Template type spark assisted chemical etching processing method and device

Abstract

The application relates to the technical field of precision machining, and provides a template type spark-assisted chemical etching machining method and device, which comprises a reaction tank, a template assembly, a fixing piece and an auxiliary electrode, the template assembly comprises a template tool electrode and an insulating template, and the auxiliary electrode is used for forming an electric field with the template tool electrode. A first array of hollow structures is formed on the template tool electrode, and a second array of hollow structures corresponding to the positions of the first array of hollow structures is formed on the insulating template. Thus, in the case that an electrolyte is contained in a containing cavity of the reaction tank, the workpiece surface is partially exposed to the electrolyte through the first array of hollow structures and the second array of hollow structures, thereby, the spark discharge plasma can be induced at the first array of hollow structures at one time, and the microstructure can be formed on the exposed position of the workpiece surface, the discrete and multi-point array spark discharge plasma can be induced at one time, the array microstructure can be machined, and the method has the advantages of good machining convenience and high machining efficiency.

Description

Technical Field

[0001] This invention relates to the field of precision machining technology, and in particular to a template-type spark-assisted chemical etching method and apparatus. Background Technology

[0002] Currently, the main methods for processing workpiece surfaces include mechanical cutting, hot pressing, water jet processing, laser processing, and ultrasonic processing. However, these processing methods are difficult to meet the needs of processing micro-array structures on workpiece surfaces, and have problems such as high processing difficulty, low efficiency, and poor surface quality. Summary of the Invention

[0003] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes a template-type spark-assisted chemical etching (SED) apparatus, which can achieve high-efficiency machining of microarray structures on the workpiece surface. This invention also proposes a machining method using this template-type SED apparatus.

[0004] A template-type spark-assisted chemical etching apparatus according to a first aspect embodiment of the present invention includes a reaction tank, a template assembly, a fixture, and an auxiliary electrode, wherein:

[0005] The reaction vessel has a accommodating cavity for holding the electrolyte;

[0006] The template assembly includes a template tool electrode and an insulating template stacked together. A first array of hollow structures is formed on the template tool electrode, and a second array of hollow structures corresponding to the positions of the first array of hollow structures are formed on the insulating template.

[0007] A fastener is provided for detachably mounting the template assembly and the workpiece to be processed within the accommodating cavity. The fastener is used to mount the workpiece on the side of the template tool electrode facing away from the insulating template.

[0008] An auxiliary electrode is disposed within the accommodating cavity and is used to form an electric field with the template tool electrode.

[0009] The template-type spark-assisted chemical etching apparatus of this invention has at least the following advantages: In application, a template assembly is stacked on the surface of the workpiece, and a template tool electrode is attached to the surface of the workpiece. The assembly is installed in a receiving cavity by a fixing component. Electrolyte is added to the receiving cavity. The surface of the workpiece is partially covered by the template tool electrode and the insulating template, and partially exposed to the electrolyte through the first array hollow structure and the second array hollow structure. The template tool electrode and the auxiliary electrode are connected to a power source to form an electric field to achieve the processing conditions for chemical etching. The template tool electrode induces spark discharge plasma at the first array hollow structure in one go, and microstructures are formed at the exposed position on the workpiece surface. This achieves the one-time processing of an array microstructure consistent with the first array hollow structure. It has the advantages of good processing convenience and high processing efficiency. The array microstructure formed by the processing is determined by the first array hollow structure, which has good controllability. High-quality processed surfaces are achieved by processing based on chemical etching.

[0010] According to some embodiments of the template-type spark-assisted chemical etching apparatus of the present invention, the fixing member includes a frame and a limiting step, wherein:

[0011] The frame encloses to form an installation cavity, which is used to accommodate the template assembly and the workpiece. The frame is detachably connected to the reaction tank so that the workpiece, template tool electrode, and insulating template are sequentially stacked and fixed in the accommodating cavity.

[0012] The limiting step protrudes inward from the inner wall of the frame to abut against the side of the insulating template away from the template tool electrode. An opening is formed between the limiting steps to communicate with the mounting cavity, so that a part of the workpiece surface is exposed to the receiving cavity through the first array hollow structure, the second array hollow structure and the opening.

[0013] According to some embodiments of the present invention, in a template-type spark-assisted chemical etching apparatus, a wire hole is formed on the frame, the wire hole communicating with the mounting cavity for introducing a wire to connect to the template tool electrode.

[0014] According to some embodiments of the present invention, in a template-type spark-assisted chemical etching apparatus, the first array hollow structure and the second array hollow structure have the same size.

[0015] According to some embodiments of the present invention, in a template-type spark-assisted chemical etching apparatus, the reaction tank includes a bottom wall and a side wall that enclose the accommodating cavity, the auxiliary electrode is fixed to the inner wall of the side wall, and the fixing member is mounted on the bottom wall.

[0016] According to some embodiments of the present invention, the template-type spark-assisted chemical etching apparatus has a template tool electrode thickness of 0.1 mm to 1 mm; and / or, the insulating template has a thickness of 0.1 mm to 1 mm.

[0017] According to some embodiments of the present invention, a template-type spark-assisted chemical etching apparatus further includes a power supply, wherein the auxiliary electrode is electrically connected to the positive terminal of the power supply, and the template tool electrode is electrically connected to the negative terminal of the power supply.

[0018] A template-based spark-assisted chemical etching method using the template-based spark-assisted chemical etching apparatus of the above embodiments, according to a second aspect of the present invention, includes sequentially stacking a template tool electrode and an insulating template on the surface of a workpiece, connecting the template tool electrode and an auxiliary electrode to a power source to form an electric field, in an electrolyte, inducing spark discharge plasma through the template tool electrode at a first array hollow structure, forming local spark-assisted chemical etching at a position on the workpiece surface corresponding to the first array hollow structure, and after etching is completed, forming an array microstructure on the workpiece surface corresponding to the first array hollow structure.

[0019] The template-type spark-assisted chemical etching apparatus of this invention has at least the following beneficial effects: the template tool electrode and the auxiliary electrode are connected to the power supply to form an electric field to achieve the processing conditions for chemical etching, and the template tool electrode is used to induce spark discharge plasma at the first array hollow structure in one go to realize spark-assisted chemical etching, thereby forming microstructures at the exposed position on the workpiece surface, realizing the one-time processing of array microstructures consistent with the first array hollow structure, which has the advantages of good processing convenience and high processing efficiency, and achieving high-quality processed surface based on chemical etching.

[0020] According to some embodiments of the present invention, the template-type spark-assisted chemical etching method uses a power supply output pulse waveform to perform processing during the pulse phase and to renew the electrolyte during the inter-pulse phase.

[0021] According to some embodiments of the present invention, the template-type spark-assisted chemical etching method changes the microstructure formed on the workpiece surface by replacing the template tool electrode with a different first array hollow structure and the insulating template with a corresponding and consistent second array hollow structure.

[0022] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0024] Figure 1 This is a schematic diagram of a template-type spark-assisted chemical etching apparatus according to one embodiment.

[0025] Figure 2 for Figure 1 The enlarged schematic diagram at point A in the diagram shows the corresponding positions of the first and second array hollow structures.

[0026] Figure 3 This is an exploded view of the insulating template-template tool electrode-workpiece stack structure;

[0027] Figure 4 A schematic diagram showing the formation of a gas film at the first array cutout when using a template-type spark-assisted chemical etching (SED) apparatus.

[0028] Figure 5 A schematic diagram showing the formation of spark discharge plasma at the first array cutout when using a template-type spark-assisted chemical etching (SALDI) apparatus.

[0029] Figure 6 A schematic diagram illustrating the formation of pits on the workpiece surface during the application of a template-type spark-assisted chemical etching (SED) apparatus.

[0030] Figure 7 A schematic diagram illustrating the formation of a central pit on the workpiece surface during the application of a template-type spark-assisted chemical etching (SED) apparatus.

[0031] Figure 8 This is a schematic diagram of the structure of the fastener in one embodiment;

[0032] Figure 9 for Figure 8 A structural schematic diagram of the fastener from another perspective;

[0033] Figure 10 This is a schematic diagram of the voltage-current waveform during the formation of spark discharge plasma.

[0034] Figure 11 This is a schematic diagram of the processing procedure using pulse waveform-controlled template-type spark-assisted chemical etching in one embodiment.

[0035] Figure label:

[0036] Reaction tank 100; containment cavity 101; electrolyte 102;

[0037] Template tool electrode 200; First array hollow structure 201; Gas film 202; Plasma 203; Bubble 204;

[0038] Insulating template 300; Second array hollow structure 301;

[0039] Fastener 400; Frame 401; Limiting step 402; Mounting cavity 403; Wire hole 404; Opening 405;

[0040] Auxiliary electrode 500;

[0041] Power supply 600;

[0042] Workpiece 700; recessed structure 701; central recess 702. Detailed Implementation

[0043] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0044] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0045] In the description of this invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0046] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0047] In the description of this invention, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0048] This invention proposes a template-based spark-assisted chemical etching (SALDI) apparatus and method. By utilizing spark discharge plasma energy through a template tool electrode, it promotes high-temperature chemical etching of the workpiece material, forming an array of microstructures on the surface of a glass workpiece in a single process. This achieves high-efficiency, high-quality, and high-stability processing of the array of microstructures on the workpiece surface. The embodiments of this application are described below with reference to the accompanying drawings:

[0049] refer to Figures 1 to 3 The first aspect of the present invention provides a template-type spark-assisted chemical etching apparatus, including a reaction tank 100, a template assembly, a fixture 400 and an auxiliary electrode 500.

[0050] The reaction tank 100 has a receiving cavity 101 for containing the electrolyte 102. The template assembly includes a template tool electrode 200 and an insulating template 300 stacked together. A fixing member 400 detachably mounts the template assembly and the workpiece 700 to be processed into the receiving cavity 101. The fixing member 400 is used to mount the workpiece 700 on the side of the template tool electrode 200 away from the insulating template 300. An auxiliary electrode 500 is disposed in the receiving cavity 101 to form an electric field with the template tool electrode 200. In application, the template assembly is stacked on the surface of the workpiece 700, the template tool electrode 200 is attached to the surface of the workpiece 700, and the fixing member 400 is used to mount it into the receiving cavity 101.

[0051] The template tool electrode 200 has a first array of hollow structures 201 formed on it, and the insulating template 300 has a second array of hollow structures 301 corresponding to the position of the first array of hollow structures 201. Thus, when the accommodating cavity 101 of the reaction tank 100 is filled with electrolyte 102, the surface of the workpiece 700 is partially covered by the template tool electrode 200 and the insulating template 300, and partially exposed to the electrolyte 102 through the first array of hollow structures 201 and the second array of hollow structures 301. The template tool electrode 200 and the auxiliary electrode 500 are connected to the power supply 600 to form an electric field to achieve the processing conditions for chemical etching. Therefore, by using the template tool electrode 200 to induce spark discharge plasma at the first array hollow structure 201 in a single operation, microstructures are formed at the exposed positions on the surface of the workpiece 700. This achieves one-time induction of discrete, multi-point array spark discharge plasma, producing an array microstructure consistent with the first array hollow structure 201. This method offers advantages such as ease of processing and high processing efficiency. The resulting array microstructure is determined by the first array hollow structure 201, ensuring good controllability. Based on the principle of thermally promoted chemical etching, the processed surface is free of burrs, cracks, and thermally altered layers, enabling the fabrication of high-quality array microstructures.

[0052] refer to Figure 1In some embodiments of the template-type spark-assisted chemical etching apparatus, the reaction tank 100 includes a bottom wall and side walls that enclose and form a receiving cavity 101. A fixing member 400 is mounted on the bottom wall, thereby fixing the workpiece 700, the template tool electrode 200, and the insulating template 300 to the bottom wall. In use, electrolyte 102 is added to the receiving cavity so that the liquid level is at least higher than the fixing member 400. An auxiliary electrode 500 is fixed to the inner wall of the side wall and can contact the electrolyte 102 in the receiving cavity 101. Thus, by connecting the auxiliary electrode 500 and the template tool electrode 200 to a power supply 600, ions in the electrolyte solution begin to move, forming a current. In some embodiments, the auxiliary electrode 500 is embedded in the inner wall of the side wall of the reaction tank 100, and can cover part or all of the surface of the inner wall. Figure 1 In the illustrated embodiment, the reaction tank 100 adopts a square structure, with auxiliary electrodes 500 provided on the inner walls of all four side walls, surrounding the template tool electrode 200 and the workpiece 700. This creates a uniform electric field, facilitates contact with the electrolyte 102, and allows for easy connection to the power supply 600. The auxiliary electrodes 500 can be made of graphite or an inert metal, such as platinum. The template tool electrode 200 can be made of conventional metals, such as copper, stainless steel, or tungsten carbide.

[0053] refer to Figure 1 In some embodiments, the template-type spark-assisted chemical etching apparatus further includes a power supply 600, an auxiliary electrode 500 electrically connected to the positive terminal of the power supply 600, and a template tool electrode 200 electrically connected to the negative terminal of the power supply 600, thereby forming an electric field through the flow of ions and electrons in the electrolyte, enabling the electrochemical reaction to proceed continuously.

[0054] refer to Figures 4 to 6 The diagram illustrates the processing of one location of the first array hollow structure 201, where an oxidation reaction occurs on the surface of the auxiliary electrode 500, and the reaction equation is as follows:

[0055] 4OH - -4e - →2H₂O + O₂↑

[0056] A reduction reaction occurs on the surface of the template tool electrode 200. The reaction equation is as follows:

[0057] 2H2O+2e - →H₂↑+2OH -

[0058] Due to the applied high voltage, the first array perforated area of ​​the template tool electrode 200 is rapidly surrounded by hydrogen bubbles 204, causing a rapid increase in resistance between the two electrodes, thereby generating a large amount of Joule heat, and further forming a water vapor film 202 around the first array perforated area (e.g., Figure 4The current flow is blocked. When the electric field strength between the two electrodes reaches a set value (e.g., 10), the current flow is blocked. 6 V·cm -1 When the above conditions are met, spark discharge plasma 203 is induced at the hollowed-out area (e.g., Figure 5 This creates a localized, small-scale spark-assisted chemical etching process, fabricating a micro-pit structure 701 on the surface of workpiece 700 (e.g., ...). Figure 6 ).

[0059] Understandably, the corrosion rate of alkaline solutions at room temperature is extremely low. By inducing plasma generation at the perforated holes of the first array perforated structure 201 of the template tool electrode 200, the heat energy generated by the discharge raises the temperature of the processing area (generally reaching over 600°C). Thus, the plasma induced by high voltage increases the temperature of the processing area, thereby effectively promoting the chemical etching rate and improving processing efficiency.

[0060] refer to Figure 2 and Figure 3 The first array of perforated structures 201 is formed by multiple perforated holes. The perforated holes shown in the illustration are circular and are only provided as a feasible example. The shape, size, arrangement pattern, and range of the perforated holes can be set according to the pattern to be etched on the surface of the workpiece 700. The size of the second array of perforated structures 301 is the same as that of the first array of perforated structures 201. That is to say, the second array of perforated structures 301 is also formed by multiple perforated holes, and the shape, size, arrangement pattern, and range of the perforated holes in the second array of perforated structures 301 are consistent with those in the first array of perforated structures 201, and they correspond one-to-one. Thus, the insulating template 300, the template tool electrode 200, and the workpiece 700 are tightly stacked together. The insulating template 300 covers the surface of the template tool electrode 200, and only a small area of ​​the template tool electrode 200 with perforations is exposed to the electrolyte 102, thereby concentrating the current flow.

[0061] In some embodiments, the thickness of the template tool electrode 200 is 0.1 mm to 1 mm, for example, it can be 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, or any other value within the range of 0.1 mm to 1 mm. At this thickness, the template tool electrode 200 forms a water vapor film around the hollowed-out hole, which can effectively block the current flow. When the electric field strength reaches a preset value, it can also successfully form a spark discharge plasma to break down and process the surface of the workpiece 700 to form a pit structure.

[0062] In some embodiments, the thickness of the insulating template 300 can be equal to the thickness of the template tool electrode 200 for ease of processing, or it can be slightly different. The thickness of the insulating template 300 is 0.1 mm to 1 mm, for example, it can be 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, or any other value within the range of 0.1 mm to 1 mm.

[0063] refer to Figure 7 By changing the size of the perforations in the template tool electrode 200 and the insulating template 300, the morphology of the pits formed on the surface of the workpiece 700 can be altered. For example, by reducing the size of the perforations in the insulating template 300 and the template tool electrode 200, the area of ​​the workpiece 700 surface exposed to the electrolyte 102 through the perforations is reduced. The pit structure formed at the edge of the perforations in the template tool electrode 200 moves closer to the center, resulting in a central pit 702 structure. The shape, size, arrangement, and range of the perforations in the template tool electrode 200 and the insulating template 300 can be used to control the etching of shapes / patterns / processing areas on the surface of the workpiece 700, offering good controllability and high dimensional stability. The large-area array of perforations on the insulating template 300 and the template tool electrode 200 enables discrete multi-point spark-assisted chemical etching.

[0064] refer to Figure 8 and Figure 9 The fastener 400 may include a frame 401 and a limiting step 402. The frame 401 encloses to form a mounting cavity 403, which is used to accommodate the template assembly and the workpiece 700. The frame 401 is detachably connected to the reaction tank 100 to sequentially stack and fix the workpiece 700, the template tool electrode 200, and the insulating template 300 in the accommodating cavity 101.

[0065] A wire hole 404 can be formed on the frame 401, which connects to the mounting cavity 403 for introducing wires to connect to the template tool electrode 200, making the connection convenient and easy to implement. A limiting step 402 protrudes inward from the inner wall of the frame 401 to abut against the side of the insulating template 300 away from the template tool electrode 200, keeping the workpiece 700, template tool electrode 200, and insulating template 300 in close contact. An opening 405 connecting to the mounting cavity 403 is formed between the limiting steps 402, allowing a portion of the workpiece 700's surface to be exposed to the receiving cavity 101 via the first array of perforated structures 201, the second array of perforated structures 301, and the opening 405, thereby contacting the electrolyte 102 in the receiving cavity 101.

[0066] In use, the workpiece 700 to be processed, the template tool electrode 200, and the insulating template 300 can be stacked sequentially from bottom to top in the receiving cavity 101 of the reaction tank 100 and placed on the bottom wall. The fixing member 400 is surrounded by the stacked structure of the workpiece 700, template tool electrode 200, and insulating template 300 through the frame 401, so that the three are housed in the mounting cavity 403. The frame 401 is installed on the bottom wall of the reaction tank 100. The limiting step 402 abuts against the upper surface of the insulating template 300, so that the insulating template 300 abuts against the template tool electrode 200 downwards, and thus the template tool electrode 200 is pressed against the surface of the workpiece 700 downwards. This enables the heat generated by the spark discharge to be quickly conducted to the surface of the workpiece 700, and the pattern of the first array hollow structure 201 of the template tool electrode 200 is directly copied onto the surface of the workpiece 700.

[0067] refer to Figure 10 The voltage-current waveforms during the spark discharge plasma formation process are shown. The power supply 600 can output constant DC waveforms, pulse waveforms, square waves, triangular waves, sine waves, and sawtooth waves. This embodiment uses a pulsed DC voltage as an example. Figure 10 When a voltage is applied, the current instantaneously reaches its maximum value (approximately 2-6A). Immediately afterwards, the formation of a gas film 202 on the surface of the perforated area of ​​the template tool electrode 200 hinders current flow, causing the current to rapidly decrease and eventually stabilize at a plasma current of around 100mA. In practical applications, pulsed current, constant voltage, or constant current waveforms are equally applicable.

[0068] A second aspect of the present invention provides a template-based spark-assisted chemical etching (SALDI) method, which uses the template-based SALDI apparatus described in the above embodiments. The apparatus structure can be referred to in the preceding embodiments and their accompanying drawings. The method includes: sequentially stacking a template tool electrode 200 and an insulating template 300 on the surface of a workpiece 700; connecting the template tool electrode 200 and an auxiliary electrode 500 to a power supply 600 to form an electric field; in an electrolyte 102, inducing spark discharge plasma through the template tool electrode 200 at the first array hollow structure 201; forming localized spark-assisted chemical etching on the surface of the workpiece 700 at the position corresponding to the first array hollow structure 201; and after etching, forming an array microstructure corresponding to the first array hollow structure 201 on the surface of the workpiece 700.

[0069] In the electrolyte 102 environment, by connecting the template tool electrode 200 and the auxiliary electrode 500 to the power supply 600 to form an electric field, the processing conditions for chemical etching are achieved. The template tool electrode 200 is used to induce spark discharge plasma at the first array hollow structure 201 in one go to achieve spark-assisted chemical etching. This process forms microstructures at the exposed positions on the surface of the workpiece 700, realizing discrete multi-point spark-assisted chemical etching. This process produces an array microstructure consistent with the first array hollow structure 201 in one go. It has the advantages of good processing convenience and high processing efficiency. The processing shape / pattern is determined by the shape / pattern of the first array hollow structure 201, which has good controllability. The high-quality processing surface is achieved by processing based on chemical etching.

[0070] In some embodiments of the template-based spark-assisted chemical etching method, a power supply 600 outputs a pulse waveform, as referenced. Figure 11 This illustrates a pulse waveform-controlled template-based spark-assisted chemical etching (SALDI) process. Due to the applied high voltage, in process (a), the pulse rise time, the cutouts in the template tool electrode 200 are rapidly surrounded by hydrogen bubbles 204, causing a rapid increase in resistance between the two electrodes and generating significant Joule heating. This further forms a water vapor film 202 around the metal electrodes, blocking current flow. In process (b), the pulse duration, the electric field strength between the two electrodes reaches a set value, forming spark discharge plasma and machining pits on the workpiece 700 surface. In process (c), the inter-pulse duration, hydrogen bubbles 204 are formed at the cutouts in the template tool electrode 200. Therefore, the entire machining process can be controlled by the pulse waveform output from the power supply 600. Machining can be performed during the pulse phase, while the electrolyte 102 is renewed and circulated during the inter-pulse phase, ensuring overall machining stability.

[0071] In some embodiments of the template-based spark-assisted chemical etching (SIE) method, the microstructure formed on the surface of the workpiece 700 is altered by replacing the template tool electrode 200 with different first array perforated structures 201 and the insulating template 300 with corresponding and consistent second array perforated structures 301. For example, by replacing the template tool electrode 200 and the insulating template 300 with different perforated hole shapes, sizes, arrangement patterns, or arrangement ranges, the shape / pattern / processing area etched on the surface of the workpiece 700 can be controlled, resulting in good controllability and high dimensional stability of the processing.

[0072] This invention relates to a template-based spark-assisted chemical etching (SIE) apparatus and method, applicable to the fabrication of array microstructures on the surface of glass workpieces. Fabricating surface array microstructures with specific textures and periodicity on the glass workpiece surface enables glass devices to exhibit new functions. The effects of these new functions can be adjusted by changing their size and shape, or by altering the arrangement of the microstructures. For example, fabricating an array of micro-pit structures on the glass surface is a crucial step in preparing microlens arrays. By changing the size and curvature of the aperture, not only can the basic functions of traditional lenses, such as focusing and imaging, be altered, but the resulting microlens array also features small unit size and high integration, providing favorable conditions for constructing many novel optical systems.

[0073] Understandably, current glass processing methods mainly include mechanical cutting, hot pressing, ultrasonic processing, laser processing, waterjet processing, and spark-assisted chemical etching. These methods present numerous challenges and problems when used to process microstructures on the surface of glass workpieces, for example:

[0074] Mechanical cutting (mainly drilling) is a method of shaping and processing materials by using a rotating multi-edged tool. Due to the hardness and brittleness of glass materials, traditional cutting is less efficient, more expensive, and the processing size is limited by the tool size, making it difficult to process microstructures.

[0075] Hot pressing involves placing a workpiece on a heated base plate and heating it. Then, pressure is applied to the workpiece surface using a mold. By controlling the heating temperature and pressurization time, the workpiece is softened, then hardened, and finally cooled to achieve the desired material shape. However, due to the tiny size of the microstructure and the non-uniformity of the thermal field, hot pressing demolding is extremely difficult and can easily cause the structural shape to collapse.

[0076] Ultrasonic machining is a technique that uses a tool vibrating at a small ultrasonic frequency to strike abrasive particles floating in a liquid, thereby gradually breaking the surface of the workpiece material. It is suitable for machining hard and brittle materials such as glass and ceramics. However, because the design, installation, and calibration of ultrasonic transducers are very complex, and the tool head wears down during machining, it is prone to dynamic imbalance and microcracks on the workpiece surface. Therefore, ultrasonic machining has a high cost and poor surface quality.

[0077] Laser processing utilizes a laser beam to irradiate the surface of a material, melting and vaporizing the surface material through localized thermal effects and photochemical reactions to achieve the desired shape. However, this processing method removes material through thermal effects, resulting in significant thermal stress and material deformation. Furthermore, laser processing often leaves noticeable thermal flaking at the edges of the workpiece, necessitating secondary processing to eliminate the effects of thermal deformation and flaking. Additionally, precision lasers are very expensive, leading to high equipment investment costs.

[0078] Abrasive waterjet machining is a processing technology that uses a high-speed jet of liquid mixed with fine abrasive particles ejected from a nozzle to collide with and shear the workpiece material, thereby achieving material shaping. Currently, abrasive waterjet machining is applied to glass cutting, shape modification, and surface finishing. However, due to the significant shearing force between the high-speed jet of abrasive and the workpiece, the edges and corners of the workpiece material are easily broken, resulting in poor microstructure machining effects. Furthermore, the abrasive flow circulation process requires advanced filtration systems, pressurization systems, and excellent machine tool rigidity, leading to high equipment investment costs.

[0079] In comparison, the template-type spark-assisted chemical etching apparatus and method of this invention are used for processing the surface of glass workpieces. By inducing discrete, multi-point array spark discharge plasma in a single step using a template tool electrode, an array microstructure is formed on the surface of the glass workpiece in a single step. Compared with the above processing methods, the processing efficiency can be significantly improved. The shape / pattern / arrangement area of ​​the array microstructure is determined by the structure of the template tool electrode. Compared with the above processing methods, the controllability and dimensional stability of the shape / pattern / arrangement area of ​​the array microstructure on the processed surface are better. The spark discharge plasma energy is used to promote high-temperature chemical etching of the workpiece material, thereby forming a specific microstructure on the material surface. It has the characteristics of no burrs, no cracks, no thermal deterioration layer, and can maintain the initial light transmittance. Compared with the above processing methods, it can achieve higher surface quality.

[0080] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof can be combined with each other unless otherwise specified.

Claims

1. A template-type spark-assisted chemical etching (SIE) apparatus, characterized in that, include: The reaction vessel has a accommodating cavity for holding the electrolyte; A template assembly includes a template tool electrode and an insulating template stacked together. A first array of hollow structures is formed on the template tool electrode, and a second array of hollow structures corresponding to the positions of the first array of hollow structures are formed on the insulating template. A fastener is provided for detachably mounting the template assembly and the workpiece to be processed within the accommodating cavity. The fastener is used to mount the workpiece on the side of the template tool electrode facing away from the insulating template. An auxiliary electrode is disposed within the accommodating cavity and is used to form an electric field with the template tool electrode. The template tool electrode is attached to the surface of the workpiece to be processed, and the insulating template covers the side of the template tool electrode away from the workpiece, so that the template tool electrode is only exposed to the electrolyte at the first array hollow structure.

2. The template-type spark-assisted chemical etching apparatus according to claim 1, characterized in that, The fastener includes a frame and a limiting step, wherein: The frame encloses to form an installation cavity, which is used to accommodate the template assembly and the workpiece. The frame is detachably connected to the reaction tank so that the workpiece, template tool electrode, and insulating template are sequentially stacked and fixed in the accommodating cavity. The limiting step protrudes inward from the inner wall of the frame to abut against the side of the insulating template away from the template tool electrode. An opening is formed between the limiting steps to communicate with the mounting cavity, so that a part of the workpiece surface is exposed to the receiving cavity through the first array hollow structure, the second array hollow structure and the opening.

3. The template-type spark-assisted chemical etching apparatus according to claim 2, characterized in that, The frame has wire holes that connect to the mounting cavity and are used to introduce wires to connect to the template tool electrode.

4. The template-type spark-assisted chemical etching apparatus according to claim 1, characterized in that, The first array hollow structure and the second array hollow structure have the same size.

5. The template-type spark-assisted chemical etching apparatus according to claim 1, characterized in that, The reaction tank includes a bottom wall and a side wall that enclose the accommodating cavity. The auxiliary electrode is fixed to the inner wall of the side wall, and the fixing member is installed on the bottom wall.

6. The template-type spark-assisted chemical etching apparatus according to claim 1, characterized in that, The thickness of the template tool electrode is 0.1 mm to 1 mm; and / or, the thickness of the insulating template is 0.1 mm to 1 mm.

7. The template-type spark-assisted chemical etching apparatus according to any one of claims 1 to 6, characterized in that, It also includes a power supply, with the auxiliary electrode electrically connected to the positive terminal of the power supply and the template tool electrode electrically connected to the negative terminal of the power supply.

8. A template-type spark-assisted chemical etching method using the template-type spark-assisted chemical etching apparatus according to any one of claims 1 to 7, characterized in that, The template tool electrode and the insulating template are sequentially stacked and covered on the surface of the workpiece. The template tool electrode and the auxiliary electrode are connected to a power source to form an electric field. In the electrolyte, the template tool electrode induces spark discharge plasma at the first array hollow structure, forming local spark-assisted chemical etching at the position on the workpiece surface corresponding to the first array hollow structure. After etching is completed, an array microstructure corresponding to the first array hollow structure is formed on the workpiece surface.

9. The template-based spark-assisted chemical etching method according to claim 8, characterized in that, The power supply outputs a pulse waveform, and processing is performed during the pulse phase, while electrolyte renewal is performed during the inter-pulse phase.

10. The template-type spark-assisted chemical etching method according to claim 8, wherein the microstructure formed on the workpiece surface is changed by replacing the template tool electrode with a different first array hollow structure and the insulating template with a corresponding and consistent second array hollow structure.

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