Three-axis sensor chip packaging structure and method
By using a ceramic cubic packaging frame with orthogonal layout design, laser welding, and inert gas filling technology, combined with ASIC chip signal processing and cleaning components, the orthogonality error and stability problems of traditional triaxial sensors are solved, realizing a high-precision, low-power triaxial sensor package suitable for high dynamic environments.
Patent Information
- Application Number
- CN202511027276.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-24
- Publication Date
- 2025-11-07
AI Technical Summary
Traditional triaxial sensors suffer from problems such as large size, difficulty in orthogonality calibration, severe signal crosstalk, high manufacturing complexity, high cost, insufficient flexibility, difficulty in balancing mechanical strength and environmental isolation performance, low installation accuracy, sensitivity to humidity and temperature changes, poor long-term stability, increased power consumption and noise due to separation of signal processing circuits from sensing units, and difficulty in completely removing micron-sized contaminants.
The cubic packaging frame made of ceramic material and orthogonal layout design, combined with laser welding and inert gas filling technology, achieves spatial orthogonal integration of triaxial MEMS sensor units through precision manufacturing process. The ASIC chip integrates signal processing and compensation algorithms, and optical alignment system and gold wire bonding technology are used to ensure electrical connection. A dedicated cleaning component is used for pre-packaging cleanliness treatment, and dynamic compensation technology is used for calibration testing.
It achieves high precision and high reliability in small-volume triaxial sensor packaging, solves the problems of large orthogonality error and insufficient long-term stability, reduces power consumption and signal crosstalk, and is suitable for accurate measurement in high dynamic environments.
Smart Images
Figure CN120903428A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of sensor packaging, in particular to a three-axis sensor chip packaging structure and method. BACKGROUND
[0002] Traditional three-axis sensors usually adopt discrete MEMS chip combination or single-chip integration scheme, the former has problems such as large volume, difficulty in orthogonal calibration, and serious signal crosstalk, and the latter is limited by high process complexity, high cost and insufficient flexibility, and existing packaging technologies mostly use plastic or metal shells, which are difficult to balance mechanical strength and environmental isolation performance, and the installation precision of internal sensor units is limited by assembly process, resulting in large three-axis orthogonal error, in addition, conventional packaging structures are sensitive to humidity, temperature changes and mechanical vibration, and have poor long-term stability, the design of separating signal processing circuit and sensor unit also increases power consumption and noise, and the traditional method is difficult to completely remove micron-level pollutants in the cleaning link before packaging, which affects the welding quality and device reliability, therefore, a high-precision, high-reliability and easy-to-produce three-axis sensor packaging scheme is needed to solve the key technical problems of multi-axis integration, orthogonal calibration and environmental protection. SUMMARY
[0003] To this end, the present application provides a three-axis sensor chip packaging structure and method to solve the above problems.
[0004] The present application provides the following technical scheme: a three-axis sensor chip packaging structure, comprising a cubic packaging frame, a MEMS sensor unit is fixedly connected to the inner wall of the cubic packaging frame, a packaging material is filled in the opening of the cubic packaging frame, and a circuit substrate is fixedly connected to the bottom of the cubic packaging frame. The number of MEMS sensor units is three, three MEMS sensor units are fixed to the inner walls of the cubic packaging frame at three different positions, each MEMS sensor unit comprises a gyroscope chip MEMS, an ASIC chip is electrically connected to the output end of the gyroscope chip MEMS, the outer side of the gyroscope chip MEMS is fixedly connected to the inner wall of the cubic packaging frame, and the outer side of the ASIC chip is fixedly connected to the inner wall of the cubic packaging frame.
[0005] As a preferred scheme of the present application, the cubic packaging frame is a hollow right cubic structure, the included angle between each MEMS sensor unit is 90°, and the packaging material is used to package the cubic packaging frame and the MEMS sensor units into a cubic form.
[0006] As a preferred scheme of the present application, the material of the cubic packaging frame is ceramic, the cubic packaging frame is used to provide mechanical support and environmental isolation protection, the MEMS sensor unit is fixed on the inner side wall of the cubic packaging frame by welding, the packaging material is epoxy resin, the packaging material is used to protect the internal components from moisture, dust and mechanical impact, the outer surface of the cubic packaging frame is provided with electrically connected pins, the cubic packaging frame is connected with external circuit through the electrically connected pins, the ASIC chip is electrically connected with the gyroscope chip MEMS through gold wire bonding, and the ASIC chip integrates signal processing, data conversion and communication interface functions.
[0007] A three-axis sensor chip packaging method adopts any one of the three-axis sensor chip packaging structures, and comprises the following steps: S1, an internally hollowed right cubic packaging frame is processed, the frame is made of ceramic, and a positioning groove for fixing a sensor unit is formed on the inner wall of the frame; S2, three MEMS sensor units are fixed on three adjacent inner side walls of the cubic packaging frame respectively, and the space included angle between each MEMS sensor unit is ensured to be 90°; S3, a gyroscope chip MEMS and an ASIC chip are arranged in each MEMS sensor unit, the gyroscope chip MEMS is electrically connected with the ASIC chip, the signal pin of the gyroscope chip MEMS is connected to the corresponding ASIC chip through gold wire bonding, and data fusion of three-axis signals is realized through the integrated circuit of the ASIC chip; S4, packaging is performed by using a packaging material, calibration testing is performed on the packaged structure, the orthogonality and signal output precision of the three-axis sensor are verified, and it is ensured that the output signal of the three-axis sensor meets the preset precision requirement.
[0008] As a preferred scheme of the present application, when the MEMS sensor unit is fixed, a high-precision clamp or an optical alignment device is used to ensure the accuracy of the space included angle, the packaging material is formed through injection molding, mold pressing or vacuum sealing process, a sealing cover plate is covered on the opening end of the cubic packaging frame, the packaging is completed through airtight welding process, a sealed cavity is formed, and the cubic packaging frame is pretreated through cleaning components before packaging.
[0009] As a preferred scheme of the present application, the positioning groove in each inner wall is coated with heat-conducting glue, the gyroscope chip and the ASIC chip are attached to the positioning groove, the heat-conducting glue is solidified through a heat curing process, the sensitive axis direction of the three gyroscope chips is detected through an optical alignment instrument, it is ensured that the included angle is 90°±0.5°, and the fixing of the MEMS sensor unit is completed.
[0010] As a preferred scheme of the present application, the sealing cover plate is made of Kovar alloy material, the edge thereof is laser welded with the opening end of the cubic packaging frame to form an airtight package, and the cavity after packaging is filled with inert gas with a pressure of 0.8 atm.
[0011] As a preferred scheme of the present application, the calibration test comprises: placing the packaged sensor on a three-axis turntable, applying a known angular velocity in X, Y and Z directions respectively, collecting the output signals of each axis and calculating the orthogonality error and sensitivity coefficient by least square fitting, and writing the calibration parameters into the non-volatile memory of the ASIC chip and completing dynamic compensation.
[0012] As a preferred scheme of the present application, the cleaning assembly comprises a base, an outer cover mounted on the top of the base, a snap ring fixedly connected to the top of the base, the surface of the snap ring being in sliding connection with the inner wall of the outer cover, four installers fixedly connected to the top of the base, the installers being arranged in an annular array, a cover plate fixedly connected to the top of the outer cover, a water inlet pipe fixedly connected to the inner wall of the cover plate, a spiral flow guide plate fixedly connected to the inner wall of the water inlet pipe, a sealing rod fixedly connected to the inner wall of the spiral flow guide plate, an impeller rotatably connected to the bottom of the sealing rod, stirring blades fixedly connected to the surface of the impeller, the stirring blades being arranged in an annular array, and a water outlet hole penetrating through the top of the base.
[0013] Compared with the prior art, the present application has the following advantages: In the present application, the spatial orthogonal integration of the three-axis MEMS sensor unit is realized by adopting a cubic packaging frame made of ceramic material and an orthogonal layout design, and through a precision manufacturing process. The strict orthogonality of the three-axis sensitive directions is ensured by the high-precision positioning grooves pre-set on the inner wall of the ceramic frame. The protective cavity with excellent airtightness is formed by the Kovar alloy sealing cover plate welded by laser and the inert gas filling technology. The optical alignment system and gold wire bonding technology are used in the packaging process to ensure the reliability of electrical connection. The epoxy resin filling effectively resists mechanical impact and environmental interference. The ASIC chip integrates multi-axis signal processing and compensation algorithm, which significantly improves the signal consistency and anti-crosstalk ability. The special cleaning assembly ensures the cleanliness before packaging through turbulent flushing. The dynamic compensation technology is used in the calibration test link to optimize the performance in the whole temperature range. The overall scheme realizes the industrial-level environmental tolerance while maintaining a small size, and solves the problems of low space utilization, poor orthogonal precision and insufficient long-term stability of the traditional multi-chip solution. BRIEF DESCRIPTION OF DRAWINGS
[0014] Figure 1 It is a schematic diagram of the overall structure of the present application; Figure 2 It is a schematic diagram of the overall structure of the present application; Figure 1Internal structure schematic diagram in the application; Figure 3 Structure schematic diagram of the cleaning assembly in the application; Figure 4 Structure schematic diagram of the cleaning assembly in the application Figure 4 Structure sectional view of the cleaning assembly in the application; Figure 5 Structure sectional view of the cleaning assembly in the application Figure 4 Local structure sectional view of the cleaning assembly in the application; Figure 6 Flow chart of the three-axis sensor chip packaging method in the application.
[0015] In the figure: 1, cubic package frame; 2, gyroscope chip MEMS; 3, ASIC chip; 4, circuit substrate; 5, packaging material; 6, cover plate; 7, water inlet pipe; 8, base; 9, snap ring; 10, stirring blade; 11, sealing rod; 12, spiral guide plate; 13, impeller; 14, mount; 15, outer cover. DETAILED DESCRIPTION
[0016] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the application.
[0017] Please refer to Figures 1-6 The technical solutions provided by the application specifically include the following embodiments: Embodiment: A three-axis sensor chip packaging structure, comprising a cubic packaging frame 1, a MEMS sensor unit fixedly connected to the inner wall of the cubic packaging frame 1, a packaging material 5 filled in the opening of the cubic packaging frame 1, and a circuit substrate 4 fixedly connected to the bottom of the cubic packaging frame 1; the number of the MEMS sensor units is three, and the three MEMS sensor units are fixed to three different inner walls of the cubic packaging frame 1; each MEMS sensor unit comprises a gyroscope chip MEMS 2, the output end of the gyroscope chip MEMS 2 is electrically connected to an ASIC chip 3, the outer side of the gyroscope chip MEMS 2 is fixedly connected to the inner wall of the cubic packaging frame 1, and the outer side of the ASIC chip 3 is fixedly connected to the inner wall of the cubic packaging frame 1; the cubic packaging frame 1 is a hollow right cubic structure, the included angle between the spaces of each MEMS sensor unit is 90°, and the packaging material 5 is used to package the cubic packaging frame 1 and the MEMS sensor units into a cubic form; the material of the cubic packaging frame 1 is ceramic, the cubic packaging frame 1 is used to provide mechanical support and environmental isolation protection, the MEMS sensor units are fixed to the inner side walls of the cubic packaging frame 1 by welding, the packaging material 5 is epoxy resin, the packaging material 5 is used to protect the internal elements from the influence of moisture, dust and mechanical impact, the outer surface of the cubic packaging frame 1 is provided with electrically connected pins, the cubic packaging frame 1 is connected to an external circuit through the electrically connected pins, the ASIC chip 3 and the gyroscope chip MEMS 2 are electrically connected through gold wire bonding, and the ASIC chip 3 integrates signal processing, data conversion and communication interface functions. The three-axis sensor chip packaging structure adopts an orthogonal layout as a whole, adopts a cubic packaging frame 1 made of ceramic, and is provided with high-precision positioning grooves in the inner wall, so that the included angle of the three mounting positions is strictly kept at 90°. In the assembly process, the three MEMS sensor units are fixed to the adjacent inner walls by a precision mechanical arm cooperating with an optical alignment system. Each sensor unit comprises a gyroscope chip 2 and a signal processing ASIC chip 3, and the two are electrically connected through gold wire bonding. The ceramic material of the packaging frame not only provides excellent mechanical support, but also effectively isolates external environmental interference. After packaging is completed, the inside is filled with epoxy resin material to form a complete cubic structure, so as to ensure that the sensor units are not affected by moisture, dust and mechanical impact.
[0018] A three-axis sensor chip packaging method, which adopts a three-axis sensor chip packaging structure and comprises the following steps: S1, processing a hollow right cubic packaging frame, which is made of ceramic and is provided with positioning grooves in the inner wall for fixing sensor units; S2, fixing three MEMS sensor units to three adjacent inner side walls of the cubic packaging frame, so that the included angle between the spaces of each MEMS sensor unit is 90°. S3, setting a gyroscope chip MEMS and an ASIC chip in each MEMS sensor unit, electrically connecting the gyroscope chip MEMS and the ASIC chip, connecting the signal pins of the gyroscope chip MEMS to the corresponding ASIC chip through gold wire bonding, and realizing data fusion of three-axis signals through integrated circuits of the ASIC chip; S4, packaging using a packaging material, calibrating and testing the packaged structure, verifying the orthogonality and signal output accuracy of the three-axis sensor, and ensuring that the output signal of the three-axis sensor meets the preset accuracy requirement.
[0019] When fixing the MEMS sensor unit, a high-precision clamp or an optical alignment device is used to ensure the accuracy of the spatial angle, and the packaging material is formed by injection molding, molding or vacuum sealing process. A sealing cover plate is covered on the open end of the cubic packaging frame, and the packaging is completed by using airtight welding process to form a sealed cavity. The cubic packaging frame is pretreated by cleaning components before packaging; After the installation of the MEMS sensor unit is completed, the open end of the cubic frame is covered with a Kovar sealing cover plate, and the edge of the cover plate is tightly combined with the frame by laser welding process to form a completely sealed cavity. Before packaging, the cavity is vacuumed and filled with inert gas to reduce the risk of oxidation and improve long-term stability. This process not only ensures a clean environment for internal components, but also effectively suppresses the influence of air pressure fluctuations caused by temperature changes on sensor performance. The packaged structure is strictly tested for air tightness to ensure reliable performance in harsh environments.
[0020] Thermal conductive glue is coated in the positioning groove of each inner wall, and the gyroscope chip and the ASIC chip are attached in the positioning groove. The thermal conductive glue is solidified by thermal curing process. The optical alignment instrument is used to detect the sensitive axis direction of the three gyroscope chips to ensure that the included angle is 90°±0.5°. The fixation of the MEMS sensor unit is completed.
[0021] The sealing cover plate is made of Kovar alloy material, and the edge of the sealing cover plate is laser welded with the open end of the cubic packaging frame to form an airtight package. After packaging, the cavity is filled with inert gas, and the air pressure is 0.8 atm.
[0022] The calibration test includes: placing the packaged sensor on a three-axis turntable and applying known angular velocities in X, Y and Z directions respectively, collecting the output signals of each axis and calculating the orthogonality error and sensitivity coefficient by least squares fitting, and writing the calibration parameters into the non-volatile memory of the ASIC chip and completing dynamic compensation; Three gyroscopic chips detect the angular velocity signals of X, Y and Z axes respectively, and the corresponding ASIC chips are used for preliminary amplification and analog-to-digital conversion. The ASIC chip integrates signal conditioning, data conversion and communication interface functions, can process multi-axis data in real time, fuse and orthogonal compensate three-axis signals through internal algorithm, ensure the accuracy and consistency of output data, and significantly reduce the power consumption and signal crosstalk of traditional multi-chip scheme, while improving the overall response speed of the system, which is suitable for precise measurement in high dynamic environment. The assembled three-axis sensor is placed on a high-precision turntable, and a known angular velocity is applied to calibrate the sensitivity and zero offset of each axis. The least square method is used to fit and calculate the orthogonality error, and the calibration parameters are written into the non-volatile memory of the ASIC chip. The calibration process also includes temperature compensation test to ensure stable output of the sensor in the full temperature range. The final verification stage is through multi-position rotation test to confirm that the output accuracy of the three-axis signal meets the design requirements and meets the harsh conditions of actual application scenarios.
[0023] The cleaning assembly comprises a base 8, the top of the base 8 is provided with an outer cover 15, the top of the base 8 is fixedly connected with a clamping ring 9, the surface of the clamping ring 9 is slidably connected with the inner wall of the outer cover 15, the top of the base 8 is fixedly connected with a mounting device 14, the mounting device 14 is provided with four mounting devices 14 arranged in a ring array, the top of the outer cover 15 is fixedly connected with a cover plate 6, the inner wall of the cover plate 6 is fixedly connected with a water inlet pipe 7, the inner wall of the water inlet pipe 7 is fixedly connected with a spiral flow guide plate 12, the inner wall of the spiral flow guide plate 12 is fixedly connected with a sealing rod 11, the bottom of the sealing rod 11 is rotatably connected with an impeller 13, the surface of the impeller 13 is fixedly connected with stirring blades 10, the stirring blades 10 are provided with four stirring blades 10 arranged in a ring array, and the top of the base 8 is provided with a water outlet hole; A special cleaning assembly is used to pretreat the cubic packaging frame 1 to ensure that the inner wall is free of residual pollutants. During cleaning, the frame is mounted on the mounting device 14 to fix the frame. The water flow forms a turbulent flow through the spiral flow guide plate 12, drives the impeller 13 to rotate, and makes the stirring blades 10 generate high-speed vortex to realize comprehensive flushing of the inner surface of the frame. The water inlet flow is greater than the water outlet flow, forming a circulating flushing effect, effectively removing small particles and grease. The cleaned frame is dried to provide a clean environment for subsequent installation of the sensor unit, avoiding pollution affecting the packaging quality and sensor performance.
[0024] In the application, the overall three-axis sensor chip packaging structure adopts orthogonal layout, adopts a cubic packaging frame 1 of ceramic material, the inner wall is provided with a high-precision positioning groove, so that the space included angle of the three mounting positions is strictly kept at 90 degrees, in the assembly process, the three MEMS sensor units are fixed on the adjacent inner wall through the cooperation of the precision mechanical arm and the optical alignment system, each sensor unit includes a gyroscope chip 2 and a signal processing ASIC chip 3, and the two are electrically connected through gold wire bonding, the ceramic material of the packaging frame not only provides excellent mechanical support, but also effectively isolates external environmental interference, after the packaging is completed, the inside is filled with epoxy resin material, forming a complete cubic structure, ensuring that the sensor unit is not affected by moisture, dust and mechanical impact, after the installation of the MEMS sensor unit is completed, a Kovar alloy sealing cover plate covers the open end of the cubic frame, the edge of the cover plate is tightly combined with the frame through a laser welding process, forming a completely sealed cavity, before packaging, the cavity is evacuated and filled with inert gas to reduce the risk of oxidation and improve long-term stability, this process not only ensures a clean environment for internal components, but also effectively suppresses the influence of air pressure fluctuations caused by temperature changes on sensor performance, the packaged structure is strictly tested for air tightness to ensure that it can still maintain reliable performance in harsh environments, the three gyroscope chips detect the angular velocity signals of the X, Y and Z axes respectively, and the corresponding ASIC chips perform preliminary amplification and analog-to-digital conversion, the ASIC chip integrates signal conditioning, data conversion and communication interface functions, can process multi-axis data in real time, fuse and orthogonal compensate three-axis signals through internal algorithms, ensure the accuracy and consistency of output data, this design significantly reduces the power consumption and signal crosstalk of traditional multi-chip solutions, while improving the overall response speed of the system, suitable for precise measurement in high dynamic environments, place the assembled three-axis sensor on a high-precision turntable, apply a known angular velocity to calibrate the sensitivity and zero offset of each axis, calculate the orthogonality error by least squares fitting, and write the calibration parameters into the non-volatile memory of the ASIC chip, the calibration process also includes temperature compensation testing to ensure stable output of the sensor within the full temperature range, the final verification stage confirms that the output accuracy of the three-axis signal meets the design requirements through multi-position rotation testing, meets the harsh conditions of actual application scenarios, a special cleaning assembly is used to pretreat the cubic packaging frame 1 to ensure that the inner wall is free of residual contaminants, during cleaning, the frame is installed on the mount 14 to fix the frame, the water flow forms a turbulent flow through the spiral guide plate 12, driving the impeller 13 to rotate, causing the stirring blade 10 to generate a high-speed vortex, achieving comprehensive flushing of the inner surface of the frame, the water inflow is greater than the water outflow, forming a circulating flushing effect, effectively removing small particles and grease, the cleaned frame is dried to provide a clean environment for subsequent installation of sensor units, avoiding contamination affecting packaging quality and sensor performance, the cleaning assembly is simple in structure and does not require power driving, facilitating use.
[0025] While embodiments of the present application have been shown and described, it is to be understood that the embodiments described are merely divergences of the principles and spirit of the present application and that numerous modifications, changes, substitutions, and alterations can be made thereto without departing from the principles and spirit of the present application.
Claims
1. A tri-axial sensor chip package structure, characterized by: The application relates to a three-axis MEMS sensor, which comprises a cubic packaging frame (1), the inner wall of the cubic packaging frame (1) is fixedly connected with MEMS sensor units, the opening of the cubic packaging frame (1) is filled with a packaging material (5), and the bottom of the cubic packaging frame (1) is fixedly connected with a circuit substrate (4). The number of the MEMS sensor units is three, the three MEMS sensor units are fixed on three different inner walls of the cubic packaging frame (1), each MEMS sensor unit comprises a gyroscope chip MEMS (2), the output end of the gyroscope chip MEMS (2) is electrically connected with an ASIC chip (3), the outer side of the gyroscope chip MEMS (2) is fixedly connected with the inner wall of the cubic packaging frame (1), and the outer side of the ASIC chip (3) is fixedly connected with the inner wall of the cubic packaging frame (1).
2. The triaxial sensor chip package structure of claim 1, wherein: The cubic packaging frame (1) is a hollowed-out regular cubic structure, the included angle between the spaces of the MEMS sensor units is 90 degrees, and the packaging material (5) is used for packaging the cubic packaging frame (1) and the MEMS sensor units into a cubic form.
3. The triaxial sensor chip package structure of claim 1, wherein: The material of the cubic packaging frame (1) is ceramic, the cubic packaging frame (1) is used for providing mechanical support and environmental isolation protection, the MEMS sensor units are fixed on the inner side walls of the cubic packaging frame (1) through welding, the packaging material (5) is epoxy resin, the packaging material (5) is used for protecting internal elements from moisture, dust and mechanical impact, the outer surface of the cubic packaging frame (1) is provided with electrically connected pins, the cubic packaging frame (1) is connected with external circuits through the electrically connected pins, the ASIC chip (3) and the gyroscope chip MEMS (2) are electrically connected through gold wire bonding, and the ASIC chip (3) integrates signal processing, data conversion and communication interface functions.
4. A method for packaging a triaxial sensor chip, using the triaxial sensor chip packaging structure of any one of claims 1-3, characterized in that: The application further discloses a three-axis MEMS sensor packaging method, which comprises the following steps: S1, a hollowed-out regular cubic packaging frame is processed, the frame is made of ceramic, and positioning grooves for fixing sensor units are formed in the inner wall of the frame; S2, three MEMS sensor units are fixed on three adjacent inner side walls of the cubic packaging frame, and the included angle between the spaces of the MEMS sensor units is ensured to be 90 degrees; S3, a gyroscope chip MEMS and an ASIC chip are arranged in each MEMS sensor unit, the gyroscope chip MEMS and the ASIC chip are electrically connected, the signal pins of the gyroscope chip MEMS are connected to the corresponding ASIC chip through gold wire bonding, and the integrated circuit of the ASIC chip is used for realizing data fusion of three-axis signals; S4, a packaging material is used for packaging, and the packaged structure is calibrated and tested to verify the orthogonality and signal output precision of the three-axis sensor, so that the output signal of the three-axis sensor meets the preset precision requirement.
5. The method of claim 4, wherein: When fixing the MEMS sensor unit, high-precision clamps or optical alignment devices are used to ensure the accuracy of the spatial angle. The packaging material is formed by injection molding, molding or vacuum sealing process. The sealing cover plate covers the open end of the cubic packaging frame. The air-tight welding process is used to complete the packaging and form a sealed cavity. The cubic packaging frame is pretreated by the cleaning assembly before packaging.
6. The method of claim 4, wherein: The heat-conducting glue is coated in the positioning groove of each inner wall. The gyroscope chip and the ASIC chip are attached to the positioning groove. The heat-conducting glue is solidified by the heat curing process. The optical alignment instrument is used to detect the sensitive axis direction of the three gyroscope chips to ensure that the included angle is 90°±0.5°. The fixing of the MEMS sensor unit is completed.
7. The method of claim 5, wherein: The sealing cover plate is made of Kovar alloy material. The edge of the sealing cover plate is laser welded with the open end of the cubic packaging frame to form an air-tight package. After packaging, the cavity is filled with inert gas with a pressure of 0.8 atm.
8. The method of claim 4, wherein: The calibration test includes placing the packaged sensor on a three-axis turntable and applying known angular velocities in X, Y and Z directions respectively, collecting the output signals of each axis and calculating the orthogonality error and sensitivity coefficient by least squares fitting, writing the calibration parameters into the non-volatile memory of the ASIC chip and completing the dynamic compensation.
9. The method of claim 4, wherein: The cleaning assembly comprises a base (8), an outer cover (15) mounted on the top of the base (8), a snap ring (9) fixedly connected to the top of the base (8), the surface of the snap ring (9) being in sliding connection with the inner wall of the outer cover (15), an installation device (14) fixedly connected to the top of the base (8), the number of the installation device (14) being four, the four installation devices (14) being arranged in a ring array, a cover plate (6) fixedly connected to the top of the outer cover (15), a water inlet pipe (7) fixedly connected to the inner wall of the cover plate (6), a spiral guide plate (12) fixedly connected to the inner wall of the water inlet pipe (7), a sealing rod (11) fixedly connected to the inner wall of the spiral guide plate (12), a impeller (13) rotatably connected to the bottom of the sealing rod (11), a stirring blade (10) fixedly connected to the surface of the impeller (13), the number of the stirring blade (10) being four, the four stirring blades (10) being arranged in a ring array, and a water outlet hole (16) penetrating through the top of the base (8).