Lightweight high-thermal-conductivity graphene-aluminum gradient packaging tube shell and design method thereof

Abstract

The invention provides a light high-thermal-conductivity graphene-aluminum gradient packaging tube shell and a design method thereof, the light high-thermal-conductivity graphene-aluminum gradient packaging tube shell comprises a tube shell base, a tube shell frame, a connector opening, a seal welding port and a packaging cover plate, the tube shell base is welded with the tube shell frame through vacuum brazing, and the packaging cover plate and the seal welding port are packaged to obtain the packaging tube shell; the tube shell base is made of a first gradient material, the tube shell frame is made of a second gradient material, the second gradient material and the packaging cover plate are made of aluminum alloy materials, the first gradient material contains metal components the same as the second gradient material and the packaging cover plate, and the first gradient material comprises graphene. The graphene and the aluminum alloy are compounded by utilizing the characteristics of high strength, easiness in processing, easiness in coating and the like of the aluminum alloy, and the gradient design and the airtight packaging design of a tube shell material are carried out by matching thermal performance simulation and a packaging process, so that the application and packaging requirements of light weight and high heat conductivity are met; and the high-power microwave assembly can work permanently and reliably.

Description

Technical Field

[0001] The present invention relates to the technical field of electrical components, and in particular to a lightweight and highly thermally conductive graphene-aluminum gradient packaging tube shell and a design method thereof. Background Art

[0002] With the development of miniaturization and high integration of electronic equipment, electronic chips are constantly developing towards high performance, high speed and high integration. The use of high-power chips leads to excessively high local temperatures of component products, which can easily lead to device failure. In order to avoid excessive local temperatures, high thermal conductivity heat expansion materials are needed to quickly convert the excessively high point heat source into a surface heat source.

[0003] However, the existing chip packaging tube and shell structural materials generally have the bottleneck problem of "one heavy and two lows" (high density, low thermal conductivity, and low thermal radiation coefficient). For example, the copper alloy tube and shell and the diamond copper tube and shell developed in recent years have high thermal conductivity but too high density, and the aluminum alloy, silicon aluminum alloy and aluminum-based silicon carbide tube and shell have low density but lower thermal conductivity than copper alloy. They cannot meet the needs of fast heat transfer of small-volume and high-power electronic devices.

[0004] Therefore, it is necessary to accelerate the upgrading of traditional materials, use high-strength and high-conductivity materials, combine with advanced packaging technology, design and develop lighter and more thermally conductive packaging shells, so as to achieve the integration of microwave component packaging shell heat dissipation / load-bearing functions and micro-assembly process integration. Summary of the invention

[0005] The present invention aims to solve the problems that the density and thermal conductivity of the existing packaging tube shell cannot be positively matched, graphene-aluminum has not been industrially applied in micro-assembly packaging, and high performance lacks effective combination with micro-assembly reflow soldering and airtight packaging. A lightweight and high thermal conductivity graphene-aluminum gradient packaging tube shell and a design method thereof are provided. Graphene and aluminum alloy are compounded by utilizing the high strength, easy processing and easy coating of aluminum alloy, and the tube shell material gradient design and airtight packaging design are carried out by matching thermal performance simulation with packaging process, which meets the requirements of lightweight, high thermal conductivity use and packaging while ensuring that high-power microwave components can work long-term and reliably.

[0006] The present invention provides a lightweight and highly thermally conductive graphene-aluminum gradient package tube shell, comprising a tube shell base welded to a printed circuit board and conducting heat, a tube shell frame connected to the tube shell base around the tube shell base, a connector opening connected to the tube shell frame, a sealing welding port connected to the top of the tube shell frame, and a packaging cover plate welded to the tube shell frame through the sealing welding port. The tube shell base is welded to the tube shell frame through vacuum brazing to form an integrated component, and the packaging cover plate and the sealing welding port are packaged to obtain a package tube shell;

[0007] The tube shell base uses a first gradient material, the tube shell frame uses a second gradient material, the second gradient material and the package cover plate are both alloy materials, the first gradient material contains the same metal component as the second gradient material and the package cover plate material, and the first gradient material includes graphene;

[0008] The thermal conductivity of the shell base is greater than that of aluminum alloy and copper alloy and greater than that of the shell frame. The density of the shell base is less than that of the diamond substrate composite material. The density of the shell base is less than 3g / cm 3 ;

[0009] The printed circuit board welding surface of the tube shell base is used for reflow oven welding with the printed circuit board.

[0010] The lightweight and highly thermally conductive graphene-aluminum gradient packaging tube shell described in the present invention is, as a preferred embodiment, the first gradient material is a graphene-aluminum composite material, the second gradient material is aluminum alloy 6061, the material of the packaging cover plate is aluminum alloy 4047, and the packaging cover plate and the sealing port are sealed and connected by laser sealing.

[0011] The lightweight and highly thermally conductive graphene-aluminum gradient packaging tube shell described in the present invention is, as a preferred embodiment, a graphene-aluminum composite material that is a sandwich material of an aluminum-graphene-aluminum structure, and the thermal conductivity of the graphene-aluminum composite material is greater than 650W / mK.

[0012] The lightweight and highly thermally conductive graphene-aluminum gradient package tube shell described in the present invention is preferably provided with threaded holes on the tube shell base and the tube shell frame;

[0013] The soldering surface of the printed circuit board is gold-plated, the inner surface of the connector opening is gold-plated for reflow oven soldering, and the sealing port is subjected to natural color conductive oxidation treatment.

[0014] The lightweight and highly thermally conductive graphene-aluminum gradient packaging tube shell described in the present invention is preferably treated with gold plating of Al / Ap.Ni3~5Ep.Au0.2~0.5 on the welding surface of the printed circuit board and the inner surface of the connector opening, and treated with Al / Ct.Ocd for natural color conductive oxidation.

[0015] The lightweight and highly thermally conductive graphene-aluminum gradient package tube shell of the present invention is preferably a tube shell base including a tube shell base body, fixed ribs connected to the upper surface of the tube shell base body, a printed circuit board welding surface, and grooves and bosses connected to the base body. The tube shell base body is a plate-like structure, and a threaded hole is connected to the tube shell base body.

[0016] The connector openings include pin header socket mounting holes, grounding column mounting holes, SMP mounting holes, glass bead mounting holes and through-core capacitor mounting holes.

[0017] The lightweight and highly thermally conductive graphene-aluminum gradient packaging tube shell described in the present invention is preferably configured such that the thickness of the tube shell frame is uneven, and the wall thickness at the SMP mounting hole is greater than the wall thickness at the glass bead mounting hole.

[0018] The lightweight and highly thermally conductive graphene-aluminum gradient packaging tube shell described in the present invention is, as a preferred embodiment, a tube shell base with a thickness of 1.5 to 4 mm, a tube shell frame size less than 100×100 mm, a thickness of 1.5 to 5 mm, and a height greater than 3 mm.

[0019] The present invention provides a design method for a lightweight and highly thermally conductive graphene-aluminum gradient packaging tube shell, comprising the following steps:

[0020] S1. Material design is performed. The material of the tube shell base is set to be a graphene-aluminum composite material with surface metallization, and the tube shell frame is set to be an aluminum alloy material. The aluminum material shared by the tube shell base and the tube shell frame improves the adhesion, uniformity and thermal matching of the solder during the welding process of the tube shell base and the tube shell frame. The package cover is set to be an aluminum alloy material with a higher density than the tube shell frame;

[0021] S2. Simulate and design the thickness of the tube shell base, and use simulation software to perform thermal management layout and simulation according to the heat consumption distribution of the heating device of the designed microwave component and the working environment conditions. The laying area and thickness of the graphene-aluminum in the tube shell base can be iteratively optimized and adjusted according to the simulation results;

[0022] S3. To meet the airtight design, the tube shell frame is set to aluminum alloy 6061, and the package cover is set to aluminum alloy 4047;

[0023] The upper end face of the tube shell frame is laser sealed with aluminum alloy 4047, and the lower end face is vacuum brazed with the tube shell base. They are all welded between aluminum alloys with consistent thermal matching.

[0024] S4. The wall thickness of the tube shell frame is at least 1.5mm and the connector opening is designed. The height of the tube shell frame is adjusted according to the height of the components inside the assembly and the height requirements of the connector;

[0025] S5. According to the internal structure of the microwave product, bosses, partitions, grooves, threaded mounting holes, and welding socket mounting holes are arranged on the printed circuit board welding surface of the tube shell base;

[0026] S6. The metal surface treatment method of the constrained gradient package shell is that the shell base is treated by a surface treatment method combining local gold plating and natural conductive oxidation, which can partially realize the 130℃ ~ 280℃ reflow oven soldering process. The sealing port is treated by natural conductive oxidation (Al / Ct.Ocd (natural color)) to meet the requirements of high-intensity laser beam directly radiating to the surface of the sealing port material to achieve the sealing of the package shell. A design method for a lightweight and high thermal conductivity graphene-aluminum gradient package shell is completed.

[0027] The design method of a lightweight and highly thermally conductive graphene-aluminum gradient packaging tube shell described in the present invention is, as a preferred embodiment, in step S1, the graphene-aluminum composite material is a sandwich material of an aluminum-graphene-aluminum structure;

[0028] In step S2, ANSYS simulation software is used to perform thermal management layout and simulation;

[0029] In step S4, the thickness of the tube shell frame is uneven;

[0030] In step S5, the grooves and non-connector holes are all blind grooves and blind holes and cannot be punched through to ensure mechanical strength;

[0031] In step S6, the soldering surface of the printed circuit board and the inner surface of the connector opening are both gold-plated to achieve a 130° C. to 280° C. reflow oven soldering process, and the non-reflow soldering area of ​​the tube shell base is subjected to a natural color conductive oxidation treatment.

[0032] The present invention utilizes the high thermal conductivity of graphene combined with the good mechanical properties of aluminum alloy, and through material gradient design and airtight packaging design, efficiently realizes the lightweight, thermal management and micro-assembly packaging design requirements of microwave high-power components.

[0033] The present invention is achieved through the following technical solutions:

[0034] A lightweight, high-thermal-conductivity graphene-aluminum gradient package tube shell and a design method thereof, wherein the gradient package tube shell is used to assemble microwave printed circuit boards, power bare chips, gold-plated connectors, etc., and the assembly method can be screw connection, reflow soldering, laser sealing, etc. The gradient tube shell is composed of two levels of gradient materials, the first gradient material is a graphene-aluminum composite material, designed as a sandwich composite form, as a package tube shell base, the second gradient material is an aluminum alloy 6061 material, as a package tube shell frame, and the first gradient and the second gradient materials are formed by vacuum brazing welding to form a package tube shell.

[0035] The principle of the above scheme is: first, using high thermal conductivity graphene-aluminum composite material as the tube shell base, its thermal conductivity can reach more than 650W / mK, which is much higher than traditional metal materials such as aluminum alloy, copper alloy and composite materials such as silicon aluminum. It can quickly convert the point heat source of small volume and high power electronic chip into surface heat source to meet the needs of uniform temperature and rapid heat transfer; secondly, its density can generally be controlled at 2.2~2.6g / cm 3It is much lower than the diamond-based composite material with the same high thermal conductivity, which meets the demand for lightweight. At the same time, the upper frame of the tube shell is made of 6061 aluminum alloy, and the upper end is matched with the aluminum alloy 4047 packaging cover material to meet the laser sealing and micro-assembly packaging requirements. The lower end and the base are vacuum brazed to form an integrated tube shell to meet the airtight design requirements. The welding table, holes and other features are reasonably arranged inside the tube shell, and the bottom surface of the cavity and the inner surface of the connector opening need to be gold-plated to achieve micro-assembly welding of printed circuit boards, chips, and connectors.

[0036] The present invention has the following advantages:

[0037] (1) Existing packaging shell design methods are mostly based on the packaging of traditional metal materials, such as aluminum alloy, silicon aluminum alloy, copper alloy and other materials. As the heat generation and relative heat flow of electronic components are getting higher and higher, they can no longer meet the demand for rapid heat dissipation, which directly affects the reliability and life of the components. The present invention can overcome this shortcoming. The proposed graphene-aluminum shell not only utilizes the high thermal conductivity of graphene, but also utilizes the high strength, easy processing and easy coating characteristics of lightweight aluminum alloy. While achieving performance indicators such as light weight and high thermal conductivity, it can also achieve seamless replacement with the packaging shell of existing electronic equipment.

[0038] (2) The graphene-aluminum composite micro-assembly airtight packaging design that has been developed is rarely used. The packaging tube shell proposed in the present invention is designed with gradient materials, which is convenient for mechanical processing and can meet the requirements of micro-assembly process and airtight packaging, solving the problem of integrating the heat dissipation and load-bearing functions of the microwave component packaging shell and the process integration.

[0039] (3) The present invention is universal and can be applied to thermal management and packaging design of various high-power components by adjusting the thickness and position layout of graphene-aluminum materials and superimposing simulation iterative optimization. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A schematic diagram of the structure of a lightweight and highly thermally conductive graphene-aluminum gradient packaging tube shell without a packaging cover plate installed;

[0041] Figure 2 It is a schematic diagram of the cross-sectional structure of a lightweight and highly thermally conductive graphene-aluminum gradient packaging tube shell;

[0042] Figure 3 A cross-sectional view of a lightweight and highly thermally conductive graphene-aluminum gradient package tube shell without a package cover installed along the axial direction of a connector hole;

[0043] Figure 4 A top view of a lightweight and highly thermally conductive graphene-aluminum gradient packaging tube shell without a packaging cover plate installed;

[0044] Figure 5A left view of a lightweight and highly thermally conductive graphene-aluminum gradient packaging tube shell without a packaging cover plate installed;

[0045] Figure 6 A right view of a lightweight and highly thermally conductive graphene-aluminum gradient packaging tube shell without a packaging cover plate installed;

[0046] Figure 7 A top view of a lightweight and highly thermally conductive graphene-aluminum gradient packaging tube shell without a packaging cover plate installed;

[0047] Figure 8 A schematic diagram of a printed circuit board welding surface of a lightweight and highly thermally conductive graphene-aluminum gradient packaging tube shell;

[0048] Fig. 9 A schematic diagram of the left gold-plated area of ​​a lightweight and highly thermally conductive graphene-aluminum gradient packaging tube shell without a packaging cover plate installed;

[0049] Fig.10 A schematic diagram of the right gold-plated area of ​​a lightweight and highly thermally conductive graphene-aluminum gradient packaging tube shell without a packaging cover plate installed;

[0050] Fig.11 A schematic diagram of the bottom gold-plated area of ​​a lightweight and highly thermally conductive graphene-aluminum gradient packaging tube shell without a packaging cover plate installed;

[0051] Fig.12 A flow chart of a design method for a lightweight and highly thermally conductive graphene-aluminum gradient packaging tube shell;

[0052] Fig.13 Schematic diagram of simulation results before using graphene-aluminum;

[0053] Fig.14 The simulation results of a lightweight and high thermal conductivity graphene-aluminum gradient packaging tube shell and its design method using graphene-aluminum are presented.

[0054] Reference numerals:

[0055] 1. Shell base; 11. Shell base body; 12. Fixed ribs; 13. PCB welding surface; 2. Shell frame; 3. Connector opening; 31. Pin header and socket mounting hole; 32. Grounding column mounting hole; 33. SMP mounting hole; 34. Glass bead mounting hole; 35. Through-core capacitor mounting hole; 4. Sealing port; 5. Package cover; 6. Threaded hole. DETAILED DESCRIPTION

[0056] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0057] Example 1

[0058] A lightweight and highly thermally conductive graphene-aluminum gradient packaging tube shell and a design method thereof, such as Figures 1 to 11 As shown, the gradient package tube shell of the present invention, i.e., the basic form of the present invention, is composed of a tube shell base 1, a tube shell frame 2, a connector opening 3, a sealing port 4, a package cover plate 5 and a threaded hole 6. The tube shell base 1 and the tube shell frame 2 are welded into an integrated component by vacuum brazing, and a connector opening 3 matching the connector is processed on the side wall of the frame.

[0059] The material selected for the shell base 1 is a graphene-aluminum composite material. The thickness of the base can be appropriately adjusted according to the total height, heat dissipation and weight requirements of the product. The commonly used thickness is 1.5-4 mm. The shell base 1 can be designed with threaded holes, grooves, bosses and other processing features to meet the actual assembly requirements of microwave components. The printed circuit board welding surface 13 should be gold-plated to achieve a 130°C-280°C reflow oven welding process.

[0060] The material selected for the tube shell frame 2 is 6061 aluminum alloy. The frame dimensions are generally not more than 100X100mm, and the frame wall thickness is generally 1.5-5mm. This size can be adjusted according to design requirements. The frame height is generally greater than 3mm, and this size can be flexibly adjusted according to the height requirements of components.

[0061] The shell frame 2 is generally designed with a connector opening 3, such as glass bead 34, SMP33, J30J rectangular sealed sockets, etc., and the inner surface of the connector opening 3 needs to be gold-plated to achieve a 130°C to 280°C reflow oven soldering process. The upper end sealing port 4 of the shell frame 2 is generally not gold-plated to meet the requirements of the laser sealing process, and is only subjected to a natural color conductive oxidation treatment.

[0062] like Fig.12 As shown, a method for designing a lightweight and highly thermally conductive graphene / aluminum gradient packaging shell includes the following steps:

[0063] Step 1, the material of the gradient packaging tube shell base 1 is a graphene-aluminum composite material. As the first gradient material, the composite material is designed in a sandwich form, that is, an aluminum-graphene-aluminum structure. The purpose of this design is to metallize the graphene surface, increase the adhesion and uniformity of the solder during the welding process, and have high thermal matching consistency with the subsequent tube shell frame.

[0064] Step 2: Simulate and design the thickness of the gradient package shell base 1, and use simulation software such as ANSYS to perform thermal management layout and simulation according to the heat consumption distribution of the heating device of the designed microwave component and the working environment conditions. The laying area and thickness of the graphene-aluminum in the shell base 1 can be iteratively optimized and adjusted according to the simulation results.

[0065] Step three, the material of the gradient packaging frame 2 is aluminum alloy 6061, which is used as the second gradient material. This selection is to meet the airtightness design of the tube shell. The upper end face of the packaging frame 2 is laser-sealed with aluminum alloy 4047, and the lower end face is vacuum-brazed with the tube shell base 1. Both are welded between aluminum alloys, with consistent thermal matching, easy adjustment of molding process parameters, small welding residual stress, small thermal deformation, and easy maintenance of the overall configuration of the integrated packaging tube shell.

[0066] Step 4: The wall thickness of the frame 2 is at least 1.5 mm and can be uneven. A connector opening 3 is generally designed on the tube shell frame 2. Such connectors include glass beads, SMP, J30J rectangular sealed sockets, etc. The height of the tube shell frame 2 can be flexibly adjusted according to the height of the components inside the assembly and the height requirements of the connectors.

[0067] Step 5. According to the internal structure of the actual microwave product, it is difficult to design the printed circuit board welding surface 13 of the gradient package tube shell base 1 into a complete plane. Generally, it is necessary to arrange features such as bosses, partitions, grooves, threaded mounting holes, welding socket mounting holes, etc. The design of such features fully considers the number and layout of printed circuit boards inside the component product, the installation methods of all printed circuit boards and components, and the matching height requirements of the mounting surface, and meets the sealing of the tube shell, that is, the groove features and non-connector hole features are all blind slots and blind holes, which cannot be pierced and ensure mechanical strength.

[0068] Step 6: Constrain the metal surface treatment method of the gradient package shell. The gradient package shell is suitable for packaging by reflow soldering and laser capping. Therefore, it is recommended that the package shell adopts a surface treatment method combining local gold plating (Al / Ap.Ni3~5Ep.Au0.2~0.5) and natural color conductive oxidation (Al / Ct.Ocd (natural color)), that is, the printed circuit board welding surface 13 and the inner surface of the connector opening 3 should be gold-plated (Al / Ap.Ni3~5Ep.Au0.2~0.5). 5) Treatment is used to realize the 130℃~280℃ reflow furnace soldering process. The other non-reflow soldering areas are treated with natural color conductive oxidation (Al / Ct.Ocd (natural color)), and the laser sealing welding area on the upper end of the tube shell can only be treated with natural color conductive oxidation (Al / Ct.Ocd (natural color)). Gold plating is not allowed to appear, so that the high-intensity laser beam is directly radiated to the surface of the tube shell weld material without laser reflection. Through the interaction between the laser and the material, the material is melted and welded to achieve product sealing.

[0069] like Figures 3 to 11 As shown, an example of a graphene-aluminum gradient packaging shell, the shell area range is limited to no more than 65mm*20mm.

[0070] The shell design is based on the material properties of the selected graphene-aluminum. The thermal conductivity of graphene-aluminum is set to 800W / mK. According to the thermal power layout and heat dissipation requirements of the sample product, the height of the device in the shell and the RF performance requirements are considered through thermal simulation analysis iterations. The shell graphene / aluminum bottom thickness H2 is determined to be 3.45mm, and the shell height H1 is determined to be 9.5mm, that is, the outer contour of the shell is formed. The bottom surface is a graphene-aluminum composite material, and the shell frame material is aluminum alloy 6061. For thermal simulation comparisons, Fig.13 , 14 As shown, the maximum simulation temperature using pure 6061 aluminum shell is 76.17°C, and the shell temperature rises by 16.17°C; the maximum simulation temperature using graphene-aluminum gradient shell is 68.04°C, and the shell temperature rises by only 8.04°C, with a temperature rise optimization of 50%.

[0071] When designing the interior of the tube shell, the shape of the printed circuit board and the installation space of the electronic components are considered, and the fixed rib feature 12 in the tube shell cavity is determined. Since the product requires two layers of cover plates, the first layer is laser-sealed and the second layer is screwed, threaded hole features 6 are arranged on the upper surface of the fixed rib feature 13 in the tube shell cavity to meet the requirements of screwing the cover plate for installation;

[0072] According to the type and size of the external connector of the product, the pin header and socket mounting hole features 31, the grounding column mounting hole features 32, the SMP mounting hole features 33, the glass bead mounting hole features 34, the through-core capacitor mounting hole features 35, etc. are arranged on the side wall of the tube shell frame respectively. At the same time, the local wall thickness of the tube shell is determined according to the thickness of the connector and the requirements of the welding opening. For example, the shell wall thickness L1 at the SMP of the tube shell is 4.15mm, and the shell wall thickness L2 at the glass bead is 2.2mm.

[0073] Finally, the shell adopts the surface treatment form of partial gold plating, that is, natural color conductive oxide +

[0074] Some areas are gold plated, e.g. Fig.14 The shadow shown is the gold-plated layer area 13, and the surface treatment method is Al / Ap.Ni3~5Ep.Au0.2~0.5. The other areas are all Al / Ct.Ocd (natural color), which is used to realize 130℃~280℃ reflow furnace welding process and laser sealing welding process.

[0075] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A lightweight and highly thermally conductive graphene-aluminum gradient packaging tube shell, characterized in that: The invention comprises a tube shell base (1) welded to a printed circuit board and conducting heat, a tube shell frame (2) connected around the tube shell base (1), a connector opening (3) connected to the tube shell frame (2), a sealing welding port (4) connected to the top of the tube shell frame (2), and a packaging cover plate (5) welded to the tube shell frame (2) through the sealing welding port (4), wherein the tube shell base (1) is welded to the tube shell frame (2) by vacuum brazing to form an integrated component, and the packaging cover plate (5) is packaged with the sealing welding port (4) to obtain a packaged tube shell; The tube shell base (1) uses a first gradient material, the tube shell frame (2) uses a second gradient material, the second gradient material and the packaging cover plate (5) are both made of aluminum alloy, the first gradient material contains the same metal component as the second gradient material and the packaging cover plate (5), and the first gradient material includes graphene; The thermal conductivity of the tube shell base (1) is greater than that of aluminum alloy and copper alloy and greater than that of the tube shell frame (2); the density of the tube shell base (1) is less than that of the diamond substrate composite material; the density of the tube shell base (1) is less than 3 g / cm 3 ; The printed circuit board welding surface of the tube shell base (1) is used for reflow furnace welding with the printed circuit board.

2. The lightweight and highly thermally conductive graphene-aluminum gradient packaging tube shell according to claim 1, characterized in that: The first gradient material is a graphene-aluminum composite material, the second gradient material is aluminum alloy 6061, the material of the packaging cover plate (5) is aluminum alloy 4047, and the packaging cover plate (5) and the sealing port (4) are sealed and connected by laser sealing.

3. The lightweight and highly thermally conductive graphene-aluminum gradient packaging tube shell according to claim 2, characterized in that: The graphene-aluminum composite material is a sandwich material of an aluminum-graphene-aluminum structure, and the thermal conductivity of the graphene-aluminum composite material is greater than 650 W / mK.

4. The lightweight and highly thermally conductive graphene-aluminum gradient packaging tube shell according to claim 1, characterized in that: The tube shell base (1) and the tube shell frame (2) are both provided with threaded holes (6); The soldering surface of the printed circuit board is plated with gold, the inner surface of the connector opening (3) is plated with gold for soldering in a reflow furnace, and the sealing solder port (4) is subjected to a natural color conductive oxidation treatment.

5. The lightweight and highly thermally conductive graphene-aluminum gradient packaging tube shell according to claim 4, characterized in that: The soldering surface of the printed circuit board and the inner surface of the connector opening (3) are gold-plated to Al / Ap.Ni3-5Ep.Au0.2-0.5, and the natural color conductive oxidation treatment is Al / Ct.Ocd.

6. The lightweight and highly thermally conductive graphene-aluminum gradient packaging tube shell according to claim 4, characterized in that: The tube shell base (1) comprises a tube shell base body (11), a fixed rib (12) connected to the upper surface of the tube shell base body (11), the printed circuit board welding surface (13), and a groove and a boss connected to the base body (11); the tube shell base body (11) is a plate-like structure, and the tube shell base body (11) is connected to the threaded hole (6); The connector opening (3) comprises a pin header socket mounting hole (31), a grounding column mounting hole (32), an SMP mounting hole (33), a glass bead mounting hole (34) and a through-core capacitor mounting hole (35).

7. The lightweight and highly thermally conductive graphene-aluminum gradient packaging tube shell according to claim 6, characterized in that: The thickness of the tube shell frame (2) is uneven, and the wall thickness at the SMP mounting hole (33) is greater than the wall thickness at the glass bead mounting hole (34).

8. The lightweight and highly thermally conductive graphene-aluminum gradient packaging tube shell according to claim 1, characterized in that: The tube shell base (1) has a thickness of 1.5 to 4 mm, and the tube shell frame (2) has a size less than 100×100 mm, a thickness of 1.5 to 5 mm, and a height greater than 3 mm.

9. A method for designing a lightweight and highly thermally conductive graphene-aluminum gradient packaging tube shell according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1. Material design is performed. The material of the tube shell base (1) is set to be a graphene-aluminum composite material with a metalized surface. The tube shell frame (2) is set to be an aluminum alloy material. The aluminum material shared by the tube shell base (1) and the tube shell frame (2) improves the adhesion, uniformity and thermal matching of the solder during the welding process of the tube shell base (1) and the tube shell frame (2). The packaging cover plate (5) is set to be an aluminum alloy material with a higher density than that of the tube shell frame (2); S2, the thickness of the tube shell base (1) is simulated and designed, and the thermal management layout and simulation are performed using simulation software according to the heat consumption distribution of the heating device of the designed microwave component and the working environment conditions. The laying area and thickness of the graphene-aluminum in the tube shell base (1) can be iteratively optimized and adjusted according to the simulation results; S3. To meet the requirements of airtightness design, the tube shell frame (2) is made of aluminum alloy 6061, and the packaging cover plate (5) is made of aluminum alloy 4047; The upper end surface of the tube shell frame (2) is laser-sealed with aluminum alloy 4047, and the lower end surface is vacuum-brazed with the tube shell base (1), both of which are welded between aluminum alloys with consistent thermal matching; S4, the wall thickness of the tube shell frame (2) is at least 1.5 mm and the connector opening (3) is designed, and the height of the tube shell frame (2) is adjusted according to the height requirements of the components inside the assembly and the height requirements of the connector; S5. Arrange bosses, partition walls, grooves, threaded mounting holes (6), and welding socket mounting holes on the printed circuit board welding surface (13) of the tube shell base (1) according to the internal structure of the microwave product; S6. The metal surface treatment method of the gradient packaging shell is constrained. The shell base (1) uses a surface treatment method combining local gold plating and natural conductive oxidation, which can locally realize a 130°C to 280°C reflow oven soldering process. The sealing port (4) uses natural conductive oxidation (Al / Ct.Ocd (natural color)) treatment to meet the requirements of high-intensity laser beam directly radiating to the surface of the sealing port (4) material, thereby realizing the sealing of the packaging shell. A design method for a lightweight and high thermal conductivity graphene-aluminum gradient packaging shell is completed.

10. The design method of a lightweight and highly thermally conductive graphene-aluminum gradient packaging tube shell according to claim 9, characterized in that: In step S1, the graphene-aluminum composite material is a sandwich material of aluminum-graphene-aluminum structure; In step S2, ANSYS simulation software is used to perform thermal management layout and simulation; In step S4, the thickness of the tube shell frame (2) is uneven; In step S5, the grooves and non-connector holes are all blind grooves and blind holes and cannot be punched through to ensure mechanical strength; In step S6, the printed circuit board welding surface (13) and the inner surface of the connector opening (3) are both gold-plated to achieve a 130°C to 280°C reflow furnace welding process, and the non-reflow welding area of ​​the tube shell base (1) is subjected to a natural color conductive oxidation treatment.

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