A lens array and a method for preparing the same

Abstract

The present application relates to the field of microlens technology, and discloses a lens array and a preparation method thereof, with the purpose of providing a preparation method for a lens array with a relatively high arch height. The preparation method of the lens array comprises the following steps: depositing a first film layer on a first substrate, and preparing a cone-shaped structure array through a composition process; depositing a second film layer on the cone-shaped structure array, and covering the top of the cone-shaped structure to form a lens-shaped structure array, wherein the top of the lens-shaped structure is an arc surface. The lens array is prepared by the above-mentioned preparation method, wherein the lens array comprises a plurality of lenses arranged in an array, and the arch heights of the plurality of lenses are the same and the arch heights are greater than or equal to a set value.

Description

Technical Field

[0001] The present application relates to the field of microlens technology, and in particular to a lens array and a method for preparing the same. Background Art

[0002] Currently, the existing nanoimprint lens template is provided by photolithography thermal reflow, but the thermal reflow method has great limitations in preparing high-arch lens structures. However, some projects require lens structures with higher arch heights, which cannot be prepared using only the current photolithography thermal reflow process. Summary of the invention

[0003] The present application discloses a lens array and a method for preparing the same, with the aim of providing a method for preparing a lens array with a relatively high arch height.

[0004] In order to achieve the above objectives, this application provides the following technical solutions:

[0005] A method for preparing a lens array, comprising the following steps:

[0006] Depositing a first film layer on a first substrate, and forming a cone structure array through a patterning process;

[0007] A second film layer is deposited on the cone-shaped structure array to cover the top of the cone-shaped structure to form a lens-shaped structure array, wherein the top of the lens-shaped structure is a curved surface.

[0008] Optionally, depositing a first film layer on the first substrate and forming a cone structure array through a patterning process includes:

[0009] Coating a third film layer on the first film layer to form a grating structure pattern;

[0010] The first film layer is etched to form the cone structure array using the grating structure pattern as a mask.

[0011] Optionally, etching the first film layer to form the cone-shaped structure array includes:

[0012] The first film layer is etched by dry etching process to form the cone structure array.

[0013] Optionally, the step of preparing a grating structure pattern comprises:

[0014] Preparing and forming a rectangular grating structure pattern;

[0015] The step of etching the first film layer to form the cone-shaped structure array comprises:

[0016] The first film layer is etched to form a pyramid structure array.

[0017] Optionally, etching the first film layer to form a pyramid structure array includes:

[0018] The first film layer is etched to form a triangular pyramid structure array.

[0019] Optionally, the step of preparing a grating structure pattern comprises:

[0020] Preparing and forming a circular grating structure pattern;

[0021] The step of etching the first film layer to form the cone-shaped structure array comprises:

[0022] The first film layer is etched to form a cone-shaped structure array.

[0023] Optionally, coating a third film layer on the first film layer and preparing a grating structure pattern includes:

[0024] A first nano-imprint adhesive layer is coated on the first film layer, and a grating structure pattern is formed by adopting a nano-imprint process.

[0025] Optionally, coating a third film layer on the first film layer and preparing a grating structure pattern includes:

[0026] A photoresist layer is coated on the first film layer, and a photolithography process is adopted to form a grating structure pattern.

[0027] Optionally, the method for preparing the lens array further comprises the following steps:

[0028] The lens array is obtained by using the lens-shaped structure array as a template and performing two nano-imprinting adhesive transfers.

[0029] Optionally, the lens array is obtained by using the lens-shaped structure array as a template and performing two nanoimprinting plastic transfers, specifically comprising:

[0030] Providing a second substrate, and depositing a second nanoimprint adhesive layer on the second substrate;

[0031] Using the lens-shaped structure array as an imprint template, forming a lens-shaped groove array in the second nanoimprint adhesive layer by using a nanoimprint process;

[0032] Providing a third substrate, and depositing a third nanoimprint adhesive layer on the third substrate;

[0033] The lens-shaped groove array is used as an imprint template, and the third nanoimprint adhesive layer is formed into a cylindrical lens array by using a nanoimprint process.

[0034] Optionally, the transmittance of the third nanoimprint adhesive layer is greater than the transmittance of at least one of the first film layer and the second film layer; and / or the refractive index of the third nanoimprint adhesive layer is greater than the refractive index of at least one of the first film layer and the second film layer.

[0035] Optionally, depositing a first film layer on the first substrate includes:

[0036] A SiO2 film layer is deposited on the first substrate.

[0037] Optionally, depositing a second film layer on the cone-shaped structure array includes:

[0038] A metal film layer is deposited on the pyramidal structure array.

[0039] Optionally, depositing a second film layer on the cone-shaped structure array includes:

[0040] The second film layer is formed by deposition using any one of chemical vapor deposition, magnetron sputtering deposition, or evaporation processes.

[0041] A lens array is prepared by any of the preparation methods described above, wherein the lens array comprises a plurality of lenses arranged in an array, the plurality of lenses have the same arch height and the arch height is greater than or equal to a set value.

[0042] Optionally, the set value is 30 μm.

[0043] Optionally, there is a gap between adjacent lenses.

[0044] Optionally, bottoms of adjacent lenses are connected to each other. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 A schematic diagram of the process of preparing a microlens array using a photolithography thermal reflow method;

[0046] Figure 2 A schematic diagram of the morphology change of the photoresist pattern during thermal reflow;

[0047] Figure 3 A flow chart of a method for preparing a lens array provided in an embodiment of the present application;

[0048] Figure 4 A schematic diagram of a process of manufacturing a lens array provided in an embodiment of the present application;

[0049] Figure 5 A schematic diagram of the structure of a lens array provided in one embodiment of the present application. DETAILED DESCRIPTION

[0050] Currently available nanoimprint lens templates are provided by photolithography thermal reflow. Figure 1 This is a process flow chart of preparing microlenses by photolithography thermal reflow, which mainly includes the following steps:

[0051] (a), the photoresist 20 on the substrate 10 is exposed under the shielding of the mask 30, and the exposure pattern is circular, rectangular or long strip, etc., Figure 1 Take a rectangle as an example;

[0052] (b), developing the exposed photoresist 20 and cleaning the residual substances to obtain a pattern of the photoresist 20;

[0053] (c) placing the substrate 10 on a heating platform so that the pattern of the photoresist 20 is thermally melted into the shape of a microlens.

[0054] Figure 2 The figure is a schematic diagram of the morphological changes of the photoresist pattern during the thermal reflow process, including: (d) the residual solvent (Solvent) in the photoresist evaporates, and the pattern volume decreases slightly; (e) the beginning of thermal reflow: the molecular motion energy increases, the fluidity increases, and the microlens contour begins to form, the volume remains unchanged, the slope angle decreases, and the arch height increases; (f) stress release: during the cooling process, the stress is released to the equilibrium state, forming a microlens morphology, the volume remains unchanged, and the slope angle tends to be stable. Figure 2 As shown, the arch height of the lens prepared by the thermal reflow process is limited by the thickness of the glue coating and the process, and is generally between 5μm and 30μm, which is difficult to meet the requirements for the arch height of the lens structure in some current projects.

[0055] Based on the above research, the present application discloses a lens array and a method for preparing the same, with the aim of providing a method for preparing a lens array, which can prepare lenses with higher arch heights, thereby meeting the current demand for high arch height lens products in various fields.

[0056] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0057] like Figure 3 As shown, an embodiment of the present application provides a method for preparing a lens array, which includes the following steps:

[0058] Step 101, reference Figure 4 As shown in (a), (b) and (c), a first film layer 21 is deposited on a first substrate 11, and an array of cone-shaped structures 210 is formed by a patterning process;

[0059] Step 102, reference Figure 4 As shown in (d) in the figure, a second film layer 22 is deposited on the array of cone-shaped structures 210 to cover the top of the cone-shaped structures 210 to form an array of lens-shaped structures 3, and the top of the lens-shaped structures 3 is a curved surface.

[0060] The preparation method of the lens array provided in the embodiment of the present application first adopts a patterning process to prepare an array of cone-shaped structures, and then covers the sharp corners of the cone-shaped structure array by depositing a film layer to form a smooth lens-shaped structure array. The preparation method is not limited by the thermal reflow process, the arch height range can be greatly improved, and a lens array with a higher arch height can be prepared, which greatly broadens the range of process adjustment capabilities, provides the possibility of preparing high-arch height and high-performance lens devices, and has the advantages of simple and feasible operation.

[0061] Specifically, the lens array obtained by the lens array preparation method of the embodiment of the present application can have a lens arch height of more than 30 μm. Different arch height effects can be achieved by adjusting the thickness of the film deposition and the parameters of the composition process, which can well meet the needs of various fields for lens products with different arch heights.

[0062] In a specific embodiment, step 101, depositing a first film layer on a first substrate and forming a cone structure array by a patterning process, may include the following steps:

[0063] Step 201, reference Figure 4 As shown in (a) and (b), a third film layer 23 is coated on the first film layer 21, and a pattern forming a grating structure 230 is prepared;

[0064] Step 202, reference Figure 4 As shown in (b) and (c) of FIG. 1 , the pattern of the grating structure 230 is used as a mask to etch the first film layer 21 to form an array of cone-shaped structures 210 .

[0065] In a specific embodiment, step 202, etching the first film layer to form a cone-shaped structure array, may specifically include:

[0066] The first film layer is etched to form a cone structure array by using a dry etching process.

[0067] In a specific embodiment, step 201, preparing and forming a grating structure pattern, specifically includes: preparing and forming a rectangular grating structure pattern. In other words, the prepared grating structure is a plurality of rectangular blocks arranged in an array.

[0068] Furthermore, step 202, etching the first film layer to form a cone-shaped structure array, specifically includes: etching the first film layer to form a pyramid-shaped structure array. In other words, the cone-shaped structures formed by etching are pyramid-shaped structures.

[0069] Exemplarily, in step 202, the first film layer may be etched to form a triangular pyramid structure array.

[0070] In another specific embodiment, step 201, preparing a grating structure pattern, specifically includes: preparing a circular grating structure pattern. In other words, the prepared grating structure is a plurality of circular structures arranged in an array.

[0071] Furthermore, step 202, etching the first film layer to form a cone-shaped structure array, specifically includes: etching the first film layer to form a cone-shaped structure array. In other words, the cone-shaped structures formed by etching are cone-shaped structures.

[0072] Of course, in the preparation method of the embodiment of the present application, the grating structure is not limited to a rectangular grating or a circular grating, and the conical structure is not limited to a prism or a cone. The grating structure and the conical structure may also have other shapes, and the specific final shape may be obtained according to the process parameters during actual operation.

[0073] In a specific embodiment, in step 201, a nanoimprinting process may be used to form a grating structure.

[0074] Exemplarily, step 201, coating a third film layer on the first film layer and preparing a grating structure pattern, may specifically include the following steps:

[0075] A first nano-imprint adhesive layer is coated on the first film layer, and a grating structure pattern is formed by adopting a nano-imprint process.

[0076] In another specific embodiment, in step 201, a photolithography process may be used to form a grating structure.

[0077] Exemplarily, step 201, coating a third film layer on the first film layer and preparing a grating structure pattern, may specifically include the following steps:

[0078] A photoresist layer is coated on the first film layer, and a photolithography process is adopted to form a grating structure pattern.

[0079] Based on the above embodiments, in a specific embodiment, the method for preparing the lens array provided in the embodiment of the present application may further include the following steps:

[0080] Step 103, reference Figure 4As shown in (d), (e) and (f), the lens array 5 is obtained by using the lens-shaped structure 3 array as a template and transferring the nanoimprint glue twice.

[0081] Exemplarily, step 103, using the lens-shaped structure array as a template, and obtaining the lens array by two nanoimprinting adhesive transfers, may specifically include the following steps:

[0082] Step 301, reference Figure 4 As shown in (d) and (e), a second substrate 12 is provided, and a second nanoimprint adhesive layer 24 is deposited on the second substrate 12; an array of lens-shaped structures 3 is used as an imprint template, and a lens-shaped groove 4 array is formed in the second nanoimprint adhesive layer 24 by a nanoimprint process;

[0083] Step 302, reference Figure 4 As shown in (e) and (f), a third substrate 13 is provided, and a third nanoimprint adhesive layer is deposited on the third substrate 13; the lens-shaped groove 4 array is used as an imprint template, and the third nanoimprint adhesive layer is formed into a lens 5 array by a nanoimprint process.

[0084] Specifically, the lens-shaped structure array formed in step 102 includes a two-layer structure of a first film layer and a second film layer. The patterns of the first film layer and the second film layer are limited by their preparation process, and the refractive index and transmittance may not meet the requirements of the optical lens array. Therefore, a lens array that meets the requirements of the optical lens can be obtained by two nanoimprinting adhesive transfers.

[0085] Exemplarily, the third nanoimprint adhesive layer ultimately used to form the lens array has a transmittance greater than the transmittance of at least one of the first film layer and the second film layer; and / or a refractive index greater than the refractive index of at least one of the first film layer and the second film layer.

[0086] In a specific embodiment, the first film layer may be a SiO2 film layer; that is, step 101, depositing the first film layer on the first substrate, specifically includes: depositing the SiO2 film layer on the first substrate.

[0087] For example, the thickness of the deposited SiO2 film layer may be 20 μm to 100 μm, which may be adjusted according to the requirement of the lens arch height.

[0088] For example, a chemical vapor deposition process may be used to form the SiO2 film layer, and the specific process conditions may be: 150°C temperature and 400W power.

[0089] In a specific embodiment, the second film layer may be a metal film layer; that is, step 102, depositing the second film layer on the cone-shaped structure array, specifically includes: depositing the metal film layer on the cone-shaped structure array.

[0090] Of course, the first film layer is not limited to a SiO2 film layer, and the second film layer is not limited to a metal layer. The first film layer and the second film layer may also be made of other materials as long as they can meet the requirements of deposition and patterning.

[0091] In a specific embodiment, step 102, depositing a second film layer on the cone structure array, may specifically include:

[0092] The second film layer is formed by deposition using any one of chemical vapor deposition (CVD), magnetron sputtering deposition (Sputter), or evaporation processes.

[0093] In addition, the embodiment of the present application further provides a lens array, which is prepared by any of the preparation methods described above, wherein the reference Figure 4 (f) and Figure 5 As shown, the lens array includes a plurality of lenses 5 arranged in an array, and the plurality of lenses 5 have the same arch height h, and the arch height h is greater than or equal to a set value.

[0094] Exemplarily, the above setting value is 30 μm. For example, the arch height of each lens in the lens array can be 30 μm, 35 μm, or 40 μm.

[0095] In a specific embodiment, reference Figure 4 As shown in (f) in FIG. 1 , in the lens array provided in the embodiment of the present application, there is a gap between adjacent lenses 5 .

[0096] In another specific embodiment, reference Figure 5 As shown, in the lens array provided in the embodiment of the present application, the bottoms of adjacent lenses 5 are connected to each other, that is, the lens array is a close-contact lens array.

[0097] Specifically, whether the lenses are in close contact or have gaps between them can be achieved by adjusting specific parameters in the preparation process; for example, it can be achieved by adjusting any one or several of the parameters such as the gap between the grating structures, the etching time of the first film layer, the deposition thickness of the second film layer, etc.

[0098] In addition, it should be noted that in the method for preparing the lens array of the present invention, the specific process is not limited to the above-mentioned embodiments of the present invention, and the shapes of the various structures provided in the present invention, the parameters of the specific process, etc. are only examples of some embodiments of the present application, and the specific scheme of the present invention is not limited to this.

[0099] Obviously, those skilled in the art can make various changes and modifications to the embodiments of the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A method for preparing a lens array, wherein: The following steps are involved: Depositing a first film layer on a first substrate, and forming a cone structure array through a patterning process; Depositing a second film layer on the cone-shaped structure array to cover the top of the cone-shaped structure to form a lens-shaped structure array, wherein the top of the lens-shaped structure is a curved surface; The lens array is obtained by using the lens-shaped structure array as a template and performing two nanoimprinting transfers, wherein the process specifically includes: Providing a second substrate, and depositing a second nanoimprint adhesive layer on the second substrate; Using the lens-shaped structure array as an imprint template, forming a lens-shaped groove array in the second nanoimprint adhesive layer by using a nanoimprint process; Providing a third substrate, and depositing a third nanoimprint adhesive layer on the third substrate; Using the lens-shaped groove array as an imprint template, the third nanoimprint adhesive layer is formed into a cylindrical lens array by a nanoimprint process; The transmittance of the third nanoimprint adhesive layer is greater than the transmittance of at least one of the first film layer and the second film layer; and / or the refractive index of the third nanoimprint adhesive layer is greater than the refractive index of at least one of the first film layer and the second film layer.

2. The method for preparing a lens array according to claim 1, wherein: The method of depositing a first film layer on a first substrate and forming a cone structure array by a patterning process comprises: Coating a third film layer on the first film layer to form a grating structure pattern; The first film layer is etched to form the cone structure array using the grating structure pattern as a mask.

3. The method for preparing a lens array according to claim 2, wherein: The step of etching the first film layer to form the cone-shaped structure array comprises: The first film layer is etched by dry etching process to form the cone structure array.

4. The method for preparing a lens array according to claim 2, wherein: The method of preparing and forming a grating structure pattern comprises: Preparing and forming a rectangular grating structure pattern; The step of etching the first film layer to form the cone-shaped structure array comprises: The first film layer is etched to form a pyramid structure array.

5. The method for preparing a lens array according to claim 4, wherein: The first film layer is etched to form a pyramid structure array, comprising: The first film layer is etched to form a triangular pyramid structure array.

6. The method for preparing a lens array according to claim 2, wherein: The method of preparing and forming a grating structure pattern comprises: Preparing and forming a circular grating structure pattern; The step of etching the first film layer to form the cone-shaped structure array comprises: The first film layer is etched to form a cone-shaped structure array.

7. The method for preparing a lens array according to claim 2, wherein: The step of coating a third film layer on the first film layer and preparing a grating structure pattern comprises: A first nano-imprint adhesive layer is coated on the first film layer, and a grating structure pattern is formed by adopting a nano-imprint process.

8. The method for preparing a lens array according to claim 2, wherein: The step of coating a third film layer on the first film layer and preparing a grating structure pattern comprises: A photoresist layer is coated on the first film layer, and a photolithography process is adopted to form a grating structure pattern.

9. The method for preparing a lens array according to any one of claims 1 to 8, wherein: The step of depositing a first film layer on a first substrate comprises: A SiO2 film layer is deposited on the first substrate.

10. The method for preparing a lens array according to any one of claims 1 to 8, wherein: The step of depositing a second film layer on the cone-shaped structure array comprises: A metal film layer is deposited on the pyramidal structure array.

11. The method for preparing a lens array according to any one of claims 1 to 8, wherein: The step of depositing a second film layer on the cone-shaped structure array comprises: The second film layer is formed by deposition using any one of chemical vapor deposition, magnetron sputtering deposition, or evaporation processes.

12. A lens array, prepared by the preparation method according to any one of claims 1 to 11, wherein: The lens array includes a plurality of lenses arranged in an array, and the plurality of lenses have the same arch height and the arch height is greater than or equal to a set value.

13. The lens array according to claim 12, wherein: The set value is 30 μm.

14. The lens array according to claim 13, wherein: There is a gap between adjacent lenses.

15. The lens array according to claim 13, wherein: The bottoms of adjacent lenses are connected to each other.

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