Plastic mobile phone frame manufacturing method and plastic mobile phone frame

Abstract

The application discloses a plastic mobile phone frame manufacturing method and a plastic mobile phone frame and relates to the technical field of mobile phone accessory processing. The plastic mobile phone frame manufacturing method comprises the following steps: manufacturing an aluminum powder layer on one side of a base film; pasting the base film on the inner wall of a mold and making the aluminum powder layer face the inner cavity of the mold; pouring plastic into the mold to form a frame body and a connecting piece, so that an intermediate product is obtained, the intermediate product is formed with an aluminum-plastic interlaced layer on the side facing the base film; tearing off the base film and polishing the surface of the intermediate product; plating an aluminum nitride-zirconium nitride composite layer on the aluminum-plastic interlaced layer; and plating a titanium nitride-zirconium nitride composite layer on the side of the aluminum nitride-zirconium nitride composite layer away from the aluminum-plastic interlaced layer. The plastic mobile phone frame manufactured by the plastic mobile phone frame manufacturing method can improve the bonding force between the reinforcing film and the frame body and improve the shielding effect.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of mobile phone accessory processing, and particularly relates to a plastic mobile phone frame manufacturing method and a plastic mobile phone frame. BACKGROUND

[0002] Electronic products such as mobile phones usually require good screen effect, wear-resistant appearance and light weight.

[0003] However, the parts of the existing electronic products, such as mobile phone frames, are mostly made of aluminum by pressure casting, and then a strengthening layer is formed on the aluminum to improve the wear resistance. The aluminum is a conductor material, which makes the shielding performance of the mobile phone frame insufficient, and the bonding force between the strengthening layer and the mobile phone frame is insufficient. SUMMARY

[0004] The application provides a plastic mobile phone frame manufacturing method and a plastic mobile phone frame, which improve the bonding force between the strengthening film and the frame body and improve the shielding effect.

[0005] The application provides a plastic mobile phone frame manufacturing method, which comprises the following steps.

[0006] An aluminum powder layer is formed on one side of a base film;

[0007] The base film is pasted to the inner wall of a mold, and the aluminum powder layer faces the inner cavity of the mold; plastic is poured into the mold to form a frame body and a connecting piece, so that an intermediate product is obtained, and an aluminum-plastic interlaced layer is formed on the side of the intermediate product facing the base film;

[0008] The base film is torn off, and the surface of the intermediate product is polished;

[0009] An aluminum nitride-zirconium nitride composite layer is plated on the aluminum-plastic interlaced layer;

[0010] A titanium nitride-zirconium nitride composite layer is plated on the side of the aluminum nitride-zirconium nitride composite layer away from the aluminum-plastic interlaced layer.

[0011] In some possible implementation manners, the aluminum powder layer formed on one side of the base film comprises the following steps.

[0012] Aluminum powder with a diameter of 0.1 mm to 0.2 mm is sprayed on the base film with a thickness of 0.3 mm to form the aluminum powder layer on the base film.

[0013] In some possible implementation manners, the thickness of the aluminum powder layer is 0.3 mm to 0.4 mm.

[0014] In some possible implementation manners, the aluminum nitride-zirconium nitride composite layer plated on the aluminum-plastic interlaced layer comprises the following steps.

[0015] The positive pole of the power supply is connected to the workpiece holder in which the intermediate product is placed, the negative pole of the power supply is connected to the target material, the target material comprises aluminum nitride, zirconium nitride and aluminum, the voltage of the power supply is set to 800V-1000V, the temperature in the vacuum furnace is controlled to 70℃-80℃, and the vacuum degree in the vacuum furnace is controlled to 0.1Pa-1Pa.

[0016] The power supply is started, and the aluminum nitride-zirconium nitride composite layer is prepared on the aluminum-plastic interlaced layer by evaporation for 20-30 minutes.

[0017] In some possible embodiments, the thickness of the aluminum nitride-zirconium nitride composite layer is 2-3μm.

[0018] In some possible embodiments, the target material comprises aluminum nitride with a mass ratio of 47%-53%, zirconium nitride with a mass ratio of 27%-33%, and aluminum with a mass ratio of 17%-23%.

[0019] In some possible embodiments, the titanium nitride-zirconium nitride composite layer is plated on the side of the aluminum nitride-zirconium nitride composite layer away from the aluminum-plastic interlaced layer, and the method comprises the following steps.

[0020] The positive pole of the power supply is connected to the workpiece holder in which the intermediate product is placed, the negative pole of the power supply is connected to the target material, the target material comprises aluminum nitride, zirconium nitride and aluminum, the voltage of the power supply is set to 800V-1000V, the temperature in the vacuum furnace is controlled to 70℃-80℃, and the vacuum degree in the vacuum furnace is controlled to 0.1Pa-1Pa.

[0021] The power supply is started, and the aluminum nitride-zirconium nitride composite layer is prepared on the aluminum-plastic interlaced layer by evaporation for 20-30 minutes.

[0022] In some possible embodiments, the thickness of the aluminum nitride-zirconium nitride composite layer is 2-3μm.

[0023] In some possible embodiments, the target material comprises aluminum nitride with a mass ratio of 47%-53%, zirconium nitride with a mass ratio of 27%-33%, and aluminum with a mass ratio of 17%-23%.

[0024] In addition, the application further provides a plastic mobile phone frame, which is prepared by the plastic mobile phone frame manufacturing method provided in the above embodiments, and comprises a frame body and a connecting piece. The frame body is arranged around the circumferential side of the connecting piece and is in an integrated structure with the connecting piece. The side of the frame body away from the connecting piece is sequentially provided with an aluminum-plastic interlaced layer, an aluminum nitride-zirconium nitride composite layer and a titanium nitride-zirconium nitride composite layer.

[0025] The application has the beneficial effects that: the plastic mobile phone frame prepared by the plastic mobile phone frame manufacturing method provided by the application can replace aluminum-based materials with plastics, so that the plastic mobile phone frame has lighter weight and shielding effect. In addition, the frame body and the connecting piece are integrally formed, which can play a good sealing effect in use. In addition, the frame body is provided with a high-hardness reinforcing film on the side away from the connecting piece, which can improve the wear resistance of the plastic mobile phone frame. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the application, the drawings needed to be used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0027] Figure 1 A flowchart of the plastic mobile phone frame manufacturing method in some embodiments is shown;

[0028] Figure 2 A flowchart of step S100 in some embodiments is shown;

[0029] Figure 3 A flowchart of step S200 in some embodiments is shown;

[0030] Figure 4 A partial structure diagram of the plastic mobile phone frame in some embodiments is shown;

[0031] Figure 5 A structure diagram of the plastic mobile phone frame in some embodiments is shown.

[0032] Main element symbol explanation:

[0033] 110-frame body; 120-connecting piece; 200-reinforcing film; 210-aluminum-plastic staggered layer; 220-aluminum nitride-zirconium nitride composite layer; 230-titanium nitride-zirconium nitride composite layer. DETAILED DESCRIPTION

[0034] The embodiments of the application will be described in detail below, and examples of the embodiments are shown in the drawings, wherein the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the application, and cannot be understood as a limitation on the application.

[0035] In the description of the present application, it needs to be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the purpose of facilitating the description of the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation to the present application.

[0036] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited.

[0037] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral; it can be mechanical connection, or electrical connection; it can be direct connection, or indirect connection through intermediate medium, or internal communication of two elements or interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0038] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can be direct contact between the first and second features, or indirect contact between the first and second features through intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature can be directly above or obliquely above the first feature, or only indicate that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature can be directly below or obliquely below the first feature, or only indicate that the horizontal height of the first feature is less than that of the second feature.

[0039] As shown in Figure 1 , Figure 4 and Figure 5 , a plastic mobile phone frame manufacturing method is provided in the embodiment, which can be used for manufacturing a plastic mobile phone frame.

[0040] In some embodiments, the plastic mobile phone frame manufacturing method can include:

[0041] S100, spray aluminum powder on one side of the base film to form an aluminum powder layer.

[0042] In some embodiments, the base film can be an adhesive tape with an adhesive layer on one side. In embodiments, the aluminum powder can be sprayed on the side of the base film away from the adhesive layer in an environment below 100℃, and the diameter of the aluminum powder can be 0.1mm-0.2mm, so that an aluminum powder layer can be formed on one side of the base film. In this case, the thickness of the aluminum powder layer can be set to 0.3mm-0.4mm.

[0043] In embodiments, spraying the aluminum powder in an environment below 100℃ can reduce the oxidation of the aluminum powder and avoid deformation of the base film due to heat, ensuring the flatness of the base film.

[0044] S200, paste the base film to the inner wall of the mold, and make the aluminum powder layer face the inner cavity of the mold, pour plastic into the mold to form the frame body 110 and the connecting piece 120, and obtain an intermediate product, and the aluminum-plastic interlaced layer 210 is formed on the side of the intermediate product facing the base film.

[0045] In some embodiments, the adhesive layer of the base film can be pasted to the inner wall of the mold, and the side of the base film with the aluminum powder layer can face the inner cavity of the mold. In this case, the diameter of the aluminum powder in the aluminum powder layer is 0.1mm-0.2mm, and there is a gap between adjacent aluminum powders. Thus, during the pouring of plastic, part of the plastic will fill the gap between adjacent aluminum powders, and an aluminum-plastic interlaced layer 210 with a thickness of 0.3mm-0.4mm will be formed. Accordingly, the aluminum powder can penetrate to the edge position of the side of the frame body 110 away from the connecting piece 120. In addition, the frame body 110 and the connecting piece 120 can be integrally formed, i.e. to obtain an intermediate product, which improves the sealing performance of the plastic mobile phone frame in use. After pouring is completed, the intermediate product can be solidified and demolded, so that the solidified intermediate product is taken out of the mold. It can be understood that when the intermediate product is taken out of the mold, the adhesive tape can be taken out together with the intermediate product and attached to the side of the intermediate product provided with the aluminum-plastic interlaced layer 210.

[0046] S300, tear off the base film and polish the surface of the intermediate product.

[0047] In embodiments, the adhesive tape on the intermediate product can be torn off, and the surface of the intermediate product can be polished by a polishing machine. In this case, the side of the intermediate product provided with the aluminum-plastic interlaced layer 210 can be polished to remove dirt and aluminum oxide on the surface of the aluminum-plastic interlaced layer 210, and the surface roughness of the intermediate product can meet the processing requirements of the plastic mobile phone frame.

[0048] S400, plating an aluminum nitride-zirconium nitride composite layer 220 on the aluminum-plastic interlaced layer 210.

[0049] In some embodiments, step S400 can be completed in a coating device. The coating device can include a vacuum furnace and a power supply, and a workpiece holder for placing the intermediate product can be arranged in the vacuum furnace.

[0050] Further combined Figure 2 In some embodiments, step S400 can include:

[0051] S410, connecting the positive pole of the power supply to the workpiece holder for placing the intermediate product, connecting the negative pole of the power supply to the target material, the target material including aluminum nitride, zirconium nitride and aluminum, setting the voltage of the power supply to 800V-1000V, and controlling the temperature in the vacuum furnace to 70℃-80℃ and the vacuum degree in the vacuum furnace to 0.1Pa-1Pa.

[0052] In some embodiments, the mass ratio of the components in the target material can be set to 47%-53% of aluminum nitride, 27%-33% of zirconium nitride, and 17%-23% of aluminum. For example, in some embodiments, the mass ratio of the components in the target material can be set to 47% of aluminum nitride, 31% of zirconium nitride, and 22% of aluminum. Alternatively, the mass ratio of the components in the target material can be set to 50% of aluminum nitride, 30% of zirconium nitride, and 20% of aluminum.

[0053] S420, starting the power supply, and evaporating for 20-30 minutes to form an aluminum nitride-zirconium nitride composite layer 220 on the aluminum-plastic interlaced layer 210.

[0054] Since aluminum nitride and zirconium nitride are not conductive, in the embodiments of the present application, the addition of aluminum in the target material can make the target material conductive. Thus, under the action of high voltage, the target material (cathode) will cause aluminum ion sputtering due to the glow effect, and aluminum nitride and zirconium nitride can be evaporated and deposited on the intermediate product. Specifically, aluminum nitride and zirconium nitride can be deposited on the surface of the aluminum-plastic interlaced layer 210 and form an aluminum nitride-zirconium nitride composite layer 220 on the surface of the aluminum-plastic interlaced layer 210. During the coating process, since the aluminum ion is positively charged and has the same electrical properties as the workpiece holder, the aluminum ion will repel the workpiece holder and will not be deposited on the intermediate product.

[0055] In some embodiments, a 2-3μm thick aluminum nitride-zirconium nitride composite layer 220 can be coated on the surface of the aluminum-plastic interlaced layer 210.

[0056] S500, coating a titanium nitride-zirconium nitride composite layer 230 on the side of the aluminum nitride-zirconium nitride composite layer 220 away from the aluminum-plastic interlaced layer 210.

[0057] In the embodiments, step S500 can also be completed in a coating device.

[0058] Further combined Figure 3 In some embodiments, step S500 can include:

[0059] S510, connect the positive pole of the power supply to the workpiece frame in which the intermediate product is placed, connect the negative pole of the power supply to the target material, the target material comprising titanium nitride, zirconium nitride and titanium, set the voltage of the power supply to 800V-1000V, control the temperature in the vacuum furnace to 70℃-80℃, and control the vacuum degree in the vacuum furnace to 0.1Pa-1Pa.

[0060] In some embodiments, the mass ratio of each component in the target material can be set as follows: titanium nitride accounts for 67%-73%, zirconium nitride accounts for 17%-23%, and titanium accounts for 7%-13%. For example, in some embodiments, the mass ratio of each component in the target material can be set as follows: titanium nitride accounts for 73%, zirconium nitride accounts for 18%, and titanium accounts for 9%. Alternatively, the mass ratio of each component in the target material can be set as follows: titanium nitride accounts for 70%, zirconium nitride accounts for 20%, and titanium accounts for 10%.

[0061] In the embodiments, the vacuum degree, temperature, power supply connection mode and parameter setting of the power supply in the process of plating the aluminum nitride-zirconium nitride composite layer 220 can be consistent with those in the process of plating the aluminum nitride-zirconium nitride composite layer 220.

[0062] S520, start the power supply and evaporate for 50-60 minutes to obtain a titanium nitride-zirconium nitride composite layer 230 on the side of the aluminum nitride-zirconium nitride composite layer 220 away from the aluminum-plastic interlaced layer 210.

[0063] Under the action of high voltage, titanium nitride and zirconium nitride can be evaporated and deposited on the aluminum nitride-zirconium nitride composite layer 220 to form the aluminum nitride-zirconium nitride composite layer 220. Since the conductivity of titanium nitride is relatively weak, in the embodiments of the present application, titanium is added to the target material to improve the conductivity of the target material, thereby improving the evaporation rate of the aluminum nitride-zirconium nitride composite layer 220. In some embodiments, the thickness of the aluminum nitride-zirconium nitride composite layer 220 can be set to 5-6μm.

[0064] Correspondingly, the aluminum-plastic interlaced layer 210, the aluminum nitride-zirconium nitride composite layer 220 and the titanium nitride-zirconium nitride composite layer 230 can be used as the reinforcing film 200 on one side of the frame body 110, and can have good wear resistance.

[0065] The plastic mobile phone frame made by the method provided in the present application can have the following advantages:

[0066] (1) By using plastic to replace the traditional aluminum-based mobile phone frame, the weight of the mobile phone frame can be further reduced, which is conducive to the lightweight design of electronic products.

[0067] (2) The frame body 110 and the connecting piece 120 are integrally injection molded by plastic, so that the sealing performance can be higher in use.

[0068] (3) The frame body 110 is insulated by itself, and the conductive performance of the reinforcing film 200 is extremely weak, so that the plastic mobile phone frame has good shielding performance, and the shielding effect is much better than that of the electroplating layer in the traditional technology (because the electroplating layer is conductive, the shielding performance is poor).

[0069] (4) In the aluminum-plastic interlaced layer 210 of the reinforcing film 200, the aluminum powder is interlaced with the plastic, and the aluminum powder can penetrate into the internal structure of the frame body 110, so that the aluminum-plastic interlaced layer 210 and the frame body 110 have good bonding performance. In addition, in the aluminum nitride-zirconium nitride composite layer 220, the aluminum nitride has affinity with the aluminum powder, so that the aluminum nitride-zirconium nitride composite layer 220 and the aluminum-plastic interlaced layer 210 have good bonding force. In addition, the titanium nitride-zirconium nitride composite layer 230 and the aluminum nitride-zirconium nitride composite layer 220 contain the same component zirconium nitride, so that the titanium nitride-zirconium nitride composite layer 230 and the aluminum nitride-zirconium nitride composite layer 220 have good bonding ability. Thus, the reinforcing film 200 in the plastic mobile phone frame of the present application has good bonding ability with the frame body 110, and the risk of delamination of the reinforcing film 200 is reduced.

[0070] (5) The hardness of the titanium nitride-zirconium nitride composite layer 230 on the outermost layer of the reinforcing film 200 is Hv1300 or more, which has very high wear resistance, so that the reinforcing film 200 as a whole has high wear resistance. In addition, the hardness of the aluminum nitride-zirconium nitride composite layer 220 is Hv800 or more. From the inner layer to the outer layer of the plastic mobile phone frame, the hardness of the plastic, the aluminum-plastic interlaced layer 210, the aluminum nitride-zirconium nitride composite layer 220, and the titanium nitride-zirconium nitride composite layer 230 increases in turn, forming a hardness gradient, and the inner layer can support the hardness of the outer layer, so that the reinforcing layer is very wear-resistant.

[0071] As shown in Figure 4 and Figure 5 The plastic mobile phone frame provided in the embodiment can be made by the plastic mobile phone frame manufacturing method provided in the embodiment. The plastic mobile phone frame can include a frame body 110 and a connecting piece 120. The frame body 110 can be arranged around the connecting piece 120, and the frame body 110 and the connecting piece 120 can be integrally injection molded. In addition, the side of the frame body 110 away from the connecting piece 120 can be provided with a reinforcing film 200, and the reinforcing film 200 can include an aluminum-plastic interlaced layer 210, an aluminum nitride-zirconium nitride composite layer 220, and a titanium nitride-zirconium nitride composite layer 230 arranged in turn. The aluminum-plastic interlaced layer 210 can be an integral structure with the frame body 110, that is, the aluminum-plastic interlaced layer 210 can be fused to the side edge position of the frame body 110 away from the connecting piece 120.

[0072] In the description of the specification, the description using the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" etc. means that the particular feature, structure, material or characteristic being described is included in at least one embodiment or example of the present application. The illustrative appearances of the above-mentioned terms in various places in the specification are not necessarily referred to the same embodiment or example. Moreover, the particular features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples. Furthermore, the terms "comprise", "comprising", "include", "including", "contain", "containing" or variations thereof are used inclusively and do not exclude the additional inclusion of unrecited features, structures, materials, or characteristics.

[0073] Although the embodiments of the present application have been shown and described above, it is understood that the above-described embodiments are exemplary and are not to be interpreted as limiting the present application, and ordinary skilled people in the art can make changes, modifications, replacements and variations to the above-described embodiments within the scope of the present application.

Claims

1. A method for manufacturing a plastic mobile phone frame, characterized in that, The application relates to a plastic mobile phone frame manufacturing method. An aluminum powder layer is formed on one side of a base film; The base film is pasted to the inner wall of a mold, and the aluminum powder layer faces the inner cavity of the mold; plastic is poured into the mold to form a frame body and a connecting piece, so that an intermediate product is obtained, and an aluminum-plastic interlaced layer is formed on the side of the intermediate product facing the base film; The base film is torn off, and the surface of the intermediate product is polished; An aluminum nitride-zirconium nitride composite layer is plated on the aluminum-plastic interlaced layer; A titanium nitride-zirconium nitride composite layer is plated on the side of the aluminum nitride-zirconium nitride composite layer away from the aluminum-plastic interlaced layer.

2. The method of claim 1, wherein the plastic mobile phone frame is made of a material selected from the group consisting of ABS, PC, and PMMA. The aluminum powder layer is formed on one side of the base film by spraying aluminum powder with a diameter of 0.1mm to 0.2mm on the base film with a thickness of 0.3mm. The thickness of the aluminum powder layer is 0.3mm to 0.4mm.

3. The method of claim 1, wherein the plastic mobile phone frame is made of a material selected from the group consisting of ABS, PC, and PMMA. The aluminum nitride-zirconium nitride composite layer is plated on the aluminum-plastic interlaced layer by connecting the positive pole of a power supply to a workpiece holder in which the intermediate product is placed, connecting the negative pole of the power supply to a target material, setting the voltage of the power supply to 800V-1000V, controlling the temperature in a vacuum furnace to 70 DEG C-80 DEG C, and controlling the vacuum degree in the vacuum furnace to 0.1Pa-1Pa; and evaporating for 20min to 30min to form the aluminum nitride-zirconium nitride composite layer on the aluminum-plastic interlaced layer.

4. The method of claim 1, wherein the plastic mobile phone frame is made of a material selected from the group consisting of ABS, PC, and PMMA. The thickness of the aluminum nitride-zirconium nitride composite layer is 2um to 3um. The target material comprises aluminum nitride with a mass ratio of 47% to 53%, zirconium nitride with a mass ratio of 27% to 33%, and aluminum with a mass ratio of 17% to 23%. The titanium nitride-zirconium nitride composite layer is plated on the side of the aluminum nitride-zirconium nitride composite layer away from the aluminum-plastic interlaced layer by connecting the positive pole of a power supply to a workpiece holder in which the intermediate product is placed, connecting the negative pole of the power supply to a target material, setting the voltage of the power supply to 800V-1000V, controlling the temperature in a vacuum furnace to 70 DEG C-80 DEG C, and controlling the vacuum degree in the vacuum furnace to 0.1Pa-1Pa; and evaporating for 50min to 60min to form the titanium nitride-zirconium nitride composite layer on the side of the aluminum nitride-zirconium nitride composite layer away from the aluminum-plastic interlaced layer.

5. The method of claim 4, wherein the plastic cell phone frame is made of a material selected from the group consisting of ABS, PC, and PMMA. The thickness of the titanium nitride-zirconium nitride composite layer is 5um to 6um.

6. The method of claim 4, wherein the plastic mobile phone frame is made of a material selected from the group consisting of ABS, PC, and PMMA. The target material comprises titanium nitride with a mass ratio of 67% to 73%, zirconium nitride with a mass ratio of 17% to 23%, and titanium with a mass ratio of 7% to 13%.

7. The method of claim 1 to 6, wherein, The plastic mobile phone frame manufactured by the method comprises a frame body and a connecting piece, the frame body is arranged around the periphery of the connecting piece and is in an integrated structure with the connecting piece, and the side of the frame body away from the connecting piece is sequentially provided with an aluminum-plastic interlaced layer, an aluminum nitride-zirconium nitride composite layer and a titanium nitride-zirconium nitride composite layer. ​ ​ 8. The method of claim 7, wherein the plastic cell phone frame is made of a material selected from the group consisting of ABS, PC, and PMMA. ​ 9. The method of claim 7, wherein the plastic mobile phone frame is made of a material selected from the group consisting of ABS, PC, and PMMA. ​ 10. A plastic cell phone bezel, characterized by, ​

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