CN102252668B - Silicon micro angular vibration output gyroscope - Google Patents

Abstract

The invention relates to a silicon micro angular vibration output gyroscope composed of an upper layer and a lower layer. The upper layer is a gyroscope mechanical structure arranged on a monocrystalline silicon wafer. The lower layer comprises signal leads arranged on a glass substrate. The upper mechanical structure is composed of two similar-structured substructures, wherein the substructures are symmetrically arranged left and right, and the substructures are connected through a mass block connecting mechanism. The two substructures are respectively connected to crossbeams, which are connected to fixed pedestals through horizontal torsion bars. The fixed pedestals are arranged on fixed pedestal bonding sites on the glass substrate. Therefore, the upper mechanical structure is suspended above the lower glass substrate. The signal leads and the bonding sites are arranged on the lower glass substrate. According to the invention, with the horizontal torsion bar and the crossbeams, the gyroscope rotates around the z axis. Therefore, sensitive motion of the gyroscope is realized; motion decoupling of a driving direction and a detection direction is realized; the number of interference modes is reduced; requirement to processing precision is reduced; and sensitivity of the gyroscope is improved.

Description

The micro-angle vibration output gyro of silicon

Technical field

The invention belongs to microelectromechanical systems and micro-inertia measuring technology, particularly the micro-angle vibration output gyro of a kind of silicon.

Background technology

Micromechanical Inertial Instruments comprises micro-mechanical gyroscope (MMG) and micro-mechanical accelerometer (MMA).Utilize microelectronic processing technology to allow micro mechanical structure and required electronic circuit are completely integrated on a silicon chip, thereby reach the high unity of performance, price, volume, weight, reliability aspects.Thereby this class instrument has a series of advantage (as little as volume, lightweight, low price, reliability high, can produce in enormous quantities etc.), all is being with a wide range of applications aspect the army and the people two.Aspect civilian, be mainly used in auto industry, industrial monitoring and consumer product and Robotics, as air bag, anti-lock braking system, yaw rate sensor, tumble rate sensor, image stability and toy etc.; In military domain, be mainly used in the independent navigation guidance system of agile bomb, intelligent projectile, tactical missile, new concept weapon and miniplane etc.

1993, a kind of micromechanical gyro of novelty-tuning-fork type line oscillation gyro was passed through in the topped silicon layer fabrication techniques of glass surface in U.S. De Leipo laboratory.This gyroscope is comprised of double quality blocks, support beam and crossbeam, the mode that gyroscope adopts line vibratory drive and angular oscillation to detect, can responsive gyroscope plane in axial angular speed.Due to this gyrostatic actuation movement and responsive motion coupling fully, limited the raising of its sensitivity.

2007, the people such as Qiu Anping, Su Yan has developed double quality oscillatory type silicon micro-gyroscopes (application number: 200710133223.5), under the effect of driving force, two quality are being done the line vibration that is parallel to substrate, when the angular speed input is arranged, double quality blocks is done the vibration of the line perpendicular to driving direction that is parallel to substrate, by detecting the variation of sensitization capacitance, test input angular speed.This gyroscope has adopted eight driving support beams and eight responsive support beams to realize separating of driven-mode and responsive mode.Because the relative error of microelectronic technique is larger, mismachining tolerance has a great impact the gyroscope performance.

2009, the people such as Qiu Anping, Su Yan developed again oscillation type silicon micro-gyroscope (application number: 200920037290.1).Adopt torsion bar and crossbeam, gyroscope rotated around Z axis, realize gyrostatic responsive motion, realized driving direction and detection side to mobile decoupling.Torsion bar has replaced responsive support beam, has reduced the support beam number, has reduced the impact of mismachining tolerance on the gyroscope performance.But, in bulk silicon technological, the processing of vertical torsion bar is had to sizable difficulty.

Summary of the invention

The object of the present invention is to provide a kind of mobile decoupling that can realize driven-mode and sensed-mode, affected by mismachining tolerance less, there is the micro-angle vibration output gyro of silicon of high sensitivity, high stability.

The technical solution that realizes the object of the invention is: a kind of pair of micro-angle vibration output gyro of quality silicon, by the physical construction on upper strata and the glass substrate of lower floor, formed, upper strata physical construction is comprised of two identical minor structures, these two minor structures are symmetrically arranged, and interconnect by mass bindiny mechanism.Two minor structures are connected with crossbeam respectively simultaneously, and this crossbeam is connected with fixed pedestal by horizontal torsion bar, and fixed pedestal is arranged on the fixed pedestal bonding point on glass substrate, makes on the unsettled part of the glass substrate in lower floor of physical construction part on upper strata.

The present invention compared with prior art, its remarkable advantage is: (1) and double quality oscillatory type silicon micro-gyroscopes (application number: 200710133223.5) compare, torsion bar has replaced responsive support beam, make gyrostatic responsive motion become angular motion by the line motion, reduced the number of interference modal, reduce the impact of machining precision, improved gyrostatic sensitivity and stability; (2) with oscillation type silicon micro-gyroscope, (application number: 200920037290.1) compare, horizontal torsion bar has replaced vertical torsion bar, realizes responsive motion, has reduced the difficulty of process; (3) with double quality oscillatory type silicon micro-gyroscopes (application number: 200710133223.5) with oscillation type silicon micro-gyroscope (application number: 200920037290.1) compare, two minor structures interconnect by mass bindiny mechanism, increased between operation mode and the difference on the frequency between interference modal, reduced the impact of interference modal on the gyroscope performance; (4) with double quality oscillatory type silicon micro-gyroscopes (application number: 200710133223.5) compare, two minor structures are symmetrically arranged, increased output signal, twice for the single mass output signal, the twice that the angular oscillation output signal is the line vibration output signal simultaneously, so greatly improved gyrostatic sensitivity; (5) adopt torsion bar and crossbeam, gyroscope rotated around the z axle, realize gyrostatic responsive motion, realized driving direction and detection side to mobile decoupling, thereby reduce error signal; The actuation movement of (6) two minor structures and detection motion are move toward one another, form the broach differential capacitor and detect, and have realized responsive output decoupling, have suppressed undesired signal.

Below in conjunction with accompanying drawing, the present invention is described in further detail.

The accompanying drawing explanation

Fig. 1 is the structural representation of the micro-angle vibration output gyro of silicon of the present invention.

Fig. 2 is the signal lead schematic diagram on the glass substrate of the micro-angle vibration output gyro of silicon of the present invention lower floor.

Embodiment

In conjunction with Fig. 1, the micro-angle vibration output gyro of silicon of the present invention, for measuring the angular speed of Z-direction.This gyroscope consists of the physical construction on upper strata and the glass substrate of lower floor.Gyroscope upper strata physical construction is comprised of a pair of identical minor structure 100,200, and these two minor structures 100,200 are symmetrically arranged, and interconnect by mass bindiny mechanism 6, and two minor structures 100,200 all are connected with crossbeam 3a, 3b simultaneously.First crossbeam 3a is connected with the first fixed pedestal 1a by first group of horizontal torsion bar 2a, 2b, 2c, 2d.Second cross beam 3b is connected with the second fixed pedestal 1b by second group of horizontal torsion bar 2e, 2f, 2g, 2h.Mass bindiny mechanism 6 consists of two connecting link 6a, 6b and a connection box 6c, and the end of two connecting link 6a, 6b is connected with connection box 6c respectively, and the other end connects two minor structures 100,200.The the 5th, the 6th torsion bar 2e, 2f in first, second torsion bar 2a, 2b in first group of horizontal torsion bar and second group of horizontal torsion bar arrange along X-direction, and the 7th, the 8th torsion bar 2g, 2h in the 3rd, the 4th torsion bar 2c, the 2d in first group of horizontal torsion bar and second group of horizontal torsion bar arrange along Y direction.The first minor structure 100 is comprised of the first mass 101, driving support beam 105a, 105b, 105c, 105d, driving electric capacity, driving Detection capacitance and Detection capacitance.The second minor structure 200 is comprised of the second mass 201, driving support beam 205a, 205b, 205c, 205d, driving electric capacity, driving Detection capacitance and Detection capacitance.The first mass 101 is by driving support beam 105a, 105b, 105c, 105d to be connected with crossbeam 3a, 3b, wherein first, second drives support beam 105a, 105b to be connected with first crossbeam 3a, and the 3rd, 4 wheel driven moves support beam 105c, 105d and be connected with second cross beam 3b.The second mass 201 is by driving support beam 205a, 205b, 205c, 205d to be connected with crossbeam 3a, 3b, wherein the 5th, the 6th drive support beam 205a, 205b to be connected with first crossbeam 3a, the 7th, the 8th drives support beam 205c, 205d to be connected with second cross beam 3b.The first mass Shang Xia 101 symmetrical movable broach arrange to form with at least four fixed drive broach 103a, 103b, 103c, 103d interdigitations and drive electric capacity, movable broach is arranged to form with at least two fixed drive detection comb 104a, 104b interdigitation and is driven Detection capacitance, and the responsive broach of the activity that left-right symmetric distributes and three fixing responsive broach 102a, 102b, 102c interdigitations are arranged and formed sensitization capacitance; The second mass Shang Xia 201 symmetrical movable broach arrange to form with at least four fixed drive broach 203a, 203b, 203c, 203d interdigitations and drive electric capacity, movable broach is arranged to form with at least two fixed drive detection comb 204a, 204b interdigitation and is driven Detection capacitance, and the responsive broach of the activity that left-right symmetric distributes and three fixing responsive broach 202a, 202b, 202c interdigitations are arranged and formed sensitization capacitance.Apply the alternating voltage with direct current biasing on fixed drive broach 103a, 103b, 103c, 103d, 203a, 203b, 203c, 203d, realize that gyrostatic monolateral static drives.Whole gyrostatic superstructure is connected with the first fixed pedestal 1a by first group of horizontal torsion bar 2a, 2b, 2c, 2d, by second group of horizontal torsion bar 2e, 2f, 2g, 2h, with the second fixed pedestal 1b, is connected, and makes its unsettled being arranged on glass substrate.The first fixed pedestal 1a is connected with the first retainingf key chalaza 4a, the second fixed pedestal 1b is connected with the second retainingf key chalaza 4b, fixed drive broach 103a, 103b, 103c, 103d, 203a, 203b, 203c, 203d, fixed drive feedback broach 104a, 104b, 204a, 204b, fixing responsive broach 102a, 102b, 102c, 202a, 202b, 202c respectively with the corresponding keys chalaza 112a of lower floor's glass substrate, 112b, 112c, 112d, 212a, 212b, 212c, 212d, 113a, 113b, 213a, 213b, 111a, 111b, 111c, 211a, 211b, 211c is connected.

Glass substrate 5 as shown in Figure 2, comprises signal lead and metal silicon/glass bonding point.Signal lead comprises ground wire, drives input lead 109a, 109b, 209a, 209b, drive feedback input lead 110,210, responsive output signal lead-in wire 108,208; Metal silicon/glass bonding point comprises fixed pedestal bonding point 4a, 4b, fixed drive broach bonding point 112a, 112b, 112c, 112d and 212a, 212b, 212c, 212d, fixed drive feedback broach bonding point 113a, 113b and 213a, 213b, fixing responsive broach bonding point 111a, 111b, 111c and 211a, 211b, 211c.

The micro-angle vibration output gyro of silicon of the present invention, adopt monolateral static to drive, the working method of capacitance detecting.Apply the alternating voltage containing DC offset voltage on the fixed drive broach 103a of minor structure 100,103b, 103c, 103d, produce the electrostatic force of alternation, the static driving force is:

$F_d=2\mathrm{n\ϵ}\frac{h}{d}{U}_a{U}_d\sin {\mathrm{\ω}}_{d}t---\left(1\right)$

In formula, the movable comb number of teeth that n is resonator, ε is specific inductive capacity, the thickness that h is structure, d is comb tooth spacing, U _dfor the DC offset voltage of driving voltage, U _afor alternating voltage, ω _dangular frequency for alternating voltage.

In like manner, on fixed fingers 203a, the 203b of minor structure 200,203c, 203d, apply the alternating voltage containing direct current biasing, produce the electrostatic force of alternation, this electrostatic force differs 180 degree with the static driving force acted on minor structure 100.

So the whole bascule of minor structure 100 and 200 is done simple harmonic quantity line vibration in opposite directions along driving shaft under the effect of static driving force.When the natural frequency of the frequency that drives alternating voltage and gyroscope driven-mode is consistent, the line vibration displacement is:

$x=\frac{F_{d0}{Q}_x}{k_x}\cos {\mathrm{\ω}}_{d}t---\left(2\right)$

In formula, F _d0for static driving force amplitude, k _xfor the elastic stiffness of directions X, Q _xquality factor for driven-mode.The line vibration velocity is:

$V=\frac{\mathrm{dx}}{\mathrm{dt}}=\frac{F_{d0}{Q}_x}{k_x}{\mathrm{\ω}}_d\sin {\mathrm{\ω}}_{d}t---\left(3\right)$

When gyroscope has the extraneous input angle speed ω around the z axle _zthe time, according to the right-hand rule, detecting quality and be subject to detecting axial Corioli's acceleration effect, its size is:

In formula,

for dextrorotation angle between input angle speed and line vibration velocity.

If the detection quality is m _s, act on and detect Ge Shi inertial force qualitatively and be:

The direction of Ge Shi inertial force and Corioli's acceleration opposite direction, therefore, act on the opposite direction of Ge Shi inertial force on mass 101,201, form moment loading on gyroscope arrangement, make minor structure 100,200 and crossbeam 3a, 3b make angular oscillation around sensitive axes centered by gyrostatic geometric center.Like this, make the gap between movable responsive broach and fixing responsive broach change by certain simple harmonic oscillation rule, the capacitance difference value signal, after electronic circuit is processed, can obtain output voltage signal.Output voltage signal is minor structure 100,200 output voltage signal sums, and the size of output voltage signal is proportional to the size of input angle speed.The phase relation that compares output voltage signal and pumping signal by phase detector, can distinguish the direction of input angle speed.

Claims (4)

1. the micro-angle vibration output gyro of silicon, by the physical construction on upper strata and the glass substrate of lower floor, formed, it is characterized in that: gyrostatic physical construction is symmetrically arranged by two identical minor structure the first minor structures [100] and the second minor structure [200], the first minor structure [100] and the second minor structure [200] interconnect by mass bindiny mechanism [6], mass bindiny mechanism [6] is by two connecting link [6a, 6b] and a connection box [6c] formation, two connecting link [6a, 6b] an end with connection box [6c], be connected respectively, the other end connects the first minor structure [100] and the second minor structure [200], whole physical construction is connected with the first fixed pedestal [1a] by first group of horizontal torsion bar [2a, 2b, 2c, 2d], be connected with the second fixed pedestal [1b] by second group of horizontal torsion bar [2e, 2f, 2g, 2h], make the physical construction on upper strata unsettled on the glass substrate of lower floor, two groups of horizontal torsion bars [2a, 2b, 2c, 2d, 2e, 2f, 2g, 2h] are all in the XY plane,

The the 5th, the 6th torsion bar [2e, 2f] in first, second torsion bar [2a, 2b] in described first group of torsion bar and second group of torsion bar is arranged along X-direction; The the 7th, the 8th torsion bar [2g, 2h] in the 3rd, the 4th torsion bar [2c, 2d] in first group of torsion bar and second group of torsion bar is arranged along Y direction;

Described the first minor structure [100] is comprised of the first mass [101], the driving electric capacity that drives support beam [105a, 105b, 105c, 105d] and the first mass [101] surrounding, driving Detection capacitance and sensitization capacitance, the first mass [101] is connected with four driving support beams [105a, 105b, 105c, 105d], wherein first, second drives support beam [105a, 105b] to be connected with first crossbeam [3a], and the 3rd, 4 wheel driven moves support beam [105c, 105d] and be connected with second cross beam [3b]; The second minor structure [200] is comprised of the second mass [201], the driving electric capacity that drives support beam [205a, 205b, 205c, 205d] and the second mass [201] surrounding, driving Detection capacitance and sensitization capacitance, the second mass [201] is connected with four driving support beams [205a, 205b, 205c, 205d], wherein the 5th, the 6th drive support beam [205a, 205b] to be connected with first crossbeam [3a], the 7th, the 8th drives support beam [205c, 205d] to be connected with second cross beam [3b].

2. the micro-angle vibration output gyro of silicon according to claim 1 is characterized in that: first crossbeam [3a] is connected with the first fixed pedestal [1a] by first group of horizontal torsion bar [2a, 2b, 2c, 2d]; Second cross beam [3b] is connected with the second fixed pedestal [1b] by second group of horizontal torsion bar [2e, 2f, 2g, 2h].

3. the micro-angle vibration output gyro of silicon according to claim 1, it is characterized in that: the movable broach that the first mass [101] is upper and lower symmetrical and fixed drive broach [103a, 103b, 103c, 103d] interdigitation are arranged to form and are driven electric capacity, movable broach and fixed drive detection comb [104a, 104b] interdigitation are arranged to form and are driven Detection capacitance, and the responsive broach of the activity that left-right symmetric distributes is arranged and formed sensitization capacitance with fixing responsive broach [102a, 102b, 102c] interdigitation; The movable broach that the second mass [201] is upper and lower symmetrical and fixed drive broach [203a, 203b, 203c, 203d] interdigitation are arranged to form and are driven electric capacity, movable broach and fixed drive detection comb [204a, 204b] interdigitation are arranged to form and are driven Detection capacitance, and the responsive broach of the activity that left-right symmetric distributes is arranged and formed sensitization capacitance with fixing responsive broach [202a, 202b, 202c] interdigitation.

4. the micro-angle vibration output gyro of silicon according to claim 1, it is characterized in that: the first fixed pedestal [1a] is connected with the first retainingf key chalaza [4a], the second fixed pedestal [1b] is connected with the second retainingf key chalaza [4b], fixed drive broach [103a, 103b, 103c, 103d, 203a, 203b, 203c, 203d], fixed drive feedback broach [104a, 104b, 204a, 204b], fixing responsive broach [102a, 102b, 102c, 202a, 202b, 202c] respectively with the corresponding keys chalaza [112a of lower floor's glass substrate, 112b, 112c, 112d, 212a, 212b, 212c, 212d, 113a, 113b, 213a, 213b, 111a, 111b, 111c, 211a, 211b, 211c] be connected.

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