Shielding cover, circuit board support, electronic equipment and preparation method of structural member

Abstract

The invention provides a shielding case, a circuit board support, electronic equipment and a preparation method of a structural member. The shielding cover comprises a cover body and a flange, the flange is fixedly connected to the periphery of the cover body, the cover body and the flange are an integrally-formed structural part, the cover body and the flange are both made of metal materials, the material density of the flange is larger than that of the cover body, and the wetting angle of the solder paste on the surface of the flange is smaller than that of the solder paste on the surface of the cover body. Therefore, when the shielding case meets the requirement of light weight and the flanges are fixedly connected with other structural members in a welding manner, the connection strength is relatively good.

Description

Technical Field

[0001] The present application relates to the technical field of terminal equipment, and in particular to a method for preparing a shielding cover, a circuit board bracket, an electronic device and a structural member. Background Art

[0002] In order to meet the demand for lightweight, the internal structural parts of electronic equipment are usually made of lightweight materials. However, when these structural parts are connected to other structural parts, the connection strength of the connection structure between the two is poor, which makes it difficult to meet the demand for connection reliability. Summary of the invention

[0003] The present application provides a method for preparing a shielding cover, a circuit board bracket, an electronic device and a structural member.

[0004] In a first aspect, an embodiment of the present application provides a shielding cover. The shielding cover is applied to an electronic device. The shielding cover includes a cover body and a flange, the flange is fixedly connected to the periphery of the cover body, the cover body and the flange are integrally formed structural parts, the cover body and the flange are both made of metal material, and the material density of the flange is greater than the material density of the cover body, and the wetting angle of the solder paste on the surface of the flange is less than the wetting angle of the solder paste on the surface of the cover body.

[0005] It is understandable that the smaller the wetting angle of the solder paste on the material surface, the better the solderability of the material. The cover body is the main structure of the shielding cover. The cover body is made of a material with a lower density, which is conducive to the lightweight of the shielding cover. When the shielding cover is used in an electronic device, the flange of the shielding cover is fixedly connected to the circuit board of the electronic device by welding. The flange of the shielding cover connected to the circuit board is made of a material with good solderability. When the flange of the shielding cover is fixed to the circuit board by welding, it helps to improve the connection strength between the shielding cover and the circuit board.

[0006] In one embodiment, the density of the cover is less than or equal to 3.5 g / cm 3 And / or, the wetting angle of the solder paste on the surface of the flange is less than or equal to 40°. In this way, the flange has better solderability, the shielding cover is more efficient in the process of soldering to the circuit board, and the connection strength between the shielding cover and the circuit board is better.

[0007] In one embodiment, the shielding cover further comprises a connecting layer, which is fixedly connected between the cover body and the flange. The connecting layer comprises the material of the cover body and the material of the flange, and the content of the main group element of the material of the cover body gradually decreases from the cover body toward the flange, while the content of the main group element of the material of the flange gradually increases.

[0008] It can be understood that the connection layer includes the material of the cover body and the material of the flange, the connection strength between the cover body and the connection layer is better, and the connection strength between the flange and the connection layer is better.

[0009] In one embodiment, the thickness of the connection layer is greater than 0.1 μm. And / or, the thickness of the connection layer is in the range of 2 μm to 30 μm. In this case, the interface bonding strength between the flange and the cover body is better, and the overall strength of the shielding cover is better.

[0010] In one embodiment, the thermal conductivity of the cover body is greater than the thermal conductivity of the flange. The shielding cover is made of a material with good heat dissipation performance in the part that does not need to be welded, which can improve the heat dissipation efficiency of the electronic components.

[0011] In one embodiment, the material of the flange is nickel silver, and the material of the cover is aluminum alloy, particle reinforced aluminum-based composite material, magnesium alloy or particle reinforced magnesium-based composite material.

[0012] In one embodiment, part or all of the flange is arranged at an angle to the side wall of the cover body, and the flange and the cover body enclose an accommodating space.

[0013] In a second aspect, an embodiment of the present application provides a circuit board bracket. The circuit board bracket is used for electronic equipment. The circuit board bracket includes a main bracket and a fixing frame fixedly connected to the main bracket, the main bracket and the fixing frame are integrally formed structural parts, the main bracket and the fixing frame are both made of metal material, the hardness of the material of the fixing frame is greater than the hardness of the material of the main bracket, and the density of the fixing frame is greater than the density of the main bracket.

[0014] It is understandable that when the circuit board bracket is used in an electronic device, the circuit board bracket is fixedly connected to the circuit board of the electronic device. The fixing frame can be used to fix the connected circuit board or fix the board-to-board electrical connector connected on the circuit board. The fixing frame has a large hardness, so when the fixing frame and the circuit board are fixedly connected, the strength is better and it is not easy to be damaged, or when the fixing frame is against the BTB electrical connector, it is not easy to deform and has better reliability. At the same time, the main bracket is made of a material with a lower density, which can reduce the mass of the circuit board bracket and is conducive to the lightweight of the circuit board bracket.

[0015] In one embodiment, the density of the main support is less than 3.5 g / cm 3 The hardness of the material of the fixing frame is in the range of 100 HV to 400 HV. Thus, the main support is lighter in weight and the fixing frame has better hardness.

[0016] In one embodiment, the circuit board bracket further includes a connecting layer, and the connecting layer is fixedly connected between the fixing frame and the main bracket.

[0017] The connection layer includes the material of the main support and the material of the fixing frame. From the main support toward the fixing frame, the content of the main group elements of the material of the main support gradually decreases, and the content of the main group elements of the material of the fixing frame gradually increases.

[0018] It can be understood that the connection layer includes the material of the main support and the material of the fixing frame, the connection strength between the fixing frame and the connection layer is better, and the connection strength between the main support and the connection layer is better.

[0019] In one embodiment, the thickness of the connecting layer is greater than 0.1 μm. And / or, the thickness of the connecting layer is in the range of 2 μm to 30 μm. At this time, the interface bonding strength between the fixing frame and the main bracket is better, and the overall strength of the circuit board bracket is better. In one embodiment, the thermal conductivity of the main bracket is greater than the thermal conductivity of the fixing frame. In this way, when the circuit board bracket is fixedly connected to the circuit board of the electronic device, the main bracket of the circuit board bracket can assist in dissipating heat from the electronic components on the circuit board.

[0020] In one embodiment, the fixing frame is made of stainless steel, titanium alloy or steel-aluminum-steel laminated composite material. And / or the main support is made of aluminum alloy, particle-reinforced aluminum-based composite material, magnesium alloy or particle-reinforced magnesium-based composite material.

[0021] In one embodiment, the main support is provided with at least one matching structure, which is a protrusion, a groove or an avoidance hole. And / or, the fixing frame is provided with at least one fastening hole.

[0022] It is understandable that the matching structure can be used to avoid electronic components on the circuit board, the shielding cover, or other electronic devices provided in the internal space of the electronic device. When the circuit board bracket is fixedly connected to the circuit board of the electronic device, the matching structure can be a avoidance hole, and the electronic component can be partially located in the avoidance hole, and the shielding cover is partially located in the avoidance hole. In the thickness direction of the circuit board, the electronic components and the shielding cover overlap with the circuit board bracket, which is conducive to reducing the height of the electronic device in the thickness direction of the circuit board.

[0023] In a third aspect, an embodiment of the present application provides an electronic device, wherein the electronic device comprises a circuit board and a shielding cover, wherein the shielding cover is mounted on the circuit board.

[0024] or

[0025] It includes a housing and a circuit board bracket, and the circuit board bracket is mounted on the circuit board.

[0026] It comprises a shell, a shielding cover and a circuit board bracket, wherein the shielding cover and the circuit board bracket are both installed on the circuit board.

[0027] It can be understood that when the shielding cover and / or the circuit board bracket are used in electronic equipment, it is conducive to the lightweight of the electronic equipment, and the connection strength with the circuit board is better and the connection reliability is better.

[0028] In a fourth aspect, an embodiment of the present application provides a method for preparing a structural component. The preparation method comprises:

[0029] A sintered part is prepared, the sintered part comprises a frame and powder connecting the frame, the frame is made of a first metal material, the powder is made of a second metal material, and the density of the first metal material is greater than that of the second metal material.

[0030] The part to be sintered is sintered to form a green body, wherein the green body comprises a first part and a second part, the first part is formed by a frame, and the second part is formed by powder. And,

[0031] The blank is processed to form a structural member, which includes a first member and a second member fixedly connected to the first member, wherein the first member is formed by the first part, and the second member is formed by the second part.

[0032] Wherein, the structural member is a shielding cover, the first member is a flange, and the second member is a cover body. Alternatively, the structural member is a circuit board bracket, the first member is a fixing bracket, and the second member is a main bracket.

[0033] It can be understood that the above-mentioned preparation method can prepare an integrated structural part formed of two materials with different densities through a sintering process. Compared with the structural parts of two materials fixedly connected by traditional material interface bonding processes such as riveting, welding and bonding, the present application uses a sintering process to make the interface connection strength between the two materials of the structural part better, the overall strength of the structural part is better, and the interface connection is not easy to crack or deform or detach.

[0034] In one embodiment, in the step of "sintering the part to be sintered", the powder and the frame diffuse with each other to form a diffusion layer, the diffusion layer is connected between the first part and the second part, and the first part, the second part and the diffusion layer constitute the blank. The structural part also includes a connecting layer, and the connecting layer includes a first metal material and a second metal material.

[0035] In one embodiment, the part to be sintered is sintered using a hot isostatic pressing process.

[0036] The pressure P1 of the hot isostatic pressing sintering process satisfies: P1 ≥ 100Mpa.

[0037] The temperature T1 of the hot isostatic pressing sintering process satisfies: 500°C ≤ T1 ≤ 660°C.

[0038] The time t1 of the hot isostatic pressing sintering process satisfies: 2h≤t1≤5h.

[0039] It is understandable that the thickness of the diffusion layer changes according to the sintering process and time. The rule is: the longer the sintering time, the thicker the diffusion layer. The higher the sintering temperature, the thicker the diffusion layer. The greater the sintering pressure, the thicker the diffusion layer. At this point, while meeting the interface bonding strength, the sintering process can be accelerated and the energy consumption of the sintering process can be saved.

[0040] In one embodiment, after the step of "sintering the to-be-sintered part to form a green body" and before the step of "processing the green body to form a structural part", the preparation method further comprises:

[0041] The blank is solution treated.

[0042] Cool the dough to room temperature.

[0043] The blank is subjected to aging treatment.

[0044] It can be understood that by performing a solution treatment on the blank, the yield strength and hardness of the second part formed by the powder material can be enhanced, and by performing an aging treatment on the blank, the hardness of the second part formed by the powder material can be enhanced.

[0045] In one embodiment, the powder material is aluminum alloy or particle-reinforced aluminum-based composite material, the solution temperature T2 of the solution treatment satisfies: 500°C≤T2≤550°C, and the solution time t2 satisfies: 15min≤t2≤60min. And / or,

[0046] The temperature T3 of the aging treatment satisfies: 170°C ≤ T3 ≤ 200°C, and the aging time t3 satisfies: 4h ≤ t3 ≤ 24h.

[0047] In one embodiment, the powder material is a magnesium alloy or a particle-reinforced magnesium-based composite material, and the solution temperature T2 of the solution treatment satisfies: 380°C≤T2≤420°C, and the solution time t2 satisfies: 0.5h≤t2≤12h. And / or

[0048] The temperature T3 of the aging treatment satisfies: 180°C ≤ T3 ≤ 220°C, and the aging time t3 satisfies: 1h ≤ t3 ≤ 8h.

[0049] It is understandable that, depending on the material type of the powder, different solution treatment process parameters and aging treatment process parameters can be selected to enhance the yield strength and hardness of the second part formed by the powder, while achieving higher processing efficiency.

[0050] In one embodiment, in the step of "preparing the part to be sintered", the preparation method includes: using a cold isostatic pressing process to press the powder into a green compact, so that the powder forms a block. In this way, the powder can be prevented from scattering and is convenient for taking and placing.

[0051] In one embodiment, the pressure P4 of the cold isostatic pressing process satisfies: P4 ≥ 100 MPa, and the time t4 of the cold isostatic pressing process satisfies: 1 h ≤ t4 ≤ 3 h.

[0052] In one embodiment, the structural member is a shielding cover, and the wetting angle of the solder paste on the surface of the first metal material is less than or equal to 40°. And / or,

[0053] The structural member is a circuit board bracket, and the hardness of the first metal material is in the range of 100 HV to 400 HV. And / or,

[0054] The density of the second metal material is less than 3.5 g / cm 3 .

[0055] It is understandable that the structural member may be a shielding cover or a circuit board bracket in the electronic device, or other built-in metal structural members of the electronic device, such as a reinforcement plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to illustrate the technical solution of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be described below.

[0057] Figure 1 It is a structural schematic diagram of an implementation mode of an electronic device provided in an embodiment of the present application;

[0058] Figure 2 yes Figure 1 An exploded schematic diagram of an embodiment of an electronic device shown in ;

[0059] Figure 3 yes Figure 1 A partial cross-sectional view of an embodiment of the electronic device shown in FIG. 1 at section line AA;

[0060] Figure 4 yes Figure 3 An enlarged schematic diagram of the electronic device shown in FIG. 1 at B;

[0061] Figure 5 yes Figure 4 Schematic diagram of the variation trend of component content in the connecting layer shown in ;

[0062] Figure 6 yes Figure 3 A step diagram of a method for preparing an embodiment of a shielding cover shown in ;

[0063] Figures 7 to 9 yes Figure 6 A schematic diagram of a part of the structure of one embodiment of the shielding cover in the preparation steps shown;

[0064] Fig.10 yes Figure 3 A schematic structural diagram of an embodiment of a circuit board bracket shown in ;

[0065] Fig.11 yes Fig.10 A step diagram of a method for preparing an embodiment of a circuit board bracket shown in FIG.

[0066] Figure 12 to Figure 14 yes Fig.11 A schematic diagram of a part of the structure of one embodiment of a circuit board bracket in the preparation steps shown;

[0067] Fig.15 yes Figure 1 An exploded schematic diagram of yet another embodiment of the electronic device shown in ;

[0068] Fig.16 yes Figure 1 A partial cross-sectional view of yet another embodiment of the electronic device shown in FIG. 1 at section line AA. DETAILED DESCRIPTION

[0069] The embodiments of the present application are described below in conjunction with the drawings in the embodiments of the present application.

[0070] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "installation" and "connection" should be understood in a broad sense. For example, "connection" can be a detachable connection or a non-detachable connection; it can be a direct connection or an indirect connection through an intermediate medium. Among them, "fixed connection" means that the two are connected to each other and the relative position relationship after the connection remains unchanged. It should be understood that when component A is fixedly connected to component C through component B, changes in the relative position relationship caused by the deformation of component A, component B and component C itself are allowed. "Rotational connection" means that they are connected to each other and can rotate relative to each other after the connection. "Sliding connection" means that they are connected to each other and can slide relative to each other after the connection. Among them, the two components are obtained by an integrated structure through an integrated molding process, which means that in the process of forming one of the two components, the component is connected to the other component, and there is no need to connect the two components together through reprocessing (such as bonding, welding, snap connection, screw connection).

[0071] The directional terms mentioned in the embodiments of the present application, such as "upper", "lower", "side", "top", "bottom", etc., are only references to the directions of the drawings. Therefore, the directional terms used are for better and clearer explanation and understanding of the embodiments of the present application, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0072] The term "plurality" means at least two. The term "above" includes the number itself. The term "and / or" is a description of an association relationship between associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist at the same time, and B exists alone. The terms "first", "second", etc. are used only for descriptive purposes and cannot be understood as suggesting or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0073] Figure 1 It is a structural diagram of an implementation of an electronic device 100 provided in an embodiment of the present application.

[0074] The electronic device 100 may include, but is not limited to, a mobile phone, a tablet computer, a laptop computer, an ultra-mobile personal computer (UMPC), a handheld computer, a walkie-talkie, a netbook, a POS machine, a personal digital assistant (PDA), a wearable device, or a virtual reality device. Figure 1 The electronic device 100 shown in FIG. 1 is introduced by taking a mobile phone as an example.

[0075] Figure 2 yes Figure 1 An exploded schematic diagram of an embodiment of an electronic device 100 is shown in FIG. Figure 3 yes Figure 1 FIG. 1 is a partial cross-sectional view of an embodiment of the electronic device 100 at the section line AA.

[0076] like Figure 2 and Figure 3 As shown, the electronic device 100 may include a screen 10, a housing 20, a circuit board 30, an electronic component 40 mounted on the circuit board 30, a shielding cover 50, and a circuit board bracket 60. The screen 10 is mounted on the housing 20. The screen 10 and the housing 20 enclose an internal space 70 of the electronic device 100. The circuit board 30, the electronic component 40, the shielding cover 50, and the circuit board bracket 60 are all mounted in the internal space 70 of the electronic device 100.

[0077] The screen 10 can be used to display images, videos, etc. In some embodiments, the screen 10 can also have a touch sensing function, and the touch sensing function of the screen 10 is used to sense the user's touch action to achieve human-computer interaction. Exemplarily, the screen 10 can be a liquid crystal display (LCD), an organic light-emitting diode (OLED) display, an active-matrix organic light-emitting diode or an active-matrix organic light-emitting diode (AMOLED) display, a flexible light-emitting diode (FLED) display, a Mini-LED display, a Micro-LED display, a Micro-OLED display, a quantum dot light emitting diode (QLED) display, etc.

[0078] The housing 20 may be made of metal, glass, plastic, or ceramic.

[0079] For example, the electronic component 40 may be an active device such as a chip, or a passive device such as a capacitor, an inductor, a resistor, etc. It is understandable that those skilled in the art can select the type of the electronic component 40 and the connection method thereof on the circuit board 30 so as to form a circuit board assembly with specific functions with the circuit board 30.

[0080] The shielding cover 50 is fixedly connected to the circuit board 30. The shielding cover 50 can be used to shield the electronic components 40 on the circuit board 30 to prevent electromagnetic interference.

[0081] In some embodiments, the electronic device 100 further includes an electronic device. The electronic device is installed in the internal space 70 of the electronic device 100. The electronic device may include a battery, a processor, a communication module, a camera, an audio module, a speaker, a microphone, and a subscriber identification module (SIM) card.

[0082] The circuit board bracket 60 is fixedly connected to the circuit board 30. The circuit board bracket 60 is used to fix the structure on the circuit board 30 to prevent the structure on the circuit board 30 from interfering with other electronic devices in the internal space 70 of the electronic device 100, so as to facilitate the assembly of the electronic device 100. Exemplarily, the circuit board bracket 60 can be fixed to the side of the circuit board 30 facing the screen 10.

[0083] In some embodiments, the circuit board bracket 60 and the shielding cover 50 may be fixed to the same side of the circuit board 30 .

[0084] Figure 4 yes Figure 3 FIG. 1 is an enlarged schematic diagram of the electronic device 100 at point B shown in FIG.

[0085] like Figure 3 and Figure 4 As shown, the shielding cover 50 is connected to the circuit board 30. The shielding cover 50 has a accommodating space 31. The electronic component 40 that requires electromagnetic shielding can be located in the accommodating space 31. Exemplarily, the shielding cover 50 includes a cover body 51 and a flange 52. The cover body 51 and the flange 52 surround the accommodating space 31. Among them, part or all of the flange 52 can be set at an angle to the side wall of the cover body 51. One end of the flange 52 is fixedly connected to the circuit board 30, and the other end of the flange 52 is fixedly connected to the periphery of the cover body 51. The cover body 51 and the flange 52 are an integrally formed structural member. Exemplarily, the flange 52 can be fixedly connected to the circuit board 30 by welding.

[0086] The cover body 51 and the flange 52 are both made of metal material, and the material density of the flange 52 is greater than the material density of the cover body 51, and the wetting angle of the solder paste on the surface of the flange 52 is smaller than the wetting angle of the solder paste on the surface of the cover body 51. It can be understood that the smaller the wetting angle of the solder paste on the surface of the material, the better the solderability of the material. The cover body 51 is the main structure of the shielding cover 50, and the cover body 51 is made of a material with a lower density, which is conducive to the lightweight of the shielding cover 50. At the same time, the flange 52 of the shielding cover 50 connected to the circuit board 30 is made of a material with good solderability. When the flange 52 of the shielding cover 50 is fixed to the circuit board 30 by welding, it helps to improve the connection strength between the shielding cover 50 and the circuit board 30. Exemplarily, the wetting angle of the solder paste on the surface of the flange 52 can be measured by a sessile drop method.

[0087] In some embodiments, the material density of the cover 51 is less than or equal to 3.5 grams per cubic centimeter (g / cm 3 For example, the material density of the cover body 51 can be 1.0 g / cm 3 , 2.0g / cm 3 or 3.5g / cm 3 .

[0088] In some embodiments, the material density of the flange 52 is 4.0 g / cm 3 Up to 8.9g / cm 3 For example, the material density of the flange 52 may be 4.0 g / cm 3 、6.0g / cm 3 or 8.9g / cm 3.

[0089] In some embodiments, the wetting angle of the solder paste on the surface of the flange 52 is less than or equal to 40°. In this way, the solderability of the flange 52 is better, the shielding cover 50 is more efficient in the process of being soldered to the circuit board 30, and the connection strength between the shielding cover 50 and the circuit board 30 is better. For example, the wetting angle of the solder paste on the surface of the flange 52 can be 10°, 20°, or 40°, etc.

[0090] In some embodiments, the material of the flange 52 may be nickel silver. For example, the material of the flange 52 may be C7521 nickel silver. The material of the cover body 51 may be aluminum alloy, particle-reinforced aluminum-based composite material, magnesium alloy or particle-reinforced magnesium-based composite material. For example, the material of the cover body 51 may be 5059 aluminum alloy.

[0091] In some embodiments, the thermal conductivity of the cover body 51 is greater than the thermal conductivity of the flange 52. In this way, the shielding cover 50 is made of a material with good heat dissipation in the part that does not need to be welded, which can improve the heat dissipation efficiency of the electronic component 40.

[0092] In some embodiments, the cover body 51 and the flange 52 can be formed into an integral structural member by a sintering process. The sintering process (also known as powder metallurgy) is a process in which a powder or a powder compact is heated to a temperature lower than the melting point of the basic components therein, and then cooled to room temperature in a certain method and speed. The result of sintering is that the powder particles or the powder particles and the parts are bonded to each other, and finally the powder condenses into a block to form a structural member. The shielding cover 50 also includes a connecting layer 53, which is fixedly connected between the cover body 51 and the flange 52. The connecting layer 53 is formed by a sintering process. During the sintering process, due to thermal diffusion, the atoms of the material of the cover body 51 and the material of the flange 52 move in the direction of low concentration to form a connecting layer 53.

[0093] It is understandable that, compared to the flange 52 being connected to the cover body 51 through traditional material interface bonding processes such as forging, riveting, welding and bonding, the present application forms an integral structural member of the cover body 51 and the flange 52 through a sintering process. In this way, the interface connection strength between the cover body 51 and the flange 52 is better, the overall strength of the shielding cover 50 is better, and the interface connection is not easy to crack or deform or detach. In addition, when the shielding cover 50 is formed using a sintering process, the structural member to be sintered can be shaped by a mold before sintering, the shape and position of the flange 52 can be flexibly set, and the structure of the shielding cover 50 can be diversified.

[0094] Figure 5 yes Figure 4The schematic diagram of the variation trend of the component content in the connecting layer 53 is shown in FIG. The positive direction of the X axis in the coordinate axis represents the direction of the cover body 51 toward the flange 52, the Y axis represents the component content, and W is the thickness of the connecting layer 53.

[0095] like Figure 4 and Figure 5 As shown, the connection layer 53 may include the material of the cover body 51 and the material of the flange 52. Along the direction from the cover body 51 to the flange 52, the content of the main group elements of the material of the cover body 51 gradually decreases, and the content of the main group elements of the material of the flange 52 gradually increases. The material of the cover body 51 and the material of the flange 52 are mostly alloy materials, and the main group elements of the alloy material refer to the elements with the highest content in the alloy. In alloys, some other elements are usually added to change their performance and characteristics, but the content of the main group elements is the highest and plays a dominant role in the properties of the alloy. The selection and content of the main group elements determine the chemical composition and basic properties of the alloy. For example, for stainless steel, iron is the main group element, and other added elements such as chromium and nickel play a role in improving corrosion resistance. For titanium alloys, titanium is the main group element; for aluminum alloys and particle-reinforced aluminum-based composites, aluminum is the main group element; for magnesium alloys and particle-reinforced magnesium-based composites, magnesium is the main group element.

[0096] The thickness of the connection layer 53 may be greater than 0.1 μm in the direction from the cover body 51 to the flange 52. Exemplarily, the width of the connection layer 53 is in the range of 2 μm to 30 μm, for example, the thickness of the connection layer 53 may be 2 μm, 10 μm, 20 μm or 30 μm. At this time, the interface bonding strength between the flange 52 and the cover body 51 is better, and the overall strength of the shielding cover 50 is better.

[0097] In some embodiments, the interface of the connecting layer 53 facing the flange 52 and the interface of the connecting layer 53 facing the cover body 51 are clearly visible under a metallographic microscope. The resolution of the metallographic microscope is at the micron level. Since the connecting layer 53 is formed by atomic diffusion during the sintering process, during the sintering process, the force at each position of the connecting layer 53 is relatively uniform, and the thickness of the connecting layer 53 is equal or approximately equal in the extension direction of the connecting layer 53, that is, the interface of the connecting layer 53 facing the flange 52 and the interface of the connecting layer 53 facing the cover body 51 are parallel or approximately parallel (slight convexity and concavity of the interface are allowed).

[0098] Partial implementations of the shielding cover 50 are described in detail above in conjunction with the relevant drawings. A method for preparing the shielding cover 50 in one implementation will be described in detail below in conjunction with the relevant drawings. Figure 6 yes Figure 3 FIG. 1 is a diagram showing steps of a method for preparing a shielding cover 50 according to an embodiment of the present invention. Figures 7 to 9 yes Figure 6 A partial structural schematic diagram of a preparation step of a shielding cover 50 in one embodiment is shown.

[0099] like Figures 6 to 9 As shown, the steps of preparing the shielding cover 50 may include the following steps:

[0100] Step S101: Figure 7 As shown, a sintered part 81 is prepared, and the sintered part 81 includes a frame 811 and a powder 812 connected to the frame 811. The frame 811 is made of a first metal material, and the powder 812 is made of a second metal material. The density of the first metal material is greater than that of the second metal material, and the wetting angle of the solder paste on the surface of the first metal material is less than the wetting angle of the solder paste on the surface of the second metal.

[0101] Exemplarily, the frame 811 may be provided with an inner cavity 813, and the powder 812 is filled in the inner cavity 813 to form the sintered part 81. The inner cavity 813 included in the frame 811 may be one or more ( Figure 7 In some embodiments, the frame 811 can be formed by a stamping process.

[0102] Exemplarily, the wetting angle of the solder paste on the surface of the first metal material is less than or equal to 40°. The density of the second metal material is less than 3.5 g / cm 3 .

[0103] For example, the first metal material may be nickel silver, and the second metal material may be aluminum alloy, particle reinforced aluminum-based composite material, magnesium alloy or particle reinforced magnesium-based composite material.

[0104] Step S102: Figure 7 and Figure 8 As shown, the part to be sintered 81 is sintered to form a green body 82 , wherein the green body 82 includes a first part 821 and a second part 822 , the first part 821 is formed by a frame 811 , and the second part 822 is formed by a powder material 812 .

[0105] Exemplarily, a hot isostatic pressing sintering process can be used to sinter the sintered part 81. During the sintering process, the powder 812 and the frame 811 diffuse with each other to form a diffusion layer 823, which is connected between the first part 821 and the second part 822. The first part 821, the second part 822 and the diffusion layer 823 constitute the blank 82.

[0106] In some embodiments, the pressure P1 (unit: megapascal, MPa) of the hot isostatic pressing sintering process satisfies: P1 ≥ 100 MPa, the temperature T1 (unit: degrees Celsius, ℃) of the hot isostatic pressing sintering process satisfies: 500℃≤T1≤660℃, and the time t1 (unit: hour, h) of the hot isostatic pressing sintering process satisfies: 2h≤t1≤5h.

[0107] It is understandable that the thickness of the diffusion layer 823 varies according to the sintering process and time. The rule is: the longer the sintering time, the thicker the diffusion layer 823. The higher the sintering temperature, the thicker the diffusion layer 823. The greater the sintering pressure, the thicker the diffusion layer 823. Exemplarily, the thickness of the diffusion layer 823 is in the range of 2 μm to 30 μm. At this time, while meeting the interface bonding strength, the sintering process can be accelerated and the energy consumption of the sintering process can be saved.

[0108] Step S103: Processing the blank 82 to form Figure 3 The shielding cover 50 shown in the figure includes a cover body 51 and a flange 52 fixedly connected to the cover body 51 . The flange 52 is formed by a first part 821 , and the cover body 51 is formed by a second part 822 .

[0109] The process of processing the blank 82 includes but is not limited to one or more of CNC (Computer numerical control, CNC) machine tool processing, stamping, surface treatment, mechanical polishing, laser engraving and the like. For example, Figure 8 The blank 82 shown in the figure can be cut and ground according to the dotted lines to obtain Fig. 9 The four parts to be stamped 83 are shown in the figure, and then the parts to be stamped 83 are subjected to a stamping process to obtain a shielding cover 50 with a certain shape.

[0110] It can be understood that the shielding cover 50 prepared by the above steps. The shielding cover 50 includes a cover body 51 and a flange 52. The flange 52 is fixedly connected to the periphery of the cover body 51. The cover body 51 and the flange 52 are formed into an integrally formed structural member by a sintering process, and the cover body 51 and the flange 52 are both made of metal material. The material density of the flange 52 is greater than the material density of the cover body 51. The wetting angle of the solder paste on the surface of the flange 52 is less than the wetting angle of the solder paste on the surface of the cover body 51. In this way, the flange 52 connected to the circuit board 30 in the shielding cover 50 is made of a material with good solderability, and the cover body 51 is made of a material with a lower density. When the flange 52 of the shielding cover 50 is fixed to the circuit board 30 by welding, the connection strength between the shielding cover 50 and the circuit board 30 is better, and at the same time, the shielding cover 50 is lighter, which is conducive to the lightweight of the electronic device 100. When the hot isostatic pressing sintering process is used to sinter the sintered component 81 , the shielding cover 50 further includes a connection layer 53 . The connection layer 53 is formed by the diffusion layer 823 . The connection layer 53 includes a first metal material and a second metal material.

[0111] In some embodiments, after the step of “sintering the to-be-sintered part 81 to form a blank 82” and before the step of “processing the blank 82 to form a shielding cover 50”, the preparation method further comprises:

[0112] Performing a solid solution treatment on the blank 82;

[0113] Cooling the blank 82 to room temperature;

[0114] The blank 82 is subjected to aging treatment.

[0115] Exemplarily, the powder 812 is made of aluminum alloy or particle-reinforced aluminum-based composite material, and the solution temperature T2 of the solution treatment satisfies: 500°C ≤ T2 ≤ 550°C, and the solution time t2 satisfies: 15min ≤ t2 ≤ 60min. The powder 812 is made of magnesium alloy or particle-reinforced magnesium-based composite material, and the solution temperature T2 of the solution treatment satisfies: 380°C ≤ T2 ≤ 420°C, and the solution time t2 satisfies: 0.5h ≤ t2 ≤ 12h. It can be understood that by performing solution treatment on the blank 82, the yield strength and hardness of the second part 822 formed by the powder 812 can be enhanced, thereby improving the yield strength and hardness of the cover carrier 51.

[0116] Exemplarily, the powder 812 is made of aluminum alloy or particle-reinforced aluminum-based composite material, and the aging treatment temperature T3 satisfies: 170°C ≤ T3 ≤ 200°C, and the aging time t3 satisfies: 4h ≤ t3 ≤ 24h. The powder 812 is made of magnesium alloy or particle-reinforced magnesium-based composite material, and the aging treatment temperature T3 satisfies: 180°C ≤ T3 ≤ 220°C, and the aging time t3 satisfies: 1h ≤ t3 ≤ 8h. It can be understood that by aging the blank 82, the hardness of the second part 822 formed by the powder 812 can be enhanced, thereby improving the hardness of the cover body 51.

[0117] Exemplarily, cooling the blank 82 to room temperature may be achieved by a water quenching process.

[0118] In some embodiments, in the step of "preparing the sintered part 81", the preparation method includes: using a cold isostatic pressing process to perform powder compaction so that the powder 812 forms a block. In this way, the powder 812 can be prevented from scattering and is convenient for taking and placing. Exemplarily, the pressure P4 of the cold isostatic pressing process satisfies: P4 ≥ 100 MPa, and the time t4 of the cold isostatic pressing process satisfies: 1h ≤ t4 ≤ 3h.

[0119] Fig.10 yes Figure 3 A schematic structural diagram of an embodiment of a circuit board bracket 60 is shown in FIG.

[0120] like Figure 3 and Fig.10As shown, the circuit board bracket 60 includes a main bracket 61 and a fixing bracket 62 fixedly connected to the main bracket 61. The fixing bracket 62 can be used to fix the circuit board 30 or fix the board to board connector (BTB) connected to the circuit board 30. The BTB electrical connector is used to access the electrical signal of the electronic device. For example, the camera outputs the electrical signal through the flexible circuit board 90 and is connected to the circuit board 30 through the BTB electrical connector.

[0121] In some embodiments, the fixing frame 62 is provided with at least one fastening hole 621. A screw can pass through the fastening hole 621, so that the fixing frame 62 is fixedly connected to the circuit board 30, and the circuit board bracket 60 is fixedly connected to the circuit board 30. When the fixing frame 62 is used to fix the BTB electrical connector, the fixing frame 62 can abut the BTB electrical connector, and the BTB electrical connector is at least partially clamped between the circuit board 30 and the fixing frame 62, so as to fix the BTB electrical connector. In other embodiments, the fixing frame 62 can also be fixedly connected to the circuit board 30 by other connection methods such as snap-fitting.

[0122] In some embodiments, the main bracket 61 is provided with at least one matching structure 611. The matching structure 611 may be a protrusion or a groove or an avoidance hole. The matching structure 611 may be used to avoid the electronic components 40 on the circuit board 30, the shielding cover 50 or other electronic devices provided in the internal space 70 of the electronic device 100, such as the electronic components 40, the shielding cover 50, the camera and other structures. Exemplarily, the matching structure 611 is an avoidance hole, the electronic component 40 is partially located in the avoidance hole, and the shielding cover 50 is partially located in the avoidance hole. In this way, in the thickness direction of the circuit board 30, the electronic components 40 and the shielding cover 50 overlap with the circuit board bracket 60, which is conducive to reducing the height of the electronic device 100 in the thickness direction of the circuit board 30.

[0123] The main bracket 61 and the fixing bracket 62 are integrally formed structural members. Both the main bracket 61 and the fixing bracket 62 are made of metal material. The hardness of the material of the fixing bracket 62 is greater than the hardness of the material of the main bracket 61. The density of the fixing bracket 62 is greater than the density of the main bracket 61. It can be understood that the hardness of the fixing bracket 62 is relatively large, so that when the fixing bracket 62 and the circuit board 30 are fixedly connected, the strength is better and it is not easy to be damaged, or when the fixing bracket 62 is against the BTB electrical connector, it is not easy to deform and the reliability is better. At the same time, the main bracket 61 is made of a material with a lower density, which can reduce the mass of the circuit board bracket 60, which is conducive to the lightweight electronic device 100.

[0124] In some embodiments, the density of the fixture 62 may be 4.0 g / cm 3 Up to 8.9g / cm 3For example, the density of the fixing frame 62 may be 4.0 g / cm 3 、6.0g / cm 3 or 8.9g / cm 3 The density of the main support 61 can be less than 3.5 g / cm 3 For example, the density of the main support 61 can be 1.0 g / cm 3 , 2.0g / cm 3 or 3.5g / cm 3 .

[0125] In some embodiments, the hardness of the material of the main support 61 may be in the range of 80 HV to 140 HV. For example, the hardness of the material of the main support 61 may be 80 HV, 100 HV, 120 HV, or 140 HV. The hardness of the material of the fixing frame 62 may be in the range of 100 HV to 400 HV. For example, the hardness of the material of the fixing frame 62 may be 100 HV, 200 HV, 300 HV, or 400 HV.

[0126] In some embodiments, the elastic modulus of the material of the fixing frame 62 may be greater than the elastic modulus of the material of the main support 61 .

[0127] In some embodiments, the yield strength of the material of the fixing bracket 62 may be greater than the yield strength of the material of the main bracket 61 .

[0128] In some embodiments, the material of the fixing frame 62 can be stainless steel, titanium alloy or steel-aluminum-steel laminated composite material. The material of the main support 61 can be aluminum alloy, particle-reinforced aluminum-based composite material, magnesium alloy or particle-reinforced magnesium-based composite material. Exemplarily, the material of the fixing frame 62 can be SUS316L stainless steel with a density of 7.93 g / cm 3 The main support 61 can be made of 6013 aluminum alloy with a density of 2.7 g / cm 3 , the elastic modulus is 69GPa.

[0129] In some embodiments, the thermal conductivity of the main bracket 61 is greater than the thermal conductivity of the fixing bracket 62. In this way, the main bracket 61 of the circuit board bracket 60 can assist the electronic components 40 on the circuit board 30 in dissipating heat.

[0130] In some embodiments, the main support 61 and the fixing frame 62 can be formed into an integral structure by a sintering process.

[0131] In some embodiments, the circuit board bracket 60 further includes a connection layer 63, and the connection layer 63 is fixedly connected between the fixing frame 62 and the main bracket 61. The connection layer 63 is formed by a sintering process. During the sintering process, the material of the main bracket 61 and the material of the fixing frame 62 moves toward a direction with a low concentration due to thermal diffusion, thereby forming the connection layer 63. The connection layer 63 may include the material of the main bracket 61 and the material of the fixing frame 62.

[0132] Exemplarily, along the direction from the main support 61 to the fixing frame 62, the content of the main group elements of the material of the main support 61 gradually decreases, and the content of the main group elements of the material of the fixing frame 62 gradually increases. The materials of the main support 61 and the fixing frame 62 are mostly alloy materials, and the main group elements of the alloy materials refer to the elements with the highest content in the alloy. In alloys, some other elements are usually added to change their performance and characteristics, but the content of the main group elements is the highest and plays a dominant role in the properties of the alloy. The selection and content of the main group elements determine the chemical composition and basic properties of the alloy. For example, for stainless steel, iron is the main group element, and other added elements such as chromium and nickel play a role in improving corrosion resistance. For titanium alloys, titanium is the main group element; for aluminum alloys and particle-reinforced aluminum-based composites, aluminum is the main group element; for magnesium alloys and particle-reinforced magnesium-based composites, magnesium is the main group element.

[0133] The thickness of the connection layer 63 may be greater than 0.1 μm in the direction from the main support 61 to the fixing frame 62. For example, the width of the connection layer 63 is in the range of 2 μm to 30 μm, for example, the thickness of the connection layer 63 may be 2 μm, 10 μm, 20 μm or 30 μm. At this time, the interface bonding strength between the fixing frame 62 and the main support 61 is better, and the overall strength of the circuit board support 60 is better.

[0134] In some embodiments, the interface of the connecting layer 63 facing the fixing frame 62 and the interface of the connecting layer 63 facing the main support 61 are clearly visible under a metallographic microscope. The resolution of the metallographic microscope is at the micron level. Since the connecting layer 63 is formed by atomic diffusion during the sintering process, during the sintering process, the force at each position of the connecting layer 63 is relatively uniform, and the thickness of the connecting layer 63 is equal or approximately equal in the extension direction of the connecting layer 63, that is, the interface of the connecting layer 63 facing the fixing frame 62 and the interface of the connecting layer 63 facing the main support 61 are parallel or approximately parallel (slight convexity and concavity of the interface are allowed).

[0135] It is understandable that the number of the fixing frame 62 included in the circuit board bracket 60 can be one or more. The fixing frame 62 can be fixed to one side of the main bracket 61 (such as Figure 7The number of connecting layers 63 is the same as the number of fixing frames 62. For example, when the circuit board support 60 includes a plurality of fixing frames 62 arranged at intervals, the number of connecting layers 63 included in the circuit board support 60 is equal to the number of fixing frames 62, and the number of connecting layers 63 is one-to-one corresponding to the number of fixing frames 62. Each connecting layer 63 is connected between its corresponding fixing frame 62 and the main support 61.

[0136] Several embodiments of the circuit board bracket 60 are specifically introduced above in conjunction with the relevant drawings. A preparation method of the circuit board bracket 60 in one embodiment will be specifically introduced below in conjunction with the relevant drawings. Fig.11 yes Fig.10 FIG. 1 is a diagram showing steps of a method for preparing an embodiment of a circuit board bracket 60 shown in FIG. Figure 12 to Figure 14 yes Fig.11 The circuit board bracket 60 shown is a partial structural schematic diagram of the preparation steps of an embodiment.

[0137] like Figures 11 to 14 As shown, the steps of preparing the circuit board bracket 60 may include the following steps:

[0138] Step S201: Fig.12 As shown, a sintered part 91 is prepared, and the sintered part 91 includes a frame 911 and a powder 912 connected to the frame 911. The frame 911 is made of a first metal material, and the powder 912 is made of a second metal material. The density of the first metal material is greater than the density of the second metal material, and the hardness of the first metal material is greater than the hardness of the second metal material.

[0139] Exemplarily, the hardness of the first metal material is in the range of 100 HV to 400 HV. The density of the second metal material is less than 3.5 g / cm 3 .

[0140] For example, the first metal material may be stainless steel, titanium alloy or steel-aluminum-steel laminated composite material. The second metal material may be aluminum alloy, particle-reinforced aluminum-based composite material, magnesium alloy or particle-reinforced magnesium-based composite material.

[0141] Exemplarily, the first metal material may be formed into the frame 911 by roll forming.

[0142] Step S202: Fig.13 As shown, the sintered part 91 is sintered to form a blank 92, wherein the blank 92 includes a first portion 921 and a second portion 922, the first portion 921 is formed by a frame 911, and the second portion 922 is formed by a powder material 912;

[0143] Exemplarily, a hot isostatic pressing sintering process can be used to sinter the sintered part 91. In some embodiments, the pressure P1 (unit: megapascal, MPa) of the hot isostatic pressing sintering process satisfies: P1 ≥ 100 MPa, the temperature T1 (unit: degrees Celsius, ° C) of the hot isostatic pressing sintering process satisfies: 500 ° C ≤ T1 ≤ 660 ° C, and the time t1 (unit: hour, h) of the hot isostatic pressing sintering process satisfies: 2h ≤ t1 ≤ 5h. During the sintering process, the powder 912 and the frame 911 diffuse with each other to form a diffusion layer 923, and the diffusion layer 923 is connected between the first part 921 and the second part 922. The first part 921, the second part 922 and the diffusion layer 923 constitute the blank 92.

[0144] Step S203: Fig.14 As shown, the blank 92 is processed to form Fig.10 The circuit board bracket 60 shown includes a main bracket 61 and a fixing frame 62 fixedly connected to the main bracket 61 . The fixing frame 62 is formed by a first part 921 , and the main bracket 61 is formed by a second part 922 .

[0145] When the hot isostatic pressing process is used to sinter the sintered component 91, the circuit board bracket 60 further includes a connection layer 63, which is formed by a diffusion layer 923 and includes a first metal material and a second metal material.

[0146] The process of processing the blank 92 includes but is not limited to one or more of slicing, CNC (Computer numerical control, CNC) machine tool processing, stamping, surface treatment, mechanical polishing, laser engraving, etc. For example, the blank 92 obtained after sintering is first trimmed according to the required external dimensions to obtain a cross-section of a suitable shape and size, and then sliced ​​along the length direction to obtain a plate 93, and finally the plate 93 is ground and stamped to obtain the circuit board bracket 60.

[0147] It can be understood that the circuit board bracket 60 prepared by the above steps. The circuit board bracket 60 includes a main bracket 61 and a fixing frame 62 fixedly connected to the main bracket 61. The main bracket 61 and the fixing frame 62 are formed into an integrally formed structural member through a sintering process. The main bracket 61 and the fixing frame 62 are both made of metal materials. The hardness of the material of the fixing frame 62 is greater than the hardness of the material of the main bracket 61, and the density of the fixing frame 62 is greater than the density of the main bracket 61. In this way, the hardness of the fixing frame 62 is relatively large, so that when the fixing frame 62 and the circuit board 30 are fixedly connected, the strength is better and it is not easy to be damaged, or when the fixing frame 62 is against the BTB electrical connector, it is not easy to deform and the reliability is better. At the same time, the main bracket 61 is prepared using a material with a lower density, which can reduce the mass of the circuit board bracket 60, which is conducive to the lightweight of the electronic device 100.

[0148] It can be understood that the preparation method of the circuit board bracket 60 may also include treatment steps such as solution treatment, aging treatment, and cold isostatic pressing. The specific implementation method can refer to the solution treatment, aging treatment, and cold isostatic pressing implementation methods in the preparation method of the shielding cover 50 shown above, which will not be repeated here.

[0149] In an embodiment of the present application, a method for preparing a structural member is disclosed, and the method for preparing the structural member comprises:

[0150] Step 1: preparing a part to be sintered, the part to be sintered includes a frame and powder connecting the frame, the frame is made of a first metal material, the powder is made of a second metal material, and the density of the first metal material is greater than that of the second metal material;

[0151] Step 2: Sintering the part to be sintered to form a green body, wherein the green body comprises a first part and a second part, the first part is formed by a frame, and the second part is formed by powder;

[0152] Step three: Process the blank to form a structural member, wherein the structural member includes a first member and a second member fixedly connected to the first member, wherein the first member is formed by the first part, and the second member is formed by the second part.

[0153] An integrated structural part formed by two materials with different densities is prepared by the above-mentioned preparation method through a sintering process. Compared with structural parts in which two materials are fixedly connected by traditional material interface bonding processes such as riveting, welding and bonding, the present application uses a sintering process to make the interface connection strength between the two materials of the structural part better, the overall strength of the structural part is better, and the interface connection is not easy to crack or deform or detach. The above-mentioned preparation method can be used to prepare the shielding cover 50 and the circuit board bracket 60 introduced in the embodiments of this article, and can also be used to prepare other built-in metal structural parts of the electronic device 100, such as reinforcement plates.

[0154] In some embodiments, the same technical contents as those in the embodiments shown above are not repeated. Fig.15 yes Figure 1 FIG. 2 is an exploded schematic diagram of yet another embodiment of an electronic device 100 shown in FIG. Fig.16 yes Figure 1 FIG. 4 is a partial cross-sectional view of yet another embodiment of the electronic device 100 at the section line AA.

[0155] like Fig.15 and Fig.16As shown, the housing 20 may include a middle frame 21 and a back cover 22. The middle frame 21 is connected between the back cover 22 and the screen 10. The circuit board 30, the electronic component 40, the shielding cover 50 and the circuit board bracket 60 are all located between the middle frame 21 and the back cover 22. The electronic component 40 is mounted on a side surface of the circuit board 30 facing the back cover 22, and the circuit board bracket 60 and the shielding cover 50 are fixedly connected to the side of the circuit board 30 facing the back cover 22.

[0156] It is understandable that the positions of the shielding cover 50 and the circuit board bracket 60 can be flexibly adjusted according to the actual setting structure of the electronic device 100. The number of shielding covers 50 included in the electronic device 100 can be one or more. The number of circuit board brackets 60 included in the electronic device 100 can be one or more. The number of shielding covers 50 and the number of circuit board brackets 60 included in the electronic device 100 shown in the drawings of the present application are only examples of one embodiment. In addition, the electronic device 100 may also include only any one of the shielding cover 50 and the circuit board bracket 60. The electronic device 100 shown in the drawings of the present application is only an example of one embodiment.

[0157] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A shielding cover (50), applied to an electronic device (100), characterized in that: The shielding cover (50) comprises a cover body (51) and a flange (52), wherein the flange (52) is fixedly connected to the periphery of the cover body (51), the cover body (51) and the flange (52) are integrally formed structural parts, the cover body (51) and the flange (52) are both made of metal material, and the material density of the flange (52) is greater than the material density of the cover body (51), and the wetting angle of the solder paste on the surface of the flange (52) is smaller than the wetting angle of the solder paste on the surface of the cover body (51).

2. The shielding cover (50) according to claim 1, characterized in that: The density of the cover body (51) is less than or equal to 3.5 g / cm 3 and / or, The wetting angle of the solder paste on the surface of the flange (52) is less than or equal to 40°.

3. The shielding cover (50) according to claim 1 or 2, characterized in that: The shielding cover (50) further comprises a connecting layer (53), wherein the connecting layer (53) is fixedly connected between the cover body (51) and the flange (52); The connecting layer (53) comprises the material of the cover body (51) and the material of the flange (52); along the direction from the cover body (51) to the flange (52), the content of the main group elements of the material of the cover body (51) gradually decreases, while the content of the main group elements of the material of the flange (52) gradually increases.

4. The shielding cover (50) according to claim 3, characterized in that: The thickness of the connecting layer is greater than 0.1 μm; and / or The thickness of the connecting layer is in the range of 2 μm to 30 μm.

5. The shielding cover (50) according to any one of claims 1 to 4, characterized in that: The thermal conductivity of the cover body (51) is greater than the thermal conductivity of the flange (52).

6. The shielding cover (50) according to any one of claims 1 to 5, characterized in that: The material of the flange (52) is nickel silver; The cover body (51) is made of aluminum alloy, particle-reinforced aluminum-based composite material, magnesium alloy or particle-reinforced magnesium-based composite material.

7. The shielding cover (50) according to any one of claims 1 to 6, characterized in that: Part or all of the flange (52) is arranged at an angle with the side wall of the cover body (51), and the flange (52) and the cover body (51) enclose a containing space.

8. A circuit board bracket (60) for an electronic device (100), characterized in that: The invention comprises a main support (61) and a fixing frame (62) fixedly connected to the main support (61); the main support (61) and the fixing frame (62) are integrally formed structural parts; the main support (61) and the fixing frame (62) are both made of metal materials; the hardness of the material of the fixing frame (62) is greater than the hardness of the material of the main support (61); and the density of the fixing frame (62) is greater than the density of the main support (61).

9. The circuit board support (60) according to claim 8, characterized in that: The density of the main support (61) is less than 3.5 g / cm 3 ; The hardness of the material of the fixing frame (62) is in the range of 100 HV to 400 HV.

10. The circuit board support (60) according to claim 8 or 9, characterized in that: The circuit board bracket (60) further comprises a connection layer (63), wherein the connection layer (63) is fixedly connected between the fixing frame (62) and the main bracket (61); The connecting layer (63) includes the material of the main support (61) and the material of the fixing frame (62), and along the direction from the main support (61) to the fixing frame (62), the content of the main group elements of the material of the main support (61) gradually decreases, and the content of the main group elements of the material of the fixing frame (62) gradually increases.

11. The circuit board support (60) according to claim 10, characterized in that: The thickness of the connecting layer (63) is greater than 0.1 μm; and / or The thickness of the connection layer (63) is in the range of 2 μm to 30 μm.

12. The circuit board holder (60) according to any one of claims 8 to 11, characterized in that: The thermal conductivity of the main support (61) is greater than the thermal conductivity of the fixing frame (62).

13. The circuit board holder (60) according to any one of claims 8 to 12, characterized in that: The material of the fixing frame (62) is stainless steel, titanium alloy or steel-aluminum-steel laminated composite material; and / or, The main support (61) is made of aluminum alloy, particle-reinforced aluminum-based composite material, magnesium alloy or particle-reinforced magnesium-based composite material.

14. The circuit board holder (60) according to any one of claims 8 to 13, characterized in that: The main support (61) is provided with at least one matching structure (611), wherein the matching structure (611) is a protrusion or a groove or an avoidance hole; and / or the fixing frame (62) is provided with at least one fastening hole (621).

15. An electronic device (100), characterized in that: Comprising a circuit board (30) and a shielding cover (50) according to any one of claims 1 to 7, wherein the shielding cover (50) is mounted on the circuit board (30); or A circuit board bracket (60) comprising a housing and any one of claims 8 to 14, wherein the circuit board bracket (60) is mounted on the circuit board (30); or It comprises a shell, a shielding cover (50) according to any one of claims 1 to 7, and a circuit board bracket (60) according to any one of claims 8 to 14, wherein the shielding cover (50) and the circuit board bracket (60) are both mounted on the circuit board (30).

16. A method for preparing a structural part, characterized in that: The preparation method comprises: Prepare a part to be sintered, the part to be sintered includes a frame and a powder connected to the frame, the frame is made of a first metal material, the powder is made of a second metal material, and the density of the first metal material is greater than that of the second metal material; Sintering the to-be-sintered part to form a green body, wherein the green body comprises a first part and a second part, the first part is formed by the frame, and the second part is formed by the powder; and, Processing the blank to form a structural member, wherein the structural member includes a first member and a second member fixedly connected to the first member, wherein the first member is formed by the first part, and the second member is formed by the second part; Wherein, the structural member is the shielding cover according to any one of claims 1 to 7, the first member is a flange, and the second member is a cover body; or, the structural member is the circuit board bracket according to any one of claims 8 to 14, the first member is a fixing frame, and the second member is a main bracket.

17. The preparation method according to claim 16, characterized in that: In the step of "sintering the to-be-sintered part", the powder and the frame diffuse with each other to form a diffusion layer, the diffusion layer is connected between the first part and the second part, and the first part, the second part and the diffusion layer constitute the blank; The structural member further includes a connection layer, and the connection layer includes a first metal material and a second metal material.

18. The preparation method according to claim 16 or 17, characterized in that: Sintering the to-be-sintered part by using a hot isostatic pressing sintering process; The pressure P1 of the hot isostatic pressing sintering process satisfies: P1 ≥ 100Mpa; The temperature T1 of the hot isostatic pressing sintering process satisfies: 500°C≤T1≤660°C; The time t1 of the hot isostatic pressing sintering process satisfies: 2h≤t1≤5h.

19. The preparation method according to any one of claims 16 to 18, characterized in that: After the step of "sintering the to-be-sintered part to form a green body", and before the step of "processing the green body to form a structural part", the preparation method further comprises: Performing a solution treatment on the blank; Cooling the green body to room temperature; The green body is subjected to aging treatment.

20. The preparation method according to claim 19, characterized in that: The powder material is made of aluminum alloy or particle-reinforced aluminum-based composite material, the solution temperature T2 of the solution treatment satisfies: 500°C≤T2≤550°C, and the solution time t2 satisfies: 15min≤t2≤60min; and / or The temperature T3 of the aging treatment satisfies: 170°C≤T3≤200°C, and the aging time t3 satisfies: 4h≤t3≤24h.

21. The preparation method according to claim 19, characterized in that: The powder material is a magnesium alloy or a particle-reinforced magnesium-based composite material, the solution temperature T2 of the solution treatment satisfies: 380° C.≤T2≤420° C., and the solution time t2 satisfies: 0.5h≤t2≤12h; and / or The temperature T3 of the aging treatment satisfies: 180°C≤T3≤220°C, and the aging time t3 satisfies: 1h≤t3≤8h.

22. The preparation method according to any one of claims 16 to 21, characterized in that: In the step of "preparing a part to be sintered", the preparation method comprises: The powder is compacted using a cold isostatic pressing process to form a block of the powder.

23. The preparation method according to claim 22, characterized in that: The pressure P4 of the cold isostatic pressing process satisfies: P4 ≥ 100 MPa, and the time t4 of the cold isostatic pressing process satisfies: 1 h ≤ t4 ≤ 3 h.

24. The preparation method according to any one of claims 16 to 23, characterized in that: The structural member is a shielding cover according to any one of claims 1 to 7, and a wetting angle of solder paste on the surface of the first metal material is less than or equal to 40°; and / or The structural member is a circuit board bracket according to any one of claims 8 to 14, and the hardness of the first metal material is in the range of 100 HV to 400 HV; and / or The density of the second metal material is less than 3.5 g / cm 3 .

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