Mold for preparing lens array based on laser positioning, preparation method of mold, lens array and preparation method of lens array

Abstract

The invention relates to the technical field of optical part processing, and discloses a mold for preparing a lens array based on laser positioning, a preparation method of the mold, the lens array and a preparation method of the lens array. The mold for preparing the lens array based on laser positioning comprises a substrate, a plurality of positioning holes and a plurality of laser positioning devices, wherein the substrate is provided with a plurality of positioning holes which are distributed in an array; and the ball is embedded in the positioning hole, and the ball is detachably connected with the positioning hole. According to the lens array mold, an assembly mode is adopted, and the mold base body can be flexibly configured according to optical design requirements, so that optical elements in various array shapes are pressed; besides, in the life cycle of the die, the ball assembly can be flexibly replaced, and the problem that the whole array die loses efficacy due to local damage of the die in the high-temperature glass pressing process is solved.

Description

Technical Field

[0001] The present application relates to the technical field of optical component processing, and particularly relates to a mold for preparing a lens array based on laser positioning, a preparation method thereof, a lens array, and a preparation method thereof. Background Art

[0002] With the development of optical systems towards integration, light weight, and miniaturization, optical components tend to be miniaturized, transitioning from discrete combinations of multiple components to array elements. Therefore, microlens arrays have emerged as a result. Common microlens surface shapes include spherical, aspherical, parabolic cylindrical, free surface, etc. Microlens arrays have the advantages of light weight, small size, flexible design, easy integration, etc., and can also achieve functions such as beam divergence, focusing, deflection, splitting, compounding, switching, coupling, and reception. They are widely used in fields such as wavefront detection, integral imaging, 3D display, optical data storage, image processing, and optical interconnection.

[0003] Currently, the processing methods for microlens arrays mainly include precision molding, glass 3D printing, mask lithography, ultra-precision microfabrication, laser direct writing, etc. Among the above processing methods, precision molding can proportionally replicate the surface shape of the mold onto the optical substrate surface at one time, thereby achieving the efficient and precise transfer of the microlens array, and has the characteristics of low cost and good consistency. Therefore, in the mass production of microlens arrays, precision molding is still the optimal choice. The efficient preparation of microlens array molds is a key factor for achieving precision molding. To ensure that the mold still maintains excellent mechanical properties and durability under high-temperature molding conditions, conventional mold materials are mainly ceramics, stainless steel, etc. However, these materials have certain limitations in terms of processing cost and efficiency, especially in the manufacturing of microlens array molds with complex morphologies.

[0004] At present, the die processing technologies for microlens arrays mainly include ultra-precision milling and turning, mask lithography, electrochemical etching, and femtosecond laser direct writing, etc. Ultra-precision milling and turning are known for their high precision and reliability. However, when processing hard and brittle materials with high hardness and high wear resistance, the tool wear is serious, it is difficult to ensure high processing precision and consistency, and the processing error is difficult to predict, resulting in low processing efficiency. Mask lithography technology forms the required structure through exposure and development processes by adjusting the light transmittance of different positions of the ultraviolet light passing through the mask. However, its processing steps are cumbersome, the efficiency is low, and the non-linear error of the mask pattern is difficult to correct, making it unsuitable for the processing of large-surface arrays. Electrochemical etching has high processing precision and is suitable for the processing of ultra-smooth surfaces, but it is not suitable for the processing of deep grooves and large-area regions. When processing hard and brittle materials, it is necessary to precisely control the etching process parameters, which is difficult and has low efficiency. Femtosecond laser direct writing technology uses a high-energy beam to bombard the material surface to achieve selective removal of the material, which can avoid thermal damage to the material. However, the processing efficiency is limited, and the microstructure morphology has strong randomness, making it unsuitable for the processing of high-precision microlens arrays. These technologies generally face problems such as the risk of die damage during processing, inaccurate microstructure array morphology, difficult to ensure array consistency, high cost, and low efficiency in the processing of microlenses from superhard materials. Therefore, the existing technologies need to be improved. Summary of the Invention

[0005] In view of the above deficiencies of the prior art, the purpose of this application is to provide a die for preparing a lens array based on laser positioning, its preparation method, a lens array, and its preparation method, aiming to solve the problem that the die is easily damaged and fails when using superhard materials to prepare a lens array.

[0006] The technical solution of this application is as follows:

[0007] In the first aspect of this application, a die for preparing a lens array based on laser positioning is provided, including: a substrate, on which a plurality of positioning holes are arranged in an array; spherical balls embedded in the positioning holes, and the spherical balls are detachably connected to the positioning holes.

[0008] Optionally, the aperture R of the positioning hole satisfies the following formula:

[0009]

[0010] where n is the safety factor, a is the maximum horizontal acceleration received by the die, ρ is the radius of the spherical ball, and g is the acceleration due to gravity;

[0011] The depth H of the positioning hole satisfies the following formula:

[0012]

[0013] Optionally, the materials of the substrate and the spherical balls respectively include at least one of silicon carbide, silicon nitride, single crystal silicon, tungsten carbide, nickel-based alloy, cobalt-based alloy, steel, stainless steel, and cast iron.

[0014] In the second aspect of the present application, a method for preparing a mold for preparing a lens array based on laser positioning according to the first aspect of the present application is provided, including the steps of: providing the substrate and the spherical balls; using laser processing on the substrate to make the positioning holes; placing the spherical balls in the positioning holes to obtain the mold for preparing the lens array based on laser positioning.

[0015] Optionally, the step of using laser to make the positioning holes on the substrate includes: using laser to draw the outer contour of the positioning holes on the substrate, and filling in the outer contour along a "return" shaped path to obtain the positioning holes, and the aperture of the outer contour is the same as that of the positioning holes.

[0016] Optionally, the output power of the laser is less than or equal to 20W, the wavelength of the laser is 532nm, and the pulse width of the laser is 10 - 200ns.

[0017] Optionally, the number of scans of the laser is positively correlated with the depth of the positioning holes.

[0018] In the third aspect of the present application, a method for preparing a lens array is provided, including the steps of: providing the mold for preparing the lens array based on laser positioning according to the first aspect of the present application and a lens array precursor, covering the lens array precursor on the side of the mold where the spherical balls are located and heating to a first preset temperature to obtain an intermediate lens array; performing a pressure treatment on the intermediate lens array under an inert atmosphere, and finally cooling to obtain the lens array.

[0019] Optionally, the range of the first preset temperature T is T g -10°C ≤ T ≤ T g +20°C, where T g is the transformation temperature of the lens array precursor; the pressure treatment step includes first pressurizing at a pressure increase rate of 0. * 01 - 0.02kN / s for 1 - 5s until the maximum pressure reaches 0.01 - 0.5kN, and maintaining the pressure for 60 - 300s.

[0020] In the fourth aspect of the present application, a lens array prepared by the method for preparing a lens array according to the third aspect of the present application is provided.

[0021] Compared with the prior art, the present application has the following advantages:

[0022] (1) The lens array mold of the present application adopts an assembled mode, which can flexibly configure the mold components according to design requirements. During its life cycle, some components can be flexibly replaced, avoiding the problem of the entire array mold failure caused by local damage of the mold during the high-temperature glass pressing process.

[0023] (2) The preparation method of the lens array mold of the present application prepares positioning holes by laser processing, with high machining accuracy, good consistency, excellent efficiency, a wide variety of optional materials, a wide range of application fields, a high degree of freedom in array design, and can achieve array designs with various shapes.

[0024] (3) The preparation method of the lens array of the present application prepares the lens array in two steps. First, the lens array mold is prepared through an assembled mode, and then the optical lens array is prepared through precision molding. The process flow is simple, the production cost is low, the preparation efficiency is high, and the engineering feasibility is good. Description of the Drawings

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments.

[0026] Figure 1 Schematic diagram of laser processing positioning holes provided by an embodiment of the present application;

[0027] Figure 2 Schematic diagram of the assembly of the lens array mold provided by an embodiment of the present application;

[0028] Figure 3 Physical diagram of the lens array mold provided by an embodiment of the present application;

[0029] Figure 4 Schematic diagram of the preparation of the lens array provided by an embodiment of the present application;

[0030] Figure 5 Schematic diagram of the geometric relationship between the lens array and the mold of the lens array provided by an embodiment of the present application;

[0031] Figure 6 Physical diagram of the lens array provided by an embodiment of the present application:

[0032] A is a regular quadrilateral lens array; B is another regular quadrilateral lens array; C is a regular hexagon lens array; D is a star-shaped array. Detailed Embodiments

[0033] To make the objectives, technical solutions, and advantages of this application clearer, the following will clearly and completely describe the technical solutions in the embodiments of this application in conjunction with the drawings and embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of this application without creative efforts belong to the scope of protection of this application. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0034] It should be noted that if there are descriptions involving "first", "second", etc. in the embodiments of this application, such "first", "second", etc. descriptions are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. Additionally, the technical solutions between various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0035] The embodiments of this application provide a mold for preparing a lens array based on laser positioning, which generally includes a substrate and a number of spherical balls. Among them, a number of positioning holes are provided on the substrate in an array distribution, the spherical balls are embedded in the positioning holes, and the spherical balls are detachably connected to the positioning holes. The number of spherical balls is the same as the number of positioning holes. It should be noted that the lens array can be a microlens array, specifically a concave microlens array.

[0036] In the processing method of the lens array, precision molding can proportionally replicate the surface shape of the mold to the surface of the lens array precursor at one time, achieving the efficient and precise transfer of the lens array, and having characteristics such as low cost and good consistency. Among them, the efficient preparation of the lens array mold is the key factor for realizing precision molding. To ensure that the mold still maintains better mechanical properties and durability under high-temperature molding conditions, conventional mold materials are mainly ceramics, stainless steel, etc. However, these materials generally face risks of processing damage, inaccurate microarray morphology, and difficulty in ensuring array consistency in the processing of superhard materials. In the mold for preparing a lens array based on laser positioning provided by this application, the spherical balls are detachably connected to the positioning holes, and thus the replacement of the spherical balls can be realized, solving the problem that the entire array mold fails due to local surface damage during multiple high-temperature glass molding processes in the preparation process of the lens array, ensuring that the surface of the prepared lens array is smooth, the features are uniform, the residual stress is small, and it has excellent focusing and imaging capabilities.

[0037] In some embodiments, to ensure sufficient surface contact between the spherical balls and the positioning holes, the aperture R of the positioning holes satisfies the following formula:

[0038]

[0039] Among them, n is the safety factor, a is the maximum horizontal acceleration suffered by the lens array mold, ρ is the radius of the spherical ball, and g is the acceleration due to gravity. Further, the depth H of the positioning hole needs to satisfy the following formula:

[0040]

[0041] In some embodiments, the materials of the substrate and the spherical ball include at least one of silicon carbide, silicon nitride, single-crystalline silicon, tungsten carbide, nickel-based alloy, cobalt-based alloy, steel, stainless steel, and cast iron.

[0042] Please refer to Figure 1 and Figure 2 , and the embodiment of the present application further provides a preparation method of a mold for preparing a lens array based on laser positioning as described above, including the steps:

[0043] S101. Provide a substrate and a spherical ball.

[0044] Among them, according to the lens array to be prepared, the size and quantity of the spherical balls are designed, and the arrangement mode of the positioning holes is pre-designed on the substrate. The diameter and depth of the positioning holes can be calculated according to the foregoing formula to ensure that the spherical balls are in full contact with the top circumference of the positioning holes, making the combined lens array mold more stable. In addition, the bottom surface of the positioning holes processed by laser is not absolutely flat and smooth. Irregular protrusions may cause gaps between the mold balls and the top circumference of the positioning holes, resulting in unstable positioning of the mold balls and affecting the consistency of the microlens array. Therefore, the depth H of the positioning holes must keep the bottom surface of the positioning holes separated from the mold balls while ensuring that the surface of the mold balls is in contact with the top circumference of the positioning holes.

[0045] In some embodiments, the materials of the substrate and the spherical ball include at least one of silicon carbide, silicon nitride, single-crystalline silicon, tungsten carbide, nickel-based alloy, cobalt-based alloy, steel, stainless steel, and cast iron. Preferably, the substrate is a silicon carbide ceramic material, which has the advantages of high hardness, high strength, high heat resistance, excellent chemical corrosion resistance, good thermal conductivity, and low thermal expansion coefficient, etc., to meet the environmental requirements of high-temperature molding. The mold ball is made of silicon nitride material, which is a ceramic material with high mechanical strength and toughness, can withstand high loads and impacts, and at the same time has excellent corrosion resistance and thermal conductivity, and its interface and optical materials do not adhere at high temperatures, meeting the requirements of high-temperature molding.

[0046] S102. Use laser to make positioning holes on the substrate.

[0047] Among them, the specific steps include: According to the depth of the contour of the positioning hole designed in S1, use a laser to first draw the outer contour of the positioning hole on the substrate, and then fill it in the outer contour along a "hui"-shaped path to obtain the positioning hole. The aperture of the outer contour is the same as that of the positioning hole. Since there may be powder residues on the substrate and the positioning hole after laser processing, in some embodiments, the substrate after laser drawing is placed in an ethanol solution and ultrasonically cleaned for 10 minutes to remove the powder residues.

[0048] In some embodiments, the laser is selected from one of femtosecond laser, nanosecond laser, and picosecond laser. In some embodiments, the output power of the laser is not greater than 20 W. For example, the power of the laser can be 1 W, 2 W, 5 W, 10 W, 15 W, or 20 W, etc. The wavelength of the laser is 532 nm, and the pulse width of the laser is 10 - 200 ns. For example, the pulse width of the laser is 10 ns, 20 ns, 50 ns, 100 ns, 120 ns, 150 ns, 180 ns, or 200 ns, etc. The number of laser scans is positively correlated with the depth of the positioning hole. After several laser scans, a positioning hole with a specific depth will be obtained on the substrate. The more the number of scans, the greater the depth H of the positioning hole. For example, when the scanning speed is set to 400 mm / s, the laser repetition frequency is set to 50 kHz, the current is set to 40 A, and the number of scans is set to 45, a positioning hole contour close to the design value can be obtained.

[0049] S103. Place the sphere in the positioning hole to obtain a mold for preparing a lens array based on laser positioning.

[0050] Please refer to Figure 4 and Figure 5 , the embodiment of the present application also provides a method for preparing a lens array, including the steps:

[0051] S201. Provide the mold for preparing a lens array based on laser positioning and a lens array precursor as described above in the embodiment of the present application. Cover the lens array precursor on the mold and heat it to a first preset temperature to obtain an intermediate lens array.

[0052] During the heating process, the viscosity of the lens array precursor decreases, enabling it to be in full contact with the mold. Among them, the lens array precursor is the raw material used to process the lens array, such as glass, polymer, etc. Specifically, the glass includes but is not limited to silicate glass (such as borosilicate glass, also known as K9 glass), quartz glass, and the polymer includes but is not limited to polymethyl methacrylate (PMMA), polycarbonate (PC). The range of the first preset temperature T is T g -10°C ≤ T ≤ T g +20°C, T gis the transformation temperature of the lens array precursor. For example, when K9 glass is used as the lens array precursor, the first preset temperature may be 590-620°C, for example, the first preset temperature may be 590°C, 600°C, 610°C or 620°C.

[0053] S202, pressurizing the lens array intermediate under an inert atmosphere (such as nitrogen), and finally cooling it to obtain a lens array.

[0054] Pressurization facilitates deformation of the lens array precursor, enabling a single-shot, proportional replication of the mold's surface shape. This process involves applying pressure at a rate of 0.01-0.02 kN / s for 1-5 seconds, reaching a maximum pressure of 0.01-0.5 kN, and maintaining pressure for 60-300 seconds. Pressure is the first-order derivative of pressure with respect to time. Controlling the pressure at 0.01-0.02 kN / s facilitates stable lens array production and higher yields. Maintaining pressure also improves the accuracy of proportional replication of the mold's surface shape.

[0055] The cooling process is divided into a slow cooling phase and a rapid cooling phase. The slow cooling phase slowly lowers the temperature to 400-500°C to ensure low residual stress. Rapid cooling can lead to excessive residual stress in the lens array or even damage it. The rapid cooling phase allows the temperature to be quickly lowered to 50-120°C, facilitating subsequent removal of the mold and lens array.

[0056] Cooling the lens array and mold by combining slow cooling and rapid cooling can not only avoid uneven cooling that causes large stress to remain in the lens array, affecting the optical performance and mechanical strength of the lens array, but also improve efficiency and reduce preparation time.

[0057] An embodiment of the present application also provides a lens array prepared using the lens array preparation method described above.

[0058] The following is further described with reference to specific embodiments.

[0059] Example 1

[0060] (1) SiC ceramic material is selected as the substrate and sphere of the mold for preparing the lens array based on laser positioning. The size of the substrate is 20mm×20mm×6mm. The nanosecond laser processing system is focused according to the height size and the focus position is adjusted to the upper surface of the substrate. The designed positioning hole array (such as Figure 1The drawing process is as follows: First, draw the outer contour of a single positioning hole with a radius of R. Then, set the appropriate spacing and infill amount. Following a U-shaped path, evenly fill the entire circular outer contour. Here, the radius R is 715μm and the infill spacing is 15μm. According to the formula, the depth H of the positioning hole must be greater than 0.015mm. The established positioning hole model is then arrayed according to the regular quadrilateral arrangement to obtain the positioning hole array model.

[0061] The positioning holes were machined using a laser output power of 20W, a wavelength of 532nm, a pulse width of 100ns, a laser scanning speed of 400mm / s, a laser repetition rate of 50kHz, a current of 40A, and a scan count of 45. The substrate was then ultrasonically cleaned in an ethanol solution for 10 minutes to produce a substrate with positioning holes arranged in an array. Finally, SiN ceramic balls (round balls) with a diameter of 2mm were placed in each positioning hole, resulting in a mold for preparing a lens array based on laser positioning.

[0062] (2) K9 glass is selected as the material of the lens array, and the spherical array on the mold is copied to the surface of the K9 glass by precision molding. The mold and K9 glass are heated to 600 ° C and maintained for 240 seconds. In a nitrogen atmosphere, the pressure is increased at a pressure of 0.014 kN / s to a final pressure of 0.29 kN, and the pressure is maintained for 240 seconds. The pressure is released, and the temperature is slowly lowered to 450 ° C. Then, the glass element is rapidly cooled to 100 ° C. After the shape of the glass element is determined, the mold is separated from the glass element to obtain a lens array. Figure 6 As shown in A.

[0063] Example 2

[0064] (1) SiC ceramic material is selected as the substrate and sphere of the mold for preparing the lens array based on laser positioning. The size of the substrate is 20mm×6mm×6mm. The nanosecond laser processing system is focused according to the height size and the focus position is adjusted to the upper surface of the substrate. The designed positioning hole array (such as Figure 1 The drawing process is as follows: First, draw the outer contour of a single positioning hole with a radius of R. Then, set the appropriate spacing and infill amount. Following a U-shaped path, evenly fill the entire circular outer contour. Here, the radius R is 715μm and the infill spacing is 0.015mm. According to the formula, the depth H of the positioning hole must be greater than 300μm. The established positioning hole model is then arrayed according to a regular hexagonal arrangement to create a positioning hole array model.

[0065] The laser output power was set to 20W, the light source wavelength to 532nm, the pulse width to 100ns, the laser scanning speed to 400mm / s, the laser repetition rate to 50kHz, the current to 40A, and the number of scans to 45 to obtain the outer contour of the positioning holes. The number of laser scans was then adjusted to complete the drawing of the positioning holes. The substrate was then ultrasonically cleaned in an ethanol solution for 10 minutes to produce a substrate with positioning holes distributed in an array. Finally, SiC ceramic balls (round balls) were placed in each positioning hole to obtain a mold for preparing a lens array based on laser positioning.

[0066] (2) K9 glass is selected as the material of the lens array, and the structured array on the mold is copied to the K9 glass surface by precision molding. The mold and K9 glass are heated to 590°C and maintained for 180 seconds. In a nitrogen atmosphere, the pressure is increased at a rate of 0.02 kN / s to a final pressure of 0.32 kN, and the pressure is maintained for 60 seconds. The pressure is released, and the temperature is slowly lowered to 400°C. The glass element is then rapidly cooled to 50°C. After the shape of the glass element is determined, the mold is separated from the glass element to obtain a lens array. Figure 6 As shown in B.

[0067] Example 3

[0068] (1) SiC ceramic material is selected as the substrate and sphere of the mold for preparing the lens array based on laser positioning. The size of the substrate is 20mm×20mm×8mm. The nanosecond laser processing system is focused according to the height size and the focus position is adjusted to the upper surface of the substrate. The designed positioning hole array (such as Figure 1 The drawing process is as follows: First, draw the outer contour of a single positioning hole with a radius of R. Then, set the appropriate spacing and infill amount. Following a U-shaped path, evenly fill the entire circular outer contour. Here, the radius R is 1075 μm, and the infill spacing is 15 μm. According to the formula, the depth H of the positioning hole must be greater than 454 μm. The established positioning hole model is then arrayed according to a regular hexagonal arrangement to create a positioning hole array model.

[0069] The laser output power used was 20W, the wavelength of the light source was 532nm, the pulse width was 100ns, the laser scanning speed was set to 400mm / s, the laser repetition rate was set to 50kHz, the current was set to 40A, and the number of scans was set to 78 to complete the processing of the positioning holes. The substrate was then ultrasonically cleaned in an ethanol solution for 10 minutes to produce a substrate with positioning holes distributed in an array. Finally, SiC ceramic balls (round balls) with a diameter of 3mm were placed in each positioning hole to obtain a mold for preparing a lens array based on laser positioning.

[0070] (2) PMMA is selected as the material of the lens array, and the structured array on the mold is replicated onto the PMMA surface by means of precision molding. The mold and PMMA are heated to 140 °C and maintained for 180 s. The pressure is applied at a rate of 0.01 kN / s until the final pressure reaches 0.3 kN, and the pressure is maintained for 60 s. The pressure is released, the temperature is slowly lowered to 100 °C, and then the glass component is rapidly cooled to 40 °C. After the shape of the PMMA optical component is determined, the mold is separated from the PMMA, and the lens array can be obtained, as Figure 6 shown in C of

[0071] Example 4

[0072] The lens array is obtained by the same method as in Example 3, as Figure 6 shown in D of

[0073] In summary, the lens array mold of the present application adopts an assembly mode, can flexibly configure the mold components according to the design requirements, can flexibly replace some components during the life cycle, and avoids the problem of the failure of the entire array mold caused by local damage of the mold during the high-temperature glass pressing process. The preparation method of the lens array mold prepares positioning holes by laser processing, has high processing precision, excellent efficiency, a wide variety of optional material types, a wide application field, a high degree of freedom in array design, and can realize diverse array designs. The preparation method of the lens array prepares the lens array in two steps. First, the lens array mold is prepared by the assembly mode, and then the lens array is prepared by precision molding. The process flow is simple, the production cost is low, the preparation efficiency is high, and the engineering feasibility is good.

[0074] It should be understood that the application of the present application is not limited to the above examples. For those of ordinary skill in the art, improvements or transformations can be made according to the above description, and all such improvements and transformations should fall within the protection scope of the appended claims of the present application.

Claims

1. A mold for preparing a lens array based on laser positioning, characterized in that, Comprising: A base, on which a plurality of positioning holes distributed in an array are provided; Spherical balls embedded in the positioning holes, and the spherical balls are detachably connected to the positioning holes.

2. The mold for preparing a lens array based on laser positioning according to claim 1, wherein The aperture R of the positioning hole satisfies the following formula: Wherein, n is the safety factor, a is the maximum horizontal acceleration received by the mold, ρ is the radius of the spherical ball, and g is the acceleration of gravity; The depth H of the positioning hole satisfies the following formula:

3. The mold for preparing a lens array based on laser positioning according to claim 1, characterized in that, The materials of the base and the spherical balls respectively include at least one of silicon carbide, silicon nitride, single crystal silicon, tungsten carbide, nickel-based alloy, cobalt-based alloy, steel, stainless steel, and cast iron.

4. A method for preparing a mold for fabricating a lens array based on laser positioning according to any one of claims 1 to 3, characterized in that, Including steps: Providing the base and the spherical balls; Using laser processing on the base to obtain the positioning holes; Placing the spherical balls in the positioning holes to obtain the mold for preparing the lens array based on laser positioning.

5. The preparation method according to claim 4, wherein, The step of using laser to obtain the positioning holes on the base includes: Using laser to draw the outer contour of the positioning hole on the base, and filling it in the outer contour according to a "return" shaped path to obtain the positioning hole, and the aperture of the outer contour is the same as the aperture of the positioning hole.

6. The preparation method according to claim 5, characterized in that, The output power of the laser is less than or equal to 20W, the wavelength of the laser is 532nm, and the pulse width of the laser is 10 - 200ns.

7. The preparation method according to claim 5, characterized in that, The scanning times of the laser are positively correlated with the depth of the positioning hole.

8. A method for preparing a lens array, characterized in that, Including steps: Providing the mold for preparing the lens array based on laser positioning according to any one of claims 1 to 3 and a lens array precursor, covering the lens array precursor on the surface where the spherical balls are located on the mold and heating it to a first preset temperature to obtain an intermediate lens array; Performing a pressure treatment on the intermediate lens array under an inert atmosphere, and finally cooling to obtain the lens array.

9. The method for preparing the lens array according to claim 8, wherein The range of the first preset temperature T is T g -10 ≤ T ≤ T g +20, where T g is the conversion temperature of the lens array precursor; The step of the pressure treatment includes first pressurizing at a pressure increase rate of 0.01 - 0.02 kN / s for 1 - 5 s until the maximum pressure is 0.01 - 0.5 kN, and maintaining the pressure for 60 - 300 s.

10. A lens array prepared by using the method for preparing a lens array according to claim 8 or 9.

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