Surface treatment method for irregularly shaped mobile phone back plate

Abstract

The present application relates to a kind of special-shaped structure mobile phone back plate surface treatment method, belong to ceramic processing technical field.The special-shaped structure mobile phone back plate surface treatment method includes the following steps: polishing treatment, cutting processing, grinding processing and polishing treatment.The present application is polished to mobile phone back plate, and the outer surface of mobile phone back plate is cut using CNC machine tool, the present application increases grinding processing procedure between CNC cutting processing procedure and polishing procedure, and the outer surface of mobile phone back plate is ground using double-sided grinder, can eliminate the stress generated after CNC processing of mobile phone back plate to a certain extent, can effectively improve the strength of mobile phone back plate, improve the yield of mobile phone back plate, also can reduce the time required in subsequent polishing procedure;After a short time of polishing treatment, mobile phone back plate product has good surface light and shadow effect.

Description

Technical Field

[0001] This invention relates to the field of ceramic processing technology, and in particular to a method for surface treatment of irregularly shaped mobile phone back panels. Background Technology

[0002] With the development of science and technology and modern society, people have higher and higher requirements for electronic products, especially for the back panel and appearance of mobile phones used in daily life. Zirconia ceramics, due to their high wear resistance and high hardness, are widely used in mobile phone back panels and other fields.

[0003] Because phone back panels with crater-shaped cameras differ from those with conventional flat cameras, they are considered irregularly shaped and are currently quite popular. Compared to back panels with conventional flat cameras, irregularly shaped back panels present greater challenges in surface treatment. Current surface treatment technologies typically involve rough grinding of the outer surface followed by CNC machining. CNC machining requires a large-diameter grinding head (around 100mm), which carries a high risk of tool burn-in, short tool life, high processing costs, and low mass production feasibility. Furthermore, defects such as tool marks and dents created during CNC machining are difficult to remove, resulting in poor surface finish and low yield rates. The risk of tool burn-in during processing also contributes to high costs and low customer satisfaction.

[0004] Therefore, there is an urgent need to improve the processing procedures to obtain irregularly shaped mobile phone back panels with excellent surface quality. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a surface treatment method for irregularly shaped mobile phone back panels. This invention adds a grinding process between the CNC cutting process and the polishing process. A double-sided grinding machine is used to grind the outer surface of the mobile phone back panel, which can eliminate the stress generated after CNC machining to a certain extent, effectively improve the strength of the mobile phone back panel, and increase the yield of the mobile phone back panel. After polishing, the finished mobile phone back panel has a better surface gloss effect.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A surface treatment method for an irregularly shaped mobile phone back panel includes the following steps:

[0008] S1. Prepare a mobile phone back panel, which includes a frame and a back panel body, and the back panel body is provided with a volcano-shaped opening.

[0009] S2. Polish the outer surface of the phone back panel;

[0010] S3. Use a CNC machine tool to cut and process the outer surface of the phone back panel;

[0011] S4. Use a double-sided grinding machine to grind the outer surface of the phone back panel;

[0012] S5. Polish the back panel of the phone to obtain the finished phone back panel.

[0013] This invention involves polishing the phone back panel and then using a CNC machine tool to cut the outer surface of the phone back panel. By adding a grinding process between the CNC cutting and polishing processes, and using a double-sided grinding machine to grind the outer surface of the phone back panel, this invention can, to some extent, eliminate the stress generated after CNC machining, effectively improve the strength of the phone back panel, increase the yield rate, and reduce the time required for subsequent polishing processes. After a shorter polishing time, the finished phone back panel has a better surface gloss effect.

[0014] In a preferred embodiment of the present invention, the mobile phone back panel is a ceramic mobile phone back panel.

[0015] In a preferred embodiment of the present invention, step S2 includes:

[0016] S21. Use a grinding wheel to polish the outer surface of the frame of the mobile phone back panel to remove the burrs on the outer surface of the frame.

[0017] S22. Use a grinding wheel to polish the outer surface of the back panel of the mobile phone.

[0018] In a preferred embodiment of the present invention, the cutting tool of the CNC machine tool is a diamond grinding head with a diameter of 8 to 40 mm and a mesh size of 80 to 130. The distance between any two adjacent grinding heads is 0.01 to 0.06 mm.

[0019] In a preferred embodiment of the present invention, step S3 controls the CNC machine tool's cutting speed to 10000-15000 r / min, the machining removal amount to 0.15-0.2 mm, and the machining dimensional accuracy to ±0.05 mm.

[0020] Research has shown that because this invention uses a double-sided grinding machine to grind the phone back panel in step S4, the dimensional accuracy requirements for the cutting process in step S3 are reduced, only needing to be controlled at ±0.05mm. The cutting process uses a smaller diameter grinding head, resulting in a longer lifespan and lower cost. Furthermore, the CNC machine tool cutting process significantly reduces defects on the top and bottom surfaces, improving the yield of the phone back panel. These defects include grinding wheel lines, scratches, overcutting, and cracks generated on the phone back panel surface in previous processes.

[0021] In a preferred embodiment of the present invention, in step S4, the rotation speed of the double-sided grinding machine is 25-35 r / min, the amount of material removed is 0.02-0.05 mm, and the grinding pressure is 10-15 kg / piece.

[0022] The grinding pressure refers to the pressure applied to the back panel of a single mobile phone during grinding.

[0023] In a preferred embodiment of the present invention, the planetary transmission mechanism of the double-sided grinding machine includes a lower grinding disc, a planetary disc, and a sun gear. Both the upper and lower grinding discs of the double-sided grinding machine are provided with grinding pads. The grinding pads are provided with annular clearance grooves. The lower grinding disc is coaxially arranged with the sun gear. A gear ring is provided on the outer periphery of the lower grinding disc. The planetary disc meshes with the gear ring and with the sun gear. The planetary disc is provided with a slot adapted to the clamp, and the center point axis of the planetary disc passes through the slot. Before step S4, the following steps are also included: using a clamp to fix two mobile phone back panels to the slot of the planetary disc. The two mobile phone back panels face each other and are staggered. The crater of the mobile phone back panel corresponds to the annular clearance groove of the grinding pad. During the grinding process, the crater of the mobile phone back panel is accommodated in the corresponding annular clearance groove.

[0024] Furthermore, the central axis of the crater on the back of the two mobile phones coincides with the central axis of the planetary disk, and the central axis of the planetary disk intersects with the central circle of the two annular vent grooves.

[0025] Furthermore, the upper and lower surfaces of the fixture are respectively provided with mounting grooves, the two mounting grooves face each other and are staggered, and the mounting grooves are provided with grooves that fit the frame of the mobile phone back panel.

[0026] Furthermore, the back panel body of the mobile phone back panel protrudes from the slot and mounting slot so that the double-sided grinding machine can grind the outer surface of the back panel body.

[0027] Traditional double-sided grinding machines cut grooves at equal intervals on a planetary disk. The phone back panel is fixed in the empty grooves of the planetary disk by a clamp, so that the phone back panel is distributed around the center of the planetary disk. When grinding the phone back panel using a traditional double-sided grinding machine, the planetary disk rotates, and the phone back panel rotates with the planetary disk, but the phone back panel cannot rotate on its own. In addition, traditional double-sided grinding machines can only be used to process the back panels of phones with conventional flat cameras, and cannot be used to process the back panels of phones with crater-like structures.

[0028] Compared with traditional double-sided grinding machines, this invention sets grinding pads with annular clearance grooves on two grinding discs, and opens a groove at a specific position on the planetary disk. The two mobile phone back panels are fixed to the planetary disk facing each other and staggered by a clamp. When grinding the mobile phone back panel using the double-sided grinding machine of this invention, the two grinding discs revolve around the planetary disk and the two mobile phone back panels rotate coaxially. During the rotation of the mobile phone back panel, the crater is always suspended in the annular clearance groove of the corresponding grinding pad and will not be damaged by grinding.

[0029] Furthermore, the clamp is an elastic clamp, and the hardness of the clamp is 35-50HD.

[0030] Furthermore, when the fixture is in its natural state, the width of the mounting groove of the fixture is W, and the length of the mounting groove is L; the width of the mobile phone back panel is w; the length of the cutting area on the outer surface of the mobile phone back panel in step S3 is l, and W, L, w and l satisfy the following conditions: -5mm≤Ww≤5mm, -5mm≤Ll≤5mm.

[0031] Research has shown that when the hardness and size of the fixture meet the above conditions, it can effectively ensure a smooth transition between the crater on the finished mobile phone back panel and the surrounding ground area, without forming obvious steps (i.e., no stepping phenomenon).

[0032] Furthermore, the width B of the annular vent groove and the maximum width D of the crater satisfy the following condition: 0mm≤BD≤2mm.

[0033] Research has shown that if BD < 0mm, the phone back panel will get stuck during the grinding process, causing a jamming phenomenon and interrupting the grinding process. If BD > 2mm, the area of ​​the phone back panel suspended in the air will be too large, and the grinding cannot reach the outer edge of the crater, resulting in an uneven surface. If BD is greater than the width of the phone back panel, the material may even fall into the annular relief groove.

[0034] In a preferred embodiment of the present invention, step S5 specifically includes:

[0035] S51. A multi-axis machine tool is used to polish the outer surface of the mobile phone back panel after grinding in step S4.

[0036] S52. Polish the outer surface of the mobile phone back panel after step S51 using a brush and a first polishing liquid.

[0037] S53. Use a brush and a second polishing liquid to perform a polishing treatment on the outer surface of the mobile phone back panel after step S52.

[0038] Furthermore, the first polishing liquid and the second polishing liquid may be the same or different polishing liquids.

[0039] Furthermore, the first polishing fluid is a diamond polishing fluid, and the second polishing fluid is a silica sol.

[0040] Furthermore, in step S51, when performing the polishing process, a diamond polishing slurry is used. The abrasive particle size in the diamond polishing slurry is 35-40 μm, and the pressure is controlled at 14-16 MPa. This can control the surface roughness of the outer surface of the phone back panel to within 0.3 μm, which can further remove the grinding wheel marks on the crater-shaped area of ​​the phone back panel.

[0041] Furthermore, in step S52, when performing the polishing process, a diamond polishing slurry is used. The abrasive particle size in the diamond polishing slurry is 8-12 μm, and the pressure is controlled at 14-16 MPa, which can control the surface roughness of the outer surface of the mobile phone back panel to within 0.06 μm.

[0042] Furthermore, in step S53, when performing the light-scanning process, a silica sol solution is used. The particle size of the silica sol in the silica sol solution is 100-810 nm, and the pressure is controlled at 14-16 MPa, which can make the surface of the outer surface of the mobile phone back panel achieve a mirror effect.

[0043] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0044] This invention involves polishing the phone back panel and then using a CNC machine tool to cut the outer surface of the phone back panel. By adding a grinding process between the CNC cutting and polishing processes, and using a double-sided grinding machine to grind the outer surface of the phone back panel, this invention can, to some extent, eliminate the stress generated after CNC machining, effectively improve the strength of the phone back panel, increase the yield rate, and reduce the time required for subsequent polishing processes. After a shorter polishing time, the finished phone back panel has a better surface gloss effect. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of the planetary transmission mechanism provided by the present invention;

[0046] Figure 2 This is a schematic diagram of the structure of the clamp provided by the present invention;

[0047] Figure 3 This is a schematic diagram of the planetary transmission mechanism of a traditional double-sided grinding machine.

[0048] In the diagram, 1-planetary disk, 2-sun gear, 3-lower grinding disk, 4-grinding pad, 41-annular clearance groove, 5-clamp, 51-mounting groove, 52-groove. Detailed Implementation

[0049] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0050] The mobile phone back panel in the following embodiments and comparative examples has a back panel body and a frame disposed on the outer periphery of the back panel body, and a volcano-shaped opening is provided on the back panel body.

[0051] The double-sided grinding machine used in the following embodiments includes a frame, a drive mechanism, an upper grinding disc, a planetary transmission mechanism, and a fixture 5; the upper grinding disc is movably mounted on the frame via a guide mechanism; the structure of the planetary transmission mechanism is as follows: Figures 1-2 As shown, the planetary transmission mechanism includes a planetary disk 1, a sun gear 2, and a lower grinding disk 3. The lower grinding disk 3 is rotatably connected to the shaft of the drive mechanism, and a gear ring is provided on the outer periphery of the lower grinding disk 3. Figure 1 (Not shown in the image), the upper surface of the lower grinding disc 3 and the lower surface of the upper grinding disc are both provided with grinding pads 4, and the grinding pads 4 are provided with annular clearance grooves 41; the sun gear 2 is located above the grinding pads 4 of the lower grinding disc 3, and the sun gear 2 is rotatably connected to the shaft of the drive mechanism; the planetary disk 1 meshes with the gear ring, and the planetary disk 1 meshes with the sun gear 2, and the central axis of all planetary disks 1 intersects with the center line circle of the two annular clearance grooves 41; the planetary disk 1 is provided with a slot adapted to the clamp 5, the central axis of the planetary disk 1 passes through the slot, and the slot penetrates the upper and lower surfaces of the planetary disk 1; the upper and lower surfaces of the clamp 5 are respectively provided with mounting grooves 51, the two mounting grooves 51 face each other and are staggered, and the mounting grooves 51 are provided with grooves 52 adapted to the frame of the mobile phone back panel.

[0052] In use, two phone back panels are respectively installed into the two mounting slots 51 of the clamp 5, so that the edges of the phone back panels are inserted into the corresponding grooves 52. The two phone back panels face each other and are staggered. The main body of the phone back panel protrudes from the corresponding mounting slot 51 and the empty slot of the planetary disk 1, with a protrusion height of 1mm, which facilitates the double-sided grinder to grind the surface of the phone back panel. Then, the clamp 5 with the phone back panels is installed into the empty slot of the planetary disk 1. The central axis of the crater in the two phone back panels coincides with the central axis of the planetary disk 1. The crater of the phone back panel corresponds to the annular clearance groove 41 of the grinding pad 4. After the double-sided grinder is started, the upper grinding disk presses down, the lower grinding disk 3 revolves, and the planetary disk 1 and the two phone back panels rotate coaxially. During the rotation, the crater of the phone back panel is contained in the annular clearance groove 41 of the corresponding side grinding pad 4 and is in a suspended state, which can effectively prevent the crater surface from being ground.

[0053] like Figure 3 As shown, a traditional double-sided grinding machine cuts grooves at equal intervals on a planetary disk. The phone back panel is fixed in the empty grooves of the planetary disk by a clamp, so that the phone back panel is distributed around the center of the planetary disk. When the phone back panel is ground using a traditional double-sided grinding machine, the planetary disk rotates, and the phone back panel rotates with the planetary disk, but the phone back panel cannot rotate on its own. In addition, traditional double-sided grinding machines can only be used to process the back panels of phones with conventional flat cameras, and cannot be used to process the back panels of phones with crater-like structures.

[0054] Compared with traditional double-sided grinding machines, this invention sets grinding pads 4 with annular clearance grooves 41 on two grinding discs, and opens a groove at a specific position on the planetary disk 1. The two mobile phone back panels are fixed to the same planetary disk 1 facing each other using a clamp 5. When the double-sided grinding machine is used to grind the outer surface of the mobile phone back panel, the two grinding discs revolve around each other, and the planetary disk 1 and the two mobile phone back panels it supports rotate coaxially. During the rotation of the mobile phone back panel, the crater is always in the annular clearance groove 41 of the corresponding side grinding pad 4, and is in a suspended state, so it will not be damaged by grinding.

[0055] The mobile phone back panels prepared in the following embodiments and comparative examples are from the same batch of mobile phone back panels produced, and the material is zirconium oxide ceramic.

[0056] Example 1

[0057] This embodiment provides a surface treatment method for the back panel of an irregularly shaped mobile phone, including the following steps:

[0058] (1) Prepare the phone back cover;

[0059] (2) Use a grinding wheel to polish the outer surface of the frame of the mobile phone back panel to remove the burrs on the outer surface of the frame;

[0060] (3) Use a grinding wheel to polish the outer surface of the back panel of the mobile phone.

[0061] (4) The outer surface of the back panel of the mobile phone is machined using a CNC machine tool; the cutting tool of the CNC machine tool is a diamond grinding head;

[0062] (5) Prepare the fixture. Two mobile phone back panels are a group and are respectively installed into the two mounting slots 51 of the same fixture 5, so that the edge of the mobile phone back panel is inserted into the corresponding groove 52. Then, the fixture 5 with the mobile phone back panel is installed into the empty slot of the planetary disk 1. The two mobile phone back panels face each other and are staggered. The central axis of the crater of the two mobile phone back panels coincides with the central axis of the planetary disk 1. The crater of the mobile phone back panel corresponds to the annular clearance groove 41 of the grinding pad 4.

[0063] Start the double-sided grinding machine to grind the outer surface of the phone's back panel;

[0064] (6) The back panel of the mobile phone after grinding in step S4 is polished using a multi-axis machine and diamond polishing liquid to remove the grinding wheel marks on the crater-shaped part of the back panel of the mobile phone. The particle size of the abrasive in the diamond polishing liquid is 35um.

[0065] (7) Polish the back panel of the mobile phone after step S51 using a brush and diamond polishing liquid. The particle size of the abrasive in the diamond polishing liquid is 8 μm.

[0066] (8) The mobile phone back panel after step S52 is subjected to a light-sweeping treatment using a brush and silica sol solution to obtain the finished mobile phone back panel. The particle size of the silica sol in the silica sol solution is 100nm.

[0067] The clamp 5 used is an elastic clamp, and the hardness of the elastic clamp is shown in Table 1.

[0068] The width of the mounting groove 51 is denoted as W, the length of the mounting groove 51 is denoted as L, the width of the annular clearance groove 41 is denoted as B, the maximum width of the crater is denoted as D, the length of the cutting area on the outer surface of the back panel body in step S3 is denoted as l, and the width of the mobile phone back panel is denoted as w. BD, Ww, and Ll are shown in Table 1.

[0069] The process parameters for each step from (4) to (8) are shown in Table 2.

[0070] Examples 2-15 and Comparative Examples 1-8

[0071] Examples 2-15 and Comparative Examples 1-8 respectively provide a surface treatment method for the back panel of a mobile phone with an irregular structure. The difference between Examples 2-15 and Comparative Examples 1-8 and Example 1 is that the hardness, BD, Ww, and Ll of the fixtures used in Examples 2-15 and Comparative Examples 1-8 are shown in Table 1.

[0072] Examples 16-18

[0073] Examples 16-18 provide a surface treatment method for the back panel of a mobile phone with an irregular structure. The difference between Examples 16-18 and Example 1 is that the process parameters of each process in steps (4) to (8) of Examples 16-18 are shown in Table 2.

[0074] Table 1

[0075]

[0076]

[0077] Table 2

[0078]

[0079]

[0080] Example of effect 1

[0081] The ceramic backplates of the above embodiments and comparative examples were subjected to the following tests:

[0082] (1) Clean the finished product using a cleaning line;

[0083] (2) The inspector wears finger cots and inspects the finished products according to the requirements of the inspection card. The quantity of each finished product is 100 pieces. All inspections are carried out manually by visually comparing with the limit sample. There may be some defects in the limit sample that meet the requirements (i.e. defects that can be removed in the subsequent further processing).

[0084] ① If the number and size of grinding wheel line defects in the finished product exceed those in the limit sample, then the finished product is a grinding wheel line defective product; calculate the grinding wheel line defect rate according to the following formula: Grinding wheel line defect rate = number of grinding wheel line defective products / total number of finished products * 100%;

[0085] ② If the number and size of scratches in the finished product exceed those of the limit sample, the finished product is a scratch defective product; the scratch defect rate is calculated according to the following formula: Scratch defect rate = Number of scratch defective products / Total number of finished products * 100%;

[0086] ③ If the number and size of overcut defects in the finished product exceed those in the limit sample, then the finished product is an overcut defective product; calculate the overcut defect rate according to the following formula: Overcut defect rate = Number of overcut defective products / Total number of finished products * 100%;

[0087] ④ If the number and size of the cracked defects in the finished product exceed those in the limit sample, then the finished product is a cracked defective product; calculate the cracked defect rate according to the following formula: Cracked defect rate = Number of cracked defective products / Total number of finished products * 100%;

[0088] ⑤ If the characteristics of each of the defects in the finished product, such as grinding wheel lines, scratches, overcuts, and cracks, do not exceed the characteristics of the corresponding defects on the limit sample, the finished product can be considered as qualified; calculate the appearance qualification rate according to the following formula: Appearance qualification rate = Number of qualified products / Total number of finished products * 100%;

[0089] The appearance qualification rate of finished products should not be less than 68%; the failure rate of grinding wheel lines and scratches is not mandatory, because grinding wheel lines and scratches can be repaired, but the lower the failure rate of grinding wheel lines and scratches, the better; the overcut failure rate should be less than 10%, and the chip failure rate should be less than 5%.

[0090] The test results are shown in Table 3.

[0091] Table 3

[0092]

[0093]

[0094] As shown in Table 3, the appearance qualification rate of the ceramic back panel products processed by the embodiments of the present invention is not less than 68%, and the defect rates of grinding wheel lines, scratches, overcutting and cracks are low. This indicates that the present invention, by using a fixture with suitable hardness, controls the size difference between the fixture mounting groove and the mobile phone back panel within an appropriate range, and controls the width difference between the annular clearance groove of the grinding pad and the crater within an appropriate range, can effectively remove defects such as grinding wheel lines, scratches, overcutting and cracks left on the surface of the mobile phone back panel by the previous process during grinding.

[0095] Compared with the examples, the fixture used in Comparative Example 1 had too low a hardness, while the fixture used in Comparative Example 2 had too high a hardness. During grinding, the grinding wheel lines could not be effectively removed, resulting in a significant decrease in the pass rate of the finished product and a significant increase in the grinding wheel line defect rate.

[0096] Compared with the embodiments, in Comparative Example 3, the width B of the annular clearance groove is smaller than the maximum width D of the crater. Since the crater protrudes from the back panel of the mobile phone, the crater outside the annular clearance groove is ground during grinding, while other areas of the back panel of the mobile phone cannot fully contact the grinding pad during the grinding process. This cannot effectively remove defects such as grinding wheel lines, scratches, overcuts, and cracks from the surface of the back panel of the mobile phone. When Comparative Example 3 inspected the overcut defects of the finished product, it was found that the overcut defect rate reached 100%. In Comparative Example 4, BD > 2. During grinding, the area of ​​the suspended part around the crater is large, and the suspended part is not ground. As a result, the overcut and crack defects around the crater protrusion are retained, which seriously affects the pass rate of the finished product.

[0097] Although Comparative Examples 6 and 8 use elastic clamps, the mounting slots of the clamps in Comparative Examples 6 and 8 are too small relative to the back panel of the mobile phone. Therefore, the back panel of the mobile phone cannot be installed into the mounting slot of the clamp in step (5), and thus the grinding process cannot be performed.

[0098] Compared to the mobile phone back panel, the mounting slots of the fixtures in Comparative Examples 5 and 7 are too large. Although this improves the yield rate of the finished product, in order to ensure that the strength of the planetary disk is not affected, the loading of the mobile phone back panel on the planetary disk can only be reduced, which reduces the processing efficiency of the mobile phone back panel.

[0099] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for surface treatment of irregularly shaped mobile phone back panels, characterized in that, Includes the following steps: S1. Prepare a mobile phone back panel, which includes a frame and a back panel body, and the back panel body is provided with a volcano-shaped opening. S2. Polish the outer surface of the mobile phone back panel; S3. Use a CNC machine tool to cut and process the outer surface of the phone back panel; S4. Use a double-sided grinding machine to grind the outer surface of the phone back panel; The planetary transmission mechanism of the double-sided grinding machine includes a lower grinding disc, a planetary disk, and a sun gear. Both the upper and lower grinding discs of the double-sided grinding machine are provided with grinding pads. The grinding pads are provided with annular clearance grooves. The lower grinding disc is coaxially arranged with the sun gear. A gear ring is provided on the outer periphery of the lower grinding disc. The planetary disk meshes with the gear ring and meshes with the sun gear. The planetary disk is provided with a slot adapted to the clamp. The center point axis of the planetary disk passes through the slot. Before step S4, the following steps are also included: using the clamp to fix two mobile phone back panels to the slot of the planetary disk. The two mobile phone back panels face each other and are staggered. The crater of the mobile phone back panel corresponds to the annular clearance groove of the grinding pad. The central axis of the crater of the two mobile phone back panels coincides with the central axis of the planetary disk. The central axis of the planetary disk intersects the center circle of the two annular clearance grooves. During the grinding process, the crater of the mobile phone back panel is accommodated in the corresponding annular clearance groove. S5. Polish the back panel of the phone to obtain the finished phone back panel.

2. The method of claim 1, wherein the surface treatment of the profiled cell phone backplane is performed by a process selected from the group consisting of: chemical etching, mechanical etching, and a combination thereof. Step S2 includes: S21. Use a grinding wheel to polish the outer surface of the frame of the mobile phone back panel to remove the burrs on the outer surface of the frame. S22. Use a grinding wheel to polish the outer surface of the back panel of the mobile phone.

3. The method of claim 1, wherein the surface treatment of the profiled cell phone backplane is performed by a process selected from the group consisting of: chemical etching, mechanical etching, and a combination thereof. The CNC machine tool uses diamond grinding heads with a diameter of 8-40 mm and a mesh size of 80-130. The distance between any two adjacent grinding heads is 0.01-0.06 mm.

4. The surface treatment method for irregularly shaped mobile phone back panels as described in claim 1, characterized in that, Step S3 controls the CNC machine tool's cutting speed to 10000~15000 r / min, the machining removal amount to 0.15~0.2 mm, and the machining dimensional accuracy to ±0.05 mm.

5. The surface treatment method for irregularly shaped mobile phone back panels as described in claim 1, characterized in that, In step S4, the rotation speed of the double-sided grinding machine is 25~35 r / min, the amount of material removed is 0.02~0.05 mm, and the grinding pressure is 10~15 Kg / piece.

6. The method of claim 1, wherein the surface treatment of the profiled cell phone backplane is performed by a process selected from the group consisting of: chemical etching, mechanical etching, and a combination thereof. The clamp is an elastic clamp with a hardness of 35~50HD.

7. The method of claim 1, wherein the surface treatment is performed by a process selected from the group consisting of: sanding, buffing, and polishing. The width B of the annular vent groove and the maximum outer diameter D of the crater satisfy the following condition: 0mm < BD ≤ 2mm.

8. The surface treatment method for irregularly shaped mobile phone back panels as described in claim 1, characterized in that, Step S5 specifically includes: S51. A multi-axis machine tool is used to polish the back panel of the mobile phone after grinding in step S4. S52. Polish the back panel of the mobile phone after step S51 using a brush and a first polishing liquid. S53. The mobile phone back panel after step S52 is polished using a brush and a first polishing liquid to obtain the finished mobile phone back panel.

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