CN101963624A - Silicon micro-resonant accelerometer - Google Patents

Abstract

Translated fromChinese

本发明公开了一种硅微谐振式加速度计，由上下两层构成，上层为制作在单晶硅片上的加速度计机械结构，下层为制作在玻璃衬底上的信号引线，加速度计机械结构由质量块、外框架、两个谐振器、四个一级杠杆放大机构、两个刚性杆和两个导向机构组成，第一、二谐振器对称布置在质量块的上下两侧，该两个谐振器的一端与外框架相连，另一端与导向机构连接；所述的质量块通过四根多折梁与外框架相连，外框架通过四个与质量块的中心对称的固定基座使上层的机械结构部分悬空在下层的玻璃衬底部分之上。本发明大大减小了加工残余应力和工作环境温度变化产生的热应力对结构振动频率的影响，提高了谐振器谐振频率的稳定性，减小了频率的温度系数。

The invention discloses a silicon micro-resonant accelerometer, which is composed of upper and lower layers, the upper layer is the mechanical structure of the accelerometer made on a single crystal silicon wafer, the lower layer is the signal lead wire made on the glass substrate, and the mechanical structure of the accelerometer is It consists of a mass block, an outer frame, two resonators, four primary lever amplification mechanisms, two rigid rods and two guide mechanisms. The first and second resonators are symmetrically arranged on the upper and lower sides of the mass block. The two One end of the resonator is connected to the outer frame, and the other end is connected to the guide mechanism; the mass block is connected to the outer frame through four multi-fold beams, and the outer frame makes the upper layer through four fixed bases symmetrical to the center of the mass block. The mechanical structure part is suspended above the lower glass substrate part. The invention greatly reduces the influence of processing residual stress and thermal stress caused by the temperature change of the working environment on the vibration frequency of the structure, improves the stability of the resonant frequency of the resonator, and reduces the temperature coefficient of the frequency.

Description

Translated fromChinese

硅微谐振式加速度计Silicon Microresonant Accelerometers

技术领域technical field

本发明属于微机电系统MEMS中的微惯性传感器技术，特别是一种硅微谐振式加速度计。The invention belongs to micro-inertia sensor technology in MEMS, in particular to a silicon micro-resonance accelerometer.

背景技术Background technique

硅微加速度计是典型的MEMS惯性传感器，其研究始于20世纪70年代初，现有电容式、压电式、压阻式、热对流、隧道电流式和谐振式等多种形式。硅微谐振式加速度计的独特特点是其输出信号是频率信号，它的准数字量输出可直接用于复杂的数字电路，具有很高的抗干扰能力和稳定性，而且免去了其它类型加速度计在信号传递方面的诸多不便，直接与数字处理器相连。目前美国Draper实验室对谐振式加速度计的研究处于国际领先地位，研究开发的微机械加速度计主要应用于战略导弹，零偏稳定性和标度因数稳定性分别达到5μg和3ppm。因此硅微谐振式加速度计具有良好的发展前景。Silicon micro accelerometer is a typical MEMS inertial sensor. Its research began in the early 1970s, and there are various forms such as capacitive, piezoelectric, piezoresistive, thermal convection, tunnel current and resonance. The unique feature of the silicon microresonant accelerometer is that its output signal is a frequency signal, and its quasi-digital output can be directly used in complex digital circuits, which has high anti-interference ability and stability, and eliminates the need for other types of acceleration In order to avoid the inconvenience of signal transmission, it is directly connected to the digital processor. At present, the research of resonant accelerometer by Draper Laboratory in the United States is in the leading position in the world. The micro-mechanical accelerometer researched and developed is mainly used in strategic missiles, and the bias stability and scale factor stability reach 5μg and 3ppm respectively. Therefore, the silicon microresonant accelerometer has a good development prospect.

硅微谐振式加速度计结构一般由谐振梁和敏感质量块组成，敏感质量块将加速度转换为惯性力，惯性力作用于谐振梁的轴向，使谐振梁的频率发生变化，通过测试谐振频率推算出被测加速度。如2006年，北京航空航天大学樊尚春等针对以往的谐振式加速度计提出一种新的谐振式加速度计(樊尚春，仁杰.一种谐振式微机械加速度计，北京航空航天大学，CN 1844931A)。该结构由质量块、支撑梁、音叉和力学放大系统组成，音叉位于质量块的中间，且相邻上下对称布置，克服了质量块利用率不高的缺点，同时材料不均匀性和环境温度对双音叉的影响一致，可通过差分检测消除环境温度对器件性能的影响，但实际上加工误差使得两个谐振器的谐振频率并不完全相等，作用在两个谐振器上的热应力也不相同，则无法通过差分检测的方式消除热应力的影响。同时，两个音叉相邻布置，电耦合较大。此外，该结构的质量块由位于其中间的两根支撑梁支撑，则加速度计的稳定性和抗冲击能力较差。该结构的支撑梁结构形式为悬臂梁，其释放残余应力的能力较差。The silicon microresonant accelerometer structure is generally composed of a resonant beam and a sensitive mass. The sensitive mass converts acceleration into an inertial force. The inertial force acts on the axial direction of the resonant beam to change the frequency of the resonant beam. The resonant frequency is calculated by testing out of the measured acceleration. For example, in 2006, Fan Shangchun of Beijing University of Aeronautics and Astronautics proposed a new resonant accelerometer for previous resonant accelerometers (Fan Shangchun, Renjie. A resonant micromachined accelerometer, Beijing University of Aeronautics and Astronautics, CN 1844931A) . The structure is composed of a mass block, a support beam, a tuning fork and a mechanical amplification system. The tuning fork is located in the middle of the mass block and arranged symmetrically up and down adjacent to each other, which overcomes the disadvantage of low utilization of the mass block. The influence of the double tuning fork is the same, and the influence of the ambient temperature on the performance of the device can be eliminated through differential detection, but in fact, the processing error makes the resonant frequencies of the two resonators not completely equal, and the thermal stress acting on the two resonators is also different. , the influence of thermal stress cannot be eliminated by means of differential detection. At the same time, the two tuning forks are arranged adjacent to each other, and the electrical coupling is relatively large. In addition, the mass of this structure is supported by two support beams located in the middle, so the stability and impact resistance of the accelerometer are poor. The structural form of the supporting beam of the structure is a cantilever beam, and its ability to release residual stress is poor.

2008年，南京理工大学裘安萍等公开了一种硅微谐振式加速度计(裘安萍，施芹，苏岩.硅微谐振式加速度计，南京理工大学，申请号：2008100255749)，该结构由硅和玻璃两层构成，机械结构制作在单晶硅片上，玻璃作为衬底。机械结构由质量块、谐振器和杠杆放大机构等组成，两个谐振器位于质量块中间，相邻对称布置，质量块由位于其四角的折叠梁支撑，提高了结构的稳定性和抗冲击能力。通过结构的合理设计，该加速度计的量程大于±50g，零启动条件下的零偏稳定性为1.2mg，零偏重复性为0.88mg，标度因数稳定性为380.6ppm。在全温范围内的温度实验发现，加速度计频率的温度系数达160Hz/℃，标度因数的温度系数为0.67％/℃，差分检测的方式并没有完全消除环境温度对器件性能的影响。这是由于加工误差使得两个谐振器的谐振频率并不完全相等，作用在两个谐振器上的热应力也不相同，则无法通过差分检测的方式消除热应力的影响。该结构的两个谐振器直接与固定基座相连，加工残余应力和热应力对谐振频率的影响很大，从而使得速度计的频率温度系数较大。此外，在测试过程中发现该加速度计存在较大的电耦合，当两个谐振器的谐振频率相近时，会产生邻频干扰，从而无法识别所作用的加速度信号。In 2008, Qiu Anping of Nanjing University of Science and Technology disclosed a silicon microresonant accelerometer (Qiu Anping, Shi Qin, Su Yan. Silicon microresonant accelerometer, Nanjing University of Science and Technology, application number: 2008100255749), the structure is composed of silicon and glass Layer composition, the mechanical structure is fabricated on a single crystal silicon wafer, and glass is used as a substrate. The mechanical structure is composed of a mass block, a resonator and a lever amplification mechanism. The two resonators are located in the middle of the mass block and arranged symmetrically adjacent to each other. The mass block is supported by folded beams at its four corners, which improves the stability and impact resistance of the structure. . Through the rational design of the structure, the measuring range of the accelerometer is greater than ±50g, the zero-bias stability is 1.2mg under the zero-start condition, the zero-bias repeatability is 0.88mg, and the scale factor stability is 380.6ppm. Temperature experiments in the full temperature range found that the temperature coefficient of the accelerometer frequency reaches 160Hz/°C, and the temperature coefficient of the scale factor is 0.67%/°C. The differential detection method does not completely eliminate the influence of the ambient temperature on the performance of the device. This is because the resonant frequencies of the two resonators are not completely equal due to processing errors, and the thermal stress acting on the two resonators is also different, so the influence of thermal stress cannot be eliminated by means of differential detection. The two resonators of this structure are directly connected to the fixed base, and the processing residual stress and thermal stress have a great influence on the resonant frequency, so that the frequency temperature coefficient of the speedometer is relatively large. In addition, during the test, it was found that the accelerometer has a large electrical coupling. When the resonant frequencies of the two resonators are similar, adjacent frequency interference will occur, so that the applied acceleration signal cannot be identified.

发明内容Contents of the invention

本发明的目的在于提供一种低温度系数、耦合系数小、灵敏度高、抗冲击能力强、易于实现高精度测量的硅微谐振式加速度计。The object of the present invention is to provide a silicon micro-resonance accelerometer with low temperature coefficient, small coupling coefficient, high sensitivity, strong impact resistance and easy to realize high-precision measurement.

实现本发明目的的技术解决方案为：一种硅微谐振式加速度计，由上下两层构成，上层为制作在单晶硅片上的加速度计机械结构，下层为制作在玻璃衬底上的信号引线，加速度计机械结构由质量块、外框架、两个谐振器、四个一级杠杆放大机构、两个刚性杆和两个导向机构组成，其中质量块、两个谐振器、四个一级杠杆放大机构、两个刚性杆和两个导向机构位于外框架内，质量块位于整体结构的中间，第一、二谐振器对称布置在质量块的上下两侧，该两个谐振器的一端与外框架相连，第一谐振器的另一端与第一导向机构连接，第二谐振器的另一端与第二导向机构连接，第一导向机构与第一刚性杆连接，第二导向机构与第二刚性杆连接；第一、二刚性杆的左右两端与一级杠杆放大机构的输出端相连，该四个一级杠杆放大机构的支点端与外框架相连，输入端与质量块相连；所述的质量块通过四根多折梁与外框架相连，外框架通过四个与质量块的中心对称的固定基座使上层的机械结构部分悬空在下层的玻璃衬底部分之上。The technical solution to realize the object of the present invention is: a silicon microresonant accelerometer, which is composed of upper and lower layers, the upper layer is the accelerometer mechanical structure made on the single crystal silicon chip, and the lower layer is the signal signal made on the glass substrate. Lead wires, the mechanical structure of the accelerometer consists of a mass block, an outer frame, two resonators, four primary lever amplification mechanisms, two rigid rods and two guiding mechanisms, of which the mass block, two resonators, four primary The lever amplification mechanism, two rigid rods and two guide mechanisms are located in the outer frame, the mass block is located in the middle of the overall structure, the first and second resonators are symmetrically arranged on the upper and lower sides of the mass block, and one end of the two resonators is connected to the The outer frame is connected, the other end of the first resonator is connected with the first guiding mechanism, the other end of the second resonator is connected with the second guiding mechanism, the first guiding mechanism is connected with the first rigid rod, the second guiding mechanism is connected with the second Rigid rod connection; the left and right ends of the first and second rigid rods are connected with the output end of the first-level lever amplification mechanism, the fulcrum ends of the four first-level lever amplification mechanisms are connected with the outer frame, and the input ends are connected with the mass block; The mass block is connected to the outer frame through four multi-fold beams, and the outer frame suspends the mechanical structure part of the upper layer above the glass substrate part of the lower layer through four fixed bases symmetrical to the center of the mass block.

本发明与现有技术相比，其显著优点：(1)该加速度计的谐振器、杠杆和质量块都通过外框架与固定基座相连，大大减小了加工残余应力和工作环境温度变化产生的热应力对结构振动频率的影响，提高了谐振器谐振频率的稳定性，减小了频率的温度系数；(2)每个谐振器的谐振梁由两根梁组成，且梁的中间相连，实现了双边驱动，降低了高阶模态的干扰；(3)两个谐振器位于质量块的上下两端，增加了电信号之间的空间距离，大大减小电耦合；(4)一级杠杆放大机构的支点端和输出端都采用了细梁结构，输入梁采用了多折梁结构，从而支点端和输出端的轴向拉伸刚度很大而弯曲刚度很小，且支点端细梁的轴向与杠杆轴向相互垂直，实现了放大倍数接近传统杠杆放大机构的理论值；(5)一级杠杆放大机构的输出端通过刚性杆与谐振器连接，刚性杆的y方向刚度较大，可以有效地将杠杆输出的惯性力传递给谐振梁；(6)导向机构在x轴有很大的刚度，大大减小了x轴的交叉轴灵敏度；(7)质量块通过四根轴对称多折梁与外框架相连，提高了加速度计结构的稳定性和抗冲击能力；(8)质量块与外框架之间相连的多折梁在x轴有很大的刚度，则很好地隔离了x方向运动对加速度计性能的影响，而y轴刚度较小，可实现y方向能量较大地传递给杠杆放大机构，从而提高加速度计灵敏度。Compared with the prior art, the present invention has significant advantages: (1) the resonator, lever and mass block of the accelerometer are all connected to the fixed base through the outer frame, which greatly reduces the processing residual stress and the temperature change of the working environment. The influence of the thermal stress on the vibration frequency of the structure improves the stability of the resonant frequency of the resonator and reduces the temperature coefficient of the frequency; (2) The resonant beam of each resonator is composed of two beams, and the middle of the beams is connected. The bilateral drive is realized, which reduces the interference of high-order modes; (3) The two resonators are located at the upper and lower ends of the mass block, which increases the spatial distance between electrical signals and greatly reduces electrical coupling; (4) One-stage lever amplification Both the fulcrum end and the output end of the mechanism adopt a thin beam structure, and the input beam adopts a multi-fold beam structure, so that the axial tensile stiffness of the fulcrum end and the output end is very large and the bending stiffness is small, and the axial stiffness of the thin beam at the fulcrum end It is perpendicular to the axial direction of the lever, and the magnification factor is close to the theoretical value of the traditional lever amplifying mechanism; (5) the output end of the first-stage lever amplifying mechanism is connected to the resonator through a rigid rod, and the rigid rod has a large stiffness in the y direction, which can effectively The inertial force output by the lever is transmitted to the resonant beam efficiently; (6) the guide mechanism has a large stiffness in the x-axis, which greatly reduces the cross-axis sensitivity of the x-axis; (7) the mass block passes through four axisymmetric multi-fold beams It is connected with the outer frame, which improves the stability and impact resistance of the accelerometer structure; (8) the multi-fold beam connected between the mass block and the outer frame has a large stiffness in the x-axis, which well isolates the x-direction The impact of motion on the performance of the accelerometer, while the y-axis stiffness is small, can achieve a large energy transfer in the y-direction to the lever amplification mechanism, thereby improving the sensitivity of the accelerometer.

下面结合附图对本发明作进一步详细描述。The present invention will be described in further detail below in conjunction with the accompanying drawings.

附图说明Description of drawings

图1是本发明的硅微谐振式加速度计的结构示意图。FIG. 1 is a schematic structural view of the silicon microresonant accelerometer of the present invention.

图2是本发明的谐振器和一级杠杆放大机构的结构示意图。Fig. 2 is a structural schematic diagram of the resonator and the first-stage lever amplification mechanism of the present invention.

具体实施方式Detailed ways

结合图1，本发明基于谐振式的硅微加速度计，用于测量平行于基座水平的测量仪器，由上下两层构成，上层为制作在单晶硅片上的加速度计机械结构，下层为制作在玻璃衬底上的信号引线。加速度计的机械结构由质量块1、外框架2、一对谐振器3a、3b和四个完全相同的一级杠杆放大结构4a、4b、4c、4d、两个刚性杆7a、7b和两个导向机构8a、8b组成，其中质量块1、两个谐振器3a、3b、四个一级杠杆放大机构4a、4b、4c、4d、两个刚性杆7a、7b和两个导向机构8a、8b位于外框架2内。质量块1布置在加速度计结构的中间，第一、二谐振器3a、3b上下对称布置在质量块1的上下两端，该两个谐振器3a、3b的一端与外框架2相连，第一谐振器3a的另一端与第一导向机构8a连接，第二谐振器3b的另一端与第二导向机构8b连接，第一导向机构8a与第一刚性杆7a连接，第二导向机构8b与第二刚性杆7b连接；第一、二刚性杆7a、7b的左右两端与一级杠杆放大机构4a、4b、4c、4d的输出端相连，该四个一级杠杆放大机构4a、4b、4c、4d的支点端与外框架2相连，输入端与质量块1相连。所述的质量块1通过四根多折梁6a、6b、6c、6d与外框架2相连，外框架2通过四个与质量块1的中心对称的固定基座5a、5b、5c、5d使上层的机械结构部分悬空在下层的玻璃衬底部分之上。这样两个谐振器3a、3b的一端通过外框架2与固定基座5a、5b、5c、5d相连，减小了残余应力以及热应力对谐振器谐振频率的影响，大大减小频率的温度系数。In conjunction with Fig. 1, the present invention is based on the resonant silicon micro-accelerometer, which is used to measure the measuring instrument parallel to the base level. Signal leads fabricated on a glass substrate. The mechanical structure of the accelerometer consists of a mass block 1, anouter frame 2, a pair ofresonators 3a, 3b and four identical primarylever amplification structures 4a, 4b, 4c, 4d, tworigid rods 7a, 7b and twoGuide mechanism 8a, 8b is composed of mass block 1, tworesonators 3a, 3b, four primarylever amplification mechanisms 4a, 4b, 4c, 4d, tworigid rods 7a, 7b and twoguide mechanisms 8a, 8b Located in theouter frame 2. The mass block 1 is arranged in the middle of the accelerometer structure, and the first andsecond resonators 3a, 3b are symmetrically arranged at the upper and lower ends of the mass block 1. One end of the tworesonators 3a, 3b is connected to theouter frame 2, and the first The other end of theresonator 3a is connected to thefirst guide mechanism 8a, the other end of the second resonator 3b is connected to thesecond guide mechanism 8b, thefirst guide mechanism 8a is connected to the first rigid rod 7a, and thesecond guide mechanism 8b is connected to thesecond guide mechanism 8b. Tworigid rods 7b are connected; the left and right ends of the first and secondrigid rods 7a, 7b are connected to the output ends of the primarylever amplification mechanisms 4a, 4b, 4c, 4d, and the four primarylever amplification mechanisms 4a, 4b, 4c The fulcrum end of , 4d is connected with theouter frame 2 , and the input end is connected with the quality block 1 . The mass block 1 is connected with theouter frame 2 through fourmulti-fold beams 6a, 6b, 6c, 6d, and theouter frame 2 is made by fourfixed bases 5a, 5b, 5c, 5d symmetrical to the center of the mass block 1. The upper part of the mechanical structure is suspended above the lower part of the glass substrate. In this way, one end of the tworesonators 3a, 3b is connected to thefixed base 5a, 5b, 5c, 5d through theouter frame 2, which reduces the influence of residual stress and thermal stress on the resonant frequency of the resonator, and greatly reduces the temperature coefficient of frequency .

各一级杠杆放大机构4a、4b、4c、4d都一样，即其输出端13a、13b(每个一级杠杆放大机构都一个输出端，在图2中仅标出了其中两个输出端13a、13b)依次通过刚性杆7a、7b和导向机构8a、8b与谐振器3a、3b相连，导向机构8a、8b的两端与外框架2相连，使导向机构8a、8b在x方向具有很大的刚度，而在y方向刚度较小，较好地隔离了x方向运动对谐振器的影响。第一刚性杆7a左右两端与两个一级杠杆放大机构4a、4b的输出端相连，第二刚性杆7b左右两端与两个一级杠杆放大机构4c、4d的输出端相连。两个刚性杆7a、7b的y方向刚度较大，可以有效地将杠杆输出的惯性力传递给谐振梁。四个一级杠杆放大机构4a、4b、4c、4d的支点端通过外框架2与四个固定基座5a、5b、5c、5d相连，四个一级杠杆放大机构4a、4b、4c、4d的输入端11a、11b与质量块1相连(每个一级杠杆放大机构都一个输入端，在图2中仅标出了其中两个输入端11a、11b)，减小了残余应力以及热应力对杠杆放大倍数的影响。质量块1通过四根多折梁6a、6b、6c、6d与外框架2相连，增加了加速度计的稳定性，并提高其抗冲击能力，且轴对称的多折梁6a、6b、6c、6d不仅有效地释放残余应力，降低交叉轴灵敏度。外框架2通过固定基座5a、5b、5c、5d使上层的机械结构部分悬空在下层的玻璃衬底部分之上，两个谐振器3a、3b、四个一级杠杆放大机构4a、4b、4c、4d以及四根多折梁6a、6b、6c、6d通过外框架2与四个基座5a、5b、5c、5d相连，大大减小了加工残余应力以及环境变化产生的热应力对加速度计性能的影响。四根多折梁6a、6b、6c、6d是轴对称结构，各多折梁6a、6b、6c、6d在x方向具有较大的刚度，较好地隔离了x方向运动对谐振器的影响，而在y方向刚度较小，可实现y方向能量较大地传递给杠杆放大机构，从而提高加速度计灵敏度。Each one-level lever amplifyingmechanism 4a, 4b, 4c, 4d is all the same, namely itsoutput end 13a, 13b (all one output end of each one-level lever amplifying mechanism, only marked wherein twooutput ends 13a in Fig. 2 , 13b) are connected to theresonators 3a, 3b throughrigid rods 7a, 7b andguide mechanisms 8a, 8b in turn, and the two ends of theguide mechanisms 8a, 8b are connected to theouter frame 2, so that theguide mechanisms 8a, 8b have a large The stiffness in the y direction is smaller, which better isolates the influence of the movement in the x direction on the resonator. The left and right ends of the first rigid rod 7a are connected to the output ends of the two primarylever amplifying mechanisms 4a, 4b, and the left and right ends of the secondrigid rod 7b are connected to the output ends of the two primarylever amplifying mechanisms 4c, 4d. The y-direction stiffness of the tworigid rods 7a and 7b is relatively large, which can effectively transmit the inertial force output by the levers to the resonant beam. The fulcrum ends of the four primarylever amplifying mechanisms 4a, 4b, 4c, 4d are connected to the four fixedbases 5a, 5b, 5c, 5d through theouter frame 2, and the four primarylever amplifying mechanisms 4a, 4b, 4c, 4d Theinput ends 11a, 11b of the input end are connected to the mass block 1 (each first-stage lever amplifying mechanism has an input end, and only two of theinput ends 11a, 11b are marked in Fig. 2), which reduces residual stress and thermal stress Effect on leverage magnification. The mass block 1 is connected to theouter frame 2 through fourmulti-fold beams 6a, 6b, 6c, 6d, which increases the stability of the accelerometer and improves its impact resistance, and the axisymmetricmulti-fold beams 6a, 6b, 6c, 6d not only effectively releases residual stress but also reduces cross-axis sensitivity. Theouter frame 2 suspends the mechanical structure part of the upper layer above the glass substrate part of the lower layer by fixing thebase 5a, 5b, 5c, 5d, tworesonators 3a, 3b, four primarylever amplification mechanisms 4a, 4b, 4c, 4d and the fourmulti-fold beams 6a, 6b, 6c, 6d are connected to the fourbases 5a, 5b, 5c, 5d through theouter frame 2, which greatly reduces the processing residual stress and the thermal stress caused by environmental changes on the acceleration impact on meter performance. The fourmulti-fold beams 6a, 6b, 6c, and 6d are axisymmetric structures, and eachmulti-fold beam 6a, 6b, 6c, and 6d has greater stiffness in the x direction, which better isolates the influence of the movement in the x direction on the resonator , and the stiffness in the y direction is small, so that the energy in the y direction can be transferred to the lever amplification mechanism with a large amount, thereby improving the sensitivity of the accelerometer.

第一、二谐振器3a、3b结构相同，结构如图2所示，即每个谐振器由两根谐振梁14a、14b、两个固定驱动电极15a、15b、四个固定检测电极16a、16b、16c、16d以及活动梳齿17组成，两根谐振梁14a、14b的中间部分相连，，减小了干扰模态。采用双边驱动，即在两根谐振梁14a、14b的两侧布置了活动梳齿17，在活动梳齿17的外侧布置了驱动电极15a、15b和内侧布置了四个固定检测电极16a、16b、16c、16d，活动梳齿17与驱动电极15a、15b和固定检测电极16a、16b、16c、16d上的固定梳齿对插形成驱动电容和检测电容，具体是固定驱动电极15a、15b上的固定梳齿与活动梳齿17形成驱动电容，在固定驱动电极15a、15b上施加带直流偏置的反相交流电压。活动梳齿17与固定检测电极16a、16b、16c、16d组成检测电容。The first andsecond resonators 3a, 3b have the same structure, as shown in Figure 2, that is, each resonator consists of tworesonant beams 14a, 14b, two fixeddrive electrodes 15a, 15b, and fourfixed detection electrodes 16a, 16b , 16c, 16d andmovable comb teeth 17, and the middle parts of the tworesonant beams 14a, 14b are connected to reduce the interference mode. Two-sided driving is adopted, that is,movable comb teeth 17 are arranged on both sides of the tworesonant beams 14a, 14b, drivingelectrodes 15a, 15b are arranged on the outer side of themovable comb teeth 17, and fourfixed detection electrodes 16a, 16b, 16c, 16d, themovable comb teeth 17 and the fixed comb teeth on thedrive electrodes 15a, 15b and thefixed detection electrodes 16a, 16b, 16c, 16d are intersected to form a drive capacitor and a detection capacitor, specifically the fixeddrive electrodes 15a, 15b. The comb teeth and themovable comb teeth 17 form a drive capacitor, and an anti-phase AC voltage with a DC bias is applied to the fixeddrive electrodes 15a and 15b. Themovable comb teeth 17 and the fixeddetection electrodes 16a, 16b, 16c, 16d form a detection capacitance.

四个一级杠杆放大机构4a、4b、4c、4d结构相同，结构如图2所示，如一级杠杠放大机构4a、4b由杠杆10a、10b、支点端12a、12b、输出端13a、13b、和输入端11a、11b组成。对于微杠杆而言，当支点端和输出端的轴向拉伸刚度越大，而支点梁和输出端的弯曲刚度越小时，杠杆的放大倍数才会接近理想值，支点端12a、12b和输出端13a、13b皆采用细梁结构，输入端11a、11b的梁为轴对称的多折梁。支点端细梁12a、12b的轴向与杠杆10a、10b轴向相互垂直，这也使得杠杆的放大倍数接近理想值。Four primarylever amplifying mechanisms 4a, 4b, 4c, 4d have the same structure, as shown in Fig. And theinput terminal 11a, 11b composition. For the micro-lever, when the axial tensile stiffness of the fulcrum end and the output end is larger, and the bending stiffness of the fulcrum beam and the output end is smaller, the magnification of the lever will be close to the ideal value. The fulcrum ends 12a, 12b and theoutput end 13a Both 13b and 13b adopt a thin beam structure, and the beams at the input ends 11a and 11b are axisymmetric multi-fold beams. The axial directions of thethin beams 12a, 12b at the fulcrum ends are perpendicular to the axial directions of thelevers 10a, 10b, which also makes the magnification of the levers close to the ideal value.

本发明的硅微谐振式加速度计用于测量y方向的输入加速度，当有沿y方向的加速度a输入时，在质量块上产生惯性力F＝-ma，该惯性力分别作用于四个一级杠杆放大机构上，在杠杆放大的作用下，作用于谐振器每根谐振梁上的作用力为The silicon microresonant type accelerometer of the present invention is used for measuring the input acceleration of y direction, when there is the acceleration a input along y direction, produces inertial force F=-ma on mass block, and this inertial force acts on four one respectively On the level lever amplification mechanism, under the action of lever amplification, the force acting on each resonant beam of the resonator is

${\mathrm{<span><span>F</span>f</span>}}_{\mathrm{<span><span>B</span>B</span>}}<span><span>=</span>=</span><span><span>-</span>-</span>\frac{\mathrm{<span><span>Ama</span>Ama</span>}}{\mathrm{<span><span>4</span>4</span>}}$

式中，A为一级杠杆放大机构的放大倍数。其中上谐振器受到的力为压力，谐振频率减小，而下谐振器的受到的力为拉力，谐振频率增大，两个谐振器的频率差为In the formula, A is the magnification factor of the first-stage lever magnification mechanism. The force on the upper resonator is pressure, and the resonance frequency decreases, while the force on the lower resonator is tension, and the resonance frequency increases. The frequency difference between the two resonators is

Δf＝2f₀κAmaΔf=2f₀ κAma

式中，κ为与谐振梁结构参数相关的常数。可见，上下谐振器的频率差与输入加速度成正比，通过检测上下谐振器的频率差，则测量输入加速度。In the formula, κ is a constant related to the structural parameters of the resonant beam. It can be seen that the frequency difference between the upper and lower resonators is proportional to the input acceleration, and the input acceleration can be measured by detecting the frequency difference between the upper and lower resonators.

Claims (5)

1. silicon micro-resonance type accelerometer, constitute by two-layer up and down, the upper strata is the accelerometer physical construction that is produced on the monocrystalline silicon piece, lower floor is the signal lead that is produced on the glass substrate, it is characterized in that: accelerometer physical construction is by mass (1), outside framework (2), two resonator (3a, 3b), four one-level lever enlarger (4a, 4b, 4c, 4d), two rigid rod (7a, 7b) with two guiding mechanism (8a, 8b) form, mass (1) wherein, two resonator (3a, 3b), four one-level lever enlarger (4a, 4b, 4c, 4d), two rigid rod (7a, 7b) with two guiding mechanism (8a, 8b) be positioned at outside framework (2), mass (1) is positioned at integrally-built centre, first, two resonator (3a, 3b) be arranged symmetrically in the two ends up and down of mass (1), these two resonator (3a, end 3b) links to each other with outside framework (2), the other end of first resonator (3a) is connected with first guiding mechanism (8a), the other end of second resonator (3b) is connected with second guiding mechanism (8b), first guiding mechanism (8a) is connected with first rigid rod (7a), and second guiding mechanism (8b) is connected with second rigid rod (7b); The two ends, the left and right sides of first and second rigid rod (7a, 7b) link to each other with the output terminal of one-level lever enlarger (4a, 4b, 4c, 4d), the support end of these four one-level lever enlargers (4a, 4b, 4c, 4d) links to each other with outside framework (2), and input end links to each other with mass (1); Described mass (1) links to each other with outside framework (2) by folding beam (6a, 6b, 6c, 6d) more than four, and outside framework (2) is unsettled on the glass substrate part of lower floor by the physical construction part that four centrosymmetric fixed pedestals (5a, 5b, 5c, 5d) with mass (1) make the upper strata.

2. silicon micro-resonance type velograph according to claim 1, it is characterized in that: four one-level lever enlargers (4a, 4b, 4c, 4d) structure is identical, its support end (12a) and output terminal (13a) have all adopted slender beam, and input end (11a) has adopted axisymmetric many folding girder constructions.

3. silicon micro-resonance type accelerometer according to claim 1, it is characterized in that: the output terminal (13a) of each one-level lever enlarger (4a, 4b, 4c, 4d) links to each other with resonator (3a) with guiding mechanism (8a) by rigid rod (7a) successively, the two ends of guiding mechanism (8a) link to each other with outside framework (2), make guiding mechanism (8a) have very big rigidity in the x direction, and less in y direction rigidity.

4. silicon micro-resonance type accelerometer according to claim 1, it is characterized in that: first, two resonator (3a, 3b) structure is identical, be that each resonator is by two resonance beam (14a, 14b), two fixed drive electrode (15a, 15b), four fixed test electrode (16a, 16b, 16c, 16d) and movable broach (17) form, two resonance beam (14a, center section 14b) links to each other, adopt bilateral driving, promptly at two resonance beam (14a, movable broach (17) has been arranged in both sides 14b), drive electrode (15a has been arranged in the outside at movable broach (17), 15b) and disposed inboard four fixed test electrode (16a, 16b, 16c, 16d), movable broach (17) and drive electrode (15a, 15b) with fixed test electrode (16a, 16b, 16c, fixed fingers 16d) drives electric capacity and detects electric capacity inserting to form.

5. silicon micro-resonance type accelerometer according to claim 1 is characterized in that: folding beam (6a, 6b, 6c, 6d) is an axially symmetric structure more than four.

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