Accelerometer with main and auxiliary beam structure

Abstract

The utility model provides an accelerometer with a main and auxiliary beam structure. The accelerometer comprises a substrate, a wiring layer arranged on the substrate, and a structural layer anchored above the wiring layer. The structural layer comprises a movable mass block corresponding to the wiring layer, a torsional pendulum elastic beam connected with the movable mass block, an anchor point for connecting the wiring layer with the center of the torsional pendulum elastic beam, and a reinforcing beam connected to the torsional pendulum elastic beam; wherein the movable mass blocks are asymmetrically distributed on the two sides of the torsional pendulum elastic beam, so that the technical scheme of the accelerometer which can ensure that the accelerometer has better output stability and smaller cross axis sensitivity under the condition that the accelerometer has higher sensitivity is realized.

Description

Technical Field

[0001] The utility model relates to the technical field of accelerometers, in particular to an accelerometer with a main beam and a secondary beam structure. Background Art

[0002] Capacitive accelerometers are devices that use external acceleration to change the displacement of sensitive mass, which is then converted into a change in capacitance for measurement. Accelerometers can detect acceleration from three axes. The Z-axis structure design is generally a torsion pendulum capacitive accelerometer, in which the sensitive mass blocks are asymmetrically distributed on both sides of the torsion pendulum elastic beam to form an eccentric torque. When there is external acceleration input, the sensitive mass block swings around the beam and forms a differential capacitance with the detection capacitor plate below, and the magnitude of the acceleration is obtained according to the magnitude of the capacitance change. The current common Z-axis accelerometer structure is a single mass block seesaw type, and the entire movable mass block is connected to a fixed anchor point through a simple torsion pendulum elastic beam. At the same time, in order to ensure the stability of the accelerometer output and reduce the cross-axis sensitivity, the length and width of the single torsion pendulum elastic beam cannot be made very small. This size limitation has a great restriction on the sensitivity of the accelerometer. On the other hand, if the sensitivity of the accelerometer is very large, the overall dynamic output stability of the accelerometer is poor, and there is a large cross-axis sensitivity.

[0003] The common seesaw-type torsion pendulum accelerometer beam structure is simple in design, and the accelerometer is large in size. The movable mass block is only connected to the anchor point through a simple torsion pendulum elastic beam. Due to the large size of the accelerometer and the simple design of the torsion pendulum elastic beam, in order to make the accelerometer have a greater sensitivity, the dynamic characteristics of the accelerometer are poor and the cross-axis sensitivity is large. On the other hand, in order to ensure the stability of the dynamic performance of the accelerometer and reduce the cross-axis sensitivity, the accelerometer cannot obtain a greater sensitivity. The current conventional design scheme cannot ensure that the accelerometer has good output stability and a smaller cross-axis sensitivity while ensuring that the accelerometer has a greater sensitivity.

[0004] Therefore, it is necessary to provide an accelerometer technical solution that can ensure that the accelerometer has better output stability and smaller cross-axis sensitivity while ensuring that the accelerometer has greater sensitivity. Utility Model Content

[0005] In order to solve the above technical problems, the utility model provides an accelerometer with a main beam and a secondary beam structure.

[0006] The utility model provides an accelerometer with a main and auxiliary beam structure, comprising: a substrate, a wiring layer arranged on the substrate, and a structural layer anchored above the wiring layer;

[0007] The structural layer comprises: a movable mass block corresponding to the routing layer, a yaw elastic beam connected to the movable mass block, an anchor point connecting the routing layer and the center of the yaw elastic beam, and a reinforcing beam connected to the yaw elastic beam;

[0008] Wherein, the movable mass blocks are asymmetrically distributed on both sides of the torsion spring beam.

[0009] In a possible implementation manner, the reinforcement beams are arranged in pairs on both sides of the torsion spring beam.

[0010] In a possible implementation manner, the reinforcing beam is symmetrically arranged along the torsion spring beam.

[0011] In a possible implementation manner, the reinforcement beam is a rectangular structure composed of straight beams.

[0012] In a possible implementation, the reinforcing beam is composed of a first rectangular beam and a second rectangular beam having two different sizes nested together.

[0013] In a possible implementation manner, the first rectangular beam and the second rectangular beam are connected by a plurality of straight beams.

[0014] In a possible implementation manner, the reinforcing beam is asymmetrically arranged along the torsion spring beam.

[0015] In a possible implementation manner, the reinforcing beams are equidistantly distributed above and below the anchor point on both sides of the torsion spring beam.

[0016] In a possible implementation, part or all of the reinforcing beam is designed to be widened.

[0017] The technical solution provided by the utility model has at least the following beneficial effects:

[0018] A new Z-axis torsion pendulum elastic beam structure accelerometer is proposed. By arranging a reinforcing beam on the main beam, i.e. the torsion pendulum elastic beam, the accelerometer can have a better dynamic output characteristic while ensuring a greater sensitivity. At the same time, the cross-axis sensitivity can be reduced and the overall impact resistance can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic diagram of a first top view structure of an accelerometer with a main and auxiliary beam structure provided by an embodiment of the utility model;

[0020] Figure 2 Corresponding to the embodiment of the utility model Figure 1 The cross-sectional view of the accelerometer along line AA at zero acceleration input;

[0021] Figure 3 A schematic diagram of a second top view structure of an accelerometer with a main and auxiliary beam structure provided by an embodiment of the utility model;

[0022] Figure 4 A third schematic diagram of a top view of the accelerometer with a main and auxiliary beam structure provided by an embodiment of the utility model;

[0023] Figure 5 A fourth top view structural schematic diagram of an accelerometer with a main and auxiliary beam structure provided by an embodiment of the utility model;

[0024] Figure 6 A fifth schematic diagram of a top view of an accelerometer with a main and auxiliary beam structure provided by an embodiment of the utility model;

[0025] Figure 7 A sixth schematic diagram of a top view of an accelerometer with a main and auxiliary beam structure provided by an embodiment of the utility model;

[0026] Figure 8 A seventh schematic diagram of a top view of an accelerometer with a main and auxiliary beam structure provided by an embodiment of the utility model;

[0027] Fig. 9 An eighth schematic diagram of a top view structure of an accelerometer with a main and auxiliary beam structure provided by an embodiment of the utility model;

[0028] In the accompanying drawings, 10, substrate; 20, routing layer; 21, detection capacitor plate; 30, structural layer; 31, movable mass block; 32, torsion elastic beam; 33, anchor point; 34, reinforcement beam; 341, first rectangular beam; 342, second rectangular beam; 343, widened horizontal beam; 344, widened vertical beam; 345, widened beam section; 40, insulation layer. DETAILED DESCRIPTION

[0029] In order to deepen the understanding of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. The embodiments are only used to explain the present invention and do not limit the protection scope of the present invention.

[0030] Please refer to Figures 1 to 9 The utility model provides an accelerometer with a main and auxiliary beam structure, comprising: a substrate 10, a wiring layer 20 disposed on the substrate 10, and a structural layer 30 anchored above the wiring layer 20;

[0031] The structural layer 30 includes: a movable mass block 31 corresponding to the wiring layer 20, a yaw elastic beam 32 connected to the movable mass block 31, an anchor point 33 connecting the wiring layer 20 and the center of the yaw elastic beam 32, and a reinforcing beam 34 connected to the yaw elastic beam 32;

[0032] The movable mass blocks 31 are asymmetrically distributed on both sides of the torsion spring beam 32 .

[0033] In this embodiment, the substrate 10 adopts a conventional design. The routing layer 20 includes a detection capacitor plate 21 opposite to the structural layer 30, and is also provided with a signal lead-out line. The detection capacitor plate 21 is a conventional differential capacitor structure. The structural layer 30 is the main moving part of the accelerometer. An insulating layer 40 can also be provided between the substrate 10 and the routing layer 20. The main structure of the accelerometer composed of the substrate 10, the routing layer 20, and the structural layer 30 still belongs to the conventional Z-axis accelerometer structure.

[0034] The movable mass block 31 can be understood as a sensitive mass block. The wiggling elastic beam 32 serves as the main beam, and the reinforcing beam 34 serves as the secondary beam, and the combination of the two constitutes a main and secondary beam structure. The anchor point 33 is a conventional design, which is used to anchor the routing layer 20 and the wiggling elastic beam 32 together. The capacitance sensitivity of the entire accelerometer is determined by the torsional stiffness of the main beam, i.e., the wiggling elastic beam 32. The reinforcing beam 34 is located on the wiggling elastic beam 32 and is not connected to the movable mass block 31. It can improve the dynamic output stability of the entire accelerometer chip without affecting the capacitance sensitivity of the accelerometer, and can also reduce the cross-axis sensitivity.

[0035] In a possible implementation, the reinforcing beams 34 are disposed in pairs on both sides of the torsion spring beam 32 .

[0036] In this embodiment, the reinforcing beam 34 can be designed with a single or multiple sub-beams, and the sub-beams can be independent of each other or can be designed in a coupled manner. The shape of the reinforcing beam 34 is not limited to a straight beam, and can be an arc beam or other forms. The beam widths of the torsion spring beam 32 and the reinforcing beam 34 can be equal or unequal. The widths of each section of the reinforcing beam 34 can also be equal or unequal, and a local widening design can also be performed.

[0037] In a possible implementation, the reinforcing beams 34 are symmetrically arranged along the torsion spring beams 32 .

[0038] In this embodiment, Figures 1 to 5 , Figures 7 to 9 The reinforcing beam 34 can be designed to be symmetrically arranged with respect to the torsion spring beam 32. The specific design of the reinforcing beam 34 can be selected according to the specific accelerometer solution.

[0039] In a possible implementation, the reinforcing beam 34 is a rectangular structure composed of straight beams.

[0040] In one possible implementation, Figure 4The reinforcing beam 34 is composed of a first rectangular beam 341 and a second rectangular beam 342 of two different sizes nested together.

[0041] In this embodiment, the first rectangular beam 341 and the second rectangular beam 342 are two rectangular beams of different sizes.

[0042] In one possible implementation, Figure 5 The first rectangular beam 341 and the second rectangular beam 342 are connected by a plurality of straight beams.

[0043] In this embodiment, the first rectangular beam 341 and the second rectangular beam 342 are connected to form a whole, so that the structure of the reinforcing beam 34 can be reinforced and the stability of the reinforcing beam 34 can be improved.

[0044] In one possible implementation, Figure 6 The reinforcing beam 34 is asymmetrically arranged along the torsion spring beam 32 .

[0045] In this embodiment, the reinforcing beams 34 may be staggered and asymmetrically arranged with respect to the torsion elastic beams 32 .

[0046] In one possible implementation, Figure 6 The reinforcing beams 34 are equidistantly distributed above and below the anchor point 33 on both sides of the torsion spring beam 32 .

[0047] In one possible implementation, Figures 7 to 9 , part or all of the reinforcing beam 34 is designed to be widened.

[0048] In this embodiment, the reinforcing beam 34 can be widened at a local position. Figure 7 The cross beam of the reinforcement beam 34 is widened to be a widened cross beam 343, or it can be Figure 8 The vertical beam of the reinforcement beam 34 is widened to be designed as a widened vertical beam 344, and it can also be Fig. 9 Part of the beam section in the vertical beam of the reinforcement beam 34 is widened to form a widened beam section 345. In specific implementation, other parts can also be widened according to actual needs.

[0049] The above embodiments should not limit the present invention in any way, and any technical solutions obtained by equivalent replacement or equivalent conversion shall fall within the protection scope of the present invention.

Claims

1. An accelerometer with a main and auxiliary beam structure, characterized in that: include: A substrate, a wiring layer disposed on the substrate, and a structural layer anchored above the wiring layer; The structural layer comprises: a movable mass block corresponding to the routing layer, a yaw elastic beam connected to the movable mass block, an anchor point connecting the routing layer and the center of the yaw elastic beam, and a reinforcing beam connected to the yaw elastic beam; Wherein, the movable mass blocks are asymmetrically distributed on both sides of the torsion spring beam.

2. The accelerometer according to claim 1, characterized in that The reinforcing beams are arranged in pairs on both sides of the torsion spring beam.

3. The accelerometer according to claim 2, characterized in that The reinforcing beams are symmetrically arranged along the torsion spring beams.

4. The accelerometer according to claim 3, characterized in that The reinforcing beam is a rectangular structure composed of straight beams.

5. The accelerometer according to claim 4, characterized in that The reinforcing beam is composed of two first rectangular beams and a second rectangular beam having different sizes nested therein.

6. The accelerometer according to claim 5, characterized in that The first rectangular beam and the second rectangular beam are connected by a plurality of straight beams.

7. The accelerometer according to claim 2, characterized in that The reinforcing beam is asymmetrically arranged along the torsion spring beam.

8. The accelerometer according to claim 7, characterized in that The reinforcing beams are equidistantly distributed above and below the anchor point on both sides of the torsion spring beam.

9. The accelerometer according to any one of claims 1 to 8, characterized in that: Part or all of the reinforcing beam is designed to be widened.

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