Gyro element, angular velocity sensor and electronic device

Abstract

The present invention provides a gyro element, comprising: a central island; a detection fork finger, which is connected to the central island; a driving fork finger, which is connected to the central island via a connecting beam; an inner frame, which is a rigid structure, surrounds the detection fork finger, the driving fork finger and the central island, and is connected to the central island via an electrical connecting beam; an outer frame, which is a rigid structure, surrounds the inner frame, and is connected to the inner frame via a flexible connecting component located between the inner frame and the outer frame; and a wiring point, which is configured to electrically connect the outer frame to the outside world. In the case of fixing and supporting the gyro element, the interference of external vibration on the gyro element is reduced, thereby reducing the influence on the sensitivity of the gyro sensor.

Description

Technical Field

[0001] The present invention relates to the technical field of gyroscopes, and in particular to a gyro element, an angular velocity sensor, and an electronic device. Background Art

[0002] Nowadays, gyroscope sensors are widely used, and the demand for IMUs (Inertial Measurement Units) and three-axis gyro sensors is increasing continuously. To meet the requirements of miniaturization and portability, surface-mounted Z-axis gyro elements have emerged. Most of the existing Z-axis gyro elements have a "Sichuan" shape structure, and the central island in the element also participates in vibration. When the element is fixed and connected to the outside world, if the gyro element is rigidly fixed, for a tuning fork, rigid fixation will greatly weaken the vibration of the tuning fork, affect the vibration transmission between the tuning forks, and thus reduce the sensitivity of the gyroscope sensor; if the gyro element is flexibly connected, there will be a stress matching problem, and it cannot fix and support the element well, and the selection of the material of the connecting structure is also a difficult problem. That is to say, in the prior art, how to reduce the influence on the sensitivity of the gyroscope sensor while fixing and supporting the gyro element. Summary of the Invention

[0003] (I) Technical Problems to be Solved The present invention provides a gyro element, an angular velocity sensor, and an electronic device, which are used to solve the problem that in the prior art, it is impossible to simultaneously achieve the fixation and support of the gyro element and maintain the sensitivity of the gyroscope sensor.

[0004] (II) Technical Solutions The present invention provides a gyro element, including: A central island; Detection finger electrodes, the detection finger electrodes are connected to the central island; Drive finger electrodes, the drive finger electrodes are connected to the central island via a connecting beam; An inner frame, the inner frame is a rigid structure, surrounds the detection finger electrodes, the drive finger electrodes and the central island, and is connected to the central island via an electrical connection beam; An outer frame, the outer frame is a rigid structure, surrounds the inner frame, and is connected to the inner frame via a flexible connection member located between the inner frame and the outer frame; and A connection point, the connection point is configured to electrically connect the outer frame to the outside world.

[0005] In an optional embodiment, in the same plane, the central island is located at the center of the gyro element, a pair of the detection fork fingers extend from the central island in the positive and negative directions of the Y-axis respectively, two pairs of the drive fork fingers are arranged in parallel on both sides of the detection fork fingers, each pair of the drive fork fingers extend in the positive and negative directions of the Y-axis respectively, the connecting beam extends from the central island in the X-axis direction, the detection fork fingers are arranged perpendicularly to the connecting beam, the drive fork fingers are arranged perpendicularly to the connecting beam, and the electrical connecting beam is located between the detection fork fingers and the drive fork fingers.

[0006] In an optional embodiment, the inner frame and the outer frame are rotationally symmetric with respect to the center of gravity of the gyro element.

[0007] In an optional embodiment, the width of the driving fingers is greater than the width of the detecting fingers, and the width of the detecting fingers is greater than the width of the electrical connection beam.

[0008] In an optional embodiment, the ends of the detection fingers are formed in a hammer head shape, and the ends of the driving fingers are formed in a hammer head shape.

[0009] In an optional embodiment, the gyro element is an integrally formed quartz crystal structure, and a gold electrode layer is covered on the surface of the gyro element.

[0010] The present invention also provides an angular velocity sensor, comprising: A gyroscopic element as described in any of the preceding paragraphs; a support base disposed below the gyro element and comprising a support edge electrically connected to the wiring point; and A cover portion is located above the gyro element and is combined with the support base to accommodate the gyro element.

[0011] In an optional embodiment, the support base is made of ceramic, and the support edge is electrically connected to the wiring point via a conductive adhesive.

[0012] In an optional embodiment, the conductive adhesive has a thickness of 10-20 μm.

[0013] The present invention also provides an electronic device, comprising the angular velocity sensor as described in any one of the above.

[0014] (III) Beneficial effects The present invention provides a gyro element, an angular velocity sensor and an electronic device. By forming a double-layer vibration reduction structure in the gyro element, the gyro element is fixed and supported, the interference of external vibration on the gyro element is reduced, and the influence on the sensitivity of the gyro sensor is further reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 A plan view of a gyro element according to an embodiment of the present invention; Figure 2 A plan view of a gyro element according to another embodiment of the present invention; Figure 3 A plan view of a gyro element according to another embodiment of the present invention; Figure 4 is a schematic structural diagram of an angular velocity sensor according to an embodiment of the present invention; Figure 5 This is one of the schematic diagrams of the working principle of a gyro element according to an embodiment of the present invention; Figure 6 This is the second schematic diagram of the working principle of the gyro element according to an embodiment of the present invention.

[0017] Description of reference numerals: 1: gyro element; G: central island; 5a, 5b: detection fork fingers; 8a, 8b, 9a, 9b: driving fork fingers; 7a, 7b: connecting beams; 12a, 12b, 12c, 12d: electrical connecting beams; 14: inner frame; 15: outer frame; 13a, 13b, 13c, 13d: flexible connecting parts; 16, 17, 18, 19, 20, 21, 22, 23: wiring points; 6a, 6b, 10a, 10b, 11a, 11b: hammer head; 24: supporting base; 25: cover. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] It should be noted that some embodiments of the present invention are described below with reference to the accompanying drawings. However, the dimensions, materials, shapes, and relative configurations of the components described in the embodiments or shown in the accompanying drawings do not limit the scope of the present invention to these, but are merely illustrative examples.

[0020] Figure 1 FIG. 1 is a plan view of a gyro element according to an embodiment of the present invention. Figure 1 As shown, in one embodiment, the gyro element 1 includes: a central island G; detection fork fingers 5a, 5b, which are connected to the central island G; drive fork fingers 8a, 8b, 9a, 9b, which are connected to the central island G via connecting beams 7a, 7b; an inner frame 14, which surrounds the detection fork fingers 5a, 5b, the drive fork fingers 8a, 8b, 9a, 9b, and the central island G, and is connected to the central island G via electrical connecting beams 12a, 12b, 12c, 12d; an outer frame 15, which surrounds the inner frame 14, and is connected to the inner frame 14 via flexible connecting parts 13a, 13b, 13c, 13d located between the inner frame 14 and the outer frame 15; and wiring points 16-23, which are configured to electrically connect the outer frame 15 to the outside world.

[0021] Optionally, the gyro element 1 is an integrally formed quartz crystal structure, and a gold electrode layer is covered on its surface. The gyro element 1 works by utilizing the piezoelectric effect of quartz, is located in a plane formed by the X-axis and the Y-axis, and has a specified thickness in the Z-axis direction.

[0022] The working principle of the gyro element 1 in this embodiment is introduced below: Driven vibration mode: Figure 5 FIG. 1 is a schematic diagram of the working principle of a gyro element according to an embodiment of the present invention. Figure 5 As shown, when no angular velocity is applied from the outside, the gyro element 1 is in a driving vibration mode, and the driving voltage drives the forked fingers 8a, 8b, 9a, and 9b to move along the Figure 5 The bending vibration is in the direction of the arrow, and its vibration shape is symmetrical with respect to the Y axis of the center of gravity G.

[0023] Detection mode: Figure 6 FIG. 2 is a second schematic diagram of the working principle of a gyro element according to an embodiment of the present invention. Figure 6As shown, after applying voltage to the device, under the action of the inverse piezoelectric effect, the driving fork fingers 8a, 8b, 9a, 9b swing up and down in a circle with the center of gravity G as the center of the circle in the XY plane, and are in a driving vibration mode. At this time, if the gyro element 1 is subjected to a rotation with an angular velocity of ω around the Z axis, under the action of the Coriolis force, the vibration of the driving fork fingers 8a, 8b, 9a, 9b is transmitted to the detection fork fingers 5a, 5b via the connecting beams 7a, 7b, thereby driving the detection fork fingers 5a, 5b to swing in the plane where the X-axis and the Y-axis are located. Under the action of the piezoelectric effect, charges are accumulated on the surface of the detection fork fingers, and a DC voltage is output, and the output voltage is proportional to the angular velocity of rotation. The detection fork fingers are also called sensitive fork fingers. By detecting the electrical signals on the sensitive fork fingers, the angular velocity information of the rotation can be obtained.

[0024] According to the gyro element 1 in the present embodiment, there is a double-layer vibration reduction structure in the gyro element 1, and the double-layer vibration reduction structure is composed of an outer frame 15, an inner frame 14, electrical connection beams 12a, 12b, 12c, 12d, and wiring points 16-23, wherein the outer frame 15 is a rigid structure, which is used to support and fix the gyro element structure as a whole, and play an impact resistance role, and the flexible connection components 13a, 13b, 13c, 13d connecting the outer frame 15 and the inner frame 14 have low rigidity, which can effectively alleviate the vibration and impact transmitted from the outside, and has the function of isolating the external stress, and the inner frame 14 is a rigid structure, which serves as a buffer structure, plays a connecting and buffering role, and is used to further reduce the vibration transmitted into the inner frame 14.

[0025] In one possible implementation, the electrical signal is led from the central island 4 to the inner frame 14 via the electrical connection beams 12a, 12b, 12c, 12d, and then transmitted to the outer frame 15 via the flexible connection components 13a, 13b, 13c, 13d, and then transmitted to other electrical components for processing via the connection points 16-23 on the outer frame. On the contrary, interference from the outside, such as vibration and impact, will be transmitted through the double-layer vibration reduction structure composed of the outer frame 15, the flexible connection components 13a, 13b, 13c, 13d and the inner frame 14, and after being fully reduced, it will reach the relevant vibration components via the electrical connection beams 12a, 12b, 12c, 12d, so that the interference of external stress on the gyro element can be fully reduced. Thus, on the basis of solving the problem of connecting and fixing the gyro element to the outside world, the buffering of external interference is also achieved, thereby reducing the influence on the sensitivity of the gyro sensor.

[0026] In a possible implementation, in the gyro element 1, in the same plane, that is, in the xy plane, the central island G is located at the center of the gyro element 1, such as Figure 1As shown, a pair of detection forks 5a, 5b extend from the central island 4 in the positive and negative directions of the Y axis respectively, a pair of connecting beams 7a, 7b extend from the central island 4 in the positive and negative directions of the X axis respectively, two pairs of driving forks 8a, 8b, 9a, 9b are connected to the central island G via connecting beams 7a, 7b, and extend from one end of the connecting beams 7a, 7b in the positive and negative directions of the Y axis respectively, and each pair of driving forks is arranged parallel to both sides of the detection forks, that is, the detection forks 5a, 5b are arranged perpendicular to the connecting beams 7a, 7b, and the driving forks 8a, 8b, 9a, 9b are arranged perpendicular to the connecting beams 7a, 7b. Optionally, the inner frame 14 and the outer frame 15 are rotationally symmetrical with respect to the center of gravity of the gyro element 1.

[0027] By setting the positional relationship of the various components of the gyro element 1 as described above, it is ensured that when the gyro rotates around the Z axis, the center of gravity is always maintained at the center of the gyro element.

[0028] Optionally, the width of the driving fingers 8a, 8b, 9a, 9b is greater than the width of the detection fingers 5a, 5b, and the width of the detection fingers 5a, 5b is greater than the width of the electrical connection beams 12a, 12b, 12c, 12d. Since the width of the fingers will affect the frequency, by setting the width of each finger as described above, the driving frequency is less than the detection frequency, and the frequency difference can be guaranteed to be a certain value. At the same time, the electrical connection beam will not excessively affect the transmission of the vibration of the driving fingers to the detection fingers.

[0029] Optionally, the ends of the detection fingers 5a, 5b are formed into a hammer head shape, and the ends of the driving fingers 8a, 8b, 9a, 9b are formed into a hammer head shape.

[0030] By arranging the detection fingers and the driving fingers as described above, the detection fingers and the driving fingers can be rotationally symmetrical with respect to the center of gravity of the gyro element 1, thereby ensuring the mass balance of the gyro element as a whole, which helps to improve the gyro detection sensitivity. Figure 1 As shown, the detection fingers 5a, 5b include hammer heads 6a, 6b, and the driving fingers 8a, 8b, 9a, 9b include hammer heads 10a, 10b, 11a, 11b.

[0031] Figure 2 FIG. 1 is a plan view of a gyro element according to another embodiment of the present invention, wherein Figure 2 As shown, optionally, the wiring points 16 - 23 are wiring locations located on the outer frame 15 , configured to electrically connect the outer frame 15 to the outside.

[0032] Figure 3 FIG. 1 is a plan view of a gyro element according to another embodiment of the present invention, wherein Figure 3 As shown, optionally, the outer frame 15 is a frame-type component with chamfered corners.

[0033] Figure 4 FIG. 1 is a schematic diagram of the structure of an angular velocity sensor according to an embodiment of the present invention. Figure 4 As shown, in one embodiment, the angular velocity sensor includes: Gyro element 1; A support base 24, which is disposed below the gyro element 1 and includes a support edge electrically connected to the wiring points 16-23; and, The cover 25 is located above the gyro element and is combined with the support base to accommodate the gyro element.

[0034] The supporting edge can be used to support and fix the entire gyro element.

[0035] Optionally, the support base is made of ceramic, and the support edge is electrically connected to the wiring point via a conductive adhesive.

[0036] In the gyro element 1, the conductive adhesive bonds the outer frame 15 to the base 24, playing a role of fixing and restraining. Optionally, the conductive adhesive has a thickness of 10-20 μm.

[0037] An embodiment of the present invention further provides an electronic device, any one of the above-mentioned angular velocity sensors.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A gyro element, characterized in that: include: Central island; A detection fork finger, wherein the detection fork finger is connected to the central island; A driving fork finger, wherein the driving fork finger is connected to the central island via a connecting beam; An inner frame, which is a rigid structure, surrounds the detection fingers, the driving fingers and the central island, and is connected to the central island via an electrical connection beam; an outer frame, the outer frame being a rigid structure, surrounding the inner frame and connected to the inner frame via a flexible connecting member located between the inner frame and the outer frame; and A wiring point electrically connects the outer frame to the outside world.

2. The gyro element according to claim 1, characterized in that In the same plane, the central island is located at the center of the gyro element, a pair of the detection fork fingers extend from the central island in the positive and negative directions of the Y-axis respectively, two pairs of the driving fork fingers are arranged in parallel on both sides of the detection fork fingers, and each pair of driving fork fingers extend in the positive and negative directions of the Y-axis respectively, the connecting beam extends from the central island in the X-axis direction, the detection fork fingers are arranged perpendicularly to the connecting beam, the driving fork fingers are arranged perpendicularly to the connecting beam, and the electrical connecting beam is located between the detection fork fingers and the driving fork fingers.

3. The gyro element according to claim 2, characterized in that: The inner frame and the outer frame are rotationally symmetrical with respect to the center of gravity of the gyro element.

4. The gyro element according to claim 3, characterized in that: The width of the driving fingers is greater than the width of the detecting fingers, and the width of the detecting fingers is greater than the width of the electrical connection beam.

5. The gyro element according to claim 3 or 4, characterized in that: The ends of the detection fingers are shaped like hammer heads, and the ends of the driving fingers are shaped like hammer heads.

6. The gyro element according to claim 5, characterized in that The gyro element is an integrally formed quartz crystal structure, and a gold electrode layer is covered on the surface of the gyro element.

7. An angular velocity sensor, characterized in that: include: A gyroscopic element as claimed in any one of claims 1 to 6; a support base, the support base being disposed below the gyro element and comprising a support edge electrically connected to the wiring point; and A cover portion is located above the gyro element and is combined with the support base to accommodate the gyro element.

8. The angular velocity sensor according to claim 7, characterized in that: The support base is made of ceramic, and the support edge is electrically connected to the wiring point via a conductive adhesive.

9. The angular velocity sensor according to claim 7, characterized in that: The conductive adhesive has a thickness of 10-20 μm.

10. An electronic device, characterized in that: The angular velocity sensor comprising any one of claims 7 to 9.

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