Stripping method
By forming an oxide layer on the titanium surface to increase the resistance of the second conductive component, the stripping time of the second film layer is extended, which solves the corrosion problem caused by the inconsistent film thickness in different areas of the mobile phone frame during the stripping process. This enables the complete stripping and reuse of the frame and reduces production costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- LANKAO YUZHAN INTELLIGENT MFG TECH CO LTD
- Filing Date
- 2023-12-26
- Publication Date
- 2026-06-12
AI Technical Summary
During the process of removing the plating from the mid-frame of a mobile phone, the thickness and area of the film layer in different areas of the mid-frame are inconsistent, resulting in differences in the plating removal time. This causes the areas that are removed completely first to be corroded, affecting the surface smoothness and appearance, making them difficult to reuse.
A second conductive component with higher resistance is used. The resistance is increased by forming an oxide layer on the titanium surface and connecting it to a second film layer with a smaller area or thickness. This extends the stripping time, reduces the time gap between the stripping of the first film layer and the complete stripping of the first film layer, and prevents the socket ring from being corroded.
It effectively reduces or eliminates the possibility of corrosion of the socket ring, ensures the flatness and appearance quality of the middle frame surface, enables the reuse of the middle frame, and reduces production costs.
Smart Images
Figure CN117926255B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of plating removal technology, and more particularly to a plating removal method. Background Technology
[0002] Coating technology has wide applications in the industrial field. During the production of mobile phone frames, if the surface coating on the frame does not meet product quality requirements, it needs to be removed and re-coated for reuse, thus saving costs.
[0003] Due to the influence of the product on the appearance of the mid-frame and the coating process, the area or thickness of the coating layer in different areas of the mid-frame is inconsistent. During the stripping process, there will be differences in the stripping time. The areas of the mid-frame that are stripped completely first are exposed to the stripping solution and are under electrolytic conditions. These areas are corroded, which affects the surface flatness and appearance of the entire mid-frame, making it impossible to recoat the mid-frame. Summary of the Invention
[0004] In view of this, it is necessary to provide a method for removing plating that improves the corrosion of the workpiece substrate in order to solve the above problems.
[0005] A method for removing plating is provided for removing a first film layer and a second film layer from the substrate surface of a mobile phone frame. The substrate includes a frame and a socket ring. A through hole is formed on the frame, and the socket ring is insulated and embedded in the through hole. The first film layer is located on the surface of the frame, and the second film layer is located on the surface of the socket ring. The thickness and / or area of the first film layer is greater than the thickness and / or area of the second film layer. The method includes: connecting one end of a first conductive element to the frame; connecting one end of a second conductive element to the socket ring, wherein the resistance of the second conductive element is greater than the resistance of the first conductive element, and the second conductive element includes a body and an oxide layer located on the surface of the body, wherein the resistance of the oxide layer is greater than the resistance of the body; connecting the other ends of the first and second conductive elements to the positive terminal of a power supply, connecting the counter electrode to the negative terminal of the power supply, and placing the frame in a plating removal solution for plating removal to remove the first and second film layers.
[0006] In some embodiments, both the body and the first conductive element are made of titanium.
[0007] In some embodiments, the stripping method includes, before connecting the frame with the first conductive element, the step of anodizing the titanium sheet to generate an oxide layer and forming the second conductive element.
[0008] In some embodiments, before the step of stripping in the stripping solution, one end of the second conductive element is inserted into the through hole and contacts the second film layer.
[0009] In some implementations, the socket ring and the frame are connected in parallel to the same power supply.
[0010] In some embodiments, the thickness of the oxide layer is less than 5 μm and greater than 0.
[0011] In some embodiments, the resistivity of the oxide layer is 1Ω / m-10Ω / m.
[0012] In some implementations, the stripping temperature is 10°C-40°C.
[0013] In some implementations, the frame is made of stainless steel, and the socket ring is made of titanium or titanium alloy.
[0014] In some embodiments, the substrate further includes a middle plate with a frame surrounding the periphery of the middle plate. The middle plate is made of aluminum or an aluminum alloy and has an anodized film on the surface of the aluminum or aluminum alloy. The middle plate is exposed to a first film layer and a second film layer.
[0015] The stripping method provided in this application uses a second conductive element with an oxide layer to increase the resistance of the second conductive element. During the stripping process, the second conductive element is used to connect a second film layer with a smaller area or thickness to reduce the current passing through the second film layer and extend the time for the second film layer to be completely stripped, thereby reducing or eliminating the time difference between the second film layer and the first film layer to be completely stripped, and thus reducing or eliminating the possibility of corrosion of the socket ring. Attached Figure Description
[0016] Figure 1 This is a schematic diagram of the structure of the middle frame before deplating, provided in an embodiment of this application.
[0017] Figure 2 This is a partial cross-sectional schematic diagram of the middle frame before deplating, provided in an embodiment of this application.
[0018] Figure 3 A flowchart of the plating removal method provided in the embodiments of this application.
[0019] Figure 4 This is a schematic diagram of the structure of the second conductive element inserted into the through hole provided in an embodiment of this application.
[0020] Figure 5 for Figure 4 The diagram shows a cross-sectional view of the second conductive element along the IV-IV direction.
[0021] Figure 6 This is a schematic diagram illustrating the principle of electrolytic stripping provided in an embodiment of this application.
[0022] Figure 7 Images are of partial areas of the substrates obtained after deplating in the embodiments and comparative examples of this application.
[0023] Explanation of main component symbols
[0024] Detailed Implementation
[0025] To better understand the above-mentioned objectives, features, and advantages of this application, the application will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. Many specific details are set forth in the following description to provide a thorough understanding of this application; the described embodiments are merely some, not all, of the embodiments described in this application.
[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The term "and / or" as used herein includes all and any combination of one or more of the associated listed items.
[0027] In the various embodiments of this application, for ease of description and not limitation, the term "connection" used in the patent application specification and claims is not limited to physical or mechanical connections, whether direct or indirect. Terms such as "upper," "lower," "above," "below," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship also changes accordingly.
[0028] Please see Figure 1 and Figure 2 , Figure 1 This is a schematic diagram of the structure of the mobile phone frame 100 before deplating, as provided in an embodiment of this application. Figure 2 This is a partial cross-sectional schematic diagram along the thickness direction of the mid-frame 100. This application provides a method for removing the first film layer 21 and the second film layer 23 from the surface of the substrate 10 of the mid-frame 100 of a mobile phone.
[0029] Specifically, the middle frame 100 includes a frame 11, a socket ring 13, and a middle plate 15. The frame 11 surrounds the periphery of the middle plate 15. The middle plate 15 is formed of an aluminum-containing sheet and an anodized film formed on the surface of the sheet. The surface of the middle plate 15 does not have a first film layer 21 or a second film layer 23. The material of the frame 11 includes stainless steel. A through hole 112 is provided on the frame 11, and the socket ring 13 is insulated and embedded in the through hole 112. The material of the socket ring 13 is typically titanium alloy. The socket ring 13 serves as a charging port for the mobile phone. The socket ring 13 is insulated from the frame 11 by an insulating layer 17 to prevent the frame 11 and the middle plate 15 from conducting during the charging process. In this embodiment, the main components of the first film layer 21 and the second film layer 23 include cadmium oxide. During the deposition process to form the first film layer 21 and the second film layer 23, the thickness of the second film layer 23 on the surface of the socket ring 13 gradually decreases as the socket ring 13 is penetrated deeper. The inner side of the socket ring 13 is difficult to detect. The connection between the socket ring 13 and the frame 11 is a high-gloss chamfered area of the middle frame 100. The substrate 10 in this area is easily corroded during the stripping process, and the roughness of the high-gloss chamfered area is lower than other areas. Corrosion in this area significantly affects the appearance.
[0030] The first film layer 21 and the second film layer 23 are located on the surface of the frame 11, and the second film layer 23 is located on the surface of the insertion ring 13. The thickness and / or area of the first film layer 21 is greater than the thickness and / or area of the second film layer 23. Under the same stripping conditions, if both the first film layer 21 and the second film layer 23 are completely stripped, the time required to strip the first film layer 21 is greater than the time required to strip the second film layer 23. Therefore, during the stripping process, under the same stripping conditions, it is difficult for the first film layer 21 and the second film layer 23 to be completely removed simultaneously. When the second film layer 23 is completely removed, but the first film layer 21 is not completely removed, the surface of the substrate 10 covered by the second film layer 23 is exposed to the stripping solution and stripped simultaneously with the first film layer 21, resulting in corrosion of the substrate 10. The stripping method provided in this application embodiment can improve the phenomenon of corrosion of the substrate 10 during the stripping process.
[0031] In one specific embodiment, the area ratio of the first film layer 21 to the second film layer 23 is 40:1, and the roughness of the frame 11 is relatively large, resulting in a strong bond between the frame 11 and the first film layer 21. The roughness of the socket ring 13 is relatively small, resulting in a weak bond between the socket ring 13 and the second film layer 23. The time required for the first film layer 21 to be completely deplated is 60 minutes, and the time required for the second film layer 23 to be completely deplated is 15 minutes. Therefore, after the second film layer 23 is completely deplated, the socket ring 13 remains in an electrolytic state and needs to be etched for 45 minutes.
[0032] A first film layer 21 and a second film layer 23 can be formed on the surface of the substrate 10 using coating processes such as physical vapor deposition (PVD) and chemical vapor deposition (CVD). The first film layer 21 and the second film layer 23 can be formed in the same coating process and located in different regions of the substrate 10. The first film layer 21 and the second film layer 23 are located on the outer surface of the substrate 10 and can serve as the outer appearance layer of the middle frame 100. When defects occur during the coating process, a stripping process is required to remove the first film layer 21 and the second film layer 23 so that a new film layer can be coated on the stripped substrate 10. If the substrate 10 is corroded during the stripping process, it will affect the quality of the recoating and the appearance of the substrate 10, making it difficult to reuse the substrate 10. In the consumer electronics sector, the casing of electronic products often requires dozens or even hundreds of processes to balance performance and appearance. The 100% coating process for the mid-frame is generally a relatively late stage in the manufacturing process. If defective products in the coating process cannot be reprocessed, the costs of the preceding processes will be lost. Therefore, decoating is crucial for cost control throughout the entire electronic product casing manufacturing process.
[0033] Please refer to the following: Figure 3 The plating removal method provided in this application embodiment may include steps S1-S3.
[0034] Step S1: Connect one end of the first conductive element (not shown) to the frame 11.
[0035] In some specific embodiments, the first conductive element is a fixing element, that is, the first conductive element has both the function of electrical conduction and the function of fixing the middle frame 100 to facilitate the implementation of the stripping process. In this embodiment, the first conductive element is directly connected to the frame 11, and both the middle plate and the frame 11 are made of conductive materials, so the middle plate and the frame 11 can conduct electricity to each other.
[0036] The first conductive component is made of titanium. Titanium is a stable material with low resistance, good resistance to acids, alkalis, and corrosion, and can be reused multiple times.
[0037] Step S2: Connect one end of the second conductive element 40 (not shown) to the socket ring 13. The resistance of the second conductive element 40 is greater than the resistance of the first conductive element.
[0038] Please see Figure 4 and Figure 5The second conductive element 40 may include a body 41 and an oxide layer 43 formed on the surface of the body 41. The oxide layer 43 may be formed by oxidizing the material of the body 41. The resistance of the oxide layer 43 is greater than the resistance of the body 41. Compared to the body 41 alone as the second conductive element 40, the resistance of the second conductive element 40 increases after the oxide layer 43 is formed on the surface of the body 41. One end of the second conductive element 40 can be inserted into the through hole 112 and connected to the second film layer 23 on the surface of the insertion ring 13.
[0039] The body 41 is made of titanium, and the oxide layer 43 may be made of at least one of titanium dioxide (TiO2) and titanium tetroxide (Ti3O4). Both titanium dioxide (TiO2) and titanium tetroxide (Ti3O4) are stable, exhibit good resistance to acids, alkalis, and corrosion, and can be reused multiple times. The resistivity of titanium is approximately 5.56 × 10⁻⁶. -7 After forming an oxide layer 43 on the surface of titanium, the resistivity of the oxide layer 43 can be 1Ω / m-10Ω / m, thereby increasing the resistance of the second conductive element 40. Compared with other materials that have high resistance alone, the second conductive element 40, which uses titanium oxide to coat titanium, has good acid and alkali resistance, is not easily corroded under stripping conditions, has a long service life, can be reused multiple times, and reduces costs.
[0040] In some embodiments, the thickness of oxide layer 43 is less than 5 μm and greater than 0.
[0041] In this embodiment, titanium is anodized to form an oxide layer 43 on the surface, thereby obtaining the second conductive element 40.
[0042] Step S3: Connect the other end of the first conductive element and the other end of the second conductive element 40 to the positive terminal of the power supply, connect the counter electrode 30 to the negative terminal of the power supply, and place the middle frame 100 in the stripping solution for stripping so as to remove the first film layer 21 and the second film layer 23.
[0043] Please see Figure 6 Specifically, the middle frame 100 serves as the anode, and the counter electrode 30 serves as the cathode. The counter electrode 30 can be a stainless steel plate or a graphite plate. The frame 11 and the socket ring 13 are connected in parallel to the same power supply. Under the action of direct current, an oxidation reaction occurs at the anode, and the first film layer 21 and the second film layer 23 gradually dissolve from the substrate 10. The metals in the first film layer 21 and the second film layer 23 enter the stripping solution in the form of ions. A reduction reaction occurs at the cathode, where hydrogen is evolved or metal ions are reduced. The stripping temperature can be 10℃-40℃, and the stripping time can be 50min-90min.
[0044] In this embodiment, the second conductive element 40 includes an oxide layer 43 with higher resistance. The resistance of the second conductive element 40 is greater than that of the first conductive element. Under the same voltage, the current passing through the socket ring 13 is less than the current passing through the frame 11. Therefore, the stripping rate of the second film layer 23 is less than that of the first film layer 21, effectively extending the time required for the second film layer 23 to completely strip, thereby reducing or eliminating the time difference between the complete stripping of the second film layer 23 and the first film layer 21, and thus reducing or eliminating the possibility of corrosion of the socket ring 13. The surface of the middle plate 15 is exposed to the first film layer 21 and the second film layer 23. Since the surface of the middle plate 15 is an anodized aluminum film, the anodized aluminum film has stable properties and will not corrode under stripping conditions.
[0045] Theoretical calculations illustrate this. For example, if the stripping voltage for each middle frame 100 is 0.0125V, then the current passing through the frame 11 is 22482A. Assuming the resistivity of the oxide layer 43 is 5Ω / m, the current passing through the socket ring 13 is 0.0025A, effectively reducing the current passing through the socket ring 13. It should be noted that the actual stripping rate is also affected by factors such as the material of the films (i.e., the first film layer 21 and the second film layer 23), the area of the films being stripped, and the position of the films.
[0046] The present application will be described below through specific embodiments and comparative examples. Both embodiments and comparative examples test multiple mid-frames 100 to test yield.
[0047] Comparative Example
[0048] A middle frame 100 is provided, with a first conductive element and a second conductive element 40 connected to the frame 11 and the socket ring 13 respectively. Both the second conductive element 40 and the first conductive element are made of titanium, and they form a circuit with the battery to perform stripping in the stripping solution. After the first film layer 21 and the second film layer 23 are completely stripped, the substrate 10 after stripping is observed.
[0049] Example
[0050] Unlike the comparative example, the second conductive element 40 in this embodiment is made of titanium and titanium dioxide and titanium tetroxide on the surface of the titanium.
[0051] Please see Figure 7 , Figure 7 Image (a) is an image of a portion of the base 10 of the middle frame 100 after it has been eroded. Figure 7Image (b) shows an uncorroded portion of the substrate 10 of the middle frame 100. After testing with multiple embodiments and comparative examples, the yield of the comparative examples was approximately 74.79%, and 25.21% of the middle frames 100 were corroded after plating removal, making the substrate 10 difficult to reuse. The yield of the embodiments was 100%, meaning that all middle frames 100 could be reused after plating removal using the method described in the embodiments.
[0052] The stripping method provided in this application embodiment increases the resistance of the second conductive element 40, which is provided with an oxide layer 43. During the stripping process, the second conductive element 40 is used to connect the second film layer 23, which has a smaller area or thickness, so as to reduce the current passing through the second film layer 23 and prolong the time for the second film layer 23 to be completely stripped, thereby reducing or eliminating the time difference between the second film layer 23 and the first film layer 21 to be completely stripped, and thus reducing or eliminating the possibility of corrosion of the socket ring 13.
[0053] The above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to the above preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of this application should not depart from the spirit and scope of the technical solutions of this application.
Claims
1. A method for removing plating, used to remove a first film layer and a second film layer from the surface of a substrate of a mobile phone frame, the substrate including a frame and a socket ring, the frame having a through hole, the socket ring being insulatedly embedded in the through hole, the first film layer being located on the surface of the frame, the second film layer being located on the surface of the socket ring, the thickness and / or area of the first film layer being greater than the thickness and / or area of the second film layer, wherein... The plating removal method includes: Connect one end of the first conductive element to the frame; One end of the second conductive element is connected to the socket ring. The resistance of the second conductive element is greater than that of the first conductive element. The second conductive element includes a body and an oxide layer on the surface of the body, and the resistance of the oxide layer is greater than that of the body. The other end of the first conductive element and the other end of the second conductive element are both connected to the positive terminal of the power supply, and the counter electrode is connected to the negative terminal of the power supply. The middle frame is placed in the stripping solution for stripping to remove the first film layer and the second film layer.
2. The plating stripping method according to claim 1, wherein, Both the main body and the first conductive component are made of titanium.
3. The plating removal method according to claim 2, wherein, The stripping method includes, before connecting the frame with the first conductive element, the step of anodizing the titanium sheet to generate the oxide layer and forming the second conductive element.
4. The plating stripping method according to claim 1, wherein, Before the step of placing the second conductive element in the stripping solution for stripping, one end of the second conductive element is inserted into the through hole and contacts the second film layer.
5. The plating stripping method according to claim 1, wherein, The socket ring and the frame are connected in parallel to the same power supply.
6. The plating stripping method according to claim 1, wherein, The thickness of the oxide layer is less than 5 μm and greater than 0.
7. The plating stripping method according to claim 1, wherein, The resistivity of the oxide layer is 1Ω / m-10Ω / m.
8. The plating stripping method according to claim 1, wherein, The stripping temperature is 10℃-40℃.
9. The plating stripping method according to any one of claims 1-8, wherein, The frame is made of stainless steel, and the socket ring is made of titanium or titanium alloy.
10. The plating stripping method according to claim 9, wherein, The substrate further includes a middle plate, the frame is disposed around the periphery of the middle plate, the middle plate is made of aluminum or aluminum alloy and an anodized film on the surface of the aluminum or aluminum alloy, and the middle plate is exposed to the first film layer and the second film layer.