Middle frame forming method, middle frame, and electronic device

Abstract

A middle frame forming method, a middle frame, and an electronic device, relating to the technical field of electronics. In the method, a first plate is disposed in an accommodating recess of a base body, a second plate is stacked on the first plate, an annular gap is reserved between at least the first plate and a second component part of the base body, and welding is performed along the gap to form a first welding region between at least the first plate and the base body. The second plate applies pressure to the first plate to reduce welding-induced deformation of the first plate. Then, the second plate is removed, and a connection structure between a first component part and the second component part on the base body is removed, so that the second plate and the first component part are separated from the first plate, and the first plate and the second component part are retained to form a middle plate and a frame. It is not necessary to completely cut through the second plate and the first component part for removal, thereby reducing or avoiding deformation of the first plate caused by pressure during cutting. The first plate is processed into an ultra-thin plate, the formed middle plate also has a high finished product yield, and the middle frame having the ultra-thin middle plate is obtained.

Description

Mid-frame molding method, mid-frame and electronic devices

[0001] This application claims priority to Chinese Patent Application No. 202510148723.4, filed on February 10, 2025, entitled "Method for forming a middle frame, middle frame and electronic device", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of electronic technology, and in particular to a method for forming a mid-frame, a mid-frame, and an electronic device. Background Technology

[0003] With the continuous development and updating of electronic technology, convenient mobile terminal devices, such as mobile phones, tablets, and laptops, have become increasingly common in people's daily lives. To meet users' high usage demands, these electronic devices are gradually developing towards thinner and lighter designs.

[0004] Electronic devices may include a display screen, a mid-frame, and a back cover. Along the thickness direction of the electronic device, the display screen and back cover are located on opposite sides of the mid-frame. The mid-frame may include a middle plate and a frame, with the frame surrounding the middle plate. The frame and middle plate can form a cavity where components such as batteries and motherboards can be housed. The mid-frame is typically manufactured using computer numerical control (CNC) to form a unibody structure. For example, using a flat substrate, the frame, middle plate, and cavity are formed through CNC cutting to obtain a unibody mid-frame. However, due to manufacturing limitations, the middle plate of the mid-frame is relatively thick and difficult to further thin, failing to meet the thinning design requirements of electronic devices. Summary of the Invention

[0005] This application provides a method for forming a mid-frame, a mid-frame, and an electronic device, which can obtain an ultra-thin mid-plate, thereby increasing the thickness space of the electronic device's cavity and meeting the thinning design requirements of the electronic device.

[0006] The first aspect of this application provides a method for forming a mid-frame, including:

[0007] A substrate, a first plate, and a second plate are provided. The substrate includes a first segment and a second segment. A portion of the second segment is disposed around the first segment, and a portion of the second segment protrudes from one side of the first segment. The second segment and the first segment form a receiving groove.

[0008] The first plate is placed in the receiving groove, and the second plate is stacked on the first plate, with at least a gap between the outer side of the first plate and the inner side of the second part.

[0009] Welding is performed along the seam to form a first weld zone between at least the first plate and the substrate.

[0010] Remove the second sheet material.

[0011] Remove the portion of the structure located between the first and second parts of the substrate to disconnect the first and second parts, and remove the first part as a whole.

[0012] The first sheet material forms at least a middle plate, and the second split part forms at least a border to form an integral middle frame. The at least a border surrounds the at least a middle plate, and the at least a border and the at least a middle plate form a first receiving cavity.

[0013] The above method utilizes the substrate and the first plate to form at least a partial frame and at least a partial middle plate, thereby forming a middle frame. During the welding process, the second plate can exert a certain pressure on the first plate, which helps to reduce the deformation effect of welding on the first plate. In the example where there is a gap between the first plate, the second plate, and the substrate, the first plate is located between the second plate and the first segment of the substrate. The pressure during the welding process (such as the pressure generated by the welding device) is mostly applied directly to the second plate and the second segment of the substrate, which can reduce the deformation effect on the first plate.

[0014] During the process of removing the second sheet metal and the first segment to retain the first sheet metal and the second segment, the portion of the structure connecting the second sheet metal within the first welding area is removed, thus disconnecting the second sheet metal from the substrate (or the second sheet metal can be directly removed without cutting). Removing the portion of the structure connecting the first and second segments on the substrate, thus disconnecting the first and second segments, allows the second sheet metal and the first segment to be separated from the first sheet metal (and the second segment of the substrate) respectively, retaining the first sheet metal and the second segment to form at least a portion of the middle plate and at least a portion of the frame, respectively, enclosing the first receiving cavity. This eliminates the need for cutting the entire area of ​​the second sheet metal and the first segment, resulting in a small cutting area. Furthermore, the pressure during the cutting process is mainly applied at the points where the edge of the second sheet metal meets the first welding area and where the edge of the first segment meets the second segment, thus reducing or avoiding the impact of the pressure during the cutting process on the first sheet metal and minimizing or avoiding deformation problems.

[0015] This allows the first board to be an ultra-thin sheet, resulting in at least a portion of the middle board with high flatness and a high yield rate. Thus, while maintaining a high yield rate, the thickness of the middle board can be further reduced, resulting in an ultra-thin middle frame. This facilitates increasing the thickness space of the accommodating cavity (such as the first accommodating cavity), enabling thinner designs for electronic devices.

[0016] In one possible implementation, placing the first plate within the receiving groove and stacking the second plate on top of the first plate includes:

[0017] The second plate is positioned in the receiving groove, and there is a gap between the outer side of the first plate, the outer side of the second plate, and the inner side of the second split part.

[0018] Welding along the seam to form a first weld zone between at least the first plate and the substrate includes: welding the first plate, the second plate, and the substrate along the seam to form a first weld zone between the first plate, the second plate, and the substrate.

[0019] Removing the second plate includes removing the portion of the structure connected to the second plate within the first welding zone to disconnect the second plate from the substrate.

[0020] During the welding process, the first plate, the second plate, and the substrate are connected in the first welding area. The second plate applies pressure to the first plate, reducing the deformation of the first plate caused by welding. Furthermore, the first plate is located between the second plate and the first segment of the substrate. The pressure applied by the welding device during welding is primarily directed onto the second segment of the second plate and the substrate, minimizing pressure-induced deformation of the first plate and improving the flatness and yield of the finished product.

[0021] In one possible implementation, stacking the second plate on the first plate includes: covering a portion of the first plate with the second plate to expose at least part of the gap between the first plate and the substrate.

[0022] After the second plate is superimposed on the first plate, and before welding along the seam, the method further includes: pressing the second plate against the first plate.

[0023] Welding along the seam to form a first weld zone between at least the first plate and the substrate includes: welding the first plate and the substrate along the seam to form a first weld zone between the first plate and the substrate.

[0024] During the welding process, the second sheet material presses against the first sheet material to achieve a pressure effect, which reduces the deformation of the first sheet material during welding. The second sheet material can be directly removed without cutting or other processes, and there is no need to cut or remove the entire area of ​​the second sheet material and the first segment. This effectively reduces or avoids the impact of pressure on the second sheet material during the cutting process, and reduces or avoids deformation problems of the first sheet material. Under the condition of ensuring a high yield rate, the thickness of the middle plate can be further reduced, resulting in an ultra-thin middle frame.

[0025] Furthermore, there is no connection between the second plate and the first plate or the substrate. Welding the second plate will not affect it. The second plate can be reused, which helps to reduce processing costs.

[0026] In one possible implementation, welding along the seam includes:

[0027] The friction stir welding process is used to weld along the seam, and the side where the first plate is located is the forward side of the friction stir welding process.

[0028] For example, the welding apparatus for friction stir welding may include a stirring head that rotates at high speed. The rotating stirring head generates frictional heat by rubbing against at least the second segment of the first plate and the substrate, allowing the stirring head to be inserted into the gap. The stirring head can move along the gap while rotating at high speed, causing the flowing first plate, substrate, etc., to fuse together, and atomic-level bonding occurs between the materials to form an integral structure. This forms a first welding zone at least between the first plate and the substrate, connecting the first plate and the substrate at least at the location of the first welding zone, thus achieving a welded connection between the first plate and the substrate.

[0029] The "advancing side" refers to the side where the rotation direction of the stirring head is the same as the movement direction of the stirring head along the gap. The material on the advancing side is propelled by the stirring head, resulting in greater fluidity and improving welding quality. Positioning the side containing the first plate as the advancing side and the side containing the second sub-section as the retreating side improves the welding quality between the first plate and the substrate, reduces the deformation of the first plate (near the first welding area) caused by welding, improves the flatness of the intermediate plate formed from the first plate, and ultimately increases the yield rate of the finished product.

[0030] In one possible implementation, after providing the substrate and before placing the first plate in the receiving groove, the method further includes:

[0031] A first groove is formed at the edge where the first segment meets the second segment. At least a portion of the first groove is a blind groove on the inner side of the first segment, and the first groove surrounds the inner side of the second segment.

[0032] Removing the portion of the structure located between the first and second parts of the substrate includes: removing the portion of the structure located on the side of the first groove away from the first plate material on the first part.

[0033] A first groove is formed on the first segment, and a portion of the structure on the side of the first segment opposite to the first plate material is removed by cutting, thereby separating the first segment from the second segment. During the cutting process, the first plate material is not cut, and burrs or other structures are not formed at the junction of the first plate material and the second segment (first welding area). This simplifies the post-forming process of the first plate material and reduces or avoids deformation problems caused by post-forming. Furthermore, it further reduces deformation of the first plate material during cutting, which helps improve the flatness of the formed plate and increases the yield of the finished product.

[0034] In one possible implementation, the second split includes a first part and a second part, the first part protruding from one side of the second part, and the second part surrounding the outside of the first split.

[0035] Forming at least a partial border for the second segment includes: a first frame forming a border for the first segment, a second frame forming a border for the second segment, and the second frame and the middle plate forming a first receiving cavity.

[0036] The gap is formed at least between the first plate and the first part of the second segment. During the welding process, the degree of plastic deformation caused to the first part is greater than that to the second part. The first part with greater plastic deformation forms a first frame with a smaller thickness requirement, while the second part with less plastic deformation forms a second frame with a larger thickness requirement. If most of the structure is removed from the first part with more severe deformation by cutting or other means, the remaining small part can form the first frame, which helps to improve the flatness of the second frame and the first frame and improve the yield of finished products.

[0037] In one possible implementation, the substrate further includes a third sub-part located on one side of the first and second sub-parts.

[0038] After welding along the seam, the method further includes:

[0039] The welding endpoint structure is formed within the third sub-section.

[0040] A through hole is formed at the location of the weld endpoint structure to remove the weld endpoint structure.

[0041] The third segment is formed into a middle plate and a side plate, and the side plate and the middle plate together form a second receiving cavity, with the through hole located inside the second receiving cavity.

[0042] After the stirring head moves around the seam once to weld the first plate to the substrate, it can be moved to the third segment, where welding stops. The stirring head is then pulled out, creating a hole structure within the third segment. This hole structure serves as the welding endpoint. The welding endpoint structure is then removed by forming a through-hole, which can be used to accommodate components such as cameras. This design rationally designs the frame structure, meeting the assembly requirements for components like cameras, while avoiding the welding endpoint structure affecting the shape of the second segment, thus reducing the difficulty of frame structural design and molding, and facilitating implementation.

[0043] In one possible implementation, the elastic modulus of the first plate is greater than or equal to the elastic modulus of the second plate and the matrix. This allows at least a portion of the middle plate formed from the first plate to possess high rigidity and hardness, ensuring the mechanical properties of the middle plate and the middle frame, and guaranteeing the strength and reliability of the middle frame, while achieving at least a partial thinning of the middle plate.

[0044] In one possible implementation, the elastic modulus of the first sheet material is greater than or equal to 90 GPa. This ensures that the middle plate formed from the first sheet material has high hardness and rigidity, giving the middle frame good mechanical properties.

[0045] In one possible implementation, the elastic modulus of the first plate can be greater than or equal to 100 GPa, which helps to further enhance the mechanical strength of the molded middle plate and make the middle frame more reliable.

[0046] In one possible implementation, the yield strength of the first sheet material is greater than or equal to the yield strength of the second sheet material and the matrix material. This ensures the rigidity and hardness of at least a portion of the middle plate formed by the first sheet material, thus guaranteeing the mechanical properties of the middle frame.

[0047] In one possible implementation, the micro Vickers hardness of the first sheet material is greater than or equal to the micro Vickers hardness of the second sheet material and the matrix. This ensures that at least a portion of the middle plate formed from the first sheet material possesses high rigidity and hardness, achieving thinning of the middle plate while maintaining the mechanical properties of the middle frame.

[0048] In one possible implementation, the material of the first plate includes one or more of aluminum-based composite materials and magnesium-based composite materials. The middle plate formed using the first plate can have higher hardness and rigidity, ensuring the high strength and high reliability of the middle frame.

[0049] In one possible implementation, the material of the first sheet also includes reinforcing materials that can further enhance the strength and rigidity of the formed middle sheet, giving the middle frame higher mechanical properties.

[0050] In one possible implementation, the reinforcing material includes ceramic particles. This provides a significant reinforcing effect, enabling the mid-plate and mid-frame to have superior mechanical strength, while also being relatively inexpensive.

[0051] In one possible implementation, the materials of the second sheet and the substrate include one or more of metal composite materials, aluminum alloy materials, and magnesium alloy materials. This results in a frame with good mechanical properties and aesthetics.

[0052] In one possible implementation, the thickness of at least a portion of the middle plate is less than or equal to 0.3 mm. This effectively reduces the thickness of at least a portion of the middle plate, which is beneficial for increasing the space of the first receiving cavity in the thickness direction and meeting the thinning design requirements of electronic devices.

[0053] In one possible implementation, at least a portion of the middle plate has a thickness of less than or equal to 0.2 mm, making at least a portion of the middle plate thinner, further increasing the space of the first receiving cavity, and making it more conducive to achieving a thinner design for electronic devices.

[0054] In one possible implementation, the thickness of at least part of the middle plate is less than or equal to 0.15 mm, which realizes an ultra-thin design of at least part of the middle plate, allowing the first receiving cavity to have a larger space, and also realizing an ultra-thin design of the electronic device.

[0055] A second aspect of this application provides a mid-frame, including a mid-plate and a side frame, the side frame surrounding the mid-plate, at least a portion of the side frame and at least a portion of the mid-plate being welded together to form an integral structural component, a second welding area being provided at the position where at least a portion of the mid-plate and at least a portion of the side frame meet, and at least a portion of the side frame and at least a portion of the mid-plate forming a first receiving cavity.

[0056] A second welding zone is formed between at least a portion of the frame and at least a portion of the middle plate by welding. Within this second welding zone, the materials of at least a portion of the middle plate and at least a portion of the frame are mixed together to achieve atomic-level bonding, forming an integral structure. This allows the at least a portion of the middle plate and at least a portion of the frame to be connected at the second welding zone, forming an integral middle frame. The at least a portion of the middle plate within this middle frame has high flatness and a thinner thickness, enabling thickness reduction while maintaining middle plate quality. This facilitates increasing the thickness space of the internal cavities (such as the first receiving cavity) within the middle frame, thus enabling thinner designs for electronic devices.

[0057] In this design, at least a portion of the middle plate has a thickness of less than or equal to 0.3 mm. This thinner thickness of at least a portion of the middle plate allows for a larger thickness space in the first receiving cavity, thus facilitating the thinning design requirements of electronic devices.

[0058] In one possible implementation, at least a portion of the middle plate has a thickness of less than or equal to 0.2 mm, making at least a portion of the middle plate thinner, further increasing the space of the first receiving cavity, and making it more conducive to achieving a thinner design for electronic devices.

[0059] In one possible implementation, the thickness of at least a portion of the middle plate is less than or equal to 0.15 mm. This ultra-thin design of at least a portion of the middle plate allows for a larger space in the first receiving cavity and also enables ultra-thin designs for electronic devices.

[0060] In one possible implementation, at least a portion of the frame includes a first frame and a second frame. A portion of the first frame surrounds at least a portion of the middle plate and protrudes in the thickness direction from one side of the middle plate. The first frame and the middle plate can form a cavity, such as one that can accommodate structural components of a display screen. The second frame protrudes in the thickness direction from the other side of the middle plate, and the second frame and the middle plate form a first receiving cavity. Both the first and second frames have second welding areas. The elemental composition of the first frame located within the second welding area differs from that of the second frame located within the second welding area.

[0061] In one possible implementation, the second frame has a second groove on the side facing the first receiving cavity, and the second groove is located between at least a portion of the middle plate facing the first receiving cavity and a portion of the second frame. The provision of the second groove on the second frame helps to better reduce or avoid the deformation of the middle plate during the middle frame processing, ensuring that the middle plate has high flatness, and also helps to reduce processing difficulty and processing cost.

[0062] In one possible implementation, at least a portion of the middle plate and at least a portion of the frame are formed into a second welding zone by friction stir welding. The second welding zone has a notch structure after cutting. Using the aforementioned substrate, first plate, and second plate, a middle frame is prepared by the aforementioned middle frame forming method. At least the substrate and the first plate are welded together by forming a first welding zone through friction stir welding. After cutting and post-shaping processes, the substrate ultimately forms at least a portion of the frame, and the first plate forms at least a portion of the middle plate, thereby obtaining a middle frame with at least a portion of the middle plate being ultra-thin.

[0063] After cutting and post-shaping processes, a portion of the first welding area is cut away to form a second welding area, so that at least a portion of the middle plate and at least a portion of the frame are connected together through the second welding area. The second welding area has a notch structure formed by cutting and other processes.

[0064] In one possible implementation, the elastic modulus of at least a portion of the middle plate is greater than or equal to the elastic modulus of at least a portion of the frame, ensuring that the middle plate has strong rigidity and hardness, and ensuring the mechanical properties of the middle plate and the middle frame while achieving the thinning of at least a portion of the middle plate.

[0065] In one possible implementation, at least a portion of the middle plate has an elastic modulus greater than or equal to 90 GPa. This ensures the middle plate has high hardness and rigidity, giving the middle frame high mechanical properties.

[0066] In one possible implementation, at least a portion of the middle plate has an elastic modulus greater than or equal to 100 GPa, which helps to further enhance the mechanical strength of the middle plate and make the middle frame more reliable.

[0067] In one possible implementation, the yield strength of at least a portion of the middle plate is greater than or equal to the yield strength of at least a portion of the frame material. This ensures the middle plate has high rigidity and hardness, achieving at least partial thinning of the middle plate while maintaining the mechanical properties of the middle frame.

[0068] In one possible implementation, the micro Vickers hardness of at least a portion of the middle plate is greater than or equal to the micro Vickers hardness of at least a portion of the frame. This gives the middle plate high rigidity and hardness, ensuring the mechanical properties of the middle frame while achieving a thinner design.

[0069] In one possible implementation, at least part of the middle plate is made of one or more of aluminum-based composite materials and magnesium-based composite materials, which allows the middle plate to have higher hardness and rigidity, ensuring high strength and high reliability of the middle frame.

[0070] In one possible implementation, at least part of the mid-plate material also includes reinforcing materials. These reinforcing materials can further enhance the strength and rigidity of the mid-plate, giving the mid-frame superior mechanical properties.

[0071] In one possible implementation, at least part of the frame is made of one or more of the following materials: metal composite materials, aluminum alloy materials, and magnesium alloy materials, so that the frame has good mechanical properties and aesthetics.

[0072] A third aspect of this application provides an electronic device including a display screen and any of the aforementioned mid-frames, wherein the display screen is located on one side of the mid-frame. Attached Figure Description

[0073] Figure 1 is a schematic diagram of the structure of an electronic device provided in an embodiment of this application;

[0074] Figure 2 is a schematic diagram of the disassembled structure of the electronic device in Figure 1;

[0075] Figure 3 is a schematic flowchart of a mid-frame forming method provided in an embodiment of this application;

[0076] Figure 4 is a schematic diagram of the structure of a substrate, a first plate, and a second plate before assembly, according to an embodiment of this application.

[0077] Figure 5 is a cross-sectional schematic diagram of the assembly of the substrate, the first plate, and the second plate in Figure 4;

[0078] Figure 6 is a schematic diagram of the assembly of the substrate, the first plate, and the second plate in Figure 4;

[0079] Figure 7 is a schematic diagram of the substrate, first plate and second plate in Figure 6 before welding using a welding device;

[0080] Figure 8 is a cross-sectional view of the substrate, first plate and second plate in Figure 6 being welded using a welding device.

[0081] Figure 9 is a partial structural diagram of a substrate, a first plate, and a second plate after welding, according to an embodiment of this application.

[0082] Figure 10 is a schematic diagram of the substrate, the first plate, and the second plate after welding in Figure 9;

[0083] Figure 11 is a cross-sectional view of the substrate, the first plate, and the second plate after welding in Figure 10.

[0084] Figure 12 is a cross-sectional view of the welded structure of the substrate, the first plate and the second plate in Figure 11 after the cutting process.

[0085] Figure 13 is a cross-sectional view of the middle frame obtained after the substrate and the first plate in Figure 12 have undergone shaping and other processes.

[0086] Figure 14 is a schematic diagram of the middle frame in Figure 13;

[0087] Figure 14a is a schematic diagram of the structure of another substrate, first plate, and second plate before assembly according to an embodiment of this application;

[0088] Figure 14b is a cross-sectional schematic diagram of welding the substrate and the first plate in Figure 14a using a welding device;

[0089] Figure 14c is a partial structural diagram of another substrate, first plate and second plate after welding according to an embodiment of this application;

[0090] Figure 14d is a cross-sectional view of the first plate and the substrate in Figure 14c after welding and the removal of the second plate.

[0091] Figure 14e is a schematic diagram of an assembly of a substrate, a first plate, a second plate, and an outer frame provided in an embodiment of this application;

[0092] Figure 15 is a structural schematic diagram of the welding device used in Figure 8 to weld the base, the first plate and the second plate;

[0093] Figure 16 is a partial flowchart of a method for forming a middle frame according to an embodiment of this application;

[0094] Figure 16a is a partial flowchart of another method for forming a middle frame according to an embodiment of this application;

[0095] Figure 16b is a cross-sectional view of another middle frame provided in an embodiment of this application;

[0096] Figure 17 is a partially enlarged cross-sectional view of the middle frame in Figure 14.

[0097] Explanation of reference numerals in the attached drawings: 100 - Electronic device; 110 - Housing; 10 - Middle frame; 11 - Middle plate; 111 - Through hole; 12 - Frame; 121 - First frame; 122 - Second frame; 1221 - Second groove; 131 - First receiving cavity; 14 - Cavity; 20 - Back cover; 120 - Display screen; 130 - Camera; 140 - Interface; 150 - Sound outlet; 160 - Sound pickup port; 101 - Base; 1011 - First sub-section; 1111 - First groove; 1012 - Second sub-section; 1112 - First part; 1212 - Second part; 1011a - Receiving groove; 1013 - Third sub-section; 1014 - Fourth sub-section; 102 - First plate; 103 - Second plate; 200 - Welding device; 201 - Stirring head. Detailed Implementation

[0098] The terminology used in the implementation section of this application is for the purpose of explaining specific embodiments of this application only, and is not intended to limit this application.

[0099] This application provides an electronic device, which may include, but is not limited to, mobile phones, tablet personal computers, laptops, cameras, ultra-mobile personal computers (UMPCs), handheld computers, walkie-talkies, netbooks, POS machines, personal digital assistants (PDAs), wearable devices (such as watches, bracelets, smartwatches, smart bracelets, etc.), virtual reality (VR) devices (such as VR glasses, VR headsets, etc.), augmented reality (AR) devices (such as AR glasses, AR headsets, etc.), mixed reality (MR) devices, in-vehicle devices, surveillance camera equipment, etc.

[0100] The electronic device can be a non-foldable device. For example, a mobile phone can be a candybar phone. For instance, a mobile phone may include a casing, which can be the main supporting structure of the phone. The casing can be flat and cannot be folded, preventing the entire electronic device from folding.

[0101] Alternatively, the electronic device can also be a foldable electronic device. For example, taking a mobile phone as an example, the mobile phone can be a foldable foldable phone. For instance, a mobile phone can include at least two housings, which can rotate relative to each other and fold or unfold, enabling the electronic device to fold or unfold.

[0102] In the example of a foldable electronic device, such as a foldable phone, the foldable phone can be a foldable phone with the display folding outwards. Alternatively, the foldable phone can be a foldable phone with the display folding inwards. Or, the foldable phone can be a foldable phone with part of the display folding inwards and part of the display folding outwards, etc.

[0103] In this embodiment of the application, a mobile phone is used as the electronic device, such as a candybar mobile phone, for example.

[0104] Figure 1 is a schematic diagram of the structure of an electronic device provided in an embodiment of this application.

[0105] Referring to Figure 1, the electronic device 100 may include a housing 110, which can serve as the main load-bearing structural component of the electronic device 100. For example, the housing 110 may have a receiving cavity (not shown in the figure) for assembling and housing various components of the electronic device 100.

[0106] Figure 2 is a schematic diagram of the disassembled structure of the electronic device in Figure 1.

[0107] Referring to Figure 2, the electronic device 100 may further include a display screen 120, which may be disposed on one side of the housing 110. The display screen 120 is used to display information and provide an interactive interface for the user, and the side of the display screen 120 facing away from the housing 110 may serve as the display surface of the electronic device 100.

[0108] The display screen 120 may include, but is not limited to, a liquid crystal display (LCD), an organic light-emitting diode (OLED) display, a micro organic light-emitting diode (MOLED) display, an active-matrix organic light-emitting diode (AMOLED) display, a light-emitting diode (LED) display, a mini organic light-emitting diode (Mini LED) display, a micro organic light-emitting diode (Micro LED) display, a quantum dot light-emitting diode (QLED) display, etc.

[0109] Referring to Figures 1 and 2, the housing 110 may include a middle frame 10 and a rear cover 20. The middle frame 10 may surround one side of the rear cover 20. The rear cover 20 may be a plate-like structural component, and the middle frame 10 may be a frame structural component. The outer contour shape of the rear cover 20 may match the outer contour shape of the middle frame 10. For example, the outer contour shape of the rear cover 20 may be a rectangle-like shape, and the outer contour shape of the middle frame 10 may also be a rectangle-like shape, so that the outer contour shape of the entire housing 110 may be a rectangle-like shape as shown in Figure 1.

[0110] Of course, in some other examples, the outer contours of the back cover 20 and the middle frame 10 can also be regular or irregular shapes such as squares, circles, ellipses, and rounded rectangles.

[0111] In this embodiment of the application, taking the outer contour shape of the middle frame 10 as a rectangle as an example, for ease of description, as shown in Figures 1 and 2, the width direction of the middle frame 10 is the x-direction, the length direction of the middle frame 10 is the y-direction, and the thickness direction of the middle frame 10 is the z-direction.

[0112] The width, length, and thickness directions of the electronic device 100 can be consistent with the width, length, and thickness directions of the middle frame 10. It is understood that the length, width, and thickness in the embodiments of this application are for descriptive convenience only and do not imply any limitation on the dimensions; for example, the length can be greater than, equal to, or less than the width.

[0113] Referring to Figure 2, the display screen 120 can be located on the side of the middle frame 10 facing away from the back cover 20, that is, along the thickness direction (z direction). The display screen 120 and the back cover 20 can be fixed to opposite sides of the middle frame 10, respectively. The back cover 20 can serve as the exterior cover of the back of the electronic device 100. In this embodiment, the display surface of the display screen 120 in the electronic device 100 can serve as the front of the electronic device 100, and the side of the back cover 20 facing away from the display screen 120 can serve as the back of the electronic device 100.

[0114] The middle frame 10 may include a middle plate 11 and a frame 12. The middle plate 11 may be a flat plate-like structure, and the frame 12 may be a ring-like frame structure. The frame 12 may surround the middle plate 11, forming a receiving cavity for the housing 110. Along the thickness direction (z-direction), the display screen 120 and the back cover 20 may be respectively mounted on both sides of the frame 12.

[0115] For example, the outer surface of the frame 12 (the side facing away from the receiving cavity) may include a curved surface to improve the aesthetics of the frame 12.

[0116] In some examples, as shown in Figure 2, the receiving cavity can be located on the side of the middle plate 11 facing the rear cover 20, and the rear cover 20 can close the receiving cavity of the middle frame 10 to protect the components located within the receiving cavity. It should be noted that the side of the middle plate 11 facing the display screen 120 can also have a cavity (not shown in the figure). For example, when the display screen 120 is assembled with the frame 12, this cavity can be used to accommodate the structural components of the display screen 120.

[0117] In some other examples, the receiving cavity may also be located on the side of the middle plate 11 facing the display screen 120, and the display screen 120 may close the receiving cavity of the middle frame 10.

[0118] In some examples, the electronic device 100 may also include a camera 130 (as shown in Figure 1), which is used to perform functions such as taking pictures. The camera 130 may be at least partially mounted and housed in the receiving cavity of the mid-frame 10.

[0119] The number of cameras 130 can be one, or the number of cameras 130 can be multiple, to meet different shooting needs.

[0120] For example, camera 130 can be a rear-facing camera, such as the light inlet of camera 130 being located on the back of electronic device 100. For instance, continuing to refer to FIG2, a light-transmitting hole 21 can be provided on the back cover 20. The camera (not shown in the figure) can be located within the receiving cavity of the mid-frame 10, such as the camera being fixed to the mid-plate 11 of the mid-frame 10, and the light inlet of the camera facing the light-transmitting hole 21 on the back cover 20, so that light can be emitted into the camera through the light-transmitting hole 21 on the back cover 20.

[0121] Alternatively, in some examples, the camera may be partially located inside the receiving cavity, with part of the camera extending out of the receiving cavity through a light-transmitting hole 21 on the rear cover 20, allowing light to shine into the camera.

[0122] In some examples, as shown in Figure 2, a through hole 111 can be provided on the middle plate 11. The camera is fixed on the middle plate 11, and part of the camera can be located in the through hole 111, which improves the integration of the camera and the middle plate 11, reduces the space occupied by the camera and the middle plate 11 in the thickness direction (z direction), and helps to achieve the thickness reduction of the electronic device 100.

[0123] The camera can also be a front-facing camera, such as the camera's light inlet being located on the front of the electronic device 100. For example, a light-transmitting hole (not shown) can be provided on the display screen 120, and the camera can be located inside the housing 110's receiving cavity. The camera's light inlet can face the light-transmitting hole on the display screen 120, allowing light to shine into the camera through the light-transmitting hole on the display screen 120.

[0124] Alternatively, in some examples, the display screen 120 may not have a light-transmitting hole, and the light inlet of the camera may face the display screen 120, allowing light to pass through the display screen 120 and illuminate the camera.

[0125] In some examples, the electronic device 100 may also include a main circuit board and a battery (not shown), which may be housed within a receiving cavity of the middle frame 10, for example, the main circuit board and the battery may be fixedly mounted on the middle plate 11. The main circuit board may include a processor, a controller, a memory, etc.

[0126] The electronic device 100 may also include a battery, a charging management module, and a power management module (not shown in the figure), which may also be assembled and housed within the receiving cavity of the middle frame 10.

[0127] The charging management module receives charging input from the charger. The charger can be a wireless charger or a wired charger. In some wired charging examples, the frame 12 may have an interface 140 (as shown in Figure 1), which can be used to connect the charger. The charging management module can receive the charging input from the wired charger through the interface 140.

[0128] In some wireless charging embodiments, the charging management module can receive wireless charging input via the wireless charging coil of the electronic device 100. The charging management module can charge the battery and also supply power to the electronic device 100 via the power management module.

[0129] The interface 140 on the frame 12 can also be used to realize data transmission between the electronic device 100 and external devices, for example, it can also be used to connect headphones, projection devices, etc. For example, the interface 140 enables external devices to be electrically connected to the processor on the main circuit board.

[0130] The power management module connects the battery, charging management module, and processor. It receives input from the battery and / or charging management module to power the processor, memory, display, camera, and other components. The power management module can also monitor parameters such as battery capacity, battery cycle count, and battery health status (leakage current, impedance).

[0131] In some examples, the power management module may be located within the processor on the main board. In other examples, the power management module and the charging management module may be located in the same device.

[0132] In some examples, the electronic device 100 may also include a speaker (not shown), which enables the electronic device 100 to play audio and other sound functions. The speaker may be housed within a receiving cavity mounted in the mid-frame 10.

[0133] A sound outlet 150 can be provided on the frame 12 (as shown in Figure 1). The speaker inside the cavity can communicate with the external environment through the sound outlet 150. The speaker can convert electrical signals into sound signals to emit sound. The sound is transmitted to the external environment through the sound outlet 150 to achieve playback.

[0134] The electronic device 100 may also include a microphone (not shown in the figure), which can meet the sound pickup requirements of the electronic device 100 and enable functions such as voice control and communication. The microphone can be housed within a receiving cavity of the mid-frame 10.

[0135] A pickup port 160 can be provided on the frame 12 (as shown in Figure 1). The pickup port 160 can be connected to the microphone in the cavity. The sound of the external environment can be picked up by the pickup port 160 and transmitted to the microphone. The microphone can realize the conversion between sound signals and electronic signals, thereby realizing functions such as voice control and communication.

[0136] It is understood that the structures illustrated in the embodiments of this application do not constitute a specific limitation on the electronic device 100. In other embodiments of this application, the electronic device 100 may include more or fewer components than illustrated, or combine some components, or split some components, or arrange the components differently. For example, the electronic device 100 may also include structural components such as sensors, communication modules, speakers, microphones, and flashlights.

[0137] For example, the number of receiving cavities within the middle frame 10 can be one, and the various devices of the electronic device 100 can be arranged within this one receiving cavity. Alternatively, the number of receiving cavities can also be multiple, for example, Figure 2 illustrates an example of multiple receiving cavities within the middle frame 10, such as a first receiving cavity 131, a second receiving cavity 132, a third receiving cavity 133, and a fourth receiving cavity 134.

[0138] The first receiving cavity 131, the second receiving cavity 132, the third receiving cavity 133, and the fourth receiving cavity 134 are respectively used to accommodate various components of the assembled electronic device 100. For example, the first receiving cavity 131 can be used to accommodate the battery of the electronic device 100, and the first receiving cavity 131 can serve as part or all of the battery compartment of the electronic device 100. The second receiving cavity 132 can be used to accommodate the camera of the electronic device 100, such as the aforementioned through hole 111 on a portion of the middle plate 11 within the second receiving cavity 132. The third receiving cavity 133 and the fourth receiving cavity 134 can be used to accommodate other structural components of the electronic device 100, such as speakers, microphones, etc.

[0139] Among them, the middle plate 11 and the frame 12 can be integrally formed, so that the middle frame 10 can be an integral structural component. Compared with forming the middle plate 11 and the frame 12 separately and then fixing and assembling them by means of threaded connection to form the middle frame, it can save the design and assembly space of screws, etc., which is conducive to the thinning design of electronic device 100.

[0140] Currently, the commonly used molding method for unibody mid-frames is computer numerical control (CNC) cutting. For example, using a flat metal block as the base material, the metal block includes a first surface and a second surface facing away from each other. CNC cutting is performed on the first surface of the metal block to form cavities for accommodating structural components of the display screen. CNC cutting is performed on the second surface of the metal block to form the aforementioned cavities, such as the first, second, third, and fourth cavities, thereby forming the mid-frame and bezel.

[0141] Understandably, to form the middle plate, frame, and the aforementioned cavities and receiving chambers, the first and second surfaces of the metal block must be machined. During the machining process, a certain pressure is applied to the metal block. When the formed middle plate is thin, it will undergo severe deformation under pressure, resulting in poor flatness and low yield. This limits the thickness of the middle plate in the frame. The one-piece middle frame, usually formed by CNC machining, typically has a plate thickness of 0.35mm or more, making it impossible to further reduce the thickness of the middle plate. This makes it difficult to further increase the thickness space of the receiving chamber or to further reduce the thickness of electronic devices.

[0142] Based on this, embodiments of this application provide a method for forming a middle frame and a middle frame. This method utilizes a substrate, a first plate, and a second plate. The first plate is placed within a receiving groove in the substrate, and the second plate is superimposed on the first plate. The first plate is located between a first segment of the substrate and the second plate, creating a gap between at least the outer surface of the first plate and the inner surface of the second segment of the substrate. Welding along the annular gap forms a first welding area with an overall annular contour between at least the first plate and the substrate. The second plate can be removed, for example, by removing a portion of the structure connected to the second plate within the first welding area, thus detaching the second plate from the substrate and removing it entirely, or by directly removing the second plate. Removing a portion of the structure on the substrate located between the first and second segments allows the first and second segments to be disconnected, allowing the first segment to be removed entirely, while retaining the first plate and the second segment to form at least a partial middle plate and at least a partial frame, respectively, enclosing a first receiving cavity. During the welding process, the second plate can exert a certain pressure on the first plate, which helps to reduce the deformation of the first plate during welding. In examples where there is a gap between the first plate, the second plate, and the substrate, the pressure generated by the welding device is mostly applied directly to the second plate and the second part of the substrate, which can also reduce the deformation of the first plate.

[0143] In the process of removing the second plate and the first segment while retaining the first plate and the second segment, removing the portion of the structure connected to the second plate within the first welding area, or directly removing the second plate and the portion of the structure connecting the first and second segments on the substrate, allows the second plate and the first segment to be separated from the first plate (and the second segment of the substrate). This eliminates the need for cutting away the entire area of ​​the second plate and the first segment, resulting in a small cutting area. Furthermore, the pressure during the cutting process is primarily applied at the points where the edge of the second plate meets the first welding area and where the edge of the first segment meets the second segment, thus reducing or avoiding the impact of the cutting pressure on the first plate and minimizing or avoiding deformation issues. This results in an ultra-thin first plate, and at least a portion of the resulting middle plate can have high flatness and a high yield rate. Therefore, while maintaining a high yield rate, the thickness of the middle plate can be further reduced, resulting in an ultra-thin middle frame. This facilitates increasing the thickness space of the accommodating cavity (such as the first accommodating cavity) and enabling thinner designs for electronic devices.

[0144] Figure 3 is a schematic flowchart of a mid-frame forming method provided in an embodiment of this application.

[0145] Referring to Figure 3, the method may include steps S101 to S106. This method can obtain an ultra-thin integrated mid-frame while ensuring the yield of finished products.

[0146] Taking the preparation of the middle frame 10 of a mobile phone using this method as an example, the above steps of the method are illustrated in turn.

[0147] Step S101: Provide a substrate, a first plate, and a second plate.

[0148] In this embodiment, at least a portion of the substrate is used to form the border of the middle frame, and the first plate is used to form at least a portion of the middle plate of the middle frame. The outer contour shape of the substrate can be consistent with the outer contour shape of the border. Figure 4 is a structural schematic diagram of the substrate, the first plate, and the second plate before assembly according to an embodiment of this application. Referring to Figure 4, taking the outer contour shape of the border as a rectangle as an example, the outer contour shape of the substrate 101 can also be a rectangle.

[0149] The outer contour shape of the first plate 102 can be consistent with the outer contour shape of the middle plate of the middle frame, and the outer contour shape of the second plate 103 can be consistent with the outer contour shape of the first plate 102. For example, if the outer contour shape of the middle plate is a rectangular plate, the outer contour shapes of the first plate 102 and the second plate 103 can also be rectangular plates.

[0150] For example, the material of the substrate 101 may include an aluminum alloy, so that the formed border is made of aluminum alloy. Of course, in some other examples, the material of the substrate 101 may also be one or more of other types of metal materials, metal alloy materials, metal composite materials, etc. For example, the material of the substrate 101 may also be a magnesium alloy, etc.

[0151] In some examples, the material of the first plate 102 may be different from that of the substrate 101. For example, the elastic modulus of the first plate 102 may be greater than or equal to the elastic modulus of the second plate 103 and the substrate 101, so that at least part of the middle plate formed by the first plate 102 can have strong rigidity and hardness. Under the condition of thinning at least part of the middle plate, the mechanical properties of the middle plate and the middle frame are guaranteed, and the strength and reliability of the middle frame are guaranteed.

[0152] For example, the elastic modulus of the first plate 102 can be greater than or equal to 90 GPa. This ensures that the middle plate formed from the first plate 102 has high hardness and rigidity, giving the middle frame good mechanical properties.

[0153] For example, the elastic modulus of the first plate 102 can be greater than or equal to 100 GPa, which helps to further enhance the mechanical strength of the middle plate and make the middle frame more reliable.

[0154] In some examples, the yield strength of the first plate 102 can be greater than or equal to the yield strength of the second plate 103 and the matrix 101. This ensures the rigidity and hardness of at least a portion of the middle plate formed by the first plate 102, and guarantees the mechanical properties of the middle frame.

[0155] In some examples, the micro Vickers hardness of the first plate 102 can be greater than or equal to the micro Vickers hardness of the second plate 103 and the matrix 101. This allows at least a portion of the middle plate formed from the first plate 102 to have high rigidity and hardness, achieving thinning of the middle plate while maintaining the mechanical properties of the middle frame.

[0156] For example, the material of the first plate 102 may include one or more of aluminum-based composite materials and magnesium-based composite materials. The middle plate formed by the first plate 102 can have higher hardness and rigidity, ensuring the high strength and high reliability of the middle frame.

[0157] In some examples, the material of the first plate 102 may also include reinforcing materials, which can further enhance the strength and rigidity of the middle plate, giving the middle frame higher mechanical properties.

[0158] For example, the reinforcing material may include ceramic particles, which have a significant reinforcing effect, enabling the molded middle plate and frame to have better mechanical strength at a lower cost. Of course, in some other examples, the reinforcing material may also be other types of materials, such as fiber materials, nanomaterials, metal powders, etc.

[0159] The material of the second plate 103 can be a material with good hardness and rigidity. In some examples, the material of the second plate 103 can be different from the material of the first plate 102 and the material of the substrate 101, or in some examples, the material of the second plate 103 can be the same as the material of the substrate 101.

[0160] Referring to Figure 4, the base 101 may include a first sub-part 1011 and a second sub-part 1012. The first sub-part 1011 may be a plate-like structure, and the second sub-part 1012 may be a ring-like structure. A portion of the second sub-part 1012 may surround the outside of the first sub-part 1011, and a portion of the second sub-part 1012 may protrude from one side of the first sub-part 1011.

[0161] The thickness direction of the base 101 can be aligned with the thickness direction of the middle frame 10, as shown in the z-direction of the figure. Along the thickness direction (z-direction), a portion of the second segment 1012 can protrude from one side of the first segment 1011, meaning the height of the second segment 1012 can be higher than the height of the first segment 1011. The second segment 1012 is arranged around the first segment 1011, and the second segment 1012 and the first segment 1011 can form a receiving groove 1011a, thus giving the base 101 a receiving groove 1011a on one side along the thickness direction (z-direction).

[0162] The bottom wall of the receiving groove 1011a can be formed by the first split part 1011, or it can be formed by the first split part 1011 and part of the second split part 1012, and the annular groove sidewall of the receiving groove 1011a is formed by the second split part 1012.

[0163] The shape of the receiving groove 1011a can match the shape of the first plate 102 and the second plate 103. For example, if the outer contour shape of the first plate 102 and the second plate 103 is a rectangle, the contour shape of the receiving groove 1011a can also be a rectangle.

[0164] In some examples, the base 101 may also include a third portion 1013, which is located on one side of the first portion 1011 and the second portion 1012. For example, the length direction of the base 101 may be consistent with the length direction of the middle frame 10, as shown in the y-direction in the figure. Along the length direction (y-direction), the third portion 1013 may be located on one side of the first portion 1011 and the second portion 1012.

[0165] The third part 1013 of the base 101 can be used to form a border, and the two border parts formed by the third part 1013 and the second part 1012 can together constitute the entire border. The third part 1013 can also be used to form a middle plate.

[0166] Alternatively, in some examples, the base 101 may also include a fourth sub-part 1014 located on one side of the first sub-part 1011 and the second sub-part 1012. For example, along the length direction (y direction), the fourth sub-part 1014 and the third sub-part 1013 may be located on opposite sides of the first sub-part 1011 and the second sub-part 1012, respectively.

[0167] The fourth part 1014 can be used to form the border, and the borders formed by the second part 1012, the third part 1013, and the fourth part 1014 can together constitute the entire border 12. The fourth part 1014 can also be used to form the middle plate.

[0168] Currently, in some examples, the base 101 may not include the third part 1013 and / or the fourth part 1014 mentioned above. For example, the base 101 may only include the first part 1011 and the second part 1012. The second part 1012 can be used to form the entire border of the middle frame, and the second plate 103 can be used to form the entire middle plate of the middle frame.

[0169] The base 101 can be a one-piece structural component. For example, a plate-shaped metal body can be used as the base material, and a receiving groove 1011a can be formed on one side of the metal body through CNC machining, die casting, or other methods to obtain the base 101, which has the aforementioned first split part 1011, second split part 1012, etc. The first split part 1011, second split part 1012, etc., can be made of the same material.

[0170] Step S102: Place the first plate in the receiving groove and stack the second plate on top of the first plate.

[0171] First, a first plate is placed in the receiving groove, and then a second plate is stacked on top of the first plate, on the side facing away from the bottom wall of the receiving groove (the first split part). For example, referring to the direction of the dashed arrow shown in FIG4, the first plate 102 is first placed in the receiving groove 1011a, so that one side of the first plate 102 can be in contact with the bottom wall of the receiving groove 1011a (such as the first split part 1011). Then, the second plate 103 is stacked on the first plate 102, and one side of the second plate 103 can be in contact with the side of the first plate 102 facing away from the first split part 1011.

[0172] The first plate 102 is placed in the receiving groove 1011a, and the second plate 103 is stacked on the first plate 102. At least there will be a gap between the outer side of the first plate 102 and the inner side of the second split part 1012. The gap can be an assembly gap, and the gap can also serve as a welding path for subsequent welding steps (such as step S103) to enable welding between at least the first plate 102 and the base 101.

[0173] In some examples, the second plate 103 (partially or entirely) may also be placed within the receiving groove 1011a, and the gap may also exist between the outer side of the second plate 103 and the inner side of the second split portion 1012. That is, the above-described step S102, which places the first plate in the receiving groove and superimposes the second plate on the first plate, may include step S102a: placing the second plate within the receiving groove, with a gap between the outer side of the first plate, the outer side of the second plate, and the inner side of the second split portion.

[0174] Figure 5 is a cross-sectional view of the assembly of the substrate, the first plate and the second plate in Figure 4, and Figure 6 is a structural diagram of the assembly of the substrate, the first plate and the second plate in Figure 4.

[0175] For example, as shown in Figure 5, when the first plate 102 and the second plate 103 are stacked sequentially in the receiving groove, the first segment 1011 of the substrate 101, the first plate 102, and the second plate 103 are stacked sequentially along the thickness direction (z direction), with the first plate 102 located between the first segment 1011 and the second plate 103. The second segment 1012 of the substrate 101 may surround the outside of the first plate 102 and the second plate 103.

[0176] The side of the second segment 1012 that forms the receiving groove 1011a is the inner side of the second segment 1012. The side of the first plate 102 that is adjacent to and opposite to the inner side of the second segment 1012 is the outer side of the first plate 102. The side of the second plate 103 that is adjacent to and opposite to the inner side of the second segment 1012 is the outer side of the second plate 103. There is a certain gap between the outer side of the first plate 102 and the inner side of the second segment 1012, and there is also a certain gap between the outer side of the second plate 103 and the inner side of the second segment 1012. This creates a gap 104 between the outer sides of the first plate 102 and the second plate 103 and the inner side of the second segment 1012. Referring to Figure 6, the overall outer contour shape of the gap 104 can be a ring-like shape. For example, if the outer contour shapes of the first plate 102, the second plate 103, etc., are rectangular, the outer contour shape of the gap 104 can be a rectangular ring.

[0177] Step S103: Weld along the seam to form a first weld zone between at least the first plate and the substrate.

[0178] For example, a welding device can be used to weld along the seam, so that at least the first plate and the substrate form a first welding zone, and at least the first plate and the substrate are connected by welding.

[0179] In an example where there is a gap between the first plate, the second plate, and the second sub-part, step S103 may include step S103a: welding the first plate, the second plate, and the substrate along the gap to form a first welding area between the first plate, the second plate, and the substrate. This connects the first plate, the second plate, and the substrate through welding.

[0180] Of course, in some other examples, the first plate is placed in the receiving groove of the substrate, and the second plate is stacked on top of the first plate. The gap may only exist between the outer surface of the first plate and the inner surface of the second segment. Specific implementation methods are described below. In the example where only the outer surface of the first plate and the inner surface of the second segment have a gap, after welding along the gap, the first plate and the substrate are welded together, and there is no connection between the second plate and the substrate, or between the second plate and the first plate.

[0181] The welding method is illustrated here by taking the example of gaps on the outer side of the first plate, the outer side of the second plate, and the inner side of the second part.

[0182] Figure 7 is a schematic diagram of the substrate, first plate, and second plate in Figure 6 before welding using the welding device. Figure 8 is a cross-sectional schematic diagram of the substrate, first plate, and second plate in Figure 6 during welding using the welding device. In Figure 8, the dashed line indicates the position where the stirring head 201 of the welding device 200 is inserted into the gap 104.

[0183] For example, friction stir welding (FSW) can be used to weld the first plate 102, the second plate 103, and the substrate 101. The welding apparatus 200 for performing friction stir welding may include a stirring head 201, as shown in Figure 7. The outer contour of the stirring head 201 can be a trapezoidal columnar shape, and the end of the stirring head 201 with a smaller size may have a stirring pin (not shown in the figure). The stirring head 201 can be inserted into the gap 104 through the stirring pin.

[0184] For example, a stirring needle can be inserted into a certain position in the gap 104, which can serve as the welding starting point. The stirring head 201 is rotated at high speed. The rotating stirring head 201 generates frictional heat through friction with the first plate 102, the second plate 103, and the second split portion 1012 of the base 101, softening the first plate 102, the second plate 103, and the second split portion 1012. Referring to Figure 8, under certain pressure conditions, the stirring head 201 can be inserted into the gap 104, allowing it to be inserted into and enveloped by the softened first plate 102, the second plate 103, and the second split portion 1012.

[0185] In some examples, the frictional heat generated by the high-speed rotation of the stirring head 201 can also soften the first segment 1011 of the substrate 101 to a certain extent. Under pressure, the stirring head 201 can also be inserted into the first segment 1011 of the substrate 101. That is, the stirring head 201 is inserted into the softened first plate 102, second plate 103, first segment 1011 and second segment 1012 through the gap 104, so that the stirring head 201 is wrapped by the softened first plate 102, second plate 103 and substrate 101.

[0186] The stirring head 201 continues to rotate at high speed and moves along the gap 104. The frictional heat generated between the stirring head 201 and the first plate 102, the second plate 103 and the substrate 101 softens the first plate 102, the second plate 103 and the substrate 101 and causes them to undergo plastic flow under the stirring action of the stirring head. The flowing first plate 102, the second plate 103 and the substrate 101 fuse together, and atomic-level bonding occurs between the materials to form an integral structure.

[0187] Figure 9 is a partial structural diagram of a substrate, a first plate, and a second plate after welding, according to an embodiment of this application. Figure 10 is a schematic diagram of the substrate, the first plate, and the second plate after welding in Figure 9.

[0188] Referring to Figure 9, a first welding area 1051 (the part enclosed by the dotted line in Figure 9) can be formed between the first plate 102, the second plate 103, and the substrate 101. Under the action of the stirring head, the materials of the first plate 102, the second plate 103, and the substrate 101 in the first welding area 1051 are mixed together to form an integral structure, connecting the first plate 102, the second plate 103, and the substrate 101 at the location of the first welding area 1051. The areas of the first plate 102, the second plate 103, and the substrate 101 outside the first welding area 1051 are not connected. For example, the first split parts 1011 of the first plate 102, the second plate 103, and the substrate 101 outside the first welding area 1051 are only stacked on top of each other and are not fixedly connected.

[0189] During the welding process, when welding is performed along the seam 104 using a welding device to form a first welding zone 1051 between the first plate 102, the second plate 103, and the substrate 101, the first plate 102 is located between the second plate 103 and the first segment 1011 of the substrate 101. The pressure applied by the welding device during welding is primarily directed onto the second plate 103 and the second segment 1012 of the substrate 101, which helps reduce deformation of the first plate 102 caused by pressure during welding. Furthermore, the second plate 103 can exert pressure on the first plate 102 during welding, further reducing the deformation of the first plate 102 caused by welding. This improves the flatness of the formed plate and the yield rate of the finished product.

[0190] The overall outer contour shape of the slit 104 can be roughly annular. A stirring needle is inserted into a certain position of the slit 104, and this position serves as the welding starting point. The substrate 101, the first plate 102, and the second plate 103 are welded along the slit 104. When the stirring needle moves back to the welding starting point position along the slit 104, the welding of the first plate 102, the second plate 103, and the substrate 101 is achieved, forming a first welding area 1051 between the first plate 102, the second plate 103, and the substrate 101. At least a portion of the contour shape of this first welding area 1051 can be consistent with the contour shape of the slit 104, as shown in Figure 10. After welding and cooling of the first plate 102, the second plate 103, and the substrate 101, at least a portion of the outer contour shape of the first welding area 1051 can be roughly annular.

[0191] It should be noted that the profile shape of the cross section of the first welding area 1051 (such as a cross section formed by a plane parallel to the thickness direction) can match the outer profile shape of the stirring head. For example, the shape of the stirring head can be a trapezoidal column, and the profile shape of the cross section of the first welding area 1051 can be similar to the cross section shape of a trapezoidal column.

[0192] In some examples, the welding start point can be used as the welding end point, such as using position D1 as the welding start point in Figure 10. Exemplarily, position D1 can also be used as the welding end point. That is, starting from position D1, the stirring needle moves along the gap 104, completes one circle of welding, and returns to position D1. Welding is then stopped, the stirring needle is withdrawn, and the resulting first weld area 1051 can be roughly annular.

[0193] It should be noted that after the stirring needle is pulled out, a hole structure will be formed in the first welding area 1051, resulting in a hole structure on the second sub-part 1012 of the base 101, which affects the shape of the second sub-part 1012. For example, when the second sub-part 1012 is subsequently formed into a frame through post-shaping processing (see below), the shape of the second sub-part 1012 at the hole structure can be fully taken into account, and the shape of the frame can be designed accordingly.

[0194] Alternatively, in some examples, the end point of the weld may not be on the gap 104, so that the outer contour of the first weld area 1051 is partially annular.

[0195] For example, after welding the substrate, the first plate, and the second plate along the seam in step S103a above, the method may further include:

[0196] Step S1031: Weld the end point structure within the third body section.

[0197] For example, taking position D1 as shown in Figure 10 as the welding starting point, the stirring head is inserted into position D1 of the gap 104, and when it moves along the gap 104 and returns to position D1, welding can be achieved between the first plate 102, the second plate 103, and the substrate 101. The stirring head can continue to move, such as moving into the third part 1013 of the substrate 101, and then the welding can be stopped and the stirring head pulled out, so that a hole structure 1051a is formed in the third part 1013. This hole structure 1051a can serve as the welding endpoint structure, serving as the end point of the welding.

[0198] Step S1032: Form a through hole at the location of the welding endpoint structure to remove the welding endpoint structure.

[0199] Step S1033: Form part of the middle plate and part of the frame of the third part.

[0200] The middle plate and part of the frame formed by the third segment 1013 can enclose the second receiving cavity 132 (see Figures 13 and 14), and the through hole 111 can be located within the second receiving cavity 132. The through hole 111 and the second receiving cavity 132 can be used to accommodate and assemble the aforementioned camera. This design rationally optimizes the structure of the frame 12, meeting the requirements for accommodating and assembling components such as the camera, while also preventing the welding endpoint structure from affecting the shape of the second segment 1012, thus reducing the difficulty of structural design and molding of the frame 12 and facilitating its implementation.

[0201] It should be noted that step S1031 can occur after step S103a and before step S104. Steps S1032 to S1033 can occur after step S103a, before steps S104 to S106, or after any of steps S104 to S106.

[0202] Alternatively, in some other examples, after welding the substrate, the first plate and the second plate along the seam in step S103a above, the method may further include: S1034: shaping the welding endpoint structure within the fourth sub-section.

[0203] Step S1035: Form a through hole at the location of the weld endpoint structure to remove the weld endpoint structure.

[0204] Step S1036: Form part of the middle plate and part of the frame of the fourth part.

[0205] Referring to Figure 10, after welding around the seam 104, the stirring needle can continue to move. If it moves to the fourth part 1014 of the base 101, the welding can be stopped, forming a hole structure in the fourth part 1014. This hole structure can be the welding endpoint structure, serving as the end point of the welding.

[0206] The middle plate and part of the frame formed by the fourth sub-part 1014 can enclose the aforementioned third receiving cavity 133 and fourth receiving cavity 134 (see Figures 13 and 14). The through hole can be located in the third receiving cavity 133 or the fourth receiving cavity 134, for example, the through hole can be used to accommodate a speaker or microphone. It can also avoid the welding endpoint structure from affecting the shape of the second sub-part 1012, etc., which helps to reduce the difficulty of frame structure design and molding construction, and is easy to implement.

[0207] Step S104: Remove the second board material as a whole.

[0208] In an example where there is a gap between the first plate, the second plate, and the second sub-part, as described above, the first plate 102, the second plate 103, and the substrate 101 are connected together at the first welding area 1051. The first plate 102, the second plate 103, and the first sub-part 1011 of the substrate 101 are merely stacked on top of each other outside the first welding area 1051, and are not fixedly connected.

[0209] Step S104 may include step S104a: removing the portion of the structure connected to the second plate in the first welding zone to disconnect the second plate and the substrate.

[0210] By removing the portion of the structure connected to the second plate 103 within the entire first welding area 1051 (see Figure 9), the second plate 103 can be disconnected from the substrate 101 (and the remaining portion of the first welding area). In areas other than the first welding area 1051, there is no connection between the second plate 103 and the substrate 101 or the first plate 102; therefore, the second plate 103 can be directly removed, separating it entirely from the first plate 102 and the substrate 101.

[0211] This method removes only the portion of the structure within the first welding area 1051 that connects to the second plate 103, severing the second plate 103 from the substrate 101. This allows for the complete removal of the second plate 103 without the need for cutting the entire area. The small cutting area, coupled with the fact that the pressure during cutting primarily acts on the edge of the second plate 103 where it meets the first welding area 1051, reduces or eliminates the impact of the cutting pressure on the first plate 102, thus minimizing or preventing deformation of the first plate 102.

[0212] For example, the portion of the structure connected to the second plate 103 in the first welding area 1051 can be removed by machining, for example, by using CNC cutting process to remove the portion of the structure connected to the second plate 103 in the first welding area 1051.

[0213] Figure 11 is a cross-sectional view of the substrate, the first plate, and the second plate after welding in Figure 10.

[0214] For example, referring to Figure 11, the cutting and removal area is indicated by region S1 shown in Figure 11. If a CNC cutting device is used, the cutting and removal area S1 is moved along the first welding area 1051 to remove the part of the structure connected to the second plate 103 in the entire first welding area 1051, so that the second plate 103 can be disconnected from the base 101 and removed.

[0215] In some examples, when removing the portion of the structure connected to the second plate 103 within the first welding area 1051, only the portion of the structure connected to the second plate 103 within the first welding area 1051 can be removed, based on the outline shape of the first welding area 1051.

[0216] Alternatively, in some examples, while removing the portion of the structure connected to the second plate 103 within the first welding area 1051, a portion of the second plate 103 can also be removed. For example, when CNC cutting is performed in the cutting removal area shown in Figure 11 to disconnect the second plate 103 from the base 101, the portion of the structure connected to the second plate 103 within the first welding area 1051 is removed, along with the portion of the second plate 103 connected to the first welding area 1051. This reduces the precision requirements of the cutting process, allowing for the disconnection of the second plate 103 from the base 101 with fewer cutting steps, making it easier to implement.

[0217] In the example where only the outer surface of the first plate and the inner surface of the second part have a gap, after welding along the gap, there is no connection between the second plate and the substrate or the first plate. The second plate can be removed directly without affecting the first plate, and the deformation of the first plate can be reduced or avoided.

[0218] Step S105: Remove the portion of the structure located between the first part and the second part on the substrate to disconnect the first part and the second part, and remove the first part.

[0219] The second segment 1012 of the base 101 surrounds the outside of the first segment 1011, removing part of the structure on the base 101 located between the first segment 1011 and the second segment 1012, thus breaking the connection between the first segment 1011 and the second segment 1012. There is no connection between the first segment 1011 and the first plate 102, so the first segment 1011 can be directly removed from the base 101, and the first segment 1011 as a whole is separated from the first plate 102 and the second segment 1012.

[0220] This method removes only the connecting structure between the first segment 1011 and the second segment 1012 on the substrate 101, disconnecting the first segment 1011 and the second segment 1012, thus allowing the entire first segment 1011 to be removed. It eliminates the need to cut away the entire area of ​​the first segment 1011, resulting in a smaller cutting area. Furthermore, the pressure during cutting is primarily applied to the edge of the first segment 1011 where it meets the second segment 1012, further reducing or eliminating the impact of cutting pressure on the first sheet material 102 and minimizing deformation of the first sheet material 102.

[0221] For example, a portion of the structure between the first split portion 1011 and the second split portion 1012 can be removed by machining. For instance, a CNC cutting process can be used to remove the portion of the structure on the base 101 located between the first split portion 1011 and the second split portion 1012.

[0222] For example, referring to Figure 11, the cutting and removal area is indicated by region S2 shown in Figure 11. If a CNC cutting device is used, the cutting and removal area is moved along the surrounding direction of the second split part 1012 to remove the structure between the surrounding second split part 1012 and the first split part 1011, so that the first split part 1011 can be disconnected from the second split part 1012 and removed.

[0223] The structure located between the first split portion 1011 and the second split portion 1012 may include a portion of the first split portion 1011 and a portion of the second split portion 1012. That is, during the cutting and removal process, the portion of the first split portion 1011 connected to the second split portion 1012 and the portion of the second split portion 1012 connected to the first split portion 1011 may be removed, thereby disconnecting the first split portion 1011 and the second split portion 1012.

[0224] Alternatively, the structure may consist of only the first split portion 1011, meaning that during the cutting and removal process described above, the portion of the first split portion 1011 that is connected to the second split portion 1012 may be removed, thereby disconnecting the first split portion 1011 and the second split portion 1012.

[0225] Alternatively, the structure may consist only of the second split portion 1012, meaning that during the cutting and removal process described above, the portion of the second split portion 1012 that is connected to the first split portion 1011 may be removed, thereby disconnecting the first split portion 1011 and the second split portion 1012.

[0226] Alternatively, the partial structure may include at least a portion of the first split portion 1011 and / or at least a portion of the second split portion 1012, and may also include at least a portion of the first welding area 1051.

[0227] Figure 12 is a cross-sectional view of the welded structure of the substrate 101, the first plate 102, and the second plate 103 in Figure 11 after the cutting process.

[0228] For example, in an example where there is a gap between the first plate, the second plate, and the second split portion, after cutting according to the removal areas S1 and S2 shown in FIG. 11, the second plate 103 and the first split portion 1011 are removed. Referring to FIG. 12, the remaining base 101 has the second split portion 1012 and the first plate 102. The second split portion 1012 is arranged around the first plate 102, and in the thickness direction (z direction), both sides of the second split portion 1012 can protrude from the first plate 102. That is, there is a height difference between the two opposite sides of the second split portion 1012 and the first plate 102 in the thickness direction. The first plate 102 and the second split portion 1012 are connected to form an integral structure.

[0229] Along the thickness direction (z-direction), the first plate 102 may include two opposing sides, and the second split portion 1012 and one side of the first plate 102 may form a first receiving cavity 131. The second split portion 1012 and the other side of the first plate 102 may form a cavity 14.

[0230] Step S106: Form at least a portion of the middle plate from the first sheet material and at least a portion of the frame from the second split part to form an integral middle frame.

[0231] The retained first sheet 102 is used to form the middle sheet 11, and the thickness of the first sheet 102 is approximately the thickness of at least a portion of the middle sheet 11. Exemplarily, the first sheet 102 may be post-shaped to form at least a portion of the middle sheet 11.

[0232] For example, during the cutting and removal process described above, burrs or other structures may be formed on the first plate 102. The first plate 102 can be deburred or shaped, and the processed first plate 102 can form at least a portion of the middle plate 11.

[0233] The second portion 1012 of the retained base 101 is used to form the border 12. For example, the second portion 1012 can be post-shaped to form at least a portion of the border 12.

[0234] For example, the shape and size of the second part 1012 can be processed, such as constructing the arc-shaped outer surface required to form the frame 12, achieving the required thickness and shape of the frame 12, and forming the required interface, pickup port, and sound outlet on the frame 12. The processed second part 1012 can form at least a part of the frame 12.

[0235] It is understandable that after at least the first plate is welded to the substrate to form the first welding area 1051, after cutting and post-shaping processes, a portion of the first welding area 1051 will be removed, so that only a portion of the first welding area 1051 remains between at least a portion of the middle plate and at least a portion of the frame after forming.

[0236] Figure 13 is a cross-sectional schematic diagram of the middle frame obtained after the substrate and the first plate in Figure 12 have undergone shaping and other treatments.

[0237] The portion retained in the first welding area is designated as the second welding area, as shown in Figure 13. A second welding area 1052 exists between at least a portion of the frame 12 and at least a portion of the middle plate 11. Within the second welding area 1052, the materials of the second plate 103 and the substrate 101 are mixed together to form an integral structure, connecting at least a portion of the frame 12 and at least a portion of the middle plate 11 to form an integral middle frame 10. At least a portion of the frame 12 surrounds at least a portion of the middle plate 11, and the at least a portion of the frame 12 and at least a portion of the middle plate 11 can form a first receiving cavity 131 and a cavity 14. For example, the first receiving cavity 131 can be used to accommodate assembled batteries.

[0238] Through steps S101 to S106, at least a portion of the frame 12 and at least a portion of the middle plate 11 are formed using the substrate 101 and the first plate 102, respectively, thereby forming an integral middle frame 10. During the welding process, the second plate 103 can exert a certain pressure on the first plate 102, which helps to reduce the deformation effect of welding on the first plate 102. In the example where there is a gap 104 between the first plate 102, the second plate 103 and the substrate 101, the first plate 102 is located between the second plate 103 and the first split portion 1011 of the substrate 101. The pressure during the welding process is mostly applied directly to the second plate 103 and the second split portion 1012 of the substrate 101, which can reduce the deformation effect on the first plate 102.

[0239] During the process of removing the second plate 103 and the first split portion 1011 to retain the first plate 102 and the second split portion 1012 (as described in steps S104 to S105 above), only the portion of the structure connected to the second plate 103 within the first welding area 1051 is removed, thus disconnecting the second plate 103 from the base 101 (or the second plate is removed directly without cutting). By removing only the portion of the structure connecting the first split portion 1011 and the second split portion 1012 on the base 101, thus disconnecting the first split portion 1011 from the second split portion 1012, the second plate 103 and the first split portion 1011 can be separated from the first plate 102 (and the second split portion 1012 of the base 101) respectively, retaining the first plate 102 and the second split portion 1012 to form at least a portion of the middle plate 11 and at least a portion of the frame 12, respectively, forming the first receiving cavity 131. There is no need to cut and remove the entire area of ​​the second plate 103 and the first split part 1011. The cutting area is small, and the pressure during the cutting process mainly acts on the position where the edge of the second plate 103 meets the first welding area 1051 and the position where the edge of the first split part 1011 meets the second split part 1012. This can reduce or avoid the impact of the pressure during the cutting process on the second plate 103 and reduce or avoid the deformation problem of the first plate 102.

[0240] This makes the first plate 102 an ultra-thin plate, and at least part of the resulting middle plate can also have high flatness and high finished product yield. Thus, while ensuring high finished product yield, the thickness of the middle plate can be further reduced to obtain an ultra-thin middle frame, which is conducive to increasing the thickness space of the receiving cavity (such as the first receiving cavity) and realizing the thinning design of electronic devices.

[0241] For example, through steps S101 to S106 above, the thickness of at least a portion of the middle plate can be less than or equal to 0.3 mm. This effectively reduces the thickness of at least a portion of the middle plate, which is beneficial for increasing the space of the first receiving cavity in the thickness direction and for meeting the thinning design requirements of electronic devices.

[0242] For example, the thickness of at least part of the middle plate can also be less than or equal to 0.2 mm, making at least part of the middle plate thinner, further increasing the space of the first receiving cavity, and making it easier to achieve the thinning design of the electronic device.

[0243] For example, the thickness of at least part of the middle plate can be less than or equal to 0.15 mm, which realizes the ultra-thin design of at least part of the middle plate, allowing the first receiving cavity to have a larger space, and also realizing the ultra-thin design of electronic devices.

[0244] Figure 13 shows an example of obtaining a portion of the frame 12 and a portion of the middle plate 11 after the above steps S101 to S106. The portion of the frame 12 is arranged around the portion of the middle plate 11, so that the portion of the frame 12 and the portion of the middle plate 11 can form a first receiving cavity 131.

[0245] In an example where the base 101 includes a first sub-part 1011, a second sub-part 1012, a third sub-part 1013, and a fourth sub-part 1014 (as shown in FIG4), after the base is provided in step S101, the method may further include forming a border 12 and a middle plate 11 of the third sub-part.

[0246] Figure 14 is a structural schematic diagram of the middle frame in Figure 13.

[0247] As shown in Figure 14, the partial frame 12 and partial middle plate 11 formed by the third segment can enclose a second receiving cavity 132. For example, the second receiving cavity 132 can be used to accommodate a camera.

[0248] For example, a second receiving cavity 132 can be formed on the third part by machining methods such as CNC, so that the third part can form part of the frame 12 and part of the middle plate 11.

[0249] After providing the substrate in step S101, the method may further include forming a partial frame 12 and a partial middle plate 11 for the fourth segment. As shown in FIG14, the partial frame 12 and the partial middle plate 11 formed by the fourth segment can enclose a third receiving cavity 133 and a fourth receiving cavity 134. For example, the third receiving cavity 133 and the fourth receiving cavity 134 can be used to accommodate a microphone, a speaker, etc., respectively.

[0250] For example, a third receiving cavity 133 and a fourth receiving cavity 134 can be formed on the third segment by machining methods such as CNC, so that the third segment can form part of the frame 12 and part of the middle plate 11.

[0251] This results in the middle frame 10, as shown in Figure 14, where the side frame 12 and the middle plate 11 together form the first receiving cavity 131, the second receiving cavity 132, the third receiving cavity 133, and the fourth receiving cavity 134.

[0252] It should be noted that the first receiving cavity 131 can be used to accommodate the battery, that is, the first receiving cavity 131 can be part of the battery compartment of the electronic device. For example, part or all of the second receiving cavity 132 formed on the third split part 1013 can be used together with the first receiving cavity 131 as the battery compartment of the electronic device to accommodate the entire battery.

[0253] Alternatively, the first receiving cavity 131 can be used to accommodate the entire battery, that is, the first receiving cavity 131 can be the entire battery compartment, and the entire battery can be accommodated in the first receiving cavity 131.

[0254] Of course, in some other examples, the entire frame 12 and the middle plate 11 can be obtained through steps S101 to S106 described above. For example, as mentioned above, the base 101 may only include a first segment 1011 and a second segment 1012. A portion of the second segment 1012 can form the entire frame 12, meaning the entire frame 12 can be formed using the second segment 1012. At least a portion of the first plate 102 can form the entire middle plate 11, meaning the entire middle plate 11 can be formed using the first plate 102. The first receiving cavity 131 formed by the frame 12 and the middle plate 11 can be used to accommodate various components of electronic devices such as batteries and cameras, as described above.

[0255] Understandably, in the example of a foldable electronic device, the electronic device may include at least two mid-frames and a pivot structure. Two adjacent mid-frames can be rotatably engaged through a pivot structure, allowing the two mid-frames to rotate relative to each other, thereby enabling the opening and closing of the electronic device.

[0256] One of the mid-frames can be the mid-frame 10 that enables at least part of the mid-plate ultra-thin design, or multiple or all of the mid-frames can be the mid-frame 10 that enables at least part of the mid-plate ultra-thin design.

[0257] Figure 14a is a schematic diagram of the structure of another substrate, first plate, and second plate before assembly, provided in an embodiment of this application.

[0258] In an example where only the outer surface of the first plate 102 and the inner surface of the second split portion 1012 have a gap, as shown in FIG14a, after the first plate 102 is placed in the receiving groove (not shown) of the base 101 and the second plate 103 is stacked on top of the first plate 102, a gap 106 is formed between the outer surface of the first plate 102 and the inner surface of the second split portion 1012. There is no gap 106 between the second plate 103 and the second split portion 1012 for use as a welding path in subsequent welding steps.

[0259] The second plate 103 can at least partially accommodate the groove, or, in some examples, the first plate 102 can fill the entire space of the accommodating groove in the thickness direction, and the second plate 103 is superimposed on the first plate 102 on the side of the groove bottom wall (first split part) away from the accommodating groove, so that the second plate 103 is located outside the accommodating groove.

[0260] The above step S102, which involves superimposing the second plate onto the first plate, may include step S102b: making the second plate cover a portion of the first plate so that at least part of the gap between the first plate and the substrate is exposed.

[0261] As shown in Figure 14a, after the second plate 103 is superimposed on the first plate 102, the second plate 103 only covers a portion of the first plate 102. For example, along the thickness direction (e.g., the z-direction), the vertical projection of the second plate 103 onto the first plate 102 only overlaps with a portion of the first plate 102. This allows at least a portion of the gap 106 between the first plate 102 and the substrate 101 to be exposed, thereby enabling welding.

[0262] After step S102, in which the second plate is superimposed on the first plate, and before step S103, in which the weld is performed along the seam, the method may further include step S102c: pressing the first plate against the second plate.

[0263] For example, a clamp, a pressure device, or the like can be used to act on the second plate 103 and / or the substrate 101, so that the second plate 103 can squeeze the first plate 102, ensuring the pressure effect of the second plate 103 on the first plate 102 during the welding process, facilitating welding, reducing the deformation of the first plate 102 during the welding process, and improving the flatness of the middle plate and the yield of the finished product after forming.

[0264] The above step S103, welding along the seam to form a first welding area between at least the first plate and the substrate, may include step S103b: welding the first plate and the substrate along the seam to form a first welding area between the first plate and the substrate.

[0265] Figure 14b is a cross-sectional view of the substrate and the first plate in Figure 14a being welded using a welding device. The dashed line in Figure 14b indicates the position where the stirring head 201 of the welding device 200 is inserted into the gap 106.

[0266] Referring to Figure 14b, the first plate 102 and the substrate 101 can be welded together along the gap 106 using the welding device 200, thereby achieving a welded connection between the first plate 102 and the substrate 101.

[0267] For example, friction stir welding can be used to weld the first plate 102 and the substrate 101. The stirring needle of the welding device 200 is inserted into a certain position in the exposed gap 106, which serves as the welding starting point. The stirring head 201 rotates at high speed, softening the first plate 102 and the second segment 1012 of the substrate 101. As shown in Figure 14b, under certain pressure conditions, the stirring head 201 can be inserted into the gap 106, allowing it to penetrate the softened first plate 102 and the second segment 1012, and be encased by them.

[0268] In some examples, the frictional heat generated by the high-speed rotation of the stirring head 201 can also soften the first part 1011 of the substrate 101 to a certain extent. Under pressure conditions, the stirring head 201 can also be inserted into the first part 1011 of the substrate 101.

[0269] The stirring head 201 continues to rotate at high speed and moves along the gap 106. The frictional heat generated between the stirring head 201 and the first plate 102 and the substrate 101 softens the first plate 102 and the substrate 101, causing them to undergo plastic flow under the stirring action of the rotating head 201. The flowing first plate 102 and the substrate 101 fuse together, and atomic-level bonding occurs between the materials to form an integral structure. During the welding process, the second plate 103 does not weld to the substrate 101 or the first plate 102.

[0270] Figure 14c is a partial structural diagram of another substrate, first plate and second plate after welding provided in an embodiment of this application.

[0271] Referring to Figure 14c, a first welding area 1054 (the part enclosed by the dotted line in Figure 14c) can be formed between the first plate 102 and the substrate 101. Under the action of the stirring head, the materials of the first plate 102 and the substrate 101 in the first welding area 1054 are mixed together to form an integral structure, so that the first plate 102 and the substrate 101 are connected together at the position of the first welding area 1054. The areas of the first plate 102 and the substrate 101 outside the first welding area 1054 are not connected. For example, the first split parts 1011 of the first plate 102 and the substrate 101 outside the first welding area 1054 are only stacked on each other and there is no fixed connection between them.

[0272] There is no connection between the second plate 103 and the first plate 102 and the substrate 101. The second plate 103 can be assembled with the first plate 102 and the substrate 101 by means of the aforementioned clamps, pressure devices, etc., to compress the first plate 102. After removing the clamps or pressure devices, the second plate 103 can be directly removed and separated from the first plate 102.

[0273] In this method, the stirring head is inserted into the gap 106 between the first plate 102 and the base 101 to achieve the welding connection between the first plate 102 and the base 101. Compared with the above method of inserting the stirring head into the gap between the first plate 102, the second plate 103 and the base 101 to achieve welding, the size of the stirring head can be relatively small, the first welding area 1054 formed can be relatively small, and the deformation of the first plate 102 and the base 101 will also be smaller, which is conducive to making the formed middle plate have higher flatness and finished product yield.

[0274] It should be noted that after the second plate 103 is superimposed on the first plate 102, and the second plate 103 is assembled with the first plate 102 and the substrate 101 using clamps, pressure devices, etc., in some examples, the second plate 103 may be located within the movement trajectory area of ​​the stirring head along the gap 106. This will affect the partial movement of the stirring head along the gap 106, causing the stirring head 201 to only move along a portion of the gap 106 without moving the second plate 103, and the stirring head 201 cannot continue to move along another portion of the gap 106.

[0275] For example, the second plate 103 can cover another part of the gap 106, that is, in the thickness direction (such as the z-direction), the vertical projection of the second plate 103 overlaps with another part of the gap 106. Alternatively, the gap 106 can be completely exposed, that is, in the thickness direction (such as the z-direction), the vertical projection of the second plate 103 does not overlap with the gap 106, but the distance between another part of the second plate 103 and the gap 106 is small.

[0276] When welding the first plate 102 and the substrate 101 along the gap 106, the stirring head can be moved along a portion of the gap 106 (the part that is not covered or has a large distance from the second plate 103) to form a partial first welding area 1054 between the portion of the first plate 102 and the portion of the substrate 101. Then, the clamps, pressure devices, etc. are removed, and the second plate 103 is moved to expose the other part of the gap 106 or increase the distance between the other part of the gap 106 and the second plate 103, so that the stirring head can move along the other part of the gap 106, thereby forming a complete first welding area 1054 between the first plate 102 and the substrate 101.

[0277] The outer contour shape and cross-sectional contour shape of the gap 106 and the first welding area 1054 can be the same as the outer contour shape and cross-sectional contour shape of the gap 104 and the first welding area 1051 mentioned above.

[0278] In the above welding process, the welding start point on the gap 106 can be used as the welding end point, so that the overall outline of the first welding area 1054 can be a ring-like shape. Alternatively, the welding end point may not be on the gap 104. For example, the welding end point may be located in the third (or fourth) part of the base 101, so that the outer outline of the first welding area 1054 is a ring-like shape. For specific welding implementation methods, please refer to the above text, which will not be repeated here.

[0279] Figure 14d is a cross-sectional view of the first plate and the substrate in Figure 14c after welding, and the second plate is removed.

[0280] After welding the first plate and the substrate along the seam in step S103b above, forming a first welding zone between the first plate and the substrate, as shown in Figures 14c and 14d, the second plate 103 can be directly removed, thus achieving step S104 above. Referring to Figure 14d, after directly removing the second plate, the remaining first plate 102 and substrate 101 are connected together at the first welding zone 1054.

[0281] Continue with step S105 above to remove the part of the structure located between the first part and the second part on the substrate, so as to disconnect the first part and the second part and remove the first part.

[0282] The specific implementation of step S105 can be found above and will not be repeated here. For example, referring to Figure 14d, the cutting and removal area is indicated by region S2 shown in Figure 14d. If a CNC cutting device is used, the cutting and removal area is moved along the surrounding direction of the second split part 1012 to remove the structure between the surrounding second split part 1012 and the first split part 1011, so that the first split part 1011 can be disconnected from the second split part 1012 and removed.

[0283] Continue with step S106 to form at least a portion of the middle plate from the first plate and at least a portion of the frame from the second split portion, thereby forming the middle frame.

[0284] After cutting and post-shaping processes, the first sheet metal is formed into at least a middle plate, and the second split part is formed into at least a frame, thus obtaining the middle frame shown in FIG13. The portion of the first welding area 1056 (not shown in FIG13) remaining after cutting and post-shaping processes is designated as the second welding area 1052. The second welding area 1052 is formed between the at least part of the frame 12 and the at least part of the middle plate 11, so that the at least part of the frame 12 and the at least part of the middle plate 11 are connected to form an integral middle frame 10. The at least part of the frame 12 and the at least part of the middle plate 11 can form a first receiving cavity 131 and a cavity 14.

[0285] The specific implementation of step S106 can be found above, and will not be repeated here.

[0286] In an example where only the outer side of the first plate 102 and the inner side of the second split part 1012 have a gap, the above steps are used to obtain the middle frame.

[0287] During the welding process, the second plate 103 presses against the first plate 102 to achieve a pressure effect, which can reduce the deformation of the first plate 102 during welding. In the removal of the second plate 103 and the first split part 1011, the second plate 103 can be removed directly without cutting or other processes, and there is no need to cut the entire area of ​​the second plate 103 and the first split part 1011. This effectively reduces or avoids the impact of pressure during cutting on the second plate 103 and reduces or avoids deformation of the first plate 102. While ensuring a high yield rate, the thickness of the middle plate can be further reduced, resulting in an ultra-thin middle frame, which is beneficial for increasing the thickness space of the accommodating cavity (such as the first accommodating cavity) and realizing the thinner design of electronic devices.

[0288] Furthermore, there is no connection between the second plate 103 and the first plate 102 and the substrate 101. The second plate 103 is not welded. It is assembled together only by clamps, pressure devices, etc. The second plate 103 can be directly removed by removing the clamps, pressure devices, etc., without affecting the second plate 103. The second plate 103 can be reused, which helps to reduce processing costs.

[0289] The following example illustrates the middle frame forming method using a gap 104 between the first plate 102, the second plate 103, and the substrate 101 as an example. The following content can also be applied to examples where there is only a gap 106 between the first plate 102 and the substrate 101.

[0290] Figure 14e is a schematic diagram of an assembly of a substrate, a first plate, a second plate, and an outer frame provided in an embodiment of this application.

[0291] In some examples, after providing the substrate in step S101 above, the method may further include: setting an outer frame outside the substrate.

[0292] Referring to Figure 14e, the outer frame 107 can be a ring-shaped structural component. The outer frame 107 can be arranged around the outside of the base 101, and the outline shape of the outer frame 107 can match the outer outline shape of the base 101. The outer frame 107 can be arranged around the outside of the base 101 by means of interference fit, integral injection molding, etc.

[0293] After the middle frame is formed through the above steps S101 to S106, the middle frame may include at least a portion of the outer frame 107, which may be disposed around the outside of the edge. The outer frame 107 can improve the strength of the base 101 and enhance the strength of the formed middle frame. The outer frame 107 can also be used to achieve special appearance designs.

[0294] For example, the material of the outer frame 107 may be different from the material of the base 101. For example, the material of the outer frame 107 may include, but is not limited to, titanium alloy, stainless steel, etc.

[0295] In the above step S103, welding along the seam, friction stir welding can be used to weld the first plate (and the second plate) and the substrate. During the friction stir welding process along the seam, the side where the first plate is located is the advancing side of the friction stir welding process, and the side where the second part is located is the retreating side of the friction stir welding process.

[0296] Figure 15 is a schematic diagram of the structure when the welding device is used to weld the substrate, the first plate and the second plate in Figure 8.

[0297] The forward side can refer to the side where the direction of rotation of the stirring head is the same as the direction of movement of the stirring head along the gap, and the backward side can refer to the side where the direction of rotation of the stirring head is opposite to the direction of movement of the stirring head along the gap.

[0298] Referring to Figure 15, taking the rotation of the stirring head (not shown in the figure) in a counterclockwise direction (as indicated by the arc arrow in the figure) as an example, the stirring head (welding device 200) can move along the gap 104 in the direction of the straight arrow shown in the figure to perform welding. On the side where the first plate (and the second plate 103) is located, the rotational tangent direction of the stirring head (welding device 200) is consistent with the moving direction of the stirring head (welding device 200), and the side where the first plate is located is the advancing side in the friction stir welding process. The side where the second split part 1012 is located is the retreating side in the friction stir welding process.

[0299] It should be noted that the stirring head rotates and moves along the gap 104. The material on the advancing side is propelled by the stirring head, resulting in greater fluidity, which is beneficial for improving welding quality. By making the side containing the first plate the advancing side and the side containing the second sub-section 1012 the retreating side, the welding quality between the first plate and the base 101 is improved. This also reduces the degree of deformation of the first plate (near the first welding area) caused by welding, which is beneficial for improving the flatness of the intermediate plate formed by the first plate and thus improving the yield of finished products.

[0300] In some examples, to further improve the flatness of the middle plate and ensure the yield of finished products, a first groove can be formed at the junction of the first and second parts.

[0301] Figure 16 is a partial flowchart of a method for forming a middle frame according to an embodiment of this application.

[0302] For example, see Figure 16. Figure 16(a) shows a partial structural schematic after step S102 above, in which the first plate 102 is placed in the receiving groove and the second plate 103 is superimposed on the first plate 102.

[0303] The second part 1012 may surround the outside of the first part 1011, and the second part 1012 may protrude from the first part 1011, that is, along the thickness direction (such as the z direction), the height of the second part 1012 is higher than the height of the first part 1011.

[0304] For example, the second split portion 1012 may include a first portion 1112 and a second portion 1212, wherein the first portion 1112 may be located on one side of the second portion 1212 along the thickness direction (e.g., the z-direction), and the second portion 1212 may surround the outside of the first split portion 1011. That is, the second portion 1212 may be a part of the second split portion 1012 that surrounds the outside of the first split portion 1011, and the first portion 1112 may be a part of the second split portion 1012 that protrudes (exceeds) the second portion 1212 and the first split portion 1011 along the thickness direction (z-direction).

[0305] The first part 1112, the second part 1212, and the first split part 1011 together form a receiving groove. The first part 1112 can form the side wall of the receiving groove 1011a, and the first split part 1011 can form the bottom wall of the receiving groove, or the first split part 1011 and part of the second part 1212 can together form the bottom wall of the receiving groove.

[0306] Referring to Figure 16(a), after the first plate 102 and the second plate 103 are stacked in the receiving groove, the first part 1112 can surround the outside of the first plate 102 and the second plate 103, and the second part 1212 can surround the outside of the first split part 1011. A gap 104 can be formed between the first plate 102, the second plate 103 and the first part 1112.

[0307] After providing the substrate in step S101 and before placing the first plate in the receiving groove of the substrate in step S102, the method may further include forming a first groove at the edge where the first split portion and the second split portion meet. For example, in some examples, as shown in FIG16(a), a first groove 1111 is formed at the position where the first split portion 1011 meets the second portion 1212 (i.e., the second split portion).

[0308] The first groove 1111 is a blind groove on the inner side (the side forming the receiving groove) of the first segment 1011. The first groove 1111 is present at the edge where the first segment 1011 meets the annular second segment 1012 (second part 1212), making the overall outer contour of the first groove 1111 an annular groove, and the first groove 1111 surrounds the inner side of the second segment 1012. The cross-sectional shape of the first groove 1111 (e.g., a cross-section made along a plane parallel to the thickness direction) can be a regular shape such as rectangle or arc, or it can be an irregular shape.

[0309] It should be noted that after welding along the seam in step S103 above, as shown in Figure 16(b), the first plate 102, the second plate 103, and the first part 1112 can be connected at the position of the first welding area 1051. In some examples, the first part 1112 may have the first welding area 1051, and the second part 1112 may also have the first welding area 1051. The first split part 1011 may not have the first welding area 1051, such as when the stirring head is inserted into the seam 104 and into the second split part 1012, but not into the first split part 1011. The first groove 1111 can be located on one side of the first welding area 1051, and there can be a certain distance between the first groove 1111 and the first welding area 1051.

[0310] Alternatively, in some examples, the first welding area 1051 may be present on both the first portion 1112 and the second portion 1212 of the second split portion 1012, and the first welding area 1051 may also be present on the first split portion 1011, such as within the stirring head insertion gap 104, the second split portion 1012, and the first split portion 1011. Similarly, the first groove 1111 may be located on one side of the first welding area 1051, and a certain distance may be maintained between the first groove 1111 and the first welding area 1051.

[0311] The removal of the portion of the structure located between the first and second parts of the substrate in step S105 may include: removing the portion of the structure located on the side of the first groove away from the first plate material on the first part.

[0312] For example, referring to Figure 16, Figure (b) shows a partial structural diagram after step S103 above, where the first plate 102, the second plate 103, and the base 101 are welded along the gap 104. By moving the cutting along the circumferential direction of the second split portion 1012 in the removal area S2 shown in the figure, the portion of the structure on the side of the first split portion 1011 located in the first groove 1111 opposite to the first plate 102 can be removed, thus separating the first split portion 1011 from the second split portion 1012.

[0313] A first groove 1111 is formed on the first split portion 1011, and a portion of the structure on the side of the first split portion 1011 opposite to the first plate 102 is removed by cutting, thereby separating the first split portion 1011 from the second split portion 1012. During the cutting process, the first plate 102 is not cut, and burrs or other structures are not formed at the junction of the first plate 102 and the second split portion 1012 (first welding area 1051). This simplifies the post-forming process of the first plate 102 and reduces or avoids deformation problems caused to the first plate 102 during post-forming. Furthermore, it further reduces the deformation of the first plate 102 during cutting, which helps improve the flatness of the formed plate and increases the yield of the finished product.

[0314] Figure 16(c) shows a partial structural diagram of the middle frame 10 formed after the first plate 102 forms at least a part of the middle plate 11 and the second split part 1012 forms at least a part of the frame 12 in the above step S106.

[0315] As shown in Figures 16(b) and 16(c), after welding, CNC cutting, and post-shaping, the first part 1112 of the second split part 1012 can form the first frame 121 of the frame 12, and the second part 1212 of the second split part 1012 can form the second frame 122 of the frame 12. The first frame 121 and the second frame 122 can be located on opposite sides of the middle plate 11 along the thickness direction (z direction) and protrude from the middle plate 11 respectively. That is, along the thickness direction, the first frame 121 and the middle plate 11 have a height difference, and the second frame 122 and the middle plate 11 have a height difference.

[0316] Referring to Figure 16(c), taking the part enclosed by the dotted line in the figure as the second welding area 1052 as an example, at least a part of the middle plate 11 and at least a part of the frame 12 have a second welding area 1052, so that at least a part of the middle plate 11 and at least a part of the frame 12 are connected at the position of the second welding area 1052 to form an integral middle frame 10.

[0317] In some examples, the first frame 121 of the border 12 may have a second welding area 1052, and the second frame 122 of the border 12 may have a second welding area 1052. The element composition of the first frame 121 located within the second welding area 1052 may be different from the element composition of the second frame 122 located within the second welding area 1052.

[0318] In an example where there is a gap between the first plate, the second plate, and the substrate, during the welding process along the gap in step S103, the stirring head rotates to achieve welding, and the materials of the first plate, the second plate, and the substrate are mixed together under the action of the stirring head. For example, in an example where the stirring head is inserted into the second part but not into the first part, as shown in Figure 16(b), the first part 1112 and the second part 1212 have a first welding area 1051, while the first part 1011 does not have a first welding area 1051. Under the action of the stirring head, the materials of the first plate 102, the second plate 103, and the first part 1112 are mixed together. The material of the first part 1112 located within the first welding area 1051 is a mixture of the materials of the first plate 102, the second plate 103, and the first part 1112. The material of the second part 1212 located within the first welding area 1051 is the material of the second part 1212.

[0319] Referring to Figure 16(c), the material of the portion of the first frame 121 within the second welding area 1052 is a mixture of the material of the first plate 102, the material of the second plate 103, and the material of the first portion 1112. That is, the elemental composition of the portion of the first frame 121 within the second welding area 1052 may include the elements present in the material of the first plate 102, the elements present in the material of the second plate 103, and the elements present in the material of the second sub-part 1012 (i.e., the elements present in the base material). The material of the portion of the second frame 122 within the second welding area 1052 is the material of the second portion 1212.

[0320] It is understood that, in the example where there is a gap only between the first plate and the substrate, the material of the portion of the first frame 121 within the second welding area 1052 is a mixture of the material of the first plate 102 and the material of the first part 1112, such that the elemental composition of the portion of the first frame 121 within the second welding area 1052 may include the elements present in the material of the first plate 102 and the elements present in the material of the second part 1012 (i.e., the elements present in the substrate material).

[0321] In the example where the stirring head is inserted into the first and second parts, both the first part 1011 and the second part 1012 may have a first welding area 1051. The material of the first part 1112 located in the first welding area 1051 is the same as that in the example where the stirring head is inserted into the second part 1012 but not into the first part 1011, and will not be described again here.

[0322] Under the action of the stirring head, the material of the first part 1011 and the material of the second part 1212 are mixed together. The material of the second part 1212 located in the first welding area 1051 is the material of the second part 1212 and the material of the first part 1011.

[0323] For example, the substrate can be a one-piece structure, and the materials of the second part 1212 and the first sub-part 1011 are the same as the substrate material. The material of the second part 1212 located within the first welding area 1051 is the same as the substrate material. That is, the elemental composition of the portion of the second frame 122 located within the second welding area 1052 can consist only of the elements present in the material of the second frame 122.

[0324] Of course, in some other examples, the material of the second part 1212 may be different from the material of the first part 1011. In this case, the elemental composition of the part of the second frame 122 located in the second welding area 1052 may include the elements of the material of the second part 1212 and the elements of the material of the first part 1011.

[0325] The first frame 121 can form a cavity 14 with the middle plate 11, such as for accommodating the aforementioned display screen 120. The second frame 122 can form a first receiving cavity 131 with the middle plate 11, such as for accommodating the aforementioned battery. The dimension of the second frame 122 in the thickness direction (z-direction) is larger than the dimension of the first frame 121 in the thickness direction (z-direction).

[0326] It is understood that the gap 104 is formed at least between the first plate 102 and the first portion 1112 of the second split part 1012. As shown in Figure 16(a), the gap 104 is formed between the first plate 102, the second plate 103 and the first portion 1112. During the welding process along the gap in step S103, the stirring head 201 can be inserted into at least the first plate 102 and the second split part 1012. The stirring head 201, whose outer contour is a trapezoidal columnar body, has its larger end located in the first portion 1112 of the second split part 1012 and its smaller end located in the second portion 1212.

[0327] In this way, the degree of plastic deformation caused by the stirring head 201 to the first part 1112 during the welding process will be greater than that to the second part 1212. The first part 1112 with greater plastic deformation forms the first frame 121 with a smaller thickness requirement, while the second part 1212 with less plastic deformation forms the second frame 122 with a larger thickness requirement. If most of the structure is removed from the first part 1112 with more severe deformation by means of CNC cutting, the remaining small part can form the first frame 121, which helps to improve the flatness of the second frame 122 and the first frame 121, thereby improving the yield of finished products.

[0328] It should be noted that a first groove is provided at the edge where the first part and the second part meet. Figure 16 shows an example of a first groove 1111 being provided at the edge where the first part 1011 meets the second part 1212. The first groove 1111 may not extend to the second part 1212. The first groove 1111 as a whole may be a blind groove on the inner side of the first part 1011.

[0329] In some other examples, the first groove 1111 can also extend to the second part 1212, that is, the first groove 1111 is partially located in the first split part 1011 and partially located in the second part 1212. This can reduce or avoid the difficulty in controlling the position of the first groove 1111 due to process errors, which could result in a certain error distance between the first groove 1111 and the edge of the first split part 1011, causing a large number of burrs to be generated when cutting and removing the first split part 1011. This facilitates further simplification of the post-forming process of the first plate 102, better avoids the deformation of the first plate 102 during the post-forming and cutting processes, and better improves the flatness of the formed plate. In addition, it also helps to reduce the control precision of the forming position of the first groove 1111, making it easier to process and reducing processing difficulty and cost.

[0330] Figure 16a is a partial flowchart of another method for forming a middle frame according to an embodiment of this application, and Figure 16b is a cross-sectional view of another middle frame according to an embodiment of this application.

[0331] For example, as shown in Figure 16a, Figure (d) illustrates a partial structural diagram after step S103 above, where the first plate 102, the second plate 103, and the base 101 are welded along the seam. By moving the cutting along the circumferential direction of the second split portion 1012 in the removal area S2 shown in the figure, the portion of the structure on the side of the first split portion 1011 located away from the first plate 102 in the first groove 1111 can be removed, thus separating the first split portion 1011 from the second split portion 1012. It is understood that after removing the first split portion 1011, a portion of the structure of the first groove will remain on the second portion 1212.

[0332] The first sheet 102 forms at least a portion of the middle plate 11, and the second split portion 1012 forms at least a portion of the frame 12. The first portion 1112 of the second split portion 1012 can form the first frame 121 of the frame 12, and the second portion 1212 of the second split portion 1012 can form the second frame 122 of the frame 12. A portion of the first groove structure is retained on the second frame 122, as shown in Figure 16a(e), and this portion of the first groove serves as the second groove 1221. Referring to Figure 16b, the inner side surface of the formed second frame 122 (the side facing or surrounding the first receiving cavity 131) has the second groove 1221, which is located between the side of at least a portion of the middle plate 11 facing (or surrounding) the first receiving cavity 131 and the portion of the second frame 122.

[0333] The overall outer contour of the second groove 1221 can be annular, and the second groove 1221 surrounds the inner side of the second frame 122. The cross-sectional shape of the second groove 1221 (such as a cross-section made along a plane parallel to the thickness direction) can be a regular shape such as a rectangle or an arc, or it can be an irregular shape.

[0334] This application embodiment also provides a middle frame 10, which can be a middle frame 10 prepared by the above-described middle frame 10 molding method.

[0335] Figure 17 is a partially enlarged cross-sectional view of the middle frame in Figure 14.

[0336] Referring to Figure 17, the middle frame 10 includes a middle plate 11 and a side frame 12. The side frame 12 is arranged around the middle plate 11. The side frame 12 and the middle plate 11 can form one or more receiving cavities, which can be used to accommodate various components of the assembled electronic device.

[0337] For example, at least a portion of the frame 12 and at least a portion of the middle plate 11 may form a first receiving cavity 131, which may be used to receive a battery.

[0338] The at least part of the frame 12 and the at least part of the middle plate 11 can be welded together to form an integral structural component. For example, the at least part of the frame 12 and the at least part of the middle plate 11 can be prepared by steps S101 to S106 in the above-described middle frame forming method. The at least part of the middle plate 11 and the at least part of the frame 12 have a second welding area 1052.

[0339] For example, the dashed area in Figure 17 illustrates the second welding area 1052, in which at least part of the material of the middle plate 11 and at least part of the material of the frame 12 are mixed together to achieve atomic bonding and form an integral structure, so that at least part of the middle plate 11 and at least part of the frame 12 are connected at the position of the second welding area 1052, and at least part of the middle plate 11 and at least part of the frame 12 form an integral middle frame 10.

[0340] At least some of the middle plates 11 in the middle frame 10 have high flatness and thinness, which can reduce the thickness of the middle plate 11 while ensuring the quality of the middle plate 11. This is beneficial to increasing the thickness space of the internal cavity (such as the first receiving cavity 131) of the middle frame 10, and to realizing the thinning design of electronic devices.

[0341] The aforementioned substrate, first plate, and second plate are used to prepare the mid-frame as shown in Figure 17 using the aforementioned mid-frame forming method. The substrate, first plate, and second plate are welded together by friction stir welding to form a first welding area. After cutting and post-shaping processes, the substrate ultimately forms at least a portion of the frame, and the first plate forms at least a portion of the mid-frame. This means that at least a portion of the mid-frame and at least a portion of the frame are welded together by friction stir welding. As described above, after cutting and post-shaping processes, a portion of the first welding area is cut away to form a second welding area 1052, creating a second welding area 1052 between at least a portion of the mid-frame and at least a portion of the frame, as shown in Figure 17. The second welding area 1052 has a notch structure 1053 formed by cutting and other processes (as shown in Figures 16 and 16a). The first welding area is a complete welding area, such as the cross-sectional shape of the first welding area being a trapezoidal columnar cross-section. The second welding area 1052 is an incomplete welding area, with a notch structure 1053 present after cutting. The cross-sectional shape of the second welding area 1052 is the missing part of the trapezoidal columnar cross-section.

[0342] For example, the thickness of at least a portion of the middle plate 11 can be less than or equal to 0.3 mm. Making at least a portion of the middle plate 11 thinner is beneficial to increasing the space of the first receiving cavity 131 in the thickness direction (z direction), which is beneficial to meeting the thinning design requirements of electronic devices.

[0343] For example, the thickness of at least a portion of the middle plate 11 may be less than or equal to 0.2 mm, making at least a portion of the middle plate 11 thinner, further increasing the space of the first receiving cavity 131, which is more conducive to realizing the thinning design of electronic devices.

[0344] For example, the thickness of at least a portion of the middle plate 11 can be less than or equal to 0.15 mm, which realizes an ultra-thin design of at least a portion of the middle plate 11, allowing the first receiving cavity 131 to have a larger space, and also realizing an ultra-thin design of the electronic device.

[0345] In some examples, a portion of the middle plate 11 and a portion of the side frame 12 in the middle frame 10 can be obtained using the aforementioned middle frame forming method. That is, the portion of the middle plate 11 is formed using the first sheet material, and the portion of the middle plate 11 and the portion of the side frame 12 form a first receiving cavity 131. Other portions of the middle plate and other portions of the side frame in the middle frame can also form other receiving cavities, such as the second, third, and fourth receiving cavities mentioned above. The portion of the middle plate 11 that forms the first receiving cavity 131 is a middle plate 11 with high flatness and thinness, such as a thickness of less than or equal to 0.3 mm (or 0.2 mm, or 0.15 mm).

[0346] In the example where the first receiving cavity 131 is used to receive the battery, the first receiving cavity 131 can be used to receive the entire battery, and the first receiving cavity 131 can be the battery compartment of an electronic device. The middle plate 11 in this part can serve as the entire bottom plate of the battery compartment, playing a role in supporting and fixing the battery.

[0347] Alternatively, the first receiving cavity 131 can also be used to receive the battery, and the first receiving cavity 131 can be part of the battery compartment of an electronic device. For example, the aforementioned partial middle plate 11 and partial frame 12 form the first receiving cavity 131, which together with other receiving cavities formed by other partial middle plates and other partial frames constitutes the battery compartment, such as together with the aforementioned second receiving cavity to constitute the battery compartment.

[0348] This middle plate 11, together with other middle plates, serves as the bottom plate of the battery compartment, supporting and fixing the battery. For example, the area of ​​this middle plate 11 can be 30% or more of the total bottom plate area, which can effectively increase the battery compartment space or reduce the thickness of the electronic device.

[0349] For example, the area of ​​the middle plate 11 can be greater than or equal to 10cm*10cm, which can also effectively increase the battery compartment space or reduce the thickness of electronic devices.

[0350] Of course, in some other examples, the entire middle plate 11 of the middle frame 10 can be obtained by the above-described middle frame forming method, that is, the entire middle plate 11 of the middle frame 10 can be formed using the first plate.

[0351] In some examples, to ensure the mechanical properties of the middle plate 11, the elastic modulus of at least a portion of the middle plate 11 can be greater than or equal to the elastic modulus of at least a portion of the frame 12, ensuring that the middle plate 11 has strong rigidity and hardness, and ensuring the mechanical properties of the middle plate 11 and the middle frame 10 under the condition of achieving at least a portion of the middle plate 11 thinning.

[0352] For example, at least a portion of the middle plate 11 may have an elastic modulus greater than or equal to 90 GPa. This ensures that the middle plate 11 has high hardness and rigidity, thereby giving the middle frame 10 high mechanical properties.

[0353] For example, at least a portion of the middle plate 11 may have an elastic modulus greater than or equal to 100 GPa, which helps to further enhance the mechanical strength of the middle plate 11 and make the middle frame 10 more reliable.

[0354] In some examples, the yield strength of at least a portion of the middle plate 11 can be greater than or equal to the yield strength of at least a portion of the frame 12, ensuring that the middle plate 11 has strong rigidity and hardness, and achieving the thinning of at least a portion of the middle plate 11 while ensuring the mechanical properties of the middle frame 10.

[0355] In some examples, the micro Vickers hardness of at least a portion of the middle plate 11 can be greater than or equal to the micro Vickers hardness of at least a portion of the frame 12, so that the middle plate 11 has strong rigidity and hardness, and the mechanical properties of the middle frame 10 are guaranteed under the condition of thinning design.

[0356] In some examples, at least part of the material of the middle plate 11 may include one or more of aluminum-based composite materials and magnesium-based composite materials, so that the middle plate 11 can have higher hardness and rigidity, ensuring the high strength and high reliability of the middle frame 10.

[0357] In some examples, the material of the middle plate 11 may also include reinforcing materials, which can further enhance the strength and rigidity of the middle plate 11, giving the middle frame 10 higher mechanical properties.

[0358] For example, the reinforcing material may include ceramic particles, which have a significant reinforcing effect, enabling the middle plate 11 and the middle frame 10 to have better mechanical strength. Of course, in some other examples, the reinforcing material may also be other types of materials, such as fiber materials, nanomaterials, metal powders, etc.

[0359] In some examples, the material of the frame 12 may include one or more of the following: metal composite materials, aluminum alloy materials, and magnesium alloy materials, giving the frame 12 good mechanical properties and aesthetics. Of course, in some other examples, the material of the frame 12 may also be other types of metals or metal alloy materials.

[0360] In some examples, as shown in Figure 17, the border 12 may have a first frame 121 and a second frame 122. For example, the above-described mid-frame forming method can be used to form the first frame 121 of the second segment of the base 12 by using the first part of the second segment and the second part by forming the second frame 122 of the border 12. Specific forming methods can be found above and will not be repeated here.

[0361] Along the thickness direction (z-direction), the first frame 121 and the second frame 122 can be located on opposite sides of the middle plate 11. A portion of the first frame 121 can be arranged around the outside of the middle plate 11, and another portion of the first frame 121 can protrude from one side of the middle plate 11 along the thickness direction. That is, along the thickness direction (z-direction), the height of a portion of the first frame 121 is higher than the height of the middle plate 11, creating a height difference between the first frame 121 and the middle plate 11, and the first frame 121 and the middle plate 11 can form a cavity 14.

[0362] The second frame 122 can be provided to protrude from the other side of the middle plate 11 in the thickness direction, that is, along the thickness direction (z direction), the height of the second frame 122 is higher than the height of the middle plate 11, and there is a height difference between the second frame 122 and the middle plate 11. The second frame 122 and the middle plate 11 can form a first receiving cavity 131.

[0363] As shown in Figure 17, the first frame 121 may have a portion of the second welding area 1052, and the second frame 122 may also have a portion of the second welding area 1052. The elemental composition of the first frame 121 located in the second welding area 1052 is different from the elemental composition of the second frame 122 located in the second welding area 1052.

[0364] The elemental composition of the portion of the first frame 121 located within the second welding zone 1052 may include elements of the material of the middle plate 11 (i.e., the material of the first plate in the above-described middle frame forming method), elements of the material of the second plate in the above-described middle frame forming method, and elements of the material of the first frame 121 (i.e., the material of the substrate in the above-described middle frame forming method).

[0365] The elemental composition of the portion of the second frame 122 located within the second welding zone 1052 can be composed of the elements of the material of the second frame 122 (i.e., the material of the substrate in the above-described middle frame forming method).

[0366] Alternatively, the elemental composition of the portion of the second frame 122 located within the second welding zone 1052 may include the elements of the material of the second part of the substrate and the elements of the material of the first split part in the above-described middle frame forming method.

[0367] Taking the elemental composition of the second frame 122 within the second welding area 1052 as an example, which is composed of the elements present in the material of the second frame 122. In some examples, the main elements included in at least a portion of the middle plate 11 and at least a portion of the frame 12 may be the same.

[0368] For example, at least a portion of the material of the middle plate 11 (the material of the first plate in the above-described middle frame forming method) is mainly aluminum-based composite material, and at least a portion of the material of the frame 12 (the material of the matrix in the above-described middle frame forming method) is mainly aluminum alloy. The main element of both the middle plate 11 and the frame 12 can be aluminum. The percentage content of the main element in the second welding area 1052 is between the percentage content of the main element in the frame 12 and the percentage content of the main element in the middle plate 11.

[0369] In some examples, a second groove 1221 (see FIG. 16b) is provided on the inner side surface of the second frame 122 (the side facing the first receiving cavity 131), and the second groove 1221 is disposed around the inner side surface of the second frame 122. The second groove 1221 is located between at least a portion of the side of the middle plate 11 facing the first receiving cavity 131 and a portion of the second frame 122. The forming method, outer contour shape, and cross-sectional shape of the second groove 1221 can be found above and will not be repeated here.

[0370] The setting of the second groove 1221 on the second frame 122 helps to better reduce or avoid the deformation of the middle plate 11 during the processing of the middle frame 10, ensuring that the middle plate 11 has high flatness, and also helps to reduce processing difficulty and processing cost.

[0371] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, an indirect connection through an intermediate medium, or the internal connection of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances. The terms "first," "second," "third," "fourth," etc. (if present) are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0372] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of this application, and are not intended to limit them. Although the embodiments of this application have been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A method for forming a middle frame, characterized in that, include: A substrate, a first plate, and a second plate are provided. The substrate includes a first segment and a second segment. A portion of the second segment surrounds the first segment, and a portion of the second segment protrudes from one side of the first segment. The second segment and the first segment form a receiving groove. The first plate is placed in the receiving groove, and the second plate is stacked on the first plate, with at least a gap between the outer side of the first plate and the inner side of the second split part; Welding is performed along the seam to form a first weld zone between at least the first plate and the substrate; Remove the second sheet material; Remove the portion of the structure located between the first split portion and the second split portion on the substrate to disconnect the first split portion and the second split portion, and remove the first split portion; The first sheet material is made into at least a middle plate, and the second split part is made into at least a border to form an integral middle frame. At least a portion of the border is disposed around at least a portion of the middle plate, and at least a portion of the border and at least a portion of the middle plate form a first receiving cavity.

2. The method according to claim 1, characterized in that, The step of placing the first plate in the receiving groove and stacking the second plate on the first plate includes: The second plate is positioned within the receiving groove, and the gap exists between the outer side of the first plate, the outer side of the second plate, and the inner side of the second split portion. The welding along the gap to form a first welding area between at least the first plate and the substrate includes: welding the first plate, the second plate, and the substrate along the gap to form a first welding area between the first plate, the second plate, and the substrate; The removal of the second plate material includes: removing a portion of the structure within the first welding area that is connected to the second plate material, thereby disconnecting the second plate material from the substrate.

3. The method according to claim 1, characterized in that, The step of stacking the second board on the first board includes: covering a portion of the first board with the second board to expose at least a portion of the gap between the first board and the substrate; After the second plate is stacked on the first plate, and before the welding along the gap, the method further includes: pressing the second plate against the first plate; The welding along the gap to form a first welding area between at least the first plate and the substrate includes: welding the first plate and the substrate along the gap to form the first welding area between the first plate and the substrate.

4. The method according to claim 1 or 2, characterized in that, The welding along the gap includes: The welding is performed along the gap using friction stir welding, with the side containing the first plate being the forward side of the friction stir welding process.

5. The method according to claim 4, characterized in that, After providing the substrate and before placing the first plate material in the receiving groove, the method further includes: A first groove is formed at the edge where the first split part meets the second split part. At least a portion of the first groove is a blind groove on the inner side of the first split part, and the first groove surrounds the inner side of the second split part. The removal of the portion of the structure located between the first split portion and the second split portion on the substrate includes: removing the portion of the structure located on the side of the first split portion away from the first plate material in the first groove.

6. The method according to any one of claims 1-4, characterized in that, The second split portion includes a first part and a second part, wherein the first part protrudes from one side of the second part, and the second part surrounds the outside of the first split portion; The step of forming at least a partial border of the second split portion includes: a first frame that forms the border of the first portion, a second frame that forms the border of the second portion, and the second frame and the middle plate forming the first receiving cavity.

7. The method according to claim 4, characterized in that, The substrate further includes a third sub-section, which is located on one side of the first sub-section and the second sub-section; After welding along the seam, the method further includes: A welding endpoint structure is formed within the third segment; A through hole is formed at the location of the weld endpoint structure to remove the weld endpoint structure; The third segment is formed into part of the middle plate and part of the frame, and part of the frame and part of the middle plate form a second receiving cavity, and the through hole is located in the second receiving cavity.

8. The method according to any one of claims 1-7, characterized in that, The elastic modulus of the first plate is greater than or equal to the elastic modulus of the second plate and the matrix; and / or, The yield strength of the first plate material is greater than or equal to the yield strength of the second plate material and the matrix material; and / or, The micro Vickers hardness of the first plate is greater than or equal to the micro Vickers hardness of the second plate and the matrix.

9. The method according to any one of claims 1-8, characterized in that, The material of the first plate includes one or more of aluminum-based composite materials and magnesium-based composite materials.

10. The method according to any one of claims 1-9, characterized in that, The materials of the second plate and the substrate include one or more of metal composite materials, aluminum alloy materials, and magnesium alloy materials.

11. The method according to any one of claims 1-10, characterized in that, At least part of the thickness of the middle plate is less than or equal to 0.3 mm.

12. The method according to any one of claims 1-11, characterized in that, At least part of the thickness of the middle plate is less than or equal to 0.15 mm.

13. A middle frame, characterized in that, include: middle plate; A frame surrounds the middle plate, at least a portion of the frame and at least a portion of the middle plate are welded together to form an integral structural component, a second welding area is provided at the position where at least a portion of the middle plate meets at least a portion of the frame, and at least a portion of the frame and at least a portion of the middle plate form a first receiving cavity; At least part of the thickness of the middle plate is less than or equal to 0.3 mm.

14. The middle frame according to claim 13, characterized in that, At least part of the thickness of the middle plate is less than or equal to 0.2 mm.

15. The middle frame according to claim 13, characterized in that, At least part of the thickness of the middle plate is less than or equal to 0.15 mm.

16. The middle frame according to any one of claims 13-15, characterized in that, At least a portion of the frame includes a first frame and a second frame. The first frame is disposed around at least a portion of the middle plate. The first frame protrudes from one side of at least a portion of the middle plate, and the second frame protrudes from the other side of at least a portion of the middle plate. The second frame and at least a portion of the middle plate form the first receiving cavity. The first frame and the second frame each have a second welding area. The elemental composition of the first frame located in the second welding area is different from that of the second frame located in the second welding area.

17. The middle frame according to claim 16, characterized in that, The second frame has a second groove on the side facing the first receiving cavity, and the second groove is located between at least a portion of the middle plate facing the first receiving cavity and a portion of the second frame.

18. The middle frame according to any one of claims 13-17, characterized in that, At least a portion of the middle plate and at least a portion of the frame are formed by friction stir welding to form the second welding area, the second welding area having a notched structure after cutting.

19. The middle frame according to any one of claims 13-18, characterized in that, The elastic modulus of at least a portion of the middle plate is greater than or equal to the elastic modulus of at least a portion of the frame; and / or, The yield strength of the material of at least a portion of the middle plate is greater than or equal to the yield strength of the material of at least a portion of the frame; And / or, The micro Vickers hardness of at least a portion of the middle plate is greater than or equal to the micro Vickers hardness of at least a portion of the frame.

20. The middle frame according to any one of claims 13-19, characterized in that, The material of at least part of the middle plate includes one or more of aluminum-based composite materials and magnesium-based composite materials.

21. The middle frame according to any one of claims 13-20, characterized in that, The material of at least part of the frame includes one or more of the following: metal composite materials, aluminum alloy materials, and magnesium alloy materials.

22. An electronic device, characterized in that, It includes a display screen and a mid-frame as described in any one of claims 13-21, wherein the display screen is located on one side of the mid-frame.

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