MEMS packaging methods

Abstract

The present invention relates to a MEMS packaging method, comprising the following steps: S1, bonding a device layer wafer to a substrate; S2, etching the device layer wafer to obtain an acceleration sensor structure and a gyroscope structure; S3, pre-bonding an upper cover plate to the acceleration sensor structure and the gyroscope structure in a nitrogen atmosphere, so that the acceleration sensor structure cavity and the gyroscope structure cavity between the upper cover plate and the substrate are filled with nitrogen; S4, eliminating the nitrogen in the gyroscope structure cavity and bonding both the acceleration sensor structure and the gyroscope structure to the upper cover plate to obtain a gyroscope structure vacuum chamber. The present invention achieves the fabrication of an acceleration sensor chip and a gyroscope chip on a single substrate through MEMS packaging, shortening the fabrication process and reducing the cycle and cost of MEMS chip manufacturing. Furthermore, by combining and nesting different types of MEMS-level packaging methods, the two chips can be co-packaged, reducing the packaging volume and improving space utilization and integration capabilities.

Description

Technical Field

[0001] The present invention relates to the field of micro-nano inertial sensing technology, and in particular to a MEMS packaging method. Background Art

[0002] A high-precision inertial measurement unit (IMU) generally consists of three single-axis accelerometers and three single-axis gyroscopes and corresponding dedicated integrated circuits. The two can measure the axial acceleration and angular velocity signals respectively, calculate the motion posture of the moving object through data processing, and then complete navigation, guidance and timing.

[0003] In high-precision inertial sensors, MEMS accelerometers must operate in an underdamped N₂ atmosphere, while MEMS gyroscopes must operate in a vacuum. Therefore, two approaches are commonly used in existing technologies: one is to use a single MEMS chip in a separate package, and the other is to first vacuum-package the MEMS accelerometer and MEMS gyroscope together, then open a hole above the MEMS accelerometer and fill it with N₂ before performing a secondary package to ensure that the different MEMS chips can function properly. However, both packaging methods require multiple wafer-level packaging processes, which results in a long production cycle and high costs. Summary of the Invention

[0004] The object of the present invention is to provide a MEMS packaging method that can at least solve some of the defects in the prior art.

[0005] To achieve the above objectives, an embodiment of the present invention provides the following technical solution: a MEMS packaging method, comprising the following steps:

[0006] S1, bonding the device layer wafer on the substrate;

[0007] S2, etching the device layer wafer to obtain an acceleration sensor structure and a gyroscope structure;

[0008] S3, pre-bonding an upper cover plate onto the acceleration sensor structure and the gyroscope structure in a nitrogen atmosphere, so that the acceleration sensor structure cavity and the gyroscope structure cavity between the upper cover plate and the substrate are filled with nitrogen;

[0009] S4, eliminating nitrogen in the cavity of the gyro structure, and bonding the acceleration sensor structure and the gyro structure to the upper cover plate to obtain a gyro structure vacuum chamber.

[0010] Furthermore, in the step S4, the upper cover plate is bonded to the acceleration sensor structure in the following manner:

[0011] preparing glass paste at a pre-bonding position between the acceleration sensor structure and the upper cover plate;

[0012] The upper cover plate is pressed onto the acceleration sensor structure, and the glass paste is heated during the application of pressure, so that the glass paste melts to bond the upper cover plate onto the acceleration sensor structure.

[0013] Furthermore, in the step S3, the upper cover plate is pre-bonded to the gyro structure in the following manner:

[0014] Making a sacrificial block at a pre-bonding position between the gyro structure and the upper cover plate;

[0015] A metal eutectic point is formed on the surface of the gyro structure facing the upper cover plate, and the sacrificial block and the metal eutectic point are arranged opposite to each other;

[0016] The sacrificial block is docked with the metal eutectic point.

[0017] Furthermore, the specific method of step S4 is as follows:

[0018] releasing the sacrificial block, and extracting the nitrogen in the cavity of the gyro structure through the gap formed by the release of the sacrificial block;

[0019] The bonding position of the upper cover plate falls on the metal eutectic point;

[0020] The upper cover plate and the device layer wafer are bonded via the metal eutectic point to obtain the gyro structure vacuum chamber.

[0021] Furthermore, the specific method of releasing the sacrificial block is: pressing the upper cover plate onto the acceleration sensor structure and the gyroscope structure, and heating the sacrificial block during the process of applying pressure, and at the same time introducing oxygen into the sacrificial block so that the bonding position of the upper cover plate falls on the metal eutectic point.

[0022] Furthermore, the specific method of heating the sacrificial block during the process of applying pressure is:

[0023] Prepare an upper clamping plate and a lower clamping plate that are arranged opposite each other, wherein the lower clamping plate rests on the base and the upper clamping plate is pressed onto the upper cover plate;

[0024] The upper clamping plate and the lower clamping plate are closed, and the upper clamping plate and / or the lower clamping plate are heated.

[0025] Furthermore, a top cover substrate is taken and a plurality of bumps are made on the top surface of the substrate; sacrificial blocks are made on the bumps of the top cover corresponding to the gyro structure; the substrate is turned over so that each bump is pre-bonded to the metal eutectic point through the sacrificial blocks.

[0026] Furthermore, before obtaining the acceleration sensor structure and the gyroscope structure, the device layer wafer is first etched to obtain an overflow groove.

[0027] Further, before the S1 step:

[0028] Etching downwards on the substrate to form a plurality of grooves, wherein two adjacent grooves are separated by scribing lanes, and each of the two adjacent grooves has a support anchor point;

[0029] On the etched substrate, multiple insulating layers and multiple metal layers are alternately deposited in sequence;

[0030] A plurality of first through holes are formed on the insulating layer between two adjacent metal layers to allow the two adjacent metal layers to be electrically connected;

[0031] The uppermost insulating layer on the support anchor point and the area outside the groove is removed to expose the metal layer, and the area where the exposed metal layer is located is the bonding area.

[0032] Furthermore, both the step S3 and the step S4 are completed using a bonding machine.

[0033] Compared with the existing technology, the beneficial effects of the present invention are: the acceleration sensor chip and the gyroscope chip are prepared on a substrate through MEMS packaging, which shortens the preparation process, reduces the cycle and cost of MEMS chip manufacturing, and realizes the joint packaging of the two chips through the combination and nesting of different types of MEMS-level packaging methods, reduces the packaging volume, and improves space utilization and integration capabilities. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A schematic diagram of a substrate for a MEMS packaging method provided by an embodiment of the present invention;

[0035] Figure 2 A schematic diagram of a MEMS packaging method after etching a substrate provided by an embodiment of the present invention;

[0036] Figure 3 A schematic diagram of depositing a first insulating layer in a MEMS packaging method provided by an embodiment of the present invention;

[0037] Figure 4 A schematic diagram of manufacturing a first metal layer in a MEMS packaging method provided by an embodiment of the present invention;

[0038] Figure 5 A schematic diagram of depositing a second insulating layer and opening a through hole in a MEMS packaging method provided by an embodiment of the present invention;

[0039] Figure 6A schematic diagram of a MEMS packaging method for manufacturing a second metal layer provided by an embodiment of the present invention;

[0040] Figure 7 A schematic diagram of a MEMS packaging method provided by an embodiment of the present invention, which shows depositing a third insulating layer and removing the third insulating layer on the support anchor points and the area outside the groove;

[0041] Figure 8 A schematic diagram of bonding a device layer wafer in a MEMS packaging method provided by an embodiment of the present invention;

[0042] Figure 9 A schematic diagram of a MEMS packaging method provided in an embodiment of the present invention for thinning a device layer wafer and fabricating an overflow groove and a metal eutectic point;

[0043] Figure 10 A schematic diagram of a MEMS packaging method provided by an embodiment of the present invention, wherein a through hole is formed in a region of a device layer wafer facing the groove;

[0044] Figure 11 A schematic diagram of a MEMS packaging method for making bumps on a cover according to an embodiment of the present invention;

[0045] Figure 12 A schematic diagram of a MEMS packaging method for preparing glass paste and a sacrificial block according to an embodiment of the present invention;

[0046] Figure 13 A schematic diagram of a MEMS packaging method provided in an embodiment of the present invention for pre-bonding a cover plate and a device layer wafer in a nitrogen atmosphere;

[0047] Figure 14 A schematic diagram of a MEMS packaging method provided in an embodiment of the present invention, wherein the cavity of a gyroscope chip is made into a vacuum chamber and the upper cover plate and the device layer wafer are bonded;

[0048] In the figure, numerals indicate: 1-substrate; 10-support anchor point; 11-dicing lane; 12-groove; 2-first insulating layer; 3-first metal layer; 4-second insulating layer; 40-first through hole; 5-second metal layer; 6-third insulating layer; 7-device layer wafer; 70-overflow groove; 71-metal eutectic point; 72-second through hole; 8-upper cover; 80-bump; 81-glass paste; 82-sacrificial block; 90-nitrogen; 91-vacuum chamber. DETAILED DESCRIPTION

[0049] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0050] See also Figures 1 to 14 , an embodiment of the present invention provides a MEMS packaging method, comprising the following steps: S1, bonding a device layer wafer 7 on a substrate 1; S2, etching the device layer wafer 7 to obtain an acceleration sensor structure and a gyroscope structure; S3, pre-bonding an upper cover plate 8 on the acceleration sensor structure and the gyroscope structure under a nitrogen atmosphere, so that the acceleration sensor structure cavity and the gyroscope structure cavity between the upper cover plate 8 and the substrate 1 are filled with nitrogen; S4, eliminating the nitrogen in the gyroscope structure cavity, and bonding the acceleration sensor structure and the gyroscope structure to the upper cover plate 8 to obtain a gyroscope structure vacuum chamber. In this embodiment, the acceleration sensor chip and the gyroscope chip are prepared on a substrate through MEMS packaging, which shortens the preparation process, reduces the cycle and cost of MEMS chip manufacturing, and realizes the joint packaging of the two chips through the combination and nesting of different types of MEMS-level packaging methods, reduces the packaging volume, and improves space utilization and integration capabilities. Specifically, Figure 7 As shown, the dicing lanes 11 are divided (i.e. Figure 13 and Figure 14 The left side is the acceleration sensor structure, and the right side is the gyroscope structure, as shown in the figure. Figure 8 As shown, continue to bond the device layer wafer 7. After the device layer wafer 7 is bonded, as shown in FIG. Figure 13 As shown, the upper cover plate 8 is pre-bonded on the device layer wafer 7 in a nitrogen atmosphere of 90°C. Figure 14 As shown, after eliminating the nitrogen 90 in the cavity between the gyro structure and the upper cover 8, the cavity is made into a vacuum chamber 91, and after completing the bonding between the upper cover 8 and the device layer wafer 7, the acceleration sensor chip and the gyro chip can be packaged at the MEMS level. Figure 14 As shown, after preparation, the left side of the dicing road 11 is the acceleration sensor chip, and the right side is the gyroscope chip. First, the accelerometer structure production area and the gyroscope structure production area are divided on the base, and there is a dicing road 11 between the acceleration sensor structure production area and the gyroscope structure production area; then, the acceleration sensor structure and the gyroscope structure can be obtained by etching the device layer wafer. Preferably, Figures 1 to 14The overall manufacturing process steps of this method are carried out in sequence. The structure shown in the next figure is a change in the sequence of steps based on the structure shown in the previous figure. Preferably, both step S3 and step S4 are completed using a bonding machine.

[0051] See also Figure 12 、 Figure 13 and Figure 14 In the step S3, in the step S4, the upper cover plate 8 is bonded to the acceleration sensor structure in the following manner: glass paste 81 is prepared at the pre-bonding position between the acceleration sensor structure and the upper cover plate 8; the upper cover plate 8 is pressed onto the acceleration sensor structure, and the glass paste 81 is heated during the application of pressure, so that the glass paste 81 melts to bond the upper cover plate 8 to the acceleration sensor structure. In this embodiment, the acceleration sensor structure and the upper cover plate 8 are pre-bonded by bonding with the glass paste 81. The upper cover plate 8 is pressed onto the device layer wafer 7, and is heated during the pressing process, so that the glass paste 81 melts and bonds to the upper cover plate 8. In combination with the above embodiment, after the nitrogen is extracted through the gap released by the sacrificial block, it is continuously extracted into the vacuum chamber and maintained there, and then the glass paste is heated and pressurized in its molten state so that the bonding position of the upper cover plate falls on the metal eutectic point. When the bonding position of the upper cover plate and the metal eutectic point are bonded, the acceleration sensor structure and the upper cover plate are also bonded.

[0052] See also Figure 12 、 Figure 13 and Figure 14In step S3, the upper cover plate is pre-bonded to the gyro structure in the following manner: a sacrificial block 82 is formed at the pre-bonding position between the gyro structure and the upper cover plate 8; a metal eutectic point 71 is formed on the surface of the gyro structure facing the upper cover plate 8; the sacrificial block 82 and the metal eutectic point 71 are arranged opposite each other, and the sacrificial block 82 is located above the metal eutectic point 71; and the sacrificial block 82 is docked with the metal eutectic point 71; preferably, the specific manner of step S4 is: releasing the sacrificial block 82, and extracting nitrogen in the cavity of the gyro structure through the gap formed by the release of the sacrificial block 82; the bonding position of the upper cover plate 8 falls on the metal eutectic point 71; and the upper cover plate 8 is bonded to the device layer wafer through the metal eutectic point 71 to obtain the gyro structure vacuum chamber 91. This bonding is eutectic bonding. In this embodiment, the method of making the vacuum chamber 91 is to introduce a sacrificial block 82. Before releasing the sacrificial block 82, the sacrificial block 82 has a certain thickness and can support the upper cover plate 8 above the device layer wafer 7. In addition, the sacrificial block 82 can also be used to locate the pre-bonding position. After the sacrificial block 82 and the metal eutectic point 71 are made, the sacrificial block 82 is released. After the sacrificial block 82 disappears, the upper cover plate 8 will naturally fall on the metal eutectic point 71. Then, after the pre-bonding position of the upper cover plate 8 is bonded to the metal eutectic point 71, the cavity between the gyro structure and the upper cover plate 8 can be closed, thereby obtaining the vacuum chamber 91. It can be said that the action of obtaining the vacuum chamber 91 is synchronized with the bonding action. After bonding, the cavity between the gyro structure and the upper cover plate 8 is closed. Before this, the cavity is in a vacuum state, so the vacuum chamber 91 can be obtained after closing.

[0053] To further optimize the above scheme, the specific method of releasing the sacrificial block 82 is: pressing the upper cover plate 8 on the acceleration sensor structure and the gyroscope structure, and heating the sacrificial block 82 during the process of applying pressure, while introducing oxygen into the sacrificial block 82. The sacrificial block 82 is consumed after reacting with the oxygen, and the bonding position of the upper cover plate 8 falls on the metal eutectic point 71. In this process, a bonding machine can be used to complete the bonding of the upper cover plate and the device layer wafer, as well as the production of the vacuum chamber. Specifically, the bonding machine can complete the introduction of oxygen and nitrogen, and evacuation. Preferably, the specific method of heating the sacrificial block 82 during the process of applying pressure is: preparing an upper clamp and a lower clamp that are arranged opposite each other, the lower clamp rests on the substrate 1, and the upper clamp is pressed onto the upper cover plate 8; closing the upper clamp and the lower clamp, and heating the upper clamp and / or the lower clamp. The bonding machine can utilize upper and lower clamps to clamp and apply force. For example, an upper clamp is used to press down on the upper cover plate 8, and the lower clamp is used to support the substrate 1. This way, the entire structure is clamped between the upper and lower clamps, and the upper and lower clamps can be used to provide clamping force, thereby applying pressure. Simultaneously, the upper and lower clamps can generate heat, thereby providing a high-temperature environment to eliminate the sacrificial block 82. The upper and lower clamps can generate heat simultaneously to provide a more uniform heating environment, or heating one of them is also feasible. The sacrificial block 82 is eliminated by introducing oxygen to induce a reaction and consume it. Any existing sacrificial block 82 material that reacts with oxygen after heating can be used in this embodiment, such as polyimide, but this embodiment does not limit this. After the sacrificial block 82 is consumed, since it has already aligned well with the bonding position, the bonding position of the upper cover plate 8 can naturally fall on the metal eutectic point 71. Since it is now in a heated environment, sufficient heat can cause the upper cover plate 8 to form a metal eutectic with the metal eutectic point 71, thereby achieving bonding.

[0054] See also Figure 11 and Figure 12In the above steps, a top cover plate 8 substrate is prepared, and several bumps 80 are formed on its upper surface. Glass paste 81 is applied to each bump 80 of the top cover plate 8 corresponding to the acceleration sensor structure, and sacrificial blocks 82 are applied to each bump 80 of the top cover plate 8 corresponding to the gyroscope structure. The substrate is flipped so that each bump 80 faces the acceleration sensor structure and the gyroscope structure, and pre-bonded thereto. In this embodiment, a top cover plate 8 substrate is prepared, and several bumps 80 are formed thereon. The spaces between adjacent bumps 80 form the cavity of the top cover plate 8 described in the above embodiment, which can also be considered as grooves 12. These bumps 80 are also the bonding locations of the top cover plate 8, through which the acceleration sensor structure and gyroscope structure below are bonded. After the bumps 80, the glass paste 81, and the sacrificial blocks 82 are formed on the top cover plate 8, the substrate is flipped so that the bumps 80 face the device layer wafer 7. This step also constitutes pre-bonding.

[0055] See also Figure 9 Before obtaining the acceleration sensor structure and the gyroscope structure, the device layer wafer 7 is first etched to obtain an overflow groove 70. In this embodiment, the overflow groove 70 can be located at the bonding position between the acceleration sensor structure and the upper cover plate 8, so that the molten excess glass paste 81 flows away from the overflow groove 70. Of course, if the gyroscope structure also has similar overflow requirements, the overflow groove can also be etched in the gyroscope structure. The overflow groove 70 can be designed in the following manner: Figure 13 As Figure 14 When the glass slurry 81 flows away from the overflow tank 70, Figure 13 In the process, the glass paste 81 has not been squeezed yet and is in a block structure. Figures 13 to 14 During the process, the upper cover plate 8 is pressed down, and the glass paste 81 is squeezed and deformed, usually as shown in FIG. Figure 14 As shown, the glass paste 81 that is squeezed out overflows to the periphery. By setting an overflow groove 70 at the bonding position, the glass paste 81 that is squeezed out can be guided away.

[0056] See also Figure 13 and Figure 14 In the step S4, the specific method of eliminating the nitrogen 90 in the cavity between the gyro structure and the upper cover plate 8 is to extract the nitrogen 90 in the cavity from the gap between the upper cover plate 8 and the gyro structure. The nitrogen 90 in the cavity can be extracted by extraction, that is, Figure 13 As shown, the nitrogen 90 in the cavity on the right is extracted, specifically, the nitrogen 90 is extracted from the gap between the upper cover plate 8 and the gyro structure.

[0057] See also Figures 1 to 7Before the S1 step: a plurality of grooves 12 are formed by etching downward on the substrate 1, and two adjacent grooves 12 are separated by a scribe line 11, and each of the two adjacent grooves 12 has a support anchor point 10; multiple insulating layers and multiple metal layers are alternately deposited on the etched substrate 1; a plurality of first through holes 40 are opened on the insulating layer between two adjacent metal layers to make the two adjacent metal layers conductive; the support anchor point 10 and the uppermost insulating layer on the area outside the groove 12 are removed to expose the metal layer, and the area where the exposed metal layer is located is the bonding area. Preferably, the alternating deposition method is as follows: first, a first insulating layer 2 is deposited on the etched substrate 1; a first metal layer 3 is formed on the first insulating layer 2; a second insulating layer 4 is deposited on the first metal layer 3, and a plurality of first through holes 40 are opened on the second insulating layer 4 in the groove 12 to expose the first metal layer 3; a second metal layer 5 is formed on the second insulating layer, and the second metal layer 5 in the groove 12 is electrically connected to the first metal layer 3; a third insulating layer 6 is deposited on the second metal layer 5, and the third insulating layer 6 on the support anchor 10 and the area outside the groove 12 is removed to expose the second metal layer, and the area where the second metal layer is located is the bonding area. In this embodiment, the number of insulating layers and the number of metal layers can be selected as needed, and are not limited to the number of layers shown in this embodiment, but it should be noted that enough first through holes 40 are designed to electrically connect two adjacent metal layers. Through the above method, the acceleration sensor structure and the gyroscope structure can be simultaneously manufactured on the same substrate 1. This device layer wafer-level joint packaging greatly shortens the preparation process, reduces the cycle and cost of MEMS chip manufacturing, and through the combined nesting of different types of MEMS-level packaging methods, the joint packaging of the two chips is achieved, reducing the packaging volume and improving space utilization and integration capabilities.

[0058] To further optimize the above solution, please refer to Figure 10 , the etching of the device layer wafer 7 is specifically as follows: a second through hole 72 is opened in the area of ​​the device layer wafer 7 facing the groove 12 to connect the cavity between the upper cover plate 8 and the acceleration sensor structure and the cavity between the upper cover plate 8 and the gyroscope structure. In this embodiment, by designing the second through hole 72, the cavity of the upper cover plate 8 can be connected with the cavity of the acceleration sensor structure, and the cavity of the upper cover plate 8 can be connected with the cavity of the gyroscope structure, so that the groove 12 of the substrate 1 and the cavity of the upper cover plate 8 are filled with nitrogen 90 or a vacuum chamber 91 is formed. Figure 10 The acceleration sensor structure and the gyroscope structure are located on both sides of the dicing road 11. Figure 13 and Figure 14, the left and right sides of the dotted line are the acceleration sensor structure and the gyroscope structure with an additional cover plate respectively.

[0059] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A MEMS packaging method, characterized in that: The steps include: S1, bonding the device layer wafer on the substrate; S2, etching the device layer wafer to obtain an acceleration sensor structure and a gyroscope structure; S3, pre-bonding an upper cover plate onto the acceleration sensor structure and the gyroscope structure in a nitrogen atmosphere, so that the acceleration sensor structure cavity and the gyroscope structure cavity between the upper cover plate and the substrate are filled with nitrogen; S4, eliminating nitrogen in the cavity of the gyro structure, and bonding the acceleration sensor structure and the gyro structure to the upper cover plate to obtain a gyro structure vacuum chamber; In the step S3, the upper cover plate is pre-bonded to the gyro structure in the following manner: Making a sacrificial block at a pre-bonding position between the gyro structure and the upper cover plate; A metal eutectic point is formed on the surface of the gyro structure facing the upper cover plate, and the sacrificial block and the metal eutectic point are arranged opposite to each other; The sacrificial block is docked with the metal eutectic point.

2. The MEMS packaging method according to claim 1, wherein: In the step S4, the upper cover plate is bonded to the acceleration sensor structure in the following manner: preparing glass paste at a pre-bonding position between the acceleration sensor structure and the upper cover plate; The upper cover plate is pressed onto the acceleration sensor structure, and the glass paste is heated during the application of pressure, so that the glass paste melts to bond the upper cover plate onto the acceleration sensor structure.

3. The MEMS packaging method according to claim 1, wherein: The specific method of the S4 step is: releasing the sacrificial block, and extracting the nitrogen in the cavity of the gyro structure through the gap formed by the release of the sacrificial block; The bonding position of the upper cover plate falls on the metal eutectic point; The upper cover plate and the device layer wafer are bonded via the metal eutectic point to obtain the gyro structure vacuum chamber.

4. The MEMS packaging method according to claim 3, wherein: The specific method of releasing the sacrificial block is: pressing the upper cover plate onto the acceleration sensor structure and the gyroscope structure, heating the sacrificial block during the application of pressure, and simultaneously introducing oxygen into the sacrificial block so that the bonding position of the upper cover plate falls on the metal eutectic point.

5. The MEMS packaging method according to claim 4, wherein: The specific method of heating the sacrificial block during the application of pressure is: Prepare an upper clamping plate and a lower clamping plate that are arranged opposite each other, wherein the lower clamping plate rests on the base and the upper clamping plate is pressed onto the upper cover plate; The upper clamping plate and the lower clamping plate are closed, and the upper clamping plate and / or the lower clamping plate are heated.

6. The MEMS packaging method according to claim 1, wherein: Take the upper cover plate substrate, make a plurality of bumps on the upper surface of the substrate; make the sacrificial block on each bump of the upper cover plate corresponding to the gyro structure; turn the substrate over so that each bump is pre-bonded on the metal eutectic point through the sacrificial block.

7. The MEMS packaging method according to claim 1, wherein: Before obtaining the acceleration sensor structure and the gyroscope structure, the device layer wafer is first etched to obtain an overflow groove.

8. The MEMS packaging method according to claim 1, wherein: Before the S1 step, the method further includes: Etching downwards on the substrate to form a plurality of grooves, wherein two adjacent grooves are separated by scribing lanes, and each of the two adjacent grooves has a support anchor point; On the etched substrate, multiple insulating layers and multiple metal layers are alternately deposited in sequence; A plurality of first through holes are formed on the insulating layer between two adjacent metal layers to allow the two adjacent metal layers to be electrically connected; The uppermost insulating layer on the support anchor point and the area outside the groove is removed to expose the metal layer, and the area where the exposed metal layer is located is the bonding area.

9. The MEMS packaging method according to claim 1, wherein: The step S3 and the step S4 are both completed using a bonding machine.

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