Microlens array and method and system for manufacturing the same

Abstract

The application discloses a micro-lens array and a preparation method and a preparation system thereof in the fields of laser micro-nano manufacturing and micro-nano optical technology, and comprises the following steps: according to a preset micro-lens array structure model, a photoetching pattern with gray information is prepared; an auxiliary pattern is inserted into the photoetching pattern; multiple exposures are carried out on photoresist according to the photoetching pattern; the auxiliary pattern is used to make the photoetched micro-lens array substructure and the edge of the photoetching pattern to be photoetched align and fit; the micro-lens array substructures obtained through the multiple exposures are spliced with each other; and the micro-lens array structure is obtained. The preparation method of the micro-lens array provided by the application inserts the auxiliary pattern, and the auxiliary pattern is used for alignment in the photoetching splicing process, so that the splicing error is reduced, the preparation process is efficient, the cost is low, and the method is suitable for large-scale batch production.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of laser micro-nano manufacturing and micro-nano optical technology, and particularly relates to a microlens array and a preparation method and a preparation system thereof. BACKGROUND

[0002] The micromirror array is composed of closely arranged periodic micro mirrors, and has been applied in many fields such as optics, communication, astronomy, biology and the like. At present, the micro mirror structure is mostly produced by machining, which has low production efficiency and high cost, and part of the technology adopts photoetching and etching, which often causes splicing errors due to alignment problems when producing large-area micromirror array. At the same time, the high reflection efficiency of the micro mirror will cause obvious glare in the local area, which needs to use various expensive coating and coating to solve. SUMMARY

[0003] The present application aims at overcoming the deficiencies in the prior art, and provides a microlens array and a preparation method and a preparation system thereof. The preparation method of the microlens array inserts an auxiliary pattern, and uses the auxiliary pattern for alignment in the photoetching splicing process, thereby reducing the splicing error, and the preparation process is efficient and low in cost, and is suitable for large-scale batch production. The microlens array prepared by the method has the advantages of large area, high precision, good reflection performance and anti-glare.

[0004] To achieve the above-mentioned purpose, the present application adopts the following technical scheme:

[0005] In a first aspect, the present application provides a preparation method of a microlens array, comprising:

[0006] According to a preset microlens array structure model, a photoetching pattern with gray scale information is made, and the photoetching pattern is a photoetching pattern of a microlens array substructure;

[0007] An auxiliary pattern is inserted in the photoetching pattern, and multiple exposures are performed on the photoresist according to the photoetching pattern. The auxiliary pattern is used to align and match the edges of the photoetched microlens array substructure and the photoetching pattern to be photoetched, so that the microlens array substructures obtained by multiple exposures are spliced with each other to obtain a microlens array structure;

[0008] The target size microlens array structure on the photoresist is transferred to the UV glue to obtain a microlens layer;

[0009] A reflection layer is prepared on the upper surface of the microlens layer;

[0010] A protection layer is prepared on the upper surface of the reflection layer;

[0011] An absorption layer is prepared on the lower surface of the microlens layer;

[0012] An anti-glare layer is prepared on the upper surface of the protective layer to obtain the microlens array.

[0013] Further, the microlens array structure model is pre-constructed, and the pre-construction includes: constructing a microlens array structure initial model, constructing a reflection model of the microlens array structure initial model, taking the maximum optical gain of reflected light as an optimization target, and optimizing the size and height of the lens to obtain a final microlens array structure model.

[0014] Further, the auxiliary pattern is inserted in the photoetching pattern, and multiple exposures are performed on the photoresist according to the photoetching pattern, the auxiliary pattern is used to align and fit the photoetched microlens array substructure and the edge of the photoetched pattern to be photoetched, the microlens array substructures obtained by multiple exposures are spliced with each other to obtain a microlens array structure, and the microlens array structure includes:

[0015] The auxiliary pattern is a cross pattern;

[0016] The first photoetching is performed on the photoresist according to the photoetching pattern to obtain an initial microlens array substructure and a reference auxiliary pattern, and the reference auxiliary pattern is the auxiliary pattern in the initial microlens array substructure;

[0017] The following steps are repeatedly performed until the spliced microlens array structure reaches a target size;

[0018] A reference coordinate system is established with the center of the reference auxiliary pattern as an origin;

[0019] Actual coordinate information of the photoetched pattern to be photoetched in the reference coordinate system is obtained, including actual horizontal coordinates of a center point of the auxiliary pattern in the photoetched pattern to be photoetched in the reference coordinate system, actual vertical coordinates of the center point of the auxiliary pattern in the photoetched pattern to be photoetched, and a rotation angle of the photoetched pattern to be photoetched relative to the initial microlens array substructure;

[0020] According to the actual coordinate information, an X-axis movement amount, a Y-axis movement amount, and a rotation angle of the center point of the auxiliary pattern in the photoetched pattern to be photoetched to the next exposure position are calculated;

[0021] The photoetched pattern to be photoetched is moved according to the X-axis movement amount, the Y-axis movement amount, and the rotation angle, and photoetching is performed after the movement is completed.

[0022] Further, the microlens array structure of the target size is spliced by n rows of m columns of microlens array substructures, and when the i-th row and the j-th column of the microlens array substructure are photoetched, the calculation method of the X-axis movement amount is:

[0023]

[0024] When When the number is even, the calculation method of the Y-axis movement amount is:

[0025]

[0026] When When the number is odd, the calculation method of the Y-axis movement amount is:

[0027]

[0028] The calculation method of the rotation angle is:

[0029]

[0030] Wherein, n≥2; m≥2; 1≤i≤n; 1≤j≤m; is the X-axis movement amount; is the Y-axis movement amount; is the rotation angle; is the actual horizontal coordinate of the center point of the auxiliary pattern in the photolithography pattern to be photolithographed; is the actual vertical coordinate of the center point of the auxiliary pattern in the photolithography pattern to be photolithographed; is the rotation angle of the photolithography pattern to be photolithographed relative to the initial microlens array substructure; is the length of the microlens array substructure along the X-axis; is the length of the microlens array substructure along the Y-axis, is the diagonal length of the microlens cross section.

[0031] Further, the photolithography pattern to be photolithographed is moved according to the X-axis movement amount, the Y-axis movement amount and the rotation angle. If the X-axis movement amount or the Y-axis movement amount is positive, the photolithography pattern to be photolithographed moves in the negative direction of the corresponding axis, and vice versa. If the rotation angle is positive, the photoresist rotates clockwise, and vice versa.

[0032] Further, the microlens array structure on the photoresist is transferred to the UV glue by UV imprinting technology. The thickness of the UV glue is 11-13µm, the curing wavelength is 365nm, and the curing time is 100-120 seconds.

[0033] Further, a protective layer is prepared on the upper surface of the reflective layer and an absorbing layer is prepared on the lower surface of the microlens layer by rolling process;

[0034] When preparing the protective layer, the rolling pressure is 4-6kg, the hot baking temperature is 85-90℃, and the time is 4-5min;

[0035] When preparing the absorbing layer, the rolling pressure is 8-10kg, the hot baking temperature is 45-50℃, and the time is 105-120min.

[0036] Further, the upper surface of the protective layer is prepared with an anti-glare layer, the anti-glare layer comprises rubber paint, curing agent and diluent, the mass ratio of the rubber paint, the curing agent and the diluent is 10: (1-1.1): (3-3.2), the thickness of the anti-glare layer is 20-30 µm, the anti-glare layer is prepared by spraying and heat baking, wherein the spraying air pressure is 0.4-0.55 Mpa, the spraying distance is 10-15 cm, the heat baking temperature is 65-70 ℃, and the time is 15-20 min.

[0037] In a second aspect, the present application provides a preparation system of a microlens array for implementing the preparation method of the microlens array.

[0038] In a third aspect, the present application provides a microlens array prepared by the preparation method of the microlens array.

[0039] Compared with the prior art, the present application has the following beneficial effects:

[0040] The preparation method of the microlens array provided by the present application inserts an auxiliary pattern, aligns the auxiliary pattern in the photoetching splicing process, reduces the splicing error, is efficient in the preparation process, is low in cost, is suitable for large-scale batch production, and the microlens array prepared by the method has the advantages of large size, high precision, good reflection performance and anti-glare performance. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 Part of the structure of the photoetching pattern provided by the embodiment of the present application is shown in the schematic diagram;

[0042] Figure 2 The alignment principle in the preparation process of the microlens array provided by the embodiment of the present application is shown in the schematic diagram;

[0043] Figure 3 The rotation in the preparation process of the microlens array provided by the embodiment of the present application is shown in the schematic diagram;

[0044] Figure 4 The structure of the microlens array provided by the embodiment of the present application is shown in the schematic diagram.

[0045] In the figure: 11, first microlens model; 12, second microlens model; 13, third microlens model; 21, first microlens array substructure; 211, first auxiliary pattern; 22, second microlens array substructure; 221, second auxiliary pattern; 23, third microlens array substructure; 231, third auxiliary pattern; 24, fourth microlens array substructure; 241, fourth auxiliary pattern; 34, absorbing layer; 31, microlens layer; 32, reflecting layer; 33, protective layer; 35, anti-glare layer. DETAILED DESCRIPTION

[0046] The application will be further described below with reference to the drawings. The following examples are only used to more clearly illustrate the technical solutions of the application, and cannot be used to limit the protection scope of the application.

[0047] Example 1

[0048] The embodiment provides a preparation method of a microlens array, comprising the following steps:

[0049] Step S1: a microlens array structure model is designed by using Lighttools software, the microlens array structure model is a close-packed hexagonal microlens array, including three kinds of lenses with different focal lengths, the heights of the three kinds of microlenses with different focal lengths are 10 µm, 8 µm and 6 µm respectively, the length of the diagonal of the cross section is 80 µm, the filling rate is 100%, a reflection model of the microlens array structure model is constructed, the optical gain of reflected light is taken as an optimization target, the size and height of the lens are optimized, and a preset microlens array structure model is obtained, and a photoetching pattern with gray information is made by using rhino drawing software. The above step S1 further comprises the following steps S11-S14:

[0050] Step S11: a microlens array structure model is established by using Solidworks and is imported into Lighttools, the scale of the model size to the actual size is 1:1;

[0051] Step S12: a light source and a detector are set on a collimating plane, the light source is an IESNA standard point light source, the luminous intensity is 1×10 6 lm, the number of light rays is 2×10 6 strips, the receiver pixel size is 20um×20um, the size is 200mm×200mm, and the collimating plane is a concave mirror with a non-spherical degree of-0.2;

[0052] Step S13: in the simulation process, in order to obtain a microlens array structure with a filling rate of 100%, a regular hexagonal microlens is selected as a basic unit. The light rays emitted by the point light source are incident on the micromirror array after collimation, and then are reflected back to the detector, the software can calculate the optical gain according to the returned light intensity, the optical gain is taken as an optimization target, the lens size and height are taken as optimization objects, and the optimized microlens array structure model can be obtained.

[0053] Step S14: the optimized microlens array pattern is drawn in Rhino software, the overall size of the microlens array pattern is 18cm×15cm, and the corresponding photoetching pattern with gray information is generated, as shown in Figure 1The partial structure diagram of the lithography pattern is shown, wherein the height of the first microlens model 11 is 10 μm, the height of the second microlens model 12 is 8 μm, and the height of the third microlens model 13 is 6 μm, which are combined to form a multi-focal microlens array structure model. The diagonal length of the cross section of the microlens model with three different focal lengths is 80 μm.

[0054] Step S2: introducing the lithography pattern with gray scale information into the 3D digital lithography system, inserting an auxiliary pattern for alignment into the lithography pattern by using the alignment function of the lithography machine, the auxiliary pattern is a cross pattern, the center of which coincides with the center of the microlens, the line length is 40 um, and the line width is 5 um; the lithography machine performs one-time exposure on the photoresist according to the lithography pattern to obtain a first microlens array structure 21. The above step S2 further includes steps S21-S24 as follows:

[0055] Step S21: spin coating photoresist on the glass base surface, the thickness of the photoresist needs to be greater than the height of the convex lens, the photoresist model is AZ4562, and step-by-step spin coating is adopted, first spin coating at a speed of 200 rpm for 10 seconds, and then spin coating at a speed of 800 rpm for 30 seconds, with an acceleration of 1000 rpm;

[0056] Step S22: placing the glass substrate with spin-coated photoresist on a flat heater to perform pre-baking, the initial temperature of pre-baking is 50℃, gradually increasing to 85℃, and the drying time at 85℃ is 45 minutes;

[0057] Step S23: introducing the lithography pattern with gray scale information into the 3D digital lithography system, adding a designed auxiliary pattern to the upper left corner of the pattern, the auxiliary pattern is a cross pattern, the line length is 40 um, the line width is 5 um, the center of the pattern coincides with the center of the microlens at the upper left corner, and the two symmetrical axes of the cross pattern coincide with the horizontal and vertical symmetrical axes of the microlens;

[0058] Step S24: after the system reads the gray scale information, the photoresist is exposed for the first time by using a 330 nm light source to obtain a first microlens array structure 21, the exposure energy is selected to be 200 MJ, the scanning speed is selected to be 100 mm / s, and the step resolution is selected to be 100 nm.

[0059] Step S3: after the first exposure, the position of the photoresist plate is adjusted and then placed into the lithography machine again, the auxiliary image is used for alignment and lithography, and the steps of adjustment and lithography are repeated multiple times, so that the microlens array substructures obtained by multiple exposures are spliced with each other to obtain a target size microlens array structure. In this embodiment, the target size microlens array structure spliced by two rows and two columns of microlens array substructures is taken as an example, and the above step S3 further includes steps S31-S36 as follows:

[0060] Step S31: import the lithography pattern to be lithographed into the lithography system, as shown in FIG. 1, the upper edge of which is complementary to the lower edge of the first microlens array substructure 21. Add a second auxiliary pattern 221 in the microlens in the upper left corner, and the addition process is synchronized with step S23; Figure 2

[0061] Step S32: adjust the lithography plate to a position convenient for lithography and reinsert it into the lithography machine. Call the alignment function of the lithography machine, find the first auxiliary pattern 211 in the upper left corner of the first microlens array substructure 21 using a high magnification system, select its center position, define it as the origin in the alignment system, and the coordinates are (0, 0). Establish a reference coordinate system, select the center of the second auxiliary pattern 221, and obtain the actual coordinate information of the lithography pattern to be lithographed, including the actual horizontal coordinate of the center point of the auxiliary pattern in the lithography pattern to be lithographed, the actual vertical coordinate of the center point of the auxiliary pattern in the lithography pattern to be lithographed, and the rotation angle of the lithography pattern to be lithographed relative to the initial microlens array substructure, as shown in FIG. 2. Figure 3

[0062] Step S33: first lithograph the microlens array substructure in the second row and the first column. The overall size of the microlens array substructure is 18 cm x 15 cm. According to the formula, the ideal position of the center of the auxiliary pattern of the microlens array substructure in the second row and the first column is (0, 15000), while the actual position is (1825, 15894) and the deflection angle is 8°. It can be calculated that = 1825, = 894, = 8°. Move the lithography pattern to be lithographed 1825 μm in the negative direction of the X axis, 894 μm in the negative direction of the Y axis, and rotate the photoresist clockwise by 8°. Adjust the coordinates of the lithography pattern to be lithographed and then expose to obtain the second microlens array substructure 22.

[0063] ​​Step S34: After completing the exposure of array 22, the microlens array substructure in the first row and second column is lithographically etched. The lithographic pattern to be etched is imported into the lithography system. A third auxiliary pattern 231 is added to the microlens in the upper left corner. The lithography plate is adjusted to a position convenient for lithography and placed back into the lithography machine. The alignment function of the lithography machine is invoked. Using the high-magnification system, the first auxiliary pattern 211 in the upper left corner of the first microlens array substructure 21 is found. Its center position is selected and defined as the origin in the alignment system with coordinates (0, 0). A reference coordinate system is established. The center of the second auxiliary pattern 221 is selected to obtain the lithography pattern to be etched. The actual coordinate information of the pattern, the actual abscissa of the center point of the auxiliary pattern in the lithographic pattern to be lithographically etched, the actual ordinate of the center point of the auxiliary pattern in the lithographic pattern to be lithographically etched, and the rotation angle of the lithographic pattern to be lithographically etched relative to the initial microlens array substructure are calculated according to the formula. The ideal position of the center of the auxiliary pattern of the microlens array substructure in the first row and second column is (18000, -40), while the actual position is (16542, -198) and the deflection angle is 5°. The coordinates of the lithographic pattern to be lithographically etched are corrected in the same way as in step S33, and then exposure is performed to obtain the third microlens array substructure 23.

[0064] Step S35: After the exposure of array 23 is completed, the microlens array substructure in the second row and second column is photolithographically etched. The photolithographic pattern to be photolithographically etched is imported into the photolithography system. A third auxiliary graphic 241 is added to the microlens in the upper left corner. The photolithography plate is adjusted to a position that is convenient for photolithography and then placed back into the photolithography machine. Then, the same process is performed to establish a reference coordinate system, obtain coordinate values, calculate displacement and rotation angle and make adjustments. Then, exposure is performed to obtain the fourth microlens array substructure 24.

[0065] Step S36: Following this pattern, expose the array in the i-th row and j-th column (n≥2; m≥2; 1≤i≤n; 1≤j≤m) until the stitched microlens array structure reaches the target size. Then, when photolithographically ...

[0066]

[0067] when When the value is even, the method for calculating the Y-axis movement is as follows:

[0068]

[0069] when When the value is odd, the method for calculating the Y-axis movement is as follows:

[0070]

[0071] The method for calculating the rotation angle is as follows:

[0072]

[0073] wherein, n≥2; m≥2; 1≤i≤n; 1≤j≤m; is the X-axis movement amount; is the Y-axis movement amount; is the rotation angle; is the actual horizontal coordinate of the center point of the auxiliary pattern in the photoetching pattern to be photoetched; is the actual vertical coordinate of the center point of the auxiliary pattern in the photoetching pattern to be photoetched; is the rotation angle of the photoetching pattern to be photoetched relative to the initial microlens array substructure; is the length of the microlens array substructure along the X-axis, in the present embodiment, is 18 cm; is the length of the microlens array substructure along the Y-axis, in the present embodiment, is 15 cm; is the diagonal length of the microlens cross section, in the present embodiment, is 80 μm.

[0074] Step S37: Develop the photoresist after exposure. The ratio of the developing solution to deionized water is 1:3, the developing time is 3 minutes, after developing, fix the photoresist with deionized water, and then dry the photoresist with compressed nitrogen.

[0075] Step S4: Transfer the microlens structure on the photoresist to the UV glue by UV imprinting, to obtain the microlens layer in the laminated structure. The above step S4 further comprises the following steps S41-S42:

[0076] Step S41: Press the PET film coated with UV glue on the photoresist plate after exposure with a roller press, and cure the UV glue after UV irradiation. Then, peel off the cured UV glue to obtain the microlens layer with structure. The rolling pressure is 4 kg, the UV glue type is UOP-1127C3-1, and the UV glue thickness is 12 μm.

[0077] Step S42: Cure the UV glue by UV irradiation, and then peel off the cured UV glue to obtain the microlens layer with structure. The UV wavelength is 365 nm, and the curing time is 120 seconds.

[0078] Step S5: Use vacuum plating equipment to make an aluminum reflective layer on the microlens layer. The above step S5 further comprises the following steps S51-S54:

[0079] Step S51: Use ultrasonic cleaning equipment to clean the surface of the microlens layer to remove dust and residual glue on the surface.

[0080] Step S52: Put the cleaned microlens layer into a vacuum plating device, with the convex lens facing up. Use a pneumatic compressor to vacuum the working cavity.

[0081] Step S53: Use an electric heating method to evaporate the aluminum target material, with a temperature of 1300 degrees.

[0082] Step S54: Control the evaporation time and plating speed to deposit about 40 nm of aluminum film on the surface of the microlens layer, forming a reflective layer.

[0083] Step S6: Prepare a protective layer on the aluminum-coated layer to improve the wear resistance and corrosion resistance of the film layer. The above step S6 further includes the following steps S61-S62:

[0084] Step S61: Put the aluminum-coated microlens layer into a coating device and roll coat the composite material 6623-03 as a transparent pre-coating layer on the surface of the aluminum film using a roller press. Let it stand for five minutes. The rolling pressure is 5 kg.

[0085] Step S62: After standing, put it into an oven for drying, and then let it stand and cool to obtain the protective layer. The drying time is 5 minutes, the drying temperature is 90 degrees, and the standing time is 5 minutes.

[0086] Step S7: Prepare an absorbing layer behind the microlens layer. The above step S7 further includes the following steps S71-S72:

[0087] Step S71: Put the PET film after the above treatment into a coating machine and coat black paint behind the microlens layer. Use a roller press to roll press with a rolling pressure of 10 kg, and then let it stand for 5 minutes.

[0088] Step S72: Send the PET film into an oven to dry and fix the black paint. The drying temperature is 50 degrees, the drying time is 105 minutes, and then cool for 10 minutes to obtain the absorbing layer.

[0089] Step S8: Prepare an anti-glare layer on the protective layer to obtain a microlens array. The above step S8 further includes the following steps S81-S82:

[0090] Step S81: Mix rubber paint, curing agent, and thinner in a ratio of 10:1:3 to obtain a glare-resistant coating.

[0091] Step S82: Use an automatic spraying device to uniformly spray the anti-glare material on the protective layer, and then let it stand for 5 minutes. The spraying air pressure is 0.4 Mpa, and the spraying distance is 10 cm.

[0092] Step S83: The PET film sprayed with the anti-glare coating is sent into an oven for drying and fixing, the drying temperature is 70 degrees, the drying time is 17 minutes, and the standing time is 10 minutes, to obtain the microlens array.

[0093] Example 2

[0094] The embodiment provides a preparation system of a microlens array, which is used for realizing the preparation method of the microlens array as described in the embodiment 1. The preparation system of the microlens array provided by the embodiment is a 3D digital lithography system, mainly including a laser dynamic focusing lens unit, which mainly comprises a Q-switched low-power laser (TEM 00 mode, Gaussian beam), an optical path unit, a control and monitoring unit, and an X-Y-Z 3D translation stage. The wavelength of the laser is 355 nm, and the maximum output power is 0.5 W. In the optical path unit, a beam expander is used to expand and collimate the laser beam, and a dynamic focusing lens unit is used to control the focus in the vertical direction. The movable lens is driven by a voice coil motor (with a motion accuracy of ±1 μm), and the motion range is 10 mm. A high-speed galvanometer scanner is used to quickly manipulate the laser beam. An F-theta lens with a focal length of 103 mm and a numerical aperture (NA) of about 0.33 is used to focus the laser beam, and the depth of field (DOF) is about 100 μm. A CCD camera is used as a monitoring unit to monitor and locate the substrate surface. A laser range finder is used to measure the relative distance between the substrate and the objective lens. The motion range of the x and y translation platforms is 200 mm, and the motion accuracy is ±1 nm. The motion accuracy of the z platform is ±3 nm, and the scanner and the F-theta lens can be vertically moved in a range of 50 mm. The entire device system is placed in a clean room with constant temperature (25±1°C) and humidity ((50±5)%). These enable the system to perform micron-level precision micro-nano machining on the sample in a small range. In order to obtain a large-area micromirror array, multiple lithography is required to increase the pattern area. However, during multiple exposures of the substrate, multiple placements of the substrate can cause damage to the coordinate system, resulting in alignment errors. Here, the microlens array is prepared by the preparation method of the microlens array as described in the embodiment 1, the centroid of the pre-designed cross-line on the sample surface is accurately positioned, and the coordinate system is reconstructed to reduce errors.

[0095] Example 3

[0096] The embodiment provides a microlens array, as shown in the drawing, which comprises, in sequence, an absorption layer 34, a microlens layer 31, a reflection layer 32, a protective layer 33, and an anti-glare layer 35. Figure 4

[0097] ​The microlens layer 31 consists of close-packed hexagonal microlenses, has a filling rate of 100%, and includes at least three microlenses with different focal lengths, the heights of the three microlenses with different focal lengths being 10 µm, 8 µm and 6 µm respectively, and the longest diagonal length of the cross section being 80 µm.

[0098] In the description of the present application, it needs to be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only used to explain the relative positional relationship, movement condition, etc. between components in a certain specific posture, and if the specific posture changes, the directional indication also changes accordingly. It is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element indicated must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", etc. are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second", etc. can be explicitly or implicitly included one or more. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0099] In the description of the present application, it needs to be understood that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0100] The embodiments of the present application are described above in combination with the drawings, but the present application is not limited to the above specific embodiments, the above specific embodiments are only illustrative, not restrictive, and those skilled in the art can make many forms under the inspiration of the present application without departing from the purpose of the present application and the scope protected by the claims, which are all within the protection of the present application.

Claims

1. A method for producing a microlens array, characterized by, The method comprises the following steps: According to the microlens array structure model, a photoetching pattern with gray information is made, and the photoetching pattern is a photoetching pattern of a microlens array substructure; An auxiliary pattern is inserted into the photoetching pattern, and multiple exposures are performed on the photoresist according to the photoetching pattern; the auxiliary pattern is used to align and match the edges of the microlens array substructure that has been photoetched and the photoetching pattern to be photoetched, the microlens array substructures obtained through multiple exposures are spliced with each other, and a microlens array structure is obtained; The microlens array structure of a target size on the photoresist is transferred to a UV glue to obtain a microlens layer; A reflective layer is prepared on the upper surface of the microlens layer; A protective layer is prepared on the upper surface of the reflective layer; An absorbing layer is prepared on the lower surface of the microlens layer; An anti-glare layer is prepared on the upper surface of the protective layer to obtain a microlens array. The step of inserting the auxiliary pattern into the photoetching pattern, performing multiple exposures on the photoresist according to the photoetching pattern, using the auxiliary pattern to align and match the edges of the microlens array substructure that has been photoetched and the photoetching pattern to be photoetched, and splicing the microlens array substructures obtained through multiple exposures with each other to obtain the microlens array structure comprises the following steps: The auxiliary pattern is a cross pattern; An initial microlens array substructure and a reference auxiliary pattern are obtained through first photoetching on the photoresist according to the photoetching pattern, and the reference auxiliary pattern is the auxiliary pattern in the initial microlens array substructure; The following steps are repeatedly performed until the spliced microlens array structure reaches a target size: A reference coordinate system is established with the center of the reference auxiliary pattern as the origin; Actual coordinate information of the photoetching pattern to be photoetched in the reference coordinate system is obtained, including the actual horizontal coordinate of the center point of the auxiliary pattern in the photoetching pattern to be photoetched, the actual vertical coordinate of the center point of the auxiliary pattern in the photoetching pattern to be photoetched, and the rotation angle of the photoetching pattern to be photoetched relative to the initial microlens array substructure; According to the actual coordinate information, the X-axis movement amount, the Y-axis movement amount, and the rotation angle of the center point of the auxiliary pattern in the photoetching pattern to be photoetched to the next exposure position are calculated; The photoetching pattern to be photoetched is moved according to the X-axis movement amount, the Y-axis movement amount, and the rotation angle, and photoetching is performed after the movement is completed.

2. The method of claim 1, wherein: The microlens array structure model is pre-constructed, and the pre-construction steps comprise: constructing an initial microlens array structure model, constructing a reflection model of the initial microlens array structure model, taking the maximum optical gain of reflected light as an optimization target, optimizing the size and height of the lens, and obtaining a final microlens array structure model.

3. The method of claim 1, wherein: The microlens array structure of the target size is spliced by n rows and m columns of microlens array substructures, and when the i-th row and the j-th column of the microlens array substructure are photoetched, the calculation method of the X-axis movement amount is: ； When When the Y axis movement amount is even, the calculation method is: ； When When Y is odd, the Y axis movement amount is calculated as follows: ； The calculation method of the rotation angle is: ； wherein n≥2; m≥2; 1≤i≤n; 1≤j≤m; is the X-axis movement amount; is the Y-axis movement amount; is the rotation angle; is the actual horizontal coordinate of the center point of the auxiliary pattern in the photolithography pattern to be photolithographed; is the actual vertical coordinate of the center point of the auxiliary pattern in the photolithography pattern to be photolithographed; is the rotation angle of the photolithography pattern to be photolithographed relative to the initial microlens array substructure; is the length of the microlens array substructure along the X-axis; is the length of the microlens array substructure along the Y-axis, is the diagonal length of the microlens cross section.

4. The method of claim 3, wherein: The method of moving the photoetching pattern to be photoetched according to the X-axis movement amount, the Y-axis movement amount, and the rotation angle comprises: If the X-axis movement amount or the Y-axis movement amount is positive, the photoetching pattern to be photoetched moves in the negative direction of the corresponding axis, and vice versa; if the rotation angle is positive, the photoresist rotates clockwise, and vice versa.

5. The method of claim 1, wherein: The microlens array structure on the photoresist is transferred to the UV glue by UV imprinting technology, the thickness of the UV glue is 11-13 µm, the curing wavelength is 365 nm, and the curing time is 100-120 seconds.

6. The method of claim 1, wherein: The protective layer is prepared on the upper surface of the reflective layer and the absorbing layer is prepared on the lower surface of the microlens layer by rolling process; The rolling pressure is 4-6 kg, the hot baking temperature is 85-90 ℃, and the time is 4-5 min when the protective layer is prepared; The rolling pressure is 8-10 kg, the hot baking temperature is 45-50 ℃, and the time is 105-120 min when the absorbing layer is prepared.

7. The method of claim 1, wherein: The anti-glare layer is prepared on the upper surface of the protective layer, the anti-glare layer includes rubber paint, curing agent and diluent, the mass ratio of the rubber paint, the curing agent and the diluent is 10: (1-1.1): (3-3.2), the thickness of the anti-glare layer is 20-30 µm, and the anti-glare layer is prepared by spraying and hot baking, wherein the spraying air pressure is 0.4-0.55 Mpa, the spraying distance is 10-15 cm, the hot baking temperature is 65-70 ℃, and the time is 15-20 min.

8. A system for producing a microlens array, characterized by comprising: The preparation method of the microlens array according to any one of claims 1-7.

9. A microlens array, characterized by The microlens array is prepared by the preparation method according to any one of claims 1-7.

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