Micromechanical gyroscope with multifunctional electrode

Abstract

The utility model discloses a micromechanical gyroscope with a multifunctional electrode. The micromechanical gyroscope consists of an electrode part on a substrate and a silicon structure layer, the silicon structure layer is integrally provided with a polycrystalline silicon chip, transverse extension arms and contact discs, the contact discs are arranged at the four corners of the polycrystalline silicon chip respectively and connected with the polycrystalline silicon chip through the transverse extension arms, and the polycrystalline silicon chip is arranged on the electrode part in a suspended mode and partially coincides and is opposite to the electrode part. The electrode part is composed of two driving electrodes, two detection electrodes and two supplementary electrodes which are independently arranged and respectively lead out a pin to the outside of the chip, the driving electrodes are arranged corresponding to the edge of the polycrystalline silicon chip, and the supplementary electrodes are arranged between the two detection electrodes side by side. According to the micromechanical gyroscope, the four-electrode layout is optimized, pins and electrodes do not need to be specially reserved for each functional area, the chip size is reduced, the cost is reduced, coupling signal crosstalk is reduced, and the precision and performance of the gyroscope are improved; through multifunctional energizing of the supplementary electrode, the micromechanical gyroscope can meet various working conditions.

Description

Technical Field

[0001] The utility model relates to a micro-electromechanical gyroscope, in particular to a micro-mechanical gyroscope with multifunctional electrodes, and belongs to the field of semiconductor integrated devices. Background Art

[0002] MEMS (Micro Electro-Mechanical System) refers to miniaturized devices or combinations of devices, creating integrated systems that combine electronic with mechanical, optical, or other functions. Their miniaturized structure enables intelligent functionality within a minimal space. Currently, MEMS gyroscopes are widely used in consumer electronics such as smartphones, tablets, and watches, enabling applications such as motion-sensing gaming and fall detection. In recent years, with the increasing demand for intelligent vehicles, inertial navigation systems (INS) based on MEMS gyroscopes have gradually gained traction.

[0003] Currently, as the market demands more and more from gyroscope chips, numerous features are being incorporated, such as modal matching, quadrature compensation, increasing capacitance to enhance sensitivity, and reducing the effects of negative electrostatic stiffness. Typically, designers need to leave ample space for pins and electrodes for each function to ensure that these functions can be met during subsequent testing and use. This often requires significant space, which inadvertently increases costs. Excessive traces can also increase parasitic parameters and degrade gyroscope performance. Summary of the Invention

[0004] The purpose of the utility model is to provide a micro-mechanical gyroscope with multifunctional electrodes, so as to solve the problem of simplifying large-area wiring of a gyroscope chip and reducing the chip size.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a micromechanical gyroscope with a multifunctional electrode, which is composed of an electrode portion and a silicon structure layer on a substrate, wherein the silicon structure layer is integrally formed with a polycrystalline silicon wafer, a lateral arm and a contact plate, wherein the contact plate is arranged at the four corners of the polycrystalline silicon wafer and is connected to the polycrystalline silicon wafer through the lateral arm, and the polycrystalline silicon wafer is arranged above the electrode portion in a suspended state and most of them overlap and are opposite to each other, and is characterized in that: the electrode portion is composed of two independently arranged driving electrodes, each of which leads a pin to the outside of the chip, two detection electrodes and two supplementary electrodes, wherein the driving electrode is arranged corresponding to the edge of the polycrystalline silicon wafer, and the supplementary electrode is located between the two detection electrodes in a side-by-side state.

[0006] Furthermore, the area ratio of a single supplementary electrode to the detection electrode is 1:4.

[0007] Furthermore, the supplementary electrode is electrically connected to the detection electrode.

[0008] Furthermore, the polycrystalline silicon wafer is provided with a hollowed-out strip groove at a position corresponding to the supplementary electrode, and the supplementary electrode is configured as an orthogonal compensation electrode.

[0009] Furthermore, the supplementary electrode applies a DC voltage to adjust the electrostatic force facing the polycrystalline silicon wafer.

[0010] Compared with the prior art, the beneficial effects of the present invention are as follows: the micromechanical gyroscope optimizes the four-electrode layout, and there is no need to reserve pins and electrodes for each functional area separately, which is conducive to reducing chip size, reducing costs and reducing coupled signal crosstalk, and improving gyroscope accuracy and performance; through the multifunctional empowerment of the supplementary electrode, the micromechanical gyroscope can meet a variety of working conditions. For example, when a DC voltage is applied to the supplementary electrode, the electrostatic force between the polysilicon wafer and the detection electrode can be adjusted, thereby adjusting the electrical stiffness and detection modal frequency of the system, and improving the corresponding rate and sensitivity of the detection output. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic top view of a preferred embodiment of the micro-mechanical gyroscope of the present invention.

[0012] Figure 2 It is a schematic top view of another embodiment of the micro-mechanical gyroscope of the present invention. DETAILED DESCRIPTION

[0013] The specific implementation methods of the present invention will be further described below in conjunction with the accompanying drawings of the embodiments, so that the technical solution of the present invention is easier to understand and grasp, thereby making a clearer definition of the protection scope of the present invention.

[0014] Considering that the current micromechanical gyroscopes require functional expansion in their design but the pins and electrode wiring occupy too large a chip area, the utility model innovatively proposes a micromechanical gyroscope with multifunctional electrodes to optimize the chip structure, reduce signal coupling in the case of large-area wiring, thereby reducing chip manufacturing costs and improving gyroscope accuracy.

[0015] like Figure 1Figure 2 shows a schematic top view of the preferred embodiment of the micromechanical gyroscope of the present invention. The structure generally consists of an electrode portion 3 on a substrate 1 and a silicon structure layer 2. As the silicon structure layer within the gyroscope chip, which experiences significant changes in static and dynamic states, it integrally comprises a polycrystalline silicon wafer 21, a transverse arm 22, and a contact plate 23. Spatially, the contact plates 23 are located outside the four corners of the polycrystalline silicon wafer 21 and connected to it via the transverse arm 22, allowing the polycrystalline silicon wafer 21 to be suspended above the electrode portion, with most portions overlapping and facing each other. This allows the polycrystalline silicon wafer 21 to periodically oscillate in a direction perpendicular to the transverse arm and to periodically float and rise in a direction perpendicular to the substrate plane. The relatively stationary electrode portion 3 within the gyroscope chip consists of two independently disposed drive electrodes 4, each with a lead pin extending to the outside of the chip, two detection electrodes 31, and two supplementary electrodes 32. From the perspective of the diagram, the polycrystalline silicon wafer is formed with comb-shaped drive sensing portions 211 on the upper and lower sides, and the drive electrodes 4 are located at the corresponding edge positions of the polycrystalline silicon wafer 21. When a DC voltage is injected into the polycrystalline silicon wafer and an AC signal with the same structural natural frequency is injected into the comb portion of the drive electrode, the gyroscope is driven, causing the polycrystalline silicon wafer to reciprocate in the vertical direction. When there is a left or right lateral angular velocity input, the Coriolis force causes the central polycrystalline silicon wafer to shift back and forth in the direction of vision, moving closer or further away. This displacement changes the distance relative to the detection electrode, causing the mutual capacitance to change. By detecting the change in capacitance, the angular velocity input value can be obtained. The supplementary electrode 32 is located side by side between the two detection electrodes.

[0016] From a more detailed structural perspective, the area ratio of the single supplementary electrode 32 to the detection electrode 31 may be 1:4. Of course, the relative sizes may be appropriately adjusted during the manufacture of specific products, and there is no limitation thereto.

[0017] Compared to traditional micromechanical gyroscopes, this supplementary electrode provides the gyroscope chip with optional multifunctional implementation, as follows:

[0018] First, as a first application, the supplementary electrode can be directly electrically connected to the adjacent detection electrode to form an integral whole, and only serves as a supplement to detect the capacitance change.

[0019] Secondly, as the second application, such as Figure 2 In the embodiment shown, a hollowed-out strip groove 212 may be provided at the location of the polysilicon wafer 21 corresponding to the location of the supplementary electrode, thereby making it (ie, the supplementary electrode) an orthogonal compensation electrode and realizing the corresponding function.

[0020] Furthermore, as a third application, a DC voltage can be applied directly to the supplementary electrode. Adjusting the voltage can alter the electrostatic force between it and the polysilicon wafer. This electrostatic force reduces the system's electrical stiffness and the detection modal frequency, thereby improving the detection output response and sensitivity, and even entering a modal matching mode.

[0021] From the above introduction to the scheme and detailed description of the embodiments of the micromechanical gyroscope of the utility model, it can be seen that the chip structure has substantial characteristics and progress: the four-electrode layout is optimized, and there is no need to reserve pins and electrodes separately for each functional area, which is conducive to reducing chip size, reducing costs and reducing coupled signal crosstalk, and improving gyroscope accuracy and performance; through the multifunctional empowerment of the supplementary electrode, the micromechanical gyroscope can meet a variety of working conditions. For example, when a DC voltage is applied to the supplementary electrode, the electrostatic force between the polysilicon wafer and the detection electrode can be adjusted, thereby adjusting the electrical stiffness and detection modal frequency of the system, and improving the corresponding rate and sensitivity of the detection output.

[0022] In addition to the above embodiments, the present invention may also have other implementation methods. Any technical solutions formed by equivalent replacement or equivalent transformation fall within the scope of protection required by the present invention.

Claims

1. A micromechanical gyroscope with multifunctional electrodes, comprising an electrode portion and a silicon structure layer on a substrate. The silicon structure layer is integrally formed with a polycrystalline silicon wafer, a transverse arm, and a contact plate. The contact plates are located at the four corners of the polycrystalline silicon wafer and connected to the polycrystalline silicon wafer via the transverse arm. The polycrystalline silicon wafer is suspended above the electrode portion, with most portions overlapping and facing each other. The invention is characterized by: The electrode part consists of two independently arranged driving electrodes, each with a pin extending to the outside of the chip, two detection electrodes and two supplementary electrodes, wherein the driving electrodes are arranged corresponding to the edge of the polysilicon wafer, and the supplementary electrodes are located between the two detection electrodes in a side-by-side manner.

2. The micromechanical gyroscope with multifunctional electrodes according to claim 1, characterized in that: The area ratio of a single supplementary electrode to the detection electrode is 1:

4.

3. The micromechanical gyroscope with multifunctional electrodes according to claim 1, characterized in that: The supplementary electrode is electrically connected to the detection electrode.

4. The micromechanical gyroscope with multifunctional electrodes according to claim 1, characterized in that: The polycrystalline silicon wafer is provided with a hollowed-out strip groove at a position corresponding to the supplementary electrode, and the supplementary electrode is configured as an orthogonal compensation electrode.

5. The micromechanical gyroscope with multifunctional electrodes according to claim 1, characterized in that: The supplementary electrode applies a DC voltage to adjust the electrostatic force facing the polysilicon wafer.

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