CN105021846A - Six-axis integrated miniature acceleration sensor and manufacturing method therefor - Google Patents

Abstract

The invention discloses a six-axis integrated micro-acceleration sensor and a manufacturing method thereof, comprising upper and lower cover plates and a sensing chip connected together by bonding. The sensing chip includes four beams drawn from the diagonal of the fixed outer frame and connected to the middle "island", so that the "island" in the middle of the outer frame, the beams on the diagonal of the outer frame, and the outer frame form a whole— A fixed frame, each inertial sensing unit is composed of an inertial mass block, a structural support beam, and a sensitive micro-beam, each of the inertial mass blocks is trapezoidal, and the middle part of the upper bottom edge has a structural support beam extending to the lower bottom edge ; On both sides of the structural support beam, there are sensitive micro-beams connecting the upper bottom edge of the trapezoidal inertial mass block with the "island" in the middle of the fixed frame. Due to the small structure of the sensitive microbeam, the main stress will be concentrated when the sensitive chip is loaded, and it is easy to form a simple stress state of direct tension and direct compression, which is very conducive to decoupling between axes. The invention has a simple and compact structure and is easy to process.

Description

A six-axis integrated micro-acceleration sensor and its manufacturing method

technical field

The invention relates to the field of silicon micro-accelerometers, in particular to a piezoresistive six-axis high-range micro-accelerometer and a manufacturing method thereof.

Background technique

An acceleration sensor refers to a sensor that can measure the acceleration of an object's motion. Sensitivity, linearity, inter-axis coupling, response speed, response frequency bandwidth, stability, etc. are its main performance indicators. The micro-accelerometer is a kind of acceleration sensor and is an important part of the newly developed micro-electromechanical system (MEMS). With the development of the semiconductor industry, especially the development of MEMS technology, more and more high-performance, low-energy Micro-acceleration sensors with low power consumption and low price are gradually applied to all walks of life, constantly changing the way people live and work. As a special inertial measurement device, the high-range acceleration sensor is mainly used in military and aviation fields. With the development of penetrating weapon systems and the in-depth study of explosive shock phenomena in recent years, people have gradually improved the performance of high-range acceleration sensors—the sensors are required to have a large range, large response bandwidth, and high natural frequency in order to be able to accurately , Quickly respond to the measured acceleration signal.

At present, the high-range acceleration sensors used in the research of penetration weapons at home and abroad are basically single-axis, and even if there are multiple axes, it is a simple combination of multiple single-axis, which is not only large in size, but also introduces installation errors. Patent CN 101692099 reports a piezoresistive dual-axis accelerometer with zero drift compensation. Although it solves the problem of piezoresistive temperature drift and has a high natural frequency, it is a combination of two uniaxial sensitive elements , and can only measure motion in two directions, and four motions in the six degrees of freedom in the object space cannot be measured, which cannot meet the requirements of all-round measurement and precise control for research on penetrating weapons.

Contents of the invention

The object of the present invention is to overcome the above-mentioned deficiencies in the prior art, and provide a six-axis integrated high-range micro-acceleration sensor and a manufacturing method thereof. Aiming at the problems of the existing high-g micro-accelerometer, the invention has a simple and compact structure, is easy to process and produce in batches, has a wide frequency range, a wide application range, and small coupling between axes.

In order to solve the above technical problems, the present invention adopts the following technical solutions.

A six-axis integrated high-range micro-acceleration sensor, which includes three parts: a sensitive chip connected together by bonding, an upper cover and a lower cover. The sensitive chip is composed of four sensing units, each sensor The sensing unit includes a structural support beam, a sensitive microbeam, an inertial mass block and a fixed frame, and each inertial mass block is connected to the middle island part of the fixed frame by a structural support beam and two sensitive microbeams to form a cantilever beam-mass In the block system, the two sensitive micro-beams are distributed symmetrically around the structural support beam, connecting the mass block and the middle island of the fixed frame, and each sensitive micro-beam has a doped sensitive resistor to form a Wheatstone bridge Sensing and decoupling between six-axis motion.

The fixed frame is composed of a fixed outer frame, a diagonal line of the outer frame, and an intermediate island; the diagonal line of the outer frame is in the middle, and the fixed outer frame is connected with the intermediate island, and the dimensions in the height direction are consistent; the intermediate island is the middle of the fixed frame. square column.

The inertial mass block is a trapezoidal column as a whole; the middle island of the fixed frame is the middle structure of the fixed frame, which is connected to the outer frame of the fixed frame through the diagonal line of the outer frame of the fixed frame, and is connected with the inertial mass through the structural support beam, the sensitive micro-beam The blocks are connected.

Eight compensating resistors are arranged on the fixed frame, and the compensating resistors are connected in parallel and in series with sensitive resistors to form 6 groups of Wheatstone bridges.

The length direction of the structural support beam is perpendicular to the upper and lower bottom edges of the inertial mass, and is located in the middle of the trapezoidal inertial mass, connects the middle island structure of the fixed frame and the trapezoidal inertial mass, and extends close to the lower bottom of the trapezoidal mass , the thickness of the structural support beam is the same as that of the inertial mass.

A method for manufacturing a six-axis integrated high-range micro-acceleration sensor,

1) Select N-type SOI silicon wafers, the thickness of the structural layer silicon is 10±1 μm, the thickness of the intermediate silicon dioxide isolation layer is 1-1.5 μm, and the thickness of the substrate layer silicon is 500 μm. After cleaning the surface of the silicon wafer, use the method of thermal oxidation on the , prepare a layer of 200 ~ 300nm SiO ₂ film below;

2) Lithograph the front side of the silicon wafer, then remove the exposed SiO ₂ with the hydrofluoric acid buffer BOE solution, and perform B-diffusion with the removed SiO ₂ as the window to form doped resistors: sensitive resistors, reference resistors;

3) Hydrofluoric acid buffer solution BOE washes away the upper surface layer SiO2, and then proceeds to thin-layer silicon oxide wafer, repeating step 2), the difference is that the ohmic contact area is made by heavily doping boron B;

4) Metallization; lithography on the front side of the silicon wafer, and prepare gold wires by sputtering-lift-off method; then, heat to 363±5°C and keep for 20-30min to form a stable local gold-silicon two-phase;

5) Front beam shape etching: Front photolithography, sputtering-stripping method to prepare patterned aluminum masking film, and then inductively coupled plasma etching ICP to etch out the shape of structural support beams and sensitive micro-beam masses, with a thickness of Thickness 10±1μm;

6) Photolithography on the back of the silicon wafer, 20% to 22% by mass fraction of tetramethylammonium hydroxide wet etching in a water bath at 85 to 90°C to form the active area of the silicon mass block;

7) Photolithography on the back of the silicon wafer, sputtering-stripping method to prepare a patterned aluminum film, and then reactive plasma etching RIE to etch out the inertial mass, and the etching thickness is the thickness of the silicon layer of the substrate;

8) Hydrofluoric acid buffer solution BOE corrodes the beam structure at the silicon wafer 1-1.5 μm SiO ₂ isolation layer to release the beam structure;

9) One side of the upper cover is photo-etched, and the upward active area of the mass block is etched with hydrofluoric acid buffer solution BOE, and the height of the active area is also the height after considering the damping characteristics;

10) The silicon wafer is sealed and connected with the upper cover plate and the lower cover plate by anodic bonding to make a glass-silicon wafer-glass sandwich structure;

11) Device package:

a. Use a mechanical dicing machine to scribe according to the dicing lane to make a sensitive accelerometer chip; b. Paste the above-mentioned chip into the ceramic square shell for packaging with AB glue; c. Use a gold wire ball welding machine to connect the fine gold wire and The pads on the sensitive chip are bonded one by one; d. Install the ceramic shell with a sealed shell cap and seal it with AB glue.

The materials of the upper cover and the lower cover are American Corning 7740 glass or German Schott BF33 glass for anodic bonding.

Compared with the prior art, the present invention has the advantages of:

1) The structure, process and readout circuit of the present invention are very simple. Through the simple, symmetrical and ingeniously designed sensitive unit, and the corresponding Wheatstone bridge as the readout circuit, the full decoupling of the acceleration of the six axial degrees of freedom in space can be realized, and the theoretical analysis of the coupling degree between axes is zero.

2) The present invention uses SOI silicon wafers to make sensors, so that the thickness and size of the microbeams can be precisely controlled. In addition, due to the insulation and heat insulation characteristics of SOI silicon wafers, the sensors produced by this process also have low environmental noise and good high temperature resistance.

3) The present invention utilizes a structural support beam with large rigidity with the same thickness as the mass block to make the natural frequency of the entire chip of the preferred size > 18KHz, so that it has a very wide frequency band and is widely applicable; in addition, it also enables the sensor to operate in a high range Under the action, it can still work linearly and normally, and its z-axis and x/y-axis axis acceleration ranges reach 100,000g _n and 10,000g _n respectively, where g _n is the unit gravity acceleration value.

4) All the doped resistors made on the sensitive chip of the present invention, including sensitive resistors and reference resistors, are made by the same process, with high similarity in physical properties, better temperature compensation performance, and smaller zero point drift.

5) The present invention rationally designs the movable gap of the mass block, and adopts bonding and packaging under certain vacuum conditions to obtain a damping ratio of about 0.7. In addition, the sensor has a higher natural frequency, so that the sensor has better dynamic performance and larger Q value.

The preparation method of the invention has the characteristics of simple process, convenient operation, high processing efficiency, good reliability and easy batch production.

Description of drawings

Fig. 1 is the overall structural representation of the present invention;

Fig. 2 is the structural representation of the acceleration sensitive chip of the present invention;

Fig. 3 is a layout diagram of sensitive resistor and reference resistor in the present invention,

Fig. 4 is a schematic diagram of decoupling in the present invention:

Figure (a) is a simplified force deformation diagram of the sensitive chip when the z-axis linear acceleration Az is applied;

Figure (b) is a simplified force deformation diagram of the sensitive chip when the y-axis linear acceleration Ay is applied;

Figure (c) is a simplified force deformation diagram of the sensitive chip when the x-axis linear acceleration Ax is loaded;

Figure (d) is a simplified force deformation diagram of the sensitive chip when the z-axis angular acceleration Ez is loaded;

Figure (e) is a simplified force deformation diagram of the sensitive chip when the x-axis angular acceleration Ex is applied;

Figure (f) is a simplified force deformation diagram of the sensitive chip when the y-axis angular acceleration Ey is loaded;

The g table is the six-axis acceleration/angular acceleration sensing and decoupling table;

Fig. 5 is a schematic diagram of decoupling circuit in the present invention:

Figure (a) is a decoupling sensing circuit diagram of x-axis and y-axis axial linear acceleration and angular acceleration;

Figure (b) is a detailed circuit diagram of z-axis linear acceleration decoupling sensing,

Figure (c) is the overall circuit diagram of z-axis linear acceleration decoupling sensing;

Figures (b) and (c) together form a z-axis linear acceleration decoupling sensing circuit diagram,

Figure (d) is a detailed circuit diagram of z-axis decoupling sensing,

Figure (e) is the overall circuit diagram of z-axis decoupling sensing.

Figures (d) and (e) together form a z-axis angular acceleration decoupling sensing circuit diagram,

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings.

1. Overall structure:

As shown in Fig. 1, Fig. 2 and Fig. 3, it includes a sensitive chip 3, an upper cover plate 1 and a lower cover plate 2 connected together by bonding; the sensitive chip 3 is composed of four sensing units, each Each sensing unit comprises a structural support beam 4, a sensitive microbeam 5, an inertial mass 6 and a fixed frame 7; each of the inertial mass 6 consists of a structural support beam 4, two sensitive microbeams 5 and a fixed frame 7 The middle islands are partially connected to form a cantilever-mass system; the two microbeams 5 are symmetrically distributed between the mass 6 and the middle island of the fixed frame 7 with the structural support beam 4, and each sensitive microbeam 5 Each has a doped sensitive resistor 9, and 8 doped reference resistors 8 are evenly distributed on the outer frame of the fixed frame to form a number of Wheatstone bridges together with the sensitive resistors for sensing between six-axis movements. Measurement and decoupling, see Figure 5. The structural support beam 4 has relatively high rigidity, which is used to increase the rigidity of the overall sensing structure, thereby increasing the natural frequency, working bandwidth and response speed. The structural support beam 4, the sensitive microbeam 5 and the inertial mass 6 are all structures; the sensitive resistor 9 and the reference resistor 8 are semiconductor-doped resistors made by light boron doping process. In Figure 3, the two sensitive resistors in each inertial sensing unit are distributed on the side of the sensitive micro-beam away from the support beam of the intermediate structure; in the beam length direction, the sensitive resistors are distributed near the inertial mass or near the middle of the fixed frame" One side of the "island" structure; the reference resistors are evenly distributed around the four right angles of the outer frame of the fixed frame.

As shown in FIG. 3 , the present invention designs a total of 16 doping resistors, including 8 sensitive resistors 9 and 8 reference resistors 8 . The 16 doped resistors are all produced in the same process to ensure uniformity; the resistors are in the form of a straight line, and the composite form is used to increase the sensitivity as much as possible and reduce the coupling degree.

The size of the six-axis integrated high-range micro-acceleration sensor is: 1) The overall size is: length*width*height=3.4*3.4*0.5mm ³ ; the size of the sensitive micro-beam is: length*width*height=*0.04*0.04 *0.01mm ³ ; Structural support beam size: length * width * height = 1.04*0.06*0.49mm ³ ; The volume of a single inertial mass is: equivalent bottom area * height = ((2.42+0.34)*1.04/2- 1.04*0.16)*0.49mm ³ ;

2. Six-axis acceleration decoupling.

As shown in Figure 3, Figure 4 and Figure 5, when the linear acceleration Az is loaded along the Z axis in the positive direction, the four mass blocks remain still due to inertia, and the fixed frame is consistent with the external acceleration. At this time, all sensitive resistors The state is in tension. As shown in Figure 4, a.; when the linear acceleration Ay is loaded in the positive direction along the y-axis, since the thickness of the structural support beam 4 is the same as that of the inertial mass 6, the stiffness is relatively large and it is in the middle of it, so the four sensitive beams parallel to the x-axis Microbeams are almost stress-free. Only the four microbeams perpendicular to the x-axis are stressed due to deformation, and the resistors R1.1 and R3.1 are under pressure, and the resistors R1.2 and R3.2 are under tension, as shown in Figure 4, b.; when Load the linear acceleration Ax in the positive direction along the x-axis. Similarly, the mass block 6 remains stationary due to inertia, and only the resistors R2.1 and R4.1 are pulled, and the resistors R2.2 and R4.2 are pressed, as shown in Figure 4 , c. As shown; When the angular acceleration Ez is applied positively along the z-axis, all sensitive micro-beams 5 will bend on the xoy plane, resulting in: resistance R1.1, resistance R4.1, resistance R2.2, resistance R3.2 Under pressure, resistance R1.2, resistance R4.2, resistance R2.1, resistance R3.1 are pulled, as shown in Figure 4, d. As shown; when the angular acceleration Ex is positively loaded along the x-axis, due to the symmetry of the structure, the microbeams parallel to the x-axis have almost no stress induction, while the microbeams perpendicular to the x-axis show one side tension: resistance R4.1, resistor R4.2, the other side pressure resistor R2.1, resistor R2.2, as shown in Figure 4, e.; when the angular acceleration Ey is loaded in the positive direction along the y-axis, similarly, the resistor R1 .1. The resistor R1.2 is pulled, the resistors R3.1 and R3.2 are pressed, and the rest are basically not stressed, as shown in Figure 4, f.

In summary, the stress at the sensitive resistor 9 on the sensitive micro-beam 5 after six-axis acceleration loading can be summarized as shown in Fig. 4, g. decoupling table. Its characteristics are: corresponding to the loading of Ax, Ay, and Ez, the stress states at the sensitive resistors of the two sensitive microbeams of the same mass block are the same in magnitude and opposite in direction. And corresponding to the loading of Ax and Ay, the stress state of the microbeam corresponds to the serial number "tidy", such as the stress state of the resistance R1.1 and the resistance R3.1 and the resistance R2.1 and the resistance R4.1 are consistent. And corresponding to Ez loading, the stress state of resistance R1.1 and resistance R3.2 and resistance R4.1 and resistance R2.2 are the same; corresponding to AZ, Ex, Ey loading, two sensitive microbeams of the same mass are sensitive The stress states at the resistors are exactly the same; and when Ex and Ey are loaded, the sum of all sensitive resistor stress vectors must be zero when other errors are ignored, but it is not zero when Az is loaded.

According to the above characteristics, the designed decoupling circuit diagram is shown in Figure 5. In the Ay readout bridge, the resistor R1.1 and the resistor R3.1 and the resistor R1.2 and the resistor R3.2 are opposite arms, and these two pairs are mutually Adjacent arm; in Ax readout bridge, resistance R2.1 and resistance R4.1 and resistance R2.2 and resistance R4.2 are opposite arms, and these two pairs are adjacent arms to each other; in Ey readout bridge, resistance R1.1 and resistor R1.2 and resistor R3.1 and resistor R3.2 are opposite arms, and these two pairs are adjacent arms to each other; in the Az readout bridge, resistor R1.1 and resistor R1.2, resistor R2 .1 and resistor R2.2, resistor R3.1 and resistor R3.2, resistor R4.1 and resistor R4.2 are opposite arms, and 8 reference resistors 8 are added to form 4 Wheatstone half-bridges respectively. Output Vout-Az1, Vout-Az2, Vout-Az3, Vout-Az4 respectively. Finally, by connecting the outputs of the four half-bridges in series, it is used as the z-axis linear acceleration response output; in the Ez readout bridge, the resistor R1.1 and the resistor R3.2 and the resistor R1.2 and the resistor R3.1 are pairs, Output Vout-Ez1, resistor R2.1 and resistor R4.2 and resistor R2.2 and resistor R4.1 are a pair, output Vout-Ez2, and connect the outputs of the two full bridges in series as the z-axis angular acceleration response output.

3. The manufacturing method of a six-axis integrated high-range micro-acceleration sensor of the present invention is:

1) Select N-type SOI silicon wafers, the thickness of the structural layer silicon is 10±1 μm, the thickness of the intermediate silicon dioxide isolation layer is 1-1.5 μm, and the thickness of the substrate layer silicon is 500 μm. After cleaning the surface of the silicon wafer, use the method of thermal oxidation on the , prepare a layer of 200 ~ 300nm SiO ₂ film below;

2) Lithograph the front side of the silicon wafer, then remove the exposed SiO ₂ with the hydrofluoric acid buffer BOE solution, and perform B-diffusion with the SiO ₂ removed as the window to form doped resistors: sensitive resistor 9, reference resistor 10;

3) Hydrofluoric acid buffer solution BOE washes away the upper surface layer SiO2, and then proceeds to thin-layer silicon oxide wafer, repeating step 2), the difference is that heavily doped boron (B) is used to make the ohmic contact area;

4) Metallization; lithography on the front side of the silicon wafer, and prepare gold wires by sputtering-lift-off method; then, heat to 363±5°C and keep for 20-30min to form a stable local gold-silicon two-phase;

5) Front beam shape etching: front photolithography, sputtering-lift-off method to prepare patterned aluminum masking film, and then inductively coupled plasma etching (ICP) to etch out the shape of structural support beam 4 and sensitive microbeam 5 mass block 6 , with a thickness of 10±1 μm for the device layer;

6) Photolithography on the back of the silicon wafer, 20% to 22% by mass fraction of tetramethylammonium hydroxide wet etching in a water bath at 85 to 90°C to form the active area of the silicon mass block,

7) Photolithography on the back of the silicon wafer, sputtering-stripping method to prepare a patterned aluminum film, and then reactive plasma etching (RIE) to etch out the inertial mass 6, and the etching thickness is the thickness of the silicon layer of the substrate;

8) Hydrofluoric acid buffer solution BOE corrodes the beam structure at the silicon wafer 1-1.5 μm SiO ₂ isolation layer to release the beam structure;

9) One side of the upper cover is photo-etched, and the upward active area of the mass block is etched with hydrofluoric acid buffer solution BOE, and the height of the active area is also the height after considering the damping characteristics;

10) The silicon chip is sealed and connected with the upper cover plate 1 and the lower cover plate 2 by anodic bonding, so as to make a glass-silicon chip-glass sandwich structure;

11) Device package:

a. Use a mechanical dicing machine to scribe according to the dicing lane to make a sensitive accelerometer chip; b. Paste the above-mentioned chip into the ceramic square shell for packaging with AB glue; c. Use a gold wire ball welding machine to connect the fine gold wire and The pads on the sensitive chip are bonded one by one; d. Install the ceramic shell with a sealed shell cap and seal it with AB glue.

Claims (7)

1. A six-axis integrated micro-acceleration sensor is characterized in that: it includes three parts of a sensitive chip (3), an upper cover plate (1) and a lower cover plate (2) connected together by bonding, and the sensitive chip (3) is composed of four sensing units, each sensing unit includes a structural support beam (4), a sensitive microbeam (5), an inertial mass (6) and a fixed frame (7), and each inertial The quality block (6) is connected to the middle island part of the fixed frame (7) by a structural support beam (4) and two sensitive microbeams (5) to form a cantilever beam-mass system, and the two sensitive microbeams ( 5) distributed symmetrically around the center of the structural support beam (4), connecting between the mass block (6) and the middle island of the fixed frame (7), each sensitive microbeam (5) has a doped sensitive resistor ( 9) It is used to form a Wheatstone bridge for sensing and decoupling between six-axis motions. 2. A six-axis integrated micro-acceleration sensor according to claim 1, characterized in that: the fixed frame (7) is composed of a fixed outer frame, a diagonal line of the outer frame, and a middle island; the diagonal line of the outer frame is at In the middle, the fixed outer frame is connected with the middle island, and the dimensions in the height direction are consistent; the middle island is a square column in the middle of the fixed frame. 3. A six-axis integrated micro-acceleration sensor according to claim 1, characterized in that: the inertial mass (6) is a trapezoidal column as a whole; the middle island of the fixed frame (7) is a fixed frame (7) The intermediate structure is connected to the outer frame of the fixed frame (7) through the diagonal line of the outer frame of the fixed frame (7), and is connected to the inertial mass (6) through the structural support beam (4) and the sensitive microbeam (5). 4. A six-axis integrated micro-acceleration sensor according to claim 1, characterized in that: the fixed frame (7) is provided with eight compensation resistors (8), and the compensation resistors (8) pass through and sensitive The resistors (9) are connected in parallel and in series to form 6 groups of Wheatstone bridges. 5. A six-axis integrated micro-acceleration sensor according to claim 1, characterized in that: the length direction of the structural support beam (4) is perpendicular to the upper and lower bottom edges of the inertial mass (6), and is located in the trapezoidal In the middle of the inertial mass (6), connect the middle island structure of the fixed frame (7) and the trapezoidal inertial mass (6), and extend close to the bottom edge of the trapezoidal mass (6), the structure supports the beam (4) The thickness is the same as the inertial mass block (6). 6. A method for manufacturing a six-axis integrated micro-acceleration sensor, characterized in that: 1) Select N-type SOI silicon wafers, the thickness of the structural layer silicon is 10±1 μm, the thickness of the intermediate silicon dioxide isolation layer is 1-1.5 μm, and the thickness of the substrate layer silicon is 500 μm. After cleaning the surface of the silicon wafer, use the method of thermal oxidation on the , prepare a layer of 200 ~ 300nm SiO ₂ thin film below; 2) Lithograph the front side of the silicon wafer, and then remove the exposed SiO ₂ with the hydrofluoric acid buffer BOE solution, and perform B-diffusion to form a doped resistor with the SiO ₂ removed as the window: sensitive resistor (9), reference resistor (10 ); 3) Hydrofluoric acid buffer solution BOE washes away the upper surface layer SiO2, and then proceeds to thin-layer silicon oxide wafer, repeating step 2), the difference is that the ohmic contact area is made by heavily doping boron B; 4) Metallization; lithography on the front side of the silicon wafer, and prepare gold wires by sputtering-lift-off method; then, heat to 363±5°C and keep for 20-30min to form a stable local gold-silicon two-phase; 5) Front beam shape etching: Front photolithography, sputtering-lift-off method to prepare patterned aluminum masking film, and then inductively coupled plasma etching ICP to etch out structural support beam (4), sensitive microbeam (5) mass block ( 6) The shape of the device layer is 10±1 μm in thickness; 6) Photolithography on the back of the silicon wafer, 20% to 22% by mass fraction of tetramethylammonium hydroxide wet etching in a water bath at 85 to 90°C to form the active area of the silicon mass block; 7) Photolithography on the back of the silicon wafer, sputtering-stripping method to prepare a patterned aluminum film, and then reactive plasma etching (RIE) to etch out the inertial mass (6), and the etching thickness is the thickness of the substrate silicon layer; 8) Hydrofluoric acid buffer solution BOE corrodes the beam structure at the silicon wafer 1-1.5 μm SiO ₂ isolation layer to release the beam structure; 9) One side of the upper cover is photo-etched, and the upward active area of the mass block is etched with hydrofluoric acid buffer solution BOE, and the height of the active area is also the height after considering the damping characteristics; 10) The silicon chip is sealed and connected with the upper cover plate (1) and the lower cover plate (2) by anodic bonding, so as to make a sandwich structure of glass-silicon chip-glass; 11) Device package: a. Use a mechanical dicing machine to scribe according to the dicing lane to make a sensitive accelerometer chip; b. Paste the above-mentioned chip into the ceramic square casing for packaging with AB glue; c. Use a gold wire ball welding machine to connect the fine gold wire and The pads on the sensitive chip are bonded one by one; d. Install the ceramic shell with a sealed shell cap and seal it with AB glue. 7. A manufacturing method of a six-axis integrated micro-acceleration sensor, characterized in that: the materials of the upper cover plate (1) and the lower cover plate (2) are American Corning 7740 glass or German Schott BF33 glass for anodic bonding.