beam; 600-thin beam;
FIG. 3 is a front view of the SOI layer of the present invention; wherein, 310-device layer; 340-a pressure sensitive membrane; 350-anchor point; 370-silicon conductive lines; 390-an electrical isolation slot; 400-side resonant beam; 411-side resonant beam upper drive electrode; 412-side resonant beam lower drive electrode; 416-drive electrode pads on the resonant beam; 417-side resonant beam lower drive electrode pad; 420-side resonant beam piezoresistive structure; 426-side resonant beam piezoresistive structural bonding pad; 500-middle resonance beam; 511-upper driving electrodes of the middle resonance beam; 512-middle resonance beam lower driving electrode; 516-drive electrode pads on the resonant beam; 517-lower driving electrode pad of middle resonance beam; 520-middle resonant beam piezoresistive structure; 526-middle resonant beam piezoresistive structure bonding pad; 600-thin beam;
FIG. 4 is a bottom view of the differential stiffness perturbation modal localized high sensitivity micro-pressure sensor of the present invention; wherein, 100-silicon cover plate; 310-a device layer; 320-buried oxide layer; 330-a substrate layer; 331-first lead aperture; 332-second lead aperture; 334-third lead hole; 335-fourth wire hole; 333-fifth wire hole; 336-sixth lead aperture; 337-seventh lead aperture; 340-pressure sensitive membrane.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.
The invention provides a differential stiffness disturbance modal localized high-sensitivity micro-pressure sensor which can improve the sensitivity to the maximum extent. The sensor is of a beam-film integrated structure and is composed of an SOI (Silicon on Insulator) core body and a Silicon cover plate, wherein the SOI core body and the Silicon cover plate are in vacuum packaging through gold-Silicon eutectic bonding, so that high quality factors are obtained, and stable vibration of the resonator is facilitated. The resonator adopts two single resonant beams with two ends fixedly supported, the two resonant beams are arranged in parallel and are respectively positioned in a region with main positive stress and a region with main negative stress, certain overlapping is formed in the length direction, and the overlapped parts are connected through thin beams to realize weak coupling. Two resonant beams are driven to work in a same-direction vibration working mode through two parallel plate type electrostatic actuators. As shown in fig. 1, Δ k1 and Δ k2 represent effective stiffness variation amounts of a resonant beam in a negative stress dominant region and a resonant beam in a positive stress dominant region, respectively, under the action of a pressure to be measured, a positive stress dominant region and a negative stress dominant region are generated by a pressure sensitive film, the two resonant beams respectively undergo tensile deformation and compressive deformation, the effective stiffness accordingly generates variation of Δ k1 and Δ k2, Δ k2 is a positive increment, Δ k1 is a negative increment, further, resonance frequencies of the two resonant beams respectively increase and decrease, meanwhile, vibration amplitudes of the two resonant beams are decreased and increased to form differential variation as the vibration amplitudes are negatively correlated with the effective stiffness, the vibration amplitude ratio of the two resonant beams can be changed by several times, and compared with the amplitude homodromous variation sensitivity can be increased by at least one time. Therefore, the sensitivity of the resonant sensor can be multiplied or even multiplied by tens of times on a thicker pressure sensitive film (which is multiplied by the sectional height of the resonator), and the problems of overload resistance and stress nonlinearity are well solved. The piezoresistive structures on the two resonant beams are used for detecting the respective vibration amplitude, compared with the modes of capacitance, piezoelectricity, electromagnetism and the like, the piezoresistive structure is simple to manufacture, and a high signal-to-noise ratio signal is easier to obtain. The structures adopt simplified design and simple process, so the structure has the characteristic of high reliability.
As shown in fig. 2 and 3, the differential stiffness perturbation modal localization high-sensitivity micro-pressure sensor of the present invention is divided into two parts: a silicon lid 100 and an SOI layer 300. The silicon lid 100 includes a square cavity 110 in the middle of the silicon lid 100, which is a vacuum chamber that provides a reference pressure for pressure measurement and provides a high vacuum low damping environment for the resonant beam. The SOI layer 300 is comprised of three layers, a device layer 310, a buried oxide layer 320, and a substrate layer 330. The SOI layer 300 is used for manufacturing a pressure sensitive unit, and includes a side resonant beam 400, a middle resonant beam 500, a thin beam 600, a pressure sensitive membrane 340, two anchor points 350, an electrical isolation groove 390, a side resonant beam upper driving electrode pad 416, a side resonant beam lower driving electrode pad 417, a side resonant beam piezoresistive structure pad 426, a middle resonant beam upper driving electrode pad 516, a middle resonant beam lower driving electrode pad 517, and a middle resonant beam piezoresistive structure pad 526.
The side resonant beam 400 and the middle resonant beam 500 with the same structure and size parameters are positioned in the device layer 310, the side resonant beam 400 and the middle resonant beam 500 are manufactured by the device layer 310, the side resonant beam 400 and the middle resonant beam 500 are arranged in the middle of the pressure sensitive film 340 in parallel but not in a collinear manner, the side resonant beam 400 is positioned in the negative stress leading area, the middle resonant beam 500 is positioned in the positive stress leading area, the two anchor points 350 are used for fixing the two, the two anchor points 350 penetrate through the device layer 310 and the buried oxide layer 320, so that the side resonant beam 400 and the middle resonant beam 500 are respectively fixed on the pressure sensitive film 340, and the thickness of the pressure sensitive film 340 is more than 2 times larger than the height of the side resonant beam 400 and the middle resonant beam 500, so that the problems of atmospheric pressure overload resistance and stress nonlinearity are solved. A thin beam 600 is connected at the overlapping position of the side resonance beam 400 and the middle resonance beam 500, the distance between the side resonance beam 400 and the middle resonance beam 500 is equal and variable, the length of the side resonance beam 400, the middle resonance beam 500 and the thin beam 600 is variable, and the radial extension lines of the side resonance beam 400 and the middle resonance beam 500 are symmetrical about the horizontal center line of the pressure sensitive film 340. The outer border of the cavity 110 on the silicon lid 100 is 35 microns larger than the border of the pressure sensitive film 340 and the projections of the centers of the patterns coincide with each other. The silicon cover plate 100 and the SOI layer 300 are vacuum-packaged by using gold-silicon eutectic bonding, and a getter is deposited on the upper surface of the cavity 110 to absorb residual gas and gas released by materials in the packaging process, so as to provide a vacuum environment for the edge resonant beam 400 and the middle resonant beam 500.
As shown in fig. 3, the side resonant beam 400 and the middle resonant beam 500 have the same physical structure and size, the side resonant beam 400 and the middle resonant beam 500 are respectively provided with a side resonant beam upper driving electrode 411, a side resonant beam lower driving electrode 412, a middle resonant beam upper driving electrode 511 and a middle resonant beam lower driving electrode 512 at the left and right sides of the side resonant beam 400 and the middle resonant beam 500 for exciting the side resonant beam 400 and the middle resonant beam 500, the side resonant beam upper driving electrode pad 416, the side resonant beam lower driving electrode pad 417, the middle resonant beam upper driving electrode pad 516 and the middle resonant beam lower driving electrode pad 517 are connected with the corresponding side resonant beam upper driving electrode pad 416, the side resonant beam lower driving electrode pad 417, the middle resonant beam upper driving electrode pad 516 and the middle resonant beam lower driving electrode pad 517 through a silicon wire 370, the phase difference of the ac component of the excitation voltage between the side resonant beam upper driving electrode 411 and the middle resonant beam lower driving electrode 512 is 180 °, and the side resonant beam 400 and the middle resonant beam 500 are in the same-direction vibration operating state. The side resonator beam 400 has a side resonator beam piezoresistive structure 420 connected to a side resonator beam piezoresistive structure pad 426, and the middle resonator beam 500 has a middle resonator beam piezoresistive structure 520 connected to a middle resonator beam piezoresistive structure pad 526 for detecting vibration amplitude.
As shown in fig. 4, the pressure sensitive membrane 340 is located on the substrate layer 330, and the central projections of the two coincide. The total number of the lead holes is 10, and the section is circular. The first, second, third and fourth lead holes 331, 332, 334 and 335 correspond to the side resonant beam upper driving electrode pad 416, the side resonant beam lower driving electrode pad 417, the middle resonant beam upper driving electrode pad 516 and the middle resonant beam lower driving electrode pad 517, respectively, the fifth and sixth lead holes 333 and 336 correspond to the side resonant beam piezoresistive structure pad 426 and the middle resonant beam piezoresistive structure pad 526, respectively, and the seventh lead hole 337 is used for grounding the device layer 310. Preferably, the structure of the pressure sensitive membrane 340 includes, but is not limited to, a single sensitive membrane with a regular shape such as a square, a circle, a rectangle, etc., and the direction of the resonant beam is not limited when the pressure sensitive membrane 340 is a circle or a regular polygon.
Preferably, the sensor is a silicon material, and the silicon material includes one or a combination of several of SOI, monocrystalline silicon and polycrystalline silicon.
Preferably, the side resonator beam and the middle resonator beam include, but are not limited to, a single-structure resonator beam such as a double-clamped single beam, an H-beam, and a double-clamped tuning fork beam.
Preferably, the plate-type electrostatic actuators of the side and middle resonant beams can be replaced by a lareral comb capacitor, a Transverse comb capacitor, or other similar structures.
Preferably, the side resonant beam and the middle resonant beam are not limited to the same-direction vibration mode, and the two resonant beams can realize reverse vibration through different combinations of the 4 driving electrodes of the two resonant beams.
Preferably, the vacuum packaging method of the SOI layer and the silicon cover plate includes, but is not limited to, gold silicon eutectic bonding, silicon-silicon bonding, and other direct bonding methods.
Preferably, the SOI layer may be replaced with an equivalent structural core formed by silicon-silicon bonding or the like.
It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.
Claims (7)
1. A differential rigidity disturbance mode localized high-sensitivity micro-pressure sensor is characterized in that: comprises a silicon cover plate and an SOI layer; the silicon cover plate comprises a cavity positioned in the middle; the SOI layer consists of a device layer, an oxygen burying layer and a substrate layer and is used for manufacturing a pressure sensitive unit; the device layer is internally provided with a side resonance beam and a middle resonance beam which have the same structure and size parameters, the side resonance beam and the middle resonance beam are arranged in the middle of a pressure sensitive film positioned on the substrate layer in parallel but not in a collinear manner, the side resonance beam is positioned in a region with a main negative stress, the middle resonance beam is positioned in a region with a main positive stress, when pressure is applied, the two resonance beams respectively generate compression deformation and tensile deformation, and two anchor points respectively fix the side resonance beam and the middle resonance beam and respectively penetrate through the device layer and the buried oxide layer; a thin beam is connected at the overlapping part of the side resonant beam and the middle resonant beam;
the left side and the right side of the side resonant beam are respectively provided with a side resonant beam upper driving electrode and a side resonant beam lower driving electrode, and the left side and the right side of the middle resonant beam are respectively provided with a middle resonant beam upper driving electrode and a middle resonant beam lower driving electrode which are used for exciting the side resonant beam and the middle resonant beam; the side resonant beam upper driving electrode, the side resonant beam lower driving electrode, the middle resonant beam upper driving electrode and the middle resonant beam lower driving electrode are respectively connected with a side resonant beam upper driving electrode pad, a side resonant beam lower driving electrode pad, a middle resonant beam upper driving electrode pad and a middle resonant beam lower driving electrode pad, and the phase difference of alternating current components of excitation voltages of the side resonant beam upper driving electrode and the middle resonant beam lower driving electrode is 180 degrees or 0 degree so that the side resonant beam and the middle resonant beam are in a same-direction or reverse-direction vibration working state; the side resonance beam is provided with a side resonance beam piezoresistive structure and is connected with a side resonance beam piezoresistive structure bonding pad, and the middle resonance beam is provided with a middle resonance beam piezoresistive structure and is connected with the middle resonance beam piezoresistive structure bonding pad for detecting the vibration amplitude.
2. The differential stiffness perturbation modal localized high sensitivity micro-pressure sensor of claim 1, wherein: the distance between the thin beam and the two anchor points is equal and variable, the lengths of the side resonant beam, the middle resonant beam and the thin beam are variable, and the radial extension lines of the side resonant beam and the middle resonant beam are symmetrical about the horizontal central line of the pressure sensitive film.
3. The differential stiffness perturbation modal localized high sensitivity micro-pressure sensor of claim 1, wherein: the sensor is made of silicon materials, and the silicon materials comprise one or a combination of SOI, monocrystalline silicon and polycrystalline silicon.
4. The differential stiffness perturbation modal localized high sensitivity micro-pressure sensor of claim 1, wherein: the film thickness of the pressure sensitive film is more than 2 times of the height of the side resonant beam and the middle resonant beam.
5. The differential stiffness perturbation modal localized high sensitivity micro-pressure sensor of claim 1, wherein: the side resonant beam and the middle resonant beam are double-end fixed single beams, H-shaped beams or double-end tuning fork beams.
6. The differential stiffness perturbation modal localized high sensitivity micro-pressure sensor of claim 1, wherein: the pressure sensitive membrane is square, round or rectangular.
7. The differential stiffness perturbation modal localized high sensitivity micro-pressure sensor of claim 1, wherein: the silicon cover plate and the SOI layer realize vacuum packaging by utilizing gold-silicon eutectic bonding or silicon-silicon bonding, and a getter is deposited on the upper surface of the cavity to absorb residual gas and gas released by materials in the packaging process, so that a vacuum environment is provided for the side resonant beam and the middle resonant beam.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210759226.4A CN115265850A (en) | 2022-06-30 | 2022-06-30 | Differential rigidity disturbance modal localization high-sensitivity micro-pressure sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210759226.4A CN115265850A (en) | 2022-06-30 | 2022-06-30 | Differential rigidity disturbance modal localization high-sensitivity micro-pressure sensor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115265850A true CN115265850A (en) | 2022-11-01 |
Family
ID=83763247
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210759226.4A Pending CN115265850A (en) | 2022-06-30 | 2022-06-30 | Differential rigidity disturbance modal localization high-sensitivity micro-pressure sensor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115265850A (en) |
-
2022
- 2022-06-30 CN CN202210759226.4A patent/CN115265850A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP2643702B1 (en) | Resonant biaxial accelerometer structure of the microelectromechanical type | |
| US6484578B2 (en) | Vibrating beam accelerometer | |
| CN109786422B (en) | Piezoelectric excitation tension type silicon micro-resonance pressure sensor chip and preparation method thereof | |
| CN111289156B (en) | Differential silicon micro-resonance type pressure sensor based on electrostatic excitation piezoresistive detection | |
| CN108375371B (en) | Four-degree-of-freedom weak coupling resonant accelerometer based on modal localization effect | |
| US6311556B1 (en) | Micro-accelerometer with capacitive resonator | |
| CN102128953B (en) | Capacitive micro-acceleration sensor with symmetrically inclined folded beam structure | |
| GB2578014A (en) | Acceleration sensor comprising differential graphene resonant beams | |
| CN110501098B (en) | High-sensitivity micro-pressure sensor based on double-pressure membrane and weak coupling resonance system | |
| US6089088A (en) | Vibrating microgyrometer | |
| CN102590555A (en) | Resonance-force balance capacitance type three-axis acceleration transducer and manufacture method | |
| US20140024161A1 (en) | Method of fabricating an inertial sensor | |
| CN101271124B (en) | L-beam piezoresistance type micro-accelerometer and production method thereof | |
| CN103808961A (en) | Cantilever part and resonant acceleration sensor using the same | |
| US7104128B2 (en) | Multiaxial micromachined differential accelerometer | |
| CN107356785B (en) | MEMS torsion type accelerometer with flexible hinge structure | |
| CN109883581B (en) | Cantilever beam type differential resonance pressure sensor chip | |
| CN113092817B (en) | High-precision and wide-range acceleration sensor with switchable detection modes and control method thereof | |
| CN113945732A (en) | Graphene double-shaft differential resonant accelerometer | |
| CN107101629B (en) | Silicon micromechanical graphene beam resonant gyroscope | |
| CN112964905A (en) | Piezoresistive double-shaft acceleration sensor chip and preparation method thereof | |
| Eswaran et al. | Sensitivity analysis on MEMS capacitive differential pressure sensor with bossed diaphragm membrane | |
| CN115265850A (en) | Differential rigidity disturbance modal localization high-sensitivity micro-pressure sensor | |
| CN110672236A (en) | Resonator based on electrostatic driving and differential piezoresistive detection and pressure sensor thereof | |
| Yu et al. | An electrostatic comb excitation resonant pressure sensor for high pressure applications |
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 |