Two-stage-sealing low-temperature-coefficient all-quartz resonant accelerometer structure and assembling method

Abstract

The invention relates to a two-stage-sealing low-temperature-coefficient all-quartz resonant accelerometer structure and an assembling method, and the accelerometer structure comprises a mounting base, the mounting base is connected with a lower isolation plate, the lower isolation plate is provided with a quartz mass pendulum structure, and the quartz mass pendulum structure is provided with an upper isolation plate. The upper isolation plate, the quartz mass pendulum structure and the lower isolation plate are connected to the mounting base through positioning lead columns, and a shell arranged on the outer side of the upper isolation plate is connected to the mounting base; the sealing performance of the quartz resonance accelerometer is improved, the stability of the accelerometer is improved, and the temperature drift and the size of the quartz resonance accelerometer are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of accelerometers, and in particular to a two-stage sealed, low temperature coefficient all-quartz resonant accelerometer structure and an assembly method. Background Art

[0002] Inertial navigation is the foundation of precision strike, and accelerometers are one of their core instruments. Their accuracy determines the strike capability of weapons and equipment. With technological advancements, weapon models are placing increasingly stringent requirements on accelerometer size, precision, and reliability. Existing accelerometers fall short of future equipment requirements. Quartz resonant accelerometers, with their compact size, high-precision potential, digital output, and strong environmental adaptability, are considered by the industry to represent the next generation of high-precision accelerometers. Their direct digital output effectively reduces the accuracy errors introduced by analog-to-digital conversion, while also saving space on analog-to-digital converter boards in inertial navigation systems. This adapts to the trend toward miniaturization of inertial navigation systems, making them a hot topic of research at research institutes worldwide.

[0003] The working principle of the quartz resonant accelerometer is: when the external acceleration input is loaded onto the sensitive mass block, the resonant beam is attached to the mass block, and the mass block drives the resonant beam to be sensitive to the applied acceleration. Since the resonant beam has a piezoelectric effect, the acceleration acts on the resonant beam, changing the resonant frequency of the resonant beam. The change in the resonant frequency has a certain linear relationship with the external input acceleration. The resonance detection circuit obtains the acceleration input value by detecting the change in the resonant beam frequency.

[0004] As the core instrument of the inertial navigation acceleration channel, the quartz resonant accelerometer has a theoretical accuracy of up to 1.0E-07. With the improvement of quartz material performance and MEMS process level, the accuracy and reliability of quartz resonant accelerometer will reach a higher level. Quartz resonant accelerometer will have broad application prospects in aviation, aerospace, navigation, weapons and other fields.

[0005] However, existing quartz resonant accelerometers have the following shortcomings: 1) Sealing determines the accelerometer's ability to withstand humid and hot environments. Existing quartz resonant accelerometers lack sealing around the sensitive chip, relying solely on the housing for single-stage sealing. This sealing level needs to be further improved. 2) The mass-sensing structure and resonant beam in existing quartz resonant accelerometers are made of inconsistent materials (Levy R, Bourgeteau B, Guerard J, et al. A high precision quartz crystal MEMS accelerometer based 2-axis inclinometer [C] / / 2016 Symposium on Design, Test, Integration and Packaging of MEMS / MOEMS (DTIP). IEEE, 2016.). This causes relative creep between the dissimilar materials when the temperature changes, affecting the temperature characteristics of the accelerometer's bias and scale factor. 3) The large temperature coefficient of existing quartz resonant accelerometers affects their practical applications (Li C, Zhao Y, Li B, et al. A micro-machined differential resonance accelerometer based on silicon on quartz method [J]. SENSORS AND ACTUATORS A-PHYSICAL, 2016: S0924424716308329.), and their stability under actual working conditions needs to be further improved. Summary of the Invention

[0006] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a two-stage sealed, low temperature coefficient all-quartz resonant accelerometer structure and assembly method, which improves the sealing of the quartz resonant accelerometer, improves the stability of the accelerometer, and reduces the temperature drift and volume of the quartz resonant accelerometer.

[0007] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions:

[0008] A two-stage sealed, low temperature coefficient all-quartz resonant accelerometer structure includes a mounting base 1, a lower isolation plate 4 is connected to the mounting base 1, a quartz mass pendulum structure 7 is mounted on the lower isolation plate 4, an upper isolation plate 17 is mounted on the quartz mass pendulum structure 7, the upper isolation plate 17, the quartz mass pendulum structure 7, and the lower isolation plate 4 are connected to the mounting base 1 via positioning lead columns 2, and a housing 20 is provided on the outer side of the upper isolation plate 17 and connected to the mounting base 1.

[0009] The mounting base 1 is made of 0Cr18Ni9Ti metal material. The four positioning lead columns 2 and the four signal output columns 3 are fixed to the mounting base 1 by sintering. The four positioning lead columns 2 are plated with gold film. The lead-out gold wire of the resonant beam is welded to the positioning lead column 2, and the output signal of the resonant beam is led out to the resonant circuit.

[0010] The lower isolation plate 4 is made of single crystal quartz glass, and has four lower positioning holes 5 corresponding to the four positioning lead posts 2. The outer ring is coated with adhesive, and the mounting base 1 and the lower isolation plate 4 are matched through the adhesive, the positioning lead posts 2, and the lower positioning holes 5.

[0011] The mass pendulum fixing boss 8 on the outside of the quartz mass pendulum structure 7 corresponds to the first quartz mass pendulum mounting hole 6 on the lower isolation plate 4, and precise matching is achieved through adhesive; the upper resonant beam 15 and the lower resonant beam 16 are respectively attached to the upper and lower parts of the quartz mass pendulum structure 7; the quartz mass pendulum structure 7 is plated with a resonant beam positioning and a lower resonant beam conductive gold film 14, the function of which is to realize the positioning of the resonant beam and at the same time lead out the electrical signal of the lower resonant beam through the conductive positive and negative electrodes; the outer ring mounting frame 9 on the outside of the quartz mass pendulum structure 7 is respectively matched with the inner circular holes of the lower isolation plate 4 and the upper isolation plate 17; the trapezoidal stress isolation area 10 inside the quartz mass pendulum structure 7 isolates temperature stress and reduces the temperature coefficient; the mass pendulum tongue 11 and the flexible support 12 inside the quartz mass pendulum structure 7 transmit external input acceleration; the resonant beam vibration groove 13 provides a vibration space for the resonant beam.

[0012] The upper positioning holes 18 of the upper isolation plate 17 correspond to the four positioning lead columns 2 respectively, and the second quartz mass pendulum mounting holes 19 of the upper isolation plate 17 correspond to the mass pendulum fixing bosses 8 of the quartz mass pendulum structure 7 respectively, thereby realizing the coordination between the upper isolation plate 17 and the quartz mass pendulum structure 7.

[0013] The lower isolation plate 4, quartz mass pendulum structure 7, and upper isolation plate 17 are precisely matched with each other through sealant to achieve the first-level sealing of the watch movement; the outer shell 20 uses 0Cr18Ni9Ti material, is consistent with the mounting base 1, and is laser welded with the mounting base 1 to achieve the second-level sealing.

[0014] The assembly method of the two-stage sealed, low temperature coefficient all-quartz resonant accelerometer structure comprises the following steps:

[0015] 1) Place the mounting base 1 on the mounting and positioning fixture, and pass the four positioning lead posts 2 through the resonant circuit and sinter them on the mounting base 1;

[0016] 2) The outer circle of the lower isolation plate 4 matches the inner circle of the mounting base 1. The lower isolation plate 4 is etched with lower positioning holes 5 that are clearance-matched with the four positioning lead posts 2 of the mounting base 1. At the same time, the lower isolation plate 4 is etched with quartz mass pendulum mounting holes to provide installation space for the mass pendulum fixing boss 8;

[0017] 3) The quartz mass pendulum structure 7 has a mass pendulum fixing boss 8 that cooperates with the mounting holes of the upper isolation plate 17 and the lower isolation plate 4. The trapezoidal stress isolation area 10 of the quartz mass pendulum structure 7 passes through four positioning lead pins;

[0018] 4) The gold wire lead of the lower resonant beam 16 is welded to the conductive gold film on the bottom surface of the quartz mass pendulum structure 7. The lower conductive gold film is connected to the upper conductive gold film through the gold film on the side. The signal of the upper resonant beam 15 is directly welded to the positioning lead post 2. The lead signal of the lower resonant beam 16 is welded to the positioning lead post 2 through the resonant beam positioning and the conductive gold film of the lower resonant beam, so that the output signals of the upper resonant beam 15 and the lower resonant beam 16 are transmitted to the resonant circuit;

[0019] 5) The inner circle of the upper isolation plate 17 matches the outer circle of the quartz mass pendulum structure 7. The upper isolation plate 17 is etched with upper positioning holes 18 to fit the four positioning lead pins 2 of the mounting base 1. At the same time, the upper isolation plate 17 is etched with quartz mass pendulum mounting holes 19 to provide installation space for the mass pendulum fixing boss 8;

[0020] 6) The housing 20 is fixedly connected to the mounting base 1 by laser welding.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] (A) The upper and lower isolation plates of the present invention are positioned by positioning lead pins. The upper and lower isolation plates and the quartz mass pendulum structure cooperate with the fixed bosses through the mounting holes to form a first-level full seal of the watch movement; the outer shell is laser welded to the mounting base to form a second-level seal. The two-level seal improves the sealing of the accelerometer and ensures strong environmental adaptability.

[0023] (B) The quartz mass pendulum structure of the present invention is designed with a trapezoidal stress isolation zone 10. By performing finite element simulation on a circle, a quadrilateral, a trapezoid, etc., it is found that the trapezoidal structure can minimize the temperature stress interference.

[0024] (C) The quartz mass pendulum structure and the upper and lower isolation plates of the present invention are all made of single crystal quartz glass, which eliminates the mismatch of heterogeneous materials and improves the stability of the accelerometer.

[0025] (D) The all-quartz resonant accelerometer of the present invention has a simple structure and a size of Compared with existing quartz flexible accelerometers with the same interface, the device is smaller in size. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a cross-sectional view of the structure of the all-quartz resonant accelerometer according to an embodiment of the present invention.

[0027] Figure 2 1 and 2 are a top view and a cross-sectional view of the mounting base according to an embodiment of the present invention.

[0028] Figure 3 1 and 2 are top and cross-sectional views of the lower isolation plate according to an embodiment of the present invention.

[0029] Figure 4 2. It is a top view of the upper isolation plate according to an embodiment of the present invention.

[0030] Figure 5 1. It is a top view of the quartz mass pendulum structure according to an embodiment of the present invention.

[0031] Figure 6 2 is a top view of the resonant beam according to an embodiment of the present invention.

[0032] Figure 7 It is a cross-sectional view of the shell of an embodiment of the present invention.

[0033] Among them: 1-mounting base, 2-positioning lead column, 3-signal output column, 4-lower isolation plate, 5-lower positioning hole, 6-first quartz mass pendulum mounting hole, 7-quartz mass pendulum structure, 8-mass pendulum fixing boss, 9-outer ring mounting frame, 10-trapezoidal stress isolation area, 11-mass pendulum tongue, 12-flexible support, 13-resonance beam vibration groove, 14-resonance beam positioning and lower resonant beam conductive gold film, 15-upper resonant beam, 16-lower resonant beam, 17-upper isolation plate, 18-upper positioning hole, 19-second quartz mass pendulum mounting hole, 20-housing. DETAILED DESCRIPTION

[0034] The present invention is described in detail below with reference to the embodiments and drawings. It should be noted that the present invention is not limited to the following embodiments, and any equivalent changes made on the basis of the technical solution of this application fall within the protection scope of the present invention.

[0035] like Figures 1-6 As shown, a two-stage sealed, low temperature coefficient all-quartz resonant accelerometer structure includes a mounting base 1, a lower isolation plate 4, a quartz mass pendulum structure 7, an upper resonant beam 15, a lower resonant beam 16, an upper isolation plate 17, and a housing 20; the mounting base 1 is connected to the lower isolation plate 4, the quartz mass pendulum structure 7 is mounted on the lower isolation plate 4, the quartz mass pendulum structure 7 is mounted on the upper isolation plate 17, the upper isolation plate 17, the quartz mass pendulum structure 7, and the lower isolation plate 4 are connected to the mounting base 1 through a positioning lead column 2, and the housing 20 provided on the outer side of the upper isolation plate 17 is connected to the mounting base 1.

[0036] Mounting base 1: The mounting base 1 is made of 0Cr18Ni9Ti metal material, and a positioning lead column 2 and a signal output column 3 are sintered on the mounting base 1; the function of the positioning lead column 2 is to complete the precise positioning of the upper isolation plate 17 and the lower isolation plate 4, and output the output signals of the upper resonant beam 15 and the lower resonant beam 16 through gold wire welding on the positioning lead column 2; the function of the signal output column 3 is to amplify the resonant beam signal inside the accelerometer through the resonant circuit and output it to the outside.

[0037] Upper and lower isolation plates: The material of the upper isolation plate 17 and the lower isolation plate 4 is single crystal quartz. The upper isolation plate 17 and the lower isolation plate 4 are respectively designed with upper positioning holes 18 and lower positioning holes 5. The function of the positioning holes is to achieve precise matching with the positioning lead column 2 of the mounting base 1; the first quartz mass pendulum mounting hole 6 of the lower isolation plate 4 and the second quartz mass pendulum mounting hole 19 of the upper isolation plate 17 both provide installation references for the quartz mass pendulum structure 7 to achieve precise matching.

[0038] Quartz mass pendulum structure 7: The material is single crystal quartz glass, and the mass pendulum fixing boss 8 is designed to correspond to the upper isolation plate 17, the second quartz mass pendulum mounting hole 19 of the lower isolation plate 4, and the first quartz mass pendulum mounting hole 6, respectively, and is precisely matched by adhesive; the upper and lower parts of the quartz mass pendulum structure 7 are respectively attached with the upper resonant beam 15 and the lower resonant beam 16; the quartz mass pendulum structure 7 is plated with a resonant beam positioning and a conductive gold film 14 for the lower resonant beam. The function of the resonant beam positioning and the conductive gold film 14 for the lower resonant beam is to realize the resonant beam positioning and at the same time lead out the electrical signal of the lower resonant beam through the conductive positive and negative electrodes; Quartz The outer ring mounting frame 9 on the outside of the mass pendulum structure 7 cooperates with the inner circle of the upper isolation plate 17 and the lower isolation plate 4; the trapezoidal stress isolation area 10 inside the quartz mass pendulum structure 7 is a temperature stress isolation structure; the mass pendulum tongue 11 inside the quartz mass pendulum structure 7 is a sensitive mass block, which converts the external input acceleration into the axial stress of the resonant beam; the flexible support 12 balances the external input inertial force; the resonant beam vibration groove 13 provides vibration space for the upper resonant beam 15 and the lower resonant beam 16; the resonant beam positioning and the lower resonant beam conductive gold film 14 realize the positioning of the resonant beam mounting and the lead-out function of the output signal of the lower resonant beam 16.

[0039] Upper and lower resonant beams: The material is Z-cut single crystal quartz glass. The external input acceleration is converted into axial stress of the resonant beam through the mass tongue 11. Based on the inverse piezoelectric effect, the upper resonant beam 15 and the lower resonant beam 16 vibrate. When the external input acceleration changes, the vibration frequency of the upper resonant beam 15 and the lower resonant beam 16 changes, and the changing frequency is proportional to the external input acceleration.

[0040] Shell 20: is laser welded on the mounting base 1 to complete the packaging of the watch movement.

[0041] The assembly method of the two-stage sealed, low temperature coefficient all-quartz resonant accelerometer structure comprises the following steps:

[0042] 1) Place the mounting base 1 on the mounting and positioning fixture as the installation reference for the entire accelerometer. Four positioning lead pins 2 pass through the resonant circuit and are sintered to the mounting base 1, providing an installation reference for the upper isolation plate 17 and the lower isolation plate 4.

[0043] 2) The outer circle of the lower isolation plate 4 is bonded to the inner circle of the mounting base 1 by adhesive. The lower isolation plate 4 is etched with lower positioning holes 5 that are clearance-matched with the four positioning lead pins 2 of the mounting base 1. At the same time, the lower isolation plate 4 is etched with quartz mass pendulum mounting holes to provide installation space for the mass pendulum fixing boss 8;

[0044] 3) The quartz mass pendulum structure 7 has a mass pendulum fixing boss 8, which is engaged with the mounting holes of the upper isolation plate 17 and the lower isolation plate 4 via adhesive. The trapezoidal stress isolation area 10 of the quartz mass pendulum structure 7 passes through the four positioning lead posts 2 without interfering with each other;

[0045] 4) The gold wire lead of the lower resonant beam 16 is welded to the conductive gold film on the bottom surface of the quartz mass pendulum structure 7. The lower conductive gold film is connected to the upper conductive gold film through the gold film on the side, so that the lead signal of the lower resonant beam 16 is led to the upper surface and is on the same plane as the lead signal of the upper resonant beam 15. The signal of the upper resonant beam 15 is directly welded to the positioning lead post 2. The lead signal of the lower resonant beam 16 is welded to the positioning lead post 2 through the resonant beam positioning and the conductive gold film of the lower resonant beam, so that the output signals of the upper resonant beam 15 and the lower resonant beam 16 are transmitted to the resonant circuit;

[0046] 5) The inner circle of the upper isolation plate 17 is bonded to the outer circle of the quartz mass pendulum structure 7 by adhesive. The upper isolation plate 17 is etched with upper positioning holes 18 to fit the four positioning lead pins 2 of the mounting base 1. The upper isolation plate 17 is also etched with quartz mass pendulum mounting holes 19 to provide mounting space for the mass pendulum fixing boss 8.

[0047] 6) The housing 20 is fixedly connected to the mounting base 1 by laser welding.

[0048] The resonant circuit is placed in the mounting base, and the output signal of the resonant beam is introduced into the resonant circuit through the positioning lead column 2. After amplification by the resonant circuit, the four signal output columns 3 are connected to the resonant circuit to output the resonant beam output signal. The quartz mass pendulum structure 7 is designed with a mass pendulum fixing boss 8, an outer ring mounting frame 9, a trapezoidal stress isolation area 10, a mass pendulum tongue 11, a flexible support 12, a resonant beam vibration groove 13, and a resonant beam positioning and lower resonant beam conductive gold film 14; the mass pendulum fixing boss 8 and the outer ring mounting frame 9 complete the coordination with the upper and lower isolation plates; the trapezoidal stress isolation area 10 greatly reduces the temperature stress interference and improves the temperature characteristics and stability of the product; when an external acceleration is input, the mass pendulum tongue 11 is sensitive to the input acceleration and converts the input acceleration into the axial force of the resonant beam. The resonant beam is plated with three sections of positive and negative electrodes around it. Based on the piezoelectric effect, it vibrates under the excitation of the resonant circuit. The resonant beam vibration groove 13 provides a vibration space for the resonant beam. The resonant beam is in force-frequency coupling. When the external input acceleration changes, the vibration frequency of the resonant beam changes. The changed acceleration is in a certain proportional relationship with the changed frequency. The external input acceleration value is obtained by measuring the changed frequency. After the upper and lower resonant beams are mounted on the quartz mass pendulum structure 7, they form the sensitive chip structure. This sensitive chip structure mates with the lower isolation plate 4 through the first quartz mass pendulum mounting hole 6. Similarly, the upper isolation plate 17 mates with the sensitive chip structure through the second quartz mass pendulum mounting hole 19. Together, the upper and lower isolation plates and the sensitive chip structure form the watch movement structure, creating a primary seal. The outer casing and mounting base are laser welded to the mounting base, completing the secondary seal.

Claims

1. A two-stage sealed, low temperature coefficient all-quartz resonant accelerometer structure, comprising a mounting base (1), characterized in that: The mounting base (1) is connected to a lower isolation plate (4), a quartz mass pendulum structure (7) is mounted on the lower isolation plate (4), an upper isolation plate (17) is mounted on the quartz mass pendulum structure (7), the upper isolation plate (17), the quartz mass pendulum structure (7), and the lower isolation plate (4) are connected to the mounting base (1) via positioning lead pins (2), and a housing (20) provided on the outer side of the upper isolation plate (17) is connected to the mounting base (1).

2. The all-quartz resonant accelerometer structure according to claim 1, characterized in that: The mounting base (1) is made of 0Cr18Ni9Ti metal material, and the four positioning lead posts (2) and the four signal output posts (3) are respectively fixed to the mounting base (1) by sintering. The four positioning lead posts (2) are plated with a gold film, and the lead-out gold wire of the resonant beam is welded to the positioning lead posts (2), and the output signal of the resonant beam is led out to the resonant circuit.

3. The all-quartz resonant accelerometer structure according to claim 2, characterized in that: The lower isolation plate (4) is made of single crystal quartz glass and has four lower positioning holes (5) corresponding to the four positioning lead posts (2). The outer ring is coated with adhesive, and the mounting base (1) and the lower isolation plate (4) are matched through the adhesive, the positioning lead posts (2) and the lower positioning holes (5).

4. The all-quartz resonant accelerometer structure according to claim 1, characterized in that: The mass pendulum fixing boss (8) on the outer side of the quartz mass pendulum structure (7) corresponds to the first quartz mass pendulum mounting hole (6) on the lower isolation plate (4), and is precisely matched by adhesive; an upper resonant beam (15) and a lower resonant beam (16) are attached to the upper and lower sides of the quartz mass pendulum structure (7); the quartz mass pendulum structure (7) is plated with a resonant beam positioning and a lower resonant beam conductive gold film (14), and the resonant beam positioning and the lower resonant beam conductive gold film (14) are used to realize the resonant beam positioning and to simultaneously fix the lower resonant beam. The electrical signal of the resonant beam is led out through the conductive positive and negative electrodes; the outer ring mounting frame (9) outside the quartz mass pendulum structure (7) is respectively matched with the inner circular holes of the lower isolation plate (4) and the upper isolation plate (17); the trapezoidal stress isolation area (10) inside the quartz mass pendulum structure (7) isolates the temperature stress and reduces the temperature coefficient; the mass pendulum tongue (11) and the flexible support (12) inside the quartz mass pendulum structure (7) transmit the external input acceleration; and the resonant beam vibration groove (13) provides a vibration space for the resonant beam.

5. The all-quartz resonant accelerometer structure according to claim 1, characterized in that: The upper positioning hole (18) of the upper isolation plate (17) corresponds to each of the four positioning lead posts (2), and the second quartz mass pendulum mounting hole (19) of the upper isolation plate (17) corresponds to each of the mass pendulum fixing bosses (8) of the quartz mass pendulum structure (7), thereby achieving the coordination between the upper isolation plate (17) and the quartz mass pendulum structure (7).

6. The all-quartz resonant accelerometer structure according to claim 1, characterized in that: The lower isolation plate (4), the quartz mass pendulum structure (7), and the upper isolation plate (17) are precisely matched by sealant to achieve the first-level sealing of the watch movement; the housing (20) is made of 0Cr18Ni9Ti material, is consistent with the mounting base (1), and is laser welded with the mounting base (1) to achieve the second-level sealing.

7. The method for assembling a two-stage sealed, low temperature coefficient all-quartz resonant accelerometer structure according to claim 1, characterized in that: The following steps are involved: 1) placing the mounting base (1) on the mounting positioning fixture, and passing the four positioning lead pins (2) through the resonant circuit and sintering them on the mounting base (1); 2) The outer circle of the lower isolation plate (4) matches the inner circle of the mounting base (1), and the lower isolation plate (4) is etched with a lower positioning hole (5) that is clearance-matched with the four positioning lead pins (2) of the mounting base (1). At the same time, the lower isolation plate (4) is etched with a quartz mass pendulum mounting hole to provide mounting space for the mass pendulum fixing boss (8); 3) The quartz mass pendulum structure (7) has a mass pendulum fixing boss (8) that cooperates with the mounting holes of the upper isolation plate (17) and the lower isolation plate (4), and the trapezoidal stress isolation area (10) of the quartz mass pendulum structure (7) passes through four positioning lead posts; 4) The gold wire lead of the lower resonant beam (16) is welded to the conductive gold film on the bottom surface of the quartz mass pendulum structure (7). The lower conductive gold film is connected to the upper conductive gold film through the gold film on the side. The signal of the upper resonant beam (15) is directly welded to the positioning lead post (2). The lead signal of the lower resonant beam (16) is welded to the positioning lead post (2) through the resonant beam positioning and the conductive gold film of the lower resonant beam, so that the output signals of the upper resonant beam (15) and the lower resonant beam (16) are transmitted to the resonant circuit; 5) The inner circle of the upper isolation plate (17) is matched with the outer circle of the quartz mass pendulum structure (7), and the upper isolation plate (17) is etched with an upper positioning hole (18) to be clearance-matched with the four positioning lead pins (2) of the mounting base (1), and a second quartz mass pendulum mounting hole (19) is etched to provide mounting space for the mass pendulum fixing boss (8); 6) The housing (20) is fixedly connected to the mounting base (1) by laser welding.

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