Microstructure master repair method

Abstract

The present application relates to the technical field of printed matter quality control, and discloses a microstructure master plate repairing method, which comprises the following steps: detecting the flatness of the microstructure master plate, and screening the master plate to be repaired; placing the master plate in a solvent to remove surface impurities; obtaining a mold pressing sample, and marking the microstructure defect point area on the mold pressing sample; hollowing out the microstructure defect point area on the mold pressing sample, and manufacturing a mask and a repair file according to the position and size of the microstructure defect point area; attaching the mask to the master plate to be repaired, and exposing the microstructure defect point area to the hollowed-out area; placing the master plate with the attached mask in a material filling device to fill the material; removing the mask on the master plate to be repaired, performing local pattern photolithography on the repair area of the master plate, and re-creating the microstructure, so that the damaged microstructure on the master plate can be accurately restored, thereby solving the problem that the traditional microstructure master plate cannot be repaired, improving the consistency and quality stability of the microstructure between batches, and ensuring the quality consistency between batches.

Description

Technical Field

[0001] This invention relates to the field of printing quality control technology, and in particular to a method for repairing microstructured master plates. Background Technology

[0002] The fabrication of microstructured materials is usually achieved by combining photolithography with molding replication. This process combines the high precision of photolithography with the high efficiency of molding, and is suitable for large-scale, low-cost production of micro- and nano-scale periodic or complex structures (such as gratings, photonic crystals, metasurfaces, etc.).

[0003] like Figure 1 and Figure 2 As shown, the fabrication process of the microstructure master mold typically involves creating multiple photolithographic glass templates for the micro-nano areas of the packaging product based on photolithography files. These templates are then assembled, and a master mold is fabricated based on the assembled templates. Finally, the master mold and the working template are molded together to create the working template. Figure 2 In (a) of the text, during printing, the printing plate presses the substrate to form microstructures, such as... Figure 2 Therefore, as in (b), the master copy serves as the basis for creating the working copy and is closest to the lithography file. Generally, the master copy is saved for repeated creation of the working copy.

[0004] In optical material embossing processes, the fabrication and maintenance of the master mold are crucial. The master mold may be damaged during use; common forms of damage include surface scratches and microstructural blockages, such as… Figure 3 As shown in (a) above, surface scratches can be transferred to the product during the imprinting process via the working plate, leading to batch defects. Even tiny scratches can disrupt the integrity of the nanoscale structure, thus affecting the material quality. Microstructural blockage, on the other hand, can cause incomplete information during imprinting, resulting in missing or deformed replicated structures, such as... Figure 3 As shown in (b) in the diagram. In the current packaging industry, once the printing master of optical materials is damaged, it can usually only be scrapped and remade.

[0005] Currently, master plate repair is not possible, leading to material waste, low work efficiency, and increased waste liquid discharge pressure due to the increased number of master plates produced. Therefore, there is an urgent need to provide a microstructure master plate repair method. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the purpose of this invention is to provide a microstructure master plate repair method that can solve the problem of existing master plates being unrepairable.

[0007] To solve the above technical problems, the present invention adopts the following technical solution: A method for repairing microstructure master plates, comprising: Flatness testing of microstructure master templates was conducted to select master templates to be repaired; The master plate to be repaired is placed in a solvent for surface pretreatment to remove residual impurities from the surface of the master plate to be repaired; Obtain the molding sample of the working plate corresponding to the master plate to be repaired, mark the microstructure defect area on the molding sample and obtain the size of the microstructure defect area; The microstructural defect areas on the molded sample are hollowed out, and a mask and repair file are made according to the position and size of the microstructural defect areas. The center point of the hollowed-out area on the mask is the same as the center point of the microstructural defect area, and the size of the hollowed-out area is larger than the size of the microstructural defect area. The repair file has a local pattern photolithography area, the center point of which is the same as the center point of the hollowed-out area, and the size of the local pattern photolithography area is larger than the size of the hollowed-out area. The mask is attached to the pre-treated master plate to be repaired, and the microstructural defect area is exposed in the hollow area. The master plate to be repaired with the mask attached is placed in the material filling device, and the repair area of ​​the master plate to be repaired is filled with material. Remove the mask from the master plate to be repaired, place the master plate to be repaired in a photolithography device, and have the photolithography device perform local pattern photolithography on the repair area of ​​the master plate to be repaired according to the repair file to repair the microstructure of the master plate to be repaired.

[0008] After removing the mask from the master plate to be repaired, placing the master plate to be repaired in a photolithography device, and having the photolithography device perform local pattern photolithography on the repair area of ​​the master plate to be repaired according to the repair file to repair the microstructure of the master plate, the process further includes: The photolithographically repaired microstructure master template is placed in a solvent for surface treatment. Remove solution and dust from the surface of the microstructure master plate.

[0009] The steps of performing flatness testing on the microstructure master template and screening master templates to be repaired include: The graphic side of the microstructure master is placed facing the first light-transmitting substrate and laid flat on the first light-transmitting substrate. The flatness of the microstructure master template is detected by wedge interferometry, and microstructure master templates with flatness higher than the preset value are selected as master templates to be repaired.

[0010] The step of using the wedge interferometry method to detect the flatness of the microstructure master template and selecting microstructure master templates with flatness higher than a preset value as master templates to be repaired includes: The second light-transmitting substrate is placed on one side of the microstructure master plate, and a preset angle is formed between it and the microstructure master plate; The second light-transmitting substrate is illuminated with a monochromatic light source to form alternating light and dark stripes on the second light-transmitting substrate. The microstructure master with a curvature of alternating light and dark stripes less than the set curvature is identified as the master to be repaired.

[0011] In the microstructure master plate repair method, when marking the microstructure defect area, the point where the pull gauge of the molded sample intersects with the seam is used as the origin of the coordinates to obtain the coordinates of the microstructure defect area.

[0012] In the microstructure master plate repair method, the size of the hollow area is 1-8mm larger than the size of the microstructure defect area, and the size of the local pattern photolithography area is 1-8mm larger than the size of the hollow area.

[0013] In the microstructure master plate repair method, when attaching the mask to the master plate to be repaired after surface pretreatment, the perforated mask is attached to the graphic side of the master plate to be repaired with the bite line and pull guide line of the mask as a reference.

[0014] The microstructure master repair method described herein includes the following steps when creating the repair file: Using the bite line and pull line as coordinates, the masking method is used to cover the graphic areas in the original photolithography file that do not need to be repaired, resulting in a local pattern area with the same shape and size as the cut-out area. The local pattern area is magnified to obtain the local pattern photolithography area, and the repair file is made based on the local pattern photolithography area.

[0015] In the microstructure master plate repair method described above, the master plate to be repaired, with a mask attached, is placed in a material filling device, and the repair area of ​​the master plate to be repaired is filled with material, including: A nickel target with a purity greater than or equal to 99.99% is set in the material filling equipment; The material filling equipment is evacuated and argon gas is introduced into it. When the high-voltage power supply is turned on, the argon gas is ionized by the high-voltage electric field to form plasma. The plasma bombards the nickel target, causing nickel atoms to be sputtered and deposited onto the surface of the microstructure master plate.

[0016] The microstructure master plate repair method described herein includes the following steps: removing the mask on the master plate to be repaired, placing the master plate to be repaired in a photolithography device, and having the photolithography device perform local pattern photolithography on the repair area of ​​the master plate to be repaired according to the repair file to repair the microstructure of the master plate to be repaired. Separate the mask from the master plate to be repaired; The back side of the master mold to be repaired, after the mask has been removed, is attached to the glass substrate and placed in a photolithography device; Import the repair file into the photolithography equipment, and align the pull line and bite line of the repair file with the pull line and bite line of the master plate to be repaired, so that the local pattern photolithography area coincides with the non-deposited pattern around the repair area of ​​the master plate to be repaired. The photolithography equipment etches microstructures in and around the repair area according to the repair file.

[0017] Compared to existing technologies, the microstructure master plate repair method provided by this invention achieves precise restoration of damaged microstructures on the master plate by sequentially performing surface flatness detection, surface pretreatment, material filling, and microstructure reconstruction on the microstructure master plate. This solves the problem that traditional microstructure master plates cannot be repaired. At the same time, the repaired master plate does not require plate assembly, which improves the consistency of microstructures and quality stability between batches and ensures consistent quality between batches. Attached Figure Description

[0018] Figure 1 This is a schematic diagram illustrating the fabrication process of a microstructure master template using existing technology.

[0019] Figure 2 This is a schematic diagram illustrating the existing technology of creating a working plate using a microstructured master plate, and the process of imprinting the substrate onto the working plate.

[0020] Figure 3 This is a schematic diagram of a damaged microstructure master plate and its imprint in the prior art.

[0021] Figure 4 The flowchart shows the microstructure master plate repair method provided by the present invention.

[0022] Figure 5 This is a schematic diagram illustrating the flatness detection of the microstructure master plate in the microstructure master plate repair method provided by the present invention.

[0023] Figure 6 This is a schematic diagram comparing the flatness detection of a flat master plate and a deformed master plate in the microstructure master plate repair method provided by the present invention.

[0024] Figure 7 This is a schematic diagram illustrating the marking of microstructure defect areas in the microstructure master plate repair method provided by the present invention.

[0025] Figure 8 This is a schematic diagram of the mask and repair file created in the microstructure master plate repair method provided by the present invention. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0027] It should be noted that when a component is referred to as being "mounted on," "fixed to," or "set on" another component, it can be directly on the other component or may have an intervening component present. When a component is referred to as being "connected to" another component, it can be directly connected to the other component or may have an intervening component present.

[0028] It should also be noted that the directional terms such as left, right, up, and down in the embodiments of the present invention are only relative concepts or are based on the normal use state of the product, and should not be considered as restrictive.

[0029] Please see Figure 4 The microstructure master plate repair method provided by the present invention includes: S1. Flatness Inspection: The flatness of the microstructure master template is inspected to screen the master templates to be repaired; S2. Surface pretreatment: The motherboard to be repaired is placed in a solvent for surface pretreatment to remove residual impurities from the surface of the motherboard to be repaired; S3, Defect Marking: Obtain the molding sample of the working plate corresponding to the master plate to be repaired, mark the micro-structure defect area on the molding sample and obtain the size of the micro-structure defect area; S4. Mask Fabrication and Application: The microstructural defect areas on the molded sample are hollowed out, and a mask and repair file are fabricated based on the position and size of the microstructural defect areas. The center point of the hollowed-out area on the mask is the same as the center point of the microstructural defect area, and the size of the hollowed-out area is larger than the size of the microstructural defect area. The repair file has a local pattern photolithography area, the center point of which is the same as the center point of the hollowed-out area, and the size of the local pattern photolithography area is larger than the size of the hollowed-out area. S5. Material filling: The mask is attached to the pre-treated master plate to be repaired, and the microstructure defect area is exposed in the hollow area. The master plate to be repaired with the mask attached is placed in the material filling device, and the repair area of ​​the master plate to be repaired is filled with material. S6. Microstructure reconstruction: Remove the mask on the master plate to be repaired, place the master plate to be repaired in a photolithography device, and the photolithography device performs local pattern photolithography on the repair area of ​​the master plate to be repaired according to the repair file to repair the microstructure of the master plate to be repaired.

[0030] This invention achieves precise restoration of damaged microstructures by sequentially performing processes such as surface flatness detection, surface pretreatment, marking of defects in the master template, mask fabrication and attachment, material filling, and microstructure reconstruction on the microstructure master template. This solves the problem of traditional microstructure master templates being unable to repair, effectively reduces bottlenecks in the photolithography process, reduces the number of panel assembly steps, and thus improves the consistency and quality stability of microstructures between batches, ensuring consistent quality across batches.

[0031] Furthermore, the microstructure master plate repair method of the present invention further includes, after step S6, a step processing of the photolithographically repaired microstructure master plate. Optionally, this includes: S71. Place the photolithographically repaired microstructure master in a solvent for surface treatment; S72. Remove solution and dust from the surface of the microstructure master plate.

[0032] In an optional embodiment, step S1 includes: S11. Place the graphic side of the microstructure master plate facing the first light-transmitting substrate and lay it flat on the first light-transmitting substrate. S12. The flatness of the microstructure master plate is detected by wedge interference method, and microstructure master plates with flatness higher than the preset value are selected as master plates to be repaired.

[0033] The first light-transmitting substrate is a light-transmitting glass substrate; please refer to [link / reference]. Figure 5 and Figure 6 When performing flatness testing, the first glass substrate is placed first, and then the side of the microstructure master plate with graphics is placed face down on the first glass substrate to make it fully unfolded and flattened. It is then fixed to the glass plate with glue. At this time, the back of the microstructure master plate faces up as the flatness testing surface. Since this testing surface does not have microstructures, the accuracy of the flatness testing is ensured.

[0034] In step S12, when detecting the flatness of the microstructure master plate using the wedge interferometry method, the following steps are included: S121. Place the second light-transmitting substrate on one side of the microstructure master plate and form a preset angle between it and the microstructure master plate. S122. Illuminate the second light-transmitting substrate with a monochromatic light source to form alternating light and dark stripes on the second light-transmitting substrate. S123. The microstructure master with a curvature of alternating light and dark stripes less than the set curvature is identified as the master to be repaired.

[0035] The second light-transmitting substrate also uses a glass substrate, such as Figure 5 and Figure 6As shown, during flatness testing, a second glass substrate (i.e., a second transparent substrate) is placed on one side of the back of the microstructure master plate, forming an angle θ with the microstructure master plate. This creates a wedge-shaped air film between the second transparent substrate and the smooth surface of the master plate (i.e., the back of the microstructure master plate). A monochromatic light source is then used to illuminate the second transparent substrate from above. Due to wedge interference, alternating bright and dark fringes appear. When the microstructure master plate is not placed on the lower glass substrate (i.e., the first transparent substrate) or the microstructure master plate is flat, the resulting bright and dark fringes are as follows: Figure 6 As shown in (a), the fringe spacing is obtained from the above formula: ΔL=λ / 2nθ Where λ is the wavelength of the incident light, n is the refractive index of the wedge medium (n≈1 if it is air), and θ is the wedge angle. From the above formula, it can be seen that if the back of the master plate is concave towards the front, the angle θ increases, and the stripes become denser; if the front of the master plate is concave towards the back, the angle θ decreases, and the stripe spacing increases. Therefore, if the microstructure master plate is uneven, the angle between the concave or protruding area and the second transparent substrate changes, causing the straight light columns of the stripes to bend, resulting in a shape like... Figure 7 The curved stripes shown in (b) are shown in the image.

[0036] Taking red light as an example (since red light is monochromatic, in...) Figure 6 The downward-pointing gray arrows and gray stripes appear red during actual testing (this red is distinguished as bright stripes, while the black areas are dark stripes). If illuminated with 650nm red light, θ = 10. -4 If rad and n≈1, then the fringe spacing ΔL is 6.5mm. If the back of the microstructure master has protrusions or depressions, the fringe spacing will change significantly, which can be observed directly visually. Figure 6 As shown in (b), if the stripe curvature is small, it indicates that there is no obvious bending, that is, the flatness of the master plate is high. In this case, the master plate can be used as a repairable master plate and is selected for subsequent microstructure repair. If the stripe is obviously bent during the test, the microstructure master plate is severely deformed and cannot be repaired. In this case, the microstructure master plate can be scrapped.

[0037] In an optional embodiment, flatness screening can be performed visually based on the experience of the staff. For example, by visually inspecting the bright and dark stripes from one meter away from the second light-transmitting substrate, if the bright and dark stripes are significantly curved, the microstructure master template is scrapped. If the bright and dark stripes are not significantly curved, they can be used as the screened repairable microstructure master template, i.e., the master template to be repaired. Of course, the present invention can also use existing curve curvature calculation methods to calculate the curvature at the curvature of the bright and dark stripes, and set the curvature to be less than a set value, such as less than or equal to 2m. -1 The time indicates that the master template is relatively flat, and it can be used as a repairable microstructure master template. Specific selection can be made according to needs.

[0038] This invention can also use the wedge interference method to detect the surface flatness of the working plate, avoiding the discovery of working plate deformation only when the working plate is being molded, which would lead to defective products and improve the yield of molded products.

[0039] The selected master templates to be repaired are removed from the first glass substrate, and surface impurities are removed from the master templates to be repaired. This is to remove residual UV varnish on the master templates to be repaired, so as to facilitate more precise reconstruction and repair of microstructural damage areas. During surface pretreatment, a low-concentration NaOH-DMSO solution can be prepared to dissolve impurities on the surface of the master templates to be repaired.

[0040] Optionally, the low-concentration NaOH-DMSO solution is prepared from dimethyl sulfoxide (DMSO), sodium hydroxide (NaOH), and water. Dimethyl sulfoxide (DMSO) has strong dissolving power and is used to penetrate the UV coating and swell the cross-linked structure, while sodium hydroxide (NaOH) provides an alkaline environment to break the chemical bonds (such as ester and ether bonds) of the UV varnish.

[0041] Optionally, the low-concentration NaOH-DMSO solution can be prepared by mixing 70-90% dimethyl sulfoxide (DMSO), 5-15% sodium hydroxide (NaOH), and 5%-10% water. After obtaining the low-concentration NaOH-DMSO solution, it can be placed in a container filled with water and heated to 40-60°C. Then, the master plate to be repaired is immersed in the heated NaOH-DMSO solution for 10 minutes to dissolve impurities on both the image and non-image surfaces of the master plate.

[0042] In one specific embodiment, a solution prepared with a mass ratio of 80% DMSO, 10% NaOH, and 10% water has a better effect on the surface treatment of the master plate to be repaired.

[0043] During the dissolution reaction, 5-10% by mass of ethanol can be added to the NaOH-DMSO solution to improve the dissolving power of the NaOH-DMSO solution on the resin, depending on the reaction conditions.

[0044] Furthermore, the present invention can also place the prepared NaOH-DMSO solution in an ultrasonic cleaning device, and further enhance the dissolving power of the NaOH-DMSO solution by using ultrasonic vibration.

[0045] In step S3, when marking defects, a complete set of molded sheets that have been molded by the working sheet corresponding to the master sheet to be repaired can be taken as a molded sample, and then the microstructure defect areas are marked on the molded sample.

[0046] Please see Figure 7When marking the microstructural defect area, the point where the pull gauge of the molded sample intersects with the seam is used as the origin of the coordinate system to obtain the coordinates of the microstructural defect area. At this time, the coordinates and size of the microstructural defect area can be obtained based on this position.

[0047] In step S4, after marking all microstructural defect areas on the molding sample, the microstructural defect areas are enlarged using the center of each microstructural defect area as the base point. These enlarged microstructural defect areas are then cut and hollowed out on the molding sample to obtain hollowed-out areas, thus creating a hollowed-out mask. The shape of the hollowed-out area of ​​the mask is the same as that of the microstructural defect areas, but the size is slightly larger than that of the microstructural defect areas, such as 1.2 times the size of the microstructural defect areas, so that the microstructural defects and their surrounding areas can be filled with filling material later.

[0048] When attaching the mask to the pre-treated master template, the cutout mask is attached to the graphic side of the master template using the bite line and pull gauge line as references. In this embodiment, the graphic side of the master template is facing upwards, and the back of the master template is attached to a glass plate. When attaching the mask, the cutout mask is attached to the master template using the bite line and pull gauge lines of the molded sample as references, so that all microstructural defects on the master template are exposed in the cutout area. This invention directly uses the bite line and pull gauge line as references to achieve high alignment accuracy between the mask and the master template, and eliminates the need to locate the area to be repaired on the master template.

[0049] In step S4, when creating the repair file, the following is included: S41. Using the two sides of the bite line and the pull guide line as coordinates, use the masking method to cover the graphic areas in the original photolithography file that do not need to be repaired, and obtain a local pattern area with the same shape and size as the hollowed-out area. S42. Enlarge the local pattern area to obtain a local pattern photolithography area, and create the repair file based on the local pattern photolithography area.

[0050] When repairing a file, the coordinates of the cutout area of ​​the mask are first obtained. Then, based on the coordinates and shape of the cutout area, a mask is used in the original photolithography file to cover the normal graphic area (i.e., the area that does not need repair), retaining the local pattern area corresponding to the cutout area. At this time, the shape and size of the local pattern area are the same as those of the cutout area. Then, using the center of the local pattern area as the base point, the local pattern area is enlarged to form a local pattern photolithography area, such as 1.2 times the size of the local pattern area. The corresponding photolithography image and text are obtained according to the original photolithography file, thus obtaining the repaired file. This modified file is the modified file for laser direct writing during subsequent microstructure reconstruction. In this embodiment, the perimeter of the local pattern photolithography area of ​​the repaired file is made larger than the perimeter of the cutout area of ​​the mask, so that the graphic microstructure and the area to be repaired in the master plate are smoothly transitioned during microstructure reconstruction.

[0051] Optionally, the size of the hollowed-out area is 1-8 mm larger than the size of the microstructure defect area, and the size of the local pattern photolithography area is 1-8 mm larger than the size of the hollowed-out area.

[0052] Preferably, please refer to Figure 8 The size of the hollowed-out area is such that it extends at least 2mm outwards from the microstructural defect area on all four sides. That is, the size of the hollowed-out area is at least 4mm wider and 4mm longer than the microstructural defect area. The size of the local pattern photolithography area is such that it extends at least 2mm outwards from the hollowed-out area on all four sides, ensuring that the area of ​​the master plate requiring repair (i.e., the microstructural defect area) is fully exposed during deposition and laser direct writing. This allows for a smooth transition between the directly written microstructure and the area requiring no repair during subsequent microstructure reconstruction.

[0053] In the process of creating the mask and repairing the file, this invention uses its own molding product to create the mask. The mask's cutout area is at least 2mm larger than the defective area on all sides. The photolithographic repair file is created according to the bite and pull gauge sides as coordinates. The photolithographic repair file uses a masking method to cover the non-cutout areas of the original file, exposing the photolithographic images of the cutout areas of the original file. The area of ​​this image area is at least 2mm larger than the cutout area of ​​the mask on all sides. This method realizes the reconstruction of the microstructure images of the defective areas of the master plate and their surrounding areas, and the transition with the original microstructure images of the master plate is smooth, thereby ensuring the consistency and quality stability of the microstructure between batches.

[0054] Optionally, in step S5, the master template to be repaired, with the mask attached, is placed in a material filling device, and the repair area of ​​the master template to be repaired is filled with material, including: S51. A nickel target with a purity greater than or equal to 99.99% is set in the material filling equipment; S52. Vacuum the material filling equipment and introduce argon gas into it. S53. Connect the high-voltage power supply, ionize the argon gas through the high-voltage electric field to form plasma, and bombard the nickel target with the plasma to sputter and deposit nickel atoms onto the surface of the microstructure master plate.

[0055] (1) In one specific embodiment, the master template to be repaired, with a mask attached, is placed in a single-sheet magnetron sputtering apparatus, using a high-purity nickel target of ≥99.99%, and the vacuum environment is controlled at 10. -3 -10 -6 Pa, and argon gas is introduced, and the argon gas is ionized using a high-voltage electric field (DC / RF) to form plasma Ar. + Ar + The Ni target is bombarded, causing Ni atoms to sputter and deposit onto the surface of the master substrate. During deposition, the thickness varies depending on the type of master substrate material, and the deposited thickness is greater than the original microstructure thickness on the master substrate. For example, if the depth of the holographic grating microstructure on the master substrate is 1 μm, the depth of the anti-counterfeiting element microstructure is 2 μm, and the depth of the microlens array microstructure is 10 μm, then the deposition thickness of the holographic grating is 2 μm, the deposition thickness of the anti-counterfeiting element is 4 μm, and the deposition thickness of the microlens array is 12 μm, so as to facilitate the restoration of the microstructure of the master substrate during subsequent direct writing.

[0056] After depositing and filling the areas to be cut out on the master template, the laser direct writing step can proceed, which includes: S61. Separate the mask from the master plate to be repaired; S62. Attach the back side of the master mold to be repaired after removing the mask to the glass substrate and place it in the photolithography equipment. S63. Import the repair file into the photolithography equipment, and align the pull line and bite line of the repair file with the pull line and bite line of the master plate to be repaired, so that the local pattern photolithography area coincides with the non-deposited pattern around the repair area of ​​the master plate to be repaired. S64. The photolithography equipment etches microstructures in the repair area and the periphery of the repair area according to the repair file.

[0057] In this embodiment of the invention, after the master plate to be repaired is deposited, the mask is first separated from the master plate, and then the master plate and the glass plate are placed together in the photolithography platform. The local pattern (i.e., the repair file) is imported into the laser direct writing device (i.e., the photolithography device). In the photolithography system, the pull line and bite line of the repair file are aligned with the pull line and bite line of the actual master plate, so that the repair file coincides with the non-deposited graphics and text around the defect area of ​​the master plate. That is, the part of the edge of the photolithography area of ​​the local pattern that exceeds the hollow area (i.e., the master plate filling area) is aligned with the graphics and text area on the master plate that does not need to be repaired. Then, the laser direct writing device uses a laser to directly etch the microstructure in the deposited filler area according to the repair file.

[0058] During photolithography, this embodiment employs a femtosecond-level short-pulse laser with an extremely short pulse width of approximately 10-15 seconds. The laser power density is on the order of 10⁸-10¹² watts per square centimeter. Through nonlinear absorption, it can efficiently vaporize elemental nickel, reducing the heat-affected zone. During laser direct writing, an inert gas (such as argon) is introduced into the photolithography equipment, which is then sealed, and the argon gas is kept circulating and filtered to prevent nickel from reacting with oxygen in the air to form NiO during vaporization.

[0059] This invention uses laser direct etching of nickel material, which reduces the copying process, improves the efficiency of master plate repair, and also reduces plate assembly, ensuring the consistency of microstructure and quality stability of the molding between batches.

[0060] Furthermore, after the master mold to be repaired undergoes microstructural reconstruction, it needs to be placed in a low-concentration NaOH-DMSO solution to dissolve any remaining adhesive residue on the surface. After cleaning, it can be placed in a negative pressure environment and vacuumed to remove the solution and dust from both sides. The low-concentration NaOH-DMSO solution used in the surface pretreatment described above can be employed.

[0061] In summary, this invention, through a process of flatness screening, surface pretreatment, microstructure marking, mask fabrication, material filling, microstructure reconstruction, and surface treatment, achieves repairability of microstructure master plates for the first time, completely avoiding the waste of plate materials and waste liquid discharge caused by the traditional "damage equals scrap" approach, significantly reducing production costs and alleviating environmental pressure.

[0062] This invention employs a triple alignment mechanism of molded sample defect coordinates, mask, and repair file. The hollowed-out area is highly consistent with the original plate's microstructure in terms of morphology, depth, and line width, ensuring consistent optical performance of subsequent batches of products printed from the working plate and eliminating quality fluctuations caused by plate changes.

[0063] Meanwhile, the master plate repair process skips the steps of re-layouting, full set of photolithography, and multiple molding verification, greatly reducing the cycle of needing to remake the master plate, while reducing the number of times the photolithography equipment is turned on and the consumption of consumables such as nickel targets and glass substrates, significantly improving plate-making efficiency and reducing operating costs.

[0064] Moreover, the deposition thickness can be precisely set according to the depth (2–12 µm) of different microstructures such as holographic gratings, anti-counterfeiting elements, and microlens arrays. Combined with femtosecond laser direct writing, it can complete the local reconstruction of various structural types on the same master plate, with strong process compatibility.

[0065] The repaired master template can be directly reused to make working templates, realizing a "damage-repair-reuse" cycle, which significantly extends the life cycle of the master template and is particularly suitable for the production of high-volume, high-value-added optical packaging materials.

[0066] It is understood that those skilled in the art can make equivalent substitutions or modifications to the technical solution and inventive concept of the present invention, and all such substitutions or modifications should fall within the protection scope of the appended claims.

Claims

1. A method for repairing microstructure master plates, characterized in that, include: Flatness testing of microstructure master templates was conducted to select master templates to be repaired; The master plate to be repaired is placed in a solvent for surface pretreatment to remove residual impurities from the surface of the master plate to be repaired; Obtain the molding sample of the working plate corresponding to the master plate to be repaired, mark the microstructure defect area on the molding sample and obtain the size of the microstructure defect area; The microstructural defect areas on the molded sample are hollowed out, and a mask and repair file are made according to the position and size of the microstructural defect areas. The center point of the hollowed-out area on the mask is the same as the center point of the microstructural defect area, and the size of the hollowed-out area is larger than the size of the microstructural defect area. The repair file has a local pattern photolithography area, the center point of which is the same as the center point of the hollowed-out area, and the size of the local pattern photolithography area is larger than the size of the hollowed-out area. The mask is attached to the pre-treated master plate to be repaired, and the microstructural defect area is exposed in the hollow area. The master plate to be repaired with the mask attached is placed in the material filling device, and the repair area of ​​the master plate to be repaired is filled with material. Remove the mask from the master plate to be repaired, place the master plate to be repaired in a photolithography device, and have the photolithography device perform local pattern photolithography on the repair area of ​​the master plate to be repaired according to the repair file to repair the microstructure of the master plate to be repaired.

2. The microstructure master plate repair method according to claim 1, characterized in that, After removing the mask from the master plate to be repaired, placing the master plate to be repaired in a photolithography device, and having the photolithography device perform local pattern photolithography on the repair area of ​​the master plate to be repaired according to the repair file to repair the microstructure of the master plate, the process further includes: The photolithographically repaired microstructure master template is placed in a solvent for surface treatment. Remove solution and dust from the surface of the microstructure master plate.

3. The microstructure master plate repair method according to claim 1, characterized in that, The steps of performing flatness testing on the microstructure master template and screening master templates to be repaired include: The graphic side of the microstructure master is placed facing the first light-transmitting substrate and laid flat on the first light-transmitting substrate. The flatness of the microstructure master template is detected by wedge interferometry, and microstructure master templates with flatness higher than the preset value are selected as master templates to be repaired.

4. The microstructure master plate repair method according to claim 3, characterized in that, The step of using the wedge interferometry method to detect the flatness of the microstructure master template and selecting microstructure master templates with flatness higher than a preset value as master templates to be repaired includes: The second light-transmitting substrate is placed on one side of the microstructure master plate, and a preset angle is formed between it and the microstructure master plate; The second light-transmitting substrate is illuminated with a monochromatic light source to form alternating light and dark stripes on the second light-transmitting substrate. The microstructure master with a curvature of alternating light and dark stripes less than the set curvature is identified as the master to be repaired.

5. The microstructure master plate repair method according to claim 1, characterized in that, When marking the microstructural defect area, the point where the pull gauge of the molded sample intersects with the seam is used as the origin of the coordinate system to obtain the coordinates of the microstructural defect area.

6. The microstructure master plate repair method according to claim 1 or 5, characterized in that, The size of the hollowed-out area is 1-8 mm larger than the size of the microstructure defect area, and the size of the local pattern photolithography area is 1-8 mm larger than the hollowed-out area.

7. The microstructure master plate repair method according to claim 6, characterized in that, When attaching the mask to the pre-treated master plate, the cutout mask is attached to the graphic side of the master plate with the bite line and pull line of the mask as a reference.

8. The microstructure master plate repair method according to claim 1, characterized in that, When creating the repair file, the following should be included: Using the bite line and pull line as coordinates, the masking method is used to cover the graphic areas in the original photolithography file that do not need to be repaired, resulting in a local pattern area with the same shape and size as the cut-out area. The local pattern area is magnified to obtain the local pattern photolithography area, and the repair file is made based on the local pattern photolithography area.

9. The microstructure master plate repair method according to claim 1, characterized in that, The master template to be repaired, with a mask attached, is placed in the material filling device, and the repair area of ​​the master template is filled with material, including: A nickel target with a purity greater than or equal to 99.99% is set in the material filling equipment; The material filling equipment is evacuated and argon gas is introduced into it. When the high-voltage power supply is turned on, the argon gas is ionized by the high-voltage electric field to form plasma. The plasma bombards the nickel target, causing nickel atoms to be sputtered and deposited onto the surface of the microstructure master plate.

10. The microstructure master plate repair method according to claim 1, characterized in that, The steps of removing the mask on the master plate to be repaired, placing the master plate to be repaired in a photolithography device, and having the photolithography device perform local pattern photolithography on the repair area of ​​the master plate to be repaired according to the repair file to repair the microstructure of the master plate to be repaired include: Separate the mask from the master plate to be repaired; The back side of the master mold to be repaired, after the mask has been removed, is attached to the glass substrate and placed in a photolithography device; Import the repair file into the photolithography equipment, and align the pull line and bite line of the repair file with the pull line and bite line of the master plate to be repaired, so that the local pattern photolithography area coincides with the non-deposited pattern around the repair area of ​​the master plate to be repaired. The photolithography equipment etches microstructures in and around the repair area according to the repair file.

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