MEMS three-axis acceleration sensor

Abstract

The utility model discloses an MEMS three-axis acceleration sensor, relates to the technical field of sensors, and can effectively reduce transverse cross interference and improve sensitivity and measurement precision. The MEMS three-axis acceleration sensor comprises silicon MEMS acceleration sensors which are respectively arranged in three directions of a three-dimensional coordinate system, the X coordinate, the Y coordinate and the Z coordinate are mutually orthogonal, and meanwhile, the silicon MEMS acceleration sensors on the coordinate axes do not interfere with one another during working; the silicon MEM acceleration sensor comprises a silicon frame and a mass block connected with the silicon frame through a sensitive beam and a supporting beam, the sensitive beam is provided with a piezoresistor, and the piezoresistor is electrically connected with an external PCB through a lead to form a Wheatstone bridge; and the support beam, the sensitive beam and the mass block form an acceleration sensor structure with an in-plane composite beam structure.

Description

Technical Field

[0001] The utility model relates to the technical field of sensors, in particular to a MEMS three-axis acceleration sensor. Background Art

[0002] Three-axis accelerometers can be used to detect and measure the acceleration, velocity, and position changes of objects. They are often used in consumer electronics such as mobile phones, tablets, game controllers, and motion tracking devices to perform functions such as automatic screen rotation, attitude control, and motion tracking. In addition, three-axis accelerometers can also play a role in aerospace, automotive industry, medical equipment, and other fields, such as aircraft attitude control, high-speed train operation monitoring, and human gravity simulation experiments.

[0003] Its principle is based on micro-electromechanical system (MEMS) technology, which uses tiny acceleration changes to cause changes in the vibration frequency of the microstructure itself for measurement. Specifically, there is a tiny mass block connected to a spring inside the sensor. When subjected to acceleration, the mass block moves in one direction, causing the spring to expand and contract, thereby changing the vibration frequency of the microstructure. By detecting this frequency change, the acceleration of the object can be calculated. Utility Model Content

[0004] The utility model aims to provide a MEMS three-axis acceleration sensor, which can effectively reduce lateral cross interference and improve sensitivity and measurement accuracy.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] A MEMS three-axis acceleration sensor, comprising: silicon MEMS acceleration sensors respectively arranged in three directions of a three-dimensional coordinate system, wherein the three coordinates X, Y, and Z are mutually orthogonal, and the silicon MEMS acceleration sensors on the coordinate axes do not interfere with each other during operation;

[0007] The silicon MEM acceleration sensor includes: a silicon frame, and a mass block connected to the silicon frame through a sensitive beam and a supporting beam, and the sensitive beam is provided with a piezoresistor, and the piezoresistor is electrically connected to an external PCB board through a lead to form a Wheatstone bridge; the supporting beam, the sensitive beam and the mass block form an in-plane composite beam structure acceleration sensor structure.

[0008] In practical application, the sensitive beams are arranged at two opposite end surfaces of the mass block, and the supporting beams are arranged at the other two opposite end surfaces of the mass block, and the axes of the sensitive beams and the supporting beams are both located at the center of the mass block.

[0009] The thickness of the sensitive beam is smaller than the thickness of the supporting beam, and the thickness of the supporting beam is smaller than the thickness of the mass block.

[0010] Specifically, the sensitive beam is provided with two pads, and the varistor is connected to each pad through a lead wire;

[0011] The PCB board has twelve metal pads, and every two adjacent metal pads form a group. At the same time, the two metal pads in each group are electrically connected to the pads of the varistor through wires in a one-to-one correspondence to form a Wheatstone bridge.

[0012] Further, the silicon MEM acceleration sensor on the X-axis of the three-dimensional coordinate system measures the X-axis acceleration value, the silicon MEM acceleration sensor on the Z-axis measures the Z-axis acceleration value, and the silicon MEM acceleration sensor on the Y-axis measures the Y-axis acceleration value.

[0013] Compared with the prior art, the MEMS three-axis acceleration sensor described in the utility model has the following advantages:

[0014] In the MEMS three-axis acceleration sensor provided by the utility model, due to the adoption of an in-plane acceleration sensor structure, the lateral cross interference of a single sensor can be effectively reduced, and each sensor has a high natural frequency and measurement sensitivity, so the measurement accuracy of the three-axis acceleration sensor can be guaranteed. When the three sensors are working, the in-plane architecture can be used to avoid mutual interference between the sensors, and the accuracy of the measurement to be measured can be effectively improved, so that the natural frequencies in three directions are effectively guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the structure of a MEMS three-axis acceleration sensor provided in an embodiment of the utility model.

[0016] Reference numerals:

[0017] 1-sensitive beam; 2-support beam; 3-mass block; 4-varistor; 5-soldering pad. Implementation

[0018] For ease of understanding, the embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.

[0019] The utility model provides a MEMS three-axis acceleration sensor, such as Figure 1 As shown, it includes: silicon MEMS acceleration sensors respectively arranged in three directions of a three-dimensional coordinate system, and the three coordinates of X, Y, and Z are mutually orthogonal, and the silicon MEM acceleration sensors on the coordinate axes will not interfere with each other when working;

[0020] The silicon MEM acceleration sensor comprises: a silicon frame, and a mass block 3 connected to the silicon frame through a sensitive beam 1 and a supporting beam 2, and the sensitive beam 1 is provided with a piezoresistor 4, and the piezoresistor 4 is electrically connected to an external PCB board through a lead to form a Wheatstone bridge; the supporting beam 2, the sensitive beam 1 and the mass block 3 form an in-plane composite beam structure acceleration sensor structure.

[0021] Compared with the prior art, the MEMS three-axis acceleration sensor described in the embodiment of the utility model has the following advantages:

[0022] In the MEMS three-axis acceleration sensor provided by the embodiment of the utility model, due to the adoption of an in-plane acceleration sensor structure, the lateral cross interference of a single sensor can be effectively reduced, and each sensor has a high natural frequency and measurement sensitivity, so the measurement accuracy of the three-axis acceleration sensor can be guaranteed. When the three sensors are working, the in-plane architecture can be used to avoid mutual interference between the sensors, and the accuracy of the measurement to be measured can be effectively improved, so that the natural frequencies in three directions are effectively guaranteed.

[0023] In actual application, two opposite end surfaces of the mass block 3 are provided with sensitive beams 1 , and two other opposite end surfaces of the mass block 3 are provided with supporting beams 2 , and the axes of the sensitive beam 1 and the supporting beam 2 are both located at the center of the mass block 3 .

[0024] The thickness of the sensitive beam 1 is smaller than the thickness of the supporting beam 2 , and the thickness of the supporting beam 2 is smaller than the thickness of the mass block 3 .

[0025] Specifically, the above-mentioned sensitive beam 1 is provided with two pads 5, and the varistor 4 is connected to each pad 5 through a lead wire;

[0026] The PCB board has twelve metal pads, and every two adjacent metal pads form a group. Meanwhile, the two metal pads in each group are electrically connected to the pads 5 of the varistor 4 in a one-to-one correspondence through wires to form a Wheatstone bridge.

[0027] Further, the silicon MEM acceleration sensor on the X-axis of the three-dimensional coordinate system measures the X-axis acceleration value, the silicon MEM acceleration sensor on the Z-axis measures the Z-axis acceleration value, and the silicon MEM acceleration sensor on the Y-axis measures the Y-axis acceleration value.

[0028] It should be noted here that MEMS is the abbreviation of Micro-Electro-Mechanical System, which is translated as micro-electromechanical system, also called micro-electromechanical system, microsystem, micro-machine, etc., and refers to high-tech devices with a size of several millimeters or even smaller. The internal structure of a micro-electromechanical system is generally in the micron or even nanometer level, and it is an independent intelligent system. The micro-electromechanical system is developed on the basis of microelectronics technology (semiconductor manufacturing technology), and is a high-tech electronic mechanical device made by integrating technologies such as lithography, corrosion, thin film, LIGA, silicon micromachining, non-silicon micromachining and precision machining. A micro-electromechanical system is a micro device or system that integrates micro-sensors, micro-actuators, micro-mechanical structures, micro-power sources, micro-energy, signal processing and control circuits, high-performance electronic integrated devices, interfaces, communications, etc. MEMS is a revolutionary new technology that is widely used in high-tech industries and is a key technology related to the country's scientific and technological development, economic prosperity and national defense security. MEMS focuses on ultra-precision machining, involving many disciplines such as microelectronics, materials, mechanics, chemistry, and mechanics. Its subject area covers various branches of physics, chemistry and mechanics such as force, electricity, light, magnetism, sound and surface at micro scale. Common products include MEMS accelerometers, MEMS microphones, micromotors, micropumps, microvibrators, MEMS optical sensors, MEMS pressure sensors, MEMS gyroscopes, MEMS humidity sensors, MEMS gas sensors and their integrated products.

[0029] The above is only a specific implementation of the utility model, but the protection scope of the utility model is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the utility model, which should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.

Claims

1. A MEMS three-axis acceleration sensor, characterized in that: include: Silicon MEMS acceleration sensors are respectively arranged in three directions of the three-dimensional coordinate system, and the three coordinates of X, Y, and Z are mutually orthogonal, and the silicon MEM acceleration sensors on the coordinate axes do not interfere with each other during operation; The silicon MEM acceleration sensor includes: a silicon frame, and a mass block connected to the silicon frame through a sensitive beam and a supporting beam, and the sensitive beam is provided with a piezoresistor, and the piezoresistor is electrically connected to an external PCB board through a lead to form a Wheatstone bridge; the supporting beam, the sensitive beam and the mass block form an in-plane composite beam structure acceleration sensor structure.

2. The MEMS three-axis acceleration sensor according to claim 1, characterized in that: The sensitive beams are arranged at two opposite end surfaces of the mass block, and the supporting beams are arranged at the other two opposite end surfaces of the mass block, and the axes of the sensitive beams and the supporting beams are both located at the center of the mass block.

3. The MEMS three-axis acceleration sensor according to claim 1 or 2, characterized in that: The thickness of the sensitive beam is smaller than the thickness of the supporting beam, and the thickness of the supporting beam is smaller than the thickness of the mass block.

4. The MEMS three-axis acceleration sensor according to claim 1, characterized in that: The sensitive beam is provided with two pads, and the varistor is connected to each pad through a lead wire; The PCB board has twelve metal pads, and every two adjacent metal pads form a group. At the same time, the two metal pads in each group are electrically connected to the pads of the varistor through wires in a one-to-one correspondence to form a Wheatstone bridge.

5. The MEMS three-axis acceleration sensor according to claim 1, characterized in that: The silicon MEM acceleration sensor on the X-axis of the three-dimensional coordinate system measures the X-axis acceleration value, the silicon MEM acceleration sensor on the Z-axis measures the Z-axis acceleration value, and the silicon MEM acceleration sensor on the Y-axis measures the Y-axis acceleration value.

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