A mask electrolytic machining method

Abstract

This invention discloses a mask electrolytic machining method in the field of mask processing technology. The method includes: acquiring a metal workpiece with a polyimide film prepared on its surface; patterning the polyimide film according to first laser direct writing process parameters to obtain an exposed metal workpiece; performing secondary laser direct writing processing on the exposed edge of the polyimide film according to second laser direct writing process parameters, generating a graphene structure connected to the metal workpiece within a range that can induce graphene generation on the exposed edge of the polyimide film; and controlling the laser beam movement path of the laser electrolytic platform to reciprocate in the exposed area of ​​the metal workpiece to complete the machining. This invention can solve the technical problems existing in the current mask electrolytic machining technology, such as the electric field concentration effect, which causes the removal of material within the unit to be "island-like", and the isotropic electrolytic corrosion leading to reduced processing localization, making it difficult to form microstructures with large aspect ratios.

Description

Technical Field

[0001] This invention relates to the field of mask processing technology, and more particularly to a mask electrolytic processing method. Background Technology

[0002] Surface microtexturing technology utilizes micro- and nano-fabrication methods to prepare arrays of microstructures with specific shapes and arrangements on the surface of materials, thereby controlling the surface properties of the materials. Studies have shown that microtexturing the surface of materials can effectively improve its wettability, capillary force, biocompatibility, friction and wear resistance, corrosion resistance, and biocompatibility, attracting significant attention in fields such as aerospace, biomedicine, and high-end electronics.

[0003] Currently, the main processing methods for functional microtextures on the surface of metallic materials include micromilling, laser processing, electrical discharge machining (EDM), and mask electrochemical machining. Compared with other processing methods, mask electrochemical machining exhibits significant advantages in terms of the absence of a heat-affected zone, a modified layer, and burrs on the processed surface, the fact that the processing is unaffected by the mechanical properties of the material, and the absence of tool electrode wear.

[0004] In traditional mask electrochemical etching, due to the insulating properties of the mask material, an electric field concentration effect inevitably occurs at the edges of the pattern units. This results in the material removal within the unit appearing as "islands," meaning the etched surface within the mask unit is high in the middle (slow etching) and low at both sides (concentrated electric field, fast etching rate). Furthermore, isotropic electrochemical etching reduces the localization of the process, making it difficult to form microstructures with large aspect ratios.

[0005] Therefore, there is an urgent need for a mask electrolytic processing method, apparatus, and storage medium to solve the above-mentioned technical problems. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a mask electrolytic processing method, apparatus and storage medium that can solve the technical problems of electric field concentration effect in the existing mask electrolytic processing technology, which causes the removal of material in the unit to be in the form of "islands", and isotropic electrolytic corrosion that reduces the localization of processing, making it difficult to form microstructures with large aspect ratio.

[0007] To achieve the above objectives, the present invention is implemented using the following technical solution:

[0008] In a first aspect, the present invention provides a mask electrolytic processing method, which processes the material using a laser electrolytic platform. The laser electrolytic platform integrates a tool electrode, which is connected to the negative terminal of a power supply. The method includes:

[0009] Obtain a metal workpiece with a polyimide film on its surface;

[0010] The polyimide film is patterned according to the preset first laser direct writing process parameters to obtain an exposed metal workpiece, wherein the exposed area of ​​the metal workpiece corresponds to the patterned area.

[0011] According to the preset second laser direct writing process parameters, the exposed edge of the polyimide film is subjected to secondary laser direct writing processing. Within the range that can induce graphene generation on the exposed edge of the polyimide film, a graphene structure connected to the metal workpiece is generated. Both the metal workpiece and the graphene structure are connected to the positive electrode of the power supply.

[0012] The laser beam motion path of the laser electrolysis platform is set to be located within the exposed area of ​​the metal workpiece, and the laser beam motion path of the laser electrolysis platform is controlled to reciprocate within the exposed area of ​​the metal workpiece to complete the processing.

[0013] Furthermore, obtaining a metal workpiece with a polyimide film on its surface includes:

[0014] A polyimide solution is uniformly coated onto the surface of a metal workpiece, and then subjected to thermosetting treatment to obtain a polyimide film.

[0015] The polyimide film is horizontally adhered to the surface of the metal workpiece using polyimide tape.

[0016] Furthermore, before obtaining a metal workpiece with a polyimide film prepared on its surface:

[0017] The metal workpiece was ultrasonically cleaned and dried using acetone, anhydrous ethanol, and deionized water, respectively.

[0018] Furthermore, it also includes:

[0019] Nanoscale structures are pre-fabricated on the surface of metal workpieces using laser processing.

[0020] Furthermore, it also includes:

[0021] After electrolytic machining, the surface mask is removed, and the metal workpiece is ultrasonically cleaned using a disinfectant solution.

[0022] Furthermore, both the first and second laser direct writing process parameters are set based on the ablation threshold of the polyimide film.

[0023] Furthermore, for microstructure machining of metal workpiece surfaces, when used for microstructure machining of metal workpiece surfaces, the reciprocating motion includes:

[0024] Based on the preset laser beam motion path and speed, the workpiece is controlled by the motion platform to reciprocate along the horizontal direction.

[0025] Furthermore, for machining hollow structures on metal workpieces, when used for machining hollow structures on metal workpieces, the reciprocating motion includes:

[0026] According to the preset laser beam motion path and speed, the workpiece is driven to rotate continuously around its own axis by the rotating platform, and the tool electrode on the laser electrolysis platform is controlled to reciprocate along the axis of the metal workpiece until the electrolysis process forms a hollow pattern.

[0027] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0028] This invention proposes a mask electrochemical machining method. After obtaining a metal workpiece with a polyimide film on its surface, the polyimide film is patterned according to preset first laser direct writing process parameters to obtain an exposed metal workpiece. Then, a second laser direct writing process is performed on the exposed edge of the polyimide film according to preset second laser direct writing process parameters. This generates a graphene structure connected to the metal workpiece at the exposed edge of the polyimide film. The graphene structure, connected to the surface of the metal workpiece, can serve as a sacrificial anode in subsequent electrochemical machining, improving the localization of the electrochemical machining and forming microstructures with a large aspect ratio. By adjusting the second laser direct writing process parameters, flexible in-situ fabrication of sacrificial anodes with different widths, conductivity, and wettability can be achieved at the exposed edge of the polyimide film. Attached Figure Description

[0029] Figure 1 This is a flowchart of a mask electrolytic processing method provided in Embodiment 1 of the present invention;

[0030] Figure 2 This is a schematic diagram of the process from the first step to the third step in a mask electrolytic processing method provided in Embodiment 1 of the present invention;

[0031] Figure 3 This is a schematic diagram of the process from step four to step five in a mask electrolytic processing method provided in Embodiment 1 of the present invention;

[0032] Figure 4 This is a schematic diagram of the hollowing process in a mask electrolytic machining method provided in Embodiment 2 of the present invention;

[0033] Figure 5 This is a schematic diagram of a specific process in a mask electrolytic processing method provided in Embodiment 2 of the present invention;

[0034] Among them, 1. metal workpiece; 2. polyimide film; 3. polyimide film pattern unit; 4. exposed edge of polyimide film; 5. graphene structure; 6. tool electrode; 7. narrow slit; 8. laser beam motion path. Detailed Implementation

[0035] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments and specific features in the embodiments are detailed descriptions of the technical solution of the present application, rather than limitations thereof. In the absence of conflict, the embodiments and technical features in the embodiments can be combined with each other.

[0036] In this invention, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A alone, A and B together, or B alone. Additionally, in this invention, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0037] The mask electrolytic processing method mentioned in the Specific Embodiments section of this application is processed by a laser electrolytic platform. The laser electrolytic platform is existing technology and will not be described in detail here. In the specific real-time method section disclosed in this application, it only serves the function of laser electrolytic processing. The laser electrolytic platform integrates a tool electrode 6, which is connected to the negative terminal of the power supply.

[0038] Specifically, in this application, a metal foil such as stainless steel with a certain width can be used as the tool electrode 6, and a narrow slit 7 can be processed in situ on the tool electrode 6 by laser processing to prevent subsequent laser transmission.

[0039] To facilitate understanding, some of the proper nouns mentioned in this application will be explained:

[0040] Polyimide (PI) is a class of high-performance polymer materials, known for its excellent high-temperature resistance, mechanical strength, chemical stability and electrical insulation properties. It is widely used in high-tech fields such as aerospace, electronics, microelectronics and automobiles.

[0041] The ablation threshold of PI (polyimide) material refers to the critical energy density at which significant ablation (material removal) begins to occur under the action of high-energy lasers or plasmas. Example 1:

[0042] Figure 1 This is a flowchart of the mask electrolytic processing method according to Embodiment 1 of the present invention. This flowchart merely illustrates the logical sequence of the methods described in this embodiment. Provided there are no conflicts, different methods may be used in other possible embodiments of the present invention. Figure 1 Complete the steps shown or described in the order indicated.

[0043] The mask electrolytic processing method provided in this embodiment can be applied to a terminal and can be executed by a mechanical equipment fault identification device. This device can be implemented in software and / or hardware and can be integrated into the terminal, such as any smartphone, tablet, or computer device with communication capabilities. The method in this embodiment specifically includes the following steps:

[0044] Step 1: Obtain a metal workpiece 1 with a polyimide film on its surface:

[0045] The polyimide solution is uniformly coated onto the surface of the metal workpiece 1 by spin coating, spraying or other methods, and then subjected to heat curing treatment to obtain the polyimide film 2.

[0046] Using equipment such as a coating machine, the polyimide film 2 is horizontally pasted onto the surface of the metal workpiece 1 with polyimide tape to obtain the metal workpiece 1 with the polyimide film 2 on its surface.

[0047] In addition, before obtaining the metal workpiece 1 with the polyimide film 2 on its surface, the metal workpiece 1 can be ultrasonically cleaned and dried with acetone, anhydrous ethanol and deionized water, respectively.

[0048] In addition, before obtaining the metal workpiece 1 with the polyimide film 2 on its surface, a nanoscale structure can be pre-prepared on the surface of the metal workpiece 1 by laser processing. By increasing the contact area between the film and the metal workpiece 1, and at the same time utilizing the surface effect of the nanostructure, the interfacial bonding strength between the PI mask (i.e., the polyimide film 2 mentioned in this application) and the metal workpiece 1 substrate can be improved.

[0049] Step 2: The polyimide film 2 is patterned according to the preset first laser direct writing process parameters to obtain the exposed metal workpiece 1. The exposed area of ​​the metal workpiece 1 corresponds to the patterned area, i.e., the polyimide film pattern unit 3.

[0050] Step 3: Perform a second laser direct writing process on the exposed edge 4 of the polyimide film according to the preset second laser direct writing process parameters. Within the range that can induce graphene generation on the exposed edge 4 of the polyimide film, generate a graphene structure 5 connected to the metal workpiece 1. Both the metal workpiece 1 and the graphene structure 5 are connected to the positive terminal of the power supply.

[0051] It should be noted that the graphene structure 5 is connected to the surface of the metal workpiece 1, and can serve as a sacrificial anode in the subsequent electrolytic processing, which can improve the localization of electrolytic processing and form a microstructure with a large aspect ratio.

[0052] Among them, sacrificial anode is an electrochemical protection technology used to prevent metal corrosion. Its core principle is to use the difference in electrode potential between two metals in an electrolyte to make the anode metal, as the "sacrifice", corrode preferentially, thereby protecting the protected metal (cathode) from damage.

[0053] It should be noted that the processes of processing the polyimide film pattern unit 3 and processing the sacrificial anode on its edge are both completed in the same processing system. No secondary clamping is required; only the processing path in the system needs to be changed. This can avoid positioning errors and improve accuracy.

[0054] Step 4: Set the laser beam motion path 8 of the laser electrolysis platform to be located in the exposed area of ​​the metal workpiece 1, and control the laser beam motion path 8 of the laser electrolysis platform to reciprocate in the exposed area of ​​the metal workpiece 1 to complete the processing.

[0055] It should be noted that the first and second laser direct writing process parameters mentioned in this application can be adjusted according to actual application needs.

[0056] After electrolytic machining, the surface mask is removed, and the metal workpiece 1 is ultrasonically cleaned using a disinfectant such as alcohol or deionized water.

[0057] It should be noted that both the first and second laser direct writing process parameters are set based on the ablation threshold of the polyimide film.

[0058] The mask electrochemical machining method provided in this embodiment can be used for microstructure machining on the surface of a metal workpiece 1. When used for microstructure machining on the surface of a metal workpiece 1, the reciprocating motion includes:

[0059] According to the preset laser beam motion path 8 and motion speed, the metal workpiece 1 is controlled by the motion platform to reciprocate along the horizontal direction.

[0060] More specifically, regarding the mask electrolytic processing method disclosed in this application, such as... Figure 2 and Figure 3 As shown:

[0061] (1) Use 0.2mm thick aluminum sheet as metal workpiece 1, and clean it with acetone, anhydrous ethanol and deionized water for 5 minutes each and dry it with cold air.

[0062] (2) Set the ultraviolet nanosecond laser energy density to 2~3J / cm2, the scanning spacing to 10μm, and the scanning speed to 30mm / s, and perform nanotexturing treatment on the surface of the metal workpiece 1 to improve the bonding strength between the subsequent mask and the substrate.

[0063] (3) Use 0.035mm thick polyimide tape as a mask material and use a laminating machine to horizontally attach it to the surface of the metal workpiece 1.

[0064] (4) Mount the metal workpiece 1 on the laser electrolysis platform. Based on the characteristics of PI material, set the laser energy density to 1.0 J / cm2, the scanning spacing to 15 μm, the scanning speed to 50 mm / s, and repeat the processing 5 times to pattern the PI mask, wherein: the pattern unit size is 0.05 mm * 80 mm, the unit spacing is 0.15 mm, and the number of units is 100.

[0065] (5) Set the laser energy density to 0.3 J / cm2, the scanning interval to 5 μm and the scanning speed to 10 mm / s, and perform a second laser processing on the exposed edge 4 of the polyimide film to form a conductive graphene structure 5, wherein the scanning width is set to 20 μm.

[0066] (6) A 304 stainless steel sheet with a width of 0.3 mm is used as the tool electrode 6 and installed on the laser electrolysis platform. The metal workpiece 1 is connected to the positive terminal of the power supply, and the tool electrode 6 is connected to the negative terminal. Then, mask electrolysis is performed. During the processing, the laser beam movement path 8 is set as 100 short lines with a length of 0.05 mm, an interval of 0.15 mm, and a movement speed of 500 mm / s. The workpiece is driven by the motion platform to reciprocate along the direction perpendicular to the laser beam movement path 8. The movement speed is set to 0.1 mm / s, the reciprocating distance is 85 mm, and the number of reciprocations is 2.

[0067] (7) After the electrolytic processing is completed, the surface mask is removed, and then ultrasonic cleaning is performed with alcohol, deionized water, etc., and finally a large area microgroove structure is prepared on the surface of the aluminum sheet.

[0068] It should be noted that, Figure 3 Region A in the text refers to the area where the metal workpiece is exposed, as mentioned above. Example 2:

[0069] This embodiment is a further design based on Embodiment 1, and differs from Embodiment 1 only in the application features, namely:

[0070] like Figure 4 As shown, the mask electrolytic machining method provided in this embodiment can be used for machining hollow structures on metal workpieces. When used for machining hollow structures on metal workpieces, the reciprocating motion includes:

[0071] According to the preset laser beam motion path and speed, the workpiece is driven to rotate continuously around its own axis by a rotating platform at a speed of 5° / s. The tool electrode on the laser electrolysis platform is controlled to reciprocate along the axis of the metal workpiece until the electrolysis process forms a hollow pattern.

[0072] Regarding the mask electrolytic processing method disclosed in this application, such as Figure 5 As shown, more specifically:

[0073] (1) 316L stainless steel pipe with an outer diameter of 0.2 mm and a wall thickness of 0.1 mm is used as the metal workpiece (e.g. Figure 5 (a) The samples were ultrasonically cleaned for 5 minutes each with acetone, anhydrous ethanol and deionized water and then dried with cold air.

[0074] (2) Set the energy density of the ultraviolet nanosecond laser to 2~3 J / cm². 2 The scanning interval was 10 μm, the rotational linear velocity of the metal workpiece was 30 mm / s, and the cylindrical surface of the metal workpiece was subjected to nanotexturing treatment.

[0075] (3) A 0.02 mm thick polyimide (PI) film is prepared on the cylindrical surface of a metal workpiece by spraying, and then cured in a vacuum drying oven (e.g. Figure 5 (b) shown).

[0076] (4) Mount the metal workpiece on the laser electrolysis platform, and set the laser energy density to 2.0 J / cm² according to the properties of PI material. 2 The processing speed is 10mm / s, and the processing is repeated once. The PI mask is patterned, and the pattern shape is the same as the common vascular stent perforation pattern (e.g., Figure 5 (as shown in (c)).

[0077] (5) Set the laser energy density to 0.3 J / cm². 2 The processing speed is 10 mm / s, and the exposed edges of the polyimide film are subjected to a second laser processing to form a conductive graphene structure, wherein the scanning width is set to 10 μm (e.g., Figure 5 (d) shown.

[0078] (6) A 0.1 mm diameter tungsten wire is used as the tool electrode and mounted on the laser electrolysis platform. The metal workpiece is connected to the positive terminal of the power supply, and the tool electrode is connected to the negative terminal. Then, mask electrolysis is performed. During the processing, the metal workpiece rotates continuously around its own axis under the drive of the rotating platform at a speed of 5° / s. The tool electrode reciprocates continuously along the axis of the workpiece until the hollow pattern is formed (e.g., ...). Figure 5 (e) shown.

[0079] (7) Based on the actual needs of the vascular stent, the surface of the stent rib can be re-patterned using a mask to achieve the processing of drug storage holes or surface microtextures (e.g. Figure 5 (f) As shown, the process parameters can be referred to the relevant part of Example 1.

[0080] (8) After the electrolytic processing is completed, the surface mask (i.e., polyimide film) is removed, and then ultrasonic cleaning is performed with alcohol, deionized water, etc., and finally a metal vascular stent with drug reservoir / microstructure on the surface is prepared.

[0081] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A mask electrolytic processing method, wherein processing is performed using a laser electrolytic platform, the laser electrolytic platform having an integrated tool electrode connected to the negative terminal of a power supply, characterized in that... include: Obtain a metal workpiece with a polyimide film on its surface; The polyimide film is patterned according to the preset first laser direct writing process parameters to obtain an exposed metal workpiece, wherein the exposed area of ​​the metal workpiece corresponds to the patterned area. According to the preset second laser direct writing process parameters, the exposed edge of the polyimide film is subjected to secondary laser direct writing processing. Within the range that can induce graphene generation on the exposed edge of the polyimide film, a graphene structure connected to the metal workpiece is generated. Both the metal workpiece and the graphene structure are connected to the positive electrode of the power supply. The laser beam motion path of the laser electrolysis platform is set to be located in the area of ​​the exposed metal workpiece, and the laser beam motion path of the laser electrolysis platform is controlled to reciprocate in the area of ​​the exposed metal workpiece to complete the processing; The mask electrochemical machining method is used for microstructure machining of metal workpiece surfaces. When used for microstructure machining of metal workpiece surfaces, the reciprocating motion includes: Based on the preset laser beam motion path and speed, the workpiece is controlled by the motion platform to reciprocate along the horizontal direction. The mask electrolytic machining method is used for machining hollow structures on metal workpieces. When used for machining hollow structures on metal workpieces, the reciprocating motion includes: According to the preset laser beam motion path and speed, the workpiece is driven to rotate continuously around its own axis by the rotating platform, and the tool electrode on the laser electrolysis platform is controlled to reciprocate along the axis of the metal workpiece until the electrolysis process forms a hollow pattern.

2. The mask electrolytic processing method according to claim 1, characterized in that, Obtaining metal workpieces with a polyimide film on their surface includes: A polyimide solution is uniformly coated onto the surface of a metal workpiece, and then subjected to thermosetting treatment to obtain a polyimide film. The polyimide film is horizontally adhered to the surface of the metal workpiece using polyimide tape.

3. The mask electrolytic processing method according to claim 2, characterized in that, Before obtaining a metal workpiece with a polyimide film on its surface: The metal workpiece was ultrasonically cleaned and dried using acetone, anhydrous ethanol, and deionized water, respectively.

4. The mask electrolytic processing method according to claim 1, characterized in that, Also includes: Nanoscale structures are pre-fabricated on the surface of metal workpieces using laser processing.

5. The mask electrolytic processing method according to claim 1, characterized in that, Also includes: After electrolytic machining, the surface mask is removed, and the metal workpiece is ultrasonically cleaned using a disinfectant solution.

6. The mask electrolytic processing method according to claim 1, characterized in that, The first and second laser direct writing process parameters are both set based on the ablation threshold of the polyimide film.

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