RU30999U1 - Micromechanical accelerometer - Google Patents

Abstract

1. A micromechanical accelerometer containing a housing made in the form of a board made of dielectric material with the stationary electrodes of a comb electrostatic force sensor and a motion sensor sprayed on it, an inertial mass made in the form of a silicon plate located with a gap relative to the housing and connected through elastic jumpers with supporting elements forming an elastic suspension, providing the inertial mass to move along an axis lying in the plane of the inertial mass, electronic circuitry Botko signals, characterized in that the inertial mass, elastic webs, the supporting elements, movable comb electrodes of the electrostatic force sensor and the displacement sensor formed by a single element kremniya.2 anisotropic etching. The device according to claim 1, characterized in that the silicon wafer is made in the form of a rectangle, on the surface of which through holes are evenly distributed, made in the form of a rectangle, the diagonal of which is not less than twice the initial gap between the inertial mass and the board. The device according to claims 1 and 2, characterized in that the elastic suspension contains four elastic jumpers located inside the through slots made in the inertial mass and parallel to its short sides, one end of each of the jumpers is connected to the inertial mass, and the other end through the reference the element is mounted on the housing. The device according to claims 1 and 2, characterized in that the electrodes of the comb electrostatic force sensor and the displacement sensor are placed on opposite sides of the inertial mass in the e direction

Description

MICROMECHANICAL ACCELEROMETER

The invention relates to measuring equipment, in particular, to the field of instrumentation, and may find application in inertial systems of moving objects, in autopilots of aircraft and ship models, in vehicle safety systems.

A feature of micromechanical accelerometers is the predominant manufacture of sensitive elements of these devices from materials based on silicon technology, which determines: small dimensions and weight of the accelerometer, Possibility - the use of group manufacturing technology and, therefore, cheap manufacturing in mass production, high reliability in operation.

The technical solution is known Konovalov S.F., Lapteva T.N., Medvedeva I.I., Novoselov G.M., Poland A.V., Trunov A.A., Konovchenko A.A., Prokofiev V.M. , Lee KS, Luke F. Opyg development of navigation devices based on a silicon single crystal / TM Microsystem technology, 2001.., P. 19-24, in which the accelerometer contains a housing, an inertial mass made in the form of a silicon plate, located with a gap relative to the housing and connected with it through elastic jumpers with supporting elements forming an elastic suspension for moving the inertial mass, a torque sensor, an angle sensor signal processing electronic circuit.

The disadvantage of this solution is the complexity of the design and complex manufacturing technology.

Known technical solution EP 00822415 A1 02/04/98, cl. GO1P 15/08. Integral capacitive acceleration sensor and method of its manufacture // REKKA111, PAOLO; FORONI, MARIO; VIGNA, BENEDETTO; VILLA, FLAVIO, most similar to the proposed invention, in which the micromechanical accelerometer comprises a housing made in the form of a board made of dielectric material with fixed electrodes of a comb electrostatic force sensor and a motion sensor fixed thereto, an inertial mass made in the form of a silicon plate located with a gap relative to the housing and connected through elastic bridges with supporting elements forming an elastic suspension, providing the inertial mass to move along the axis lying in the plane of inertial mass, electronic signal processing circuit.

MPKOO1R 15/08

The disadvantage of this micromechanical accelerometer is the complex technology of its manufacture.

The present invention is the development of a micromechanical accelerometer, which allows to simplify the manufacturing technology.

The technical result was obtained due to the fact that in the micromechanical accelerometer containing a housing made in the form of a board made of dielectric material with fixed electrodes of a comb electrostatic force sensor and a motion sensor fixed on it, the inertial mass made in the form of a silicon plate located with a gap with respect to case and connected with it through elastic jumpers with supporting elements forming an elastic suspension, providing the movement of the inertial mass along the axis lying in loskosti inertial mass, electronic signal processing circuit, the inertial mass, elastic webs, the supporting elements, movable comb electrodes of the electrostatic force sensor and the displacement sensor element made uniform anisotropic silicon etching. The silicon wafer can be made in the form of a rectangle, on the surface of which through holes are evenly distributed, made in the form of a rectangle, the diagonal of which is not less than twice the size of the initial gap between the inertial mass and the board. An elastic suspension may contain four elastic jumpers located inside the through slots made in the inertial mass and located parallel to its short sides, one end of each of their jumpers is connected with the inertial mass, and the other end is fixed to the body through the support element. The electrodes of a comb electrostatic force sensor and a displacement sensor can be placed on opposite sides of the inertial mass in the direction of its axis of symmetry.

When performing inertial mass, elastic jumpers, supporting elements, movable electrodes of a comb electrostatic force sensor and a displacement sensor as a single element, anisotropic etching of silicon simplifies the manufacturing technology of a micromechanical accelerometer.

The list of drawings:

FIG. 1 is a structural diagram of a micromechanical accelerometer;

In FIG. 1 shows a structural diagram of an accelerometer; in FIG. 2 - inertial mass with elastic jumpers, supporting elements and movable electrodes comb electrostatic force sensor and displacement sensor; in FIG. 3 is an electronic signal processing circuit.

The micromechanical accelerometer (Fig. 1) comprises a housing 1 made in the form of a board made of dielectric material. An inertial mass 2 is placed in the housing 1, made in the form of a direct-bonded silicon wafer located with a gap relative to the housing 1 and connected by elastic jumpers 3. The elastic jumpers 3 are rigidly fastened to the housing 1 at one ends through the supporting elements 4, the second ends are connected with inertial mass 2 (Fig. 2). The elastic moment 3 form an elastic suspension, providing the movement of the inertial mass 2 along the axis X-X lying in the plane of the inertial mass 2 and which is the sensitivity axis of the device. In the inertial mass 2, four through slots are made, inside of which there are elastic jumpers 3. The inertial mass 2 is made in the form of a rectangular plate, on the surface of which through holes 5 of a rectangular shape are evenly distributed (Fig. 2). Each side of the inertial mass 2 is made in the form of comb teeth 7, 11, which play the role of movable electrodes of the force sensor 6 and the displacement sensor 9. The stationary electrodes 8, 10 of the force sensor 6 and the displacement sensor 9 are mounted on the housing 1. The electronic signal processing circuit (Fig. 3) contains a master oscillator 12, an amplifier 13, a demodulator 14, a correction amplifier 15. The signal from the master oscillator 12 is supplied both to the electrodes of the displacement sensor 9 and the force sensor 6, and to the demodulator 14. Feedback is provided by supplying a signal from the output ode corrective amplifier 15 to the input of the amplifier 13.

The proposed device operates as follows. Under the action of linear acceleration in the direction of the sensitivity axis X-X, the inertial mass 2 deviates from its initial position. In this case, the capacitance between the movable and stationary electrodes of the displacement sensor 9 changes. The signal taken from the displacement sensor 9 is fed through a capacitor C3 to an amplifier 13, and then through a demodulator 14 to a correction amplifier 15. To ensure the operation of the force sensor 6, a constant bias Uo is introduced. The interaction of the bias voltage UQ with the feedback signal coming from the output of the correction amplifier 15 leads to the appearance of an electrostatic moment, which tends to return the inertial mass 2 to the initial steady state

position. In the steady state, the inertia force acting on the inertial mass 2 is balanced by the electrostatic forces of the force sensor 6. The voltage at the output of the correcting amplifier 15 is the output signal of the accelerometer.

Thus, the claimed micromechanical accelerometer allows to simplify the manufacturing technology.

Claims (4)

1. A micromechanical accelerometer containing a housing made in the form of a board made of dielectric material with the stationary electrodes of a comb electrostatic force sensor and a motion sensor sprayed on it, an inertial mass made in the form of a silicon plate located with a gap relative to the housing and connected through elastic jumpers with supporting elements forming an elastic suspension, providing the inertial mass to move along an axis lying in the plane of the inertial mass, electronic circuitry Botko signals, characterized in that the inertial mass, elastic webs, the supporting elements, movable comb electrodes of the electrostatic force sensor and the displacement sensor element made uniform anisotropic silicon etching. 2. The device according to claim 1, characterized in that the silicon wafer is made in the form of a rectangle, on the surface of which through holes are evenly distributed, made in the form of a rectangle, the diagonal of which is not less than twice the initial gap between the inertial mass and the board. 3. The device according to claims 1 and 2, characterized in that the elastic suspension contains four elastic jumpers located inside the through slots made in the inertial mass and parallel to its short sides, one end of each of the jumpers is connected with the inertial mass, and the other end through the support element is fixed to the housing. 4. The device according to claims 1 and 2, characterized in that the electrodes of the comb electrostatic force sensor and the displacement sensor are placed on opposite sides of the inertial mass in the direction of its symmetry axes.