Microstructure master mask repairing method

Abstract

The invention relates to the technical field of printed matter quality control, and discloses a microstructure master mask repairing method which comprises the following steps: detecting the flatness of a microstructure master mask, and screening a to-be-repaired master mask; placing the mother set in a solvent to remove impurities on the surface; a mold pressing sample sheet is obtained, and a microstructure defect spot area on the mold pressing sample sheet is marked; carrying out hollowing-out treatment on the microstructure defect spot area on the mould pressing sample sheet, and manufacturing a mask and a repair file according to the position and the size of the microstructure defect spot area; the mask is attached to the mother set to be repaired, the micro-structure defect spot area is exposed out of the hollowed-out area, and the mother set attached with the mask is placed in material filling equipment for material filling; according to the method, the mask on the mother set to be repaired is removed, and local pattern photoetching and microstructure reconstruction are carried out on the repaired area of the mother set, so that the damaged microstructure on the mother set can be accurately recovered, the problem that a traditional microstructure mother set cannot be repaired is solved, the consistency and quality stability of microstructures among batches are improved, and the production cost is reduced. And the quality consistency between batches is ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of printed matter quality control, and in particular to a microstructure master plate repair method. BACKGROUND

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

[0003] As shown in Figure 1 and Figure 2 , the manufacturing process of a microstructure master plate usually involves creating multiple photolithography glass original plates for the micro / nano regions of the packaging product according to a photolithography file, then assembling the original plates, and then manufacturing a master plate based on the assembly. The master plate is then used to mold a working plate, as shown in Figure 2 (a). During printing, the working plate is used to emboss the microstructure onto the substrate, as shown in Figure 2 (b). Therefore, the master plate serves as the basis for manufacturing the working plate and is closest to the photolithography file, so it is generally saved for repeated production of working plates.

[0004] In the optical material embossing process, the manufacturing and maintenance of the master plate are crucial. The master plate may be damaged during use, and common forms of damage include surface scratches and microstructure blockages, as shown in Figure 3 (a). Surface scratches can be transferred to the product during the embossing process through the working plate, resulting in batch defects. Even a small scratch can damage the integrity of the nano-scale structure, which in turn affects the quality of the material. Microstructure blockages can cause incomplete information during embossing, resulting in missing or distorted replicated structures, as shown in Figure 3 (b). In the current packaging industry, once the optical material embossing master plate is damaged, it can only be directly scrapped and a new one must be manufactured.

[0005] Currently, the master plate cannot be repaired, resulting in waste of plate materials, low work efficiency, and increased number of master plate production, which increases the pressure of waste liquid discharge. Therefore, there is an urgent need to provide a microstructure master plate repair method. SUMMARY

[0006] In view of the above shortcomings of the prior art, the purpose of the present application is to provide a microstructure master plate repair method that can solve the problem of non-repairable master plates.

[0007] To solve the above technical problems, the present application adopts the following technical solutions: A microstructure master plate repair method, comprising The flatness of the microstructure master is detected, and a master to be repaired is screened out; The master to be repaired is placed in a solvent for surface pretreatment to remove residual impurities on the surface of the master to be repaired; A mold pressing sample corresponding to the master to be repaired is obtained, the microstructure defect area is marked on the mold pressing sample, and the size of the microstructure defect area is obtained; The microstructure defect area on the mold pressing sample is hollowed out, and a mask and a repair file are made according to the position and size of the microstructure defect area; wherein the center point of the hollowed-out area on the mask is the same as the center point of the microstructure defect area, and the size of the hollowed-out area is larger than the size of the microstructure defect area; the repair file has a local pattern lithography area, the center point of the local pattern lithography area is the same as the center point of the hollowed-out area, and the size of the local pattern lithography area is larger than the size of the hollowed-out area; The mask is attached to the master to be repaired after surface pretreatment, and the microstructure defect area is exposed to the hollowed-out area, and the master to be repaired with the mask is placed in a material filling device to fill the repair area of the master to be repaired with material; The mask on the master to be repaired is removed, and the master to be repaired is placed in a lithography device to perform local pattern lithography on the repair area of the master to be repaired according to the repair file, and the microstructure of the master to be repaired is repaired.

[0008] After the step of removing the mask on the master to be repaired, placing the master to be repaired in a lithography device, and performing local pattern lithography on the repair area of the master to be repaired according to the repair file to repair the microstructure of the master to be repaired, the method further comprises: The microstructure master after lithographic repair is placed in a solvent for surface treatment; The solution and dust on the surface of the microstructure master are removed.

[0009] The step of detecting the flatness of the microstructure master and screening the master to be repaired comprises: The graphic side of the microstructure master is placed on the first light-transmitting substrate and laid flat on the first light-transmitting substrate; The flatness of the microstructure master is detected by using the wedge interference method, and the microstructure master with a flatness higher than a preset value is selected as the master to be repaired.

[0010] The step of detecting the flatness of the microstructure master by using the wedge interference method and selecting the microstructure master with a flatness higher than a preset value as the master to be repaired comprises: The second light-transmitting substrate is placed on one side of the microstructure master and forms a preset included angle with the microstructure master; Irradiate the second light-transmitting substrate with a monochromatic light source to form light-and-dark alternating stripes on the second light-transmitting substrate. The microstructure master plate with the curvature of the light-and-dark alternating stripes less than the set curvature is determined as the master plate to be repaired.

[0011] In the microstructure master plate repair method, when marking the microstructure defect point area, the intersection point of the die sample drawing gauge and the bite line is used as the coordinate origin to obtain the coordinates of the microstructure defect point area.

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

[0013] In the microstructure master plate repair method, when the mask is attached to the surface pretreated master plate to be repaired, the mask with the hollow part is attached to the text side of the master plate to be repaired based on the bite line and the drawing gauge line of the mask.

[0014] In the microstructure master plate repair method, when the repair file is made, the method comprises: The mask method is used to shield the text area that does not need to be repaired in the original photoetching file, taking the bite line and the drawing gauge line on both sides as the coordinates, to obtain a local pattern area with the same shape and size as the hollow area; The local pattern area is enlarged to obtain a local pattern photoetching area, and the repair file is made according to the local pattern photoetching area.

[0015] In the microstructure master plate repair method, the master plate to be repaired with the mask attached is placed in a material filling device to fill the material in the repair area of the master plate to be repaired, which comprises: A nickel target with a nickel content of greater than or equal to 99.99% is arranged in the material filling device; The material filling device is subjected to vacuum treatment, and argon gas is introduced into the material filling device; The high-voltage power supply is turned on, the argon gas is ionized by the high-voltage electric field to form a plasma, and the plasma bombards the nickel target to make nickel atoms sputter and deposit on the surface of the microstructure master plate.

[0016] In the microstructure master plate repair method, the mask is removed from the master plate to be repaired, and the master plate to be repaired is placed in a photoetching device to perform local pattern photoetching on the repair area of the master plate to be repaired according to the repair file, thereby repairing the microstructure of the master plate to be repaired. The mask is separated from the master plate to be repaired; The back surface of the master plate to be repaired after the mask is removed is attached to a glass substrate, and the master plate to be repaired is placed in a photoetching device; Import the repair file into the lithography equipment, and align the gage lines and kiss lines of the repair file with the gage lines and kiss lines of the master to be repaired respectively, so that the partial pattern lithography area coincides with the non-deposited graphic periphery of the repair area of the master to be repaired; The lithography equipment etches the microstructure in the repair area and the periphery of the repair area according to the repair file.

[0017] Compared with the prior art, the microstructure master repair method provided by the application can accurately restore the damaged microstructure on the master, thereby solving the problem that the traditional microstructure master cannot be repaired, and the repaired master does not need to be spliced, thereby improving the consistency and quality stability of the microstructure between batches and ensuring the quality consistency between batches. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a schematic diagram of the manufacturing process of the microstructure master of the prior art.

[0019] Figure 2 It is a schematic diagram of the manufacturing process of the microstructure master of the prior art.

[0020] Figure 3 It is a schematic diagram of the damaged microstructure master and its impression of the prior art.

[0021] Figure 4 It is a flowchart of the microstructure master repair method provided by the application.

[0022] Figure 5 It is a schematic diagram of the flatness detection of the microstructure master in the microstructure master repair method provided by the application.

[0023] Figure 6 It is a schematic diagram of the flatness detection of the flat master and the deformed master in the microstructure master repair method provided by the application.

[0024] Figure 7 It is a schematic diagram of the microstructure defect area marking in the microstructure master repair method provided by the application.

[0025] Figure 8 It is a schematic diagram of the mask and the repair file manufactured in the microstructure master repair method provided by the application. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical scheme and advantages of the application clearer, the application will be further described in detail below with reference to the drawings and examples. It should be understood that the specific examples described herein are only used to explain the application and do not limit the application.

[0027] It should be noted that when a component is referred to as being "mounted on", "fixed on" or "disposed on" another component, it can be directly on the other component or a middle component can be present at the same time. When a component is referred to as being "connected to" another component, it can be directly connected to the other component or a middle component can be present at the same time.

[0028] It should also be noted that the left, right, up, down and other orientation terms in the embodiments of the present application are only relative concepts or are referenced to the normal use state of the product, and should not be considered as limiting.

[0029] Please refer to Figure 4 The microstructure master repair method provided by the present application comprises: S1, flatness detection: detecting the flatness of the microstructure master, and screening the master to be repaired; S2, surface pretreatment: placing the master to be repaired in a solvent for surface pretreatment to remove residual impurities on the surface of the master to be repaired; S3, defect point marking: obtaining a mold pressing sample corresponding to the working version mold pressing of the master to be repaired, marking the microstructure defect point area on the mold pressing sample, and obtaining the size of the microstructure defect point area; S4, mask making and attaching: hollowing the microstructure defect point area on the mold pressing sample, and making a mask and a repair file according to the position and size of the microstructure defect point area; wherein the center point of the hollowed area on the mask is the same as the center point of the microstructure defect point area, and the size of the hollowed area is greater than the size of the microstructure defect point area; the repair file has a local pattern lithography area, the center point of the local pattern lithography area is the same as the center point of the hollowed area, and the size of the local pattern lithography area is greater than the size of the hollowed area; S5, material filling: attaching the mask to the master to be repaired after surface pretreatment, and exposing the microstructure defect point area to the hollowed area, and placing the master to be repaired with the attached mask in a material filling device to fill the repair area of the master to be repaired with material; S6, microstructure reconstruction: removing the mask on the master to be repaired, and placing the master to be repaired in a lithography device to perform local pattern lithography on the repair area of the master to be repaired according to the repair file, and repairing the microstructure of the master to be repaired.

[0030] The microstructure master plate repairing method of the present application can accurately restore the damaged microstructure, thereby solving the problem that the traditional microstructure master plate cannot be repaired, effectively reducing the photolithography process bottleneck, reducing the number of plate splicing, thereby improving the consistency and quality stability of the microstructure between batches, and ensuring the quality consistency between batches.

[0031] Further, the microstructure master plate repairing method of the present application further comprises a step of processing the photolithographically repaired microstructure master plate after step S6. Optionally, it comprises: S71, placing the photolithographically repaired microstructure master plate in a solvent for surface treatment; S72, removing the solution and dust on the surface of the microstructure master plate.

[0032] In an optional embodiment, the step S1 comprises: S11, placing the graphic side of the microstructure master plate against the first light-transmitting substrate and laying it on the first light-transmitting substrate; S12, detecting the flatness of the microstructure master plate by using the wedge interference method, and screening the microstructure master plate with a flatness higher than a preset value as the repaired master plate.

[0033] The first light-transmitting substrate is a light-transmitting glass substrate, please refer to Figure 5 and Figure 6 When detecting the flatness, first place the first glass substrate, then place the microstructure master plate with the side with graphics facing down to the first glass substrate, so that it is completely unfolded and laid flat, and fix it on the glass plate with glue. At this time, the back of the microstructure master plate is upward as the detection surface of the flatness. Since the detection surface has no microstructure, the accuracy of the flatness detection is ensured.

[0034] In step S12, when detecting the flatness of the microstructure master plate by using the wedge interference method, it comprises: S121, placing the second light-transmitting substrate on one side of the microstructure master plate and forming a preset included angle between the second light-transmitting substrate and the microstructure master plate; S122, using a monochromatic light source to irradiate the second light-transmitting substrate, so that the second light-transmitting substrate forms alternating bright and dark stripes; S123, determining the microstructure master plate with a curvature of the alternating bright and dark stripes less than a set curvature as the repaired master plate.

[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] The present application can also detect the flatness of the working plate by the wedge interference method, so that the deformation of the working plate is found only when the working plate is used for mold pressing, resulting in waste products, and the yield of the mold pressing products is improved.

[0039] The repaired master plate is removed from the first glass substrate, and the surface impurities of the repaired master plate are removed. Here, the UV oil remaining on the repaired master plate is removed to facilitate more accurate repair of the microstructure damage area. During surface pretreatment, a low-concentration NaOH-DMSO solution can be optionally prepared to dissolve the impurities on the surface of the repaired master plate.

[0040] Alternatively, the low-concentration NaOH-DMSO solution is prepared from dimethyl sulfoxide (DMSO), sodium hydroxide (NaOH), and water. The dimethyl sulfoxide (DMSO) has strong solubility and is used to penetrate the UV coating and swell the cross-linked structure, and the sodium hydroxide (NaOH) is used to provide an alkaline environment to break the chemical bonds (such as ester bonds and ether bonds) of the UV oil.

[0041] Alternatively, 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, the low-concentration NaOH-DMSO solution can be heated to 40-60°C in a container containing water, and then the repaired master plate is immersed in the heated NaOH-DMSO solution for 10 minutes to dissolve the impurities on the graphic and non-graphic surfaces of the repaired master plate.

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

[0043] During the dissolution reaction, 5-10% ethanol by mass can also be added to the NaOH-DMSO solution according to the reaction conditions to improve the solubility of the NaOH-DMSO solution to the resin.

[0044] Further, the prepared NaOH-DMSO solution can be placed in an ultrasonic cleaning device to further enhance the solubility of the NaOH-DMSO solution by ultrasonic vibration.

[0045] In the step S3, a complete mold pressing sheet corresponding to the working plate pressed by the repaired master plate can be taken as a mold pressing sample sheet, and then the microstructure defect area is marked on the mold pressing sample sheet.

[0046] Please refer to Figure 7In the process of marking the microstructure defect point area, the intersection point of the pull gauge and the bite of the die stamping sample is used as the coordinate origin to obtain the coordinates of the microstructure defect point area. At this time, the coordinates and size of the microstructure defect point area can be obtained according to the position.

[0047] In step S4, after marking all the microstructure defect point areas on the die stamping sample, the microstructure defect point areas are enlarged with the center of each microstructure defect point area as the base point, and the enlarged microstructure defect point areas are cut and hollowed on the die stamping sample to obtain a hollowed area, thereby obtaining a hollowed mask. The shape of the hollowed area of the mask is the same as that of the microstructure defect point area, and the size is slightly larger than that of the microstructure defect point area, for example, the size of the hollowed area is 1.2 times that of the microstructure defect point area, so as to facilitate the filling of the material in the subsequent step.

[0048] In the process of attaching the mask to the pre-processed mother plate to be repaired, the hollowed mask is attached to the graphics side of the mother plate to be repaired with the bite line and the pull gauge line of the mask as the reference. In this embodiment, the graphics side of the mother plate to be repaired is upward, and the back of the mother plate to be repaired is attached to a glass plate. When the mask is attached, the hollowed mask is attached to the mother plate to be repaired with the bite and the pull gauge of the die stamping sample as the reference, so that the microstructure defect point areas on the mother plate to be repaired are all exposed to the hollowed area. The present application directly uses the bite line and the pull gauge line as the reference to align the mask and the mother plate to be repaired, so that the alignment precision is high, and the repaired area on the mother plate to be repaired does not need to be searched.

[0049] In step S4, in the process of making the repair file, the following steps are included: S41, using the bite line and the pull gauge line as the coordinates, the mask method is used to shield the graphics area that does not need to be repaired in the original photoetch file, thereby obtaining a local pattern area with the same shape and size as the hollowed area; S42, the local pattern area is enlarged to obtain a local pattern photoetch area, and the repair file is made according to the local pattern photoetch area.

[0050] In the repairing file, the coordinates of the mask opening area are obtained first, then the mask is used to cover the normal text area (i.e. the area that does not need to be repaired) in the original lithography file according to the coordinates and shape of the opening area, and the local pattern area corresponding to the opening area is retained, at this time the local pattern area and the shape and size of the opening area are the same, and then the center of the local pattern area is taken as the base point to enlarge the local pattern area to form a local pattern lithography area, for example, the local pattern lithography area is 1.2 times of the local pattern area, and the lithography text corresponding to the local pattern lithography area is obtained according to the original lithography file, so as to obtain the repaired file, which is the modified file for subsequent laser direct writing. In the embodiment, the four sides of the local pattern lithography area of the repaired file are larger than the four sides of the opening area of the mask, so that the text microstructure and the area to be repaired of the master plate are excessively smooth during the microstructure reconstruction.

[0051] Optionally, the size of the opening area is 1-8mm larger than the size of the microstructure defect point area, and the size of the local pattern lithography area is 1-8mm larger than the size of the opening area.

[0052] Preferably, referring to Figure 8 , the size of the opening area is at least 2mm extended to the four sides of the microstructure defect point area, that is, the size of the opening area is more than 4mm wider and more than 4mm longer than the size of the microstructure defect point area. The size of the local pattern lithography area is at least 2mm extended to the four sides of the opening area, so that the area to be repaired of the master plate (i.e. the microstructure defect point area) is completely exposed during deposition and laser direct writing, so that the direct writing text microstructure and the area that does not need to be repaired are excessively smooth during subsequent microstructure reconstruction.

[0053] In the process of making the mask and repairing the file, the mask is made by using the self-molded product, the four sides of the opening area of the mask are at least 2mm larger than the defect area, the lithography repair file is made according to the coordinates of the two sides of the bite and the gauge, and the original file is shielded by using the mask method to expose the lithography text of the opening area of the original file. The area of the text is at least 2mm larger than the four sides of the opening area of the mask, which realizes the microstructure text reconstruction of the microstructure defect point area and the surrounding area of the master plate, and is smoothly connected with the original microstructure text of the master plate, thereby ensuring the consistency and quality stability of the microstructure between batches.

[0054] Optionally, in step S5, the master plate to be repaired with the mask attached is placed in the material filling device to fill the material to the repair area of the master plate to be repaired, including: S51, setting a nickel target greater than or equal to 99.99% in the material filling device; S52, vacuumizing the material filling device and introducing argon into the material filling device; 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] In the process of photoetching, the embodiment adopts femtosecond short pulse laser with a very short pulse width of about 10-15 seconds, and the power density of the laser is 108-1012 W / cm2, so that the nickel element can be efficiently gasified through nonlinear absorption, and the heat affected zone is reduced. In the process of laser direct writing, inert gas (such as argon) is introduced into the photoetching equipment, and the photoetching equipment is sealed and the circulation and filtration of argon are ensured to avoid the reaction of nickel and oxygen in the air to generate NiO during the gasification process.

[0059] The application adopts the method of laser direct etching of nickel material, reduces the process of duplication, improves the efficiency of master plate repair, and also reduces the plate splicing, ensures the consistency and quality stability of the microstructure of the batch mold pressing.

[0060] Further, after the microstructure of the to-be-repaired master plate is reconstructed, the repaired master plate needs to be placed in a low-concentration NaOH-DMSO solution to dissolve the residual stains on the surface, and after cleaning, the double-sided solution and dust can be removed by negative pressure suction in a negative pressure environment. The low-concentration NaOH-DMSO solution can be the solution used in the surface pretreatment described above.

[0061] In summary, the application realizes the repairability of the microstructure master plate through the processes of flatness screening, surface pretreatment, microstructure marking, mask making, material filling, microstructure reconstruction, and surface treatment, completely avoids the waste of plate materials and the discharge of waste liquid caused by the traditional "damage and scrap", significantly reduces the production cost and lightens the environmental pressure.

[0062] The application adopts a triple alignment mechanism of mold pressing sample flaw coordinates, masks, and repair files, and the hollowed-out area and the original microstructure are highly consistent in appearance, depth, and line width, which ensures that the optical performance of the batch products pressed by the subsequent working plate is consistent, and eliminates the quality fluctuations caused by changing the plate.

[0063] At the same time, the master plate repair process skips the steps of re-splicing, full photoetching, and multiple mold pressing verification, greatly shortens the period required for re-making the master plate, reduces the number of times of starting the photoetching equipment and the consumption of nickel targets, glass substrates, and other consumables, greatly improves the efficiency of plate making and reduces the operating cost.

[0064] Moreover, the deposition thickness can be accurately set according to different microstructure depths (2-12 µm) of holographic gratings, anti-counterfeiting elements, and microlens arrays, and combined with femtosecond laser direct writing, the local reconstruction of multiple structure types can be completed on the same master plate, and the process compatibility is strong.

[0065] The repaired master plate can be directly used for making working plates again, realizing the cycle mode of "damage-repair-reuse", significantly prolonging the life cycle of the master plate, and being particularly suitable for the production of large quantities of high-value-added optical packaging materials.

[0066] It can be understood that, for those ordinary skilled in the art, equivalent replacements or changes can be made according to the technical solutions and the inventive concept of the present application, and all the changes or replacements shall fall within the protection scope of the appended claims of the present application.

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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