Rear case member for mobile terminal, manufacturing method therefor, and mobile terminal

Abstract

Provided are a rear case member for a mobile terminal, a manufacturing method therefor, and a mobile terminal. The rear case member comprises a rear case body and a supporting structure, wherein the rear case body comprises a frame portion and a back plate portion, which jointly define an accommodating cavity; the supporting structure is disposed within the accommodating cavity, is welded to the inner wall of the frame portion, and is either welded to or integrally connected with the inner wall of the back plate portion; in addition, the supporting structure and the rear case body together define at least one positioning recess on the inner side of the rear case member. In the technical solutions of the embodiments of the present application, the rear case member is applied to a mobile terminal, thereby being conducive to improving the reliability of the product structure of the mobile terminal.

Description

Rear housing member for mobile terminal and manufacturing method thereof, and mobile terminal

[0001] Cross-reference to related applications

[0002] This application claims priority to the Chinese Patent Application No. 202411260063.0, filed on September 9, 2024, and entitled "Rear housing member for mobile terminal and manufacturing method thereof, and mobile terminal", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0003] Embodiments of the present application relate to the technical field of mobile terminals, and in particular to a rear housing member for a mobile terminal, a manufacturing method thereof, and a mobile terminal. BACKGROUND

[0004] With the continuous improvement of technology, mobile terminals are widely used in various aspects of people's lives due to their rich functions, convenient use, small size, light weight, and other characteristics. The rear shell is a main supporting component of the mobile terminal, which can bear, install, or limit some other components of the mobile terminal. In addition, the rear shell is also a key factor affecting the appearance, texture, and wear and corrosion resistance of the mobile terminal. Due to the complex and variable use scenarios of mobile terminals, the design of the rear shell is a key aspect of determining the structural reliability of the mobile terminal product. SUMMARY

[0005] Embodiments of the present application provide a rear housing member for a mobile terminal, a manufacturing method thereof, and a mobile terminal to improve the structural reliability of the mobile terminal.

[0006] According to an aspect of embodiments of the present application, a rear housing member for a mobile terminal is provided, which includes a rear housing body and a support structure, wherein: the rear housing body includes a frame portion and a backboard portion, and the frame portion and the backboard portion define a receiving cavity; the support structure is arranged in the receiving cavity, the support structure is welded with an inner wall of the frame portion, and the support structure is welded or integrally connected with an inner wall of the backboard portion, and the support structure and the rear housing body as a whole define at least one positioning recess on the inner side of the rear housing member.

[0007] According to the rear shell member, one or more positioning recesses can be defined on the inner side of the rear shell member based on the design of the support structure, so that the following technical effects can be achieved. On the one hand, the positioning recesses can be used to reliably position the electronic components of the mobile terminal, thereby reducing the assembly design difficulty of the electronic components, improving the assembly reliability, and further improving the product structure reliability of the mobile terminal. On the other hand, the support structure is welded to the inner wall of the frame portion and welded or integrally connected to the inner wall of the back plate portion, so that the structural strength of the rear shell member can be improved, thereby also being conducive to improving the product structure reliability of the mobile terminal. In addition, the processing and manufacturing of the support structure can be realized through various process schemes, so that the manufacturing process selection of the rear shell member can be more diverse and flexible, thereby being conducive to improving the manufacturing precision and reducing the manufacturing cost.

[0008] In some embodiments, the support structure includes a first protruding structure welded to the inner wall of the frame portion, and a second protruding structure welded or integrally connected to the inner wall of the back plate portion. Since the first protruding structure and the second protruding structure are in a protruding shape, corresponding recesses can be formed between the protrusions, such as the positioning recesses described above.

[0009] In some embodiments, the first protruding structure and the inner wall of the back plate portion are not connected to each other, or the first protruding structure and the inner wall of the back plate portion are integrally connected, or at least a portion of the first protruding structure is welded to the inner wall of the back plate portion. According to the specific structural design of the support structure and the selected manufacturing process, the first protruding structure and the inner wall of the back plate portion can have the above different forms of connection relationship.

[0010] In some embodiments, at least a portion of the first protruding structure is in a strip shape, or at least a portion of the second protruding structure is in a strip shape, or at least a portion of the second protruding structure is in a boss shape. According to the specific structural design of the support structure, the first protruding structure and the second protruding structure can have various design shapes.

[0011] In some embodiments, the support structure and the entire rear shell body define a plurality of positioning recesses on the inner side of the rear shell member, and at least two of the plurality of positioning recesses have no overlap in the orthographic projection on the back plate portion. In these embodiments, each positioning recess can be arranged flat, that is, the orthographic projection on the back plate portion is not overlapped.

[0012] In some embodiments, the at least two positioning recesses are arranged along a direction orthogonal to the back plate portion, and a projection of one of the at least two positioning recesses on the back plate portion overlaps with a projection of another of the at least two positioning recesses on the back plate portion, i.e., the projections of the two positioning recesses on the back plate portion have an overlapping portion. In these embodiments, the arrangement of the positioning recesses allows some electronic components to be arranged in a stacked manner along the direction orthogonal to the back plate portion.

[0013] In some embodiments, one part of the support structure serves as a mechanical reinforcing structure of the back cover member. In this way, the deformation resistance of the back cover member can be improved, thereby improving the structural strength of the back cover member.

[0014] In some embodiments, the support structure is welded to the inner wall of the frame portion by a friction stir welding process; and / or, the support structure is welded to the inner wall of the back plate portion by a friction stir welding process. Compared with fusion welding, friction stir welding can generate a weld with fewer defects and is more compatible with welding parameters and welding materials.

[0015] In some embodiments, the support structure is integrally connected to the inner wall of the back plate portion; the frame portion includes a plurality of spliced segments that are combined in a frame shape, wherein the back plate portion is combined with the plurality of spliced segments, and the support structure is welded to the inner wall of each of the plurality of spliced segments. The back cover member of this embodiment not only has the beneficial effects described above, but also the back plate portion, the support structure, and the plurality of spliced segments can be obtained by cutting and bending processing or numerical control milling processing of a plate piece, which is relatively simple in manufacturing process and is conducive to saving production materials.

[0016] In some embodiments, the back plate portion and at least one of the plurality of spliced segments have a gap for electromagnetic waves to pass through. In this way, the design of the antenna system of the mobile terminal can be facilitated.

[0017] In some embodiments, the back plate portion is connected to each part of the perimeter of the frame portion; or the frame portion includes a first frame edge portion and a second frame edge portion, wherein the back plate portion is connected to the first frame edge portion and is not connected to the second frame edge portion, and the second frame edge portion is used to connect a back cover decorative surface layer of the mobile terminal. In the embodiments of the present application, the specific shapes of the frame portion and the back plate portion are not limited and can be flexibly designed according to product design requirements.

[0018] In some embodiments, the at least one positioning recess is used to limit the position of at least one electronic component of the mobile terminal, and the at least one electronic component includes one or more of a main board, a sub-board, a camera module, a flash, a laser focusing sensor, an ambient light sensor, a speaker, an earpiece, a microphone, a wireless charging module, a chip card, a motor, or a battery. The rear shell member can be designed flexibly according to the hardware configuration of the mobile terminal product, thereby providing reliable position limitation for some electronic components of the mobile terminal, reducing the assembly design difficulty of the electronic components, and improving the assembly reliability of the electronic components.

[0019] In some embodiments, the frame portion and the back plate portion each include a first metal layer and a second metal layer that are connected in a composite manner, the first metal layer is located on a side of the second metal layer that faces away from the accommodation cavity, the main element of the first metal layer is different from the main element of the second metal layer, and the support structure has the same main element as the second metal layer. The rear shell body is made of two metal materials with different main elements, which can have the material advantages of both. The support structure has the same main element as the second metal layer, which can reduce or even avoid the welding weakness caused by the difference in thermal conductivity and linear expansion coefficient of the materials.

[0020] In some embodiments, the thickness of the first metal layer is less than the thickness of the second metal layer, and the hardness of the first metal layer is greater than the hardness of the second metal layer. In this way, the rear shell member not only has good surface wear resistance, but also meets the structural strength design requirements. In addition, the thickness of the second metal layer is designed to be greater than the thickness of the first metal layer, which makes it easier to achieve reliable connection of the support structure with the frame portion and the back plate portion, and the support structure is also more convenient to manufacture.

[0021] In some embodiments, the side of the first metal layer that faces away from the second metal layer has a surface treatment layer. The surface treatment layer can improve the wear resistance, corrosion resistance, stain resistance, or fingerprint resistance of the appearance surface of the rear shell member, and can also improve the appearance effect of the rear shell member, thereby making the product design more competitive.

[0022] In some embodiments, the material of the first metal layer includes titanium, titanium alloy, or stainless steel, the material of the second metal layer includes aluminum alloy, and the material of the support structure includes aluminum alloy. Titanium has good corrosion resistance, high strength, and light weight; titanium alloy has good corrosion resistance, high strength, and good toughness; steel has high strength, good wear resistance, easy processing, and low cost; aluminum alloy has low density, good mechanical properties, good processing performance, non-toxicity, easy recycling, excellent thermal conductivity, and excellent corrosion resistance.

[0023] According to an aspect of an embodiment of the present application, a manufacturing method of a rear shell member for a mobile terminal is provided, and the manufacturing method includes:

[0024] The rear shell body includes a frame part and a back plate part, wherein the frame part and the back plate part are integrally connected and define a receiving cavity;

[0025] The middle plate is welded to the inner wall of the frame part and welded to the inner wall of the back plate part; and

[0026] Part of the material of the middle plate is removed, and at least part of the welding structure between the middle plate and the frame part and at least part of the welding structure between the middle plate and the back plate part are retained to obtain a support structure, wherein the support structure is welded to the inner wall of the frame part and the inner wall of the back plate part, and the support structure and the whole rear shell body define at least one positioning recess inside the rear shell member.

[0027] The rear shell member manufactured by the manufacturing method of the above-mentioned embodiments of the present application can be applied to a mobile terminal, and can provide reliable positioning for electronic components of the mobile terminal, thereby reducing the assembly design difficulty of the electronic components, improving the assembly reliability of the electronic components, and further improving the product structure reliability of the mobile terminal. Since the support structure is welded to the inner wall of the frame part and welded to the inner wall of the back plate part, the structural strength of the rear shell member can be improved, thereby facilitating the improvement of the product structure reliability of the mobile terminal. In addition, since the support structure is obtained by removing part of the material of the middle plate, the manufacturing process is relatively simple, the manufacturing cost is relatively low, and accurate structure parameters can be easily obtained, thereby further improving the assembly reliability of the electronic components in the mobile terminal.

[0028] In some embodiments, welding the middle plate to the inner wall of the frame part includes welding the middle plate to the inner wall of the frame part along a first preset welding trajectory line by a friction stir welding process; and / or welding the middle plate to the inner wall of the back plate part includes welding the middle plate to the inner wall of the back plate part along a second preset welding trajectory line by a friction stir welding process. The first preset welding trajectory line and the second preset welding trajectory line can be designed according to the specific structure size parameters of the support structure. For example, in some embodiments, the first preset welding trajectory line can be in a closed shape, a line segment shape, or a combination of multiple line types; and the second preset welding trajectory line can be in a closed shape, a line segment shape, or a combination of multiple line types.

[0029] In some embodiments, a rear shell body is provided, including: providing a composite plate material, the composite plate material including a first metal layer and a second metal layer having different main elements; and forming the composite plate material into a rear shell body having a receiving cavity, wherein the first metal layer is located on the side of the second metal layer away from the receiving cavity. The rear shell body is made of two metal materials with different main elements, which can have the material advantages of both.

[0030] According to an aspect of the embodiments of the present application, there is provided a manufacturing method of a rear shell member for a mobile terminal, comprising:

[0031] providing a plate member;

[0032] removing part of the thickness of the peripheral region of the plate member to obtain a first part and a second part with different thicknesses, wherein the first part surrounds the second part, and the thickness of the first part is less than that of the second part;

[0033] folding the first part towards the second part and adhering the first part to the second part;

[0034] welding the side walls of the first part and the second part; and

[0035] removing part of the material of the second part and retaining at least part of the welding structure of the first part and the second part to obtain a rear shell body and a support structure, wherein the rear shell body comprises a frame part and a back plate part which are integrally connected and define a receiving cavity, the support structure is located in the receiving cavity and is welded to the inner wall of the frame part and integrally connected to the inner wall of the back plate part, and the support structure and the rear shell body as a whole define at least one positioning recess on the inner side of the rear shell member.

[0036] The rear shell member manufactured by the manufacturing method of the embodiments of the present application can provide reliable positioning for the electronic components of the mobile terminal, thereby reducing the assembly design difficulty of the electronic components, improving the assembly reliability of the electronic components, and further improving the product structure reliability of the mobile terminal. Since the support structure is welded to the inner wall of the frame part and integrally connected to the inner wall of the back plate part, the structural strength of the rear shell member can be improved, thereby facilitating the improvement of the product structure reliability of the mobile terminal. In addition, since the support structure is obtained by removing part of the material of the second part, the manufacturing process is relatively simple and the manufacturing cost is relatively low, and accurate structure parameters can be easily obtained, thereby further improving the assembly reliability of the electronic components in the mobile terminal.

[0037] In some embodiments, the manufacturing method further comprises, after folding the first part towards the second part and adhering the first part to the second part, and before welding the side walls of the first part and the second part, removing part of the material of the first part and / or the second part to make the first part flush with the second part. Through this step, on the one hand, the size accuracy requirement of the provided plate member, the machining accuracy requirement of the step of removing part of the material of the plate member, or the forming accuracy requirement of the stretching and bending in the folding step can be appropriately reduced, and on the other hand, a higher-precision intermediate prefabricated part can be obtained.

[0038] In some embodiments, the welding the side wall of the first part to the second part includes welding the side wall of the first part to the second part along a preset welding trajectory line by a friction stir welding process. In some embodiments, the preset welding trajectory line can be in a closed shape, such that the first part and the second part are welded around the entire circumference. In some embodiments, the preset welding trajectory line can also be in a linear segment shape, such that the first part and the second part are welded only in the areas required by the local design.

[0039] In some embodiments, a plate member is provided, including: providing a composite plate, the composite plate including a first metal layer and a second metal layer having different major elements; and removing a portion of thickness of material from a peripheral region of the plate member, including: removing a portion of thickness of material from a peripheral region of the second metal layer. The back shell member is made of two metal materials having different major elements, and can have the advantages of both materials.

[0040] According to an aspect of the embodiments of the present application, there is provided a manufacturing method of a back shell member for a mobile terminal, the manufacturing method comprising:

[0041] providing a middle plate and a plurality of splicing segments;

[0042] splicing the plurality of splicing segments into a frame portion, and welding the middle plate to an inner wall of the frame portion; and

[0043] removing a portion of material of the middle plate and retaining at least a portion of the welding structure of the middle plate and the frame portion, to obtain a back shell body and a support structure, wherein the back shell body includes a back plate portion and the frame portion defining a receiving cavity, the support structure is located in the receiving cavity and is welded to the inner wall of the frame portion and integrally connected to an inner wall of the back plate portion, and the support structure and the back shell body as a whole define at least one positioning recess inside the back shell member.

[0044] The back shell member manufactured by the manufacturing method of the embodiments of the present application and applied to a mobile terminal can provide reliable positioning for electronic components of the mobile terminal, thereby reducing the assembly design difficulty of the electronic components, improving the assembly reliability of the electronic components, and further improving the product structure reliability of the mobile terminal. Since the support structure is welded to the inner wall of the frame portion and integrally connected to the inner wall of the back plate portion, the structural strength of the back shell member can be improved, thereby facilitating the improvement of the product structure reliability of the mobile terminal. In addition, since the frame portion is spliced by the plurality of splicing segments, the processing and manufacturing are relatively simple, and the design of an antenna system of the mobile terminal is facilitated, for example, a gap for electromagnetic waves to pass through is designed between the back plate portion and at least one splicing segment.

[0045] In some embodiments, the welding of the middle plate to the inner wall of the frame portion includes: welding the middle plate to the inner wall of the frame portion along a preset welding track line by a friction stir welding process. In some embodiments, the preset welding track line can be in a closed shape, so that the middle plate is welded to the frame portion at all around. In some embodiments, the preset welding track line can also be in a line segment shape, so that the middle plate is only welded to the frame portion at a local area required by design, but the welding structure is required between the middle plate and each spliced segment.

[0046] According to an aspect of the embodiments of the present application, there is provided a manufacturing method of a rear shell member for a mobile terminal, which manufacturing method comprises:

[0047] providing a rear shell body, the rear shell body comprising a frame portion and a back plate portion, wherein the frame portion and the back plate portion are integrally connected and define a receiving cavity; and

[0048] providing a support structure, welding the support structure to the inner wall of the frame portion, and welding the support structure to the inner wall of the back plate portion, wherein the support structure is a die casting, and the support structure and the rear shell body as a whole define at least one positioning recess inside the rear shell member.

[0049] The rear shell member manufactured by the manufacturing method of the embodiments of the present application can provide reliable positioning for the electronic components of the mobile terminal, thereby reducing the assembly design difficulty of the electronic components, improving the assembly reliability of the electronic components, and further improving the product structure reliability of the mobile terminal. Since the support structure is welded to the inner wall of the frame portion and welded to the inner wall of the back plate portion, the structural strength of the rear shell member can be improved, thereby being conducive to improving the product structure reliability of the mobile terminal. In addition, since the support structure is a die casting, the production efficiency is high, and accurate structure parameters can be easily obtained, thereby being conducive to further improving the assembly reliability of the electronic components in the mobile terminal.

[0050] In some embodiments, the welding of the support structure to the inner wall of the frame portion includes: welding the support structure to the inner wall of the frame portion along a first preset welding track line by a friction stir welding process; and / or, the welding of the support structure to the inner wall of the back plate portion includes: welding the support structure to the inner wall of the back plate portion along a second preset welding track line by a friction stir welding process. The first preset welding track line and the second preset welding track line can be designed according to the specific structure size parameters of the support structure. For example, in some embodiments, the first preset welding track line can be in a closed shape, a line segment shape, or a combination of multiple line types; the second preset welding track line can be in a closed shape, a line segment shape, or a combination of multiple line types.

[0051] According to an aspect of some embodiments of the present application, a mobile terminal is provided, which comprises: a back shell member product of the foregoing embodiments or a back shell member made according to the manufacturing method of the foregoing embodiments, a main board and a battery, and a display screen, wherein: the support structure and the whole of the back shell body define at least two positioning recesses on the inner side of the back shell member, the at least two positioning recesses comprising a main board positioning recess and a battery positioning recess; the main board and the battery are positioned in the main board positioning recess and the battery positioning recess in one-to-one correspondence; and the display screen is located on the front side of the main board and the battery and connected with the frame portion.

[0052] According to the mobile terminal of the embodiments of the present application, on the one hand, the design of the back shell member can provide reliable positioning for the battery and the main board of the mobile terminal, thereby reducing the assembly design difficulty of the battery and the main board, improving the assembly reliability thereof, and further improving the product structure reliability of the mobile terminal; on the other hand, since the support structure of the back shell member is welded with the inner wall of the frame portion and welded or integrally connected with the inner wall of the back plate portion, the overall structural strength of the back shell member is high, and the product structure reliability of the mobile terminal is high; on the other hand, the processing and manufacturing of the back shell member can be realized through various process schemes, thereby being conducive to improving the manufacturing precision and reducing the manufacturing cost of the mobile terminal. BRIEF DESCRIPTION OF DRAWINGS

[0053] FIG. 1 is a schematic diagram of the perspective structure of a back shell member according to some embodiments of the present application;

[0054] FIG. 2A is a schematic diagram of the cross-sectional structure of the back shell member along the A-A direction of FIG. 1 according to some embodiments of the present application (the black thick solid line is used to illustrate that the two structures are welded);

[0055] FIG. 2B is a schematic diagram of the cross-sectional structure of the back shell member along the A-A direction of FIG. 1 according to some embodiments of the present application (the black thick solid line is used to illustrate that the two structures are welded);

[0056] FIG. 3A is a schematic diagram of the simplified cross-sectional structure of the back shell member according to some embodiments of the present application (illustrating the positioning of electronic components);

[0057] FIG. 3B is a schematic diagram of the simplified cross-sectional structure of the back shell member according to some embodiments of the present application (illustrating the positioning of electronic components);

[0058] FIG. 4A is a micrograph of the welding molten pool obtained at positions C and D of FIG. 2A of the back shell member according to some embodiments of the present application (the dashed line illustrates the approximate boundary of the molten pool);

[0059] FIG. 4B is a micrograph of the welding molten pool obtained at position C of FIG. 2A of the back shell member according to some embodiments of the present application (the dashed line illustrates the approximate boundary of the molten pool);

[0060] FIG. 4C is a micrograph of a weld pool obtained at, for example, point C of FIG. 2A, of a back case member, according to some embodiments of the present application (dashed lines illustrate the approximate boundaries of the weld pool);

[0061] FIG. 4D is a micrograph of a weld pool obtained at, for example, point D of FIG. 2A, of a back case member, according to some embodiments of the present application (dashed lines illustrate the approximate boundaries of the weld pool);

[0062] FIG. 5 is a schematic diagram of a rear view of a mobile terminal, according to some embodiments of the present application;

[0063] FIG. 6A is a simplified front view of a back case member, according to some embodiments of the present application;

[0064] FIG. 6B is a cross-sectional view of the back case member of FIG. 6A, taken along line B-B, according to some embodiments of the present application (illustrating a weld pool, where the black, heavy solid line indicates a weld connection between two structures);

[0065] FIG. 6C is a cross-sectional view of the back case member of FIG. 6A, taken along line B-B, according to some embodiments of the present application (black, heavy solid line indicates a weld connection between two structures);

[0066] FIG. 7A is a flowchart of a method of fabricating a back case member, according to some embodiments of the present application;

[0067] FIG. 7B is a schematic diagram of a fabrication process for a back case member, according to some embodiments of the present application;

[0068] FIG. 8A is a flowchart of a method of fabricating a back case member, according to some embodiments of the present application;

[0069] FIG. 8B is a schematic diagram of a fabrication process for a back case member, according to some embodiments of the present application;

[0070] FIG. 9A is a flowchart of a method of fabricating a back case member, according to some embodiments of the present application;

[0071] FIG. 9B is a schematic diagram of a fabrication process for a back case member, according to some embodiments of the present application;

[0072] FIG. 10 is a flowchart of a method of fabricating a back case member, according to some embodiments of the present application;

[0073] FIG. 11 is a schematic diagram of a cross-sectional view of a mobile terminal, according to some embodiments of the present application.

[0074] 400 - mobile terminal; 100 - rear housing member; 10 - rear housing body; 11 - frame portion; 12 - back plate portion; 101 - accommodating cavity; 30 - support structure; 31, 31a, 31b - positioning recess; 32 - first protruding structure; 33 - second protruding structure; 33a - boss-like portion; 33b - strip-like portion; 110 - spliced segment; 115 - gap; 116 - molten pool; 111 - first frame edge; 112 - second frame edge; 113 - third frame edge; 114 - fourth frame edge; 13 - rear housing decorative surface layer; 102 - first metal layer; 103 - second metal layer; 104 - electronic component; 105 - display screen; 300a, 300b - middle plate; 301 - first preset welding track line; 302 - second preset welding track line; 410 - composite board; 420 - board piece; 501 - first portion; 502 - second portion; 503 - preset welding track line; 311 - main board positioning recess; 312 - battery positioning recess; 41 - main board; 42 - sub-board; 43 - battery; 700, 800, 900, 1000 - manufacturing method; S701-S703, S7011-S7012, S801-S805, S901-S903, S1001-S1002 - step. DETAILED DESCRIPTION

[0075] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the embodiments of the present application will be further described in detail below with reference to the drawings.

[0076] The terminology used in the following embodiments is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. As used in this specification and the appended claims, the singular forms "a," "an" and "the" are intended to include both singular and plural forms, unless the context clearly indicates otherwise.

[0077] Reference herein to "one embodiment" or "an embodiment" or "the" or "a" or "this" embodiment, means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the application. The appearances of the phrases "in one embodiment" or "in an embodiment" or "in the" or "in a" or "in this" embodiment in various places in the specification are not necessarily all referring to the same embodiment.

[0078] Some mobile terminals in the related art, such as mobile phones, mainly include a metal back shell, a battery, a mainboard and a display screen, etc., wherein the metal back shell has a receiving cavity, the battery, the mainboard and the display screen are arranged in the receiving cavity, and the battery and the mainboard are located between the display screen and the metal back shell. In the related art, the metal back shell is generally formed by a plate stamping process, which is a pressure processing method for separating or deforming the plate material placed between the die by using pressure.

[0079] The technical defect of the above related art is that, due to the limitation of the thickness of the metal plate and the forming process, it is generally impossible to form a more ideal convex rib for limiting the battery and the mainboard on the inner side of the metal back shell, which brings challenges to the reliable assembly of electronic components such as the battery and the mainboard, thereby possibly affecting the structural reliability of the overall product of the mobile terminal.

[0080] Therefore, the embodiments of the present application provide a back shell component for a mobile terminal and a manufacturing method thereof, and a mobile terminal, so as to improve the product structural reliability of the mobile terminal.

[0081] In the embodiments of the present application, the specific product types of the mobile terminal can include but are not limited to mobile phones, tablet computers, personal computers, wearable devices, etc. The back shell component can serve as the back shell of the mobile terminal or as one of the structural components of the back shell of the mobile terminal. When the back shell of the mobile terminal further includes other structural components, such as a back shell decorative surface layer, a camera decorative ring, a side key, etc., the present application does not make specific limitations thereto.

[0082] The embodiments of the present application will be specifically described below with reference to the accompanying drawings.

[0083] As shown in FIGS. 1, 2A and 2B, wherein FIG. 1 is a perspective structural schematic diagram of a back shell component 100 for a mobile terminal according to some embodiments of the present application, FIG. 2A is a sectional structural schematic diagram of the back shell component according to some embodiments of the present application, which is cut along the A-A direction of FIG. 1, and FIG. 2B is a sectional structural schematic diagram of the back shell component according to some other embodiments of the present application, which is cut along the A-A direction of FIG. 1.

[0084] As shown in FIG. 1, the rear shell member 100 includes a rear shell body 10 and a support structure 30 (a lead line in the figure indicates a part of the support structure 30). The rear shell body 10 includes a frame part 11 and a back plate part 12, which define a receiving cavity 101 in which the support structure 30 is arranged. As shown in FIGS. 2A and 2B, the support structure 30 is welded to the inner wall of the frame part 11, and the support structure 30 is welded to (as shown in FIG. 2A) or integrally connected to (as shown in FIG. 2B) the inner wall of the back plate part 12. Based on the design of the support structure 30, the support structure 30 and the rear shell body 10 as a whole define at least one positioning recess 31 on the inner side of the rear shell member 100.

[0085] In the embodiment of the present application, the rear shell body 10 can constitute at least part of the appearance structure of the mobile terminal, and the outer side surface thereof can serve as at least part of the appearance surface of the mobile terminal. The receiving cavity 101 can be understood as a receiving space enclosed by the frame part 11 and the back plate part 12. In the embodiment of the present application, the side of the rear shell member 100 closer to the receiving cavity 101 is defined as the inner side thereof, and the side thereof farther away from the receiving cavity 101 is correspondingly defined as the outer side thereof.

[0086] In the embodiment of the present application, the "integrally connected" of two structures (such as the frame part 11 and the back plate part 12) can be understood as that the two structures are connected together without assembly, and the two structures cannot be disassembled and separated.

[0087] In the embodiment of the present application, the support structure 30 is mainly used for bearing, mounting and limiting some electronic components of the mobile terminal, and in addition, the support structure 30 can also play a role in structurally reinforcing the whole of the rear shell member 100. As shown in FIG. 1, since the connection direction of the support structure 30 and the frame part 11 is parallel to the XY reference plane, the welding of the above-mentioned support structure 30 and the inner wall of the frame part 11 can be defined as "XY-direction connection"; since the connection direction of the support structure 30 and the back plate part 12 is along the Z direction, the welding or integrally connecting of the above-mentioned support structure 30 and the inner wall of the back plate part 12 can be defined as "Z-direction connection".

[0088] In the embodiment of the present application, the support structure 30 and the rear shell body 10 as a whole define at least one positioning recess 31 on the inner side of the rear shell member 100, which can be used to limit electronic components of the mobile terminal, wherein the types of the electronic components can include but are not limited to mainboards, sub-boards, camera modules, flash lights, laser focusing sensors, ambient light sensors, loudspeakers, earpieces, microphones, wireless charging modules, chip cards, motors, or batteries, etc.

[0089] As shown in FIG. 1, in some embodiments, the support structure 30 and the whole of the back shell body 10 define a plurality of positioning recesses 31 (only some number of the positioning recesses 31 are schematically shown by lead lines in the figure) on the inner side of the back shell member 100, which can be used to position a plurality of electronic components of the mobile terminal. The specific number, structural shape, specification size and arrangement of the plurality of positioning recesses 31 are not limited in the embodiments of the present application, and can be flexibly designed according to the hardware configuration of the mobile terminal product.

[0090] For example, in some embodiments, the shape of the positioning recess 31 can be rectangular slot shape, circular slot shape, or stepped slot shape, etc. (only some of the positioning recesses 31 in rectangular slot shape are shown in FIG. 1).

[0091] For example, as shown in FIG. 3A, which is a simplified cross-sectional structural schematic diagram of the back shell member 100 according to some embodiments of the present application, the positioning of the electronic components 104 is schematically shown. In these embodiments, the positioning recesses 31 can be arranged in a tiled manner, i.e., the orthographic projection on the back plate portion 12 is not overlapped with each other.

[0092] For example, as shown in FIG. 3B, which is a simplified cross-sectional structural schematic diagram of the back shell member 100 according to some other embodiments of the present application, the positioning of the electronic components 104 is schematically shown. In these embodiments, at least two positioning recesses 31 (such as the positioning recess 31a and the positioning recess 31b) are arranged in a direction orthogonal to the back plate portion 12, and the orthographic projection on the back plate portion 12 of one of the at least two positioning recesses 31 (such as the orthographic projection of the positioning recess 31a on the back plate portion 12) is overlapped with the orthographic projection on the back plate portion 12 of the other of the at least two positioning recesses 31 (such as the orthographic projection of the positioning recess 31b on the back plate portion 12), i.e., the orthographic projections on the back plate portion 12 of the two positioning recesses 31 have overlapping parts, so that some of the electronic components 104 can be arranged in a stacked manner in the direction orthogonal to the back plate portion 12.

[0093] It can be seen that, according to the technical solutions of the embodiments of the present application, one or more positioning recesses 31 can be defined on the inner side of the back shell member 100 based on the design of the support structure 30, so that at least the following technical effects can be obtained compared with the prior art:

[0094] On the one hand, reliable positioning can be provided for the electronic components of the mobile terminal, so as to reduce the assembly design difficulty of the electronic components, improve the assembly reliability thereof, and further improve the product structure reliability of the mobile terminal;

[0095] In another aspect, the support structure 30 is welded with the inner wall of the frame portion 11 and welded or integrally connected with the inner wall of the back plate portion 12, that is, the support structure 30 is connected with the back shell body 10 in the XY direction and the Z direction, so that the structural strength of the back shell member 100 can be improved, thereby facilitating the improvement of the product structural reliability of the mobile terminal.

[0096] In another aspect, the support structure 30 can be manufactured by various process schemes (which will be described in detail in the manufacturing method embodiments below), and the manufacturing process of the back shell member 100 can be more diverse and flexible, thereby facilitating the improvement of the manufacturing precision and the reduction of the manufacturing cost.

[0097] In the embodiments of the present application, the support structure 30 and the back shell body 10 together define at least one positioning recess 31 inside the back shell member 100, and the specific structural design form of the support structure 30 is not limited. As shown in FIG. 1, in some embodiments of the present application, the support structure 30 includes a first protruding structure 32 welded with the inner wall of the frame portion 11 and a second protruding structure 33 welded or integrally connected with the inner wall of the back plate portion 12.

[0098] The specific structural shape of the first protruding structure 32 and the second protruding structure 33 is not limited in the embodiments of the present application. In some embodiments of the present application, at least a portion of the first protruding structure 32 can be in a strip shape, at least a portion of the second protruding structure 33 can be in a boss shape, or at least a portion of the second protruding structure 33 can be in a strip shape. As shown in FIG. 1, in this embodiment, the first protruding structure 32 is in a strip shape, and the second protruding structure 33 includes a boss-shaped portion 33a and a strip-shaped portion 33b. Since the first protruding structure 32 and the second protruding structure 33 are in a protruding shape, corresponding recesses can be formed between the protrusions, for example, the positioning recess 31 described above.

[0099] According to the specific design structure of the support structure 30 and the selected manufacturing process, the first protruding structure 32 and the inner wall of the back plate portion 12 can have different forms of connection relationship.

[0100] For example, as shown in FIG. 2A, in some embodiments, the first protruding structure 32 of the support structure 30 can have no connection with the inner wall of the back plate portion 12, so that the first protruding structure 32 is only welded with the inner wall of the frame portion 11 (i.e., XY direction connection). In these embodiments, the second protruding structure 33 of the support structure 30 can be welded with the inner wall of the back plate portion 12 (i.e., Z direction connection).

[0101] For example, in some embodiments, the first protruding structure 32 of the support structure 30 is not only welded with the inner wall of the frame portion 11 (i.e., XY-direction connection), but also integrally connected with the inner wall of the back plate portion 12 (i.e., Z-direction connection). In these embodiments, the second protruding structure 33 of the support structure 30 can be integrally connected with the inner wall of the back plate portion 12 (i.e., Z-direction connection).

[0102] For example, in some embodiments, the first protruding structure 32 of the support structure 30 is not only welded with the inner wall of the frame portion 11 (i.e., XY-direction connection), but also at least a part of it can be welded with the inner wall of the back plate portion 12 (i.e., Z-direction connection). In these embodiments, the second protruding structure 33 of the support structure 30 can be welded with the inner wall of the back plate portion 12 (i.e., Z-direction connection), and the above-mentioned at least a part of the first protruding structure 32 which is welded with both the frame portion 11 and the back plate portion 12 can be located at the intersection of the first protruding structure 32 and the second protruding structure 33, as shown by F in FIG. 1.

[0103] In these embodiments, the design scheme of the support structure 30 can not only provide reliable positioning for the electronic components of the mobile terminal, but also can improve the structural strength of the back shell member 100, thereby being conducive to improving the product structural reliability of the mobile terminal, since the support structure 30 is connected with the back shell body 10 in both XY-direction and Z-direction.

[0104] In some embodiments of the present application, a part of the support structure 30 can be used as a mechanical reinforcing structure of the back shell member 100. For example, a part of the above-mentioned first protruding structure 32 and second protruding structure 33 can be designed as a strip-shaped reinforcing rib of the back shell member 100, and not used to form a positioning groove for positioning the electronic components. Such a design can improve the anti-deformation capability of the back shell member 100, thereby improving the structural strength of the back shell member 100.

[0105] In the embodiments of the present application, the support structure 30 and the frame portion 11, and the support structure 30 and the back plate portion 12 can be connected by using the same or different welding processes, which are not specifically limited in the embodiments of the present application.

[0106] In some embodiments, the support structure 30 and the inner wall of the frame portion 11 can be connected by using a friction stir welding process in the XY-direction, and the support structure 30 and the inner wall of the back plate portion 12 can be connected by using a friction stir welding process in the Z-direction.

[0107] Friction stir welding refers to using heat generated by friction between a high-speed rotating tool and a workpiece to locally melt the material to be welded. When the tool moves forward along the welding interface, the plasticized material flows from the front of the tool to the rear under the action of the rotating friction of the tool, and forms a dense solid-phase weld under the extrusion of the tool. Compared with fusion welding, friction stir welding is a solid-phase welding, so it can avoid defects such as pores, slag inclusion, and hot cracks caused by the cooling process of metal from liquid to solid during the fusion welding process. In addition, it can achieve green production, and almost no welding smoke and spatter, and almost no ultraviolet and electromagnetic radiation. Generally, friction stir welding can generate a weld with fewer defects, and is more compatible with welding parameters and welding materials.

[0108] In the embodiments of the present application, the XY-direction welding structure of the support structure 30 and the frame part 11 and the Z-direction welding structure of the support structure 30 and the back plate part 12 are respectively sliced, and then the two sliced surfaces are sequentially polished (such as using 180-mesh, 1200-mesh, and 2500-mesh sandpaper in sequence), polished (such as using 1 μm alumina powder), and subjected to metallographic corrosion (such as using Kroll reagent for 10-30 seconds). After the treatment, the microstructure of the molten pool of the friction stir welding can be observed under a microscope. The molten pool generally refers to a part of liquid metal with a certain geometric shape formed on the welding part under the action of a welding heat source. The shape of the molten pool is an important factor for judging the welding quality. Under normal circumstances, the molten pool should be roughly funnel-shaped. If the molten pool is flat, it indicates that there may be problems such as distortion or excessive heat during the welding process.

[0109] The rear shell member 100 of some embodiments of the present application is sliced at positions C and D of FIG. 2A, for example, and sequentially subjected to polishing, polishing, and metallographic corrosion, and the micrograph of the welding molten pool shown in FIG. 4A can be observed under a microscope, wherein the dashed line schematically shows the approximate boundary of the molten pool 116, and it can be seen that the microstructure features of the molten pool 116 are roughly funnel-shaped.

[0110] In some embodiments, during the manufacturing process of the rear shell member 100, the above-mentioned roughly funnel-shaped molten pool microstructure features may be partially removed due to the machining of other structural features after the welding process, so that only part of the microstructure features can be observed. For example, the rear shell member 100 of some embodiments of the present application is sliced at position C of FIG. 2A and sequentially subjected to polishing, polishing, and metallographic corrosion, and the molten pool features shown in FIG. 4B can be observed, wherein the dashed line schematically shows the approximate boundary of the molten pool 116, and it can be seen that it retains part of the roughly funnel-shaped molten pool microstructure features.

[0111] In some embodiments, in the process of manufacturing the rear shell member 100, in order to improve the mechanical properties of the rear shell member 100 product, the rear shell member 100 can be further heat treated, so that for the actual product of the rear shell member 100, after slicing at C of FIG. 2A and sequentially polishing, polishing and metallographic corrosion, the molten pool feature shown in, for example, FIG. 4C can be observed, and after slicing at D of FIG. 2A and sequentially polishing, polishing and metallographic corrosion, the molten pool feature shown in, for example, FIG. 4D can be observed, in which the dashed line schematically shows the approximate boundary of the molten pool 116. As shown in FIG. 4C, the funnel-shaped molten pool microstructure feature can only observe part of the microstructure feature under a microscope because part of the material is removed by machining, and although the inner and outer grains of the molten pool 116 have a certain growth or deformation after heat treatment, at least part of the funnel-shaped molten pool boundary feature is still retained on the metallographic phase. As shown in FIG. 4D, although the inner and outer grains of the funnel-shaped molten pool 116 have a certain growth or deformation after heat treatment, the trace of the funnel-shaped molten pool boundary is still retained on the metallographic phase.

[0112] In the embodiments of the present application, the specific shape of the frame portion 11 and the back plate portion 12 is not limited.

[0113] For example, in some embodiments of the present application, the back plate portion 12 can be connected with each part of the perimeter of the frame portion 11. As shown in the embodiment of FIG. 1, the frame portion 11 is in the shape of a rounded rectangular frame, which includes a first frame edge 111, a second frame edge 112, a third frame edge 113 and a fourth frame edge 114 connected in sequence, wherein the back plate portion 12 is integrally connected with the first frame edge 111, the second frame edge 112, the third frame edge 113 and the fourth frame edge 114.

[0114] For example, in some embodiments of the present application, the frame portion can be divided into a first frame edge portion and a second frame edge portion, wherein the back plate portion is connected to the first frame edge portion and is not connected to the second frame edge portion, and the second frame edge portion can be used to connect a back cover decorative surface layer of the mobile terminal. As shown in FIG. 5, which is a schematic diagram of the back appearance of a mobile terminal 400 according to some embodiments of the present application. As can be seen, in these embodiments, the frame portion 11 is substantially a rounded rectangular frame shape, which includes a first frame edge 111, a second frame edge 112, a third frame edge 113, and a fourth frame edge 114 connected in sequence, wherein the back plate portion 12 is integrally connected to a portion of the first frame edge 111, a portion of the third frame edge 113, and the fourth frame edge 114 (i.e., the back plate portion 12 is integrally connected to the above-mentioned first frame edge portion of the frame portion 11). In these embodiments, the portion of the first frame edge 111 that is not connected to the back plate portion 12, the second frame edge 112, and the portion of the third frame edge 113 that is not connected to the back plate portion 12 (i.e., the above-mentioned second frame edge portion of the frame portion 11) can be used to connect a back cover decorative surface layer 13 of the mobile terminal 400. The back cover decorative surface layer 13 may, for example, be a leather-textured decorative surface layer, a wood-textured decorative surface layer, or a cloth-textured decorative surface layer, etc., which is not specifically limited in the present application.

[0115] For another example, in some other embodiments of the present application (not shown in the drawings), the frame portion can also be in a round frame shape or a regular polygon frame shape, and the back plate portion can be integrally connected to at least a portion of the frame portion. The back cover member of these embodiments can be applied to, for example, smart terminal products such as wearable devices.

[0116] The specific material and material structure composition of the back cover body 10 are not specifically limited in the embodiments of the present application.

[0117] As shown in FIGS. 2A and 2B, in some embodiments of the present application, the back cover body 10 can adopt a composite structure layer design, and the frame portion 11 and the back plate portion 12 both include a first metal layer 102 and a second metal layer 103 connected in composite, wherein the first metal layer 102 is located on the side of the second metal layer 103 away from the accommodation cavity, and the main elements of the first metal layer 102 and the second metal layer 103 are different, and the support structure 30 is the same as the main element of the second metal layer 103.

[0118] In the embodiments of the present application, “the main elements of the first metal layer 102 and the second metal layer 103 are different” can be understood as the main metal elements of the two materials being different. The back cover body 10 is made of two metal materials with different main elements, which can have the advantages of both materials.

[0119] In the embodiments of the present application, the "support structure 30 and the main element of the second metal layer 103 are the same" can be understood as the main metal elements of the two materials are the same, and other additive elements can be the same or different. The support structure 30 and the main element of the second metal layer 103 are the same, which can reduce or even avoid the welding weakness caused by the difference in material thermal conductivity and linear expansion coefficient compared to using different main element materials.

[0120] The specific material selection of the first metal layer 102 and the second metal layer 103 is not limited. For example, in some embodiments, the material of the first metal layer 102 is titanium, titanium alloy or stainless steel, and the material of the second metal layer 103 is aluminum alloy, and the material of the support structure 30 is aluminum alloy. For example, the first metal layer 102 and the second metal layer 103 can be titanium layer and aluminum alloy layer, titanium alloy layer and aluminum alloy layer, or stainless steel layer and aluminum alloy layer, etc. The support structure 30 and the second metal layer 103 both use aluminum alloy, which can be the same system aluminum alloy or different system aluminum alloy, for example, in some embodiments, the support structure 30 and the second metal layer 103 are respectively: six-system aluminum alloy (main element is aluminum, additive elements include magnesium and silicon) and seven-system aluminum alloy (main element is aluminum, additive elements include zinc), or six-system aluminum alloy and six-system aluminum alloy, etc.

[0121] Among the above-mentioned materials, titanium has good corrosion resistance, high strength, light weight and other characteristics; titanium alloy has good corrosion resistance, high strength, good toughness and other characteristics; steel has high strength, good wear resistance, easy processing, low cost and other characteristics; aluminum alloy has low density, good mechanical properties, good processing performance, non-toxic, easy to recycle, excellent thermal conductivity and corrosion resistance, etc.

[0122] In some embodiments of the present application, the thickness of the first metal layer 102 can be designed to be smaller than the thickness of the second metal layer 103, and the hardness of the first metal layer 102 is greater than the hardness of the second metal layer 103. In this way, the back shell member 100 not only has good surface wear resistance, but also can meet the design requirements of structural strength. Designing the thickness of the second metal layer 103 to be greater than the thickness of the first metal layer 102 makes it easier to achieve reliable connection of the support structure 30 with the frame part 11 and the back plate part 12, and the support structure 30 is also more convenient to manufacture.

[0123] The specific thickness of the first metal layer 102 and the second metal layer 103 is not limited, for example, in some embodiments, the thickness of the first metal layer 102 is designed to be not greater than 0.3mm, and the thickness of the second metal layer 103 is designed to be not greater than 0.7mm, although the overall thickness of the back shell body 10 is not greater than 1mm, but the design of the support structure 30 can significantly increase the overall structural strength of the back shell member 100, so that the back shell member 100 still has good structural reliability.

[0124] In some embodiments of the present application, the side of the first metal layer 102 facing away from the second metal layer 103 can also have a surface treatment layer (not shown in the figure). The surface treatment layer can improve the wear resistance, corrosion resistance, stain resistance, or fingerprint resistance of the appearance surface of the back shell member, and can also improve the appearance effect of the back shell member, thereby making the product design more competitive. In some embodiments, the surface treatment layer can be formed by a process such as physical vapor deposition (PVD).

[0125] In some embodiments of the present application, the back shell body 10 can also not use a composite structure layer, but use a single metal layer such as an aluminum alloy layer or a stainless steel layer, etc., which is not specifically limited in the present application.

[0126] As shown in FIGS. 6A and 6B, FIG. 6A is a simplified front structural schematic diagram of a back shell member 100 according to some embodiments of the present application, and FIG. 6B is a sectional structural schematic diagram of the back shell member 100 along the B-B direction of FIG. 6A. In these embodiments, the support structure 30 is integrally connected with the inner wall of the back plate portion 12, and the frame portion 11 includes a plurality of spliced segments 110 that are spliced in a frame shape, wherein the back plate portion 12 is spliced with the plurality of spliced segments 110, and the support structure 30 is welded with the inner wall of each spliced segment 110.

[0127] The back shell member 100 of this embodiment not only can obtain similar beneficial effects as the foregoing embodiments, but also is relatively simple to process and manufacture, which is conducive to saving raw materials and reducing production costs.

[0128] As shown in FIG. 6B, the back plate portion 12 and the spliced segment 110 can be spliced in a stepped shape, that is, the splicing surface therebetween is stepped. This design has the advantages that, on the one hand, it facilitates mutual alignment of the two, which is conducive to improving assembly accuracy; on the other hand, it can reduce the entry of dust from there after assembly, thereby improving production yield; and on the other hand, it can also make the appearance of the spliced structure more beautiful.

[0129] Continuing to refer to FIGS. 6A and 6B, in some embodiments, the frame portion 11 and the back plate portion 12 both include a first metal layer 102 and a second metal layer 103 that are connected in a composite manner, wherein the support structure 30 and the second metal layer 103 of the frame portion 11 can be connected by XY-direction (Y-direction is not shown since it is perpendicular to the paper) welding through a friction stir welding process.

[0130] As shown in FIG. 6B, which also illustrates the general shape of the molten pool 116 of the friction stir welding process, it can be seen that the molten pool 116 can extend downward in the Z direction, so that the second metal layer 103 of the frame portion 11 and the second metal layer 103 of the back plate portion 12 can also be connected in the Z direction at some positions by the friction stir welding process.

[0131] In some embodiments, as shown in FIG. 6B, there is a gap 115 between the back plate portion 12 and at least one of the plurality of spliced segments 110 for the electromagnetic wave to pass through. In this way, the design of the antenna system of the mobile terminal can be facilitated. In these embodiments, the gap 115 can specifically be a gap between the first metal layer 102 of the spliced segment 110 and the discontinuous surface of the first metal layer 102 and the second metal layer 103 of the back plate portion 12. In some embodiments, the gap 115 can be filled with a decorative material, such as a plastic material, which does not affect the passage of the electromagnetic wave. In other embodiments, the gap 115 can also not be filled.

[0132] As shown in FIG. 6C, which is a schematic view of the cross-sectional structure of the rear shell member 100 along the B-B direction of FIG. 6A according to some other embodiments of the present application, these embodiments differ from the embodiments shown in FIG. 6B in that the gap 115 for the electromagnetic wave to pass through is a gap between the first metal layer 102 of the spliced segment 110 and the discontinuous surface of the first metal layer 102 of the back plate portion 12. Similarly, the gap 115 can be filled with a decorative material, which does not affect the passage of the electromagnetic wave, or can not be filled.

[0133] The rear shell member 100 of the above-described embodiments of the present application can be implemented by various manufacturing process schemes.

[0134] As shown in FIGS. 7A and 7B, wherein FIG. 7A is a schematic flow diagram of a manufacturing method 700 of the rear shell member 100 according to some embodiments of the present application, and FIG. 7B is a schematic view of the manufacturing process of the rear shell member 100 in these embodiments. The manufacturing method 700 can include the following steps S701 to S703.

[0135] At step S701, a rear shell body 10 is provided, which includes a frame portion 11 and a back plate portion 12 that are integrally connected and define a receiving cavity 101.

[0136] At step S702, a middle plate 300a is provided, and the middle plate 300a is welded to the inner wall of the frame portion 11 and to the inner wall of the back plate portion 12.

[0137] At step S703, part of the middle plate 300a is removed, and at least part of the welding structure between the middle plate 300a and the frame portion 11 and at least part of the welding structure between the middle plate 300a and the back plate portion 12 are retained to obtain the support structure 30, wherein the support structure 30 is welded to the inner wall of the frame portion 11 and the inner wall of the back plate portion 12, and the support structure 30 and the whole of the back shell body 10 define at least one positioning recess 31 inside the back shell member 100 (the structure of the back shell body 10 in FIG. 7B is a simplified schematic drawing, and the actual structure of the back shell body 10 is not limited to this structure).

[0138] By using the manufacturing method 700 of the above embodiments, the back shell member 100 shown in FIG. 1 can be manufactured, which is applied to a mobile terminal, can provide reliable positioning for electronic components of the mobile terminal, thereby reducing the assembly design difficulty of the electronic components, improving the assembly reliability of the electronic components, and further improving the product structure reliability of the mobile terminal; since the support structure 30 is welded to the inner wall of the frame portion 11 and the inner wall of the back plate portion 12, that is, the support structure 30 is connected to the back shell body 10 in the XY direction and the Z direction, the structural strength of the back shell member 100 can be improved, thereby facilitating the improvement of the product structure reliability of the mobile terminal; in addition, since the support structure 30 is obtained by removing part of the middle plate 300a, the manufacturing process is relatively simple, the manufacturing cost is relatively low, and accurate structure parameters can be easily obtained, thereby further improving the assembly reliability of the electronic components in the mobile terminal.

[0139] Referring to FIG. 7B, in some embodiments of the present application, at step S701, a back shell body 10 is provided, which can include the following sub-step S7011 and sub-step S7012.

[0140] At sub-step S7011, a composite plate 410 is provided, which includes a first metal layer 102 and a second metal layer 103 that are different in main elements.

[0141] In some embodiments, the first metal layer 102 and the second metal layer 103 can be sequentially formed into the composite plate 410 through surface treatment, lamination, roll bonding and diffusion processes, wherein the surface treatment process can include cleaning the surface and removing the surface oxide layer, the roll bonding process can include hot rolling and cold rolling, and the diffusion process can include diffusion annealing.

[0142] In some embodiments, the first metal layer 102 and the second metal layer 103 can also be sequentially formed into the composite plate 410 through surface treatment, lamination and explosive welding processes, wherein explosive welding is a method of using the impact force generated by the explosion of explosives to cause the workpieces to collide rapidly to achieve welding.

[0143] The material selection of the first metal layer 102 and the second metal layer 103 can refer to the foregoing description about the embodiment of the rear shell member 100, which will not be repeated here.

[0144] In sub-step S7012, the composite sheet 410 is formed into the rear shell body 10 with the accommodating cavity 101, wherein the first metal layer 102 is located on the side of the second metal layer 103 facing away from the accommodating cavity 101. In this sub-step S7012, the composite sheet 410 can be specifically formed into the rear shell body 10 with the accommodating cavity 101 by a stamping process.

[0145] Continuing to refer to FIG. 7B, in some embodiments of the present application, in step S702, before the middle plate 300a is welded with the rear shell body 10, the middle plate 300a can be pre-fixed in the accommodating cavity 101 of the rear shell body 10 by using a clamp (not shown in the figure) or by spot gluing (not shown in the figure) and the like.

[0146] Continuing to refer to FIG. 7B, in some embodiments of the present application, in step S702, when the middle plate 300a is welded with the rear shell body 10, the middle plate 300a can be first welded with the inner wall of the frame portion 11 along the first preset welding trajectory line 301 by a friction stir welding process, and then the middle plate 300a can be welded with the inner wall of the back plate portion 12 along the second preset welding trajectory line 302 by a friction stir welding process, or the middle plate 300a can be first welded with the inner wall of the back plate portion 12 along the second preset welding trajectory line 302 by a friction stir welding process, and then the middle plate 300a can be welded with the inner wall of the frame portion 11 along the first preset welding trajectory line 301 by a friction stir welding process. The friction stir welding process can obtain a weld with lower defects, and almost no welding smoke and spatter, and almost no ultraviolet and electromagnetic radiation, and has strong compatibility with welding parameters and welding materials.

[0147] The first preset welding trajectory line 301 and the second preset welding trajectory line 302 can be designed according to the specific structural size parameters of the support structure 30, and in the figure are only for simplification and do not represent the actual design. For example, in some embodiments, the first preset welding trajectory line 301 can be in a closed shape, or in a line segment shape, or in a combination shape of multiple line types; the second preset welding trajectory line 302 can be in a closed shape, or in a line segment shape, or in a combination shape of multiple line types.

[0148] In some embodiments of the present application, the middle plate 300a can also be welded with the frame portion 11 and the back plate portion 12 by other welding processes, which are not limited in the embodiments of the present application.

[0149] In some embodiments of the present application, the removing of the partial material of the middle plate 300a in step S703 can be achieved by a computer numerical control (CNC) machining. CNC is a program-controlled automatic machine tool, which has the characteristics of high machining precision, high efficiency, high reliability, etc. By using CNC, the support structure 30 with high dimensional accuracy can be machined.

[0150] In step S703, during the process of removing the partial material of the middle plate 300a, at least part of the welding structure between the middle plate 300a and the frame part 11, and at least part of the welding structure between the middle plate 300a and the back plate part 12 are retained, so that the obtained support structure 30 is welded with the inner wall of the frame part 11 and the inner wall of the back plate part 12, that is, the support structure 30 is connected with the rear shell body 10 in XY direction and Z direction, so that the structural strength of the manufactured rear shell member 100 is high.

[0151] In some embodiments of the present application, after the above step S703 is completed, subsequent processing of the rear shell member 100 can be continued by other processes, including but not limited to: processing some hole and groove structures of the rear shell member 100 by CNC process, such as camera module mounting hole, flash mounting hole, sensor mounting hole, USB hole, etc.; processing other structures of the rear shell member 100 by nano molding technology (NMT) process; forming a surface treatment layer on the outer surface of the rear shell member 100 by PVD process, such as a decorative surface layer.

[0152] As shown in FIGS. 8A and 8B, FIG. 8A is a flow diagram of a manufacturing method 800 of a rear shell member 100 according to some embodiments of the present application, and FIG. 8B is a schematic diagram of the manufacturing process of the rear shell member 100 in these embodiments. The manufacturing method 800 can include the following steps S801 to S805.

[0153] In step S801, a plate member 420 is provided.

[0154] In step S802, a part of the thickness of the peripheral region of the plate member 420 is removed to obtain a first part 501 and a second part 502 with different thicknesses, wherein the first part 501 surrounds the second part 502, and the thickness of the first part 501 is smaller than the thickness of the second part 502.

[0155] In step S803, the first part 501 is folded towards the second part 502 and adhered to the second part 502.

[0156] In step S804, the side walls of the first part 501 and the second part 502 are welded.

[0157] At step S805, part of the material of the second part 502 is removed and at least part of the welding structure of the first part 501 and the second part 502 is retained to obtain the rear shell body 10 and the support structure 30, wherein the rear shell body 10 comprises the frame part 11 and the back plate part 12 which are integrally connected and define the accommodating cavity 101, and the support structure 30 is located in the accommodating cavity 101 and is welded with the inner wall of the frame part 11 and integrally connected with the inner wall of the back plate part 12, and the support structure 30 and the rear shell body 10 integrally define at least one positioning recess 31 on the inner side of the rear shell member 100.

[0158] By using the manufacturing method 800 of the above-described embodiments of the present application, the rear shell member 100 shown in FIG. 1 can be manufactured, which is applied to a mobile terminal and can provide reliable positioning for electronic components of the mobile terminal, thereby reducing the assembly design difficulty of the electronic components, improving the assembly reliability of the electronic components, and further improving the product structure reliability of the mobile terminal. Since the support structure 30 is welded with the inner wall of the frame part 11 and integrally connected with the inner wall of the back plate part 12, that is, the support structure 30 is connected with the rear shell body 10 in the XY direction and the Z direction, the structural strength of the rear shell member 100 can be improved, thereby being conducive to improving the product structure reliability of the mobile terminal. In addition, since the support structure 30 is obtained by removing part of the material of the second part 502, the manufacturing process is relatively simple and the manufacturing cost is relatively low, and accurate structure parameters can be easily obtained, thereby further improving the assembly reliability of the electronic components in the mobile terminal.

[0159] In some embodiments of the present application, referring to FIG. 8B, in step S801, a plate member 420 is provided, which can include: providing a composite plate 410, wherein the composite plate 410 comprises a first metal layer 102 and a second metal layer 103 which are different in main elements. The first metal layer 102 and the second metal layer 103 can be sequentially formed into the composite plate 410 through processes such as surface treatment, lamination, pack rolling and diffusion. The material selection of the first metal layer 102 and the second metal layer 103 can refer to the description of the above-described embodiments of the rear shell member 100, which will not be repeated here.

[0160] Referring to FIG. 8B, in step S802, removing the partial thickness of the material of the peripheral region of the sheet member 420 can include removing the partial thickness of the material of the peripheral region of the second metal layer 103. That is, after step S802 is completed, the first part 501 and the second part 502 with different thicknesses can be obtained, the first part 501 surrounds the second part 502, and the first part 501 and the second part 502 both include the first metal layer 102 and the second metal layer 103, but the thickness of the second metal layer 103 of the first part 501 is less than the thickness of the second metal layer 103 of the second part 502, so that the overall thickness of the first part 501 is less than the overall thickness of the second part 502.

[0161] In some embodiments of the present application, in step S803, folding the first part 501 towards the second part 502 and attaching the first part 501 to the second part 502 can be achieved by sheet stretching and bending forming by a stamping device.

[0162] Continuing to refer to FIG. 8B, in some embodiments of the present application, the manufacturing method 800 can further include, after step S803 and before step S804, removing part of the material of the first part 501 and / or the second part 502 to make the first part 501 flush with the second part 502. Adding this step can on the one hand appropriately reduce the dimensional accuracy requirement of providing the sheet member 420 in step S801, the material processing accuracy requirement of removing the material of the peripheral region of the sheet member 420 in step S802, or the forming accuracy requirement of stretching and bending in step S803, and on the other hand, a higher-precision intermediate prefabricated part can also be obtained.

[0163] Continuing to refer to FIG. 8B, in some embodiments of the present application, in step S804, when welding the side walls of the first part 501 and the second part 502, the side walls of the first part 501 and the second part 502 can be welded along a preset welding trajectory line 503 by a friction stir welding process. In some embodiments, the preset welding trajectory line 503 can have a closed shape, so that the first part 501 and the second part 502 are welded at all places around the circumference. In some embodiments, the preset welding trajectory line can also have a line segment shape, so that the first part 501 and the second part 502 are only welded in the area required by the design.

[0164] In some embodiments of the present application, the first part 501 and the second part 502 can also be welded by other welding processes, which are not specifically limited in the embodiments of the present application.

[0165] In some embodiments of the present application, removing the partial thickness of the material of the peripheral region of the sheet member 420, removing part of the material of the first part 501 and / or the second part 502 can be achieved by CNC machining.

[0166] In step S805, at least a part of the welding structure between the first part 501 and the second part 502 is retained in the process of removing part of the material of the second part 502, so that the obtained support structure 30 is welded to the inner wall of the frame part 11, and since the support structure 30 is integrally connected to the inner wall of the back plate part 12, the support structure 30 is connected to the back shell body 10 in the XY direction and the Z direction, so that the structural strength of the obtained back shell member 100 is high.

[0167] After the above step S805 is completed, the back shell member 100 can also be further processed by other processes, which include but are not limited to: processing some hole and groove structures of the back shell member 100 such as camera module mounting holes, flash mounting holes, sensor mounting holes, USB holes, etc. by CNC process; processing other structures of the back shell member 100 by NMT process; forming a surface treatment layer such as a decorative surface layer on the outer side surface of the back shell member 100 by PVD process.

[0168] As shown in FIGS. 9A and 9B, wherein FIG. 9A is a flowchart of a manufacturing method 900 of a back shell member 100 according to some embodiments of the present application, and FIG. 9B is a schematic diagram of the manufacturing process of the back shell member 100 in these embodiments. The manufacturing method 900 can include the following steps S901 to S903.

[0169] In step S901, a middle plate 300b and a plurality of splicing segments 110 are provided.

[0170] In step S902, the plurality of splicing segments 110 are spliced into the frame part 11, and the middle plate 300b is welded to the inner wall of the frame part 11.

[0171] In step S903, part of the material of the middle plate 300b is removed and at least a part of the welding structure between the middle plate 300b and the frame part 11 is retained, to obtain a back shell body 10 and a support structure 30, wherein the back shell body 10 includes a back plate part 12 and a frame part 11 defining a receiving cavity 101, the support structure 30 is located in the receiving cavity 101 and is welded to the inner wall of the frame part 11 and integrally connected to the inner wall of the back plate part 12, and the support structure 30 and the whole of the back shell body 10 define at least one positioning recess 31 on the inner side of the back shell member 100.

[0172] As shown in FIG. 9B, in some embodiments of the present application, at step S901, the middle plate 300b and the plurality of splicing segments 110 can be obtained by cutting and bending processing or CNC processing of the composite plate 410. For example, in some embodiments, the middle plate 300b and the plurality of strips can be obtained after cutting the composite plate 410, and the plurality of splicing segments 110 can be obtained by bending the plurality of strips. As shown in FIG. 9B, the composite plate 410 can include the first metal layer 102 and the second metal layer 103 which are different in main element. The material selection and manufacturing process of the composite plate 410 are as described in the foregoing embodiments, which will not be repeated here. In some embodiments of the present application, the splicing surface of the middle plate 300b and the plurality of splicing segments 110 can be processed into a stepped shape. In this way, not only is it convenient to align with each other, which is conducive to improving the assembly accuracy, but also it can reduce the entry of dust from this place after assembly, thereby improving the production yield; in addition, it can also make the appearance of the spliced structure more beautiful.

[0173] In some embodiments of the present application, at step S902, before the middle plate 300b and the plurality of splicing segments 110 are welded, the middle plate 300b and the plurality of splicing segments 110 can be pre-fixed by using a clamp (not shown in the figure) or by applying spot glue (not shown in the figure) and the like.

[0174] In some embodiments of the present application, at step S902, welding the middle plate 300b and the inner wall of the frame part 11 can include: welding the middle plate 300b and the inner wall of the frame part 11 along a preset welding trajectory line 503 by a friction stir welding process. In some embodiments, the preset welding trajectory line 503 can be in a closed shape, so that the middle plate 300b and the frame part 11 are welded at each place around the circumference. In some embodiments, the preset welding trajectory line can also be in a line segment shape, so that the middle plate 300b and the frame part 11 are only welded in the local area required by the design.

[0175] Using the manufacturing method 900 of the above embodiments of the present application, the back shell member 100 shown in FIG. 6A can be manufactured, which is applied to a mobile terminal and can provide reliable limiting for electronic components of the mobile terminal, thereby reducing the assembly design difficulty of the electronic components, improving the assembly reliability thereof, and further improving the product structure reliability of the mobile terminal; since the support structure 30 is welded with the inner wall of the frame part 11 and integrally connected with the inner wall of the back plate part 12, that is, the support structure 30 is connected with the back shell body 10 in the XY direction and the Z direction, so that the structural strength of the back shell member 100 can be improved, thereby being conducive to improving the product structure reliability of the mobile terminal; in addition, since the middle plate 300b and the plurality of splicing segments 110 can be obtained by cutting and bending processing or CNC processing of the plate piece, it is convenient for processing and manufacturing of parts, which is conducive to saving raw materials and reducing production cost.

[0176] After the step S903 is completed, the rear shell member 100 can also be further processed by other processes, including but not limited to: processing some hole and groove structures of the rear shell member 100, such as the camera module mounting hole, the flash mounting hole, the sensor mounting hole, the USB hole, etc. by the CNC process; processing other structures of the rear shell member 100 by the NMT process; forming a surface treatment layer, such as a decorative surface layer, on the outer side surface of the rear shell member 100 by the PVD process.

[0177] As shown in FIG. 10, which is a flow diagram of a manufacturing method 1000 of a rear shell member 100 according to some embodiments of the present application, the manufacturing method can include the following steps S1001 to S1002.

[0178] In step S1001, a rear shell body is provided, which includes a frame portion and a back plate portion, and the frame portion and the back plate portion are integrally connected and define a receiving cavity.

[0179] In step S1002, a support structure is provided, the support structure is welded with the inner wall of the frame portion, and the support structure is welded with the inner wall of the back plate portion, wherein the support structure is a die casting, and the support structure and the whole of the rear shell body define at least one positioning recess on the inner side of the rear shell member.

[0180] Regarding the manufacturing of the rear shell body in step S1001, reference can be made to the foregoing embodiments, which will not be repeated here.

[0181] In some embodiments, the rear shell body can include a first metal layer and a second metal layer, wherein the first metal layer is located on the side of the second metal layer away from the receiving cavity. The second metal layer and the support structure can be selected from the same or different series of aluminum alloys, wherein the materials that can be selected for the support structure include but are not limited to die-cast aluminum alloys (material model numbers such as ADC10, ADC12, or YZAlSi12, etc.) or high-thermal-conductivity die-cast aluminum alloys (material model numbers such as DMS1, DMS3, DMS5, DMS6, or LZTH-HTC01, etc.).

[0182] The support structure can be formed into its basic structure by die casting or semi-solid die casting process. Die casting is a kind of precision casting method that uses high pressure to force molten metal into a metal mold with complex shape. Semi-solid die casting is a process that stirs the liquid metal intensively during its solidification process, so that the ordinary casting network skeleton of dendritic crystals is broken and forms a dispersed granular structure, thereby producing semi-solid metal liquid, which is then die cast into a blank or a casting. By die casting or semi-solid die casting process, the basic member of the support structure can be directly formed, with high dimensional accuracy, which can reduce or even avoid secondary machining process, thereby having high production efficiency.

[0183] The rear shell member 100 shown in FIG. 1 can be manufactured by using the manufacturing method 1000 of the above-mentioned embodiments of the present application, and can be applied to a mobile terminal. The rear shell member 100 can provide reliable positioning for electronic components of the mobile terminal, thereby reducing the assembly design difficulty of the electronic components, improving the assembly reliability of the electronic components, and further improving the product structure reliability of the mobile terminal. Since the support structure is welded to the inner wall of the frame portion and the inner wall of the back plate portion, that is, the support structure is connected to the rear shell body in the XY direction and the Z direction, the structural strength of the rear shell member can be improved, thereby facilitating the improvement of the product structure reliability of the mobile terminal. In addition, since the support structure is a die casting, the production efficiency is high, and accurate structure parameters can be easily obtained, thereby facilitating the further improvement of the assembly reliability of the electronic components in the mobile terminal.

[0184] The embodiments of the present application also provide a mobile terminal. As shown in FIG. 11, it is a cross-sectional structure schematic diagram of a mobile terminal 400 according to some embodiments of the present application. The main structure of the mobile terminal 400 can include a rear shell member 100, a main board 41, a battery 43, and a display screen 105. The rear shell member 100 can be a rear shell member 100 designed according to the above-mentioned embodiments, or a rear shell member 100 manufactured according to the manufacturing method of the above-mentioned embodiments, wherein the support structure 30 and the rear shell body 10 together define at least two positioning recesses 31 inside the rear shell member 100, and the at least two positioning recesses 31 can include a main board positioning recess 311 and a battery positioning recess 312. The main board 41 and the battery 43 are correspondingly positioned in the main board positioning recess 311 and the battery positioning recess 312. The display screen 105 is located in front of the main board 41 and the battery 43 and is connected to the frame portion 11.

[0185] In the embodiments of the present application, the specific product types of the mobile terminal 400 can include but are not limited to mobile phones, tablet computers, personal computers, wearable devices, etc. The main board 41, also known as the motherboard or system board, is one of the core components inside the mobile terminal 400, and can mainly include a processor, a memory and a storage module, a communication module, etc.

[0186] As shown in FIG. 11, in some embodiments, the mobile terminal 400 can also include a sub-board 42, a camera module, a flash, a laser focusing sensor, an ambient light sensor, a speaker, an earpiece, a microphone, a wireless charging module, a chip card, or a motor (these electronic components are not shown in the figure), etc. The sub-board 42 is mainly used to connect the main board 41 and some external accessories in the mobile terminal 400.

[0187] By designing the support structure 30 accordingly, the support structure 30 and the whole of the rear shell body 10 can define a positioning recess 31 matching the plurality of electronic components 104, so that more flexible and rich design options can be provided for the assembly of the electronic components 104 of the mobile terminal 400.

[0188] According to the mobile terminal 400 of the embodiments of the present application, on the one hand, the positioning recess 31 of the rear shell member 100 can provide reliable positioning for the electronic components 104 of the mobile terminal 400, so as to reduce the assembly design difficulty of the electronic components 104, improve the assembly reliability thereof, and further improve the product structure reliability of the mobile terminal 400. On the other hand, since the support structure 30 of the rear shell member 100 is welded with the inner wall of the frame portion 11 and welded or integrally connected with the inner wall of the back plate portion 12, that is, the support structure 30 is connected with the rear shell body 10 in the XY direction and the Z direction, the overall structural strength of the rear shell member 100 is high, and the product structure reliability of the mobile terminal 400 is high. On the other hand, the processing and manufacturing of the rear shell member 100 can be realized by various process schemes (as described in the foregoing embodiments), so as to facilitate the improvement of the manufacturing precision and the reduction of the manufacturing cost of the mobile terminal 400.

[0189] Referring to FIG. 1, in some embodiments of the present application, the frame portion 11 of the rear shell member 100 of the mobile terminal 400 can be substantially a rounded rectangular frame shape, which includes a first frame edge 111, a second frame edge 112, a third frame edge 113 and a fourth frame edge 114 connected in sequence, wherein the back plate portion 12 is integrally connected with the first frame edge 111, the second frame edge 112, the third frame edge 113 and the fourth frame edge 114.

[0190] Referring to FIG. 5, in some other embodiments of the present application, the frame portion 11 of the mobile terminal 400 can be substantially a rounded rectangular frame shape, which includes a first frame edge 111, a second frame edge 112, a third frame edge 113 and a fourth frame edge 114 connected in sequence, wherein the back plate portion 12 is integrally connected with a part of the first frame edge 111, a part of the third frame edge 113 and the fourth frame edge 114 (that is, the back plate portion 12 is integrally connected with the above-mentioned first frame edge portion of the frame portion 11). In these embodiments, the part of the first frame edge 111 not connected with the back plate portion 12, the second frame edge 112, and the part of the third frame edge 113 not connected with the back plate portion 12 (that is, the above-mentioned second frame edge portion of the frame portion 11) can be used to connect the rear shell decorative surface layer 13 of the mobile terminal 400.

[0191] The rear case decorative surface 13 can be, for example, a leather-like decorative surface, a wood-like decorative surface, or a cloth-like decorative surface, and the like, and the present application is not limited thereto. In these embodiments, the outer side surface of the portion where the bezel portion 11 is connected to the back plate portion 12 and the outer side surface of the portion where the bezel portion 11 is connected to the rear case decorative surface 13 can have plating layers with consistent or inconsistent appearance patterns, thereby making the rear case of the mobile terminal 400 more coordinated and aesthetically pleasing.

[0192] The above merely provides a specific implementation of the present application, but the scope of protection of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical scope disclosed by the present application, which should be encompassed within the scope of protection of the present application. Therefore, the scope of protection of the present application should be subject to the scope of protection of the claims.

Claims

1. A back cover member (100) for a mobile terminal, characterized in that, The back shell body (10) comprises a frame part (11) and a back plate part (12), wherein the frame part (11) and the back plate part (12) define a receiving cavity (101); and A support structure (30) is arranged in the receiving cavity (101), wherein the support structure (30) is welded with the inner wall of the frame part (11), the support structure (30) is welded or integrally connected with the inner wall of the back plate part (12), and the whole of the support structure (30) and the back shell body (10) defines at least one positioning recess (31) on the inner side of the back shell member (100). The support structure comprises:

2. The rear housing member (100) according to claim 1, characterized in that A first protruding structure (32) welded with the inner wall of the frame part (11); and A second protruding structure (33) welded or integrally connected with the inner wall of the back plate part (12).

3. The back shell member (100) according to claim 2, wherein The first protruding structure (32) and the inner wall of the back plate part (12) are not connected with each other; or The first protruding structure (32) and the inner wall of the back plate part (12) are integrally connected; or At least a part of the first protruding structure (32) is welded with the inner wall of the back plate part (12).

4. The back shell member (100) according to claim 2 or 3, wherein At least a part of the first protruding structure (32) is in a strip shape; At least a part of the second protruding structure (33) is in a strip shape, or at least a part of the second protruding structure (33) is in a boss shape.

5. The back shell member (100) according to any one of claims 1 to 4, wherein The whole of the support structure (30) and the back shell body (10) defines a plurality of positioning recesses (31) on the inner side of the back shell member (100), and among the plurality of positioning recesses (31), The normal projections of at least two positioning recesses (31) on the back plate part (12) do not overlap with each other; and / or At least two positioning recesses (31) are arranged in a direction orthogonal to the back plate part (12), and the normal projection of one of the at least two positioning recesses (31) on the back plate part (12) overlaps with the normal projection of the other positioning recess (31) on the back plate part (12).

6. The back shell member (100) according to any one of claims 1 to 5, wherein The support structure (30) is integrally connected with the inner wall of the back plate part (12); The frame part (11) comprises a plurality of spliced segments (110) spliced in a frame shape, wherein the back plate part (12) is spliced with the plurality of spliced segments (110), and the support structure (30) is welded with the inner wall of each spliced segment (110) of the plurality of spliced segments (110).

7. The back shell member (100) according to claim 6, wherein There is a gap (115) for electromagnetic waves to pass between the back plate part (12) and at least one spliced segment (110) of the plurality of spliced segments (110). ​ 8. The rear shell member (100) according to any one of claims 1 to 7, characterized in that, the back plate portion (12) is connected with each part of the perimeter of the frame portion (11); or the frame portion (11) comprises a first frame edge portion and a second frame edge portion, wherein the back plate portion (12) is connected with the first frame edge portion and is not connected with the second frame edge portion, and the second frame edge portion is used for connecting a rear shell decoration surface layer of the mobile terminal.

9. The rear shell member (100) according to any one of claims 1 to 8, characterized in that, the at least one positioning recess (31) is used for limiting at least one electronic component (104) of the mobile terminal, and the at least one electronic component (104) comprises one or more of a main board, a sub-board, a camera module, a flash, a laser focusing sensor, an ambient light sensor, a loudspeaker, an earpiece, a microphone, a wireless charging module, a chip card, a motor, or a battery.

10. The rear shell member (100) according to any one of claims 1 to 9, characterized in that, the frame portion (11) and the back plate portion (12) each comprise a first metal layer (102) and a second metal layer (103) connected in a composite manner, wherein the first metal layer (102) is located on a side of the second metal layer (103) facing away from the accommodation cavity (101), and the main elements of the first metal layer (102) and the second metal layer (103) are different, and the support structure (30) is the same as the main element of the second metal layer (103).

11. The rear shell member (100) according to claim 10, characterized in that, the thickness of the first metal layer (102) is less than the thickness of the second metal layer (103), and the hardness of the first metal layer (102) is greater than the hardness of the second metal layer (103); and / or a side of the first metal layer (102) facing away from the second metal layer (103) has a surface treatment layer.

12. The rear shell member (100) according to claim 10 or 11, characterized in that, the material of the first metal layer (102) comprises titanium, a titanium alloy, or stainless steel; the material of the second metal layer (103) comprises an aluminum alloy; the material of the support structure (30) comprises an aluminum alloy.

13. A method of manufacturing a rear housing member (100) for a mobile terminal, characterized by, including: providing a rear shell body (10) comprising a frame portion (11) and a back plate portion (12), wherein the frame portion (11) and the back plate portion (12) are integrally connected and define an accommodation cavity (101); providing a middle plate (300a) welded with an inner wall of the frame portion (11), and the middle plate (300a) is welded with an inner wall of the back plate portion (12); and Remove part of the material of the middle plate (300a) and retain at least part of the welding structure of the middle plate (300a) and the frame part (11), and at least part of the welding structure of the middle plate (300a) and the back plate part (12), to obtain a support structure (30), wherein the support structure (30) is welded with the inner wall of the frame part (11) and the inner wall of the back plate part (12), and the support structure (30) and the whole of the rear shell body (10) define at least one positioning recess (31) inside the rear shell member (100).

14. The manufacturing method of claim 13, wherein, Welding the middle plate (300a) and the inner wall of the frame part (11) includes welding the middle plate (300a) and the inner wall of the frame part (11) by friction stir welding along a first preset welding trajectory line (301); and / or Welding the middle plate (300a) and the inner wall of the back plate part (12) includes welding the middle plate (300a) and the inner wall of the back plate part (12) by friction stir welding along a second preset welding trajectory line (302).

15. The production method according to claim 13 or 14, characterized in that, The rear shell body is provided, including: Providing a composite plate (410) including a first metal layer (102) and a second metal layer (103) different in main elements; and Forming the composite plate (410) into a rear shell body (10) having a receiving cavity (101), wherein the first metal layer (102) is located on the side of the second metal layer (103) away from the receiving cavity (101).

16. A method of manufacturing a rear housing member (100) for a mobile terminal, characterized by, Including: Providing a plate piece (420); Removing part of the thickness of the peripheral region of the plate piece (420) to obtain a first part (501) and a second part (502) different in thickness, wherein the first part (501) surrounds the second part (502), and the thickness of the first part (501) is less than the thickness of the second part (502); Folding the first part (501) towards the second part (502) and abutting the second part (502); Welding the first part (501) and the side wall of the second part (502); and Removing part of the material of the second part (502) and retaining at least part of the welding structure of the first part (501) and the second part (502) to obtain a rear shell body (10) and a support structure (30), wherein, The rear shell body (10) includes a frame part (11) and a back plate part (12) integrally connected and defining a receiving cavity (101), the support structure (30) is located in the receiving cavity (101) and is welded with the inner wall of the frame part (11) and integrally connected with the inner wall of the back plate part (12), the support structure (30) and the whole of the rear shell body (10) define at least one positioning recess (31) inside the rear shell member (100).

17. The method of manufacturing according to claim 16, wherein, Also including: After the first part (501) is folded towards the second part (502) and adheres to the second part (502), before the first part (501) and the side wall of the second part (502) are welded, part of the material of the first part (501) and / or the second part (502) is removed to make the first part (501) flush with the second part (502).

18. The method of manufacturing according to claim 16 or 17, wherein, Welding the first part (501) and the side wall of the second part (502) includes: Welding the first part (501) and the side wall of the second part (502) by a friction stir welding process along a preset welding trajectory (503).

19. The manufacturing method of any one of claims 16-18, wherein The providing of the plate member (420) includes providing a composite plate (410), the composite plate (410) including a first metal layer (102) and a second metal layer (103) different in main element; The removing of the part of the thickness of the material of the peripheral region of the plate member (420) includes removing the part of the thickness of the material of the peripheral region of the second metal layer (103).

20. A method for manufacturing a rear shell component (100) for a mobile terminal, characterized in that, Including: Providing a middle plate (300b) and a plurality of splicing segments (110); Splicing the plurality of splicing segments (110) into a frame portion (11), and welding the middle plate (300b) and an inner wall of the frame portion (11); and Removing part of the material of the middle plate (300b) and retaining at least part of the welding structure of the middle plate (300b) and the frame portion (11) to obtain a rear shell body (10) and a support structure (30), wherein The rear shell body (10) includes a back plate portion (12) and the frame portion (11) defining a receiving cavity (101), the support structure (30) is located in the receiving cavity (101) and is welded with the inner wall of the frame portion (11) and integrally connected with the inner wall of the back plate portion (12), and the support structure (30) and the whole of the rear shell body (10) define at least one positioning recess (31) inside the rear shell member (100).

21. The method of manufacturing according to claim 20, wherein, Welding the middle plate (300b) and the inner wall of the frame portion (11) includes: Welding the middle plate (300b) and the inner wall of the frame portion (11) by a friction stir welding process along a preset welding trajectory (503).

22. A method of fabricating a back case member for a mobile terminal, the method comprising: providing a first material layer; providing a second material layer; and joining the first material layer and the second material layer to form the back case member. Including: Providing a rear shell body, the rear shell body including a frame portion and a back plate portion, wherein the frame portion and the back plate portion are integrally connected and define a receiving cavity; and Providing a support structure, welding the support structure and an inner wall of the frame portion, and welding the support structure and an inner wall of the back plate portion, wherein the support structure is a die casting, and the support structure and the whole of the rear shell body define at least one positioning recess inside the rear shell member.

23. The manufacturing method of claim 22, wherein Welding the support structure with the inner wall of the frame portion includes: welding the support structure with the inner wall of the frame portion along a first preset welding track line by a friction stir welding process; and / or Welding the support structure with the inner wall of the back plate portion includes: welding the support structure with the inner wall of the back plate portion along a second preset welding track line by a friction stir welding process.

24. A mobile terminal (400), characterized by Comprise: A rear shell member (100), the rear shell member (100) is the rear shell member (100) according to any one of claims 1 to 12, or the rear shell member (100) is the rear shell member (100) prepared according to the manufacturing method of any one of claims 13 to 23, wherein the support structure (30) and the whole of the rear shell body (10) define at least two positioning recesses (31) on the inner side of the rear shell member (100), the at least two positioning recesses (31) include a mainboard positioning recess (311) and a battery positioning recess (312); A mainboard (41) and a battery (43) are correspondingly positioned in the mainboard positioning recess (311) and the battery positioning recess (312); And A display screen (105) is located on the front side of the mainboard (41) and the battery (43) and is connected with the frame portion (11).

Images