Multi-channel weak signal detection system packaging structure suitable for three-dimensional installation

Abstract

The invention relates to a multi-channel weak signal detection system packaging structure suitable for three-dimensional installation. The packaging structure comprises a substrate. A first ring frame, a second ring frame and a first cover plate are sequentially arranged at the top of the base plate from bottom to top; a third ring frame is arranged at the bottom of the substrate; a second cover plate is arranged at the bottom of the third ring frame; the front side and the rear side of the substrate are respectively provided with a flange, and the left side and the right side of the substrate are respectively provided with a lead leg; the two flanges are located on the front side and the rear side of the third ring frame correspondingly. The two lead legs are located on the left side and the right side of the third ring frame respectively. According to the invention, a mixed micro-assembly process based on a bare chip is adopted, and double-sided assembly and high-reliability airtight packaging of components are realized. The top surface of the packaging structure is provided with three independent cavities, and weak signal detection circuits of three channels can be assembled respectively, so that inter-channel signal crosstalk and external signal interference caused by space electromagnetic radiation are reduced, and the detection precision of the circuits is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of three-dimensional system integrated packaging, and in particular to a multi-channel weak signal detection system packaging structure suitable for three-dimensional installation. Background Art

[0002] With the growing demand for military and civilian circuit systems, especially for weak signal detection systems, the requirements for integration, volume, accuracy and reliability of these systems are also increasing. Traditional weak signal detection circuits are usually manufactured based on printed circuit board (PCB) technology of plastic-encapsulated devices. However, in order to meet new requirements, hybrid integrated packaging structures based on bare chips have gradually developed, mainly including the following two types:

[0003] (1) Metal packaging

[0004] This package enables single-sided component assembly and uses a ceramic substrate inside. However, its disadvantages include the heavy weight of the metal housing and the fragile glass insulator used, which is prone to cracking.

[0005] (2) Ceramic packaging

[0006] This type of package can be a single-cavity or multi-cavity design, and also only supports the installation of components on one side. In addition, the production of multi-cavity ceramic bodies involves complex process flows, resulting in relatively low yields and difficult product maintenance. In addition, this type of package is not suitable for three-dimensional installation on system boards.

[0007] In general, although these two packaging methods have improved performance to a certain extent, they still face some challenges in practical applications, such as assembly restrictions, weight issues, material fragility, and production efficiency. Therefore, it is urgent to realize a multi-channel weak signal detection system packaging structure suitable for three-dimensional installation. Summary of the invention

[0008] The purpose of the present invention is to provide a multi-channel weak signal detection system packaging structure suitable for three-dimensional installation. The packaging structure can solve the deficiencies in the prior art. The packaging structure not only adopts a hybrid micro-assembly process based on bare chips to realize double-sided micro-assembly of components based on bare chips and high-reliability airtight packaging, but also effectively avoids signal crosstalk between channels and external signal interference caused by electromagnetic radiation in space, improves the detection accuracy of the circuit, and also realizes the overhead three-dimensional installation of the product on the system PCB board. The multi-channel weak signal detection system using this packaging structure has the characteristics of small size, high precision, flexible installation, etc.

[0009] To achieve the above object, the present invention adopts the following technical solutions:

[0010] A packaging structure of a multi-channel weak signal detection system suitable for three-dimensional installation, the packaging structure comprises a substrate. The top of the substrate is provided with a first ring frame, a second ring frame and a first cover plate in order from bottom to top; the bottom of the substrate is provided with a third ring frame; the bottom of the third ring frame is provided with a second cover plate; the front and rear sides of the substrate are respectively provided with a flange, and the left and right sides of the substrate are respectively provided with a lead leg; the two flanges are respectively located at the front and rear sides of the third ring frame; the two lead legs are respectively located at the left and right sides of the third ring frame.

[0011] The first ring frame and the second ring frame have the same structure, both comprising a frame and a plurality of partition plates arranged in the frame, and the frame is divided into a plurality of open cavities by the partition plates; the top of the substrate, the bottom of the first cover plate, the first ring frame and the second ring frame form a plurality of sealed first chambers; the bottom of the substrate, the third ring frame and the second cover plate form a sealed second chamber.

[0012] Furthermore, the first ring frame, the second ring frame, the third ring frame, the first cover plate, the second cover plate, the flange and the lead legs are all made of metal.

[0013] Furthermore, the first ring frame and the substrate, as well as the second ring frame and the first ring frame are welded by AgCu eutectic high-temperature brazing.

[0014] Furthermore, the first ring frame is made of oxygen-free copper, the second ring frame is made of kovar, the first cover plate is made of kovar, and the first cover plate and the second ring frame are sealed by parallel seam welding.

[0015] Furthermore, the substrate adopts a multi-layer high-temperature co-fired ceramic substrate; the multi-layer high-temperature co-fired ceramic substrate is formed by stacking multiple pieces of AlN raw ceramic sheets with surface wiring and then firing them at high temperature; the surface of the raw ceramic sheet is provided with a metal conductive tape, and the material of the metal conductive tape is W; metallized through holes are provided between different layers of metal conductive tapes of the substrate; and the metallized through holes are filled with W slurry.

[0016] Furthermore, a pad is provided on the surface of the substrate; the bottom layer of the pad is made of metal W, and the top layer is made of Ni and Au; the pad is used to weld components and the first ring frame and the third ring frame.

[0017] Furthermore, the number of wiring layers of the substrate is ≥10, and the pitch of the lead legs is ≤1.27 mm.

[0018] Furthermore, the first ring frame and the substrate, as well as the second ring frame and the first ring frame are welded together by AgCu eutectic high-temperature brazing to form a first chamber; the third ring frame is welded together with the substrate by AgCu eutectic high-temperature brazing; the second cover plate is made of oxygen-free copper and is sealed with the third ring frame by laser seam welding.

[0019] Furthermore, the lead leg is made of Kovar and is welded to the substrate using AgCu eutectic high-temperature brazing; the welding surface of the lead leg and the system PCB board protrudes 2mm from the sealing surface of the second cover plate.

[0020] Furthermore, the flange is made of Mo and is welded to the substrate by AgCu eutectic high-temperature brazing; the flange includes a longitudinal flange and a transverse flange arranged on one side of the top of the longitudinal flange; the transverse flange surface protrudes 2mm from the sealing surface of the second cover plate; a plurality of notches are provided on the longitudinal flange; and a plurality of semicircular through holes are provided on the transverse flange.

[0021] Compared with the prior art, the advantages of the present invention are:

[0022] The multi-channel weak signal detection system packaging structure suitable for three-dimensional installation of the present invention adopts a hybrid micro-assembly process based on bare chips to achieve double-sided assembly and high-reliability airtight packaging of components. The top surface of the packaging structure is provided with three independent chambers, and the weak signal detection circuits of the three channels can be assembled respectively to reduce the signal crosstalk between channels and external signal interference caused by spatial electromagnetic radiation, and improve the detection accuracy of the circuit. The flange is not only used to weld or bolt the product on the system PCB board, but also used as a heat dissipation channel of the product. The flange and the lead leg protrude 2mm from the bottom sealing surface, which can realize overhead installation on the system board. The overhead position can be used to install other components on the system PCB board to improve the assembly density of the system PCB board. Since the structure and the lead leg position of the package are axially symmetrical under the plane coordinate system, when the output signal is a fully differential signal, the differential signal processing circuit is distributed on the system PCB board at the bottom of the package, and the equal length, coplanar, parallel and short-distance routing of the differential signal line can be realized conveniently and quickly, avoiding the cross-layer and through-hole of the differential signal line when the system PCB board is double-sidedly assembled, which is conducive to maintaining signal integrity and avoiding signal reflection. The multi-channel weak signal detection system using this packaging structure has the characteristics of small size, high precision and flexible installation. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the packaging structure of the multi-channel weak signal detection system suitable for three-dimensional installation in the present invention. Figure 1 ;

[0024] Figure 2This is a schematic diagram of the packaging structure of the multi-channel weak signal detection system suitable for three-dimensional installation in the present invention. Figure 2 ;

[0025] Figure 3 This is a schematic diagram of the packaging structure of the multi-channel weak signal detection system suitable for three-dimensional installation in the present invention. Figure 3 ;

[0026] Figure 4 It is a schematic structural diagram of a multi-layer high-temperature co-fired ceramic substrate in the present invention.

[0027] in:

[0028] 100. substrate, 101. raw ceramic sheet, 102. metal conductive strip, 103. metal through hole, 104. pad, 200. first ring frame, 300. second ring frame, 400. third ring frame, 500. first cover plate, 600. second cover plate, 700. flange, 701. notch, 702. semicircular through hole, 800. lead leg, 900. first chamber, 1000. second chamber. DETAILED DESCRIPTION

[0029] The present invention will be further described below in conjunction with the accompanying drawings:

[0030] like Figure 1 and Figure 2 A packaging structure of a multi-channel weak signal detection system suitable for three-dimensional installation is shown, and the packaging structure includes a substrate 100; the top of the substrate 100 is provided with a first ring frame 200, a second ring frame 300 and a first cover plate 500 from bottom to top; the bottom of the substrate 100 is provided with a third ring frame 400; the bottom of the third ring frame 400 is provided with a second cover plate 600. A flange 700 is provided on the front and rear sides of the substrate 100, and a lead leg 800 is provided on the left and right sides of the substrate 100. The two flanges 700 are respectively located on the front and rear sides of the third ring frame 400. The two lead legs 800 are respectively located on the left and right sides of the third ring frame 400. The first ring frame 200 and the second ring frame 300 have the same structure, both including a frame and a plurality of partition plates arranged in the frame, and the frame is divided into a plurality of open cavities by the partition plates; the top of the substrate 100, the bottom of the first cover plate 500, the first ring frame 200 and the second ring frame 300 enclose a plurality of sealed first chambers 900. The bottom of the substrate 100 , the third ring frame 400 and the second cover plate 500 form a sealed second chamber 1000 .

[0031] Conventional multi-cavity ceramic substrates are formed by stacking layer by layer during the punching and isostatic pressing process in the green ceramic stage. Since components need to be assembled inside the cavity, the flatness of the bottom is required to be high, and the process control is difficult. In order to improve the structural strength, the ceramic partition wall between multiple cavities needs to have a certain thickness. In addition, ceramic is a non-electromagnetic shielding material, and the signal shielding effect is not good. According to the actual needs of the circuit, the present invention can flexibly process a multi-cavity ceramic metal integrated packaging shell structure that meets the needs of circuit electromagnetic shielding by welding metal ring frames of different shapes such as a square shape, a sun shape, a mesh shape, and a field shape on the top and bottom surfaces of a planar multi-layer ceramic substrate. The packaging structure described in the present invention is often used for weak signal detection of inertial sensors of three accelerometers or three gyroscopes in an inertial navigation system. Therefore, three chambers are set on the top of the substrate 100, each of which houses a weak signal detection circuit of an accelerometer or a gyroscope. The heads and tails of the three chambers are respectively located at the pins 800 on the left and right sides of the substrate 100. The weak signal enters the circuit in the chamber from the pin on one side, and the signal after circuit processing is output from the pin on the other side, thereby achieving the shortest transmission path for signal input and output to the pins and reducing external interference of the signal.

[0032] The packaging structure of a multi-channel weak signal detection system suitable for three-dimensional installation described in the present invention belongs to the field of three-dimensional system integrated packaging. The packaging structure is suitable for a multi-channel weak signal detection system and can realize double-sided high-density hybrid integrated micro-assembly based on bare chips. The three independent first chambers 900 on the top surface of the substrate 100 can respectively assemble the weak signal detection circuits of the three channels to reduce the signal crosstalk between the channels and the external signal interference generated by space radiation. The second chamber 1000 on the back of the substrate 100 is used to install the common circuit of the weak signal detection circuits of the three channels. The packaging structure described in the present invention adopts brazing, laser seam welding and parallel seam welding processes to achieve high-reliability airtight packaging. The flange 700 is not only used for mechanical fixation and heat dissipation of the product, but also can be used to install other components on the system PCB board by raising the product and overhead position, so as to realize the three-dimensional installation of the components of the system PCB board to improve the assembly density, and can conveniently and quickly realize the equal length, coplanar, parallel and short-distance routing of differential signals to maintain signal integrity. The present invention realizes high-performance and high-reliability packaging of a multi-channel weak signal detection circuit, greatly reduces the product volume, realizes three-dimensional installation on a system PCB board, and improves the flexibility of system layout and wiring and the assembly density of components.

[0033] Preferably, the packaging structure of the multi-channel weak signal detection system of the present invention has three independent first chambers 900 distributed on the top surface, and a second chamber 1000 is arranged on the bottom surface. The first chamber 900 is welded by a first ring frame 200 made of oxygen-free copper and a second ring frame 300 made of Kovar material with a multi-layer high-temperature co-fired ceramic substrate 100, and a first cover plate made of Kovar material is used to achieve airtight packaging through parallel seam welding. The three independent first chambers 900 on the top surface can be assembled with weak signal detection circuits of three channels to reduce signal crosstalk between channels and external signal interference caused by spatial electromagnetic radiation, and the second chamber 1000 on the bottom surface is installed with the circuit parts shared by the three channels.

[0034] Since the thermal expansion coefficient of the high temperature co-fired ceramic substrate 100 is about 4×10 -6 / ℃, the thermal expansion coefficient of the second ring frame 300 is about 5.5×10 -6 / ℃, if the two are directly welded, the ceramic substrate 100 will be subjected to excessive stress and cracked under high and low temperature environments due to the difference in thermal expansion coefficients. Therefore, the present invention uses the first ring frame 200 as a transition ring frame, and uses the good ductility and plasticity of oxygen-free copper to absorb and reduce the stress borne by the ceramic substrate 100, thereby improving the reliability of the packaging structure. In addition, due to the high thermal conductivity of oxygen-free copper, the heat during brazing is more easily transferred to the welding interface, which is conducive to the one-time brazing forming process of the high-temperature co-fired ceramic substrate 100 and the first ring frame 200, and the first ring frame 200 and the second ring frame 300, thereby improving the reliability and airtightness of the welding surface and the welding efficiency.

[0035] The multi-channel weak signal detection system packaging structure described in the present invention has a second chamber 1000 arranged on the bottom surface of the substrate 100. The second chamber 1000 is formed by welding a third ring frame 400 made of oxygen-free copper and a high-temperature co-fired ceramic substrate 100, and adopts a second cover plate 600 made of oxygen-free copper to achieve airtight packaging through laser seam welding.

[0036] Preferably, according to the present invention, the first ring frame 200, the second ring frame 300, the third ring frame 400, the first cover plate 500, the second cover plate 600, the flange 700 and the lead leg 800 are all made of metal. AgCu eutectic high-temperature brazing is used to achieve welding between the first ring frame 200 and the substrate 100, and the second ring frame 300 and the first ring frame 200. The welding surface has high air tightness and mechanical strength, and the residual stress is reduced by controlling the brazing cooling temperature and atmosphere. The material of the first cover plate 500 is Kovar, and it can be sealed with the second ring frame 300 by high-reliability parallel seam welding, which is convenient for product rework. The first ring frame 200 can effectively solve the problem of thermal expansion coefficient mismatch caused by direct welding of the substrate 100 and the second ring frame 300.

[0037] According to the preferred embodiment of the present invention, the substrate 100 is a multi-layer high-temperature co-fired ceramic substrate. The number of wiring layers of the multi-layer high-temperature co-fired ceramic substrate is ≥ 10 layers, and the lead leg pitch is ≤ 1.27 mm. Figure 4 As shown, the material of the multi-layer high-temperature co-fired ceramic substrate is AlN; the multi-layer high-temperature co-fired ceramic substrate is formed by stacking multiple pieces of raw ceramic sheets 101 of AlN material with surface wiring and then firing them at high temperature. The surface of the raw ceramic sheet 101 is provided with a metal conductive tape 102, and the material of the metal conductive tape 102 is W. Metallized through holes 103 are provided between different layers of conductive tapes of the multi-layer high-temperature co-fired ceramic substrate; the metallized through holes 103 are filled with W slurry. ALN greatly reduces the thermal resistance of the package and improves the detection accuracy and reliability of the chip and circuit by virtue of its high thermal conductivity and thermal expansion coefficient similar to that of silicon-based bare chips. By controlling the process parameters such as ALN powder casting, isostatic pressing, and sintering, the flexural strength of the substrate 100 reaches 400MPa and the surface flatness reaches 0.05mm to meet the requirements of micro-assembly.

[0038] like Figure 4 As shown, the surface of the multi-layer high-temperature co-fired ceramic substrate 100 is provided with a pad 104; the bottom layer material of the pad 104 is metal W, and the upper layer material is Ni and Au; the pad 104 is used to weld components and the first ring frame 200 and the third ring frame 400. AgCu eutectic high-temperature brazing is used to weld each ring frame, flange and multi-layer high-temperature co-fired ceramic substrate, providing a large temperature gradient space for the assembly of components.

[0039] like Figure 1 As shown, the first ring frame 200 and the second ring frame 300 are superimposed and welded to form three independent first chambers 900 on the top surface of the high-temperature co-fired ceramic substrate 100. After the components are assembled on the substrate 100 in the first chamber, the first cover plate 500 is used for high-reliability parallel seam welding and sealing. The first ring frame 200, the second ring frame 300 and the first cover plate 500 provide protection and support for the internal circuit, while greatly reducing the signal crosstalk between channels and external signal interference caused by electromagnetic radiation of the weak signal detection circuit assembled in each chamber, thereby improving the signal detection accuracy.

[0040] like Figure 1 As shown, the material of the first ring frame 200 is oxygen-free copper, and the material of the second ring frame 300 is kovar. The first ring frame 200 and the multi-layer high-temperature co-fired ceramic substrate 100, and the second ring frame 300 and the first ring frame 200 are connected by AgCu eutectic high-temperature brazing to form three independent chambers 900. Figure 2As shown, the third ring frame 400 is made of oxygen-free copper and is welded to the multi-layer high-temperature co-fired ceramic substrate 100 by AgCu eutectic high-temperature brazing. The second cover plate 600 is made of oxygen-free copper and can be laser seam welded to the third ring frame 400 .

[0041] Since the thermal expansion coefficient of the high temperature co-fired ceramic substrate 100 is about 4×10 -6 / ℃, the thermal expansion coefficient of the second ring frame 300 is about 5.5×10 -6 / ℃, if the two are directly welded, the ceramic substrate 100 will be subjected to excessive stress and cracked under high and low temperature environments due to the difference in thermal expansion coefficients. Therefore, the present invention uses the first ring frame 200 as a transition ring frame, and uses the good ductility and plasticity of oxygen-free copper to absorb and reduce the stress borne by the ceramic substrate 100, thereby improving the reliability of the packaging structure. In addition, due to the high thermal conductivity of oxygen-free copper, the heat during brazing is more easily transferred to the welding interface, which is conducive to the one-time brazing of the high-temperature co-fired ceramic substrate 100 and the first ring frame 200, and the first ring frame 200 and the second ring frame 300. By controlling the brazing cooling temperature and atmosphere to reduce residual stress, the reliability and airtightness of the welding surface are improved, and the welding efficiency is improved.

[0042] like Figure 1 and Figure 2 As shown, the lead leg 800 is made of Kovar and is welded to the multi-layer high temperature co-fired ceramic substrate 100 by AgCu eutectic high temperature brazing. Figure 3 As shown, the soldering surface of the lead leg 800 and the system PCB board protrudes 2mm from the sealing surface of the second cover plate 600, which can realize overhead installation on the system PCB board. The overhead position can be used to install other components on the system PCB board. The multi-channel weak signal detection system packaging structure described in the present invention is symmetrical in structure and lead leg position in a plane coordinate system. When the output signal is a fully differential signal, the differential signal processing circuit is distributed on the system PCB board at the bottom of the package, which can conveniently and quickly realize the equal length and shortest transmission distance of the differential signal line. At the same time, it can avoid the cross-layer and through-hole of the differential signal line when the system PCB board is assembled on both sides, which is conducive to maintaining signal integrity and avoiding signal reflection.

[0043] like Figure 2As shown, the material of the flange 700 is Mo, and AgCu eutectic high temperature brazing is used to achieve welding with the high temperature co-fired ceramic substrate 100. The flange 700 includes a longitudinal flange and a transverse flange arranged on one side of the top of the longitudinal flange; the transverse flange surface protrudes 2mm from the sealing surface of the second cover plate 600; a plurality of notches 701 are provided on the longitudinal flange; and a plurality of semicircular through holes 702 are provided on the transverse flange. The notches 701 can not only reduce the weight of the product, but also serve as stress buffer grooves to alleviate the large stress transfer to the metal ceramic welding part during installation and fixation, thereby improving the reliability of the packaging structure. The semicircular through holes 702 can be used to achieve bolt installation and fixation between the system board. The flange 700 is used to weld or bolt the product to the system board and act as a heat dissipation channel to quickly conduct the heat generated by the circuit to the system PCB board, reduce the temperature rise of the product, and improve the stability of the circuit parameters.

[0044] Since the lead pin 800 is thin and soft and can only be used for electrical connection, it cannot be used for mechanical fixation of the package structure. Therefore, a relatively strong metal flange 700 is welded on the bottom of the package structure. The flange 700 can not only be directly welded to the pad on the system PCB, but also can be bolted and fixed to the system PCB through the semicircular through hole 702 on the flange 700. In addition, the flange 700 can also serve as a heat dissipation channel to quickly conduct the heat generated by the circuit to the system PCB, reduce the temperature rise of the product, and improve the stability of the circuit parameters.

[0045] The multi-channel weak signal detection system packaging structure suitable for three-dimensional installation of the present invention can be directly welded or bolted to the system PCB board through the flange 700 when used; Figure 3 As shown, since there is a 2mm height difference between the lateral flange surface and the sealing surface of the second cover plate 600, when the packaging structure is installed on the system PCB board, there is a 2mm overhead height between the system PCB board and the sealing surface of the second cover plate 600. Components can be installed on the system PCB board at this overhead position to improve the assembly density of the system PCB board. The metal flange welded on the substrate is used to weld or bolt the product to the system PCB board, and also serves as a heat dissipation channel for the product, quickly transferring the heat generated by the circuit to the system PCB board, reducing the temperature rise of the product and improving the stability of the circuit parameters. Different from the board-level installation method of traditional component packaging, the flange and lead legs of the packaging structure protrude 2mm from the back sealing surface, which can realize the overhead installation of the product on the system PCB board. The overhead position can be used to install other components on the system PCB board to improve the assembly density of the system PCB board.

[0046] Since the package is axially symmetrical in structure and lead position in a plane coordinate system, when the lead output signal is a fully differential signal, the differential signal processing circuit is distributed on the system PCB board in an overhead position, which can conveniently and quickly realize equal-length, coplanar, parallel and short-distance routing of differential signal lines, avoiding crossing layers and passing through holes when the system PCB board is assembled on both sides, which is beneficial to maintaining signal integrity and avoiding signal reflection.

[0047] In summary, the present invention belongs to the field of three-dimensional system integrated packaging, and proposes a multi-channel weak signal detection system packaging structure suitable for three-dimensional installation. The packaging structure can realize double-sided high-density micro-assembly based on bare chips. The three independent chambers on the top surface can respectively assemble three-channel weak signal detection circuits to reduce the signal crosstalk between channels and external signal interference caused by space radiation. The bottom chamber is installed with the common circuit parts of the three channels. The two cover plates realize high-reliability airtight packaging. The flange is not only used for mechanical fixation and heat dissipation of the product, but also lifts the product to realize three-dimensional installation on the system PCB board. The present invention realizes high-performance and high-reliability packaging of multi-channel weak signal detection, while greatly reducing the packaging volume, and realizes three-dimensional installation on the system PCB board, thereby improving the assembly density of components of the system board.

[0048] 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. A multi-channel weak signal detection system packaging structure suitable for three-dimensional installation, characterized in that: The packaging structure comprises a substrate (100); The top of the base plate (100) is provided with a first ring frame (200), a second ring frame (300) and a first cover plate (500) in order from bottom to top; the bottom of the base plate (100) is provided with a third ring frame (400); the bottom of the third ring frame (400) is provided with a second cover plate (600); A flange (700) is provided on the front and rear sides of the base plate (100), and a lead leg (800) is provided on the left and right sides of the base plate (100); the two flanges (700) are respectively located on the front and rear sides of the third ring frame (400); the two lead legs (800) are respectively located on the left and right sides of the third ring frame (400); The first ring frame (200) and the second ring frame (300) have the same structure, both comprising a frame and a plurality of partition plates arranged in the frame, and the frame is divided into a plurality of open cavities by the partition plates; the top of the substrate (100), the bottom of the first cover plate (500), the first ring frame (200) and the second ring frame (300) form a plurality of sealed first chambers (900); the bottom of the substrate (100), the third ring frame (400) and the second cover plate (500) form a sealed second chamber (1000).

2. The multi-channel weak signal detection system packaging structure suitable for three-dimensional installation according to claim 1, characterized in that: The first ring frame (200), the second ring frame (300), the third ring frame (400), the first cover plate (500), the second cover plate (600), the flange (700) and the lead leg (800) are all made of metal.

3. The multi-channel weak signal detection system packaging structure suitable for three-dimensional installation according to claim 1, characterized in that: The first ring frame (200) and the substrate (100), as well as the second ring frame (300) and the first ring frame (200) are welded by AgCu eutectic high-temperature brazing.

4. The packaging structure of a multi-channel weak signal detection system suitable for three-dimensional installation according to claim 1, characterized in that: The first ring frame (200) is made of oxygen-free copper, the second ring frame (300) is made of kovar, the first cover plate (500) is made of kovar, and the first cover plate (500) and the second ring frame (300) are sealed by parallel seam welding.

5. The packaging structure of a multi-channel weak signal detection system suitable for three-dimensional installation according to claim 1, characterized in that: The substrate (100) is a multi-layer high-temperature co-fired ceramic substrate; the multi-layer high-temperature co-fired ceramic substrate is formed by stacking a plurality of raw ceramic sheets (101) made of AlN material with surface wiring and then firing them at high temperature; a metal conductive strip (102) is provided on the surface of the raw ceramic sheet (101), and the material of the metal conductive strip (102) is W; metallized through holes (103) are provided between different layers of metal conductive strips (102) of the substrate; and the metallized through holes (103) are filled with W slurry.

6. The multi-channel weak signal detection system packaging structure suitable for three-dimensional installation according to claim 1, characterized in that: A soldering pad (104) is provided on the surface of the substrate (100); the bottom layer material of the soldering pad (104) is metal W, and the top layer material is Ni and Au; the soldering pad (104) is used for soldering components and the first ring frame (200) and the third ring frame (400).

7. The multi-channel weak signal detection system packaging structure suitable for three-dimensional installation according to claim 1, characterized in that: The number of wiring layers of the substrate (100) is ≥10, and the pitch of the lead legs (800) is ≤1.27 mm.

8. The packaging structure of a multi-channel weak signal detection system suitable for three-dimensional installation according to claim 4, characterized in that: The first ring frame (200) and the substrate (100), as well as the second ring frame (300) and the first ring frame (200) are both connected by welding using AgCu eutectic high-temperature brazing to form a first chamber (900); the third ring frame (400) is connected by welding to the substrate (100) using AgCu eutectic high-temperature brazing; the second cover plate (600) is made of oxygen-free copper and is sealed with the third ring frame (400) by laser seam welding.

9. The packaging structure of a multi-channel weak signal detection system suitable for three-dimensional installation according to claim 4, characterized in that: The lead leg (800) is made of Kovar and is welded to the substrate (100) using AgCu eutectic high-temperature brazing; the welding surface of the lead leg (800) and the system PCB board protrudes 2 mm from the sealing surface of the second cover plate (600).

10. The multi-channel weak signal detection system packaging structure suitable for three-dimensional installation according to claim 1, characterized in that: The flange (700) is made of Mo and is welded to the substrate (100) by AgCu eutectic high-temperature brazing. The flange (700) comprises a longitudinal flange and a transverse flange arranged on one side of the top of the longitudinal flange; the transverse flange surface protrudes 2 mm from the sealing surface of the second cover plate (600); a plurality of notches (701) are provided on the longitudinal flange; and a plurality of semicircular through holes (702) are provided on the transverse flange.

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