Camera decorative part, method for preparing camera decorative part and electronic device

Abstract

The present application provides a structural component, a method for preparing the structural component, and an electronic device. The structural component includes a substrate and a metal coating layer, the substrate includes an outer surface, and the metal coating layer is arranged on the outer surface, wherein the substrate is made of a polymer material having a polar group, the thermal deformation temperature of the polymer material is greater than or equal to 175°C, and the thermal expansion coefficient of the polymer material is less than or equal to 60*10 ‑6 / K. In the structural part shown in the present application, the substrate is made of a polymer material having polar groups. The polar groups of the polymer material help to form a strong bonding force with the metal coating layer. The metal coating layer can be directly formed on the outer surface of the substrate without the need to design a base layer between the metal coating layer and the outer surface, which simplifies the preparation process of the structural part and improves the production efficiency of the structural part.

Description

Technical Field

[0001] The present application relates to the technical field of electronic equipment, and in particular to a structural component, a method for preparing the structural component, and an electronic device. Background Art

[0002] With the continuous development of science and technology, mobile phones and other electronic devices are widely used in people's daily life and work, and have become indispensable daily necessities. In current electronic devices, structural parts are often treated with primer on the surface of the substrate and then plated to achieve a metal-like effect to improve the appearance of the structural parts, which makes the preparation process of the structural parts complicated and reduces the production efficiency of the structural parts. Summary of the invention

[0003] The present application provides a structural component, a method for preparing the structural component, and an electronic device, which simplifies the preparation process of the structural component and improves the production efficiency of the structural component.

[0004] In a first aspect, the present application provides a structural part, comprising a substrate and a metal coating layer, wherein the substrate comprises an outer surface, and the metal coating layer is disposed on the outer surface, wherein the substrate is made of a polymer material having a polar group, the thermal deformation temperature of the polymer material is greater than or equal to 175°C, and the thermal expansion coefficient of the polymer material is less than or equal to 60*10 -6 / K.

[0005] In the structural part shown in the present application, the substrate is made of a polymer material with polar groups. The polymer material has a high thermal deformation temperature and a low thermal expansion coefficient. The polar groups of the polymer material can form a strong binding force with the metal atoms of the metal coating layer. The binding force between the substrate and the metal coating layer is strong. Therefore, the metal coating layer can be directly formed on the outer surface of the substrate without designing a primer layer between the metal coating layer and the outer surface, which simplifies the preparation process of the structural part and improves the production efficiency of the structural part. Moreover, since there is no need to spray to form a primer layer, there is no need to use a large amount of solvent in the preparation process of the structural part, which reduces the pollution caused in the preparation process of the structural part.

[0006] In addition, during the formation of the metal coating layer, since the polymer material has good heat resistance, the substrate will not be thermally deformed, which not only helps the formation of the metal coating layer, improves the bonding force between the substrate and the metal coating layer, ensures the quality of the metal coating layer, but also effectively improves the yield of the structural parts. Moreover, during the formation of the metal coating layer, the ambient temperature of the substrate where the metal coating layer is formed will go through a process from low temperature (such as room temperature) to high temperature (such as the temperature at which metal coating can be performed) and then to low temperature (such as the temperature after cooling). Since the polymer material has a low thermal expansion coefficient, the substrate will not expand or contract significantly, which helps to improve the quality of the metal coating layer and ensure the reliability of the structural parts.

[0007] Moreover, since the thermal expansion coefficient of the metal coating layer is 5*10 -6 / K to 25*10 -6 / K, the lower thermal expansion coefficient of the polymer material can not only make the difference in thermal expansion coefficient between the substrate and the metal coating layer smaller, but also when the structural parts are used in high or low temperature environments, the deformation difference between the substrate and the metal coating layer will not be too large, which not only helps to improve the structural stability between the substrate and the metal coating layer, but also can avoid cracking of the metal coating layer.

[0008] Among them, the test of the heat deformation temperature of polymer materials meets the international standard ISO 75-1 / -2, and the test of the thermal expansion coefficient of polymer materials meets the international standard ISO 11359.

[0009] In one embodiment, the flow rate of the polymer material weighing 2.16 kg at 350° C. is greater than or equal to 22 g / 10 min. The test of the fluidity of the polymer material meets the international standard ISO 1133. That is, the polymer material has high fluidity. In other words, the polymer material used in the substrate has a high melt index and high fluidity, which not only helps to obtain a high-quality outer surface when the substrate is formed by injection molding, but also helps to achieve high-precision molding of the substrate, and can reduce other appearance defects such as weld marks of the substrate.

[0010] In one embodiment, the mirror effect grade of the outer surface of the substrate is less than or equal to A3, and the outer surface roughness of the substrate is less than or equal to 0.06 μm. In other words, the outer surface quality of the substrate is high, which helps to improve the bonding strength between the substrate and the metal coating layer.

[0011] In one embodiment, the surface hardness of the outer surface of the substrate is greater than or equal to F, that is, the outer surface of the substrate has a higher surface hardness, which not only helps to reduce scratches on the substrate, but also prevents cracking of the metal coating layer.

[0012] In one embodiment, the notched impact strength of the substrate is greater than or equal to 4 kJ / m 2 Among them, the notched impact strength test of the substrate meets the international standard ISO 180. The substrate has high impact strength, which helps to improve the toughness and impact strength of the structural parts and improve the reliability of the structural parts.

[0013] In one embodiment, the flexural modulus of the substrate is greater than or equal to 2500 MPa. The flexural modulus of the substrate meets the international standard ISO 178. The substrate has a high modulus, which not only helps to improve the strength and rigidity of the structural member, but also allows the metal coating layer to be directly formed on the outer surface of the substrate without designing a base layer.

[0014] In one embodiment, the outer surface is provided with a texture pattern, the texture pattern includes a plurality of texture pattern units, and the metal coating layer covers the texture pattern. Exemplarily, the cross section of each texture pattern unit is triangular. Since the metal coating layer can be directly formed on the outer surface, there is no bottom layer accumulated at the sharp corner position between two adjacent texture pattern units, and the sharp corner position of each texture pattern unit will not be changed, which helps to improve the metal texture of the structural part.

[0015] In one embodiment, the polar group is an imide group, a sulfone group, a diphenylsulfone group or a phthalamide group, wherein the polar group has high temperature resistance.

[0016] In one embodiment, the polymer material includes at least one of polyetherimide, polysulfone plastic, polyethersulfone, polyphenylene sulfone resin and polyphthalamide, wherein the polymer material complies with the international standard ISO 75-1 / -2.

[0017] In one embodiment, the substrate does not contain weld lines.

[0018] In one embodiment, the material of the metal coating layer includes at least one of titanium, chromium, tungsten, vanadium, niobium, zirconium, hafnium, titanium carbide and tungsten carbide.

[0019] In one embodiment, the thickness of the metal coating layer is between 0.2 μm and 8 μm.

[0020] In one embodiment, the pencil hardness of the metal coating layer is ≥2H, and the adhesion of the metal coating layer is ≥4B. The metal coating layer not only has a high-quality metal effect, but also can obtain different colors by selecting different metal materials, which helps to realize the personalized design of the structural parts. Among them, the adhesion of the metal coating layer is measured by a hundred-grid test.

[0021] In a second aspect, the present application provides an electronic device, comprising a housing and any one of the above-mentioned structural components, wherein the structural component is mounted on the housing.

[0022] In the electronic device shown in the present application, the substrate of the structural part is made of a polymer material with polar groups. The polar groups of the polymer material help to form a strong bonding force with the metal coating layer. The metal coating layer can be directly formed on the outer surface of the substrate without the need to design a primer layer between the metal coating layer and the outer surface, which simplifies the preparation process of the structural part and improves the production efficiency of the structural part. Moreover, since there is no need to spray to form the primer layer, there is no need to use a large amount of solvent in the preparation process of the structural part, which reduces the pollution caused by the preparation process of the structural part.

[0023] In one embodiment, the structural member is a button, a card holder or a decorative member.

[0024] In one embodiment, the housing has the same structure as the structural member.

[0025] In a third aspect, the present application provides a method for preparing a structural part, comprising:

[0026] The polymer material with polar groups is injection molded to form a substrate, the thermal deformation temperature of the polymer material is greater than or equal to 175°C, and the thermal expansion coefficient of the polymer material is less than or equal to 60*10 -6 / K, wherein the substrate comprises an outer surface;

[0027] A metal plating film is formed on the outer surface.

[0028] In the preparation method of the structural part shown in the present application, a metal coating layer is directly formed on the outer surface of the substrate. This method can easily prepare a highly refined structural part with a metal-like appearance effect. The structural part has high gloss, good flatness, excellent reliability, strong product performance, low cost and light weight. The metal coating layer and the substrate are firmly bonded, have excellent wear resistance, and are not easy to crack or fall off. The structural part prepared by this method has both exquisite appearance and light weight, and the product has strong performance. Moreover, the structural part prepared by this method has high strength, good toughness, good dimensional stability, and excellent chemical resistance.

[0029] In one embodiment, in the step of forming a metal coating on the outer surface, the metal coating is formed by a physical vapor deposition process. Exemplarily, the metal coating layer is formed by a high-temperature sputtering coating process. Not only is the metal coating layer of high purity and good density, but also the bonding force with the substrate is strong, which helps to improve the reliability of the structural parts. In addition, compared with the conventional vacuum non-conductive coating process used to form the metal coating layer, the high-temperature sputtering coating process is simpler and pollution-free. Furthermore, the non-conductive vacuum coating process is often used for the surface decoration of glass-filled polycarbonate resin parts. The use of the physical vapor deposition process can save three spraying steps. In particular, the parts using the non-conductive vacuum coating are prone to resin accumulation and fat edges, which is not conducive to achieving high-quality metallization effects.

[0030] In one embodiment, in the step of injection molding a polymer material having polar groups to form a substrate, the mold temperature of the injection mold is between 135°C and 170°C, the temperature of the polymer material is between 330°C and 400°C, the injection pressure of the polymer material into the injection mold is between 700 bar and 1500 bar, and the injection speed is greater than or equal to 20 mm / s to improve the surface quality of the substrate.

[0031] In one embodiment, the polymer material is injected into the injection mold by a single-point injection method, which helps to reduce appearance defects such as weld lines on the outer surface of the substrate and improve the surface quality of the substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solution of the embodiment of the present application, the drawings required for use in the embodiment of the present application will be described below.

[0033] Figure 1 It is a structural schematic diagram of an electronic device provided in an embodiment of the present application;

[0034] Figure 2 yes Figure 1 A schematic diagram of the back structure of the electronic device shown;

[0035] Figure 3 yes Figure 2 A schematic cross-sectional structure diagram of a structural component in the electronic device shown in the first embodiment;

[0036] Figure 4 yes Figure 3 An enlarged structural diagram of region A in the structural member shown;

[0037] Figure 5 yes Figure 2 A schematic cross-sectional structure diagram of a structural component in the electronic device shown in the second embodiment;

[0038] Figure 6 yes Figure 5 An enlarged structural diagram of area B in the structural member shown;

[0039] Figure 7 yes Figure 2 A schematic cross-sectional structure diagram of a structural component in the electronic device shown in the third embodiment;

[0040] Figure 8 yes Figure 2 A schematic cross-sectional structure diagram of a structural component in the electronic device shown in the fourth embodiment;

[0041] Fig. 9 It is a process flow chart of a method for preparing a structural part provided in an embodiment of the present application. DETAILED DESCRIPTION

[0042] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

[0043] See also Figure 1 and Figure 2 , Figure 1 is a structural diagram of an electronic device 1000 provided in an embodiment of the present application, Figure 2 yes Figure 1 A schematic diagram of the back structure of the electronic device 1000 is shown.

[0044] The electronic device 1000 may be an electronic product such as a mobile phone, a tablet computer, a laptop computer, a car computer, a smart watch, a smart bracelet, a POS (point of sales terminal) or the like. Next, the embodiment of the present application is described by taking the electronic device 1000 as a mobile phone as an example. For the convenience of description, the width direction of the electronic device 1000 is defined as the X-axis direction, the length direction of the electronic device 1000 is defined as the Y-axis direction, and the thickness direction of the electronic device 1000 is defined as the Z-axis direction. The X-axis direction, the Y-axis direction, and the Z-axis direction are perpendicular to each other.

[0045] The electronic device 1000 includes a housing 100, a display module 200, a circuit board 300, a processor (not shown), a camera module 400, a button 500, a card tray 600 and a decorative piece 700. The display module 200, the circuit board 300, the processor, the camera module 400, the button 500, the card tray 600 and the decorative piece 700 are all installed on the housing 100.

[0046] The housing 100 includes a frame 110 and a back cover 120, and the back cover 120 is mounted on the frame 110. The frame 110 may be a middle frame of the electronic device 1000, and the back cover 120 may be a battery cover of the electronic device 1000. In some other embodiments, the frame 110 may also be other structural members in the electronic device 1000 for supporting.

[0047] The frame 110 is provided with a button hole 1101 and a card holder hole 1102. The openings of the button hole 1101 and the card holder hole 1102 are both located on the peripheral surface of the frame 110 (not marked in the figure). The button hole 1101 and the card holder hole 1102 are both recessed from the peripheral surface of the frame 110 toward the inner side of the frame 110, and penetrate the frame 110 to connect the inner side and the outer side of the frame 110. Among them, the button hole 1101 is located on the left side of the frame 110, and the card holder hole 1102 is located on the bottom side of the frame 110. In some other embodiments, the button hole 1101 may also be located on the right side, top side or bottom side of the frame 110, and / or, the card holder hole 1102 may also be located on the top side, left side or right side of the frame 110.

[0048] It should be noted that the directional terms such as "top", "bottom", "upper", "lower", "left" and "right" involved in this application are referenced to the attached Figure 1 The description of the orientation shown, with the positive direction of the Y-axis as the "top", the negative direction of the Y-axis as the "bottom", the positive direction of the Z-axis as the "up", the negative direction of the Z-axis as the "down", the positive direction of the X-axis as the "right", and the negative direction of the X-axis as the "left", 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 should not be understood as a limitation on the present application.

[0049] The back cover 120 is mounted on one side of the frame 110. Exemplarily, the back cover 120 can be mounted on the frame 110 in a detachable manner to facilitate the repair and replacement of internal components or modules of the electronic device 1000. The back cover 120 is provided with an avoidance hole (not shown), which is located on the top side of the back cover 120. The opening of the avoidance hole is located on the upper surface of the back cover 120 (not marked in the figure). The avoidance hole is recessed in the direction (negative direction of the Z axis in the figure) from the upper surface of the back cover 120 to the lower surface (not marked in the figure), and passes through the lower surface of the back cover 120. That is, the avoidance hole passes through the back cover 120 along the thickness direction of the back cover 120.

[0050] The display module 200 is installed on one side of the housing 100. Specifically, the display module 200 is installed on the other side of the frame 110. That is, the display module 200 is installed on the side of the frame 110 away from the back cover 120. That is, the display module 200 and the back cover 120 are respectively installed on opposite sides of the frame 110. When the user uses the electronic device 1000, the display module 200 is placed toward the user, and the back cover 120 is placed away from the user. Among them, the display module 200 can be a display screen such as LCD (liquid crystal display) or OLED (organic light-emitting diode), and is used to display information such as images or text.

[0051] The circuit board 300, the processor and the camera module 400 are all installed on the inner side of the housing 100. The processor can be installed on the circuit board 300 and electrically connected to the circuit board 300. Among them, the circuit board 300 can be the mainboard of the electronic device 1000, and the processor can be the CPU (central processing unit) of the electronic device 1000. The camera module 400 is installed on the top side of the housing 100 and is electrically connected to the circuit board 300 to achieve electrical connection with the processor. Among them, the camera module 400 can be used as a rear camera module of the electronic device 1000, and the camera surface (not shown) of the camera module 400 can be exposed relative to the avoidance hole of the back cover 120. The camera module 400 can receive the information acquisition signal sent by the processor through the circuit board 300, and collect the light outside the electronic device 1000 through the camera surface to form corresponding image data.

[0052] The button 500 and the card tray 600 are both installed in the frame 110. Specifically, the button 500 is installed in the button hole 1101, and the card tray 600 is installed in the card tray hole 1102. Among them, the button 500 can be a function button such as a power button, a volume button or a lock screen button of the electronic device 1000, and the card tray 600 can carry a SIM card (Subscriber Identity Module) or a TF card (Trans-flash Card).

[0053] In this embodiment, the decorative piece 700 may be a camera decorative piece. The decorative piece 700 is mounted on the back cover 120 and covers the camera module 400, which can not only protect the camera module 400, but also improve the appearance of the electronic device 1000. Exemplarily, the decorative piece 700 is in a circular shape. In some other embodiments, the decorative piece 700 may also be other decorative pieces of the electronic device 1000, for example, the decorative piece 700 may be a receiver decorative piece, and the decorative piece 700 is mounted on the receiver hole of the frame 110.

[0054] It is understandable that the housing 100, the button 500, the card tray 600 and the decorative part 700 are all structural parts 800 of the electronic device 1000, and all have an impact on the appearance of the electronic device 1000. Therefore, in the preparation process of the structural part 800, a metal plating layer is often formed by a coating process to achieve a metal-like effect, so as to improve the appearance of the electronic device 1000. Next, taking the decorative part 700 as an example, the structural part 800 of the electronic device 1000 is described in detail.

[0055] See also Figure 3 and Figure 4 , Figure 3 yes Figure 2The cross-sectional structure diagram of the structural component 800a in the electronic device 1000 in the first embodiment is shown. Figure 4 yes Figure 3 An enlarged structural diagram of region A in the structural member 800a is shown.

[0056] In this embodiment, the structural member 800a includes a substrate 10a, a base layer 20a and a metal coating layer 30a. The substrate 10a includes an outer surface 101a, the base layer 20a is arranged on the outer surface 101a, and the metal coating layer 30a is arranged on the surface of the base layer 20a away from the outer surface 101a. Specifically, the outer surface 101a is provided with a texture pattern, the texture pattern includes a plurality of texture pattern units 12a, and the base layer 20a covers the plurality of texture pattern units 12a. Exemplarily, each texture pattern unit 12a is in the shape of a quadrangular pyramid, and the cross section of each texture pattern unit 12a is triangular. It should be noted that the texture pattern is a part of the substrate 10a, and the texture pattern is formed by performing a shape process on the outer surface 101a of the substrate 10a.

[0057] The substrate 10a is made of conventional engineering plastics. For example, the conventional engineering plastics may be one or more of polycarbonate (PC), polyacrylic acid (PA), acrylonitrile-butadiene-styrene (ABS), and a composite of polycarbonate and acrylonitrile-butadiene-styrene.

[0058] It should be noted that in the above embodiment, based on the characteristics of conventional engineering plastics, conventional engineering plastics have no polar groups and have a high thermal expansion coefficient. The conventional engineering plastics have poor bonding strength with the metal atoms of the metal coating layer 30a. When the metal coating layer 30a is formed on the outer surface 101a of the substrate 10a, the adhesion of the metal coating layer 30a is poor. The metal coating layer 30a affects the reliability of the structural part 800a. Therefore, it is often necessary to first perform primer treatment on the outer surface 101a of the substrate 10a to form a base layer 20a, and then use a non-conductive vacuum metallization (NCVM) process to form the metal coating layer 30a on the surface of the base layer 20a away from the substrate 10a. The preparation process of the structural part 800a is complicated, the production efficiency is low, and in the process of spraying to form the base layer 20a, a large amount of solvent is required, which causes great pollution. In addition, since the base layer 20a is often formed by solidifying a liquid resin, and due to the good fluidity of the liquid resin, it will accumulate at the sharp corner position S1a between two adjacent texture pattern units 12a, resulting in resin accumulation, and the sharp corner position S2a of the texture pattern unit 12a will produce a stiffness, etc. After the liquid resin is subsequently solidified to form the base layer 20a, the base layer 20a will reduce the metal texture of the structural component 800a.

[0059] It should be understood that when the structural member 800a is used in an electronic device, the outer surface 101a of the substrate 10a is the surface of the substrate 10a facing the outside of the electronic device 1000, that is, the outer surface 101a of the substrate 10a is the surface of the substrate 10a facing away from the inside of the electronic device 1000, and the description of the "outer surface" in the present application document can be understood in the same way.

[0060] See also Figure 5 and Figure 6 , Figure 5 yes Figure 2 The cross-sectional structure diagram of the structural component 800 in the electronic device 1000 in the second embodiment is shown. Figure 6 yes Figure 5 An enlarged structural diagram of region B in the structural member 800 is shown.

[0061] The structural member 800 includes a substrate 10 and a metal coating layer 20. The substrate 10 includes an outer surface 101, and the metal coating layer 20 is disposed on the outer surface 101. Specifically, the outer surface 101 is provided with a texture pattern, and the texture pattern includes a plurality of texture pattern units 12, and the metal coating layer 20 covers the texture pattern. In this embodiment, the substrate 10 is made of a polymer material having a polar group. Among them, the polar group has high temperature resistance, and the polar group can be an imide group, a sulfone group, a diphenyl sulfone group, or a phthalamide group. It should be noted that in some other embodiments, the substrate 10 may not include the texture pattern unit 12, and the present application does not make any specific restrictions on this.

[0062] Among them, the polymer material is special engineering plastics, and the special engineering plastics can be at least one of polyetherimide (PEI, Polyetherimide), polysulfone (PSU, Polysulfone) plastics, polyethersulfone (Polyethersulfone, PES), polyphenylene sulfone resin (PPSU, Polyphenylene sulfone resins) and polyphthalamide (PPA, Polyphthalamide).

[0063] It should be noted that the substrate 10 is made of non-crystalline special engineering plastics, and the polar groups of the special engineering plastics can form a strong bonding force with the metal coating layer 20. The bonding force between the substrate 10 and the metal coating layer 20 is relatively strong, so the metal coating layer 20 can be directly formed on the outer surface 101 of the substrate 10, without the need to design a primer layer between the metal coating layer 20 and the outer surface 101, which not only simplifies the preparation process of the structural part 800 and improves the production efficiency of the structural part 800, but also does not require spraying to form a primer layer, and does not require a large amount of solvent to be used in the preparation process of the structural part 800, thereby reducing the pollution caused in the preparation process of the structural part 800. In addition, since the metal coating layer 20 can be directly formed on the outer surface 101, there is no primer layer accumulated at the sharp corner position S1 between two adjacent texture pattern units 12, and the sharp corner position S2 of the texture pattern unit 12 will not change, which helps to improve the metal texture of the structural part 800.

[0064] When the polymer material weighing 2.16 kg is at a temperature of 350 degrees Celsius, the flow rate of the polymer material is greater than or equal to 22 g / min. Among them, the fluidity test of the polymer material used in the substrate 10 meets the international standard ISO 1133. In other words, the polymer material used in the substrate 10 has a high melt index and high flow. When the substrate 10 is formed by injection molding, it not only helps to obtain a high-quality outer surface, but also helps to achieve high-precision molding of the substrate 10, and can reduce other appearance defects such as weld marks of the substrate 10. It can be understood that the fluidity of the polymer material can be adjusted by controlling the molecular weight and adding plasticizers.

[0065] The heat deformation temperature of the polymer material used in the substrate 10 is greater than or equal to 175 degrees Celsius. Among them, the heat deformation temperature test of the polymer material used in the substrate 10 meets the international standard ISO 75-1 / -2. In other words, the polymer material used in the substrate 10 has high heat resistance. When the polymer material is used to form the substrate 10 by injection molding, high-temperature and high-speed injection molding can be performed to obtain a substrate 10 with high surface quality, and the good heat resistance is helpful for the substrate 10 to form a metal coating layer 20 by high-temperature sputtering coating in the later stage. Moreover, in the process of forming the metal coating layer 20, due to the high heat resistance of the polymer material, the substrate 10 will not be thermally deformed, not only the metal coating layer 20 can be better formed on the outer surface 101, the bonding force between the substrate 10 and the metal coating layer 20 is improved, the quality of the metal coating layer 20 can be guaranteed, and it also helps to improve the yield of the metal coating layer 20. Among them, the mirror effect grade of the outer surface of the substrate 10 is less than or equal to A3, and the roughness Ra is less than or equal to 0.06μm. The high surface quality of the substrate 10 helps to improve the bonding force between the substrate 10 and the metal coating layer 20 .

[0066] In addition, the surface hardness of the outer surface of the substrate 10 is greater than or equal to F, that is, the outer surface of the substrate 10 has a higher surface hardness, which not only helps to reduce scratches on the substrate 10, but also avoids cracking of the metal coating layer 20. It should be noted that the notched impact strength of the substrate 10 is greater than or equal to 4kJ / m2. Among them, the notched impact strength test of the substrate 10 meets the international standard ISO 180. The substrate 10 has a higher impact strength, which helps to improve the toughness and impact strength of the structural part 800 and improve the reliability of the structural part 800. The flexural modulus of the substrate 10 is greater than or equal to 2500MPa. Among them, the flexural modulus test of the substrate 10 meets the international standard ISO 178. The substrate 10 has a high modulus, which not only helps to improve the strength and rigidity of the structural part 800, but also allows the metal coating layer 20 to be directly formed on the outer surface 101 of the substrate 10 without designing a base layer.

[0067] The thermal expansion coefficient of polymer materials is less than or equal to 60*10 -6 / K. Among them, the test of the thermal expansion coefficient of the polymer material meets the international standard ISO 11359. The thermal expansion coefficient of the polymer material is relatively low. It should be noted that during the formation of the metal coating layer 20, the ambient temperature of the substrate 10 where the metal coating layer 20 is formed will experience a process from low temperature (such as room temperature) to high temperature (such as the temperature at which metal coating can be performed) and then to low temperature (such as the temperature after cooling). Due to the low thermal expansion coefficient of the polymer material, the substrate 10 will not expand or contract significantly, which helps to improve the quality of the metal coating layer 20 and ensure the reliability of the structural component 800. In addition. Since the thermal expansion coefficient of the metal coating layer 20 is 5*10 -6 / K to 25*10 -6 / K, the lower thermal expansion coefficient of the polymer material can not only make the difference in thermal expansion coefficient between the substrate 10 and the metal coating layer 20 smaller, but also when the structural part 800 is used in a high temperature or low temperature environment, the deformation difference between the substrate 10 and the metal coating layer 20 will not be too large, which helps to improve the structural stability between the substrate 10 and the metal coating layer 20 and avoid cracking of the metal coating layer 20.

[0068] In this embodiment, the material of the metal coating layer 20 includes at least one of titanium, chromium, tungsten, vanadium, niobium, zirconium, hafnium, titanium carbide and tungsten carbide. The thickness of the metal coating layer is between 0.2 μm and 8 μm, the pencil hardness test is ≥2H, and the adhesion is ≥4B. The metal coating layer 20 not only has a high-quality metal effect, such as imitating the texture of stainless steel, but also can obtain different colors by selecting different metal materials, which is helpful to realize the personalized design of the structural part 800. The adhesion of the metal coating layer 20 is measured by a hundred-grid test.

[0069] See also Figure 7 , Figure 7 yes Figure 2 The cross-sectional structure diagram of the structural component 800 in the electronic device 1000 in the third implementation manner is shown.

[0070] The difference between the structural member 800 shown in this embodiment and the structural member 800 shown in the second embodiment is that the structural member 800 further includes a topcoat layer 30, which is disposed on the surface of the metal coating layer 20 away from the substrate 10. The topcoat layer 30 can not only protect the metal coating layer 20 and the substrate 10, but also play a decorative role, thereby improving the appearance of the structural member 800.

[0071] See also Figure 8 , Figure 8 yes Figure 2 The cross-sectional structure diagram of the structural component 800 in the electronic device 1000 in the fourth implementation manner is shown.

[0072] The difference between the structural component 800 shown in this embodiment and the structural component 800 shown in the third embodiment is that the structural component 800 can also include a color paint layer 40, which is arranged on the surface of the metal coating layer 20 away from the substrate 10, and the topcoat layer 30 is arranged on the surface of the color paint layer away from the metal coating layer 20.

[0073] In the electronic device 1000 shown in this embodiment, the substrate 10 of the structural component 800 is made of a polymer material having polar groups. The polymer material has high heat resistance and a low thermal expansion coefficient. A metal plating layer 20 can be directly formed on the outer surface 101 of the substrate 10 to achieve an appearance comparable to that of metal, such as an appearance imitating stainless steel, without the need to design a base layer. This not only simplifies the preparation process of the structural component 800 and improves the production efficiency of the structural component 800, but also reduces the production cost of the structural component 800 and the weight of the structural component 800.

[0074] See also Fig. 9 , Fig. 9 It is a process flow chart of a method for preparing a structural part provided in an embodiment of the present application.

[0075] The present application provides a method for preparing a structural component, which is used to prepare the structural component 800. The method for preparing the structural component includes step S1 and step S2.

[0076] Step S1, injection molding a polymer material having polar groups to form a substrate 10. The thermal deformation temperature of the polymer material is greater than or equal to 175°C, and the thermal expansion coefficient of the polymer material is less than or equal to 60*10 -6 / K, the substrate 10 includes an outer surface 101. In this embodiment, the outer surface 101 is provided with a texture pattern, and the texture pattern includes a plurality of texture pattern units 12. Exemplarily, the texture pattern unit 12 is in the shape of a quadrangular pyramid, and the cross section of the texture pattern unit 12 is triangular. Wherein, the polymer material can be plastic particles. Exemplarily, the polymer material is a special engineering plastic, and the special engineering plastic can be at least one of polyetherimide, polysulfone plastic, polyethersulfone, polyphenylene sulfone resin and polyphthalamide.

[0077] Specifically, the polymer material is melted and plasticized and then injected into a plastic structural part mold, and high-temperature and high-speed injection molding is performed to obtain a substrate 10 with high surface quality. The substrate 10 does not have a weld line. The thickness of the substrate 10 is greater than or equal to 0.35 mm, the mirror effect grade of the outer surface of the substrate 10 is less than or equal to A3, and the roughness Ra is less than or equal to 0.06 μm. In some other embodiments, the thickness of the substrate 10 may also be greater than or equal to 0.25 mm.

[0078] It should be noted that, in the process of forming the substrate 10 by injection molding, the mold is preferably a three-plate mold with hot-to-cold runners, the mold can be an electroformed insert, the mold surface is subjected to high-gloss polishing, the mirror effect grade of the mold surface is less than or equal to A3, the roughness Ra is less than or equal to 0.06 μm, and the polymer material is injected into the injection mold by a single-point injection method to avoid the presence of weld lines or deformation of the substrate 10, which helps to improve the surface quality of the substrate 10. Among them, the drying conditions of the plastic particles are preferably 140°C / 6H, the temperature of the injection mold (i.e., mold temperature) is between 135°C and 170°C, the temperature of the polymer material (i.e., material temperature) is between 330°C and 400°C, the injection pressure of the polymer material injected into the injection mold is between 700bar and 1500bar, and the injection speed (i.e., shooting speed) is greater than or equal to 20mm / s, so as to improve the surface quality of the substrate 10.

[0079] The polymer material weighing 2.16 kg has a fluidity greater than or equal to 22 g / min at a temperature of 350 degrees Celsius, so that the substrate 10 can be injection molded by a single-point injection method. The fluidity test of the polymer material used in the substrate 10 meets the international standard ISO 1133. In other words, the polymer material used in the substrate 10 has a high melt index and high fluidity, which not only helps to achieve high-precision molding of the substrate 10, but also helps to obtain a high-quality outer surface and reduce other appearance defects such as weld lines on the outer surface of the substrate 10.

[0080] Step S2, forming a metal coating layer 20 on the outer surface 101. The material of the metal coating layer 20 includes at least one of titanium, chromium, tungsten, vanadium, niobium, zirconium, hafnium, titanium carbide and tungsten carbide. Exemplarily, the thickness of the metal coating layer 20 is 0.2μm to 8μm, the pencil hardness test of the metal coating layer 20 is ≥2H, and the adhesion of the metal coating layer 20 is ≥4B. The metal coating layer 20 not only has a high-quality metal effect, but also can obtain different colors by selecting different metal materials, which helps to improve the appearance of the structural part 800. The adhesion of the metal coating layer 20 is measured by a hundred-grid test.

[0081] Specifically, the substrate 10 is placed in a vacuum coating machine for high-temperature sputtering coating to form a metal coating layer 20 on the outer surface 101. Exemplarily, physical vapor deposition (PVD) is used to form the metal coating layer 20. It should be noted that since the polymer materials used in the substrate 10 are all non-crystalline special engineering plastics, the polar groups of the non-crystalline special engineering plastics help the substrate 10 and the metal coating layer 20 to form a strong bonding force, so the physical vapor deposition process can be used directly on the outer surface 101 for coating. Moreover, since the thermal deformation temperature of the polymer material used in the substrate 10 is greater than or equal to 175°C, that is, the polymer material used in the substrate 10 has the characteristic of high temperature resistance, it is helpful for the substrate 10 to be subjected to high-temperature sputtering coating. In addition, since the thermal expansion coefficient of the polymer material used in the substrate 10 is less than or equal to 60*10 -6 / K, that is, the thermal expansion coefficient of the polymer material is low. The lower thermal expansion coefficient of the substrate 10 can not only reduce the difference in thermal expansion coefficient between the substrate 10 and the metal coating layer 20, which helps to improve the structural stability between the substrate 10 and the metal coating layer 20, but also avoid cracking of the metal coating layer 20.

[0082] It should be noted that the high-temperature sputtering coating process is used to form the metal coating layer 20. Not only does the metal coating layer 20 have high purity and good density, but also has strong bonding with the substrate 10, which helps to improve the reliability of the structural component 800. In addition, compared with the conventional vacuum non-conductive coating process used to form the metal coating layer, the high-temperature sputtering coating process is simpler and pollution-free. Furthermore, the non-conductive vacuum coating process is often used for surface decoration of glass-fiber-filled polycarbonate (PC) resin parts. The use of physical vapor deposition technology can save three spraying steps. In particular, parts using non-conductive vacuum coating are prone to oil accumulation and fat edges, which is not conducive to achieving high-quality metallization effects.

[0083] In some other embodiments, physical vapor deposition coating can be directly performed on the outer surface 101 of the substrate 10, or vacuum non-conductive plating, ordinary spraying, water plating and other processes can be used to coat the outer surface 101 of the substrate 10, and the present application does not impose any specific restrictions on this.

[0084] It should be noted that the method for preparing the structural part may further include step S3, post-processing the metal coating layer 20 and the substrate 10. Specifically, the substrate 10 formed with the metal coating layer 20 may be post-processed by computer numerical control (CNC) or sprayed with a transparent topcoat according to actual product requirements.

[0085] The method for preparing the structural part shown in the embodiment of the present application directly forms a metal coating layer 20 on the outer surface 101 of the substrate 10. This method can easily prepare a highly refined structural part 800 with a metal-like appearance effect. The structural part 800 has high gloss, good flatness, excellent reliability, strong product performance, low cost and light weight. The metal coating layer 20 and the substrate 10 are firmly bonded, have excellent wear resistance, and are not easy to crack or fall off. The structural part 800 prepared by this method has both a refined appearance and light weight, and has a strong product performance. Moreover, the structural part 800 prepared by this method has high strength, good toughness, good dimensional stability, and excellent chemical resistance.

[0086] The above description is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application; in the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A camera decorative piece, used in a housing of an electronic device, characterized in that: It comprises a substrate and a metal coating layer, wherein the substrate comprises an outer surface, the outer surface of the substrate is provided with a texture pattern, the texture pattern is a part of the substrate, and the metal coating layer covers the texture pattern; The substrate is made of a polymer material having polar groups, the thermal deformation temperature of the polymer material is greater than or equal to 175°C, and the thermal expansion coefficient of the polymer material is less than or equal to 60*10 -6 / K, tested according to international standard ISO1133, the flow rate of the polymer material at a pressure weight of 2.16kg and a temperature of 350°C is greater than or equal to 22g / 10min.

2. The camera decoration according to claim 1, characterized in that: The mirror effect grade of the outer surface of the substrate is less than or equal to A3, and the outer surface roughness Ra of the substrate is less than or equal to 0.06 μm.

3. The camera decoration according to claim 1, characterized in that: The texture pattern includes a plurality of texture pattern units.

4. The camera decoration according to claim 3, characterized in that: The cross section of each of the texture pattern units is triangular.

5. The camera decoration according to claim 1, characterized in that: The notched impact strength of the substrate is greater than or equal to 4 kJ / m 2 .

6. The camera decoration according to claim 1, characterized in that: The flexural modulus of the substrate is greater than or equal to 2500 MPa.

7. The camera decoration according to claim 1, characterized in that: The adhesion of the metal coating layer is greater than or equal to 4B.

8. The camera decoration according to claim 7, characterized in that: The thickness of the metal coating layer is between 0.2 μm and 8 μm.

9. The camera decoration according to claim 8, characterized in that: The pencil hardness test of the metal coating layer is ≥2H.

10. The camera decoration according to any one of claims 1 to 9, characterized in that: The polar group is an imide group, a sulfone group, a diphenyl sulfone group or a phthalamide group.

11. The camera decoration according to any one of claims 1 to 9, characterized in that: The polymer material includes at least one of polyetherimide, polysulfone plastics, polyethersulfone, polyphenylene sulfone resin and polyphthalamide.

12. The camera decoration according to any one of claims 1 to 9, characterized in that: The material of the metal coating layer includes at least one of titanium, chromium, tungsten, vanadium, niobium, zirconium, hafnium, titanium carbide and tungsten carbide.

13. The camera decoration according to any one of claims 1 to 9, characterized in that: The substrate is prepared by a single-point glue injection method.

14. The camera decoration according to any one of claims 1 to 9, characterized in that: The substrate does not contain weld lines.

15. The camera decoration according to any one of claims 1 to 9, characterized in that: The camera decorative component further comprises a topcoat layer, and the topcoat layer is arranged on the surface of the metal coating layer away from the substrate.

16. The camera decoration according to any one of claims 1 to 9, characterized in that: The camera decoration also includes a color paint layer and a top paint layer. The color paint layer is arranged on the surface of the metal coating layer away from the substrate, and the top paint layer is arranged on the surface of the color paint layer away from the metal coating layer.

17. An electronic device, characterized in that: It comprises a shell and a camera decoration as claimed in any one of claims 1 to 16, wherein the camera decoration is mounted on the shell.

18. A method for preparing a camera decorative part, characterized in that: include: The polymer material having polar groups is injection molded to form a substrate, wherein the thermal deformation temperature of the polymer material is greater than or equal to 175° C., and the thermal expansion coefficient of the polymer material is less than or equal to 60*10 -6 / K, tested according to international standard ISO 1133, the flow rate of the polymer material at a pressure weight of 2.16 kg and a temperature of 350° C. is greater than or equal to 22 g / 10 min, the substrate includes an outer surface, the outer surface of the substrate is provided with a texture pattern, and the texture pattern is a part of the substrate; A metal coating layer is formed on the outer surface, and the metal coating layer covers the texture pattern.

19. The method for preparing a camera decorative piece according to claim 18, characterized in that: In the step of forming a metal coating on the outer surface, the metal coating is formed by a physical vapor deposition process.

20. The method for preparing a camera decorative piece according to claim 19, characterized in that: In the step of injection molding the polymer material having polar groups to form the substrate, the mold temperature of the injection mold is between 135°C and 170°C, the temperature of the polymer material is between 330°C and 400°C, the injection pressure of the polymer material injected into the injection mold is between 700bar and 1500bar, and the injection speed is greater than or equal to 20mm / s.

21. The method for preparing a camera decorative piece according to any one of claims 18 to 20, characterized in that: The polymer material is injected into the injection mold by a single-point injection method.

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