An embedded six-axis inertial sensing system-level packaging structure and assembly method thereof

Abstract

The present invention relates to an embedded six-axis inertial sensing system-level packaging structure and an assembly method thereof. The packaging structure includes a special-shaped multi-cavity multi-layer wiring ceramic block; the special-shaped multi-cavity multi-layer wiring ceramic block is used to realize the integrated installation of a MEMS sensor unit and a data processing circuit. The special-shaped multi-cavity multi-layer wiring ceramic block includes a ceramic block; a plurality of MEMS sensor units are embedded and installed on the ceramic block; a cavity unit for fixing the MEMS sensor unit is provided on the ceramic block; and a data processing circuit installation area is provided on the top of the ceramic block. The present invention can ensure good measurement accuracy and reliability of the sensing system while reducing the packaging volume and weight, and can also form a standard inertial sensing functional unit that can be installed in navigation and flight control SiP systems.

Description

Technical Field

[0001] The present invention relates to the technical field of six-axis inertial sensing system-level packaging, and in particular to an embedded six-axis inertial sensing system-level packaging structure and an assembly method thereof. Background Art

[0002] As the requirements of navigation and control systems for the integration, volume, accuracy, and reliability of inertial sensing systems continue to increase, inertial sensing systems in various packaging structures emerge in an endless stream.

[0003] At present, there are two common packaging structures for high-precision inertial sensing systems. One is to encapsulate the MEMS sensor chip and the sensor signal detection circuit in a ceramic or metal shell and then install it on a PCB board, and then install it on a metal structure frame according to the orthogonal layout principle, and realize electrical connection with the data processing circuit PCB board through flexible cables or flying wires. The other is to encapsulate the MEMS sensor chip and the sensor signal detection circuit in a ceramic or metal shell and then install it on a cubic ceramic block with surface wiring. The former method involves many installation processes, introduces large installation errors, is large in size, and has high costs. In the latter method, the ceramic body can only have simple wiring on the surface, and the data processing circuit cannot be installed. In addition, the internal space of the solid ceramic cannot be utilized and is heavy.

[0004] Therefore, in order to solve the deficiencies in the prior art, it is urgent to realize an embedded six-axis inertial sensing system-level packaging structure. Summary of the invention

[0005] The object of the present invention is to provide an embedded six-axis inertial sensing system-level packaging structure and an assembly method thereof, which can solve the deficiencies in the prior art, reduce the packaging volume and weight, and ensure good accuracy, orthogonality and reliability, and can form a standard inertial sensing functional unit that can be installed in a navigation or flight control SiP system.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] An embedded six-axis inertial sensing system-level packaging structure comprises a special-shaped multi-cavity multi-layer wiring ceramic block; the special-shaped multi-cavity multi-layer wiring ceramic block is used to realize the integrated installation of a MEMS sensor unit and a data processing circuit.

[0008] The special-shaped multi-cavity multi-layer wiring ceramic block includes a ceramic block; a plurality of MEMS sensor units are embedded and installed on the ceramic block; a cavity unit for fixing the MEMS sensor unit is opened on the ceramic block; the cavity unit includes a first cavity and a second cavity respectively arranged at the two ends of the top of the ceramic block, a third cavity and a fourth cavity respectively arranged at the two ends of the front wall of the ceramic block, and a fifth cavity arranged in the middle of the bottom of the ceramic block; a data processing circuit installation area is arranged on the top of the ceramic block.

[0009] Furthermore, a first groove is provided in the middle of the front wall of the ceramic block, and the third cavity and the fourth cavity are located on both sides of the first groove; a second groove is provided in the middle of the bottom of the ceramic block; and the fifth cavity is provided in the middle of the second groove.

[0010] Furthermore, the MEMS sensor unit includes a ceramic substrate with multi-layer wiring; a sensor signal detection circuit and a first pad are installed on the top of the ceramic substrate; the first pad is used to be connected to the special-shaped multi-cavity multi-layer wiring ceramic block by gold wire bonding; a MEMS sensor chip and a second pad are installed on the bottom of the ceramic substrate; the second pad is used to be welded to the special-shaped multi-cavity multi-layer wiring ceramic block.

[0011] Furthermore, a third pad and a fourth pad are provided on the top of the ceramic block; the third pad is used to interconnect with the MEMS sensor unit through welding; the fourth pad is used to interconnect with an external navigation or flight control SiP system through gold wire bonding.

[0012] Furthermore, a third groove and a fourth groove are respectively arranged on both sides of the second groove; a fifth pad is arranged in each of the third groove and the fourth groove; the fifth pad is used to realize gold wire bonding interconnection with the MEMS sensor unit; sixth pads are respectively arranged at both ends of the bottom of the ceramic block; the sixth pad is used to realize welding connection with an external navigation or flight control SiP system.

[0013] Furthermore, the material of the ceramic block is Al2O3, and there are multiple layers of high-density wiring inside the ceramic block.

[0014] Furthermore, a data processing circuit is installed in the middle of the top of the ceramic block; the data processing circuit adopts a silicon-based bare chip.

[0015] Furthermore, the orthogonality between adjacent mounting surfaces of the special-shaped multi-cavity multi-layer wiring ceramic block is 90°±0.1°, the flatness is ≤0.05mm, and the warpage is ≤50 / 25μm / mm.

[0016] Furthermore, the ceramic substrate is made of Al2O3; the sensor signal detection circuit is fixed on the ceramic substrate by a bare chip flip-chip welding process; the MEMS sensor chip is fixed on the ceramic substrate by a bonding process, and is electrically connected to the ceramic substrate by a gold wire bonding process.

[0017] The present invention also includes an assembly method of the above-mentioned embedded six-axis inertial sensing system-level packaging structure, the method comprising the following steps:

[0018] S1, the X-axis MEMS sensor unit and the Y-axis MEMS sensor unit are respectively installed in the first cavity, the second cavity, the third cavity and the fourth cavity of the special-shaped multi-cavity multi-layer wiring ceramic block by bonding, wherein the side of the MEMS sensor unit equipped with the MEMS sensor chip is embedded in the cavity and placed toward the inner side of the cavity, and the second pad of the MEMS sensor unit and the third pad on the special-shaped multi-cavity multi-layer wiring ceramic block are electrically connected by welding.

[0019] S2. The Z-axis MEMS sensor unit is installed in the fifth cavity in the middle of the bottom of the special-shaped multi-cavity multi-layer wiring ceramic block by bonding, wherein the side of the MEMS sensor unit equipped with the MEMS sensor chip is embedded in the fifth cavity and placed toward the inside of the cavity, and the first pad of the MEMS sensor unit and the fifth pad on the back of the special-shaped multi-cavity multi-layer wiring ceramic block are electrically connected through gold wire bonding.

[0020] Compared with the prior art, the advantages of the present invention are:

[0021] (1) The present invention relates to an embedded six-axis inertial sensing system-level packaging structure that can be used in micro-aircraft navigation and flight control systems. The packaging structure can ensure good sensing system measurement accuracy and reliability while reducing the packaging volume and weight, and can also form a standard inertial sensing functional unit that can be installed in navigation and flight control SiP systems. The embedded six-axis inertial sensing system-level packaging structure described in the present invention uses a bare chip micro-assembly process based on a ceramic substrate. Compared with the traditional PCB process, the stress and thermal expansion coefficient between the ceramic substrate and the silicon-based bare chip and the MEMS sensor chip are well matched, and have good heat dissipation performance, which helps to improve the sensing accuracy and reliability of the system. Since the MEMS sensor chip is sensitive to heat and stress, the sensor signal detection circuit cannot be stacked and assembled with it. The traditional solution can only install both of them flatly on one side in a ceramic housing. The present invention assembles the MEMS sensor chip and the sensor signal detection circuit on the two sides of the ceramic substrate respectively, thereby increasing the assembly density of the MEMS sensor unit and reducing the transmission line distance of the sensor signal, thereby improving the detection accuracy.

[0022] (2) The data processing circuit in the present invention uses a special-shaped multi-cavity multi-layer wiring ceramic block as a substrate, and the substrate uses Al2O3 as its base material. Through hard film isostatic pressing, controlling the heating and cooling curves during debinding and sintering, and using mold leveling, double-sided slicing with a grinding wheel and fine grinding after sintering, multiple open cavities are processed on the special-shaped multi-cavity multi-layer wiring ceramic block, and the flatness, warpage and orthogonality of the ceramic block meet the requirements of the MEMS sensor unit and its assembly, and each MEMS sensor unit can be embedded and installed. Each cavity set in the special-shaped multi-cavity multi-layer wiring ceramic block can not only reduce the weight of the ceramic block, but also realize the embedded installation of the MEMS sensor unit, thereby improving the structural integration of the inertial sensing system and reducing the structural volume.

[0023] (3) Since the double-sided assembled MEMS sensor unit circuit cannot be directly installed and fixed, the packaging structure described in the present invention can embed the side with the MEMS sensor chip installed in the cavity processed on the ceramic block, so that the side with the MEMS sensor chip installed faces the inside of the cavity. In this way, the MEMS sensor unit can be fixed on the ceramic block by bonding by relying on the spare substrate surface around the MEMS sensor chip. Since the MEMS sensor chip is sensitive to heat, the MEMS sensor unit is embedded in each cavity on the ceramic block, which can reduce the installation contact surface between the MEMS sensor unit and the ceramic block and reduce the heat transferred from the data processing circuit on the top of the ceramic block to the MEMS sensor unit. In addition, the side with the MEMS sensor chip installed is embedded in the cavity and placed toward the inside of the cavity, which can also slow down the impact of external system thermal radiation / thermal convection on the MEMS sensor chip, slow down its temperature change rate, and help improve the system sensing accuracy. Although the sensor signal detection circuit can be flip-chip welded, the MEMS sensor chip can only be electrically connected by gold wire bonding. Each MEMS sensor unit in the present invention has one side equipped with the MEMS sensor chip embedded in the cavity and placed toward the inside of the cavity. This design can prevent the packaging structure from touching the bonding wire during assembly and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the structure of the embedded six-axis inertial sensing system-level packaging structure in the present invention. Figure 1 ;

[0025] Figure 2 This is a schematic diagram of the structure of the embedded six-axis inertial sensing system-level packaging structure in the present invention. Figure 2 ;

[0026] Figure 3 is a schematic diagram of a MEMS sensor unit in the present invention;

[0027] Figure 4The structure of the special-shaped multi-cavity multi-layer wiring ceramic block 200 of the present invention is shown in FIG. Figure 1 ;

[0028] Figure 5 The structure of the special-shaped multi-cavity multi-layer wiring ceramic block 200 of the present invention is shown in FIG. Figure 2 .

[0029] in:

[0030] 100. MEMS sensor unit, 101. sensor signal detection circuit, 102. MEMS sensor chip, 103. first pad, 104. second pad, 200. special-shaped multi-cavity multi-layer wiring ceramic block, 201. first cavity, 202. fifth cavity, 203. third pad, 204. data processing circuit, 205. fifth pad, 206. fourth pad, 207. sixth pad, 208. second cavity, 209. first groove, 210. third cavity, 211. fourth cavity, 212. second groove, 213. third groove, 214. fourth groove. DETAILED DESCRIPTION

[0031] The present invention will be further described below in conjunction with the accompanying drawings:

[0032] like Figure 1 and Figure 2 An embedded six-axis inertial sensing system-level packaging structure is shown, which includes six MEMS sensor units 100 based on a ceramic substrate and a special-shaped multi-cavity multi-layer wiring ceramic block 200 for realizing the integrated installation of the MEMS sensor unit 100 and the data processing circuit 204. The surfaces of the MEMS sensor unit 100 and the special-shaped multi-cavity multi-layer wiring ceramic block 200 are assembled using a micro-assembly process based on a bare chip. Compared with the traditional PCB process, the ceramic substrate used in the MEMS sensor unit 100 and the ceramic block used in the special-shaped multi-cavity multi-layer wiring ceramic block 200 have a better match between the stress and thermal expansion coefficient between the silicon-based bare chip and the MEMS sensor chip 102, and have better heat dissipation performance, which helps to improve the sensing accuracy and reliability of the system.

[0033] like Figure 3As shown, the MEMS sensor unit 100 is realized by a double-sided micro-assembly process based on a multi-layer ceramic substrate and a bare chip. Specifically, the MEMS sensor unit 100 includes a ceramic substrate with multi-layer wiring; a sensing signal detection circuit 101 and a first pad 103 are installed on the top of the ceramic substrate; a MEMS sensor chip 102 and a second pad 104 are installed on the bottom of the ceramic substrate; the first pad 103 is used to be connected to the special-shaped multi-cavity multi-layer wiring ceramic block 200 by gold wire bonding; the second pad 104 is used to be connected to the special-shaped multi-cavity multi-layer wiring ceramic block 200 by welding. The material of the ceramic substrate is Al2O3. The sensing signal detection circuit 101 is fixed on the ceramic substrate by a bare chip flip-chip welding process. The MEMS sensor chip 102 is fixed on the ceramic substrate by a bonding process, and is electrically connected to the ceramic substrate by a gold wire bonding process. The number of the MEMS sensor units 100 is 6, including 3 accelerometers and 3 gyroscopes. The sensor signal detection circuit 101 adopts a bare chip.

[0034] The present invention assembles the MEMS sensor chip 102 and the sensor signal detection circuit 101 on the upper and lower surfaces of the ceramic substrate respectively. This design not only improves the assembly density of the MEMS sensor unit, but also reduces the transmission line distance of the weak sensor signal, thereby improving the detection accuracy. The present invention uses a double-sided micro-assembly process based on a ceramic substrate to realize the assembly of the MEMS sensor chip 102, the sensor signal detection circuit 101 and the ceramic substrate, which not only improves the assembly density of the MEMS sensor unit, but also has good heat dissipation performance while realizing the miniaturization of the unit, and also realizes a high degree of matching of stress and thermal expansion coefficient between the bare chip used by the MEMS sensor chip 102 and the sensor signal detection circuit 101 and the ceramic substrate, which helps to improve the sensing accuracy and reliability of the system, and greatly reduces the transmission line distance of the weak sensor signal, further improving the detection accuracy.

[0035] like Figure 4 and Figure 5 As shown, the special-shaped multi-cavity multi-layer wiring ceramic block 200 includes a ceramic block.

[0036] The special-shaped multi-cavity multi-layer wiring ceramic block 200 has a data processing circuit 204 assembled on its surface. Multiple open cavities are processed through hard film isostatic pressing, control of debinding and heating and cooling curves during sintering, mold leveling after sintering, double-sided slicing with a grinding wheel, and fine grinding. The flatness, warpage, and orthogonality of the ceramic block meet the requirements of the MEMS sensor unit and its assembly. Six MEMS sensor units can be embedded and installed, which greatly improves the structural integration of the inertial sensing system and reduces the structural volume.

[0037] like Figure 4 As shown, a data processing circuit 204 is installed in the middle of the top of the ceramic block; the data processing circuit 204 adopts a silicon-based bare chip; the first cavity 201 and the second cavity 208 are respectively opened at the two ends of the top of the ceramic block; the first cavity 201 is used to assemble the X-axis accelerometer; the second cavity 208 is used to assemble the X-axis gyroscope. A first groove 209 is opened in the middle of the front wall of the ceramic block. By opening the first groove 209, when the MEMS sensor unit 100 is embedded and installed in the fifth cavity 202, it is convenient to use tweezers and other installation tools to clamp and install the MEMS sensor unit 100. A third cavity 210 and a fourth cavity 211 are respectively opened at the two ends of the front wall of the ceramic block. The third cavity 210 is used to assemble the Y-axis accelerometer; the fourth cavity 211 is used to assemble the Y-axis gyroscope; the top of the ceramic block is provided with a third pad 203 and a fourth pad 206. The third pad 203 is used to interconnect with the MEMS sensor unit 100 by welding; the fourth pad 206 is used to interconnect with an external navigation or flight control SiP system by gold wire bonding.

[0038] like Figure 5 As shown, a second groove 212 is provided at the middle position of the bottom of the ceramic block; a fifth cavity 202 is provided in the middle of the second groove; the fifth cavity 202 is used to assemble the Z-axis accelerometer and the Z-axis gyroscope; a third groove 213 and a fourth groove 214 are respectively provided on both sides of the second groove 212; a fifth pad 205 is provided in both the third groove 213 and the fourth groove 214; the fifth pad 205 is used to realize gold wire bonding interconnection with the MEMS sensor unit 100; a sixth pad 207 is provided at the bottom of the ceramic block; the sixth pad 207 is used to realize welding connection with an external navigation or flight control SiP system. By providing the second groove 212, after the MEMS sensor unit 100 is embedded and installed in the fifth cavity 202, the MEMS sensor unit 100 is located within the bottom surface of the ceramic block, so that when the six-axis inertial sensing system-level packaging structure is welded and connected to the external navigation or flight control SiP system through the sixth pad 207, the MEMS sensor unit 100 embedded and installed in the fifth cavity 202 will not be touched. Figure 2 As shown, the upper surface of the MEMS sensor unit 100 installed in the fifth cavity 202 is lower than the plane where the pad 207 is located. In this way, when installing external navigation or flight control SiP, if welding through the pad 207 is required, the MEMS sensor unit 100 embedded in the fifth cavity 202 will not be touched.

[0039] The cavities set at the top and bottom of the ceramic block can not only reduce the weight of the ceramic block, but also greatly improve the structural integration of the inertial sensing system and reduce the volume of the structure by embedding and installing the MEMS sensor unit 100 into each cavity. The MEMS sensor unit is bonded and fixed on the special-shaped multi-cavity multi-layer wiring ceramic block 200 by the free substrate surface around the MEMS sensor chip to achieve embedded installation. Due to the small bonding surface, under the premise of meeting the bonding strength, the heat transfer speed of the data processing circuit on the special-shaped multi-cavity multi-layer wiring ceramic block 200 to the MEMS sensor unit can be slowed down, avoiding the impact on the detection accuracy of the temperature-sensitive MEMS sensor chip. The sensor signal detection circuit on the six MEMS sensor units adopts flip-chip welding, but the MEMS sensor chip can only be connected by gold wire bonding. The six MEMS sensor units are all embedded and installed in the cavity with one side of the MEMS sensor chip installed, which can not only avoid the packaging structure from touching the bonding gold wire during assembly and use, but also can slow down the impact of external system heat radiation / heat convection on the detection accuracy of the MEMS sensor chip.

[0040] Preferably, according to the present invention, the top of the special-shaped multi-cavity multi-layer wiring ceramic block 200 is provided with a fourth pad 206 for realizing gold wire bonding interconnection with an external navigation or flight control SiP system, and the bottom of the special-shaped multi-cavity multi-layer wiring ceramic block 200 is provided with a sixth pad 207 for realizing welding connection with an external navigation or flight control SiP system. The design of the pads on the special-shaped multi-cavity multi-layer wiring ceramic block enables the embedded six-axis inertial sensing system-level packaging structure to be directly installed in the navigation or flight control SiP system as a standard functional unit.

[0041] Preferably, according to the present invention, the material of the ceramic block is Al2O3, and there are multiple layers of high-density wiring inside. The Al2O3 raw ceramic sheets are processed into ceramic blocks by lamination, debinding, sintering, leveling, slicing and grinding. Among them, the lamination process adopts isostatic pressing combined with hard film lamination plate limit protection technology to ensure that the cavity is free of deformation and the surface is flat; the debinding and sintering process controls the heating, insulation and cooling rates under a nitrogen environment to ensure that the cavity is flat and free of any stress deformation; the sintered ceramic block adopts hard mold leveling technology, and the cavity is flattened by an inner mold to ensure the flatness of the cavity; the double-sided slicing and fine grinding process of the grinding wheel is used to eliminate the uneven side walls of the ceramic block and correct the orthogonality between each surface. The orthogonality between adjacent mounting surfaces of the processed ceramic block reaches 90°±0.1°, the flatness is ≤0.05mm, and the warpage is ≤50 / 25μm / mm.

[0042] Preferably, the special-shaped multi-cavity multi-layer wiring ceramic block 200 is not only provided with a data processing circuit 204, but also realizes the embedded installation of the MEMS sensor unit 100. The surface of the ceramic block is processed with a plurality of cavities for the embedded installation of the MEMS sensor unit. The top of the ceramic block is provided with a first cavity 201 for assembling an X-axis accelerometer, a second cavity 208 for assembling an X-axis gyroscope, a third cavity 210 for assembling a Y-axis accelerometer, and a fourth cavity 211 for assembling a Y-axis gyroscope, and the bottom of the ceramic block is provided with a fifth cavity 202 for assembling a Z-axis accelerometer and a Z-axis gyroscope.

[0043] Preferably according to the present invention, a smooth and orthogonal irregular multi-cavity multi-layer wiring ceramic block 200 is used to respectively mount the three accelerometers and three gyroscopes in the MEMS sensor unit 100 on mounting surfaces orthogonal to each other, and electrical connection between the MEMS sensor unit 100 and the irregular multi-cavity multi-layer wiring ceramic block 200 is achieved through welding and gold wire bonding.

[0044] Preferably, according to the present invention, the MEMS sensor unit 100 uses a ceramic substrate with multi-layer wiring as a circuit carrier, and the data processing circuit 204 uses a ceramic block with multi-layer wiring as a circuit carrier. The MEMS sensor unit 100 adopts a hybrid integration process, and the MEMS sensor chip 102 and the sensor signal detection circuit 101 are respectively assembled on both sides of the ceramic substrate. The data processing circuit 204 is installed on the special-shaped multi-cavity multi-layer wiring ceramic block 200. The ceramic block in the special-shaped multi-cavity multi-layer wiring ceramic block 200 uses Al2O3 as a substrate, and is distributed with multiple open cavities. Multi-layer wiring is arranged inside the ceramic block, which can meet the wiring requirements of complex circuits. The 6 MEMS sensor units 100 are installed in the corresponding cavity positions of the special-shaped multi-cavity multi-layer wiring ceramic block 200 by a bonding process, so that they are embedded in the cavity.

[0045] The assembly method of the embedded six-axis inertial sensing system-level packaging structure of the present invention comprises the following steps:

[0046] S1, the X-axis MEMS sensor unit and the Y-axis MEMS sensor unit are respectively installed in the cavity positions on the four sides of the top of the special-shaped multi-cavity multi-layer wiring ceramic block 200 by bonding, namely the first cavity 201, the second cavity 208, the third cavity 210, and the fourth cavity 211, wherein the side on which the MEMS sensor chip 102 is installed is embedded in the cavity and placed facing inward, and the second pad 104 of the MEMS sensor unit and the third pad 203 on the special-shaped multi-cavity multi-layer wiring ceramic block 200 are electrically connected 301 by welding.

[0047] S2. The Z-axis MEMS sensor unit is installed in the fifth cavity 202 in the middle of the bottom of the special-shaped multi-cavity multi-layer wiring ceramic block 200 by bonding, wherein the side on which the MEMS sensor chip 102 is installed is embedded in the fifth cavity and placed facing inward, and the first pad 103 of the MEMS sensor unit and the fifth pad 205 on the back of the special-shaped multi-cavity multi-layer wiring ceramic block 200 are electrically connected 302 by gold wire bonding.

[0048] The six-axis inertial sensing system-level packaging structure described in the present invention can be used as a standard functional unit when applied, and can be interconnected with the navigation or flight control SiP system through gold wire bonding and welding through the fourth pad 206 on the top and the sixth pad 207 on the bottom of the special-shaped multi-cavity multi-layer wiring ceramic block 200.

[0049] In summary, the six-axis inertial sensing system-level packaging structure described in the present invention not only utilizes double-sided assembly of the ceramic substrate and embedded installation in the ceramic block to achieve high-density integration of the six-axis inertial sensing system, but also ensures the orthogonality of the six MEMS sensor units through the orthogonality between the mounting surfaces of the ceramic block, thereby achieving accurate sensing of three-dimensional space acceleration and angular velocity. While achieving high-performance and high-reliability packaging of MEMS sensor chips, sensor signal detection circuits, and data processing circuits, the present invention greatly reduces the packaging volume of the inertial sensing system, improves product performance, and reduces product costs, and can be used for navigation and flight control systems of small aircraft.

[0050] The above-described embodiments are merely descriptions of preferred implementations of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the scope of protection determined by the claims of the present invention.

Claims

1. An embedded six-axis inertial sensing system-level packaging structure, characterized in that: The packaging structure comprises a special-shaped multi-cavity multi-layer wiring ceramic block (200); the special-shaped multi-cavity multi-layer wiring ceramic block (200) is used to realize the integrated installation of a MEMS sensor unit (100) and a data processing circuit (204); The special-shaped multi-cavity multi-layer wiring ceramic block (200) comprises a ceramic block; a plurality of MEMS sensor units (100) are embedded and mounted on the ceramic block; a cavity unit for fixing the MEMS sensor unit (100) is opened on the ceramic block; the cavity unit comprises a first cavity (201) and a second cavity (208) respectively arranged at two ends of the top of the ceramic block, a third cavity (210) and a fourth cavity (211) respectively arranged at two ends of the front wall of the ceramic block, and a fifth cavity (202) arranged in the middle of the bottom of the ceramic block; a data processing circuit (204) installation area is arranged on the top of the ceramic block.

2. The embedded six-axis inertial sensing system-level packaging structure according to claim 1, characterized in that: A first groove (209) is provided in the middle of the front wall of the ceramic block, and the third cavity (210) and the fourth cavity (211) are located on both sides of the first groove (209); A second groove (212) is arranged at the middle position of the bottom of the ceramic block; and the fifth cavity (202) is arranged at the middle position of the second groove (212).

3. The embedded six-axis inertial sensing system-level packaging structure according to claim 1, characterized in that: The MEMS sensor unit (100) comprises a ceramic substrate having multi-layer wiring; A sensing signal detection circuit (101) and a first solder pad (103) are installed on the top of the ceramic substrate; the first solder pad (103) is used to be connected to the special-shaped multi-cavity multi-layer wiring ceramic block (200) by gold wire bonding; A MEMS sensor chip (102) and a second pad (104) are installed at the bottom of the ceramic substrate; the second pad (104) is used for welding and connecting with a special-shaped multi-cavity multi-layer wiring ceramic block (200).

4. The embedded six-axis inertial sensing system-level packaging structure according to claim 1, characterized in that: A third pad (203) and a fourth pad (206) are provided on the top of the ceramic block; the third pad (203) is used to interconnect with the MEMS sensor unit (100) by welding; and the fourth pad (206) is used to interconnect with an external navigation or flight control SiP system by gold wire bonding.

5. The embedded six-axis inertial sensing system-level packaging structure according to claim 2, characterized in that: A third groove (213) and a fourth groove (214) are respectively arranged on both sides of the second groove (212); a fifth pad (205) is arranged in each of the third groove (213) and the fourth groove (214); the fifth pad (205) is used to realize gold wire bonding interconnection with the MEMS sensor unit (100); and sixth pads (207) are respectively arranged at both ends of the bottom of the ceramic block; the sixth pad (207) is used to realize welding connection with an external navigation or flight control SiP system.

6. The embedded six-axis inertial sensing system-level packaging structure according to claim 1, characterized in that: The material of the ceramic block is Al2O3, and there are multiple layers of high-density wiring inside the ceramic block.

7. The embedded six-axis inertial sensing system-level packaging structure according to claim 1, characterized in that: A data processing circuit (204) is installed in the middle of the top of the ceramic block; The data processing circuit (204) adopts a silicon-based bare chip.

8. The embedded six-axis inertial sensing system-level packaging structure according to claim 1, characterized in that: The orthogonality between adjacent mounting surfaces of the special-shaped multi-cavity multi-layer wiring ceramic block (200) is 90°±0.1°, the flatness is ≤0.05mm, and the warpage is ≤50 / 25μm / mm.

9. The embedded six-axis inertial sensing system-level packaging structure according to claim 3, characterized in that: The material of the ceramic substrate is Al2O3; The sensor signal detection circuit (101) is fixed on the ceramic substrate by using a bare chip flip-chip welding process; The MEMS sensor chip (102) is fixed on the ceramic substrate by using a bonding process, and is electrically connected to the ceramic substrate by using a gold wire bonding process.

10. The method for assembling the embedded six-axis inertial sensing system-level packaging structure according to any one of claims 1 to 9, characterized in that: The method comprises the following steps: S1, an X-axis MEMS sensor unit and a Y-axis MEMS sensor unit are respectively mounted in a first cavity (201), a second cavity (208), a third cavity (210), and a fourth cavity (211) of a special-shaped multi-cavity multi-layer wiring ceramic block (200) by bonding, wherein a side of the MEMS sensor unit (100) on which the MEMS sensor chip (102) is mounted is embedded in the cavity and placed toward the inner side of the cavity, and a second pad (104) of the MEMS sensor unit (100) and a third pad (203) on the special-shaped multi-cavity multi-layer wiring ceramic block (200) are electrically connected by welding; S2. The Z-axis MEMS sensor unit is mounted in a fifth cavity (202) in the middle of the bottom of the special-shaped multi-cavity multi-layer wiring ceramic block (200) by bonding, wherein the side of the MEMS sensor unit (100) on which the MEMS sensor chip (102) is mounted is embedded in the fifth cavity and placed toward the inner side of the cavity, and the first pad (103) of the MEMS sensor unit (100) and the fifth pad (205) on the back side of the special-shaped multi-cavity multi-layer wiring ceramic block (200) are electrically connected by gold wire bonding.

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