Cylindrical grating mother substrate preparation method and system, slit mask, cylindrical grating preparation method

Abstract

The application provides a cylindrical lens grating mother plate preparation method and system, a slit mask, and a cylindrical lens grating preparation method. The mother plate preparation method comprises the following steps: moving a mask relative to a photoresist layer along a first direction; wherein the photoresist layer is formed on a substrate, and the mask comprises at least one light-transmitting slit extending along a second direction, and the second direction intersects the first direction; in the moving process, light of a light source is used to expose the photoresist layer through the light-transmitting slit; wherein the photoresist layer receives exposure energy distribution corresponding to a target cylindrical lens profile in the first direction; and after development, the photoresist layer after exposure forms a cylindrical lens grating mother plate with the target cylindrical lens profile. Thus, the same set of slit masks can meet the production requirements of various different specifications of cylindrical lens gratings.

Description

Technical Field

[0001] This application relates to the field of semiconductor fabrication technology, and in particular to a method and system for fabricating a lenticular grating master, a slit mask, and a method for fabricating a lenticular grating. Background Technology

[0002] In related technologies, when fabricating lenticular gratings, a matching mask must be customized based on the grating parameters, resulting in the inability to use masks uniformly. When different lenticular gratings need to be fabricated, new masks must be designed and manufactured, which not only increases production costs but also extends the production cycle. Furthermore, the complex fabrication process of traditional masks, with extremely high precision requirements, further limits the fabrication of different lenticular gratings. Especially for lenticular gratings with special grating parameters or non-standard periods, the difficulty and cost of customizing masks increase significantly, making it difficult to meet the needs of small-batch, multi-variety production. Summary of the Invention

[0003] This application proposes a method and system for preparing a cylindrical lens grating master, a slit mask, and a method for preparing a cylindrical lens grating, aiming to solve the problems in related technologies where mask preparation is complex and masks cannot be used uniformly when dealing with cylindrical lens gratings with different grating parameters.

[0004] The first aspect of this application provides a method for preparing a lenticular grating master, comprising: The photomask moves relative to the photoresist layer along a first direction; wherein the photoresist layer is formed on a substrate, and the photomask includes at least one light-transmitting slit extending along a second direction, the second direction intersecting the first direction; During the movement, light from the light source exposes the photoresist layer through the light-transmitting slit; wherein the distribution of exposure energy received by the photoresist layer in the first direction corresponds to the morphology of the target cylindrical lens; After exposure, the photoresist layer is developed to form a cylindrical grating master with the target cylindrical morphology.

[0005] Optionally, the exposure energy distribution varies non-uniformly in the first direction to form a curved cylindrical lens.

[0006] Optionally, the exposure energy distribution is controlled in any of the following ways: When the photomask moves at a constant speed relative to the photoresist layer, the emitted light power of the light source varies non-uniformly along the moving path; or, When the light output power of the light source is constant, the mask is controlled to move at a variable speed relative to the photoresist layer along the moving path.

[0007] Optionally, on the photoresist layer, the exposure energy received at any exposure position and the development depth at the exposure position satisfy a logarithmic function relationship, wherein the development depth at the exposure position is related to the grating parameters of the target cylindrical lens morphology.

[0008] Optionally, when the photoresist layer is a positive photoresist and the target cylindrical lens morphology is a groove profile, the exposure energy received by the photoresist layer in the first direction is distributed such that the central region is higher than the two side regions; or When the photoresist layer is a positive photoresist and the target cylindrical lens has a convex profile, the exposure energy received by the photoresist layer in the first direction is distributed such that the central region is lower than the two side regions.

[0009] Optionally, when the mask includes only one light-transmitting slit, the exposure energy distribution varies periodically, and the period of the periodic variation is determined according to the grating period of the target cylindrical lens morphology.

[0010] Optionally, when the mask includes multiple light-transmitting slits, the relative displacement of any of the light-transmitting slits in the first direction is determined according to the grating period of the target cylindrical lens morphology.

[0011] Optionally, the number of light-transmitting slits is determined based on the number of cylindrical lenses contained in the cylindrical lens grating corresponding to the target cylindrical lens morphology.

[0012] Optionally, the second direction is determined based on the tilt angle of the cylindrical lens contained in the cylindrical lens grating corresponding to the target cylindrical lens morphology.

[0013] The second aspect of this application provides a method for preparing a lenticular lens grating, comprising: transferring a lenticular lens grating master plate formed using the lenticular lens grating master plate preparation method proposed in any embodiment of this application to form a lenticular lens grating soft template; The lenticular lens grating is obtained by embossing based on the lenticular lens grating soft template.

[0014] The third aspect of this application provides a slit mask, which includes at least one light-transmitting slit, and is applied in the preparation method of the cylindrical grating master described in any embodiment of this application.

[0015] Optionally, there is one light-transmitting slit.

[0016] Optionally, there are multiple light-transmitting slits, and the spacing between adjacent light-transmitting slits is determined according to the grating period of the target cylindrical lens morphology.

[0017] Optionally, the number of light-transmitting slits is determined based on the number of cylindrical lenses contained in the cylindrical lens grating corresponding to the target cylindrical lens morphology.

[0018] Optionally, the extension direction of the light-transmitting slit is the tilt direction of the cylindrical lens contained in the cylindrical lens grating corresponding to the target cylindrical lens shape.

[0019] Optionally, the width of the light-transmitting slit is 1-2 micrometers.

[0020] A fourth aspect of this application provides a lenticular lens grating master fabrication system, comprising: a controller and a slit mask as described in any embodiment of this application; the controller is used in the lenticular lens grating master fabrication method described in any embodiment of this application.

[0021] According to embodiments of this application, a method and system for fabricating a lenticular lens grating master, a slit mask, and a method for fabricating a lenticular lens grating are proposed. The master fabrication method includes: moving the mask relative to a photoresist layer along a first direction; wherein the photoresist layer is formed on a substrate, and the mask includes at least one light-transmitting slit extending along a second direction, which intersects the first direction; during the movement, light from a light source exposes the photoresist layer through the light-transmitting slit; wherein the exposure energy distribution received by the photoresist layer in the first direction corresponds to the target lenticular lens morphology; and after development, the exposed photoresist layer forms a lenticular lens grating master with the target lenticular lens morphology. Therefore, during fabrication, only the exposure energy distribution of the cylindrical region in the first direction needs to be controlled by software according to the current lenticular lens grating parameters, without requiring any physical modification or replacement of the slit mask itself. This approach allows the same slit mask to meet the production needs of various cylindrical gratings of different specifications, greatly reducing the mask design and manufacturing costs and time required due to changes in grating parameters. It significantly improves the flexibility and economy of cylindrical grating fabrication, bringing great convenience to research and development and production. Attached Figure Description

[0022] Figure 1 This is a flowchart of the method for preparing a cylindrical lens grating master according to an embodiment of this application; Figure 2 This is a schematic diagram showing the positional relationship between the adhesive plate and the slit mask in the method for preparing the cylindrical lens grating master according to the embodiments of this application; Figure 3 This is a schematic diagram of the slit mask proposed in the embodiments of this application; Figure 4 This is a schematic diagram of the method for preparing a cylindrical lens grating master according to an embodiment of this application; Figure 5 This is a schematic diagram of another method for preparing a cylindrical lens grating master according to an embodiment of this application; Figure 6 This is a structural diagram of the cylindrical lens grating master preparation system proposed in the embodiments of this application.

[0023] Reference numerals: 100, slit mask; 101, slit; 200, adhesive plate; 201, substrate; 202, adhesive layer; 2021, cylindrical area; 300, workpiece stage; 400, exposure mechanism; 500, developing mechanism; 600, controller; 700, adhesive coating mechanism. Detailed Implementation

[0024] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the present application and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the present application are shown in the drawings, not the entire structure. Various modifications and variations can be made to the present application without departing from its spirit or scope, which will be apparent to those skilled in the art. Therefore, the present application is intended to cover modifications and variations of the present application that fall within the scope of the technical solutions claimed in the corresponding claims and their equivalents. It should be noted that the implementation methods provided in the embodiments of the present application can be combined with each other without contradiction.

[0025] Figure 1 This is a flowchart of the method for preparing a cylindrical lens grating master according to an embodiment of this application. Figure 2 This is a schematic diagram showing the positional relationship between the adhesive plate and the slit mask in the method for preparing the cylindrical lens grating master according to the embodiments of this application. Figure 3 This is a schematic diagram of the slit mask plate proposed in an embodiment of this application. Figures 1 to 3 As shown, the master template preparation method includes: S101, the photomask moves relative to the photoresist layer along a first direction; wherein the photoresist layer is formed on the substrate, and the photomask includes at least one light-transmitting slit extending along a second direction, the second direction intersecting the first direction.

[0026] The substrate 201 can be made of materials with good flatness and chemical stability, such as glass or silicon wafers, to ensure the accuracy of subsequent coating and exposure processes. The photoresist layer 202 can be formed on the surface of the substrate 201 using appropriate coating mechanisms such as spin coating, spray coating, or roll coating. The photomask 100 is used to expose the photoresist layer 202 to form an exposure pattern on the photoresist layer 202 that is identical to the light-transmitting slit 101 of the photomask 100.

[0027] In one embodiment, the light-transmitting slit 101 extends in the second direction Y, and moves in the first direction X. The second direction Y and the first direction X intersect, and can be perpendicular or not, depending on the actual shape of the substrate 201 and the extension direction of the cylindrical lens of the target cylindrical lens grating.

[0028] In practical applications, the second direction Y is usually set to be perpendicular to the first direction X to facilitate control of the movement path and the arrangement of subsequent cylindrical lens structures. For example, when the cylindrical lens of the target cylindrical lens grating extends vertically, the extension direction of the light-transmitting slit 101 (the second direction Y) can be set to the vertical direction, while the movement direction (the first direction X) is set to the horizontal direction. In this way, by moving the light-transmitting slit 101 in the horizontal direction, a cylindrical lens structure extending vertically can be formed on the photoresist layer 202. The photoresist layer 202 and the substrate 201 form a photoresist plate 200. The movement method can be to control the workpiece stage to move the photoresist plate 200 with the photoresist layer 202 in the first direction X, while the slit mask 100 remains fixed; or the slit mask 100 can be controlled to move in the first direction X, while the workpiece stage and the photoresist plate 200 remain fixed. By precisely controlling the movement speed and displacement, it is ensured that the light-transmitting slit 101 can move stably and uniformly on the photoresist plate 200 according to the preset trajectory. This embodiment and subsequent schemes are illustrated using the example of mutually perpendicular structures.

[0029] S102, during the movement, the light from the light source exposes the photoresist layer through the light-transmitting slit; wherein, the distribution of exposure energy received by the photoresist layer in the first direction corresponds to the morphology of the target cylindrical lens.

[0030] In other words, the exposure energy received at different positions of the photoresist layer 202 along the moving direction (first direction X) is pre-set according to the preset cross-sectional profile of the target cylindrical lens. For example, if the target cylindrical lens is convex, the cross-sectional profile used to fabricate the convex cylindrical lens is concave. The exposure energy is lower where the curvature is greater and higher where the curvature is less. Before exposing the photoresist layer 202, the correspondence between the exposure energy distribution and the target cylindrical lens morphology can be simulated, calibrated, or calculated using optical software and pre-stored in the controller. In practice, the controller can adjust the output power of the exposure mechanism in real time, or adjust the moving speed of the workpiece stage or mask during the movement, to change the exposure energy at different positions in the first direction X to match the morphological requirements of the target cylindrical lens.

[0031] S103, after exposure, the photoresist layer is developed to form a cylindrical grating master with the target cylindrical lens morphology.

[0032] After exposure, the photoresist layer 202 undergoes a change in solubility according to a preset energy distribution. After selective dissolution by the developer, the exposed and unexposed areas will leave structures with corresponding height differences based on the energy difference, ultimately forming a lenticular grating master with a cross-sectional profile that perfectly matches the target morphology. Throughout the entire fabrication process, lenticular grating masters with different curvatures, pitches, and heights can be fabricated simply by adjusting the exposure energy distribution during the movement. There is no need to adjust the slit mask parameters or replace the mask, significantly lowering the barrier to entry for fabricating customized lenticular grating masters.

[0033] Therefore, this embodiment uses a slit mask combined with energy control for exposure. Only the exposure energy distribution during the exposure process needs to be adjusted to adapt to different cylindrical lens morphology requirements. There is no need to replace the mask. One set of masks can meet the production of cylindrical lens gratings of different specifications, which greatly reduces the cost and cycle of research and development and production.

[0034] Optionally, the exposure energy distribution is non-uniform in the first direction to form a curved cylindrical lens.

[0035] Because the width D of the light-transmitting slit 101 is very narrow, when the light-transmitting slit 101 moves the photoresist plate 200 in the first direction X, each position of the cylindrical region 2021 to which the light-transmitting slit 101 moves can be understood as the position of the discretized cross-sectional profile of each curved cylindrical lens. Simultaneously with the movement of the light-transmitting slit 101, the exposure mechanism is controlled to illuminate the light-transmitting slit 101, resulting in different exposure energies when the light-transmitting slit 101 moves to different positions on the photoresist layer 202. For example, each discretized cross-sectional profile of the curved cylindrical lens has a first position to an nth position. When the light-transmitting slit 101 moves to the first position, the exposure energy received at the first position is E1; when the light-transmitting slit 101 moves to the second position, the exposure energy received at the second position is E2; and the exposure energy received at the nth position is En, where n is a positive integer. E1 to En exhibit a non-uniform distribution, which is related to the surface profile of the cylindrical lens in the formed target cylindrical lens grating and the properties of the photoresist layer 202. In actual operation, the non-uniform distribution of exposure energy at each position can be obtained in advance through calibration, or a calculation formula can be formed based on the surface profile of the cylindrical lens, the properties of the photoresist layer 202, the exposure parameters of the exposure mechanism, and the moving position of the light-transmitting slit 101. Then, a controller is used for control.

[0036] The curved cylindrical lens can be either a convex or concave curved cylindrical lens. For a convex curved cylindrical lens, the master mold for fabricating the convex curved cylindrical lens is concave. The exposure energy of the photoresist layer 202 at the center of the exposure area in the first direction X is higher than that at the edge. After development, more photoresist in the center area is dissolved, resulting in a concave structure where the center is lower than the edge. If the target cylindrical lens is a concave curved cylindrical lens, and the master mold for fabricating the convex curved cylindrical lens is convex, the exposure energy of the photoresist layer 202 at the center of the exposure area in the first direction X is lower than that at the edge. After development, less photoresist in the center area is dissolved, resulting in a convex structure where the center is higher than the edge. Thus, it can flexibly adapt to the fabrication needs of different types of curved cylindrical lenses.

[0037] As a result, the exposure energy distribution is non-uniform in the first direction X, causing the exposure energy received by the photoresist layer 202 to be non-uniform. Thus, after exposure and development, the photoresist layer 202 can form a non-uniform convex or concave structure.

[0038] Optionally, the exposure energy distribution is controlled in one of the following ways: when the mask moves at a constant speed relative to the photoresist layer, the light output power of the light source varies non-uniformly along the moving path; or, when the light output power of the light source is constant, the mask is controlled to move at a variable speed relative to the photoresist layer along the moving path.

[0039] Since the exposure energy received at position i (1≤i≤n) is related to the exposure power and exposure time of the exposure mechanism, when the light-transmitting slit 101 moves to each position and stays for the same time, that is, the exposure time is the same, the exposure power can be adjusted to be different. When the light-transmitting slit 101 moves to each position and stays for different times, that is, the exposure time is different, the exposure power can be the same.

[0040] In this embodiment, the exposure mechanism can be an ultraviolet light source, a laser light source, or other light sources with a specific wavelength, which can provide stable and adjustable optical power output.

[0041] When the photomask 100 moves relative to the photoresist layer 202, it can either keep the slit photomask 100 stationary while controlling the movement of the photoresist layer 200, or keep the photoresist layer 200 stationary while controlling the movement of the slit photomask 100. The following explanation uses the example of keeping the slit photomask 100 stationary while controlling the movement of the photoresist layer 200.

[0042] When the rubber plate 200 is fixed on the workpiece stage, and the controller controls the workpiece stage to drive the rubber plate 200 to move at a constant speed v along the first direction X, the slit mask 100 remains stationary at this time. During the process in which the light-transmitting slit 101 moves over the cylindrical region 2021, the exposure light power P of the exposure mechanism is dynamically adjusted according to the real-time position of the light-transmitting slit 101 within the cylindrical region 2021 (that is, the moving distance x of the rubber plate 200). Assume that the length of the cylindrical region 2021 in the first direction X is L, the movement starts from the position x=0 and ends at the position x=L. According to the contour requirements of the target lenticular lens, the exposure light power is preset as P0 at the position x=0, as Pa at the position x=a (0<a<L), and as PL at the position x=L, wherein the values of P0, Pa, and PL form a continuous or discrete non-uniform light power distribution curve. The controller pre-stores the relation curve between the exposure position and the exposure light power, as well as the moving speed v of the workpiece stage, so the controller can control the movement of the workpiece stage, then accurately acquire the current position x of the light-transmitting slit 101 within the cylindrical region 2021 by reading the displacement feedback signal of the workpiece stage, and then adjust the output light power of the exposure mechanism in real time according to the preset light power distribution curve, so that the exposure energy received at different positions on the cylindrical region 2021 (exposure energy E = light power P × exposure time t; since the moving speed v is constant, the exposure time t=dL / dv at each position is the same, so E(x)=P(x)×t) presents a non-uniform variation that matches the contour of the target lenticular lens. This method of realizing the non-uniform distribution of exposure energy by adjusting the exposure light power has high control precision, fast response speed, and simple control strategy.

[0043] In another embodiment, the exposure power P of the exposure mechanism remains constant. When either the slit mask 100 or the adhesive plate 200 (e.g., the adhesive plate 200 is fixed to the workpiece stage, and the stage is controlled by a controller to move it) moves at a non-uniform speed in the first direction X, the moving speed v(x) of the light-transmitting slit 101 at different positions within the cylindrical region 2021 will change, resulting in different exposure times t = dL / dv at each position. Therefore, the exposure energy E(x) = P × t(x). By pre-setting the moving speed curve v(x) of the cylindrical region 2021 in the first direction X, when the moving speed is slow, the exposure time t increases, and the exposure energy E increases; when the moving speed is fast, the exposure time t decreases, and the exposure energy E decreases. For example, if a target cylindrical lens requires higher exposure energy at a certain position in the first direction X, the workpiece stage is controlled to move at a lower speed at that position; if lower exposure energy is required, it moves at a higher speed. The controller can also achieve a non-uniform variation of exposure energy received by the cylindrical region 2021 in the first direction X by precisely controlling the movement speed of the workpiece stage as its position changes. By transforming the requirement for non-uniform distribution of exposure energy into control of mechanical motion speed, it may be easier to integrate and work collaboratively with the motion control system of existing equipment in certain specific process scenarios.

[0044] In both embodiments described above, whether adjusting the exposure power or controlling the moving speed (dwell time), the core objective is to achieve a precise non-uniform distribution of exposure energy in the cylindrical region 2021 along the first direction X, thereby ensuring that a cylindrical lens shape meeting the requirements can be obtained after development. In practical applications, the choice or combination of these methods can be flexibly selected based on specific equipment conditions, process requirements, and cost budgets.

[0045] Optionally, on the photoresist layer, the exposure energy received at any exposure position and the development depth at the exposure position satisfy a logarithmic function relationship, wherein the development depth at the exposure position is related to the grating parameters of the target cylindrical lens morphology.

[0046] Specifically, the target grating parameters of the cylindrical lens grating master include the target sagitta h of the cylindrical lens, the target radius of curvature R, and the grating period T (which is the width of the cylindrical region 2021 in the X direction).

[0047] In this embodiment, T=L, and multiple cylindrical lenses are periodically arranged along the X direction to form a cylindrical lens array. Within each cylindrical region 2021, the cylindrical lens to be formed includes a lens base and a lens surface. The midpoint of the lens base on the cross-section of the cylindrical lens is x, where x=L / 2. The curve formed by the lens surface on the cross-section of the cylindrical lens is approximately a circular arc, and its profile function can be expressed as follows: Where z(x) is the height of the cylindrical lens surface at the corresponding exposure position x relative to the reference plane. The above profile satisfies: z(0) = z(L) = 0, z(L / 2) = h, which means that the height is zero at the edge of the period and the maximum sagittal height h is reached at the center of the period, forming a cylindrical profile with a predetermined curvature radius R.

[0048] Considering the motion relationship x=x(t) of the rubber sheet 200, the target contour is represented in the time domain as: .

[0049] For the exposure mechanism, within the process range, the exposure energy E and the development depth z satisfy a logarithmic relationship: E = A - Blnz; where A and B are empirical constants related to the photoresist type and process conditions. A and B can be obtained through least squares fitting.

[0050] Specifically, A linear model is obtained. By using least squares fitting, we can obtain the calculation expressions for A and B: ; ; j is the number of samples participating in the fitting, i≤j, and all are positive integers.

[0051] During the exposure process, the exposure power of the exposure mechanism is P(t), and the cumulative exposure energy within the time interval [0, t] is E(t) = P(t) × t. Since E = A - Blnz, then P(t) × t = E(t) = A - Blnz(t). Thus, the relationship between the exposure power P, exposure time t, exposure energy E(t), and target contour z(t) is established. In the actual control logic, the moving speed of the film plate 200 or the slit mask 100 can be kept constant, and the optical power P(t) of the exposure mechanism can be controlled to change with time to adjust the exposure energy distribution of the cylindrical region 2021. Alternatively, x(t) can be solved, and the derivative of x(t) can be obtained to obtain the relationship of v(t). The exposure power P(t) of the exposure mechanism can be kept constant, thereby controlling the moving speed v(t) of the film plate 200 to change.

[0052] Optionally, when the photoresist layer is a positive photoresist and the target cylindrical lens morphology is a groove profile, the exposure energy received by the photoresist layer in the first direction is distributed such that the central region is higher than the two side regions; or When the photoresist layer is a positive photoresist and the target cylindrical lens has a convex profile, the exposure energy received by the photoresist layer in the first direction is distributed such that the central region is lower than the two side regions.

[0053] Figure 4 This is a schematic diagram of the method for fabricating a cylindrical lens grating master according to an embodiment of this application. Figure 4 As shown, when the exposure energy received by the cylindrical region 2021 on the positive photoresist substrate in the first direction X exhibits a distribution characteristic of first increasing and then decreasing, according to the characteristics of positive photoresist, the area with higher exposure energy will have more photoresist dissolved during development, while the area with lower exposure energy will have less dissolved. Therefore, within the cylindrical region 2021, the location with the highest exposure energy (e.g., the center of the region) will form the deepest depression due to the most photoresist dissolution. As the region moves towards both sides, the exposure energy gradually decreases, and the amount of photoresist dissolved also decreases accordingly, resulting in a shallower depression. Until at the edge of the cylindrical region 2021, the exposure energy is minimal, and the photoresist is hardly dissolved or dissolved in very small amounts, thus forming a relatively convex edge. In this way, after development, the surface of the positive photoresist substrate will exhibit a concave cylindrical lens structure with a concave center and gradually convex sides, i.e., a concave cylindrical lens grating master. This method of precisely shaping the concave cylindrical lens profile by controlling the distribution of exposure energy can effectively ensure the optical performance and dimensional accuracy of the master copy, laying a good foundation for subsequent grating replication processes.

[0054] Figure 5 This is a schematic diagram of another method for preparing a cylindrical lens grating master according to an embodiment of this application. Figure 5 As shown, when the exposure energy received by the cylindrical region 2021 on the positive photoresist substrate in the first direction X exhibits a distribution characteristic of first decreasing and then increasing, according to the development characteristics of the positive photoresist, the area with lower exposure energy has less photoresist dissolved during development, while the area with higher exposure energy has more dissolved photoresist. Therefore, within the cylindrical region 2021, the location with the lowest exposure energy (e.g., the center of the region) has the least dissolved photoresist, leaving the thickest photoresist layer, thus forming the highest convexity. As the region moves towards both sides, the exposure energy gradually increases, and the amount of photoresist dissolved also increases accordingly, with the remaining photoresist layer gradually thinning until the edge of the cylindrical region 2021, where the exposure energy is the highest, the amount of photoresist dissolved is the most, the photoresist layer is the thinnest, or even completely dissolved, forming a relatively concave edge. Thus, after development, the surface of the positive photoresist substrate will exhibit a convex cylindrical lens structure with a convex center and gradually concave sides, i.e., a convex cylindrical lens grating master. This method of obtaining the convex cylindrical lens profile by reverse designing the exposure energy distribution can also precisely control key parameters such as the curvature and sagitta of the master plate, meeting the diverse needs of different optical systems for cylindrical lens gratings.

[0055] Optionally, when the mask includes only one light-transmitting slit, the exposure energy distribution varies periodically, and the period of the periodic variation is determined according to the grating period of the target cylindrical lens morphology.

[0056] If there is only one light-transmitting slit 101, when forming the concave cylindrical lens master, the light-transmitting slit 101 can be controlled to first move and expose a cylindrical region 2021. During the movement, the exposure power or moving speed can be adjusted according to the exposure energy requirements of the concave cylindrical lens (e.g., increasing first and then decreasing). After the exposure of the cylindrical region is completed, the slit mask 100 or the film plate 200 can be moved to allow the light-transmitting slit 101 to continue moving to the next cylindrical region 2021. The exposure mechanism is then activated again and the moving exposure is performed according to the preset exposure energy distribution. This cycle is repeated to achieve the movement of the light-transmitting slit 101 on the film plate 200 to the cylindrical region 2021, ultimately forming a periodically arranged concave cylindrical lens structure on the film plate 200.

[0057] When forming the convex cylindrical lens master, as the light-transmitting slit 101 moves the cylindrical area 2021, the exposure energy requirement is first reduced and then increased (by adjusting the light power or moving speed). This process is repeated, thereby completing the fabrication of the convex cylindrical lens grating master on the entire film plate 200 through the movement of a single light-transmitting slit 101.

[0058] In this embodiment, a light-transmitting slit 101 can move continuously along the first direction X, and the exposure power or exposure time of the exposure mechanism varies with the grating period of the target cylindrical lens morphology.

[0059] Optionally, when the photomask includes multiple light-transmitting slits, the relative displacement of any light-transmitting slit in the first direction is determined according to the grating period of the target cylindrical lens morphology.

[0060] If there are multiple light-transmitting slits 101, please refer to the following: Figure 4 and Figure 5 Multiple light-transmitting slits 101 are uniformly arranged along the first direction X on the slit mask 100 according to the grating period T. When the slit mask 100 or the film plate 200 is moved, all the light-transmitting slits 101 move synchronously. At this time, each light-transmitting slit 101 corresponds to a cylindrical region 2021 on the film plate 200. During the movement, the exposure mechanism provides synchronously varying exposure light power to each light-transmitting slit 101 according to the exposure energy requirements of different cylindrical lenses, or achieves the exposure energy distribution within each cylindrical region 2021 by controlling the change in the overall moving speed. This method of synchronous movement of multiple slits can significantly improve exposure efficiency, completing the exposure of multiple cylindrical regions 2021 at one time, and is particularly suitable for large-scale, high-efficiency production of cylindrical lens grating masters.

[0061] Therefore, if there are N target cylindrical lens gratings, the mask of one light-transmitting slit 101 can move along the first direction in X steps for N grating periods T, and the exposure energy distribution of the exposure mechanism changes periodically N times. The masks of M light-transmitting slits 101 can move along the first direction in X steps a times, where a is equal to N / M rounded down, and the exposure energy distribution of the exposure mechanism changes periodically a times.

[0062] Optionally, the number of light-transmitting slits is determined based on the number of cylindrical lenses contained in the cylindrical lens grating corresponding to the target cylindrical lens morphology.

[0063] In other words, if there are N target cylindrical lens gratings, N light-transmitting slits 101 can be set in the mask 100. Thus, all cylindrical regions 2021 can be moved in one step along the first direction (X steps). This means the entire exposure process can be completed in a single movement, eliminating the need for multiple step-by-step movements. This maximizes the efficiency of the multi-slit design, significantly shortens the production cycle, reduces positioning errors during fabrication, and improves the structural accuracy of the final cylindrical lens grating master. Simultaneously, this full-number slit design simplifies the production process, reduces the operational complexity caused by repetitive positioning, and is more suitable for the needs of industrial mass production.

[0064] Optionally, the second direction is determined based on the tilt angle of the cylindrical lens contained in the cylindrical lens grating corresponding to the target cylindrical lens morphology.

[0065] When the cylindrical lenses need to be designed with an inclined arrangement, the light-transmitting slit extension direction of the slit mask, i.e. the second direction Y, can be tilted at a corresponding angle (less than 90° or greater than 90°) to the first direction X. When moving the slit mask or film plate, the shape requirements of the inclined cylindrical lenses can be directly matched without the need for additional rotation adjustment of the film plate. This retains the precision advantage of moving exposure and can flexibly adapt to the fabrication needs of cylindrical lens gratings with different tilt angles. It can realize the production of diversified cylindrical lens grating master plates without complex modification of the existing equipment structure.

[0066] This application also proposes a method for preparing a lenticular lens grating, comprising: using a lenticular lens grating master prepared by any embodiment of this application, a lenticular lens grating master is formed by transfer printing to form a lenticular lens grating soft template; and a lenticular lens grating is obtained by imprinting based on the lenticular lens grating soft template.

[0067] Specifically, the process of transferring a lenticular lens grating soft template typically involves coating the surface of the lenticular lens grating master with a material possessing good elasticity and replication properties, such as silicone or PDMS (polydimethylsiloxane). After coating, a curing process is performed to ensure that the material adheres tightly to the lenticular structure on the master surface and forms a stable shape. Subsequently, the cured material is peeled off from the master, and the resulting soft template replicates the precise concave or convex lenticular structure on the master surface, becoming an intermediate medium for subsequent imprinting processes. The use of soft templates effectively protects the expensive original master, preventing wear or damage during frequent imprinting, and also facilitates large-area, continuous imprinting production. The imprinting process based on lenticular lens grating soft templates involves contacting the soft template with the surface of the substrate to be processed (such as plastic film, glass, etc.), and applying appropriate pressure and temperature (determined according to the substrate material and the characteristics of the imprinting adhesive) to transfer the lenticular structure pattern on the soft template into the imprinting adhesive layer on the substrate surface. After imprinting, the imprinted adhesive layer is cured and set through steps such as UV curing or thermal curing. Finally, the flexible template is removed, and a lenticular lens grating with the same structure as the master template is formed on the substrate surface. This method, which combines transfer and imprinting processes based on master templates and flexible templates, features high production efficiency, low cost, high pattern replication accuracy, and suitability for large-scale industrial production. It can meet the mass production needs of high-performance lenticular lens gratings in multiple fields such as display, imaging, anti-counterfeiting, and optical communication.

[0068] Continue to refer to Figure 2 and Figure 3 This application also proposes a slit mask 100, which is applied in the preparation method of the cylindrical lens grating master in any embodiment of this application.

[0069] Optionally, there is only one light-transmitting slit 101. If there is only one light-transmitting slit 101, when forming the concave cylindrical lens master, the light-transmitting slit 101 can be controlled to first move and expose a cylindrical region 2021. During the movement, the exposure power or moving speed can be adjusted according to the exposure energy requirements of the concave cylindrical lens (e.g., increasing first and then decreasing). After the exposure of the cylindrical region is completed, the slit mask 100 or the film plate 200 can be moved to allow the light-transmitting slit 101 to continue moving to the next cylindrical region 2021. The exposure mechanism is then activated again and the moving exposure is performed according to the preset exposure energy distribution. This cycle is repeated to achieve the movement of the light-transmitting slit 101 on the film plate 200 to the cylindrical region 2021, ultimately forming a periodically arranged concave cylindrical lens structure on the film plate 200.

[0070] When forming the convex cylindrical lens master, as the light-transmitting slit 101 moves the cylindrical area 2021, the exposure energy requirement is first reduced and then increased (by adjusting the light power or moving speed). This process is repeated, thereby completing the fabrication of the convex cylindrical lens grating master on the entire film plate 200 through the movement of a single light-transmitting slit 101.

[0071] In this embodiment, a light-transmitting slit 101 can continuously move along the first direction X, and the exposure power or exposure time of the exposure mechanism varies according to the grating period of the target cylindrical lens morphology. It is simple, practical, and widely applicable, and can be used for different types of adhesive sheets 200.

[0072] Optionally, there are multiple light-transmitting slits 101, and the spacing between adjacent light-transmitting slits is determined according to the grating period of the target cylindrical lens morphology.

[0073] Multiple light-transmitting slits 101 are uniformly arranged along the first direction X on the slit mask 100 according to the grating period T. When the slit mask 100 or the film plate 200 is moved, all the light-transmitting slits 101 move synchronously. At this time, each light-transmitting slit 101 corresponds to a cylindrical region 2021 on the film plate 200. During the movement, the exposure mechanism provides synchronously varying exposure light power to each light-transmitting slit 101 according to the exposure energy requirements of different cylindrical lenses, or achieves the exposure energy distribution within each cylindrical region 2021 by controlling the change in the overall moving speed. This method of synchronous movement of multiple slits can significantly improve exposure efficiency, completing the exposure of multiple cylindrical regions 2021 at once, and is particularly suitable for large-scale, high-efficiency production of cylindrical lens grating masters.

[0074] Optionally, the number of light-transmitting slits is determined based on the number of cylindrical lenses contained in the cylindrical lens grating corresponding to the target cylindrical lens morphology.

[0075] In other words, if there are N target cylindrical lens gratings, N light-transmitting slits 101 can be set in the mask 100. Thus, all cylindrical regions 2021 can be moved in one step along the first direction. This means the entire exposure process can be completed in a single movement, eliminating the need for multiple step-by-step movements. This maximizes the efficiency of the multi-slit design, significantly shortens the production cycle, reduces positioning errors during fabrication, and improves the structural accuracy of the final cylindrical lens grating master. Simultaneously, this full-number slit design simplifies the production process, reduces the operational complexity caused by repetitive positioning, and is more suitable for the needs of industrial mass production.

[0076] Optionally, the extension direction of the light-transmitting slit is the tilt direction of the cylindrical lens contained in the cylindrical lens grating corresponding to the topography of the target cylindrical lens.

[0077] When the cylindrical lenses need to be designed with an inclined arrangement, the light-transmitting slit extension direction of the slit mask, i.e. the second direction Y, can be tilted at a corresponding angle (less than 90° or greater than 90°) to the first direction X. When moving the slit mask or film plate, the shape requirements of the inclined cylindrical lenses can be directly matched without the need for additional rotation adjustment of the film plate. This retains the precision advantage of moving exposure and can flexibly adapt to the fabrication needs of cylindrical lens gratings with different tilt angles. It can realize the production of diversified cylindrical lens grating master plates without complex modification of the existing equipment structure.

[0078] Optionally, the width of the light-transmitting slit 101 is 1-2 micrometers. The number, arrangement, and dimensional parameters (such as width and length) of the light-transmitting slits 101 can be flexibly designed and adjusted according to the period of the target cylindrical lens grating master, the size of the cylindrical lens, and the fabrication process requirements. For example, when fabricating a cylindrical lens grating master with a specific period T, the center-to-center spacing of multiple light-transmitting slits 101 on the slit mask 100 can be set to be equal to the period T, ensuring that each light-transmitting slit 101 accurately corresponds to and exposes a cylindrical region 2021 during movement. The slit width is related to the mask fabrication process and diffraction effects; too small a width will cause diffraction, while too large a width will result in insufficient precision. In other words, the width of the light-transmitting slit 101 affects the size of the exposure spot and the uniformity of energy distribution. A light-transmitting slit 101 in the range of 1-2 micrometers helps to obtain a finer cylindrical lens profile edge and enables the discrete continuous representation of the cylindrical region 2021. Furthermore, the length of the light-transmitting slit 101 should at least cover the dimension of the cylindrical region 2021 on the photomask 200 in the second direction Y (i.e., the direction perpendicular to the movement direction) to ensure that the entire cylindrical region 2021 can be exposed in that direction with a single movement. That is, the slit length is equal to the size of the target product, and the number of slits on the entire photomask is determined by the size of the target product: (number of slits - 1) * grating period = width of the target product.

[0079] This allows the same slit mask to meet the production needs of various cylindrical gratings of different specifications. Consequently, the cylindrical grating master fabrication method of this application has greater adaptability and flexibility, and can meet the fabrication needs of cylindrical grating masters of different specifications and application scenarios. Since the fabrication process only requires controlling the exposure energy distribution of the cylindrical region in the first direction X according to the grating parameters of the current cylindrical grating using software, no physical modification or replacement of the slit mask itself is required, which greatly reduces the mask design and fabrication costs and time cycle caused by changes in grating parameters.

[0080] Figure 6 This is a structural diagram of the lenticular lens grating master fabrication system proposed in an embodiment of this application. It includes: a controller 600 and a slit mask 100 as described in any embodiment of this application; the controller 600 is used to execute the lenticular lens grating master fabrication method described in any embodiment of this application. In one specific embodiment, as... Figure 6 As shown, the cylindrical lens grating master preparation system may also include: a workpiece stage 300, an exposure mechanism 400, a developing mechanism 500, and a coating mechanism 700. The workpiece stage 300 is used to carry the substrate 201; the controller 600 is electrically connected to the workpiece stage 300, the exposure mechanism 400, the coating mechanism 700 and the developing mechanism 500 respectively. The coating mechanism 700 is used to coat photoresist on the substrate surface to form a uniform photoresist plate 200; the exposure mechanism 400 is used to provide an exposure light source and expose the cylindrical area on the photoresist plate through the slit mask 100, and its exposure light power can be dynamically adjusted according to the preset exposure energy distribution; the developing mechanism 500 is used to develop the exposed photoresist plate, dissolving the photoresist in the exposed area (positive photoresist), thereby forming the required cylindrical lens structure on the surface of the photoresist plate 200; the controller 600, as the core of the system, is responsible for coordinating the entire preparation process, including controlling the movement of the workpiece stage 300 or the slit mask 100 to achieve precise movement of the slit on the photoresist plate 200, setting and adjusting key preparation parameters such as the exposure light power and moving speed of the exposure mechanism according to the target cylindrical lens structure parameters, and controlling the working status of the coating mechanism 700 and the developing mechanism 500 to ensure that each step is carried out in an orderly manner according to the preset process sequence and parameter requirements.

[0081] In this application, the cylindrical region 2021 is the region where a cylindrical mirror structure is to be formed.

[0082] In summary, this application provides a method and system for fabricating a lenticular lens grating master, a slit mask, and a method for fabricating a lenticular lens grating. The master fabrication method includes: moving the mask relative to the photoresist layer along a first direction; wherein the photoresist layer is formed on a substrate, and the mask includes at least one light-transmitting slit extending along a second direction, which intersects the first direction; during the movement, light from a light source exposes the photoresist layer through the light-transmitting slit; wherein the exposure energy distribution received by the photoresist layer in the first direction corresponds to the target lenticular lens morphology; and after development, the exposed photoresist layer forms a lenticular lens grating master with the target lenticular lens morphology. Therefore, during fabrication, only the exposure energy distribution of the cylindrical region in the first direction needs to be controlled by software according to the current grating parameters of the lenticular lens grating, without requiring any physical modification or replacement of the slit mask itself. This approach allows the same slit mask to meet the production needs of various cylindrical gratings of different specifications, greatly reducing the mask design and manufacturing costs and time required due to changes in grating parameters. It significantly improves the flexibility and economy of cylindrical grating fabrication, bringing great convenience to research and development and production.

[0083] The specific embodiments described above do not constitute a limitation on the scope of protection of this application. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A method for preparing a lenticular lens grating master, characterized in that, The method includes: The photomask moves relative to the photoresist layer along a first direction; wherein the photoresist layer is formed on a substrate, and the photomask includes at least one light-transmitting slit extending along a second direction, the second direction intersecting the first direction; During the movement, light from the light source exposes the photoresist layer through the light-transmitting slit; wherein the distribution of exposure energy received by the photoresist layer in the first direction corresponds to the morphology of the target cylindrical lens; After exposure, the photoresist layer is developed to form a cylindrical grating master with the target cylindrical morphology.

2. The method for preparing a lenticular lens grating master according to claim 1, characterized in that, The exposure energy distribution is non-uniform in the first direction to form a curved cylindrical lens.

3. The method for preparing a lenticular grating master according to claim 2, characterized in that, The exposure energy distribution is controlled in any of the following ways: When the photomask moves at a constant speed relative to the photoresist layer, the emitted light power of the light source varies non-uniformly along the moving path; or, When the light output power of the light source is constant, the mask is controlled to move at a variable speed relative to the photoresist layer along the moving path.

4. The method for preparing a cylindrical lens grating master according to any one of claims 1-3, characterized in that, On the photoresist layer, the exposure energy received at any exposure position and the development depth at the exposure position satisfy a logarithmic function relationship, wherein the development depth at the exposure position is related to the grating parameters of the target cylindrical lens morphology.

5. The method for preparing a lenticular grating master according to claim 1, characterized in that, When the photoresist layer is a positive photoresist and the target cylindrical lens has a groove profile, the exposure energy received by the photoresist layer in the first direction is distributed such that the central region is higher than the two side regions. or When the photoresist layer is a positive photoresist and the target cylindrical lens has a convex profile, the exposure energy received by the photoresist layer in the first direction is distributed such that the central region is lower than the two side regions.

6. The method for preparing a lenticular grating master according to claim 1, characterized in that, When the photomask includes only one light-transmitting slit, the exposure energy distribution exhibits a periodic variation, the period of which is determined based on the grating period of the target cylindrical lens morphology.

7. The method for preparing a lenticular lens grating master according to claim 1, characterized in that, When the mask includes multiple light-transmitting slits, the relative displacement of any of the light-transmitting slits in a first direction is determined according to the grating period of the target cylindrical lens morphology.

8. The method for preparing a cylindrical lens grating master according to claim 7, characterized in that, The number of light-transmitting slits is determined based on the number of cylindrical lenses contained in the cylindrical lens grating corresponding to the target cylindrical lens morphology.

9. The method for preparing a lenticular lens grating master according to claim 7, characterized in that, The second direction is determined based on the tilt angle of the cylindrical lens contained in the cylindrical lens grating corresponding to the target cylindrical lens morphology.

10. A method for fabricating a cylindrical lens grating, characterized in that, include: Using the lenticular lens grating master prepared by any one of the lenticular lens grating master preparation methods as described in claims 1-9, a lenticular lens grating soft template is transferred to form it; The lenticular lens grating is obtained by embossing based on the lenticular lens grating soft template.

11. A slit mask, characterized in that, It includes at least one light-transmitting slit and is used in the preparation method of the cylindrical lens grating master as described in any one of claims 1-9.

12. The slit mask according to claim 11, characterized in that, There may be one or more light-transmitting slits, and the spacing between adjacent light-transmitting slits is determined according to the grating period of the target cylindrical lens morphology.

13. A lenticular lens grating master preparation system, characterized in that, include: The controller and the slit mask as described in claim 11 or 12; The controller is used to execute the method for preparing a cylindrical lens grating master as described in any one of claims 1-9.

Images