Silicon resonance pressure sensor

Abstract

The utility model provides a silicon resonance pressure sensor which comprises a pressure sensing layer, a device layer and a substrate layer. The pressure sensing layer is arranged on one side of the device layer; a pressure film is arranged on the pressure sensing layer; the device layer is provided with a first resonator and a second resonator, and the first resonator and the second resonator are eccentrically arranged on two opposite sides of the device layer; the first resonator and the second resonator are respectively connected with a stress transfer block; the stress transfer block is connected with the pressure film; each of the first resonator and the second resonator comprises two groups of symmetrical resonance units, each group of resonance units comprises a main beam, a connecting beam, a first auxiliary beam and a second auxiliary beam, and the first auxiliary beam and the second auxiliary beam are connected with the main beam through the connecting beam. The silicon resonance pressure sensor has the technical effects that the influence of temperature on the resonance frequency of the silicon resonance pressure sensor can be reduced, and the stability, the precision, the service life and the like of the product are greatly improved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to pressure sensor technical field, concretely relates to a silicon resonance pressure sensor. BACKGROUND

[0002] Pressure sensor is generally divided into piezoresistive, capacitive, resonant type three, at present silicon resonant pressure sensor is widely used in aviation, aerospace and other important fields due to its high precision (the silicon resonant pressure sensor general precision is within 0.02% FS, is superior to piezoresistive pressure sensor more than one order of magnitude), excellent stability and good anti-interference (because it is mechanical vibration signal and vibration frequency can be adjusted) and so on Excellent performance.

[0003] In addition to the precision consideration, temperature drift is also a very important parameter of pressure sensor, but the current silicon resonant pressure resonance unit is usually symmetrical structure, and its final performance is greatly affected by temperature, which greatly shortens its service life. UTILITY MODEL CONTENTS

[0004] The utility model aims at at least one of the technical problems existing in the prior art, and provides a new technical scheme of silicon resonant pressure sensor.

[0005] According to the first aspect of the utility model, a silicon resonant pressure sensor is provided, which comprises a pressure sensing layer, a device layer and a substrate layer;

[0006] The pressure sensing layer is arranged on one side of the device layer;The pressure sensing layer is provided with a pressure film;

[0007] The device layer is provided with a first resonator and a second resonator, and the first resonator and the second resonator are eccentrically arranged on opposite sides of the device layer;The first resonator and the second resonator are respectively connected with a stress transmission block;Wherein, the stress transmission block is connected with the pressure film, the pressure film is used for sensing external pressure, and the external pressure is transmitted to the first resonator and the second resonator through the stress transmission block;

[0008] The first resonator and the second resonator both comprise two symmetrical groups of resonance units, each group of resonance units comprises a main beam, a connecting beam, a first auxiliary beam and a second auxiliary beam, the first auxiliary beam and the second auxiliary beam are respectively located on opposite sides of the main beam and are parallel to the main beam, and the first auxiliary beam and the second auxiliary beam are connected with the main beam through the connecting beam;Wherein, the main beam, the connecting beam, the first auxiliary beam form an I-shaped structure, and the main beam, the connecting beam, the second auxiliary beam form an I-shaped structure;

[0009] The substrate layer is arranged on the other side of the device layer, and a groove corresponding to the resonant unit is arranged on the side of the substrate layer facing the device layer, which provides a deformation space for the vibration of the resonant unit.

[0010] Optionally, a plurality of square release holes are arranged on the main beam, the first auxiliary beam and the second auxiliary beam.

[0011] Optionally, a plurality of triangular release holes are arranged on the connecting beam.

[0012] Optionally, a first movable comb tooth is arranged on the side of the first auxiliary beam away from the main beam, and the device layer is provided with a first fixed comb tooth corresponding to the first movable comb tooth; the first fixed comb tooth and the first movable comb tooth are matched with each other and constitute a first comb tooth pair.

[0013] A second movable comb tooth is arranged on the side of the second auxiliary beam away from the main beam, and the device layer is provided with a second fixed comb tooth corresponding to the second movable comb tooth; the second fixed comb tooth and the second movable comb tooth are matched with each other and constitute a second comb tooth pair.

[0014] A periodic driving signal is loaded to the first comb tooth pair, and the first auxiliary beam generates periodic vibration and drives the main beam and the second auxiliary beam to generate periodic vibration.

[0015] When external pressure is transmitted to the first resonator and the second resonator through the stress transmission block, the second comb tooth pair is used to detect the frequency change of the second auxiliary beam to detect the external pressure.

[0016] Optionally, one end of the main beam is connected to the stress transmission block, and the other end is grounded.

[0017] Optionally, the number of grooves is two; each groove corresponds to two resonant units located on the same side.

[0018] Optionally, a grounding pad, a capacitance detection pad and an electrostatic driving pad are arranged on the side of the substrate layer away from the device layer.

[0019] The grounding pad is connected to the grounding area of the device layer; the electrostatic driving pad is connected to the first fixed comb tooth; and the capacitance detection pad is connected to the second fixed comb tooth.

[0020] Optionally, the number of the grounding pad, the capacitance detection pad and the electrostatic driving pad is two.

[0021] Optionally, a plurality of connecting beams are connected between the main beam and the first auxiliary beam, and the plurality of connecting beams are parallel to each other.

[0022] A plurality of connecting beams are connected between the main beam and the second auxiliary beam, and the connecting beams are parallel to each other.

[0023] Optionally, the pressure membrane is square in shape.

[0024] One technical effect of the utility model lies in:

[0025] In the embodiment of the application, the resonant structure of the silicon resonant pressure sensor is differentially arranged when mechanically vibrating, so that when the pressure membrane transmits external pressure to the two stress transmission blocks, a differential structure of the vibration of the first resonator and the second resonator is formed, thereby offsetting the influence of temperature on the resonant frequency, and greatly improving the service life of the silicon resonant pressure sensor.

[0026] Further, the main beam, the connecting beam and the first auxiliary beam form a I-shaped structure, the main beam, the connecting beam and the second auxiliary beam form a I-shaped structure, the silicon resonant pressure sensor has a plurality of I-shaped structures, which significantly improves the stability of the resonant beam (i.e. the main beam, the first auxiliary beam and the second auxiliary beam) in the vibrating state, and is conducive to the stable output of the performance of the silicon resonant pressure sensor. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 FIG. 1 is a structural schematic diagram of a silicon resonant pressure sensor according to an embodiment of the utility model;

[0028] Figure 2 FIG. 2 is a structural schematic diagram of a device layer of a silicon resonant pressure sensor according to an embodiment of the utility model;

[0029] Figure 3 FIG. 3 is a structural schematic diagram of a first resonator or a second resonator of a silicon resonant pressure sensor according to an embodiment of the utility model;

[0030] Figure 4 FIG. 4 is a structural schematic diagram of a resonant unit of a silicon resonant pressure sensor according to an embodiment of the utility model;

[0031] Figure 5 FIG. 5 is a structural schematic diagram of a pressure membrane of a silicon resonant pressure sensor according to an embodiment of the utility model;

[0032] Figure 6 FIG. 6 is a structural schematic diagram of a groove of a substrate layer of a silicon resonant pressure sensor according to an embodiment of the utility model;

[0033] Figure 7 FIG. 7 is a mechanical simulation diagram of a first perspective view of a silicon resonant pressure sensor according to an embodiment of the utility model;

[0034] Figure 8The utility model discloses a first visual angle's mechanical simulation diagram of a silicon resonance pressure sensor of an embodiment of the utility model.

[0035] Figure 9 The utility model discloses a first visual angle's mechanical simulation diagram of a silicon resonance pressure sensor of an embodiment of the utility model.

[0036] In the figure: 1, device layer;101, ground area;102, static area;103, detection area;2, substrate layer;21, recess;31, first resonator;32, second resonator;4, resonance unit;5, stress transmission block;61, first movable comb tooth;62, first fixed comb tooth;63, second movable comb tooth;64, second fixed comb tooth;71, main beam;72, connecting beam;73, first auxiliary beam;74, second auxiliary beam;81, square release hole;82, triangular release hole;91, ground pad;92, capacitance detection pad;93, static drive pad;10, pressure sensing layer;11, pressure film. DETAILED DESCRIPTION

[0037] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. Note that the relative arrangement, numerical expressions, and numerical values of components and steps set forth in these embodiments are not limiting to the scope of the present application unless specifically stated otherwise.

[0038] The embodiments of the present application will be described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar notations represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by reference to the accompanying drawings are exemplary only, for the purpose of explanation, and are not to be understood as limiting the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work are within the scope of protection of the present application.

[0039] The terms "first", "second" in the specification and claims of the present application can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / ", generally means that the front and rear associated objects are in an "or" relationship.

[0040] In the description of the present application, it needs to be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like are based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0041] In the description of the present application, it needs to be understood that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above-mentioned terms in the present application can be understood according to the specific circumstances.

[0042] According to the first aspect of the present application, referring to Figures 1 to 6 , a silicon resonant pressure sensor is provided, comprising a pressure sensing layer 10, a device layer 1 and a substrate layer 2;

[0043] The pressure sensing layer 10 is arranged on one side of the device layer 1; the pressure sensing layer 10 is provided with a pressure film 10;

[0044] The device layer 1 is provided with a first resonator 31 and a second resonator 32, the first resonator 31 and the second resonator 32 are eccentrically arranged on opposite sides of the device layer 1; the first resonator 31 and the second resonator 32 are respectively connected with a stress transfer block 5 (two stress transfer blocks 5 are also eccentrically arranged relative to the device layer); wherein the stress transfer block 5 is connected with the pressure film 10, the pressure film 10 is used for sensing external pressure, and the external pressure is transmitted to the first resonator 31 and the second resonator 32 through the stress transfer block 5;

[0045] The first resonator 31 and the second resonator 32 each include two symmetrical groups of resonant units 4, each group of the resonant units 4 including a main beam 71, a connecting beam 72, a first auxiliary beam 73 and a second auxiliary beam 74, the first auxiliary beam 73 and the second auxiliary beam 74 being respectively located on opposite sides of the main beam 71 and being parallel to the main beam 71, and the first auxiliary beam 73 and the second auxiliary beam 74 being connected to the main beam 71 through the connecting beam 72; wherein the main beam 71, the connecting beam 72 and the first auxiliary beam 73 form a H-shaped structure, and the main beam 71, the connecting beam 72 and the second auxiliary beam 74 form a H-shaped structure.

[0046] The substrate layer 2 is arranged on the other side of the device layer 1, and a side of the substrate layer 2 facing the device layer 1 is provided with grooves 21 corresponding to the resonant units 4, the grooves 21 being used to provide deformation space for vibration of the resonant units 4.

[0047] In the embodiment, the resonant structure of the silicon resonant pressure sensor forms a differential structure for vibration of the first resonator 31 and the second resonator 32 when the resonant structure is mechanically vibrated due to the asymmetric arrangement of the two stress transmission blocks 5, so that the influence of temperature on the resonant frequency is offset when the pressure membrane 10 transmits external pressure to the two stress transmission blocks 5, and the service life of the silicon resonant pressure sensor is greatly improved.

[0048] Further, the main beam 71, the connecting beam 72 and the first auxiliary beam 73 form a H-shaped structure, and the main beam 71, the connecting beam 72 and the second auxiliary beam 74 form a H-shaped structure, the silicon resonant pressure sensor has a plurality of H-shaped structures, and the stability of the resonant beam (i.e. the main beam 71, the first auxiliary beam 73 and the second auxiliary beam 74) in the vibration state is significantly improved, which is conducive to stable output of the performance of the silicon resonant pressure sensor.

[0049] Optionally, a plurality of square release holes 81 are arranged on the main beam 71, the first auxiliary beam 73 and the second auxiliary beam 74. The plurality of square release holes 81 can better reduce the mass of the main beam 71, the first auxiliary beam 73 and the second auxiliary beam 74, so as to achieve the purpose of regulating the reference frequency of the resonant unit 4.

[0050] Optionally, a plurality of triangular release holes 82 are arranged on the connecting beam 72. The plurality of triangular release holes 82 can better reduce the mass of the connecting beam 72, so as to achieve the purpose of regulating the reference frequency of the resonant unit 4.

[0051] Optionally, a first movable comb tooth 61 is arranged on a side of the first auxiliary beam 73 away from the main beam 71, and the device layer 1 is provided with a first fixed comb tooth 62 corresponding to the first movable comb tooth 61; the first fixed comb tooth 62 and the first movable comb tooth 61 are matched with each other and form a first comb tooth pair.

[0052] The second sub-beam 74 is provided with a second movable comb tooth 63 away from one side of the main beam 71, and the device layer 1 is provided with a second fixed comb tooth 64 corresponding to the second movable comb tooth 63; the second fixed comb tooth 64 and the second movable comb tooth 63 are matched with each other and form a second comb tooth pair;

[0053] A periodic driving signal is loaded to the first comb tooth pair, and the first sub-beam 73 generates periodic vibration and drives the main beam 71 and the second sub-beam 74 to generate periodic vibration;

[0054] When external pressure is transmitted to the first resonator 31 and the second resonator 32 through the stress transmission block 5, the second comb tooth pair is used for detecting the frequency change of the second sub-beam 74 (i.e. the main beam 71 and the first sub-beam 73) to detect the external pressure.

[0055] In the above embodiment, the first sub-beam 73 can realize periodic vibration through the first comb tooth pair, so as to drive the main beam 71 and the second sub-beam 74 to realize stable periodic vibration; the frequency change of the resonant unit 4 can be measured through the second comb tooth pair, so as to realize the measurement of the external pressure.

[0056] The structure design of the resonant unit 4 in the application is reasonable, which helps to improve the accuracy and precision of pressure detection.

[0057] Optionally, one end of the main beam 71 is connected to the stress transmission block 5, and the other end is grounded. This better guarantees the stability of the grounding of the silicon resonant pressure sensor, so as to guarantee the better working performance of the silicon resonant pressure sensor.

[0058] For example, the device layer 1 has a grounding region 101, an electrostatic region 102 and a detection region 103, the other end of the main beam is connected to the grounding region 101, and the connection length of the first main beam of the first resonator to the grounding region 101 is different from the connection length of the first main beam of the second resonator to the grounding region 101, so as to form the eccentric arrangement of the first resonator 31 and the second resonator 32 relative to the device layer 1.

[0059] For example, the first resonator 31 and the second resonator 32 correspond to a detection region 103 respectively, the detection region 103 is located between the two resonant units, and the second fixed comb tooth is arranged in the detection region 103.

[0060] Exemplarily, the device layer 1 is rectangular, and the device layer has a first side wall, a second side wall, a third side wall and a fourth side wall connected in sequence, the first side wall and the third side wall are opposite, the second side wall and the fourth side wall are opposite, two of the connection regions 101 are respectively close to the first side wall and the third side wall, and two of the electrostatic regions 102 are respectively close to the second side wall and the fourth side wall. The two electrostatic regions 102 are respectively located on opposite sides of the first resonator or the second resonator. Each of the electrostatic regions 102 is connected with two of the first fixed combs 62 located on the same side.

[0061] Optionally, the number of the grooves 21 is two; each of the grooves 21 corresponds to two resonant units 4 located on the same side. The design of the groove 21 is reasonable, which can provide a deformation space for the vibration of the resonant unit 4, ensure the effectiveness of the vibration of the resonant unit 4, and thus ensure the measurement accuracy of the silicon resonant pressure sensor.

[0062] Optionally, the substrate layer 2 is provided with a grounding pad 91, a capacitance detection pad 92 and an electrostatic driving pad 93 away from the device layer 1.

[0063] The grounding pad 91 is connected with the connection region 101 of the device layer 1; the electrostatic driving pad 93 is connected with the first fixed comb 62, that is, the electrostatic driving pad 93 is connected with the electrostatic region 102; and the capacitance detection pad 92 is connected with the second fixed comb 64, that is, the capacitance detection pad 92 is connected with the detection region 103.

[0064] In the above embodiment, the grounding pad 91, the capacitance detection pad 92 and the electrostatic driving pad 93 are reasonably designed, which helps to ensure the stability of the electrical connection of each component.

[0065] Optionally, the number of the grounding pad 91, the capacitance detection pad 92 and the electrostatic driving pad 93 is two. This optimizes the connection circuit of the silicon resonant pressure sensor.

[0066] Optionally, a plurality of connecting beams 72 are connected between the main beam 71 and the first auxiliary beam 73, and the plurality of connecting beams 72 are parallel to each other.

[0067] A plurality of connecting beams 72 are connected between the main beam 71 and the second auxiliary beam 74, and the plurality of connecting beams 72 are parallel to each other.

[0068] In the above embodiment, the consistency and stability of the vibration of the resonant unit 4 are ensured, and the measurement accuracy of the silicon resonant pressure sensor is improved.

[0069] Optionally, the pressure membrane 10 is square. This helps to accurately input the external pressure to the silicon resonant pressure sensor through the pressure membrane 10.

[0070] It should be noted that, referring to Figures 7 to 9 According to the mechanical simulation diagram of the silicon resonant pressure sensor, by eccentrically arranging the different positions of the two stress transmission blocks, when the pressure film of the pressure sensing layer is deformed under stress, stress will directly act on the two stress transmission blocks, thereby driving the resonant units of the first resonator and the resonant units of the second resonator to deform in different directions, the silicon resonant pressure sensor forms a differential structure of the resonant units of the first resonator and the resonant units of the second resonator, and the influence of temperature on the device is greatly offset.

[0071] In the embodiment of the present application, the external pressure is deformed by the pressure film 10 to press the stress transmission block 5 to transmit the external pressure to the first resonator 31 and the second resonator 32, the first resonator 31 and the second resonator 32 can form a differential structure, thereby offsetting the influence of temperature on the overall performance drift of the silicon resonant pressure sensor, and avoiding the excessive influence of temperature drift caused by a single resonator.

[0072] Therefore, the present application sets the output of the differential structure frequency of the first resonator and the second resonator, reduces the resonant frequency drift caused by temperature change and stress, and improves the stability, precision, service life and the like of the sensor.

[0073] It can be understood that the above embodiments are only exemplary embodiments adopted for illustrating the principles of the present application, and the present application is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present application, and these modifications and improvements are also regarded as the protection scope of the present application.

Claims

1. A silicon resonant pressure sensor, characterized by, The pressure sensing layer, the device layer and the substrate layer are arranged in sequence. The pressure sensing layer is arranged on one side of the device layer, and a pressure film is arranged on the pressure sensing layer. The device layer is provided with a first resonator and a second resonator, and the first resonator and the second resonator are arranged on opposite sides of the device layer. The first resonator and the second resonator each include two groups of symmetrical resonant units. The substrate layer is arranged on the other side of the device layer, and a groove corresponding to the resonant unit is arranged on the side of the substrate layer facing the device layer.

2. The silicon resonant pressure sensor of claim 1, wherein, The main beam, the first auxiliary beam and the second auxiliary beam are each provided with a plurality of square release holes.

3. The silicon resonant pressure sensor of claim 2, wherein, The connecting beam is provided with a plurality of triangular release holes.

4. The silicon resonant pressure sensor of claim 1, wherein, The first auxiliary beam is provided with a first movable comb tooth on the side away from the main beam, and the device layer is provided with a first fixed comb tooth corresponding to the first movable comb tooth. The second auxiliary beam is provided with a second movable comb tooth on the side away from the main beam, and the device layer is provided with a second fixed comb tooth corresponding to the second movable comb tooth. The first movable comb tooth and the first fixed comb tooth form a first comb tooth pair. The second movable comb tooth and the second fixed comb tooth form a second comb tooth pair.

5. The silicon resonant pressure sensor of claim 4, wherein, The first comb tooth pair is loaded with a periodic driving signal, and the first auxiliary beam generates periodic vibration and drives the main beam and the second auxiliary beam to generate periodic vibration.

6. The silicon resonant pressure sensor of claim 5, wherein, When the external pressure is transmitted to the first resonator and the second resonator through the stress transmission block, the second comb tooth pair is used to detect the frequency change of the second auxiliary beam to detect the external pressure.

7. The silicon resonant pressure sensor of claim 6, wherein, One end of the main beam is connected to the stress transmission block, and the other end is grounded. The number of grooves is two, and each groove corresponds to two resonant units on the same side.

8. The silicon resonant pressure sensor of claim 7, wherein, The substrate layer is provided with a grounding pad, a capacitance detection pad and an electrostatic driving pad on the side away from the device layer.

9. The silicon resonant pressure sensor of claim 7, wherein, The grounding pad is connected to the grounding area of the device layer, the electrostatic driving pad is connected to the first fixed comb tooth, and the capacitance detection pad is connected to the second fixed comb tooth. The number of grounding pads, capacitance detection pads and electrostatic driving pads is two. A plurality of connecting beams are connected between the main beam and the first auxiliary beam, and the plurality of connecting beams are parallel to each other. A plurality of connecting beams are connected between the main beam and the second sub-beam, and the connecting beams are parallel to each other.

10. The silicon resonant pressure sensor of claim 1, wherein, The pressure membrane is square in shape.

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