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

Abstract

The application provides a shell, a shell manufacturing method and electronic equipment. The shell comprises a middle plate and a frame, wherein the middle plate comprises a first surface and a second surface which is arranged back 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 comprises an inner side surface, and a side etching part is formed at the joint of the inner side surface and the first surface. According to the application, the middle plate is processed by the etching method, so that the partial or total thinning of the middle plate is realized, and the thinning of the electronic equipment is further realized.

Description

Shell, shell manufacturing method and electronic equipment

Technical Field

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

Background

People continuously increase the demands for portability and reliability of electronic devices such as mobile phones and tablet personal computers, and push the electronic devices to gradually develop to be light and thin and light, so that the shells, such as rear covers and shells, of the electronic devices such as the mobile phones are used as bearing and protecting main components, not only have enough structural strength, but also have the thickness dimension and weight of the electronic devices such as the mobile phones, so that the thickness and weight of the electronic devices are reduced. Particularly, the reduction of the thickness of the shell can save the internal space of the electronic equipment, and how to reduce the thickness dimension of the shell under the condition of meeting the structural strength requirement of the shell is a technical problem solved in the technical field of manufacturing of the electronic equipment.

Disclosure of Invention

The application provides a shell, a shell manufacturing method and electronic equipment, which are used for reducing the thickness of the whole electronic equipment and ensuring that the shell has enough rigidity performance.

In a first aspect, the present application provides a housing, where the housing includes a middle plate and a frame, the middle plate includes a first surface and a second surface opposite to the first surface, the middle plate and the frame are integrally formed, and the frame is disposed at an edge of the first surface. The first surface has grain boundaries.

The integrated structure of the shell solves the technical problems of flatness, waterproofness and stability of assembly precision existing in split type shells (the split type shells of part of the middle plates and the middle plates corresponding to the positions of the battery bins or the split type shells of the middle plates and the frames) in the prior art; moreover, the method is also applicable to the field of the present invention. The first surface is provided with a grain boundary, the surface is formed by etching the aluminum alloy material, the etching process reduces the thickness of the middle plate, stress cannot be generated on the middle plate, and compared with CNC processing, the middle plate which is thinner can be processed, and then the inner space of the shell can be lifted, or the thickness of the shell is reduced.

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 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 0.2mm and less than or equal to 0.3mm. The thickness of the middle plate is processed through an etching process, so that compared with CNC processing, the stress of the middle plate is prevented from being generated to influence the strength of the middle plate and prevent the middle plate from deforming; and etching may achieve a thinner dimension of the midplane than CNC machining.

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

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

In one embodiment, the undercut surface has grain boundaries.

In one embodiment, the undercut is a groove concavely formed in the inner side surface and the first surface, and a cross section of the groove is rectangular, arc-shaped or trapezoid along a width direction of the middle plate.

In one embodiment, the undercut is a protruding portion protruding from the first surface and connected to the inner side surface, and a cross section of the protruding portion is rectangular and inverted trapezoid along a width direction of the middle plate; or the convex part comprises a plane facing away from the first surface and an arc-shaped surface which is connected with the first surface and concavely arranged towards the middle plate.

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

Providing a shell substrate, wherein the shell substrate comprises a middle plate substrate and a frame substrate, the middle plate substrate comprises a first basic surface and a second basic surface which is opposite to the first basic surface, the frame substrate is convexly arranged at the edge of the first basic surface, the frame substrate comprises basic side frames, and the basic side frames comprise inner side reference surfaces;

Forming a protective layer on the surface of the shell base material;

Removing part of the protective layer on the shell substrate by adopting a laser etching process, and exposing the first basic surface and part of the inner side reference surface;

Etching the shell substrate through an etching process to obtain a shell second substrate, wherein 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 is provided with a grain boundary;

And removing the protective layer.

The thickness of the shell is thinned in an etching mode, processing stress is not generated in the etching processing process, the strength of the shell is improved, the processing cost is reduced, the thickness of the middle plate is thinned in an etching processing mode, partial or whole thinning of the middle plate is realized, more space can be provided for a battery, and the battery capacity is improved.

In one embodiment, the method further comprises performing surface appearance process treatment on the second substrate of the shell, wherein the surface appearance of the shell is brighter, finer and smoother, and the corrosion resistance, hardness, wear resistance, insulation, heat resistance and the like of the surface of the shell are greatly improved.

In one embodiment, the housing substrate is made of 6013 aluminum alloy or 7075 aluminum alloy, and the thickness of the second middle plate substrate is 0.25mm after the housing substrate is etched.

In one embodiment, the shell substrate is a particle reinforced aluminum matrix composite, and the thickness of the second middle plate substrate is 0.2mm.

In one embodiment, the undercut is a convex or concave configuration. The concave structure is a groove structure, and the cross section of the groove can be rectangular, arc-shaped or trapezoid along the width direction of the middle plate; the protruding structure is a protruding portion, and along the width direction of the middle plate, the shape of the cross section of the protruding portion can be rectangular or inverted trapezoid, or the protruding structure comprises a plane opposite to the first surface and an arc-shaped surface which is connected with the first surface and concavely arranged towards the middle plate.

In one embodiment, in the step of etching the shell substrate through the etching process, a side etching part is formed at the connection part of the inner side reference surface and the third basic surface, and the surfaces of the first surface and the side etching part are in a crystal interface;

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

In a third aspect, the present application further provides an electronic device, where the electronic device includes the housing and a battery, the housing includes a battery compartment, the middle plate is a bottom wall of the battery compartment, and the battery is mounted in the battery compartment.

The shell in the electronic equipment disclosed by the application is of an integrated structure, so that the dimensional accuracy and structural rigidity of the shell can be ensured, and the planeness of the middle plate can also be ensured. The unreliability of the assembly structure of the middle plate and the frame can be avoided, and the influence on the waterproof performance and the flatness of the whole shell due to the difference of the height between the split structures is avoided; the problem that the screw assembly of the shell affects the battery capacity in the assembly process can also be avoided.

Importantly, the middle plate of the shell is thinned through etching after CNC processing, processing stress is not generated in the etching process, and the thickness of the middle plate is thinned to be more than or equal to 0.2mm and less than or equal to 0.25mm, so that the thinning of the electronic equipment is realized. Compared with the method for reducing the thickness of the middle plate by CNC machining the middle plate, the thickness of the middle plate can only be maintained to be more than or equal to 0.3mm in practice, if the thickness is reduced continuously, the stress of the middle plate can be reduced greatly, and even the middle plate is broken and deformed.

Drawings

In order to more clearly illustrate the technical solutions of the present application, the drawings that are needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and other drawings may be obtained by those skilled in the art without the inventive effort.

Fig. 1 is a schematic structural diagram of an electronic device according to an embodiment of the present application;

FIG. 2 is a schematic view of the housing of the electronic device of FIG. 1;

FIG. 3a is a schematic cross-sectional view of the housing and battery assembly shown in FIG. 1;

FIG. 3b is a schematic cross-sectional view of one embodiment of a recess of a housing in the electronic device of FIG. 1;

FIG. 3c is a schematic cross-sectional view of another embodiment of a recess of a housing in the electronic device of FIG. 1;

FIG. 4a is a schematic cross-sectional view of one embodiment of a protrusion of a housing in the electronic device shown in FIG. 1;

FIG. 4b is a schematic cross-sectional view of a second embodiment of a housing protrusion in the electronic device of FIG. 1;

FIG. 4c is a schematic cross-sectional view of a third embodiment of a housing protrusion in the electronic device of FIG. 1;

FIG. 5 is a schematic cross-sectional diagram of a fourth embodiment of a housing in the electronic device of FIG. 1;

FIG. 6 is an enlarged schematic view of the first surface of the midplane and the surface of the undercut shown in FIG. 2;

FIG. 7 is a flow chart of a method of making the housing shown in FIG. 2;

FIG. 8 is a schematic cross-sectional view of the housing base material of FIG. 7 after step S1 is performed;

FIG. 9 is a schematic cross-sectional view of the housing base material after step S2 is performed in FIG. 7;

FIG. 10 is a schematic cross-sectional view of the housing base material after step S3 is performed in FIG. 7;

FIG. 11 is a schematic cross-sectional view of the second substrate of the housing of FIG. 7 after step S4;

Fig. 12 is a surface microtopography of a prior art midplane.

The corresponding names of the reference numerals in the drawings are: the electronic device comprises a 1000 electronic device, a 100 shell, a 200 screen, 300 batteries, 10 middle plates, 13 baffles, 20 frames, 21 metal pieces, 22 plastic pieces, 23 appearance surfaces, 24 first sub frames, 25 second sub frames, 26 inner side surfaces, 27 grooves, 28 convex parts, 30 battery bins, 40 protective layers, 101 first surfaces, 102 second surfaces, 10a middle plate substrates, 20a frame substrates, 20b second frame substrates, 10b second middle plate substrates, 101a first basic surfaces, 102a second basic surfaces, 101b third basic surfaces, 102b fourth basic surfaces, 201a first basic side frames, 202a second basic side frames, 203a inner side reference surfaces, 203b second inner side reference surfaces, D shell substrates and E shell second substrates.

Detailed Description

The following description of the embodiments of the present application will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

For convenience of understanding, terms involved in the embodiments of the present application will be explained first.

Referring to fig. 1, fig. 1 is a schematic structural diagram of an electronic device 1000 according to an embodiment of the application. The embodiment of the application provides an electronic device 1000, where the electronic device 1000 includes, but is not limited to, a mobile phone (cellphone), a notebook computer (notebook computer), a tablet computer (tablet personal computer), a laptop computer (laptop computer), a personal digital assistant (personal DIGITAL ASSISTANT), a television (television), a wearable device (wearabledevice), or a vehicle-mounted device (mobiledevice), etc. In the embodiment of the present application, the electronic device 1000 is illustrated by taking a mobile phone as an example. In the embodiment shown in fig. 1, the electronic device 1000 has a rectangular flat plate shape, and in other embodiments, the electronic device 1000 may have a square flat plate shape, a circular flat plate shape, an oval flat plate shape, or the like.

For convenience of description, in the present application, a length direction of the electronic apparatus 1000 is defined as an X-axis direction, a width direction of the electronic apparatus 1000 is defined as a Y-axis direction, and a height direction of the electronic apparatus 1000 is defined as a Z-axis direction. The X-axis, Y-axis and Z-axis directions are perpendicular to each other. The terms "upper" and "lower" and the like in the present application are used in the description of the orientation shown in fig. 1, and are not intended to indicate or imply that the apparatus or element to be referred to must have a specific orientation, be constructed and operated in a specific orientation, and should not be construed as limiting the application.

The electronic device 1000 includes a housing 100, a screen 200, and a rear cover (not labeled). The screen 200 and the rear cover are respectively mounted on opposite sides of the case 100, and the rear cover is used for covering the battery of the electronic device 1000, and is also a back case of the electronic device 1000. The back cover may include a plate body and a frame body coupled to an edge of the plate body. The screen 200 is used to display a display screen and information of the electronic device 1000. The housing 100 is a supporting body of the electronic apparatus 1000 for carrying electronic components (not shown) inside the electronic apparatus 1000. The electronic devices inside the electronic apparatus 1000 include a circuit board, a processor, a speaker module, a camera, an antenna, a battery, and the like, and devices that realize various functions of the electronic apparatus 1000.

The housing 100 may be a middle frame, or may be a middle frame and a rear cover. The structure and manufacturing method of the present application will be described in detail below mainly taking the housing 100 as a middle frame.

Referring to fig. 2 and 3a, fig. 2 is a schematic structural diagram of the housing 100. Fig. 3a is a schematic cross-sectional view of the housing and battery assembly shown in fig. 1.

The housing 100 includes a middle plate 10 and a rim 20, and the rim 20 and the middle plate 10 are integrally formed. A rim 20 is provided around the periphery of the midplane 10. In this 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 disposed opposite to each other along the thickness direction (Z-axis direction in the drawing) of the middle plate 10. The second surface 102 carries the screen 200, and the frame 20 is connected to the edge of the first surface 101. The rear 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 an aluminum alloy material. The thickness t of the middle plate 10 is less than 0.3mm. For example, the thickness t of the middle plate 10 may be 0.2mm or more and 0.25mm or less.

In this embodiment, the frame 20 includes a metal member 21 and a plastic member 22. Wherein the metal piece 21 is integrally formed with the middle plate 10. The metal piece 21 and the plastic piece 22 are formed through a nano injection molding process, and part of the metal piece 21 is embedded with the plastic piece 22. Embedding means that the plastic part 22 is partially coated on the metal part 21. The plastic member 22 is convenient for arranging the antenna on the metal member 21 and the middle plate 10, and is convenient for arranging the frame 20 and the middle plate 10 to be grounded. Illustratively, along the length direction (the direction of the X-axis in the drawing) of the frame 20, a part of the frame 20 only includes the metal piece 21, and the metal piece 21 without the plastic piece 22 is used as an antenna of the electronic device 1000; the partial frame 20 comprises a metal piece 21 and a plastic piece 22, and the plastic piece 22 is embedded in the metal piece 21. The plastic piece 22 may separate the antenna from the other metal pieces 21. The connection position and shape of the plastic member 22 and the metal member 21 are not limited. The outer surface of the metal piece 21 in this embodiment is used as the appearance surface 23 of the frame 20, that is, the surface of the metal piece 21 is used as the appearance surface 23, so as to improve the aesthetic feeling of appearance.

The housing 100 further includes a battery compartment 30 for receiving a battery (not shown). Specifically, the first surface 101 of the middle plate 10 is convexly provided with two baffles 13, the baffles 13 extend along the width direction (the direction of the Y axis in the drawing) of the middle plate 10, opposite ends of each baffle 13 are connected with the frame 20, the two baffles 13 are arranged at intervals along the length direction (the direction of the X axis in the drawing) of the middle plate 10, the two baffles 13, part of the middle plate 10 and part of the frame 20 enclose a battery compartment 30, and part of the first surface 101 is the bottom surface of the battery compartment 30. The battery compartment 30 is sized to accommodate the shape and size of the battery. The rear cover covers the case 100 and covers the battery compartment 30, and a space formed between the rear cover and the first surface 101 is used to accommodate electronic components (not shown) such as a circuit board, a battery, and the like of the electronic apparatus 1000. In other embodiments, the thickness of the portion of the midplane 10 surrounding the battery compartment 30 may be less than the thickness of other portions of the midplane 10.

The battery 300 is accommodated in the battery compartment 30, a surface of the battery 300 far away from the rear cover of the electronic device 1000 is attached to 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 a circuit board of the electronic device 1000 to supply power to the electronic device 1000.

In the present 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 disposed opposite to each other along the width direction (direction of the illustrated Y-axis) of the housing 100. The frame 20 is further provided with an inner surface 26, and the inner surface 26 and the outer surface 23 are disposed to face away from each other in the thickness direction (direction of the Y axis in the drawing) of the frame 20. The inner side 26 is connected to the first surface 101. The connection between the frame 20 and the middle plate 10 is provided with a undercut, specifically, the connection between the inner side 26 and the first surface 101 is provided with a undercut. In other embodiments, rim 20 is disposed around the perimeter of midplane 10, and the connection between inner side 26 of rim 20 and first surface 101 of midplane 10 is provided with an undercut. The present embodiment is described by taking an example in which the frame includes two sub-frames.

In this embodiment, the inner side 26 of the frame 20 is provided with a groove 27, and the groove 27 is formed by recessing the inner side 26 into the frame 20. The groove 27 is located at the junction of the inner side 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 sidewall of the groove 27. It is also understood that the junction of the first surface 101 and the inner side 26 forms a recess 27. The grooves 27 are formed in the partial frame 20 surrounding the battery compartment 30, that is, the inner side surfaces 26 of the first sub-frame 24 and the second sub-frame 25, and the grooves 27 in the first sub-frame 24 and the grooves 27 in the second sub-frame 25 are arranged opposite to each other. The lengthwise direction of the groove 27 extends along the lengthwise direction (direction of the X-axis shown) of the rim 20. The length of the recess 27 in this embodiment is the same as the length of the battery compartment 30. Referring to fig. 3b and 3c, fig. 3b is a schematic cross-sectional view of one embodiment of a recess of a housing in the electronic device shown in fig. 1, and fig. 3c is a schematic cross-sectional view of another embodiment of a recess of a housing in the electronic device shown in fig. 1. The cross-section of the groove 27 may be rectangular, arc-shaped or trapezoidal in shape along the width direction of the middle plate 10, as shown in fig. 3b and 3 c.

In other embodiments, rim 20 is disposed around the perimeter of midplane 10 and a groove 27 is provided throughout the junction of inner side 26 of rim 20 and first surface 101 of midplane 10. I.e. grooves 27 may be provided around the circumference of the middle plate 10.

Fig. 4a is a schematic cross-sectional view of one embodiment of a projection of a housing in the electronic device shown in fig. 1, fig. 4b is a schematic cross-sectional view of a second embodiment of a projection of a housing in the electronic device shown in fig. 1, and fig. 4c is a schematic cross-sectional view of a third embodiment of a projection of a housing in the electronic device shown in fig. 1, as shown in fig. 4a, 4b and 4 c. In the second embodiment, the connection between the inner side 26 of the frame 20 and the first surface 101 of the middle plate 10 is provided with a protrusion 28, and the protrusion 28 protrudes from the first surface 101 and is connected to the inner side 26 of the frame 20. In this embodiment, the protruding portion 28 is located in the battery compartment 30, specifically, two protruding portions 28 are located at the connection points of 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 4c, the cross-section of the protrusion 28 may be rectangular and inverted trapezoidal in shape along the width direction of the middle plate 10. As shown in fig. 4b, the protruding portion 28 further includes a plane facing away from the first surface 101 and an arc surface connected to the first surface 101 and recessed toward the middle plate 10.

Referring to fig. 5, fig. 5 is a schematic cross-sectional view of a fourth embodiment of a housing in the electronic device of fig. 1. In the fourth embodiment, the housing 100 includes the recess 27 and the projection 28. Specifically, the groove 27 is located at the connection between the inner side 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 26 of the first sub-frame 24. It will be appreciated that the grooves 27 and the projections 28 are disposed opposite each other along the width direction (the direction of the Y axis shown) of the housing 100. Wherein the cross-section of the groove 27 is circular arc-shaped, and the cross-section of the projection 28 is rectangular.

Note that, the undercut portion of any of the above embodiments is formed in the process of etching the middle plate 10 in the form of the groove 27 or the protrusion 28. The etching of the middle plate 10 is to thin the middle plate 10, i.e. the dimension between the first surface 101 and the second surface 102, so as to achieve the light and thin purpose of the housing 100.

In the embodiment of the application, the middle plate 10 and the frame 20 are manufactured by adopting an integrated forming mode and combining an etching process, wherein the thickness t of the middle plate 10 is smaller than 0.3mm. For example, the thickness t of the middle plate 10 may be 0.2mm or more and 0.25mm or less. The thickness of the whole middle plate 10 is thinner, and compared with the thickness reduction of the prior art, the thickness of the middle plate 10 is reduced in the part of the battery compartment 30, so that the light and thin shell 100 can be realized, and the light and thin electronic equipment 1000 can be further realized. Meanwhile, the housing 100 is of an integrally formed structure, so that the dimensional accuracy and structural rigidity of the housing 100 can be ensured, and the flatness of the middle plate 10 can also be ensured. The unreliability of the assembly structure of the middle plate 10 and the frame 20 can be avoided, and the influence on the waterproof performance and the flatness of the whole shell 100 caused by the high-low level difference between the split structures can be avoided; the problem that the screw assembly of the case 100 affects the capacity of the battery 300 during the assembly process can also be avoided.

Referring to fig. 6, fig. 6 is an enlarged schematic view of the first surface 101 of the middle plate 10 and the surface of the undercut shown in fig. 2. The first surface 101 and the side etched portion of the middle plate 10 are formed by etching, the middle plate 10 is made of an aluminum alloy material, and after the etching of the first surface 101 and the side etched portion of the middle plate 10 by a chemical etching solution can be observed through a microscope lens, crystal boundaries are formed by etching, that is, the surfaces of the first surface 101 and the side etched portion have crystal boundary characteristics, and typical crystal grain characteristics are represented, so that the etching can be understood as inorganic processing. The roughness of the first surface 101 of the grain boundary of the present embodiment is 0.5 or more. Alternatively, the surface roughness Ra of the first surface 101 and the undercut formed by etching is 3.41. Among them, a crystal in which the internal lattice directions of the crystals (i.e., the directions of atomic arrangement) are completely identical is called a single crystal; the metal material actually used, even though it has a small volume, still contains many small crystals inside, and these small crystals with substantially the same lattice phase are in the form of particles, so called "grains". In polycrystals, interfaces exist between grains due to the difference in orientation of the grains, and are called grain boundaries. Because of the difference in the orientation of the particle arrangement of the two grains at the grain boundaries, both tend to conform the particle arrangement at the grain boundaries to their orientation. When equilibrium is reached, the atoms at the grain boundaries form a transitional arrangement, and the structure at the grain boundaries is relatively loose due to irregular arrangement of the atoms, so that the grain boundaries also have some characteristics different from those of crystal grains. The atomic arrangement on the grain boundary is loose compared with the grain interior, so that the grain boundary is easy to be exposed after being corroded (hot erosion and chemical corrosion).

Referring to fig. 7, fig. 7 is a flowchart of a method for manufacturing the housing 100 shown in fig. 2, the method for manufacturing the housing 100 includes the following steps,

Referring to fig. 8, fig. 8 is a schematic diagram illustrating a cross-sectional structure of the housing substrate D after the step S1 is performed in fig. 7. Step S1, providing a housing substrate D. The case base material D includes a middle plate base body 10a and a frame base body 20a, the middle plate base body 10a includes a first base surface 101a facing the positive Z-axis direction and a second base surface 102a disposed opposite to the first base surface 101a, and the frame base body 20a is protruded from the edge of the first base surface 101 a. The frame base 20a includes a first basic side frame 201a and a second basic side frame 202a, where the first basic side frame 201a and the second basic side frame 202a each include an inner reference surface 203a, and the inner reference surface 203a is connected to the first basic surface 101 a. The first basic side frame 201a and the second basic side frame 202a form a receiving area with the middle plate base 10 a.

Specifically, step S1 further includes:

providing a metal base material, and processing a reference surface of the metal base material by using a numerical control machine tool (Computer numerical control machine tools, CNC) machining method to obtain a metal machined part. The metal work piece includes a first portion and a second portion. The first portion is a plate-like structure and the second portion is disposed around a periphery of the first portion.

Wherein, the second part is equipped with a plurality of holes of inlaying, inlays and establishes the hole and play the locate function to the nanometer process of moulding plastics. The material of the metal base material can be blank formed by extrusion molding and solution aging heat treatment of 6013 aluminum alloy and 7075 aluminum alloy.

And (3) carrying out injection molding on a metal workpiece (not shown) by adopting a nano injection molding technology, and forming a basic plastic part in the embedded hole of the second part of the metal workpiece to obtain an injection molded part.

And (3) carrying out surface machining treatment on the injection molding by using CNC machining to obtain the shell substrate D. The case base material D includes a middle board base 10a and a frame base 20a. The intermediate plate base 10a includes a first base surface 101a and a second base surface 102a that are disposed opposite to each other, and the first base surface 101a is disposed toward the positive direction of the Z-axis. The bezel base 20a includes a basic side frame. The basic side frame may surround the periphery of the first basic surface 101a, or may be two basic side frames. In the present embodiment, two basic side frames are described as an example, and the two basic side frames are respectively provided on opposite sides of the first basic surface 101a in the width direction, and may be named as a first basic side frame 201a and a second basic side frame 202a.

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

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

Referring to fig. 9, fig. 9 is a schematic diagram illustrating a cross-sectional structure of the housing substrate D after performing step S2 in fig. 7. In step S2, the protective layer 40 is formed on the surface of the case base material D. In this step, the protective layer 40 covers the first base surface 101a, the second base surface 102a, the first base side frame 201a, the second base 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 a coating method. In other embodiments, the protective layer 40 may be formed in other ways using other materials.

Step S3, removing part of the protection layer on the shell substrate D by adopting a laser etching process, and exposing the first basic surface 101a and part of the two inner side reference surfaces 203a. Referring to fig. 10, fig. 10 is a schematic diagram illustrating a cross-sectional structure of the housing substrate D after performing step S3 in fig. 7. In this step, the protective layer 40 of the first base surface 101a and the protective layer 40 at the junction of the first base 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 shell second matrix E; wherein, the middle plate base 10a forms a second middle plate base 10b, and side etching parts are formed on part of two inner side reference surfaces 203 a. As shown in fig. 11, fig. 11 is a schematic diagram showing a sectional structure of the second base E of the case after step S4 is performed in fig. 7. The first base surface 101a is etched along the thickness direction (direction of the illustrated Z-axis) of the midplane substrate 10a to remove a portion of the material in the thickness direction (direction of the illustrated Z-axis) of the midplane substrate 10a to form a second midplane substrate 10b. The first base surface 101a is etched to form a third base surface 101b. Wherein the thickness t of the second middle plate base material 10b along the Z-axis direction is 0.2mm-0.25mm.

In the step, chemical etchant is used for etching, and when 6013 aluminum alloy or 7075 aluminum alloy is adopted as the material of the metal base material, the thickness t of the middle plate base body 10a along the Z-axis direction is etched to 0.25mm;

in other embodiments, the metal substrate may be a particle reinforced aluminum matrix composite. 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 0.2mm because the particle-reinforced aluminum-based composite material has a higher elastic modulus and a better strength.

In this step, the first base surface 101a is etched by the chemical etching solution, and at the same time, an undercut is formed at the junction between the first base surface 101a and the two inner reference surfaces 203 a. It can be appreciated that the inner reference surface 203a is etched to form a second inner reference surface 203b, and the undercut is located at the connection between the second inner reference surface 203b and the third base surface 101b, and the frame base 20a is etched to form a frame second frame base 20b. The first surface 101 formed by etching and the material surface of the side etched portion in this embodiment of the method exhibit typical equiaxed crystal characteristics, and the surface roughness Ra is 3.41.

Undercut is the groove 27, the projection 28 or a combination of the groove 27 and the projection 28 in fig. 3a, 3b, 3c and fig. 4a, 4b, 4 c. The cross-sectional shape of the groove 27 may be rectangular, arc-shaped or trapezoidal. The cross-sectional shape of the projection 28 may be rectangular or inverted trapezoidal. As shown in fig. 4b, the cross-section of the projection 28 is shaped as a plane facing away from the first surface 101 and as an arc-shaped surface connecting the first surface.

And S5, removing the protective layer on the second substrate E of the shell. Specifically, the protective layer 40 masked on the surface of the second substrate E of the case is cleaned using a chemical lotion.

Step S6, carrying out surface appearance process treatment on the second substrate E of the shell to form the shell 100. In the present method, only the frames 20 on both sides of the middle plate 10 are described as an example, and the frames 20 on both sides of the middle plate are actually processed to form the undercut portions.

Please refer to fig. 3a, 3b and 3c again. Wherein the second midplane substrate 10b forms the midplane 10, the third base surface 101b forms the first surface 101, the second base surface 102a forms the second surface 102, and the second bezel substrate 20b forms the bezel 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 adopted 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, so that the appearance of the second substrate E of the shell is brighter, finer and smoother; then, the surface of the second substrate E of the shell is treated by adopting an anodic oxidation method, so that an oxide film is formed on the surface of the second substrate E of the shell, and further the corrosion resistance, hardness, wear resistance, insulativity, heat resistance and the like of the surface of the second substrate E of the shell are greatly improved; finally, the processes of blanking, laser carving and the like are performed, waste materials on the surface of the second substrate E of the shell are removed, and certain dryness of the surface of the second substrate E of the shell is guaranteed to form the shell 100. It should be noted that, after the polishing anodic oxidation method is performed, the thickness of the middle plate 10 is increased or decreased by a negligible amount, which is also understood to be 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 application, the frame 20 and the middle plate 10 of the shell 100 are integrally formed by adopting aluminum alloy, so that the technical problems of flatness, waterproofness and stability of assembly precision in the split type shell (the split of part of the middle plate and the middle plate corresponding to the position of the battery compartment or the split of the middle plate and the frame) in the prior art are solved, and processing stress is not generated in the etching processing process, so that the strength of the shell is improved. In addition, the processing cost of the shell 100 is reduced; compared with the process limitation of CNC processing to form the middle plate, the embodiment adopts the etching mode to process the middle plate 10, so that the processing precision can be improved, the thickness of the middle plate 10 is further thinned, and the partial or total thinning of the middle plate 10 is realized.

Referring to fig. 12, fig. 12 is a surface microtopography of a prior art midplane. It can be observed through the test lens that the machined surface has obvious tool marks, the surface roughness Ra is 0.36, the thickness of the middle plate is reduced through CNC machining of the middle plate, and in practice, the middle plate can only be kept at 0.3mm or more, if the thickness is continuously reduced, the stress of the middle plate can not be reduced through CNC machining, or even the middle plate is broken and deformed.

The foregoing has outlined rather broadly the more detailed description of embodiments of the application, wherein the principles and embodiments of the application are explained in detail using specific examples, the above examples being provided solely to facilitate the understanding of the method and core concepts of the application; meanwhile, as those skilled in the art will have variations in the specific embodiments and application scope in accordance with the ideas of the present application, the present description should not be construed as limiting the present application in view of the above.

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 which is arranged opposite to the first surface,

The middle plate and the frame are integrally formed, the frame is arranged at the edge of the first surface,

The first surface has grain boundaries.

2. The housing of claim 1, wherein the roughness of the first surface is 0.5 or greater.

3. The housing of claim 1, wherein the rim includes an inner side surface, and wherein an undercut is formed at a junction of the inner side surface and the first surface.

4. The housing of claim 1, wherein the thickness of the middle plate is 0.2mm or more and 0.3mm or less.

5. The housing of claim 1, wherein the material of the housing is 6013 aluminum alloy or 7075 aluminum alloy, and the thickness of the middle plate is 0.25mm.

6. The housing of claim 1, wherein the material of the housing is a particle reinforced aluminum matrix composite material and the thickness of the middle plate is 0.2mm.

7. A housing according to claim 3, wherein the undercut surface has grain boundaries.

8. A housing according to claim 3, wherein the undercut is a groove recessed in the inner side surface and the first surface, and the cross-section of the groove is rectangular, arc-shaped or trapezoidal in shape along the width direction of the middle plate.

9. A housing according to claim 3, wherein the undercut is a projection projecting from the first surface and connected to the inner side surface, and a cross-section of the projection is rectangular, inverted trapezoidal in shape along a width direction of the middle plate; or the convex part comprises a plane facing away from the first surface and an arc-shaped surface which is connected with the first surface and concavely arranged towards the middle plate.

10. A method of manufacturing a housing, the method comprising:

providing a shell substrate, wherein the shell substrate comprises a middle plate substrate and a frame substrate, the middle plate substrate comprises a first basic surface and a second basic surface which is opposite to the first basic surface, the frame substrate is convexly arranged at the edge of the first basic surface, the frame substrate comprises basic side frames, and the basic side frames comprise inner side reference surfaces;

Forming a protective layer on the surface of the shell base material;

Removing part of the protective layer on the shell substrate by adopting a laser etching process, and exposing the first basic surface and part of the inner side reference surface;

Etching the shell substrate through an etching process to obtain a shell second substrate, wherein 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 is provided with a grain boundary;

And removing the protective layer.

11. The method of claim 10, further comprising performing a cosmetic process on the second substrate of the housing.

12. The method of claim 10, wherein the housing substrate is made of 6013 aluminum alloy or 7075 aluminum alloy, and the thickness of the second middle plate substrate is 0.25mm after the housing substrate is etched.

13. The method of claim 10, wherein the shell substrate is a particle reinforced aluminum matrix composite material and the second middle plate substrate has a thickness of 0.2mm.

14. The method of claim 10, wherein the undercut is a convex structure or a concave structure.

15. The method according to claim 10, wherein in the step of etching the housing base material by an etching process, a undercut is formed at a junction between the inner reference surface and the third base surface after etching; the undercut has grain boundaries on its surface.

16. The housing of claim 10, wherein the roughness of the first surface is 0.5 or greater.

17. An electronic device comprising a housing according to any one of claims 1-9 and a battery, said housing comprising a battery compartment, said middle plate being a bottom wall of the battery compartment, said battery being mounted to said battery compartment.