Inertial acceleration sensor with multiple measuring ranges and double detection modes

Abstract

The invention relates to the technical field of semiconductor manufacturing, in particular to a multi-range dual-detection-mode inertial acceleration sensor which comprises a substrate, a device layer and an upper cover plate. The detection unit is used for performing open-loop and / or closed-loop detection on the acceleration; and the driving feedback capacitor is used for providing electrostatic force to balance the movement of the mass frame when the detection unit performs closed-loop detection. According to the inertial acceleration sensor, different detection modes can be adopted under different ranges, open-loop detection is carried out through the detection unit in the low range, closed-loop detection is carried out through cooperation of the detection unit and the driving feedback capacitor in the high range, the accuracy of the detection result is higher, and the detection precision is higher. Moreover, the open-closed loop detection of the acceleration is realized in one structure, the size and weight of the sensor can be reduced, and the cost is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of semiconductor manufacturing, and in particular to an inertial acceleration sensor with a multi-range dual-detection mode. Background Art

[0002] Open-loop detection devices are easy to measure, but if they are subjected to a large load, electrostatic attraction will occur between the plate and the fixed plate, causing a short circuit and device failure. Therefore, open-loop detection is generally suitable for situations with a smaller range. Closed-loop detection can connect the input voltage as a feedback signal to the sensitive structure, forming a feedback electrostatic force with the bias voltage in the sensitive structure, making the mass frame tend to return to the initial position, avoiding electrostatic attraction, and increasing the range and reliability of the device.

[0003] Existing inertial acceleration sensors can generally only perform open-loop detection or closed-loop detection. Usually, two types of accelerometers are set up. An open-loop detection accelerometer is used for detection at a low range, and a closed-loop detection accelerometer is used for detection at a high range. This is not only costly, but also occupies a large space, which is not conducive to the miniaturization of the device. Summary of the invention

[0004] The object of the present invention is to provide an inertial acceleration sensor with a multi-range dual-detection mode, which can realize both open-loop detection and closed-loop detection, has a higher accuracy of detection results, lower cost and smaller size.

[0005] To achieve the above object, the technical solution of the present invention is an inertial acceleration sensor with a multi-range dual-detection mode, comprising a substrate, a device layer and an upper cover plate, wherein the device layer comprises:

[0006] Quality frame;

[0007] A detection unit, used for performing open-loop and / or closed-loop detection of acceleration;

[0008] The driving feedback capacitor is used to provide an electrostatic force to balance the movement of the mass frame when the detection unit performs closed-loop detection.

[0009] As one of the implementation modes, the mass frame includes a first frame and a second frame, and both the first frame and the second frame are two and are arranged opposite to each other;

[0010] X-direction differential detection capacitors are respectively provided on both sides of each of the first frames for detecting the X direction;

[0011] Y-direction differential detection capacitors are respectively provided on both sides of each of the second frames for detecting the Y direction.

[0012] As one of the implementation modes, the inner area surrounded by the mass frame is further provided with a partition beam parallel to the first frame, and the two sides of the partition beam are respectively provided with the X-direction differential detection capacitor, or

[0013] A partition beam parallel to the second frame is provided, and the Y-direction differential detection capacitors are respectively provided on both sides of the partition beam.

[0014] As one of the implementation modes, when the detection unit performs open-loop detection in the X direction, the detection unit performs open-loop or closed-loop detection in the Y direction;

[0015] When the detection unit performs closed-loop detection in the X direction, the detection unit performs open-loop or closed-loop detection in the Y direction.

[0016] As one of the implementation modes, when the detection unit is a closed-loop detection in the X direction, the X-direction differential detection capacitor in the inner or outer area of ​​the mass frame constitutes the detection unit, and the X-direction differential detection capacitor in another area constitutes the drive feedback unit, or

[0017] When the detection unit performs closed-loop detection in the Y direction, the Y-direction differential detection capacitor in the inner or outer area of ​​the mass frame constitutes the detection unit, and the Y-direction differential detection capacitor in another area constitutes the drive feedback unit.

[0018] As one of the implementation modes, the capacitance change directions of the X-direction differential detection capacitors on both sides of the first frame are opposite, or the capacitance change directions of the X-direction differential detection capacitors on the same side of the first frame are opposite; the two X-direction differential detection capacitors with opposite capacitance change directions constitute a group of X-direction differential detection capacitor pairs, and the detection unit includes at least one group of X-direction differential detection capacitor pairs;

[0019] The capacitance change directions of the Y-direction differential detection capacitors on both sides of the second frame are opposite, or the capacitance change directions of the Y-direction differential detection capacitors on the same side of the second frame are opposite; the two Y-direction differential detection capacitors with opposite capacitance change directions constitute a group of Y-direction differential detection capacitor pairs, and the detection unit includes at least one group of Y-direction differential detection capacitor pairs.

[0020] As one of the implementation modes, the device layer further includes a Z-direction detection structure, and the Z-direction detection structure is a parallel plate capacitor structure including a first plate and a second plate.

[0021] As one of the implementation modes, the first electrode plate is the device layer, and the second electrode plate is the upper cover plate.

[0022] As one of the implementation modes, the mass frame is connected to anchor points on the substrate via a plurality of spring beams.

[0023] As one of the implementation modes, the arrangement direction of the spring beam forms a certain angle with both the X direction and the Y direction, or the spring beam includes an X-direction spring beam arranged along the X direction and a Y-direction spring beam arranged along the Y direction.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] (1) The inertial acceleration sensor of the present invention can adopt different detection methods under different ranges. In low ranges, open-loop detection is performed by the detection unit, and in high ranges, closed-loop detection is performed by the detection unit in cooperation with the drive feedback capacitor. The detection result has higher accuracy, and the open-loop and closed-loop detection of acceleration is realized in one structure, which can reduce the volume and weight of the sensor and reduce the cost.

[0026] (2) The present invention adopts a differential method to measure acceleration in both the X direction and the Y direction, which can effectively reduce the measurement error and maintain good linearity.

[0027] (3) The present invention realizes acceleration open-loop and closed-loop detection in the X direction and the Y direction in one structure, has a compact architecture, and can effectively reduce the device area, save space, and reduce costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only 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.

[0029] Figure 1 A schematic diagram of an inertial acceleration sensor with a multi-range dual-detection mode provided by an embodiment of the present invention;

[0030] Figure 2 A schematic diagram of an inertial acceleration sensor with a multi-range dual-detection mode provided by an embodiment of the present invention;

[0031] Figure 3 An exploded diagram of an inertial acceleration sensor with a multi-range dual-detection mode provided in an embodiment of the present invention;

[0032] Figure 4 A schematic diagram of an inertial acceleration sensor with a multi-range dual-detection mode provided by an embodiment of the present invention;

[0033] Figure 5 A schematic diagram of an inertial acceleration sensor with a multi-range dual-detection mode provided by an embodiment of the present invention;

[0034] Figure 6A schematic diagram of another multi-range dual-detection inertial acceleration sensor provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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.

[0036] In the description of the present invention, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0037] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features; in the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0038] like Figure 1-Figure 5 As shown, this embodiment provides an inertial acceleration sensor with a multi-range dual-detection mode, including a substrate 1, a device layer 2 and an upper cover plate 3, wherein the device layer 2 includes:

[0039] Quality box 6;

[0040] A detection unit, used for performing open-loop and / or closed-loop detection of acceleration;

[0041] The driving feedback capacitor is used to provide an electrostatic force to balance the movement of the mass frame 6 when the detection unit performs closed-loop detection.

[0042] The inertial acceleration sensor of this embodiment can adopt different detection methods under different ranges. In the low range, open-loop detection is performed by the detection unit, and in the high range, closed-loop detection is performed by the detection unit in cooperation with the drive feedback capacitor. The detection result has higher accuracy, and the open-loop and closed-loop detection of acceleration is realized in one structure, which can reduce the size and weight of the sensor and reduce costs.

[0043] In some embodiments, the mass frame 6 includes a first frame 7 and a second frame 8, and both the first frame 7 and the second frame 8 are two and are arranged opposite to each other;

[0044] X-direction differential detection capacitors are respectively provided on both sides of each of the first frames 7 for detecting the X direction;

[0045] Y-direction differential detection capacitors are respectively provided on both sides of each second frame 8 for detecting the Y direction.

[0046] In one embodiment, the inner area surrounded by the mass frame 6 is further provided with a partition beam 14 parallel to the first frame 7, and the two sides of the partition beam 14 are respectively provided with the X-direction differential detection capacitor. Figure 1 As shown, the quality frame 6 is of a sun type, the separation beam 14 is parallel to the first frame 7, and the two sides of the separation beam 14 are respectively provided with X-direction differential detection capacitors.

[0047] In another embodiment, the inner area surrounded by the mass frame 6 is further provided with a separation beam parallel to the second frame 8 , and the Y-direction differential detection capacitors are respectively provided on both sides of the separation beam.

[0048] In this embodiment, when the detection unit performs open-loop detection in the X direction, the detection unit performs open-loop or closed-loop detection in the Y direction;

[0049] When the detection unit performs closed-loop detection in the X direction, the detection unit performs open-loop or closed-loop detection in the Y direction.

[0050] Specifically, when the acceleration in the X direction is small, the detection unit performs open-loop detection on the acceleration in the X direction, and when the acceleration in the X direction is large, the detection unit performs closed-loop detection on the acceleration in the X direction; when the acceleration in the Y direction is small, the detection unit performs open-loop detection on the acceleration in the Y direction, and when the acceleration in the Y direction is large, the detection unit performs closed-loop detection on the acceleration in the Y direction. The inertial acceleration sensor of this embodiment realizes open-loop and closed-loop detection of acceleration in the X direction and the Y direction in one structure at the same time, and has a compact architecture, which can effectively reduce the device area, save space, and reduce costs.

[0051] In some embodiments, when the detection unit is closed-loop detection in the X direction, the X-direction differential detection capacitor in the inner or outer area of ​​the mass frame 6 constitutes the detection unit, and the X-direction differential detection capacitor in another area constitutes the drive feedback unit, or

[0052] When the detection unit performs closed-loop detection in the Y direction, the Y-direction differential detection capacitor in the inner or outer area of ​​the mass frame 6 constitutes the detection unit, and the Y-direction differential detection capacitor in another area constitutes the drive feedback unit.

[0053] The inertial acceleration sensor of this embodiment performs closed-loop detection through the cooperation of the detection unit and the drive feedback capacitor at high range, and the detection unit and the drive feedback unit are separated, and differential detection capacitors in different areas are used respectively, which can reduce mutual interference and noise within the system and make the detection result more reliable.

[0054] In this embodiment, the capacitance change directions of the X-direction differential detection capacitors on both sides of the first frame 7 are opposite, or the capacitance change directions of the X-direction differential detection capacitors on the same side of the first frame 7 are opposite; the two X-direction differential detection capacitors with opposite capacitance change directions constitute a group of X-direction differential detection capacitor pairs, and the detection unit includes at least one group of X-direction differential detection capacitor pairs;

[0055] The capacitance change directions of the Y-direction differential detection capacitors on both sides of the second frame 8 are opposite, or the capacitance change directions of the Y-direction differential detection capacitors on the same side of the second frame 8 are opposite; the two Y-direction differential detection capacitors with opposite capacitance change directions constitute a group of Y-direction differential detection capacitor pairs, and the detection unit includes at least one group of Y-direction differential detection capacitor pairs.

[0056] like Figure 1As shown, a first X-direction differential detection capacitor 15 and a second X-direction differential detection capacitor 16 are respectively arranged on both sides of the first frame 7 on the upper side, and the directions of capacitance change of the two are opposite; a second X-direction differential detection capacitor 17 and a first X-direction differential detection capacitor 18 are respectively arranged on both sides of the first frame 7 on the lower side, and the directions of capacitance change of the two are opposite; and the first X-direction differential detection capacitor 15 and the second X-direction differential detection capacitor 17 are located in the outer frame area of ​​the quality frame 6, and the second X-direction differential detection capacitor 16 and the first X-direction differential detection capacitor 18 are located in the inner frame area of ​​the quality frame 6. When subjected to a relatively small load in the X direction, the inertial acceleration sensor of the present embodiment can be used as an open-loop device for open-loop detection. The first X-direction differential detection capacitor 15 and the second X-direction differential detection capacitor 16 constitute a group of X-direction differential detection capacitor pairs, and the second X-direction differential detection capacitor 17 and the first X-direction differential detection capacitor 18 constitute a group of X-direction differential detection capacitor pairs. The two groups of X-direction differential detection capacitor pairs perform acceleration detection in the X direction in a differential manner. The structure also adopts a variable area detection method, which can increase the linearity of the device. When subjected to a large load in the X direction, the inertial acceleration sensor of the present embodiment can be used as a closed-loop device for closed-loop detection. The second X-direction differential detection capacitor 16 and the first X-direction differential detection capacitor 18 in the inner region of the mass frame 6 can constitute an X-direction drive feedback capacitor to provide the device with an electrostatic force in the X direction to balance the movement of the device. The first X-direction differential detection capacitor 15 and the second X-direction differential detection capacitor 17 in the outer region of the mass frame 6 constitute a group of X-direction differential detection capacitor pairs, and acceleration detection in the X direction is performed in a differential manner. The structure also adopts a variable area detection method, which can increase the linearity of the device. Alternatively, the first X-direction differential detection capacitor 15 and the second X-direction differential detection capacitor 17 in the outer region of the mass frame 6 constitute an X-direction drive feedback capacitor to provide the device with an electrostatic force in the X direction to balance the movement of the device. The second X-direction differential detection capacitor 16 and the first X-direction differential detection capacitor 18 in the inner region of the mass frame 6 constitute a group of X-direction differential detection capacitor pairs, and acceleration detection in the X direction is performed in a differential manner.

[0057] In this embodiment, the first X-direction differential detection capacitor and the second X-direction differential detection capacitor both include X-direction movable comb teeth 9 and X-direction fixed comb teeth 10 in a comb-tooth-matched manner, and are used to measure the acceleration signal in the X direction; wherein the X-direction movable comb teeth 9 are fixed on the first frame 7, and the X-direction fixed comb teeth 10 are fixed on the substrate 1 through anchor points or anchor areas 45.

[0058] In one embodiment, if Figure 1As shown, the quality frame 6 is of a day type, and a second X-direction differential detection capacitor 19 and a first X-direction differential detection capacitor 20 are respectively arranged on both sides of the separation beam 14, and the capacitance change directions of the two are opposite; and the second X-direction differential detection capacitor 19 and the first X-direction differential detection capacitor 20 are both located in the frame area of ​​the quality frame 6, the X-direction fixed comb teeth 10 of the second X-direction differential detection capacitor 19 and the X-direction fixed comb teeth 10 of the second X-direction differential detection capacitor 16 are fixed to the substrate 1 through the anchor area 45, and the X-direction fixed comb teeth 10 of the first X-direction differential detection capacitor 20 and the X-direction fixed comb teeth 10 of the first X-direction differential detection capacitor 18 are fixed to the substrate 1 through the anchor area 45. When subjected to a relatively small load in the X direction, the inertial acceleration sensor of the present embodiment can be used as an open-loop device for open-loop detection. The first X-direction differential detection capacitor 15 and the second X-direction differential detection capacitor 16 constitute a group of X-direction differential detection capacitor pairs, the second X-direction differential detection capacitor 17 and the first X-direction differential detection capacitor 18 constitute a group of X-direction differential detection capacitor pairs, and the second X-direction differential detection capacitor 19 and the first X-direction differential detection capacitor 20 constitute a group of X-direction differential detection capacitor pairs. The three groups of X-direction differential detection capacitor pairs perform acceleration detection in the X direction in a differential manner. The structure also adopts a variable area detection method, which can increase the linearity of the device. When subjected to a large load in the X direction, the inertial acceleration sensor of this embodiment can be used as a closed-loop device for closed-loop detection. The second X-direction differential detection capacitor 16, the first X-direction differential detection capacitor 18, the second X-direction differential detection capacitor 19 and the first X-direction differential detection capacitor 20 in the inner region of the mass frame 6 constitute an X-direction drive feedback capacitor, which provides an X-direction electrostatic force to balance the movement of the device. The first X-direction differential detection capacitor 15 and the second X-direction differential detection capacitor 17 in the outer region of the mass frame 6 constitute a group of X-direction differential detection capacitor pairs, which perform acceleration detection in the X direction in a differential manner. The structure also adopts a variable area detection method, which can increase the linearity of the device, or the first X-direction differential detection capacitor 15 and the second X-direction differential detection capacitor 17 in the outer area of ​​the mass frame 6 are used as X-direction drive feedback capacitors to provide the device with an X-direction electrostatic force balance to balance the operation of the device, the second X-direction differential detection capacitor 16 and the first X-direction differential detection capacitor 18 in the inner area of ​​the mass frame 6 constitute a group of X-direction differential detection capacitor pairs, and the second X-direction differential detection capacitor 19 and the first X-direction differential detection capacitor 20 constitute a group of X-direction differential detection capacitor pairs, and acceleration detection in the X direction is performed in a differential manner.

[0059] like Figure 1As shown, a first Y-direction differential detection capacitor 29 and a second Y-direction differential detection capacitor 30 are provided on one side of the second frame 8 on the left, and the directions of capacitance change of the two are opposite; a first Y-direction differential detection capacitor 31 and a second Y-direction differential detection capacitor 32 are provided on the other side of the second frame 8 on the left, and the directions of capacitance change of the two are opposite; a first Y-direction differential detection capacitor 33 and a first Y-direction differential detection capacitor 34 are provided on one side of the second frame 8 on the right, and the directions of capacitance change of the two are opposite; a second Y-direction differential detection capacitor 35 and a second Y-direction differential detection capacitor 36 are provided on the other side of the second frame 8 on the right, and the directions of capacitance change of the two are opposite; and the first Y-direction differential detection capacitor 29, the second Y-direction differential detection capacitor 30, the second Y-direction differential detection capacitor 35 and the second Y-direction differential detection capacitor 36 are located in the outer region of the quality frame 6, and the first Y-direction differential detection capacitor 31, the second Y-direction differential detection capacitor 32, the first Y-direction differential detection capacitor 33 and the first Y-direction differential detection capacitor 34 are located in the inner region of the quality frame 6. When subjected to a smaller load in the Y direction, the inertial acceleration sensor of the present embodiment can be used as an open-loop device for open-loop detection. The first Y-direction differential detection capacitor 29 and the second Y-direction differential detection capacitor 30 constitute a group of Y-direction differential detection capacitor pairs, the first Y-direction differential detection capacitor 31 and the second Y-direction differential detection capacitor 32 constitute a group of Y-direction differential detection capacitor pairs, the first Y-direction differential detection capacitor 33 and the first Y-direction differential detection capacitor 34 constitute a group of Y-direction differential detection capacitor pairs, the second Y-direction differential detection capacitor 35 and the second Y-direction differential detection capacitor 36 constitute a group of Y-direction differential detection capacitor pairs, and acceleration detection in the Y direction is performed in a differential manner. The structure also adopts a variable area detection method, which can increase the linearity of the device.When subjected to a large load in the Y direction, the inertial acceleration sensor of the present embodiment can be used as a closed-loop device for closed-loop detection. The first Y-direction differential detection capacitor 31, the second Y-direction differential detection capacitor 32, the first Y-direction differential detection capacitor 33 and the first Y-direction differential detection capacitor 34 in the inner region of the mass frame 6 constitute a Y-direction drive feedback capacitor, which provides an electrostatic force in the Y direction to balance the movement of the device. The first Y-direction differential detection capacitor 29 and the second Y-direction differential detection capacitor 30 in the outer region of the mass frame 6 constitute a group of Y-direction differential detection capacitor pairs, and the second Y-direction differential detection capacitor 35 and the second Y-direction differential detection capacitor 36 constitute a group of Y-direction differential detection capacitor pairs, which detect acceleration in the Y direction in a differential manner. The structure also adopts a variable The detection method of area can increase the linearity of the device; or the first Y-direction differential detection capacitor 29, the second Y-direction differential detection capacitor 30, the second Y-direction differential detection capacitor 35 and the second Y-direction differential detection capacitor 36 in the outer area of ​​the mass frame 6 constitute a Y-direction drive feedback capacitor, which provides an electrostatic force in the Y direction to balance the movement of the device, and the first Y-direction differential detection capacitor 31 and the second Y-direction differential detection capacitor 32 in the inner area of ​​the mass frame 6 constitute a group of Y-direction differential detection capacitor pairs, and the second Y-direction differential detection capacitor 33 and the second Y-direction differential detection capacitor 34 constitute a group of Y-direction differential detection capacitor pairs, and the acceleration detection in the Y direction is performed in a differential manner. The structure also adopts a variable area detection method, which can increase the linearity of the device.

[0060] In this embodiment, the detection unit uses a differential method to measure acceleration, which can effectively reduce measurement errors and maintain good linearity.

[0061] In this embodiment, the first Y-direction differential detection capacitor and the second Y-direction differential detection capacitor both include Y-direction movable comb teeth 11 and Y-direction fixed comb teeth 12 in a comb-tooth-like configuration, and are used to measure acceleration signals in the Y direction; wherein the Y-direction movable comb teeth 11 are fixed on the second frame 8, and the Y-direction fixed comb teeth 12 are fixed on the base 1 through anchor points or anchor areas 45.

[0062] In one embodiment, the device layer 2 further includes a Z-direction detection structure, which is a parallel plate capacitor structure including a first plate and a second plate. The inertial acceleration sensor of this embodiment can also measure acceleration in the Z-axis direction.

[0063] The above embodiment is optimized, the first electrode is the device layer 2, and the second electrode is the upper cover 3. The bottom surface of the upper cover 3 has a square conductive area of ​​the same size as the mass frame 6, which serves as the Z-axis detection layer 4. The upper cover 3 is also used as the second electrode, which can reduce the size of the inertial device and reduce the cost of the inertial device.

[0064] like Figure 4As shown, an anchor layer 5 is provided between the device layer 2 and the substrate 1 , and the anchor layer 5 includes anchors and anchor regions 45 for fixing the X-direction fixed comb teeth 10 , anchors for fixing the Y-direction fixed comb teeth 12 , and anchors for fixing the spring beams 13 .

[0065] like Figure 1-Figure 4 As shown, the mass frame 6 is connected to the anchor points on the substrate 1 through a plurality of spring beams 13. In this embodiment, the mass frame 6 is a square frame, and the four corners of the mass frame 6 are connected to the four anchor points on the substrate 1 through four spring beams 13 respectively.

[0066] In one embodiment, if Figure 1 As shown, the arrangement direction of the spring beam 13 forms a certain angle with both the X direction and the Y direction. Preferably, each spring beam 13 is arranged along the extended diagonal line of the corresponding corner of the mass frame 6. Further optimized, the mass frame 6 is a square frame, and each spring beam 13 has the same angle with the first frame 7 and the second frame 8 at the connection. The spring beam 13 is suspended at the four corners of the mass frame 6 at 45°, so that the mass frame 6 can move in the X direction and the Y direction at the same time.

[0067] In another embodiment, if Figure 5 As shown, the spring beam 13 includes an X-direction spring beam 43 arranged along the X direction and a Y-direction spring beam 44 arranged along the Y direction. Each corner of the mass frame 6 is connected with an X-direction spring beam 43 and a Y-direction spring beam 44, and an anchor point corresponding to each X-direction spring beam 43 and each Y-direction spring beam 44 is provided on the base 1, and one end of the X-direction spring beam 43 and one end of the Y-direction spring beam 44 are respectively connected to the first frame 7 and the second frame 8 at the corner position of the mass frame 6, and the other end of the X-direction spring beam 43 and the other end of the Y-direction spring beam 44 are respectively connected to the corresponding anchor points on the base 1.

[0068] The spring beam 13 in the above two embodiments also has a degree of freedom in the Z-axis direction, and the mass frame 6 and the upper cover plate 3 above it form a parallel plate capacitor structure. Initially, the distance between the mass frame 6 and the upper cover plate 3 is d, and the capacitance value at this time is C = εA / d; when there is a load in the Z direction, the mass frame 6 moves d1 in the Z-axis direction, and at this time, the distance between the mass frame 6 and the upper cover plate 3 becomes d 11 =d-d1, the capacitance value is C1=εA / (d-d1), so the load in the Z-axis direction can be measured by measuring the capacitance value.

[0069] In this embodiment, the first frame 7 can be parallel to the X direction, and the second frame 8 can be parallel to the Y direction. Figure 1 and Figure 5 As shown; the first frame 7 can also be perpendicular to the X direction, and the second frame 8 can be perpendicular to the Y direction, such as Figure 6In both modes, the comb teeth of the X-direction movable comb teeth 9 and the X-direction fixed comb teeth 10 are parallel to the X direction, and the comb teeth of the Y-direction movable comb teeth 11 and the Y-direction fixed comb teeth 12 are parallel to the Y direction.

[0070] In this embodiment, when the first frame 7 is parallel to the X direction and the second frame 8 is parallel to the Y direction, the partition beam 14 is parallel to the X direction, and X-direction differential detection capacitors are arranged on both sides. Figure 1 and Figure 5 When the first frame 7 is perpendicular to the X direction and the second frame 8 is perpendicular to the Y direction, the partition beam 14 is parallel to the X direction, and Y-direction differential detection capacitors are set on both sides, such as Figure 6 shown.

[0071] Below Figure 6 The structure and principle of the inertial acceleration sensor are explained in detail.

[0072] Figure 6 The first frame 7 of the inertial acceleration sensor in the figure is perpendicular to the X direction, and the two sides of the upper part of the first frame 7 on the left side are respectively provided with a second X-direction differential detection capacitor 21 and a first X-direction differential detection capacitor 22, and the capacitance change directions of the two are opposite; the two sides of the lower part are respectively provided with a second X-direction differential detection capacitor 23 and a first X-direction differential detection capacitor 24, and the capacitance change directions of the two are opposite; the two sides of the upper part of the first frame 7 on the right side are respectively provided with a second X-direction differential detection capacitor 25 and a first X-direction differential detection capacitor 26, and the capacitance change directions of the two are opposite; the two sides of the lower part are respectively provided with a second X-direction differential detection capacitor 26. The second X-direction differential detection capacitor 27 and the first X-direction differential detection capacitor 28 have opposite capacitance change directions; the first Y-direction differential detection capacitor 37 and the second Y-direction differential detection capacitor 38 are respectively arranged on both sides of the second frame 8 on the upper side, and the capacitance change directions of the two are opposite; the first Y-direction differential detection capacitor 39 and the second Y-direction differential detection capacitor 40 are respectively arranged on both sides of the partition beam 14, and the capacitance change directions of the two are opposite; the first Y-direction differential detection capacitor 41 and the second Y-direction differential detection capacitor 42 are respectively arranged on both sides of the second frame 8 on the lower side, and the capacitance change directions of the two are opposite.

[0073] When subjected to a relatively small load, the inertial acceleration sensor of this embodiment can be used as an open-loop device for open-loop detection. When subjected to a relatively small load in the X direction, the second X-direction differential detection capacitor 21 and the first X-direction differential detection capacitor 22 form a group of X-direction differential detection capacitor pairs, the second X-direction differential detection capacitor 23 and the first X-direction differential detection capacitor 24 form a group of X-direction differential detection capacitor pairs, the second X-direction differential detection capacitor 25 and the first X-direction differential detection capacitor 26 form a group of X-direction differential detection capacitor pairs, and the second X-direction differential detection capacitor 27 and the first X-direction differential detection capacitor 28 form a group of X-direction differential detection capacitor pairs, and acceleration detection in the X direction is performed in a differential manner. This structure also adopts The variable area detection method can increase the linearity of the device; when subjected to a smaller load in the Y direction, the first Y-direction differential detection capacitor 37 and the second Y-direction differential detection capacitor 38 constitute a group of Y-direction differential detection capacitor pairs, the first Y-direction differential detection capacitor 39 and the second Y-direction differential detection capacitor 40 constitute a group of Y-direction differential detection capacitor pairs, and the first Y-direction differential detection capacitor 41 and the second Y-direction differential detection capacitor 42 constitute a group of Y-direction differential detection capacitor pairs, and acceleration detection in the Y direction is performed in a differential manner. This structure also adopts a variable area detection method, which can increase the linearity of the device.

[0074] When subjected to a large load, the inertial acceleration sensor of this embodiment can be used as a closed-loop device for closed-loop detection. When subjected to a large load in the X direction, the first X-direction differential detection capacitor 22, the first X-direction differential detection capacitor 24, the second X-direction differential detection capacitor 25, and the second X-direction differential detection capacitor 27 in the inner region of the mass frame 6 constitute an X-direction drive feedback capacitor, which provides an X-direction electrostatic force to the device to balance the movement of the device. The second X-direction differential detection capacitor 21 and the first X-direction differential detection capacitor 26 in the outer region of the mass frame 6 constitute a group of X-direction differential detection capacitor pairs, and the second X-direction differential detection capacitor 23 and the first X-direction differential detection capacitor 28 constitute a group of X-direction differential detection capacitor pairs, which perform acceleration detection in the X direction in a differential manner. This structure also uses a variable area The detection method can increase the linearity of the device; or the second X-direction differential detection capacitor 21, the second X-direction differential detection capacitor 23, the first X-direction differential detection capacitor 26, and the first X-direction differential detection capacitor 28 in the outer region of the mass frame 6 constitute an X-direction drive feedback capacitor, the first X-direction differential detection capacitor 22 and the second X-direction differential detection capacitor 25 in the inner region of the mass frame 6 constitute a group of X-direction differential detection capacitor pairs, the first X-direction differential detection capacitor 24 and the first X-direction differential detection capacitor 26 constitute a group of X-direction differential detection capacitor pairs, and the acceleration detection in the X direction is performed in a differential manner. The structure also adopts a variable area detection method, which can increase the linearity of the device.

[0075] When subjected to a large load in the Y direction, the second Y-direction differential detection capacitor 38, the first Y-direction differential detection capacitor 39, the second Y-direction differential detection capacitor 40 and the first Y-direction differential detection capacitor 41 in the inner region of the mass frame 6 constitute a Y-direction drive feedback capacitor, which provides an electrostatic force in the Y direction to balance the movement of the device, and the first Y-direction differential detection capacitor 37 and the second Y-direction differential detection capacitor 42 in the outer region of the mass frame 6 constitute a group of Y-direction differential detection capacitor pairs, which perform acceleration detection in the Y direction in a differential manner. This structure also adopts a variable area detection method, which can increase the linearity of the device; or The first Y-direction differential detection capacitor 37 and the second Y-direction differential detection capacitor 42 in the outer region of the mass frame 6 constitute a Y-direction driving feedback capacitor, which provides an electrostatic force in the Y direction to balance the movement of the device. The second Y-direction differential detection capacitor 38 and the first Y-direction differential detection capacitor 39 in the inner region of the mass frame 6 constitute a group of Y-direction differential detection capacitor pairs, and the second Y-direction differential detection capacitor 40 and the first Y-direction differential detection capacitor 41 constitute a group of Y-direction differential detection capacitor pairs, which perform acceleration detection in the Y direction in a differential manner. The structure also adopts a variable area detection method, which can increase the linearity of the device.

[0076] The detection structure of each direction of the inertial acceleration sensor of this embodiment is compact and independent, easy to detect, not easily disturbed, and has higher detection accuracy.

[0077] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A multi-range dual-detection inertial acceleration sensor, comprising a substrate, a device layer and an upper cover plate, characterized in that: The device layer comprises: Quality frame; A detection unit, used for performing open-loop and / or closed-loop detection of acceleration; The driving feedback capacitor is used to provide an electrostatic force to balance the movement of the mass frame when the detection unit performs closed-loop detection.

2. The inertial acceleration sensor according to claim 1, wherein: The quality frame includes a first frame and a second frame, and the first frame and the second frame are both two and are arranged opposite to each other; X-direction differential detection capacitors are respectively provided on both sides of each of the first frames for detecting the X direction; Y-direction differential detection capacitors are respectively provided on both sides of each of the second frames for detecting the Y direction.

3. The inertial acceleration sensor according to claim 2, wherein: The inner area surrounded by the mass frame is further provided with a partition beam parallel to the first frame, and the two sides of the partition beam are respectively provided with the X-direction differential detection capacitor, or A partition beam parallel to the second frame is provided, and the Y-direction differential detection capacitors are respectively provided on both sides of the partition beam.

4. The inertial acceleration sensor according to claim 2 or 3, characterized in that: When the detection unit is open-loop detection in the X direction, the detection unit is open-loop or closed-loop detection in the Y direction; When the detection unit performs closed-loop detection in the X direction, the detection unit performs open-loop or closed-loop detection in the Y direction.

5. The inertial acceleration sensor according to claim 4, characterized in that: When the detection unit is a closed-loop detection in the X direction, the X-direction differential detection capacitor in the inner or outer area of ​​the mass frame constitutes the detection unit, and the X-direction differential detection capacitor in another area constitutes the drive feedback unit, or When the detection unit performs closed-loop detection in the Y direction, the Y-direction differential detection capacitor in the inner or outer area of ​​the mass frame constitutes the detection unit, and the Y-direction differential detection capacitor in another area constitutes the drive feedback unit.

6. The inertial acceleration sensor according to claim 5, characterized in that: The capacitance change directions of the X-direction differential detection capacitors on both sides of the first frame are opposite, or the capacitance change directions of the X-direction differential detection capacitors on the same side of the first frame are opposite; the two X-direction differential detection capacitors with opposite capacitance change directions constitute a group of X-direction differential detection capacitor pairs, and the detection unit includes at least one group of X-direction differential detection capacitor pairs; The capacitance change directions of the Y-direction differential detection capacitors on both sides of the second frame are opposite, or the capacitance change directions of the Y-direction differential detection capacitors on the same side of the second frame are opposite; the two Y-direction differential detection capacitors with opposite capacitance change directions constitute a group of Y-direction differential detection capacitor pairs, and the detection unit includes at least one group of Y-direction differential detection capacitor pairs.

7. The inertial acceleration sensor according to claim 1, wherein: The device layer further includes a Z-direction detection structure, which is a parallel plate capacitor structure including a first plate and a second plate.

8. The inertial acceleration sensor according to claim 7, wherein: The first electrode plate is the device layer, and the second electrode plate is the upper cover plate.

9. The inertial acceleration sensor according to claim 1, wherein: The mass frame is connected to anchor points on the substrate via a plurality of spring beams.

10. The inertial acceleration sensor according to claim 9, characterized in that: The arrangement direction of the spring beam forms a certain angle with both the X direction and the Y direction, or the spring beam includes an X-direction spring beam arranged along the X direction and a Y-direction spring beam arranged along the Y direction.

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