Mask electrolytic machining method

Abstract

The invention discloses a mask electrolytic machining method in the technical field of mask machining. The method comprises the steps that a metal workpiece with a polyimide film prepared on the surface is obtained; carrying out patterning treatment on the polyimide film according to first laser direct writing processing technological parameters to obtain an exposed metal workpiece; performing secondary laser direct writing processing on the exposed edge of the polyimide film according to a second laser direct writing processing process parameter, and generating a graphene structure connected with the metal workpiece in a range capable of inducing graphene generation on the exposed edge of the polyimide film; and the laser beam motion path of the laser electrolysis platform is controlled to reciprocate in the exposed area of the metal workpiece, and machining is completed. According to the mask electrolytic machining method, the technical problems that due to the electric field concentration effect existing in an existing mask electrolytic machining technology, removal of materials in units is in an island shape, machining locality is reduced due to isotropic electrolytic corrosion, and consequently a microstructure with the large depth-to-width ratio is difficult to form can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of mask processing, and in particular to a mask electrolytic processing method. Background Art

[0002] Surface microtexturing technology utilizes micro-nanofabrication methods to create microstructure arrays with defined shapes and arrangements on a material's surface, thereby regulating its surface properties. Research has shown that surface microtexturing can effectively improve wettability, capillary forces, 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 methods for creating functional microtextures on metal surfaces include micro-milling, laser machining, electrical discharge machining (EDM), and masked electrochemical machining (MEM). Compared to other machining methods, masked electrochemical machining (MEM) offers significant advantages in terms of a lack of heat-affected zones (HAZs), no deterioration layers, and no burrs on the machined surface; unaffected by the mechanical properties of the material; and zero tool electrode wear.

[0004] In traditional mask electrochemical machining, due to the insulating properties of the mask material, the edges of the pattern cells inevitably produce an electric field concentration effect, resulting in "island-like" material removal within the cell. That is, the etched surface within the mask cell is high in the middle (slower etching) and low on the sides (electric field concentration, faster etching rate). In addition, the isotropic electrolytic etching reduces the localization of the processing, making it difficult to form microstructures with large aspect ratios.

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

[0006] The purpose of the present invention is to overcome the deficiencies in the prior art and to provide a mask electrolytic processing method, device and storage medium that can solve the technical problems existing in the existing mask electrolytic processing technology, such as the electric field concentration effect, which causes the removal of material within the unit to be in the shape of an "island", the isotropic electrolytic corrosion resulting in reduced processing localization, and the difficulty in forming microstructures with a large aspect ratio.

[0007] To achieve the above object, the present invention is implemented by adopting the following technical solutions: In a first aspect, the present invention provides a mask electrolytic processing method, which is processed by a laser electrolytic platform, wherein a tool electrode is integrated on the laser electrolytic platform, and the tool electrode is connected to the negative electrode of a power supply, comprising: obtaining a metal workpiece having a polyimide film prepared on the surface thereof; performing patterning on the polyimide film according to preset first laser direct writing process parameters to obtain a bare metal workpiece, wherein the exposed area of ​​the metal workpiece corresponds to the patterned area; performing a secondary laser direct writing process on the exposed edge of the polyimide film according to preset second laser direct writing process parameters, generating a graphene structure connected to the metal workpiece within a range capable of inducing graphene growth on the exposed edge of the polyimide film, wherein both the metal workpiece and the graphene structure are connected to a positive electrode of a power supply; The laser beam movement path of the laser electrolysis platform is set to be located in the exposed area of ​​the metal workpiece, and the laser beam movement path of the laser electrolysis platform is controlled to reciprocate in the exposed area of ​​the metal workpiece to complete the processing.

[0008] Furthermore, obtaining a metal workpiece with a polyimide film prepared on the surface includes: The polyimide solution is evenly coated on the surface of the metal workpiece, and then heat-cured to obtain a polyimide film; The polyimide film is horizontally adhered to the surface of the metal workpiece by using a polyimide tape.

[0009] Furthermore, before obtaining the metal workpiece with the polyimide film prepared on the surface: The metal workpiece is ultrasonically cleaned and dried using acetone, anhydrous ethanol and deionized water respectively.

[0010] Furthermore, it also includes: Laser processing is used in advance to prepare nanoscale structures on the surface of the metal workpiece.

[0011] Furthermore, it also includes: After the electrolytic machining is completed, the surface mask is removed and the metal workpiece is ultrasonically cleaned with a disinfectant.

[0012] Furthermore, the first laser direct writing process parameter and the second laser direct writing process parameter are both set based on the ablation threshold of the polyimide film.

[0013] Furthermore, when used for processing the microstructure of a metal workpiece surface, the reciprocating motion includes: According to the preset laser beam movement path and movement speed, the workpiece is controlled by the motion platform to reciprocate in the horizontal direction.

[0014] Furthermore, when used for hollow structure processing of metal workpieces, the reciprocating motion includes: According to the preset laser beam movement path and movement speed, the workpiece is driven to rotate continuously around its own axis through the rotating platform, and the tool electrode on the laser electrolysis platform is controlled to reciprocate along the axis direction of the metal workpiece until a hollow pattern is formed by electrolytic processing.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present invention proposes a mask electrolytic processing method. After obtaining a metal workpiece with a polyimide film prepared on the surface, the polyimide film is patterned according to a preset first laser direct writing processing parameter to obtain a bare metal workpiece. Then, the exposed edge of the polyimide film is subjected to a second laser direct writing processing according to a preset second laser direct writing processing parameter, thereby generating a graphene structure connected to the metal workpiece at the exposed edge of the polyimide film. The graphene structure is connected to the surface of the metal workpiece and can serve as a sacrificial anode during subsequent electrolytic processing, thereby improving the localization of the electrolytic processing and forming a microstructure with a large aspect ratio. By adjusting the second laser direct writing processing parameter, flexible in-situ preparation of sacrificial anodes of different widths, conductivity, and wettability can be achieved at the exposed edge of the polyimide film. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a flow chart of a mask electrolytic processing method provided in Example 1 of the present invention; 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 Example 1 of the present invention; Figure 3 This is a schematic diagram of the process from the fourth step to the fifth step in a mask electrolytic processing method provided in Example 1 of the present invention; Figure 4 This is a schematic diagram of hollowing processing in a mask electrolytic processing method provided in the second embodiment of the present invention; Figure 5 This is a schematic diagram of a specific process in a mask electrolytic processing method provided in the second embodiment of the present invention; 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 movement path. DETAILED DESCRIPTION

[0017] The technical solution of the present invention is described in detail below through the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present application and the specific features in the embodiments are detailed descriptions of the technical solution of the present application, rather than limitations on the technical solution of the present application. Unless there is a conflict, the embodiments of the present application and the technical features in the embodiments can be combined with each other.

[0018] As used herein, the term "and / or" simply describes a relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A alone, A and B, or B alone. Furthermore, the character " / " generally indicates an "or" relationship between the associated objects.

[0019] The mask electrolysis processing method mentioned in the specific implementation method part of this application is processed by a laser electrolysis platform. The laser electrolysis platform belongs to the existing technology and will not be described in detail here. The specific real-time method disclosed in this application only plays the role of laser electrolysis processing. The laser electrolysis platform is integrated with a tool electrode 6, and the tool electrode 6 is connected to the negative pole of the power supply.

[0020] Specifically, in the present application, a metal foil such as stainless steel with a certain width can be used as the tool electrode 6, and laser processing can be used to in-situ process a narrow slit 7 on the tool electrode 6 to increase the subsequent laser transmission.

[0021] For ease of understanding, some of the terms mentioned in this application are explained: Polyimide (PI) is a type of high-performance polymer material, 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.

[0022] The ablation threshold of PI material (polyimide) refers to the critical energy density at which significant ablation (material removal) begins to occur under the action of high-energy laser or plasma. Embodiment 1:

[0023] Figure 1 This is a flow chart of the mask electrolytic processing method in the first embodiment of the present invention. This flow chart only shows the logical sequence of the method described in this embodiment. In other possible embodiments of the present invention, different methods may be used without conflict. Figure 1 The steps shown or described are accomplished in the order shown.

[0024] 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. The device can be implemented by software and / or hardware, and the device can be integrated into a terminal, such as any smartphone, tablet computer, or computer device with communication capabilities. The method of this embodiment specifically includes the following steps: Step 1: Obtain a metal workpiece 1 having a polyimide film prepared on its surface: The polyimide solution is evenly coated on the surface of the metal workpiece 1 by spin coating, spray coating, etc., and then subjected to heat curing treatment to obtain a polyimide film 2; The polyimide film 2 is horizontally adhered to the surface of the metal workpiece 1 by a polyimide tape using a laminating instrument or other equipment to obtain the metal workpiece 1 with the polyimide film 2 prepared on the surface.

[0025] In addition, before obtaining the metal workpiece 1 with the polyimide film 2 prepared on the surface, the metal workpiece 1 can be ultrasonically cleaned and dried using acetone, anhydrous ethanol and deionized water respectively.

[0026] In addition, before obtaining the metal workpiece 1 with the polyimide film 2 prepared on the surface, laser processing can be used to prepare a nano-scale structure on the surface of the metal workpiece 1 in advance. By increasing the contact area of ​​the film / metal workpiece 1 and utilizing the surface effect of the nanostructure, the interface 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.

[0027] Step 2: Patterning the polyimide film 2 according to preset first laser direct writing process parameters to obtain a bare metal workpiece 1, wherein the exposed area of ​​the metal workpiece 1 corresponds to the patterned area, i.e., the polyimide film pattern unit 3; Step 3: performing a secondary laser direct writing process on the exposed edge 4 of the polyimide film according to preset second laser direct writing process parameters, generating a graphene structure 5 connected to the metal workpiece 1 within a range capable of inducing graphene generation on the exposed edge 4 of the polyimide film, wherein both the metal workpiece 1 and the graphene structure 5 are connected to the positive electrode of a power supply; 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 during the subsequent electrolytic machining process, thereby improving the localization of the electrolytic machining and forming a microstructure with a large aspect ratio; Among them, the 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 the electrolyte to allow the anode metal, as the "sacrificial" metal, to corrode first, thereby protecting the protected metal (cathode) from damage.

[0028] It should be noted that both the processing of the polyimide film pattern unit 3 and the processing of the sacrificial anode on its edge are completed in the same processing system, without the need for secondary clamping. It is only necessary to change the processing path in the system to complete it, which can avoid the occurrence of positioning errors and improve accuracy.

[0029] 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.

[0030] It should be noted that the first laser direct writing processing parameters and the second laser direct writing processing parameters mentioned in this application can be adjusted according to actual application needs.

[0031] After the electrolytic processing is completed, the surface mask is removed, and the metal workpiece 1 is ultrasonically cleaned with a disinfectant such as alcohol, deionized water, or the like.

[0032] It should be noted that the first laser direct writing process parameter and the second laser direct writing process parameter are both set based on the ablation threshold of the polyimide film.

[0033] The mask electrolytic machining method provided in this embodiment can be used for machining the surface microstructure of a metal workpiece 1. When used for machining the surface microstructure of a metal workpiece 1, the reciprocating motion includes: According to the preset laser beam movement path 8 and movement speed, the metal workpiece 1 is controlled by the movement platform to perform reciprocating movement in the horizontal direction.

[0034] Regarding the mask electrolytic processing method disclosed in this application, more specifically, Figure 2 and Figure 3 As shown: (1) A 0.2 mm thick aluminum sheet was used as the metal workpiece 1, and ultrasonically cleaned with acetone, anhydrous ethanol, and deionized water for 5 minutes respectively, and then dried with cold air.

[0035] (2) The energy density of the ultraviolet nanosecond laser is set to 2~3J / cm2, the scanning interval is 10μm, and the scanning speed is 30mm / s to perform nanotexturing on the surface of the metal workpiece 1, thereby improving the bonding strength between the subsequent mask and the substrate.

[0036] (3) A 0.035 mm thick polyimide tape is used as a masking material and is horizontally attached to the surface of the metal workpiece 1 using a laminating machine.

[0037] (4) The metal workpiece 1 is mounted on the laser electrolysis platform. According to the properties of the PI material, the laser energy density is set to 1.0 J / cm2, the scanning pitch is 15 μm, the scanning speed is 50 mm / s, and the processing is repeated 5 times. The PI mask is patterned, where the pattern unit size is 0.05 mm*80 mm, the unit spacing is 0.15 mm, and the number of units is 100.

[0038] (5) Setting the laser energy density to 0.3 J / cm2, the scanning interval to 5 μm, and the scanning speed to 10 mm / s, the exposed edge 4 of the polyimide film was laser processed for the second time to form a conductive graphene structure 5, wherein the scanning width was set to 20 μm.

[0039] (6) A 304 stainless steel sheet with a width of 0.3 mm was used as the tool electrode 6 and mounted on the laser electrolysis platform. The metal workpiece 1 was connected to the positive electrode of the power supply and the tool electrode 6 was connected to the negative electrode, and then the mask electrolysis process was performed. During the processing, the laser beam motion path 8 was set to a short line with a length of 0.05 mm, an interval of 0.15 mm, and a number of 100 short lines. The motion speed was 500 mm / s, and the workpiece was driven by the motion platform to reciprocate in a direction perpendicular to the laser beam motion path 8. The motion speed was set to 0.1 mm / s, the reciprocating distance was 85 mm, and the number of reciprocating times was 2.

[0040] (7) After the electrolytic processing is completed, the surface mask is removed, and then ultrasonic cleaning is performed using alcohol, deionized water, etc., and finally a large-area micro-groove structure is prepared on the surface of the aluminum sheet.

[0041] It should be noted that Figure 3 The area A in the figure is the exposed area of ​​the metal workpiece mentioned above. Example 2:

[0042] This embodiment is further designed based on the first embodiment, and differs from the first embodiment only in the usage characteristics, namely: like Figure 4 As shown, the mask electrolytic processing method provided in this embodiment can be used for processing the hollow structure of a metal workpiece. When used for processing the hollow structure of a metal workpiece, the reciprocating motion includes: According to the preset laser beam movement path and movement speed, the workpiece is driven to rotate continuously around its own axis through the rotating platform at a speed of 5° / s, and the tool electrode on the laser electrolysis platform is controlled to reciprocate along the axis direction of the metal workpiece until a hollow pattern is formed by electrolytic processing.

[0043] Regarding the mask electrolytic processing method disclosed in this application, Figure 5 As shown, more specifically: (1) Use 316L stainless steel pipe with an outer diameter of 0.2mm and a wall thickness of 0.1mm as the metal workpiece (such as Figure 5 (a), ultrasonically cleaned with acetone, anhydrous ethanol and deionized water for 5 minutes respectively and dried with cold air.

[0044] (2) Set the UV nanosecond laser energy density to 2~3J / cm 2, the scanning interval is 10 μm, the rotation linear speed of the metal workpiece is 30 mm / s, and the cylindrical surface of the metal workpiece is nano-textured.

[0045] (3) A polyimide (PI) film with a thickness of 0.02 mm was prepared on the cylindrical surface of the metal workpiece by spraying, and then cured in a vacuum drying oven (e.g. Figure 5 (b)

[0046] (4) The metal workpiece is mounted on the laser electrolysis platform. According to the properties of PI material, the laser energy density is set to 2.0 J / cm 2 The processing speed is 10 mm / s, and the processing is repeated once. The PI mask is patterned, wherein: the pattern shape is the same as the common vascular stent hollow pattern (such as Figure 5 (c)

[0047] (5) Set the laser energy density to 0.3 J / cm 2 , processing speed 10mm / s, the exposed edge of the polyimide film is laser processed for the second time to form a conductive graphene structure, wherein: the scanning width is set to 10μm (such as Figure 5 (d)

[0048] (6) A tungsten wire with a diameter of 0.1 mm is used as the tool electrode and mounted on the laser electrolysis platform. The metal workpiece is connected to the positive electrode of the power supply and the tool electrode is connected to the negative electrode, and then the mask electrolysis is performed. During the processing, the metal workpiece is driven by the rotating platform to continuously rotate around its own axis at a speed of 5° / s. The tool electrode continuously reciprocates along the axis of the workpiece, and the electrolysis process stops until a hollow pattern is formed (such as Figure 5 (e)).

[0049] (7) According to the actual needs of the vascular stent, the mask patterning process can be performed again on the surface of the stent rib to realize the processing of drug storage holes or surface micro-texture (such as Figure 5 (f), the process parameters can refer to the relevant part of Example 1).

[0050] (8) After the electrolytic processing is completed, the surface mask (i.e., polyimide film) is removed, and then ultrasonic cleaning is performed using alcohol, deionized water, etc., and finally a metal vascular stent with a drug reservoir / microtexture on the surface is prepared.

[0051] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A mask electrolytic processing method, which is processed by a laser electrolytic platform, wherein a tool electrode is integrated on the laser electrolytic platform, and the tool electrode is connected to the negative electrode of the power supply, characterized in that: include: obtaining a metal workpiece having a polyimide film prepared on the surface thereof; performing patterning on the polyimide film according to preset first laser direct writing process parameters to obtain a bare metal workpiece, wherein the exposed area of ​​the metal workpiece corresponds to the patterned area; performing a secondary laser direct writing process on the exposed edge of the polyimide film according to preset second laser direct writing process parameters, generating a graphene structure connected to the metal workpiece within a range capable of inducing graphene growth on the exposed edge of the polyimide film, wherein both the metal workpiece and the graphene structure are connected to a positive electrode of a power supply; The laser beam movement path of the laser electrolysis platform is set to be located in the exposed area of ​​the metal workpiece, and the laser beam movement path of the laser electrolysis platform is controlled to reciprocate in the exposed area of ​​the metal workpiece to complete the processing.

2. The mask electrolytic processing method according to claim 1, characterized in that: The method for obtaining a metal workpiece having a polyimide film prepared on its surface comprises: The polyimide solution is evenly coated on the surface of the metal workpiece, and then heat-cured to obtain a polyimide film; The polyimide film is horizontally adhered to the surface of the metal workpiece by using a polyimide tape.

3. The mask electrolytic processing method according to claim 2, characterized in that: Before obtaining a metal workpiece with a polyimide film prepared on its surface: The metal workpiece is 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: Laser processing is used in advance to prepare nanoscale structures on the surface of the metal workpiece.

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

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

7. The mask electrochemical processing method according to claim 1, characterized in that: Used for processing the microstructure of a metal workpiece surface. When used for processing the microstructure of a metal workpiece surface, the reciprocating motion includes: According to the preset laser beam movement path and movement speed, the workpiece is controlled by the motion platform to reciprocate in the horizontal direction.

8. The mask electrochemical processing method according to claim 1, characterized in that: Used for hollow structure processing of metal workpieces. When used for hollow structure processing of metal workpieces, the reciprocating motion includes: According to the preset laser beam movement path and movement speed, the workpiece is driven to rotate continuously around its own axis through the rotating platform, and the tool electrode on the laser electrolysis platform is controlled to reciprocate along the axis direction of the metal workpiece until a hollow pattern is formed by electrolytic processing.

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