Method and System for Preparing a Spherical Array of Microlenses

Abstract

The present application provides a method and a system for preparing a spherical micro-lens array. The method includes: spin-coating a first photoresist on the front side of a silicon wafer; performing exposure and development on the first photoresist to obtain a plurality of local photoresist pillar arrays, each local photoresist pillar array including a plurality of local photoresist pillars; etching the front side according to the plurality of local photoresist pillar arrays to obtain a plurality of local silicon pillar arrays, each local silicon pillar array including a plurality of local silicon pillars; coating a second photoresist on the front side; using a photolithography process and an overlay process to cover the second photoresist on one side of the plurality of local silicon pillar arrays close to the front side to obtain a micro-lens photoresist pillar array, the micro-lens photoresist pillar array including a plurality of micro-lens photoresist pillars, each micro-lens photoresist pillar covering a plurality of local silicon pillars of the corresponding local silicon pillar array; heating the micro-lens photoresist pillar array to soften and form the plurality of micro-lens photoresist pillars into a spherical micro-lens array. By controlling the formed local silicon pillar arrays, the present application can control the size of the contact angle of the spherical micro-lens array.

Description

Technical Field

[0001] This application relates to the technical field of optical elements, and particularly to a method and system for preparing a spherical micro-lens array. Background Art

[0002] A spherical micro-lens array is a micro-optical focusing element that has wide applications in fields such as optical communication, integral imaging, fiber coupling, and light field display technology. There are various methods for preparing a spherical micro-lens array, such as micro-jet printing method, femtosecond laser direct writing method, etc., and the hot melting method of photoresist based on lithography technology is the most commonly used. The method of traditional lithography technology is to directly coat a layer of photoresist on the surface of a silicon wafer, and then lithograph a columnar photoresist array and melt it to fabricate a spherical micro-lens array. In order to increase the contact angle of the spherical micro-lens, the hydrophobic property of the silicon wafer surface is usually changed, including selecting to coat other materials or overall surface structuring to improve the hydrophobic ability of the surface. However, the overall modification of the silicon wafer surface is affected by factors such as material uniformity and processing conditions, and it is difficult to control the size of the contact angle. Summary of the Invention

[0003] This application provides a method and system for preparing a spherical micro-lens array. While increasing the contact angle of the spherical micro-lens by forming a micro-lens glue column array on a local silicon column array, the size of the contact angle can also be controlled.

[0004] In a first aspect, an embodiment of this application provides a method for preparing a spherical micro-lens array. The method for preparing a spherical micro-lens array includes: spin-coating a first photoresist on the front surface of a silicon wafer; performing exposure and development on the first photoresist to obtain a plurality of local glue column arrays, each local glue column array including a plurality of local glue columns; etching the front surface according to the plurality of local glue column arrays to obtain a plurality of local silicon column arrays, each local silicon column array including a plurality of local silicon columns, each local silicon column array corresponding to a local glue column array, and the plurality of local silicon columns corresponding one-to-one to the plurality of local glue columns of the corresponding local glue column array; coating a second photoresist on the front surface; using a lithography process and a registration process to cover the second photoresist on one side of the plurality of local silicon column arrays close to the front surface to obtain a micro-lens glue column array, the micro-lens glue column array including a plurality of micro-lens glue columns, each micro-lens glue column covering the plurality of local silicon columns of the corresponding local silicon column array; heating the micro-lens glue column array to soften and form the plurality of micro-lens glue columns into a spherical micro-lens array, the spherical micro-lens array including a plurality of spherical micro-lenses, each spherical micro-lens corresponding to a local silicon column array and being supported by the plurality of local silicon columns of the corresponding local silicon column array.

[0005] Second aspect, an embodiment of the present application provides a system for preparing a spherical micro-lens array. The system for preparing a spherical micro-lens array includes a photoresist coating device, an exposure and development device, a first photoresist processing device, a second photoresist processing device, and a heating device. The photoresist coating device is configured to spin-coat a first photoresist on the front surface of a silicon wafer. The exposure and development device is configured to perform exposure and development on the first photoresist to obtain a plurality of local glue column arrays, each local glue column array including a plurality of local glue columns. The first photoresist processing device is configured to etch the front surface according to the plurality of local glue column arrays to obtain a plurality of local silicon column arrays, each local silicon column array including a plurality of local silicon columns. Each local silicon column array corresponds to a local glue column array, and the plurality of local silicon columns correspond one-to-one to the plurality of local glue columns of the corresponding local glue column array. The photoresist coating device is further configured to coat a second photoresist on the front surface. The second photoresist processing device is configured to use a photolithography process and an overlay process to cover the second photoresist on one side of the plurality of local silicon column arrays close to the front surface to obtain a micro-lens glue column array. The micro-lens glue column array includes a plurality of micro-lens glue columns, and each micro-lens glue column covers a plurality of local silicon columns of the corresponding local silicon column array. The heating device is configured to heat the micro-lens glue column array so that the plurality of micro-lens glue columns are softened and formed into a spherical micro-lens array. The spherical micro-lens array includes a plurality of spherical micro-lenses. Each spherical micro-lens corresponds to a local silicon column array and is supported by a plurality of local silicon columns of the corresponding local silicon column array.

[0006] The above method and system for preparing a spherical micro-lens array pre-obtain a first photoresist corresponding to a variety of preset arrays by exposing and developing the first photoresist spin-coated on the front surface of the silicon wafer, and etch the front surface according to the variety of preset arrays by an ICP etching process to obtain corresponding local silicon column arrays, so that when coating the second photoresist, the second photoresist can be supported by the local silicon column arrays to obtain a micro-lens glue column array, and then a spherical micro-lens array is formed when heating the micro-lens glue column array. At the same time, the formed local silicon column arrays can also be controlled by controlling the photolithography process and the overlay process, and further the size of the contact angle can be controlled. Description of the Drawings

[0007] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0008] Figure 1 It is the first flowchart of the method for preparing a spherical micro-lens array provided by the embodiment of the present application.

[0009] Figure 2 It is a flowchart of the sub-steps of step S102 provided by the embodiment of the present application.

[0010] Figure 3 It is the second flowchart of the method for preparing a spherical micro-lens array provided by the embodiment of the present application.

[0011] Figure 4 It is a flowchart of the sub-steps of step S106 provided by the embodiment of the present application.

[0012] Figure 5 It is a schematic structural diagram of the system for preparing a spherical micro-lens array provided by the embodiment of the present application.

[0013] Figure 6 It is the first schematic diagram of the application scenario of the method for preparing a spherical micro-lens array provided by the embodiment of the present application.

[0014] Figure 7 It is the second schematic diagram of the application scenario of the method for preparing a spherical micro-lens array provided by the embodiment of the present application.

[0015] Figure 8 It is the third schematic diagram of the application scenario of the method for preparing a spherical micro-lens array provided by the embodiment of the present application.

[0016] Figure 9 It is the fourth schematic diagram of the application scenario of the method for preparing a spherical micro-lens array provided by the embodiment of the present application.

[0017] Figure 10 It is a schematic diagram of the technical effect of the method for preparing a spherical micro-lens array provided by the embodiment of the present application.

[0018] The realization of the purpose of the present application, functional features and advantages will be further described with reference to the embodiments and the accompanying drawings. Detailed implementation manners

[0019] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0020] In the description and claims of this application and the above-mentioned drawings, terms such as "first", "second", "third", "fourth", etc. (if any) are used to distinguish similar planning objects and do not necessarily describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances. In other words, the described embodiments are implemented in an order other than that illustrated or described herein. In addition, the terms "comprising" and "having" and any variations thereof may further include other elements. For example, a process, method, system, product, or device comprising a series of steps or units need not be limited to only those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products, or devices.

[0021] It should be noted that in this application, the descriptions involving "first", "second", etc. are only for descriptive purposes and should not be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more 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.

[0022] Please refer to Figure 1 , which is the first flowchart of the method for preparing a micro-lens spherical array provided by an embodiment of this application. This application provides a method for preparing a micro-lens spherical array. The method for preparing a micro-lens spherical array includes steps S101 - S106.

[0023] Step S101, spin-coat a first photoresist on the front side of the silicon wafer.

[0024] In step S101, the silicon wafer 1 can be used to carry the micro-lens spherical array. The first photoresist 2 can be a positive photoresist. In this application, the first photoresist 2 is coated on the front side of the silicon wafer 1 by spin-coating, which not only makes the first photoresist 2 evenly coated on the silicon wafer 1 but also can controllably set the thickness of the first photoresist 2 by controlling the spin-coating process. Exemplarily, the first photoresist 2 is AZ1515 photoresist. The thickness of the first photoresist 2 can be 0.2 - 5 microns.

[0025] Step S102, expose and develop the first photoresist to obtain a plurality of local photoresist column arrays.

[0026] In step S102, each local glue column array 21 includes a plurality of local glue columns 211. The plurality of local glue column arrays 21 can be the same or different local glue column arrays. Since the first photoresist 2 is a positive photoresist, it is sensitive to light and prone to photoreaction. Therefore, when the first photoresist 2 is irradiated in different ways, the first photoresist 2 can correspondingly represent different patterns through the plurality of local glue column arrays 21.

[0027] Please refer to Figure 2 , which is a flowchart of the sub-steps of step S102 provided by the embodiment of the present application. Obtaining a plurality of local glue column arrays by exposing and developing the first photoresist includes steps S1021 - S1023.

[0028] Step S1021, respectively determine the exposed area and the non-exposed area of the first photoresist according to a variety of preset arrays.

[0029] In step S1021, the variety of preset arrays are used to characterize a variety of expected patterns of the first photoresist 2, thereby affecting the shape of the subsequent micro-lens spherical surface 5. The exposed area and the non-exposed area are determined according to the size and shape of the micro-lens spherical surface 5. The distribution of the exposed area and the non-exposed area in the area where the first photoresist 2 is located is also affected by the angle formed between the first photoresist 2 and the equipment used for exposure processing and development processing. Different preset arrays have different exposed areas. Each preset array corresponds to a local glue column array 21. In the present application, the non-exposed area is determined according to a variety of expected patterns corresponding to a variety of preset arrays.

[0030] Step S1022, irradiate the first photoresist according to the exposed area and the non-exposed area.

[0031] In step S1022, the first photoresist 2 in the exposed area undergoes a photoreaction. At this time, the solubility of the first photoresist 2 in the exposed area changes, resulting in a difference in solubility from the first photoresist 2 in the exposed area. Furthermore, according to the solubility of the exposed area and the non-exposed area, the required first photoresist 2 can be selectively retained. To ensure the uniformity when irradiating the first photoresist 2, the first photoresist 2 is dried before irradiating the first photoresist 2.

[0032] Step S1023, develop the first photoresist after the irradiation treatment to project the variety of preset arrays onto the first photoresist, so that the plurality of local glue columns of each local glue column array are arranged on the front according to the corresponding preset array to obtain a plurality of local glue column arrays.

[0033] In step S1023, since the first photoresist 2 is a positive photoresist, the development process can be to remove the first photoresist 2 in the exposed area and retain the first photoresist 2 in the unexposed area. Since the unexposed area is determined according to multiple expected patterns corresponding to multiple preset arrays, the multiple expected patterns will be projected onto the first photoresist 2 after the development process, that is, the multiple preset arrays are correspondingly projected onto the first photoresist 2.

[0034] Step S103, etching the front side according to multiple local glue column arrays to obtain multiple local silicon column arrays.

[0035] In step S103, multiple local silicon column arrays 3 are arranged at intervals on the front side of the silicon wafer 1. Each local silicon column array 3 includes multiple local silicon columns 31 arranged at intervals. The multiple local silicon columns 31 cooperate together to support the spherical surface 5 of the microlens. Grooves are formed between each local silicon column 31 and the adjacent local silicon column 31, and the grooves are recessed from the front side of the silicon wafer 1 in a direction away from the front side. Each local silicon column array 3 corresponds to a local glue column array 21, and the multiple local silicon columns 31 correspond one-to-one to the multiple local glue columns 211 of the corresponding local glue column array 21.

[0036] Step S104, coating a second photoresist on the front side.

[0037] In step S104, the second photoresist 4 is used to form the spherical surface 5 of the microlens. The first photoresist 2 and the second photoresist 4 are different positive photoresists. Exemplarily, the second photoresist 4 can be AZ4620 photoresist or other series of positive photoresists.

[0038] Step S105, using a lithography process and an overlay process to cover the second photoresist on one side of the multiple local silicon column arrays close to the front side to obtain a microlens glue column array.

[0039] In step S105, the microlens glue column array includes multiple microlens glue columns. Each microlens glue column covers the multiple local silicon columns 31 of the corresponding local silicon column array 3. Among them, the height of the local silicon column 31 is 10 - 600 microns. In this application, the height of the microlens glue column is greater than the height of the local silicon column 31, so that the microlens glue column can completely cover the corresponding local silicon column array 3 when it is melted and softened by heat, for the multiple local silicon columns 31 to support the subsequent formed spherical surface 5 of the microlens. The lithography process refers to a process of transferring a pattern on a photosensitive material (such as a photoresist) using optical technology. The overlay process refers to a process of aligning patterns between different layers in multiple lithography steps, including but not limited to thick film overlay, local overlay, thin film overlay, etc. The lithography process and the overlay process enable the multiple microlens glue columns to correspondingly map the expected patterns corresponding to the corresponding local silicon column arrays 3 when covering the corresponding local silicon column arrays 3.

[0040] Step S106: Heat the micro-lens glue column array to soften multiple micro-lens glue columns and form a micro-lens spherical surface array.

[0041] In step S106, the micro-lens spherical surface array includes multiple micro-lens spherical surfaces 5. Each micro-lens spherical surface 5 corresponds to a local silicon column array 3 and is supported by multiple local silicon columns 31 of the corresponding local silicon column array 3. When the micro-lens glue column array is heated, the second photoresist 4 will soften and form surface tension on the surface of the micro-lens glue columns. The micro-lens glue columns can deform by means of surface tension to change the contact situation with the local silicon columns 31, thereby forming micro-lens spherical surfaces 5 with different expected contact angles.

[0042] Please refer to Figure 4 , which is a flowchart of the sub-steps of step S106 provided by the embodiment of the present application. Heating the micro-lens glue column array to soften multiple micro-lens glue columns and form a micro-lens spherical surface array includes steps S1061 - S1062.

[0043] Step S1061: Heat the micro-lens glue column array at a preset temperature.

[0044] In step S1061, the preset temperature is the temperature at which the second photoresist 4 can undergo vitrification. In this embodiment, when the second photoresist 4 is AZ4620 photoresist, the preset temperature is set to 100 - 280 °C, and the conversion of the second photoresist 4 between vitrification and the normal state is controlled by adjusting the preset temperature.

[0045] Step S1062: When the preset temperature is greater than the glass transition temperature of the second photoresist, multiple micro-lens glue columns are heated to soften and respectively cover the side close to the front of multiple local silicon columns of the corresponding local silicon column array, so as to obtain multiple micro-lens spherical surfaces and form a micro-lens spherical surface array.

[0046] Please refer to Figure 3 , which is the second flowchart of the method for preparing a micro-lens spherical surface array provided by the embodiment of the present application. After etching the front side to obtain multiple local silicon column arrays, the method for preparing a micro-lens spherical surface array further includes step S201.

[0047] Step S201: Remove the first photoresist corresponding to multiple preset arrays.

[0048] In step S201, the first photoresist 2 corresponding to multiple preset arrays is the first photoresist 2 in the non-exposed area. After etching the front side to form the expected patterns of the corresponding preset arrays, it is necessary to remove the first photoresist 2 to prevent mixing with the second photoresist 4 and affecting the subsequent formation of the micro-lens spherical surface array.

[0049] In the above embodiments, the method steps for preparing the spherical micro-lens array are described. Below, with reference to the accompanying drawings, it will be further described how to increase the contact angle of the spherical micro-lens 5 in the method steps for preparing the spherical micro-lens array.

[0050] Please refer to Figures 6 - 9 , Figures 6 - 9 which shows cross-sectional views under different method steps for preparing the spherical micro-lens array.

[0051] As Figure 6 shown, first, a first photoresist 2 is spin-coated uniformly on the front surface of the silicon wafer 1 with a thickness of 0.2 - 5 microns. After drying the first photoresist 2, exposure and development processes are performed on the first photoresist 2. In the exposure process, the exposure area and the non-exposure area are determined according to various preset arrays. In the development process of the present application, the first photoresist 2 in the exposure area is dissolved and removed, so that according to the first photoresist 2 in the non-exposure area, the expected pattern corresponding to the shape of the spherical micro-lens 5 is projected onto the first photoresist 2 to form a plurality of local photoresist pillar arrays 21. Among them, the spacing between the plurality of local photoresist pillar arrays 21 and the spacing between the local photoresist pillars 211 in each local photoresist pillar array 21 can be adjusted according to the exposure area and the non-exposure area. Exemplarily, along the setting direction of the silicon wafer 1, the length of each local photoresist pillar array 21 among the plurality of local photoresist pillar arrays 21 can be 0.2 - 20 microns, and the spacing between each local photoresist pillar array 21 and the adjacent local photoresist pillar array 21 can be 1 - 30 microns. In this embodiment, the spacing between each local photoresist pillar array 21 and the adjacent local photoresist pillar array 21 is configured to be 30 microns, and the spacing between the local photoresist pillars 211 in each local photoresist pillar array 21 is 2 microns.

[0052] As Figure 7 shown, using the ICP etching process, a plurality of local silicon pillar arrays 3 are etched on the front surface according to various preset arrays. The height of the local silicon pillar arrays 3 can be 0.8 - 20 microns. The spacing between each local silicon pillar array 3 and the adjacent local silicon pillar array 3 can be 1 - 30 microns. After obtaining the plurality of local silicon pillar arrays 3, the first photoresist 2 corresponding to the plurality of local silicon pillar arrays 3 is removed. The height of the local silicon pillar arrays 3 can be adjusted accordingly according to the process flow of the ICP etching process.

[0053] As Figure 8As shown, a second photoresist 4 is coated on the front side of the silicon wafer, and the thickness can be 10 - 600 microns. In this embodiment, the thickness of the second photoresist 4 is 500 microns, and the second photoresist 4 is correspondingly coated on the corresponding positions of the multiple local silicon pillar arrays 3 on the front side, so as to align the second photoresist 4 with the corresponding local silicon pillar arrays 3 by using the overlay process, and then the second photoresist 4 covers the corresponding local silicon pillar arrays 3 to form microlens glue columns covering the corresponding local silicon pillar arrays 3, which helps to form a microlens spherical surface 5 with a larger radius of curvature on the front side of the silicon wafer, improving the focusing ability and optical coupling efficiency of the microlens, thereby enhancing its optical performance. At the same time, since the second photoresist 4 can be supported by the multiple local silicon pillar arrays 3, and the height of the local silicon pillar arrays 3 can be adjusted accordingly according to the process flow of the ICP etching process, therefore, when the heights of the local silicon pillar arrays 3 are different, the contact angles of the microlens spherical surfaces 5 formed by the second photoresist 4 are also different. Furthermore, the microlens spherical surfaces 5 with different contact angles can be controlled according to the corresponding relationship between the height of the local silicon pillar arrays 3 and the contact angle, and then the contact angle of the microlens spherical surfaces 5 can be increased according to the above corresponding relationship.

[0054] As Figure 9 shown, the microlens glue column array is heated at a preset temperature. The corresponding glass transition temperature is determined according to the material of the second photoresist 4, and then the preset temperature is determined. In this embodiment, the second photoresist 4 is AZ4620 photoresist, and the preset temperature is set to 100 - 280 °C. For a microlens glue column, when the second photoresist 4 undergoes glass transition, since the height of the microlens glue column is greater than the height of the local silicon pillar 31, therefore, the second photoresist 4 drives by means of surface tension so that the microlens glue column is sufficient to cover the corresponding local silicon pillar array 3 and is supported by the multiple local silicon pillars 31 to form the microlens spherical surface 5.

[0055] As Figure 10 shown, for a microlens spherical surface 5. The microlens spherical surface 5 is supported by the corresponding multiple local silicon pillars 31, and the expected patterns corresponding to the multiple local silicon pillars 31 are aligned to the microlens spherical surface 5 through the photolithography process and the overlay process. The size of the contact angle formed by the microlens spherical surface 5 will be affected by the size and shape of the local silicon pillars 31. In this application, a variety of different contact angles can be adjusted by controlling the etching process of the local silicon pillars 31, and the contact angle of the microlens spherical surface 5 can be increased by the contact between the multiple local silicon pillars 31 and the microlens glue column.

[0056] Please refer to Figure 5 , which is a schematic structural diagram of a system for preparing a microlens spherical surface array provided by an embodiment of the present application. The present application also provides a system 11 for preparing a microlens spherical surface array. The system 11 for preparing a microlens spherical surface array includes a photoresist coating device 110, an exposure and development device 111, a first photoresist processing device 112, a second photoresist processing device 113, and a heating device 114.

[0057] The photoresist coating device 110 is used to spin-coat a first photoresist 2 on the front side of the silicon wafer 1.

[0058] The exposure and development device 111 is used to perform exposure and development on the first photoresist 2 to obtain a plurality of local photoresist column arrays 21. Each local photoresist column array 21 includes a plurality of local photoresist columns 211.

[0059] The first photoresist processing device 112 is used to etch the front side according to the plurality of local photoresist column arrays 21 to obtain a plurality of local silicon column arrays 3. Each local silicon column array 3 includes a plurality of local silicon columns 31. Each local silicon column array 3 corresponds to a local photoresist column array 21, and the plurality of local silicon columns 31 correspond one-to-one to the plurality of local photoresist columns 211 of the corresponding local photoresist column array 21.

[0060] The photoresist coating device 110 is also used to coat a second photoresist 4 on the front side.

[0061] The second photoresist processing device 113 is used to cover the second photoresist 4 on one side of the plurality of local silicon column arrays 3 close to the front side by using a lithography process and an overlay process to obtain a microlens photoresist column array. The microlens photoresist column array includes a plurality of microlens photoresist columns. Each microlens photoresist column covers the plurality of local silicon columns 31 of the corresponding local silicon column array 3.

[0062] The heating device 114 is used to heat the microlens photoresist column array so that the plurality of microlens photoresist columns are softened and formed into a microlens spherical surface array. The microlens spherical surface array includes a plurality of microlens spherical surfaces 5. Each microlens spherical surface 5 corresponds to a local silicon column array 3 and is supported by the plurality of local silicon columns 31 of the corresponding local silicon column array 3.

[0063] In the above embodiment, by exposing and developing the first photoresist spin-coated on the front side of the silicon wafer, the first photoresist corresponding to a variety of preset arrays is obtained in advance, and the corresponding local silicon column arrays are etched on the front side according to the variety of preset arrays by an ICP etching process, so that when the second photoresist is coated, the second photoresist can be supported by the local silicon column arrays to obtain a microlens photoresist column array, and then a microlens spherical surface array is formed when the microlens photoresist column array is heated; at the same time, the formed local silicon column arrays can also be controlled by controlling the lithography process and the overlay process, and then the size of the contact angle can be controlled.

[0064] Obviously, those skilled in the art can make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalent technologies, this application is also intended to include these changes and modifications.

[0065] It should be understood that although the steps in the flowcharts of the accompanying drawings are shown sequentially in the direction of the arrows, these steps are not necessarily executed sequentially in the order indicated by the arrows. Unless otherwise clearly stated in this document, there is no strict order restriction for the execution of these steps, and they can be executed in other orders. Moreover, at least a part of the steps in the flowcharts of the accompanying drawings may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be executed alternately or in turn with at least a part of other steps or sub-steps or stages of other steps.

[0066] The above are only the preferred embodiments of the present application, and of course, the scope of rights of the present application cannot be limited thereby. Therefore, equivalent changes made according to the claims of the present application still fall within the scope covered by the present application.

Claims

1. A method for preparing a spherical microlens array, characterized in that: The method for preparing a spherical microlens array comprises: Spin coating a first photoresist on the front side of the silicon wafer; Expose and develop the first photoresist to obtain a plurality of local glue column arrays, each of which includes a plurality of local glue columns; According to the plurality of local glue column arrays, etching the front surface to obtain a plurality of local silicon column arrays, each local silicon column array includes a plurality of local silicon columns, each local silicon column array corresponds to a local glue column array, and the plurality of local silicon columns correspond one to one to the plurality of local glue columns of the corresponding local glue column array; Applying a second photoresist on the front surface; Using photolithography and overlay processes to cover the second photoresist on one side of the plurality of local silicon pillar arrays close to the front surface to obtain a microlens glue pillar array, wherein the microlens glue pillar array includes a plurality of microlens glue pillars, each of which covers a plurality of local silicon pillars of a corresponding local silicon pillar array; The microlens glue column array is heated to soften the plurality of microlens glue columns to form a microlens spherical surface array, wherein the microlens spherical surface array includes a plurality of microlens spherical surfaces, each microlens spherical surface corresponds to a local silicon column array and is supported by a plurality of local silicon columns of the corresponding local silicon column array; The first photoresist and the second photoresist are different positive photoresists; the height of the microlens glue column is greater than the height of the local silicon column.

2. The method for preparing a spherical microlens array according to claim 1, characterized in that: The first photoresist is exposed and developed to obtain a plurality of local photoresist column arrays, including: According to a plurality of preset arrays, respectively determining the exposure area and the non-exposure area of ​​the first photoresist, wherein different preset arrays have different exposure areas, and each preset array corresponds to a local glue column array; Performing light treatment on the first photoresist according to the exposure area and the non-exposure area; The first photoresist after the light treatment is developed to project the plurality of preset arrays onto the first photoresist accordingly, so that the plurality of local glue pillars of each local glue pillar array are arranged on the front surface according to the corresponding preset array to obtain the plurality of local glue pillar arrays.

3. The method for preparing a spherical microlens array according to claim 2, characterized in that: The plurality of local silicon pillar arrays are obtained by etching on the front surface according to the plurality of preset arrays using an ICP etching process.

4. The method for preparing a spherical microlens array according to claim 2, characterized in that: After etching the front surface to obtain a plurality of local silicon pillar arrays, the method further comprises: The first photoresists corresponding to the plurality of preset arrays are removed.

5. The method for preparing a spherical microlens array according to claim 1, characterized in that: The microlens glue column array is heated to soften the plurality of microlens glue columns to form a microlens spherical array, comprising: Heating the microlens glue column array at a preset temperature; When the preset temperature is greater than the glass transition temperature of the second photoresist, the plurality of microlens glue columns are heated to soften and respectively cover a plurality of local silicon columns of the corresponding local silicon column array close to the front surface to obtain the plurality of microlens spherical surfaces to form the microlens spherical surface array.

6. A system for preparing a microlens spherical array, characterized in that: The system for preparing a microlens spherical array comprises: A photoresist coating device, used for spin coating a first photoresist on the front side of the silicon wafer; An exposure and development device, used for exposing and developing the first photoresist to obtain a plurality of local glue column arrays, each of which includes a plurality of local glue columns; A first photoresist processing device is used to etch the front surface according to the plurality of local glue column arrays to obtain a plurality of local silicon column arrays, each local silicon column array includes a plurality of local silicon columns, each local silicon column array corresponds to a local glue column array, and the plurality of local silicon columns correspond to the plurality of local glue columns of the corresponding local glue column array one by one; the photoresist coating device is also used to coat a second photoresist on the front surface; A second photoresist processing device, used for covering the second photoresist on a side of the plurality of local silicon pillar arrays close to the front surface by using a photolithography process and an overlay process to obtain a microlens glue pillar array, wherein the microlens glue pillar array includes a plurality of microlens glue pillars, each of which covers a plurality of local silicon pillars of a corresponding local silicon pillar array; A heating device is used to heat the microlens glue column array to soften and shape the multiple microlens glue columns to obtain a microlens spherical surface array, wherein the microlens spherical surface array includes multiple microlens spherical surfaces, each microlens spherical surface corresponds to a local silicon column array, and is supported by multiple local silicon columns of the corresponding local silicon column array; The first photoresist and the second photoresist are different positive photoresists; the height of the microlens glue column is greater than the height of the local silicon column.

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