CN118921899A - Shell, shell manufacturing method and electronic equipment - Google Patents

Abstract

The present application provides a shell, a shell manufacturing method and an electronic device. The shell includes a middle plate and a frame, and the middle plate includes a first surface and a second surface arranged opposite to the first surface. The middle plate and the frame are integrally formed, and the frame is arranged at the edge of the first surface. The frame includes an inner side surface, and a side etching portion is formed at the connection between the inner side surface and the first surface. The present invention processes the middle plate by an etching method to achieve partial or complete thinning of the middle plate, thereby achieving lightweight and thin electronic equipment.

Description

Housing, housing manufacturing method and electronic device

Technical Field

The present application relates to the technical field of electronic device manufacturing, and in particular to a housing, a housing manufacturing method, and an electronic device.

Background Art

People's demand for the portability and reliability of electronic devices such as mobile phones and tablets is constantly increasing, which is driving electronic devices to gradually develop towards thinness and lightness. Therefore, the shells of electronic devices such as mobile phones, such as back covers and shells, as the main bearing and protection components, not only need sufficient structural strength, but also need to reduce their own thickness and weight, thereby reducing the thickness and weight of the entire device. In particular, reducing the thickness of the shell can save the internal space of the electronic device. How to reduce the thickness of the shell while meeting the structural strength requirements of the shell is a technical problem to be solved in the field of electronic equipment manufacturing technology.

Summary of the invention

The present application provides a housing, a housing manufacturing method and an electronic device, which are used to reduce the overall thickness of the electronic device and ensure that the housing has sufficient rigidity performance.

In a first aspect, the present application provides a housing, the housing comprising a middle plate and a frame, the middle plate comprising a first surface and a second surface disposed opposite to the first surface, the middle plate and the frame being integrally formed, and the frame being disposed at an edge of the first surface. The first surface has a grain boundary.

The one-piece structure of the shell solves the technical problems of flatness, waterproofness and assembly precision stability in the existing split shell (part of the middle plate is split from the middle plate corresponding to the battery compartment position, or the middle plate is split from the frame); moreover, the first surface has a grain boundary, which is a surface formed by etching the aluminum alloy material. The etching process reduces the thickness of the middle plate and does not generate stress on the middle plate. Compared with CNC processing, a thinner middle plate can be processed, thereby increasing the internal space of the shell or reducing the thickness of the shell.

In one embodiment, the roughness of the first surface is greater than or equal to 0.5.

In one embodiment, the frame includes an inner side surface, and an undercut portion is formed at a connection between the inner side surface and the first surface.

In one embodiment, the thickness of the middle plate is greater than or equal to 0.2 mm and less than or equal to 0.3 mm. The thickness of the middle plate is processed by an etching process, which avoids the generation of stress on the middle plate and affects its strength and deformation compared to CNC processing; and etching can achieve a thinner size of the middle plate compared to CNC processing.

In one embodiment, the shell is made of 6013 aluminum alloy or 7075 aluminum alloy, and the thickness of the middle plate is 0.25 mm.

In one embodiment, the shell is made of a particle-reinforced aluminum-based composite material, and the thickness of the middle plate is 0.2 mm.

In one embodiment, the surface of the undercut portion has a grain boundary.

In one embodiment, the undercut portion is a groove recessed on the inner side surface and the first surface, and along the width direction of the middle plate, the cross-section of the groove is rectangular, arc-shaped or trapezoidal.

In one embodiment, the side erosion portion is a protrusion protruding from the first surface and connected to the inner side surface, and along the width direction of the middle plate, the cross-section of the protrusion is rectangular or an inverted trapezoid; or, the protrusion includes a plane facing away from the first surface and an arc-shaped surface connected to the first surface and concave toward the middle plate.

In a second aspect, the present application further provides a method for manufacturing a housing, the method comprising:

A shell substrate is provided, wherein the shell substrate comprises a middle plate substrate and a frame substrate, wherein the middle plate substrate comprises a first basic surface and a second basic surface arranged opposite to the first basic surface, wherein the frame substrate is convexly arranged at the edge of the first basic surface, wherein the frame substrate comprises a basic side frame, and wherein each of the basic side frames comprises an inner reference surface;

forming a protective layer on the surface of the shell substrate;

Using a laser engraving process to remove part of the protective layer on the shell substrate to expose the first basic surface and part of the inner reference surface;

Etching the shell substrate by an etching process to obtain a second shell substrate, the middle plate substrate forms a second middle plate substrate, the first basic surface forms a third basic surface, and the surface of the second middle plate substrate has a grain boundary;

Remove the protective layer.

This method uses etching to reduce the thickness of the shell. The etching process does not generate processing stress, which improves the strength of the shell and reduces the processing cost. The etching process is used to thin the thickness of the middle plate to achieve partial or complete thinning of the middle plate, which can provide more space for the battery and increase the battery capacity.

In one embodiment, the method further includes performing surface processing on the second substrate of the shell, so that the appearance of the shell is brighter, more delicate and smoother, and the corrosion resistance, hardness, wear resistance, insulation, heat resistance, etc. of the shell surface are greatly improved.

In one embodiment, the shell substrate is made of 6013 aluminum alloy or 7075 aluminum alloy. After etching the shell substrate, the thickness of the second middle plate substrate is 0.25 mm.

In one embodiment, the shell substrate is made of particle-reinforced aluminum-based composite material, and the thickness of the second middle plate substrate is 0.2 mm.

In one embodiment, the undercut portion is a convex structure or a concave structure. The concave structure is a groove structure, and the cross-section of the groove along the width direction of the middle plate can be rectangular, arc-shaped or trapezoidal; the convex structure is a protrusion, and the cross-section of the protrusion along the width direction of the middle plate can be rectangular and inverted trapezoidal, or include a plane facing away from the first surface and an arc-shaped surface connected to the first surface and concave toward the middle plate.

In one embodiment, in the step of etching the shell substrate by an etching process, an undercut portion is formed at the connection between the inner reference surface and the third basic surface, and the first surface and the surface of the undercut portion are crystal interfaces;

In one embodiment, the roughness of the first surface is greater than or equal to 0.5.

In a third aspect, the present application also provides an electronic device, which includes the above-mentioned shell and battery, the shell includes a battery compartment, the middle plate is the bottom wall of the battery compartment, and the battery is installed in the battery compartment.

The housing of the electronic device shown in the present application is an integrated structure, which can ensure the dimensional accuracy and structural rigidity of the housing, and can also ensure the flatness of the middle plate. It can avoid the unreliability of the assembly structure of the middle plate and the frame, and avoid affecting the waterproof performance and flatness of the entire housing due to the height difference between the split structures; it can also avoid the problem of screw assembly affecting the battery capacity during the assembly process of the housing.

What is important is that the middle plate of the shell is thinned by etching after CNC machining. No machining stress is generated during the etching process, and the thickness of the middle plate is thinned to 0.2mm or more and 0.25mm or less, so as to achieve the thinness of electronic equipment. Compared with reducing the thickness of the middle plate by CNC machining, the middle plate can only be kept at 0.3mm or more. If the thickness continues to decrease, it cannot be processed by CNC, or the stress of the middle plate will be greatly reduced, and even the middle plate will be broken and deformed.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solution of the present application, the drawings required for use in the implementation manner will be briefly introduced below. Obviously, the drawings described below are only some implementation manners of the present application. For ordinary technicians in this field, other drawings can be obtained like these drawings without paying any creative work.

FIG1 is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application;

FIG2 is a schematic structural diagram of a housing in the electronic device shown in FIG1 ;

FIG3a is a cross-sectional schematic diagram of the assembly of the housing and the battery shown in FIG1 ;

FIG3 b is a schematic cross-sectional view of an embodiment of a groove of a housing in the electronic device shown in FIG1 ;

FIG3c is a schematic cross-sectional view of another embodiment of a groove of a housing in the electronic device shown in FIG1 ;

FIG4a is a schematic cross-sectional view of an embodiment of a protrusion of a housing in the electronic device shown in FIG1 ;

FIG4b is a schematic diagram of the cross-sectional structure of a second embodiment of a housing protrusion in the electronic device shown in FIG1;

FIG4c is a schematic diagram of the cross-sectional structure of a third embodiment of a protruding portion of a housing in the electronic device shown in FIG1 ;

FIG5 is a schematic cross-sectional view of a fourth embodiment of the housing of the electronic device shown in FIG1 ;

FIG6 is an enlarged schematic diagram of the surface of the first surface of the middle plate and the undercut portion shown in FIG2 ;

FIG7 is a flow chart of a method for manufacturing the housing shown in FIG2 ;

FIG8 is a schematic diagram of the cross-sectional structure of the housing substrate after executing step S1 in FIG7;

FIG9 is a schematic diagram of the cross-sectional structure of the housing substrate after executing step S2 in FIG7 ;

FIG10 is a schematic diagram of the cross-sectional structure of the housing substrate after executing step S3 in FIG7 ;

FIG11 is a schematic diagram of the cross-sectional structure of the second base of the housing after executing step S4 in FIG7;

FIG. 12 is a surface microscopic morphology diagram of a middle plate in the prior art.

The names corresponding to the figure marks in the figure are: 1000 electronic device, 100 shell, 200 screen, 300 battery, 10 middle plate, 13 baffle, 20 frame, 21 metal parts, 22 plastic parts, 23 appearance surface, 24 first sub-frame, 25 second sub-frame, 26 inner side surface, 27 groove, 28 protrusion, 30 battery compartment, 40 protective layer, 101 first surface, 102 second surface, 10a middle plate substrate, 20a frame substrate, 20b second frame substrate, 10b second middle plate substrate, 101a first basic surface, 102a second basic surface, 101b third basic surface, 102b fourth basic surface, 201a first basic side frame, 202a second basic side frame, 203a inner reference surface, 203b second inner reference surface, D shell substrate, E shell second substrate.

DETAILED DESCRIPTION

The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

For ease of understanding, the terms involved in the embodiments of the present application are first explained.

Please refer to FIG1 , which is a schematic diagram of the structure of an electronic device 1000 provided in an embodiment of the present application. An embodiment of the present application provides an electronic device 1000, and the electronic device 1000 includes but is not limited to a cell phone, a notebook computer, a tablet personal computer, a laptop computer, a personal digital assistant, a television, a wearable device, or a mobile device, etc. In the embodiment of the present application, the electronic device 1000 is described by taking a mobile phone as an example. In the embodiment shown in FIG1 , the electronic device 1000 is in the shape of a rectangular flat plate. In some other embodiments, the shape of the electronic device 1000 may also be a square flat plate, a circular flat plate, an elliptical flat plate, etc.

For ease of description, in this application, the length direction of the electronic device 1000 is defined as the X-axis direction, the width direction of the electronic device 1000 is defined as the Y-axis direction, and the height direction of the electronic device 1000 is defined as the Z-axis direction. The X-axis, Y-axis and Z-axis directions are perpendicular to each other. It should be noted that the directional terms such as "upper" and "lower" involved in this application are described with reference to the orientation shown in Figure 1, with the positive direction of the Z-axis being "upper" and the negative direction of the Z-axis being "lower". It does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

The electronic device 1000 includes a housing 100, a screen 200 and a back cover (not shown). The screen 200 and the back cover are respectively mounted on opposite sides of the housing 100. The back cover is used to cover the battery of the electronic device 1000 and is also the back shell of the electronic device 1000. The back cover may include a plate body and a frame body connected to the edge of the plate body. The screen 200 is used to display the display screen and information of the electronic device 1000. The housing 100 is the supporting body of the electronic device 1000 and is used to carry the electronic devices inside the electronic device 1000 (not shown). The electronic devices inside the electronic device 1000 include circuit boards, processors, speaker modules, cameras, antennas, batteries, etc. and devices that realize various functions of the electronic device 1000.

The housing 100 may be a middle frame, or a middle frame and a back cover. The following text of this application mainly describes in detail the structure and manufacturing method of the housing 100 as a middle frame as an example.

Please refer to Figure 2 and Figure 3a, Figure 2 is a schematic diagram of the structure of the housing 100. Figure 3a is a schematic cross-sectional diagram of the housing and battery assembly shown in Figure 1.

The housing 100 includes a middle plate 10 and a frame 20, and the frame 20 and the middle plate 10 are integrally formed. The frame 20 is arranged around the periphery of the middle plate 10. In the present embodiment, the middle plate 10 is a rectangular thin plate, which includes a first surface 101 and a second surface 102. The first surface 101 and the second surface 102 are arranged in back-to-back relationship along the thickness direction of the middle plate 10 (Z-axis direction in the figure). The second surface 102 carries the screen 200, and the frame 20 is connected to the edge of the first surface 101. The back cover covers one side of the first surface 101 and is connected to the frame 20.

The middle plate 10 of this embodiment is made of aluminum alloy material. The thickness t of the middle plate 10 is less than 0.3 mm. For example, the thickness t of the middle plate 10 can be greater than or equal to 0.2 mm and less than or equal to 0.25 mm.

In this embodiment, the frame 20 includes a metal part 21 and a plastic part 22. The metal part 21 is integrally formed with the middle plate 10. The metal part 21 and the plastic part 22 are formed by a nano injection molding process, and the plastic part 22 is embedded in part of the metal part 21. Embedding means that the plastic part 22 is partially coated on the metal part 21. Among them, the setting of the plastic part 22 facilitates the setting of the antenna on the metal part 21 and the middle plate 10, and facilitates the setting of the grounding of the frame 20 and the middle plate 10. Exemplarily, along the length direction of the frame 20 (the direction of the X axis in the figure), part of the frame 20 only includes the metal part 21, and the metal part 21 not coated with the plastic part 22 can be used as the antenna of the electronic device 1000; part of the frame 20 includes the metal part 21 and the plastic part 22, and the plastic part 22 is embedded in the metal part 21. The plastic part 22 can separate the antenna from other metal parts 21. Among them, the connection position and form of the plastic part 22 and the metal part 21 are not limited. The outer surface of the metal member 21 of the present embodiment serves as the appearance surface 23 of the frame 20 , that is, the surface of the metal member 21 serves as the appearance surface 23 , thereby improving the aesthetic appearance.

The housing 100 also includes a battery compartment 30 for accommodating batteries (not shown). Specifically, two baffles 13 are convexly provided on the first surface 101 of the middle plate 10. The baffles 13 extend along the width direction of the middle plate 10 (the direction of the Y axis shown in the figure), and the two opposite ends of each baffle 13 are connected to the frame 20. The two baffles 13 are arranged at intervals along the length direction of the middle plate 10 (the direction of the X axis shown in the figure). The two baffles 13, part of the middle plate 10 and part of the frame 20 form the battery compartment 30, and part of the first surface 101 is the bottom surface of the battery compartment 30. The size of the battery compartment 30 is compatible with the shape and size of the battery. The back cover is covered on the housing 100 and covers the battery compartment 30. The space formed between the back cover and the first surface 101 is used to accommodate electronic devices such as circuit boards and batteries of the electronic device 1000 (not shown). In other embodiments, the thickness of the part of the middle plate 10 that encloses the battery compartment 30 can be less than the thickness of other parts of the middle plate 10.

The battery 300 is accommodated in the battery compartment 30, and the surface of the battery 300 away from the rear cover of the electronic device 1000 is in contact with the first surface 101 of the middle plate 10, and the rear cover and the battery compartment 30 limit the battery 300. The battery 300 is electrically connected to the circuit board of the electronic device 1000, thereby providing power to the electronic device 1000.

In this embodiment, the frame 20 includes a first sub-frame 24 and a second sub-frame 25, and the first sub-frame 24 and the second sub-frame 25 are arranged relatively along the width direction of the shell 100 (the direction of the Y axis in the figure). The frame 20 is also provided with an inner side surface 26, and the inner side surface 26 and the appearance surface 23 are arranged back to back along the thickness direction of the frame 20 (the direction of the Y axis in the figure). The inner side surface 26 is connected to the first surface 101. A side erosion portion is provided at the connection between the frame 20 and the middle plate 10, specifically, a side erosion portion is provided at the connection between the inner side surface 26 and the first surface 101. In other embodiments, the frame 20 is arranged around the periphery of the middle plate 10, and a side erosion portion is provided at the connection between the inner side surface 26 of the entire frame 20 and the first surface 101 of the middle plate 10. This embodiment is described by taking the frame including two sub-frames as an example.

In this embodiment, the inner side surface 26 of the frame 20 is provided with a groove 27, and the groove 27 is formed by the inner side surface 26 being recessed into the inner part of the frame 20. The groove 27 is located at the connection between the inner side surface 26 of the frame 20 and the first surface 101 of the middle plate 10, and the first surface 101 is a part of the groove side wall of the groove 27. It can also be understood that the connection between the first surface 101 and the inner side surface 26 forms the groove 27. The groove 27 is provided on the part of the frame 20 that surrounds the battery compartment 30, that is, on the inner side surface 26 of the first sub-frame 24 and the second sub-frame 25, and the groove 27 on the first sub-frame 24 and the groove 27 on the second sub-frame 25 are arranged oppositely. The length direction of the groove 27 extends along the length direction of the frame 20 (the direction of the X axis in the figure). The length of the groove 27 in this embodiment is the same as the length of the battery compartment 30. Please refer to Figures 3b and 3c, Figure 3b is a schematic cross-sectional diagram of an embodiment of the groove of the housing of the electronic device shown in Figure 1, and Figure 3c is a schematic cross-sectional diagram of another embodiment of the groove of the housing of the electronic device shown in Figure 1. Along the width direction of the middle plate 10 , the cross-section of the groove 27 may be rectangular, arc-shaped or trapezoidal, as shown in FIG. 3 b and FIG. 3 c .

In other embodiments, the frame 20 is disposed around the periphery of the middle plate 10 , and the connection between the inner side 26 of the entire frame 20 and the first surface 101 of the middle plate 10 is provided with a groove 27 . That is, the groove 27 can be disposed around the periphery of the middle plate 10 .

As shown in Fig. 4a, Fig. 4b and Fig. 4c, Fig. 4a is a schematic cross-sectional diagram of an embodiment of a protrusion of the shell in the electronic device shown in Fig. 1, Fig. 4b is a schematic cross-sectional diagram of a second embodiment of the protrusion of the shell in the electronic device shown in Fig. 1, and Fig. 4c is a schematic cross-sectional diagram of a third embodiment of the protrusion of the shell in the electronic device shown in Fig. 1. In the second embodiment, a protrusion 28 is provided at the connection between the inner side surface 26 of the frame 20 and the first surface 101 of the middle plate 10, and the protrusion 28 protrudes from the first surface 101 and is connected to the inner side surface 26 of the frame 20. In this embodiment, the protrusion 28 is located in the battery compartment 30, and specifically, two protrusions 28 are provided at the connection between the first sub-frame 24 and the second sub-frame 25 and the first surface 101 of the middle plate 10. As shown in Fig. 4a and Fig. 4c, along the width direction of the middle plate 10, the cross-sectional shape of the protrusion 28 can be a rectangle and an inverted trapezoid. As shown in FIG. 4 b , the protruding portion 28 further includes a plane facing away from the first surface 101 and an arc-shaped surface connected to the first surface 101 and concavely disposed toward the middle plate 10 .

Please refer to Figure 5, which is a cross-sectional schematic diagram of the fourth embodiment of the shell in the electronic device shown in Figure 1. In the fourth embodiment, the shell 100 includes a groove 27 and a protrusion 28. Specifically, the groove 27 is located at the connection between the inner side surface 26 of the first sub-frame 24 and the first surface 101 of the middle plate 10, and the protrusion 28 protrudes from the first surface 101 and is connected to the inner side surface 26 of the first sub-frame 24. It can be understood that the groove 27 and the protrusion 28 are relatively arranged along the width direction of the shell 100 (the direction of the Y axis in the figure). Among them, the shape of the cross section of the groove 27 is an arc shape, and the shape of the cross section of the protrusion 28 is a rectangle.

It should be noted that the side erosion portion of any of the above embodiments is presented in the form of a groove 27 or a protrusion 28, and the side erosion portion is formed during the etching process of the middle plate 10. The etching of the middle plate 10 is to reduce the thickness of the middle plate 10, that is, the dimension between the first surface 101 and the second surface 102, so as to achieve the purpose of making the housing 100 thin and light.

In the embodiment of the present application, the middle plate 10 and the frame 20 are made by an integrated molding method combined with an etching process, wherein the thickness t of the middle plate 10 is less than 0.3 mm. For example, the thickness t of the middle plate 10 can be greater than or equal to 0.2 mm and less than or equal to 0.25 mm. The entire middle plate 10 is relatively thin, and the thickness of the middle plate 10 of the battery compartment 30 is reduced compared to the thickness of the prior art, which can achieve the thinness and lightness of the shell 100, and then achieve the thinness and lightness of the electronic device 1000. At the same time, the shell 100 is an integrated molding structure, which can ensure the dimensional accuracy and structural rigidity of the shell 100, and can also ensure the flatness of the middle plate 10. That is, it can avoid the unreliability of the assembly structure of the middle plate 10 and the frame 20, and avoid affecting the waterproof performance and flatness of the entire shell 100 due to the height difference between the split structures; it can also avoid the problem of the screw assembly of the shell 100 affecting the capacity of the battery 300 during the assembly process.

Please refer to FIG. 6, which is an enlarged schematic diagram of the surface of the first surface 101 and the side etching portion of the middle plate 10 shown in FIG. 2. The first surface 101 and the side etching portion of the middle plate 10 are formed by etching. The middle plate 10 is an aluminum alloy material. Through a microscope lens, it can be observed that the surface of the first surface 101 and the side etching portion of the middle plate 10 is corroded by the chemical etching solution to form a grain boundary, that is, the surface of the first surface 101 and the side etching portion has a grain boundary feature and presents a typical grain feature, which can be understood as inorganic processing. The roughness of the first surface 101 of the grain boundary in this embodiment is greater than or equal to 0.5. Optionally, the surface roughness Ra of the first surface 101 and the side etching portion formed by etching is 3.41. Among them, a crystal with completely consistent lattice orientation (i.e., atomic arrangement direction) inside the crystal is called a single crystal; the metal material actually used, even if the volume is very small, still contains many small crystals inside, because these small crystals with basically the same lattice phase are irregular in shape and granular, so they are called "grains". In polycrystalline materials, due to the different orientations of the grains, there is an interface between the grains, which is called a grain boundary. Since the particle arrangement orientations of the two grains on the grain boundary are somewhat different, both try to make the particle arrangement on the grain boundary conform to their own orientation. When equilibrium is reached, the atoms on the grain boundary form a certain transitional arrangement. The irregular arrangement of atoms on the grain boundary causes a loose structure, which also makes the grain boundary have some characteristics different from the grains. The atomic arrangement on the grain boundary is looser than that inside the grain, so the grain boundary is easily exposed after being corroded (thermal erosion, chemical corrosion).

Please refer to FIG. 7 , which is a flow chart of a method for manufacturing the housing 100 shown in FIG. 2 . The method for manufacturing the housing 100 includes the following steps:

Please refer to FIG8 , which is a schematic diagram of the cross-sectional structure of the shell substrate D after executing step S1 in FIG7 . Step S1, providing a shell substrate D. The shell substrate D includes a middle plate substrate 10a and a frame substrate 20a, the middle plate substrate 10a includes a first basic surface 101a facing the positive direction of the Z axis and a second basic surface 102a arranged opposite to the first basic surface 101a, and the frame substrate 20a is convexly arranged at the edge of the first basic surface 101a. Among them, the frame substrate 20a includes a first basic side frame 201a and a second basic side frame 202a, the first basic side frame 201a and the second basic side frame 202a both include an inner reference surface 203a, and the inner reference surface 203a is connected to the first basic surface 101a. The first basic side frame 201a and the second basic side frame 202a form a accommodating area with the middle plate substrate 10a.

Specifically, step S1 also includes:

A metal substrate is provided, and a reference surface of the metal substrate is processed by a CNC (Computer numerical control machine tools) machining method to obtain a metal workpiece. The metal workpiece includes a first part and a second part. The first part is a plate-like structure, and the second part is arranged around the periphery of the first part.

The second part is provided with a plurality of embedding holes, which play a positioning role in the nano injection molding process. The material of the metal substrate can be a blank formed by extrusion molding and solid solution aging heat treatment of 6013 aluminum alloy and 7075 aluminum alloy.

The metal workpiece (not shown) is injection molded by using nano injection molding technology to form a basic plastic part in the embedding hole of the second part of the metal workpiece to obtain an injection molded part.

The injection molded part is surface processed by CNC machining to obtain a shell substrate D. The shell substrate D includes a middle plate substrate 10a and a frame substrate 20a. The middle plate substrate 10a includes a first basic surface 101a and a second basic surface 102a that are arranged opposite to each other, and the first basic surface 101a is arranged in the positive direction of the Z axis. The frame substrate 20a includes a basic side frame. The basic side frame can surround the periphery of the first basic surface 101a, or it can be two basic side frames. In this embodiment, two basic side frames are described as an example, and the two basic side frames are respectively arranged on opposite sides of the width direction of the first basic surface 101a, and the two basic side frames can be named as the first basic side frame 201a and the second basic side frame 202a.

Specifically, in this step, when the material of the metal substrate is 6013 aluminum alloy or 7075 aluminum alloy, the thickness of the middle plate substrate 10a along the Z-axis direction is processed to 0.5 mm.

In other embodiments, the material of the metal substrate may be a particle-reinforced aluminum-based composite material. When the material of the metal substrate is a particle-reinforced aluminum-based composite material, the thickness of the middle plate substrate 10a along the Z-axis direction is processed to 0.4 mm.

Please refer to FIG. 9 , which is a schematic diagram of the cross-sectional structure of the housing substrate D after executing step S2 in FIG. 7 . Step S2, forming a protective layer 40 on the surface of the housing substrate D. In this step, the protective layer 40 covers the first basic surface 101a, the second basic surface 102a, the first basic side frame 201a and the second basic side frame 202a and the inner reference surface 203a. The protective layer 40 is an ink layer, and the protective layer 40 in this embodiment is formed by coating. In other embodiments, the protective layer 40 can also be formed by other materials and other methods.

Step S3, using a laser engraving process to remove part of the protective layer on the shell substrate D, exposing the first basic surface 101a and part of the two inner reference surfaces 203a. Please refer to Figure 10, which is a schematic diagram of the cross-sectional structure of the shell substrate D after performing step S3 in Figure 7. In this step, the protective layer 40 of the first basic surface 101a and the protective layer 40 at the connection between the first basic surface 101a and the two inner reference surfaces 203a are removed.

Step S4, etching the shell substrate D through an etching process to obtain a second shell substrate E; wherein the middle plate substrate 10a forms a second middle plate substrate 10b, and a side etching portion is formed on part of the two inner reference surfaces 203a. As shown in FIG. 11, FIG. 11 is a schematic diagram of the cross-sectional structure of the second shell substrate E after executing step S4 in FIG. 7. The first basic surface 101a is etched along the thickness direction of the middle plate substrate 10a (the direction of the Z axis in the figure) to remove a portion of the material in the thickness direction of the middle plate substrate 10a (the direction of the Z axis in the figure) to form a second middle plate substrate 10b. The first basic surface 101a is etched to form a third basic surface 101b. The thickness t of the second middle plate substrate 10b along the Z axis is 0.2 mm-0.25 mm.

In this step, a chemical etchant is used for etching. When the material of the metal substrate is 6013 aluminum alloy or 7075 aluminum alloy, the thickness t of the middle plate substrate 10a along the Z-axis direction is etched to 0.25 mm.

In other embodiments, the material of the metal substrate may be a particle-reinforced aluminum-based composite material. In this step, when the material of the metal substrate is a particle-reinforced aluminum-based composite material, the thickness t of the middle plate substrate 10a along the Z-axis direction may be etched to 0.2 mm due to the higher elastic modulus and better strength of the particle-reinforced aluminum-based composite material.

In this step, while the chemical etching solution etches the first basic surface 101a, a side etching portion is formed at the connection between the first basic surface 101a and the two inner reference surfaces 203a. It can be understood that the inner reference surface 203a forms a second inner reference surface 203b after etching, and the side etching portion is located at the connection between the second inner reference surface 203b and the third basic surface 101b, and the frame substrate 20a forms a frame second frame substrate 20b after etching. The material surface of the first surface 101 and the side etching portion formed by etching in the embodiment of the method presents typical equiaxed crystal characteristics, and the surface roughness Ra is 3.41.

The undercut portion is a groove 27, a protrusion 28 or a combination of a groove 27 and a protrusion 28 in Fig. 3a, Fig. 3b, Fig. 3c and Fig. 4a, Fig. 4b, Fig. 4c. Wherein, the cross-sectional shape of the groove 27 can be a rectangle, an arc or a trapezoid. The cross-sectional shape of the protrusion 28 can be a rectangle and an inverted trapezoid. As shown in Fig. 4b, the cross-sectional shape of the protrusion 28 is a plane facing away from the first surface 101 and an arcuate surface connected to the first surface.

Step S5, removing the protective layer on the second substrate E of the housing. Specifically, a chemical detergent is used to clean the protective layer 40 shielded on the surface of the second substrate E of the housing.

Step S6, performing exterior surface processing on the second base E of the housing to form the housing 100. It should be noted that this method is described by taking the frames 20 on both sides of the middle plate 10 as an example, and the frames 20 at both ends of the middle plate are actually also processed to form the side erosion parts.

Please refer to Figure 3a, Figure 3b and Figure 3c again. The second middle plate substrate 10b forms the middle plate 10, the third basic surface 101b forms the first surface 101, the second basic surface 102a forms the second surface 102, and the second frame substrate 20b forms the frame 20. The thickness t of the middle plate 10 along the Z-axis direction is 0.2mm-0.25mm.

Specifically, a CNC processing method is used to process the appearance of the second substrate E of the shell, and the appearance surface of the second substrate E of the shell is polished with medium precision to make the appearance of the second substrate E of the shell brighter, more delicate and smoother; then, an anodizing method is used to process the surface of the second substrate E of the shell, so that a layer of oxide film is formed on the surface of the second substrate E of the shell, thereby greatly improving the corrosion resistance, hardness, wear resistance, insulation, heat resistance, etc. of the surface of the second substrate E of the shell; finally, blanking and laser engraving processes are performed to remove the waste on the surface of the second substrate E of the shell, ensuring that the surface of the second substrate E of the shell has a certain degree of cleanliness, so as to form the shell 100. It should be noted that after the polishing anodizing method and other processing processes, the increase or decrease in the thickness of the middle plate 10 can be ignored, and it can also be understood that it is within the tolerance range of the thickness of the middle plate 10, that is, the thickness of the middle plate 10 is 0.2mm-0.25mm.

In the embodiment of the present application, the frame 20 and the middle plate 10 of the shell 100 are integrally formed of aluminum alloy, which solves the technical problems of flatness, waterproofness and assembly accuracy stability existing in the split shell of the prior art (part of the middle plate is split from the middle plate at the corresponding battery compartment position, or the middle plate is split from the frame), and no processing stress is generated during the etching process, which improves the strength of the shell. In addition, the processing cost of the shell 100 is reduced; compared with the process limitations of CNC processing to form the middle plate, this embodiment uses etching to process the middle plate 10, which can improve the processing accuracy, further reduce the thickness of the middle plate 10, and achieve partial or complete thinning of the middle plate 10.

Please refer to Figure 12, which is a microscopic morphology of the surface of the middle plate in the prior art. Through the test lens, it can be observed that the surface formed by machining has obvious knife marks, and the surface roughness Ra is 0.36. By CNC machining the middle plate to reduce the thickness of the middle plate, it can actually only keep the middle plate at or above 0.3mm. If the thickness continues to decrease, it cannot be processed by CNC, or the stress of the middle plate is greatly reduced, and even the middle plate is broken and deformed.

The embodiments of the present application are introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of the present application. At the same time, for general technical personnel in this field, according to the idea of the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims (17)

1. A housing, characterized in that the housing comprises a middle plate and a frame, the middle plate comprises a first surface and a second surface disposed opposite to the first surface, The middle plate and the frame are integrally formed, and the frame is arranged at the edge of the first surface. The first surface has grain boundaries. 2 . The housing according to claim 1 , wherein the roughness of the first surface is greater than or equal to 0.5. 3 . The housing according to claim 1 , wherein the frame comprises an inner side surface, and an undercut portion is formed at a connection between the inner side surface and the first surface. 4 . The shell according to claim 1 , wherein the thickness of the middle plate is greater than or equal to 0.2 mm and less than or equal to 0.3 mm. 5 . The shell according to claim 1 , wherein the shell is made of 6013 aluminum alloy or 7075 aluminum alloy, and the thickness of the middle plate is 0.25 mm. 6. The shell according to claim 1 is characterized in that the material of the shell is a particle-reinforced aluminum-based composite material, and the thickness of the middle plate is 0.2 mm. 7 . The housing according to claim 3 , wherein a surface of the undercut portion has a grain boundary. 8. The shell according to claim 3 is characterized in that the side erosion portion is a groove recessed on the inner side surface and the first surface, and along the width direction of the middle plate, the cross-section of the groove is rectangular, arc-shaped or trapezoidal. 9. The shell according to claim 3 is characterized in that the side erosion portion is a protrusion protruding from the first surface and connected to the inner side surface, and along the width direction of the middle plate, the cross-section of the protrusion is rectangular or an inverted trapezoid; or, the protrusion includes a plane facing away from the first surface and an arc-shaped surface connected to the first surface and concave toward the middle plate. 10. A method for manufacturing a shell, characterized in that the method comprises: A shell substrate is provided, wherein the shell substrate comprises a middle plate substrate and a frame substrate, wherein the middle plate substrate comprises a first basic surface and a second basic surface arranged opposite to the first basic surface, wherein the frame substrate is convexly arranged at an edge of the first basic surface, wherein the frame substrate comprises a basic side frame, and wherein each of the basic side frames comprises an inner reference surface; forming a protective layer on the surface of the shell substrate; Using a laser engraving process to remove part of the protective layer on the shell substrate to expose the first basic surface and part of the inner reference surface; Etching the shell substrate by an etching process to obtain a second shell substrate, the middle plate substrate forms a second middle plate substrate, the first basic surface forms a third basic surface, and the surface of the second middle plate substrate has a grain boundary; Remove the protective layer. 11 . The shell manufacturing method according to claim 10 , characterized in that the method further comprises performing appearance surface processing on the second substrate of the shell. 12 . The shell manufacturing method according to claim 10 , wherein the shell substrate is made of 6013 aluminum alloy or 7075 aluminum alloy, and after etching the shell substrate, the thickness of the second middle plate substrate is 0.25 mm. 13 . The shell manufacturing method according to claim 10 , characterized in that the shell substrate is made of particle-reinforced aluminum-based composite material, and the thickness of the second middle plate substrate is 0.2 mm. 14 . The shell manufacturing method according to claim 10 , wherein the undercut portion is a convex structure or a concave structure. 15. The shell manufacturing method according to claim 10 is characterized in that in the step of etching the shell substrate through an etching process, an undercut portion is formed at the connection between the inner reference surface and the third basic surface after etching; and the surface of the undercut portion has a grain boundary. 16 . The housing according to claim 10 , wherein the roughness of the first surface is greater than or equal to 0.5. 17. An electronic device, characterized in that the electronic device comprises a housing and a battery as described in any one of claims 1 to 9, the housing comprises a battery compartment, the middle plate is a bottom wall of the battery compartment, and the battery is installed in the battery compartment.