Three-axis acceleration sensor and electronic equipment

Abstract

The utility model discloses a three-axis acceleration sensor and electronic equipment, the three-axis acceleration sensor comprises a movable mass block, a support beam, a fixed mass block and a main connecting beam, the movable mass block comprises a first part and a second part, the first part is provided with a hollow groove, and the second part, the fixed mass block and the support beam are all located in the hollow groove. The axial direction of the supporting beam is arranged in the third direction, the axial direction of the main connecting beam is arranged in the third direction, the main connecting beam is provided with a first end and a second end, the first end is used for being connected with the first part, the second end is used for being connected with the second part, and the middle of the main connecting beam is used for being connected with the supporting beam. The first part and the second part form a lever structure through the main connecting beam. According to the three-axis acceleration sensor disclosed by the invention, the movable mass block is symmetrically arranged relative to the axis of the supporting beam, so that the condition that the variable quantity of the third detection capacitor is not equal when the acceleration in the third direction is detected is avoided, and the precision and the reliability of the three-axis acceleration sensor are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of micro-electromechanical systems, in particular to a three-axis acceleration sensor and electronic equipment. Background Art

[0002] A triaxial accelerometer is a MEMS sensor that measures the acceleration of an object on three orthogonal axes (usually X, Y, and Z). Triaxial accelerometers typically use a system of micro-masses and springs to detect changes in the acceleration of an object in different directions. When an object's acceleration changes, the tiny mass is acted upon by the spring force, causing a tiny displacement. The sensor measures and converts these displacements into electrical signals, which are then converted into numerical form by an internal data processor.

[0003] In order to reduce the size of the three-axis acceleration sensor, some three-axis acceleration sensors use a structure in which three detection axes share a sensitive mass block. Although this reduces the size of the three-axis acceleration sensor, it increases interference between the detection axes and reduces the reliability of the three-axis acceleration sensor. Utility Model Content

[0004] The embodiments of the utility model provide a three-axis acceleration sensor and an electronic device to reduce interference between detection axes and improve the reliability of the three-axis acceleration sensor.

[0005] In order to solve the above technical problems, the embodiments of the present utility model disclose the following technical solutions:

[0006] In one aspect, a three-axis acceleration sensor is provided, having a first direction, a second direction and a third direction, wherein the first direction, the second direction and the third direction intersect and are perpendicular to each other, and the three-axis acceleration sensor comprises:

[0007] A movable mass block, the movable mass block comprising a first portion and a second portion, the first portion having a hollow groove, the second portion being located in the hollow groove;

[0008] A support beam, wherein the axial direction of the support beam is arranged along the third direction, the support beam is located in the hollow groove, and the surface of the support beam has an anchoring structure, and the anchoring structure is used to connect with the substrate;

[0009] A fixed mass block, wherein the fixed mass block is located in the hollow groove;

[0010] A main connecting beam, wherein the axial direction of the main connecting beam is arranged along the third direction, the main connecting beam has a first end and a second end, the first end is used to connect with the first part, the second end is used to connect with the second part, the middle part of the main connecting beam is used to connect with the support beam, and the first part and the second part form a lever structure through the main connecting beam.

[0011] In addition to or instead of one or more of the features disclosed above, the first part and the second part together with the fixed electrode located in the substrate constitute a first detection capacitor for detecting acceleration in the first direction, and the fixed mass block and the second part together constitute a second detection capacitor for detecting acceleration in the second direction and a third detection capacitor for detecting acceleration in the third direction.

[0012] In addition to or instead of one or more features disclosed above, a first auxiliary beam is connected to the first end, a second auxiliary beam is connected to the second end, a third auxiliary beam is connected to the middle part of the main connecting beam, the axial directions of the first auxiliary beam, the second auxiliary beam and the third auxiliary beam are all arranged along the second direction, the first part is connected to the first end through the first auxiliary beam, the second part is connected to the second end through the second auxiliary beam, and the support beam is connected to the middle part of the main connecting beam through the third auxiliary beam.

[0013] In addition to one or more features disclosed above, or as an alternative, in the third direction, the end surface of the first end protrudes from the side surface of the first auxiliary beam to form a first stop structure, and / or, in the third direction, the end surface of the second end protrudes from the side surface of the second auxiliary beam to form a second stop structure.

[0014] In addition to or as an alternative to one or more features disclosed above, in the third direction, a distance between the first auxiliary beam and the third auxiliary beam and a distance between the second auxiliary beam and the third auxiliary beam are the same or different.

[0015] In addition to one or more of the features disclosed above, or as an alternative, the support beam includes a first beam and a second beam, the axial direction of the first beam and the axial direction of the second beam are both arranged along the third direction, the first beam and the second beam are symmetrically arranged about the structural center of the first part, and there is a gap between the first beam and the second beam, the second part has a third beam, the axial direction of the third beam is arranged along the second direction and passes through the gap, and together with the first beam and the second beam, divides the hollow groove into a first zone, a second zone, a third zone and a fourth zone.

[0016] In addition to one or more of the features disclosed above, or as an alternative, the main connecting beams include four, and the four main connecting beams are symmetrically arranged about the axis of the first beam and symmetrically arranged about the axis of the third beam. In the second direction, two third auxiliary beams located on the same side of the third beam are simultaneously connected to the first beam or simultaneously connected to the second beam.

[0017] In addition to or as an alternative to one or more of the features disclosed above, the first detection capacitor formed by the first portion and the first detection capacitor formed by the second portion located on the same side of the third beam together form a set of differential capacitors.

[0018] In addition to one or more features disclosed above, or as an alternative, in the first zone, the second zone, the third zone and the fourth zone, the second part is provided with a first movable electrode and a second movable electrode, the first movable electrode is used to slide back and forth along the second direction, and the second movable electrode is used to slide back and forth along the third direction.

[0019] In addition to or as an alternative to one or more of the features disclosed above, the fixed mass comprises a first fixed electrode and a second fixed electrode, and at least one fixed mass is disposed in each zone;

[0020] In each region, the first fixed electrode and the first movable electrode constitute the second detection capacitor, and the second fixed electrode and the second movable electrode constitute the third detection capacitor.

[0021] In addition to or as an alternative to one or more features disclosed above, in the third direction, the first area and the second area are located on one side of the third beam, and the third area and the fourth area are located on the other side of the third beam;

[0022] The second detection capacitor located in the first area and the second detection capacitor located in the second area together constitute a group of differential capacitors, and the second detection capacitor located in the third area and the second detection capacitor located in the fourth area together constitute a group of differential capacitors;

[0023] The third detection capacitor located in the first area and the third detection capacitor located in the third area together constitute a group of differential capacitors, and the third detection capacitor located in the second area and the third detection capacitor located in the fourth area together constitute a group of differential capacitors.

[0024] In addition to or as an alternative to one or more features disclosed above, the first movable electrode, the second movable electrode, the first fixed electrode, and the second fixed electrode are all comb-tooth electrodes.

[0025] Additionally or alternatively to one or more features disclosed above, the mass of the first portion is greater than the mass of the second portion.

[0026] On the other hand, an electronic device is provided, comprising any of the above-mentioned three-axis acceleration sensors.

[0027] One of the above technical solutions has the following advantages or beneficial effects: in the three-axis acceleration sensor disclosed in the present application, the movable mass block includes a first part and a second part, the first part has a hollow groove, the second part is located in the hollow groove, the first part, the second part and the fixed electrode located in the substrate together constitute a first detection capacitor for detecting the acceleration in the first direction, and the fixed mass block and the second part together constitute a second detection capacitor for detecting the acceleration in the second direction and a third detection capacitor for detecting the acceleration in the third direction. Such an arrangement reduces the size of the three-axis acceleration sensor. At the same time, in the three-axis acceleration sensor disclosed in the present application, the movable mass block is symmetrically arranged about the axis of the support beam, which avoids the situation where the change amount of the third detection capacitor is unequal when detecting the acceleration in the third direction, thereby improving the accuracy and reliability of the three-axis acceleration sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The technical solutions and other beneficial effects of the present invention will be made apparent by describing in detail the specific embodiments of the present invention in conjunction with the accompanying drawings.

[0029] Figure 1 It is a structural schematic diagram of a three-axis acceleration sensor;

[0030] Figure 2 The structure of a three-axis acceleration sensor provided in accordance with an embodiment of the present application is shown in FIG. Figure 1 ;

[0031] Figure 3 The structure of a three-axis acceleration sensor provided in accordance with an embodiment of the present application is shown in FIG. Figure 2 ;

[0032] Description of reference numerals:

[0033] 10. movable mass block; 101. first part; 102. second part; 103. hollow groove;

[0034] 20. Support beam; 201. First beam; 202. Second beam; 204. Anchor structure;

[0035] 203. The Third Beam

[0036] 30. Fixed mass block;

[0037] 40. Main connecting beam; 401. First end; 402. Second end; 403. First auxiliary beam; 404. Second auxiliary beam; 405. Third auxiliary beam; 406. First stop structure; 407. Second stop structure. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and beneficial effects of the utility model clearer, the utility model is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. It should be understood that the specific implementation methods described in this specification are only for explaining the utility model, and are not intended to limit the utility model.

[0039] In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present utility model 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 utility model. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present utility model, the meaning of "multiple" refers to two or more, unless otherwise clearly and specifically defined.

[0040] In the description of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0041] In the present utility model, unless otherwise clearly stipulated and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0042] A triaxial accelerometer is a MEMS sensor that measures the acceleration of an object on three orthogonal axes (usually X, Y, and Z). Triaxial accelerometers typically use a system of miniature masses and springs to detect changes in acceleration of an object in different directions. When an object experiences a change in acceleration, the tiny mass is acted upon by the spring force, causing a tiny displacement. The sensor measures and converts these displacements into electrical signals, which are then converted into numerical form by an internal data processor.

[0043] In order to reduce the size of the three-axis acceleration sensor, some three-axis acceleration sensors use a structure in which three detection axes share a sensitive mass block. Although this reduces the size of the three-axis acceleration sensor, it increases the interference between the detection axes and reduces the reliability of the three-axis acceleration sensor. Specifically, the structure of some three-axis acceleration sensors is as follows: Figure 1 As shown, the three-axis acceleration sensor has a first direction, a second direction and a third direction, and the first direction, the second direction and the third direction intersect and are perpendicular to each other. The three-axis acceleration sensor includes: a movable mass block 10, a support beam 20 and a fixed mass block 30. The movable mass block 10 includes a first part 101 and a second part 102. The first part 101 has a hollow groove 103, and the support beam 20, the fixed mass block 30 and the second part 102 are all located in the hollow groove 103. The first part 101 and the second part 102 are connected by an elastic beam, the support beam 20 and the second part 102 are connected by an elastic beam, the second part 102 has a movable electrode, and the movable electrode and the fixed mass block 30 are arranged on both sides of the support beam 20. In the embodiment of the present application, the first direction is perpendicular to the plane where the movable mass block 10 is located, the second direction and the third direction are parallel to the plane where the movable mass block 10 is located, and the first part 101 and the fixed electrode located in the substrate constitute a first detection capacitor for detecting the acceleration in the first direction. The second portion 102 and the fixed mass 30 together form a second detection capacitor for detecting acceleration in a second direction and a third detection capacitor for detecting acceleration in a third direction.

[0044] The axial direction of the support beam 20 is arranged along the third direction, and the first portion 101 is arranged eccentrically with respect to the axis of the support beam 20. Figure 1 The mass of the first portion 101 located on the right side of the support beam 20 is greater than the mass of the portion located on the left side of the support beam 20. When detecting the acceleration in the first direction, the first portion 101 twists along the first direction, and the portion located on the right side of the support beam 20 and the portion located on the left side of the support beam 20 move in opposite directions.

[0045] When the above-mentioned three-axis acceleration sensor detects the acceleration in the third direction, the first part 101 and the second part 102 slide back and forth in the third direction. Since the first part 101 is eccentrically arranged with respect to the axis of the support beam 20, the mass of the part located on the left side of the support beam 20 is smaller than the mass of the part located on the right side of the support beam 20, resulting in the movement displacement of the movable electrode located on the left side of the support beam 20 being greater than the movement displacement of the movable electrode located on the right side of the support beam 20, making the capacitance change of the third detection capacitor located on the left side of the support beam 20 inconsistent with the capacitance change of the third detection capacitor located on the right side of the support beam 20, which affects the detection accuracy and reliability of the three-axis acceleration sensor.

[0046] In order to reduce the interference between the detection axes and improve the reliability of the three-axis acceleration sensor, refer to Figure 2 , the embodiment of the present application discloses a three-axis acceleration sensor, which also has a first direction, a second direction and a third direction, and the first direction, the second direction and the third direction intersect each other and are perpendicular. The three-axis acceleration sensor disclosed in the present application includes: a movable mass block 10, a support beam 20, a fixed mass block 30 and a main connecting beam 40. The movable mass block 10 includes a first part 101 and a second part 102. The first part 101 has a hollow groove 103, and the second part 102, the support beam 20 and the fixed mass block 30 are all located in the hollow groove 103. The axial direction of the support beam 20 is arranged along the third direction, and the surface of the support beam 20 has an anchoring structure 204, and the anchoring structure 204 is used to connect with the substrate. The axial direction of the main connecting beam 40 is arranged along the third direction, and the main connecting beam 40 has a first end 401 and a second end 402, the first end 401 is used to connect with the first part 101, the second end 402 is used to connect with the second part 102, and the middle part of the main connecting beam 40 is used to connect with the support beam 20. The first part 101 and the second part 102 form a lever structure through the main connecting beam 40. The first part 101 and the second part 102 and the fixed electrode located in the substrate form a first detection capacitor for detecting acceleration in a first direction, and the fixed mass block 30 and the second part 102 together form a second detection capacitor for detecting acceleration in a second direction and a third detection capacitor for detecting acceleration in a third direction.

[0047] In some embodiments, a first auxiliary beam 403 is connected to the first end 401, a second auxiliary beam 404 is connected to the second end 402, and a third auxiliary beam 405 is connected to the middle of the main connecting beam 40. Specifically, the axial direction of the first auxiliary beam 403, the axial direction of the second auxiliary beam 404, and the axial direction of the third auxiliary beam 405 are all arranged along the second direction. The first part 101 is connected to the first end 401 through the first auxiliary beam 403, the second part 102 is connected to the second end 402 through the second auxiliary beam 404, and the support beam 20 is connected to the middle of the main connecting beam 40 through the third auxiliary beam 405. Moreover, the mass of the first part 101 is greater than the mass of the second part 102. When detecting the acceleration in the first direction, the third auxiliary beam 405 is twisted. Because the first auxiliary beam 403, the second auxiliary beam 404 and the third auxiliary beam 405 are all connected to the main connecting beam 40, and the first auxiliary beam 403 and the second auxiliary beam 404 are respectively located at the two ends of the main connecting beam 40, and the third auxiliary beam 405 is connected to the middle part of the main connecting beam 40, when the third auxiliary beam 405 is twisted, the movement directions of the first auxiliary beam 403 and the second auxiliary beam 404 in the first direction are opposite, and the movement directions of the first part 101 connected to the first auxiliary beam 403 and the second part 102 connected to the second auxiliary beam 404 are also opposite, the capacitance value of the first detection capacitor formed by the first part 101 changes, and the capacitance value of the first detection capacitor formed by the second part 102 also changes.

[0048] Thus, in the embodiment disclosed in the present application, the first part 101 and the second part 102 form a lever structure through the main connecting beam 40, which can detect the acceleration in the first direction during detection. Figure 1 The three-axis acceleration sensor shown in the embodiment disclosed in the present application has a movable mass block 10 symmetrically arranged about the axis of the support beam 20, which avoids unequal changes in the third detection capacitor when detecting acceleration in the third direction, thereby affecting the detection accuracy and reliability of the three-axis acceleration sensor.

[0049] Furthermore, in some embodiments, in the third direction, the end surface of the first end 401 protrudes from the side of the first auxiliary beam 403, forming a first stop structure 406, and the end surface of the second end 402 protrudes from the side of the second auxiliary beam 404, forming a second stop structure 407. When detecting the acceleration in the first direction, the movement change of the main connecting beam 40 is the largest. Providing stop structures at the first end 401 and the second end 402 can prevent the first part 101 and the second part 102 from sticking to each other, reduce the probability of product failure, and further improve product reliability.

[0050] Further, in some embodiments, in the third direction, the distance between the first auxiliary beam 403 and the third auxiliary beam 405 is the same as the distance between the second auxiliary beam 404 and the third auxiliary beam 405 (see Figure 2In some embodiments, the distance between the first auxiliary beam 403 and the third auxiliary beam 405 is different from the distance between the second auxiliary beam 404 and the third auxiliary beam 405 (see Figure 3 ). When the distance between the first auxiliary beam 403 and the third auxiliary beam 405 is the same as the distance between the second auxiliary beam 404 and the third auxiliary beam 405, the change in the first detection capacitance formed by the first part 101 is the same as the change in the first detection capacitance formed by the second part 102. When the distance between the first auxiliary beam 403 and the third auxiliary beam 405 is different from the distance between the second auxiliary beam 404 and the third auxiliary beam 405, for example, when the distance between the first auxiliary beam 403 and the third auxiliary beam 405 is smaller than the distance between the second auxiliary beam 404 and the third auxiliary beam 405, in the first direction, the change in the movement of the first part 101 is smaller than the change in the movement of the second part 102, and the change in the first detection capacitance formed by the first part 101 is smaller than the change in the first detection capacitance formed by the second part 102. In practical applications, the sensitivity of the three-axis accelerometer to measure the acceleration in the first direction can be adjusted by adjusting the distance between the first auxiliary beam 403 and the third auxiliary beam 405 and the distance between the second auxiliary beam 404 and the third auxiliary beam 405.

[0051] In some embodiments, the support beam 20 includes a first beam 201 and a second beam 202, the axial direction of the first beam 201 and the axial direction of the second beam 202 are both arranged along the third direction, the first beam 201 and the second beam 202 are arranged symmetrically about the structural center of the first part 101, and there is a gap between the first beam 201 and the second beam 202. The second part 102 has a third beam 203, the axial direction of the third beam 203 is arranged along the second direction, and passes through the gap, and together with the first beam 201 and the second beam 202, the hollow groove 103 is divided into a first area, a second area, a third area and a fourth area. Further, in some embodiments, in the first area, the second area, the third area and the fourth area, the second part 102 is provided with a first movable electrode and a second movable electrode, the first movable electrode is used to slide back and forth along the second direction, and the second movable electrode is used to slide back and forth along the third direction, the fixed mass block 30 includes a first fixed electrode and a second fixed electrode, and at least one fixed mass block 30 is provided in each area. In each region, the first fixed electrode and the first movable electrode constitute a second detection capacitor, and the second fixed electrode and the second movable electrode constitute a third detection capacitor.

[0052] In some embodiments, in the third direction, the first area and the second area are located on one side of the third beam 203, and the third area and the fourth area are located on the other side of the third beam 203. The second detection capacitor located in the first area and the second detection capacitor located in the second area together constitute a group of differential capacitors, and the second detection capacitor located in the third area and the second detection capacitor located in the fourth area together constitute a group of differential capacitors. The third detection capacitor located in the first area and the third detection capacitor located in the third area together constitute a group of differential capacitors, and the third detection capacitor located in the second area and the third detection capacitor located in the fourth area together constitute a group of differential capacitors.

[0053] In some embodiments, the first movable electrode, the second movable electrode, the first fixed electrode, and the second fixed electrode are all comb-teeth electrodes.

[0054] It should be noted that in the embodiment disclosed in the present application, the movable electrode is disposed on the second part 102, and the movable electrode is a comb-tooth electrode, which further reduces the mass of the second part 102. Such a configuration increases the mass difference between the second part 102 and the first part 101, and further improves the sensitivity of the three-axis acceleration sensor.

[0055] In some embodiments, the main connecting beams 40 include four main connecting beams 40, which are symmetrically arranged about the axis of the first beam 201 and the axis of the third beam 203. In the second direction, two third auxiliary beams 405 located on the same side of the third beam 203 are simultaneously connected to the first beam 201 or the second beam 202. When detecting the acceleration in the first direction, the first part 101 and the second part 102 located on the same side of the third beam 203 move in opposite directions, and the first detection capacitor formed by the first part 101 and the first detection capacitor formed by the second part 102 located on the same side of the third beam 203 together constitute a set of differential capacitors.

[0056] An embodiment of the present application also discloses an electronic device, comprising any of the above-mentioned three-axis acceleration sensors.

[0057] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0058] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A three-axis acceleration sensor, characterized in that: The three-axis acceleration sensor has a first direction, a second direction and a third direction, wherein the first direction, the second direction and the third direction intersect and are perpendicular to each other, and the three-axis acceleration sensor comprises: A movable mass block (10), the movable mass block (10) comprising a first part (101) and a second part (102), the first part (101) having a hollow groove (103), and the second part (102) being located in the hollow groove (103); A support beam (20), wherein the axial direction of the support beam (20) is arranged along the third direction, the support beam (20) is located in the hollow groove (103), and the support beam (20) has an anchoring structure (204), and the anchoring structure (204) is used to be connected to a substrate; A fixed mass block (30), the fixed mass block (30) being located in the hollow groove (103); A main connecting beam (40), wherein the axial direction of the main connecting beam (40) is arranged along the third direction, the main connecting beam (40) has a first end (401) and a second end (402), the first end (401) is used to connect with the first part (101), the second end (402) is used to connect with the second part (102), the middle part of the main connecting beam (40) is used to connect with the support beam (20), and the first part (101) and the second part (102) form a lever structure through the main connecting beam (40).

2. The three-axis acceleration sensor according to claim 1, characterized in that: The first part (101) and the second part (102) together with the fixed electrode located in the substrate form a first detection capacitor for detecting acceleration in the first direction, and the fixed mass block (30) and the second part (102) together form a second detection capacitor for detecting acceleration in the second direction and a third detection capacitor for detecting acceleration in the third direction.

3. The three-axis acceleration sensor according to claim 2, characterized in that: The first end (401) is connected to a first auxiliary beam (403), the second end (402) is connected to a second auxiliary beam (404), the middle part of the main connecting beam (40) is connected to a third auxiliary beam (405), the axial direction of the first auxiliary beam (403), the axial direction of the second auxiliary beam (404) and the axial direction of the third auxiliary beam (405) are all arranged along the second direction, the first part (101) is connected to the first end (401) through the first auxiliary beam (403), the second part (102) is connected to the second end (402) through the second auxiliary beam (404), and the support beam (20) is connected to the middle part of the main connecting beam (40) through the third auxiliary beam (405).

4. The three-axis acceleration sensor according to claim 3, characterized in that: In the third direction, the end surface of the first end (401) protrudes from the side surface of the first auxiliary beam (403), forming a first stop structure (406); And / or, in the third direction, the end surface of the second end (402) protrudes from the side surface of the second auxiliary beam (404), forming a second stop structure (407).

5. The three-axis acceleration sensor according to claim 3, characterized in that: In the third direction, the distance between the first auxiliary beam (403) and the third auxiliary beam (405) and the distance between the second auxiliary beam (404) and the third auxiliary beam (405) are the same or different.

6. The three-axis acceleration sensor according to claim 3, characterized in that: The support beam (20) comprises a first beam (201) and a second beam (202), the axial direction of the first beam (201) and the axial direction of the second beam (202) are both arranged along the third direction, the first beam (201) and the second beam (202) are symmetrically arranged about the structural center of the first part (101), and there is a gap between the first beam (201) and the second beam (202), the second part (102) has a third beam (203), the third beam (203) passes through the gap and is axially arranged along the second direction, and the third beam (203) and the first beam (201) and the second beam (202) together divide the hollow groove (103) into a first area, a second area, a third area and a fourth area.

7. The three-axis acceleration sensor according to claim 6, characterized in that: The main connecting beams (40) include four main connecting beams (40), which are symmetrically arranged about the axis of the first beam (201) and the axis of the third beam (203). In the second direction, two third auxiliary beams (405) located on the same side of the third beam (203) are simultaneously connected to the first beam (201) or simultaneously connected to the second beam (202).

8. The three-axis acceleration sensor according to claim 7, characterized in that: The first detection capacitor formed by the first part (101) and the first detection capacitor formed by the second part (102) located on the same side of the third beam (203) together form a group of differential capacitors.

9. The three-axis acceleration sensor according to claim 6, characterized in that: In the first zone, the second zone, the third zone and the fourth zone, the second part (102) is provided with a first movable electrode and a second movable electrode, the first movable electrode is used for reciprocating sliding along the second direction, and the second movable electrode is used for reciprocating sliding along the third direction.

10. The three-axis acceleration sensor according to claim 9, characterized in that: The fixed mass block (30) comprises a first fixed electrode and a second fixed electrode, and at least one fixed mass block (30) is arranged in each zone; In each region, the first fixed electrode and the first movable electrode constitute the second detection capacitor, and the second fixed electrode and the second movable electrode constitute the third detection capacitor.

11. The three-axis acceleration sensor according to claim 10, characterized in that: In the third direction, the first area and the second area are located on one side of the third beam (203), and the third area and the fourth area are located on the other side of the third beam (203); The second detection capacitor located in the first area and the second detection capacitor located in the second area together constitute a group of differential capacitors, and the second detection capacitor located in the third area and the second detection capacitor located in the fourth area together constitute a group of differential capacitors; The third detection capacitor located in the first area and the third detection capacitor located in the third area together constitute a group of differential capacitors, and the third detection capacitor located in the second area and the third detection capacitor located in the fourth area together constitute a group of differential capacitors.

12. The three-axis acceleration sensor according to claim 10, characterized in that: The first movable electrode, the second movable electrode, the first fixed electrode, and the second fixed electrode are all comb-teeth electrodes.

13. The three-axis acceleration sensor according to claim 1, characterized in that: The mass of the first portion (101) is greater than the mass of the second portion (102).

14. An electronic device, characterized in that: It comprises a three-axis acceleration sensor as described in any one of claims 1-13.

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