CN111175861B - Design and preparation method of multi-focal-length curved fly-eye lens - Google Patents
Design and preparation method of multi-focal-length curved fly-eye lens Download PDFInfo
- Publication number
- CN111175861B CN111175861B CN202010052554.1A CN202010052554A CN111175861B CN 111175861 B CN111175861 B CN 111175861B CN 202010052554 A CN202010052554 A CN 202010052554A CN 111175861 B CN111175861 B CN 111175861B
- Authority
- CN
- China
- Prior art keywords
- eye lens
- substrate
- sub
- eye
- focal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B3/00—Simple or compound lenses
- G02B3/0006—Arrays
- G02B3/0012—Arrays characterised by the manufacturing method
- G02B3/0031—Replication or moulding, e.g. hot embossing, UV-casting, injection moulding
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
- G02B27/0012—Optical design, e.g. procedures, algorithms, optimisation routines
Abstract
The invention relates to the technical field of machining, and discloses a design and preparation method of a multi-focal-length curved fly-eye lens. Firstly, carrying out optical design on a curved fly-eye lens to obtain the chord length of each level of sub-eye lens; selecting a substrate and spin-coating a photoresist on the surface of the substrate to form a photoresist mask with a micro-lens array; etching the substrate coated with the photoresist mask, and transferring the microlens array to the substrate; cleaning and removing the photoresist on the surface of the substrate, and passivating the substrate; laying a polymer on the microlens array of the passivated substrate, replicating the microlens array onto a polymer layer, and peeling the polymer layer from the substrate; carrying out reverse demoulding by using PDMS pre-polymerization liquid, and transferring the polymer micro-lens array to a PDMS film; and copying the micro-lens array on the PDMS film to prepare the designed curved fly-eye lens. The invention has the advantages of low cost, controllable curvature, simple processing process and high repeatability.
Description
Technical Field
The invention relates to the technical field of micro-machining, in particular to a design and preparation method of a multi-focal-length curved fly-eye lens.
Background
With the rapid development of electronic monitoring, mobile phone photography, image recognition and artificial intelligence, practical application puts higher demands on an imaging system, and an optical imaging system and an optical system develop towards miniaturization, compactness and integration. The traditional optical imaging system generally adopts a lens group for imaging, has more lenses, large volume and complex structure, and is difficult to realize integration and fusion with various miniaturized systems. The curved compound eye imaging system has the advantages of large field angle, large depth of field, compact structure and high sensitivity in the aspect of capturing object information moving at high speed.
The curved fly-eye lens has a structure that the upper surface is a plane and the lower surface is a curved surface, sub-eye micro lenses with micron-sized sagitta and sagitta are densely arranged on the curved surface of the lower surface, wherein the sagitta of the micro lenses is h, and the curved fly-eye lens has basic imaging functions of focusing, imaging and the like of a traditional lens. The TOMBO system proposed by the japanese research group is a combination of a planar microlens array and a planar photosensor, but this method has a small field angle and a very limited application range. Later, researchers at home and abroad have proposed a combined application mode of a curved fly-eye lens and a planar photosensitive sensor. However, due to the existence of the field curvature, when an object is imaged by the curved fly-eye lens, the object is not a plane to which vision is accustomed but a corresponding curved focal plane. The defocusing phenomenon can occur between the curved focal plane and the plane pixel surface of the photosensitive sensor, the more far away from the central area, the more remarkable the defocusing phenomenon is, and the imaging quality of the curved fly-eye lens is influenced to a great extent. In the conventional optical system, a lens group is generally used to correct aberrations, but as mentioned above, the conventional optical system has the problems of large volume, complex structure, difficult processing and assembly, high cost, tolerance accumulation and the like.
With the development of micro-nano processing technology, researchers at home and abroad propose various experimental schemes to prepare the curved fly-eye lens. The following methods are available: 1. laser direct writing, and directly processing a micro-lens array on the curved surface; 2. performing femtosecond laser hot pressing, namely processing a micro-lens array on a silicon chip by using femtosecond laser, demolding by using PMMA, and then hot pressing the PMMA onto a sphere; 3. performing femtosecond laser chemical corrosion, enabling the femtosecond laser to stay on the curved surface for 0.5s to form a small pit, and performing isotropic chemical corrosion by using 10% HF acid to obtain a curved surface micro-lens array; and 4, making a PDMS mold, etching a required planar microlens array on the planar PDMS film, covering the planar microlens array on a container filled with PDMS pre-polymerization liquid, placing a small ball on the PDMS film, enabling the film to generate spherical deformation by using the gravity of the small ball, and preparing the curved microlens array after the PDMS pre-polymerization liquid is cured. However, the above-mentioned mainstream process has the following problems: the processing cycle is long, the cost is high, the curvature of the curved fly-eye lens is uncontrollable, the repeatability is low, and the consistency of the sub-eye morphology is poor.
Patent CN105467477A proposes a curved bionic fly-eye imaging device of a gradually-varying focal length lens array, which changes the focal length of the lens by calculating different distances from each stage of sub-eye lens to the photoelectric image sensor; and presetting that the lens crowns of the monocular lens subsystems are the same, and manufacturing each level of sub-eyes by using a photoetching column hot melting method. However, at present, a planar photolithography process is mostly adopted, and the finally prepared structure is a curved surface structure. How to complete the conversion from the planar structure to the curved structure and control the position of the sub-eye on the curved surface to match with the design value does not provide a specific feasible scheme, so that the method has some defects in practical operation.
Patent CN103616738A proposes a method for manufacturing a curved fly-eye microlens with different focal lengths, which uses a micro-processing technology to make an array of multiple units on a substrate, and covers an electrostatic thin film thereon, and the deformation of the electrostatic thin film can be changed by changing the magnitude of the applied voltage on different unit groups. Because each unit needs to be controlled independently, the method is not suitable for preparing small-unit and large-area array structures, the compound eye limitation is large, the requirement on the structure is high, and the design and manufacturing cost is increased.
Disclosure of Invention
The invention aims to provide a method for designing and preparing a multi-focal-length curved fly-eye lens, aiming at the technical problems in the prior art, and the method is simple and reliable, low in cost and high in repeatability.
In order to solve the problems proposed above, the technical scheme adopted by the invention is as follows:
a method for designing and preparing a multi-focal-length curved fly-eye lens comprises the following steps:
step S110: optically designing the curved fly-eye lens to enable the focal point of each stage of sub-eye lens to fall on the same focal plane and be matched with the image plane of the photosensitive component to obtain the chord length of each stage of sub-eye lens;
step S120: selecting a substrate according to a curved fly-eye lens obtained by optical design, and spin-coating a photoresist on the surface of the substrate to form a photoresist mask with a micro-lens array;
step S130: etching the substrate coated with the photoresist mask, and transferring the microlens array to the substrate;
step S140: cleaning and removing the photoresist on the surface of the substrate, and passivating the substrate;
step S150: laying a polymer on the microlens array of the passivated substrate, replicating the microlens array onto a polymer layer, and peeling the polymer layer from the substrate;
step S160: carrying out reverse demoulding by using PDMS pre-polymerization liquid, and transferring the polymer micro-lens array to a PDMS film;
step S170: and copying the micro-lens array on the PDMS film to prepare the designed curved fly-eye lens.
Further, in step S110, a specific process of performing optical design is as follows:
the light rays are made to enter from the upper surface plane end to the lower surface curved surface end of the curved fly-eye lens, and after being converged by the sub-eye lens, the focal point falls on the image surface of the photosensitive component;
grading the sub-eye lens, wherein the most central part of the lower surface corresponds to a 0-grade sub-eye, the grade of the sub-eye is gradually increased to n grades layer by layer, and the focal length of the 0-grade sub-eye is l0Focal length of each sub-eye is lnN is 1,2,3 …;
calculating to obtain the focal length l of each sub-eyenAnd according to the focal length l of each sub-eyenAnd obtaining the chord length S of the spherical cap of the sub-eye lens.
Further, the focal length l of each sub-eye is obtained through calculationnAnd obtaining the chord length S of the spherical cap of the sub-eye lens, wherein the specific process is as follows:
the incident angle of light is set as alpha, the refraction angle refracted by the upper surface of the curved fly-eye lens is set as theta, and when the light passes through the upper surface, refraction occurs, so that the formula (1) is obtained:
n0sinα＝nsinθ (1)
focal length l of each sub-eyenIs equal to the image space focal point f', and r is the curvature of the sub-eye lensRadius, from the formula of the image-side focus, to obtain formula (2):
obtaining formula (3) according to the geometrical relationship of the light path diagram:
simultaneous equations (2) and (3) yield equation (4):
namely, the change of the curvature radius r of the micro lens along with theta is obtained as shown in formula (5):
obtaining the chord length S of the spherical cap of the sub-eye lens according to the curvature radius r, as shown in formula (6):
wherein n is0Is the refractive index of air; n is the refractive index of photosensitive glue used for preparing the curved fly-eye lens; r is the curvature radius of the spherical crown of the curved fly-eye lens; h is0Is the sagittal height of the spherical cap of the sub-eye lens.
Further, the step S120 specifically includes: and coating an adhesive on the substrate in a spin coating manner, then coating photoresist, uniformly distributing the photoresist on the substrate by utilizing high-speed centrifugation, and then carrying out prebaking to obtain the photoresist mask with the micro-lens array.
Further, the step S130 specifically includes: and carrying out ICP etching on the part, which is not attached with the photoresist mask, on the substrate to obtain the microlens array with the same pattern as the photoresist mask.
Further, in step S140, a specific process of performing the passivation process is as follows:
soaking the etched substrate in an acetone solution to preliminarily remove the photoresist on the substrate;
mixing concentrated sulfuric acid and hydrogen peroxide according to the weight ratio of 3: 1, preparing a solution by mixing, putting the substrate into the solution, boiling, and removing the residual photoresist and part of impurities;
cleaning the sulfuric acid on the substrate by using clear water;
by C4F8And passivating the silicon wafer substrate, and forming a passivation layer on the surface of the silicon wafer.
Further, the step S150 specifically includes: placing a silicon wafer substrate with a micro-lens array in a mould, laying a polymer layer on the silicon wafer substrate, carrying out hot pressing treatment on the polymer layer at a glass transition temperature, and cooling and then peeling the polymer layer from the substrate to obtain the polymer micro-lens array.
Further, the step S160 specifically includes: placing the polymer micro-lens array in a mould, pouring PDMS (polydimethylsiloxane) pre-polymerization liquid, and placing the mould in a vacuum drying oven to be heated for a set time; and curing the PDMS pre-polymerization liquid to obtain a PDMS film with the microlens array pattern opposite to the polymer microlens array pattern.
Further, the step S170 specifically includes:
copying a micro-lens array on a PDMS film through an ultraviolet curing process, placing the PDMS film on a closed cavity, and deforming the PDMS film under the action of atmospheric pressure;
and pouring photosensitive adhesive into a concave spherical crown formed by the deformed film, placing a quartz glass sheet above the photosensitive adhesive, and curing under an ultraviolet lamp to obtain the designed curved fly-eye lens.
Further, the polymer layer includes COC, COP, PMMA, and PC.
Compared with the prior art, the invention has the beneficial effects that:
according to the design and preparation method of the multi-focal-length curved fly-eye lens, the curved fly-eye lens is subjected to optical design, so that the focal point of each stage of sub-eye lens is positioned on the same focal plane and matched with the image plane of the photosensitive component, and the problem of defocusing caused by mismatching of the curved focal plane and the plane image plane of the photosensitive component in the imaging process of the curved fly-eye lens is solved; the curved fly-eye lens obtained by design is prepared, and the preparation method has the advantages of low cost, controllable curvature, simple processing process and high repeatability.
Drawings
FIG. 1 is a flow chart of a method for designing and manufacturing a multi-focal-length curved fly-eye lens according to the present invention;
FIG. 2 is a diagram of a model of a curved fly-eye lens design provided by the present invention;
FIG. 3 is a cross-sectional view of a photolithographic reticle provided by the present invention;
FIG. 4 is a diagram of a silicon wafer substrate with a photoresist mask covered after lithographic development according to the present invention;
FIG. 5 is a diagram of a silicon wafer substrate with an array of micro-holes after etching passivation according to the present invention;
FIG. 6 is a schematic diagram of a hot-pressed polymer layer replication transfer of a microlens array on a silicon wafer according to the present invention;
FIG. 7 is a schematic view of a polymer layer with a microlens array after hot pressing according to the present invention;
FIG. 8 is a schematic diagram of reverse demolding by using PDMS pre-polymerization liquid provided by the present invention;
FIG. 9 is a schematic view of a PDMS film with a recessed microlens array obtained by reverse demolding according to the present invention;
FIG. 10 is a schematic view of the UV curing of a photosensitive adhesive according to the present invention;
FIG. 11 is a schematic view of an example curved fly-eye lens provided by the present invention.
Wherein: the device comprises a substrate, a photoresist mask, a substrate, a 4-micro-lens array, a 5-polymer layer, a 6-hot pressing limiting ring, a 7-polymer micro-lens array, 8-PDMS pre-polymerized liquid, a 9-PDMS film, 10-quartz glass, 11-photosensitive glue and a 12-closed cavity, wherein the substrate is a silicon wafer, and the photoresist mask is a photoresist mask.
Detailed Description
To facilitate an understanding of the invention, the invention will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.
Referring to fig. 1, the present invention further provides a method for designing and manufacturing a multi-focal-length curved fly-eye lens, which includes the following steps:
step S110: the curved fly-eye lens is optically designed, so that the focus of each stage of sub-eye lens is positioned on the same focal plane and matched with the image plane of the photosensitive component, and the defocusing phenomenon in the imaging process is solved. The size and the arrangement of the sagittal diameter (chord length) of each stage of sub-eye lens are obtained.
In this step, the curved fly-eye lens is optically designed, which is specifically described with reference to the curved fly-eye lens design model of fig. 2, and the design process is specifically as follows:
step S11: the light rays are made to enter from the upper surface plane end to the lower surface curved surface end of the curved fly-eye lens, and after being converged by the sub-eye lens, the focal point is made to fall on the image surface of a photosensitive component (such as a photosensitive sensor CMOS or CCD). The light rays directly pass through the lens to be irradiated onto the plane of the photosensitive component, so that the consumption of the light rays in the lens can be reduced.
Step S12: grading the sub-eye lens, correspondingly arranging 0-grade sub-eyes at the center of the lower surface of the curved fly-eye lens, gradually increasing the sub-eye series to n grades along with peripheral expansion, and obtaining the focal length l of the 0-grade sub-eyes0And focal length l of each sub-eyenAnd n is 1,2,3 ….
In this step, the vertical distance from the 0-level sub-eye to the image surface of the photosensitive component is set to be l0I.e. focal length of 0-order sub-eye is l0It is a preset value. The distances from the sub-eyes of 1,2,3 … … n to the image plane along the optical axis direction, i.e. the focal lengths of the image of the sub-eyes of each stage are respectively l1，l2，l3……ln. As can be seen in the figure, the closer to the edge region, the more l is in the progressive progression from level 0 to level nnThe focal point of each sub-eye is located on the image surface of the photosensitive component by increasing step by step, and the central axis of each micro-lens passes through the central point o of curvature.
Step S13: calculating to obtain the focal length l of each sub-eyenThe process is as follows:
assuming that the incident angle of light is alpha, the refraction angle refracted by the upper surface of the curved fly-eye lens is theta, the refracted light passes through the optical center of the sub-eye lens, namely, coincides with the optical axis of the sub-eye lens, and the reverse extension line of the refracted light passes through the curvature center point o of the spherical cap of the curved fly-eye lens, namely, the light is refracted when passing through the upper surface, so as to obtain formula (1):
n0sinα＝nsinθ (1)
wherein n is0Is the refractive index of air; n is the refractive index of the photosensitive adhesive of the material for preparing the curved fly-eye lens.
Focal length l of each sub-eyenIs equal to the image-side focal point f', and r is the radius of curvature of the sub-eye lens, i.e. as shown in equation (2):
step S14: from the light path diagram geometry in fig. 2, equation (3) can be given:
wherein R is the curvature radius of the spherical crown of the curved fly-eye lens; h is0Is the rise of the spherical cap of the sub-eye lens;
step S15: simultaneous equations (2) and (3) can be obtained as shown in equation (4):
that is, the change of the curvature radius r of the microlens with θ can be obtained as shown in equation (5):
step S16: the chord length S of the spherical cap of the sub-eye lens can be calculated according to the curvature radius r, as shown in formula (6):
the curved fly-eye lens is obtained according to the optical design, and the following steps are adopted to prepare the curved fly-eye lens.
Step S120: selecting a substrate and spin-coating a photoresist on the surface of the substrate to form a photoresist mask with a micro-lens array.
The method specifically comprises the steps of spin-coating an adhesive on the substrate, then coating photoresist, uniformly distributing the photoresist on the substrate by utilizing high-speed centrifugation, and then carrying out pre-baking to obtain the photoresist mask with the micro-lens array.
In the embodiment of the invention, the photoetching mask 1 shown in the attached figure 3 is adopted for photoetching, and after development and baking, the photoresist mask 2 which is attached to a silicon wafer substrate 3 and has a micro-lens array 4 structure and shown in the attached figure 4 can be obtained. The diameter of each level of micro-holes of the micro-hole array on the photoresist mask of fig. 3 is equal to the S value of each circle of sub-holes obtained in step S110.
The optical design objective of step S110 in the present application is to make the focal points of the sub-eyes of each circle fall on the same focal plane, because the distances from the sub-eyes to the focal plane are different, i.e. the focal distances are different. Therefore, the chord lengths of the sub-eyes are different, the larger the chord length of the sub-eyes is, the larger the focal length of the sub-eyes is, the sub-eyes are spherical caps, the chord length is also called the caliber, and the corresponding chord length under each focal length is obtained by manually setting the focal length. In the preparation process, a planar microlens array is prepared, the planar microlens array corresponds to the curved fly-eye lens, and the diameter of each circle of microlenses of the planar microlens array is equal to the chord length S of each sub-eye calculated in the step S110.
Step S130: etching the substrate 3 coated with the photoresist mask 2, and transferring the pattern of the micro-lens array 4 to the substrate 3;
in this step, specifically, ICP etching is performed on a place, which is not attached with the photoresist mask 1, on the substrate 3 to obtain a microlens array 4 with the same pattern as the photoresist mask 1, that is, the pattern of the microlens array 4 is transferred onto the substrate 3, as shown in fig. 5. The planar microlens array is processed on the silicon wafer substrate by adopting photoetching and ICP ion etching, and the processing precision is high.
Step S140: and cleaning to remove the photoresist on the surface of the substrate, and passivating the substrate 3.
The specific process of passivation in this step is as follows:
step S41: and soaking the etched silicon wafer substrate 3 in an acetone solution to primarily remove the photoresist on the silicon wafer substrate.
Step S42: mixing concentrated sulfuric acid and hydrogen peroxide according to the weight ratio of 3: mixing the silicon wafer substrate 3 with the solution in the ratio of 1, boiling the silicon wafer substrate 3 in the solution, and removing the residual photoresist and part of impurities.
Step S43: and cleaning the silicon wafer substrate 3 by using clean water to remove sulfuric acid.
Step S44: and passivating the silicon wafer substrate by using C4F8, and forming a passivation layer on the surface of the silicon wafer.
Step S150: a polymer is laid on the microlens array 4 of the passivated silicon wafer substrate, the microlens array 4 is replicated onto the polymer layer 5, and the polymer layer 5 is peeled off the substrate 3.
Specifically, as shown in fig. 6, a silicon wafer substrate 3 with a microlens array 4 is placed in a mold, a polymer layer 5, such as COC, COP, PMMA, PC, and the like, is laid on the silicon wafer substrate, the polymer layer 5 is subjected to hot pressing at a glass transition temperature of 135 ℃ to 145 ℃, the pressure range of 25KPa to 50KPa, and the rise of the convex microlens array is 20 μm to 40 μm, and after cooling, the polymer layer 5 is peeled off from the substrate 3, so that the polymer microlens array 7 shown in fig. 7 can be obtained.
In the step, in the process of transferring the microlens array pattern on the silicon wafer substrate to the polymer layer by adopting a hot pressing process, pressure is uniformly applied to the surface of the copolymerization layer, the rise of the sub-eye lens is uniform, and meanwhile, the size of the rise of the sub-eye lens can be controlled by controlling the preset hot pressing thickness.
Step S160: and (3) performing reverse demolding by using the PDMS pre-polymerization liquid 8, and transferring the polymer micro-lens array 7 onto a PDMS film 9.
Specifically, in this step, as shown in fig. 8, the polymer microlens array 7 is placed in a mold, the PDMS prepolymer liquid 8 is poured, and the mold is placed in a vacuum drying oven and heated for a set time, in this embodiment, the mold is heated at a temperature of 60 ° for 12 hours, so that the best effect is obtained. After the PDMS pre-polymerization liquid 8 is cured, a PDMS film 9 with elastic deformation is obtained, and as shown in fig. 9, the pattern of the microlens array is opposite to the pattern of the polymer microlens array 7, i.e., the convex microlens array is changed into an opposite concave microlens array.
Step S170: and copying the micro-lens array on the PDMS film 9 to prepare the designed curved fly-eye lens.
The method specifically comprises the steps of copying a micro-lens array on a PDMS film through an ultraviolet curing process, placing the PDMS film 9 on an air-extracting closed cavity 12 as shown in figure 10, and under the action of atmospheric pressure, deforming the PDMS film 9, wherein the deformation quantity and the atmospheric pressure form a linear relation through simulation;
the photosensitive adhesive 11 is poured into the concave spherical crown formed by the deformed film, a quartz glass sheet 10 is placed above the photosensitive adhesive, and the photosensitive adhesive is placed under an ultraviolet lamp for curing, so that the curved fly-eye lens shown in the attached drawing 11 can be prepared.
In the step S170, according to the linear relationship between the PDMS film deformation and the atmospheric pressure, the negative pressure inside the mold is measured by using an external differential pressure gauge, so that the curvature radius of the film deformation can be accurately controlled; the designed curved fly-eye lens is prepared by adopting an ultraviolet curing process, and has the advantages of short time, high efficiency, good repeatability and uniform surface appearance.
The design and manufacturing method of the above-described multi-focal-length curved fly-eye lens will be described in detail by specific examples below:
(1) setting the distance from the 0-level sub-eye to the image surface of the photosensitive chip to be 0.3mm, namely the focal length l of the 0-level sub-eye0Using the initial value l in accordance with the above-described equations (1) to (6) when the value is 0.3mm0The chord length of the sub-eye of 0 order is calculated, and the chord length of the sub-eye of each order is sequentially obtained, and specific data is shown in table 1:
TABLE 1
As can be seen from Table 1, the larger the number of sub-eye steps is, the larger the field angle of the curved fly-eye lens is, which can reach 140-180 degrees.
(2) And spin-coating a positive photoresist on the surface of the silicon wafer substrate, exposing and developing by using a photoetching mask plate, and forming a patterned photoresist mask on the surface of the silicon wafer substrate, wherein the pattern on the photoresist mask is a photoresist microlens array pattern.
(3) And transferring the micro-lens array on the photoetching photoresist mask to a silicon wafer substrate through dry etching.
(4) And cleaning to remove the photoresist, and passivating the silicon wafer substrate.
(5) And paving the cyclic olefin copolymer COC on the micropore array of the passivated silicon wafer substrate, and carrying out hot-pressing treatment. Placing a limiting ring with the same thickness on the periphery of the cycloolefin copolymer and the silicon wafer micropore array, heating to the glass transition temperature of the cycloolefin copolymer of more than 138 ℃, and simultaneously applying pressure of 40kPa for 15 min. And cooling to room temperature, and stripping to obtain the silicon wafer substrate containing the COC micro lens array.
(6) And (3) carrying out reverse demoulding by using the PDMS pre-polymerization liquid to obtain the PDMS film containing the micro-lens array female die.
(7) Sealing the PDMS film on a closed cavity, exhausting air to enable the surface of the film to generate spherical deformation, pouring photosensitive adhesive NOA63, and performing ultraviolet curing to obtain the designed curved fly-eye lens.
The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.
Claims (8)
1. A design and preparation method of a multi-focal-length curved fly-eye lens is characterized by comprising the following steps: the method comprises the following specific steps:
step S110: optically designing the curved fly-eye lens to enable the focal point of each stage of sub-eye lens to fall on the same focal plane and be matched with the image plane of the photosensitive component to obtain the chord length of each stage of sub-eye lens;
step S120: selecting a substrate according to a curved fly-eye lens obtained by optical design, and spin-coating a photoresist on the surface of the substrate to form a photoresist mask with a micro-lens array;
step S130: etching the substrate coated with the photoresist mask, and transferring the microlens array to the substrate;
step S140: cleaning and removing the photoresist on the surface of the substrate, and passivating the substrate;
step S150: laying a polymer on the microlens array of the passivated substrate, replicating the microlens array onto the polymer layer, and peeling the polymer layer from the substrate;
step S160: carrying out reverse demoulding by using PDMS pre-polymerization liquid, and transferring the polymer micro-lens array to a PDMS film;
step S170: copying a micro-lens array on the PDMS film to prepare the designed curved fly-eye lens;
in step S110, the specific process of performing optical design is as follows:
the light rays are made to enter from the upper surface plane end to the lower surface curved surface end of the curved fly-eye lens, and after being converged by the sub-eye lens, the focal point falls on the image surface of the photosensitive component;
grading the sub-eye lens, wherein the most central part of the lower surface corresponds to a 0-grade sub-eye, the grade of the sub-eye is gradually increased to n grades layer by layer, and the focal length of the 0-grade sub-eye is l0Focal length of each sub-eye is lnN is 1,2,3 …;
calculating to obtain the focal length l of each sub-eyenAnd according to the focal length l of each sub-eyenObtaining the chord length S of the spherical crown of the sub-eye lens;
the focal length l of each sub-eye is obtained through calculationnAnd obtaining the chord length S of the spherical cap of the sub-eye lens, wherein the specific process is as follows:
the incident angle of light is set as alpha, the refraction angle refracted by the upper surface of the curved fly-eye lens is set as theta, and when the light passes through the upper surface, refraction occurs, so that the formula (1) is obtained:
n0sinα＝n sinθ (1)
focal length l of each sub-eyenIs equal to the image side focal point f', r is the curvature radius of the sub-eye lens, and the formula (2) is obtained according to the formula of the image side focal point:
obtaining formula (3) according to the geometrical relationship of the light path diagram:
simultaneous equations (2) and (3) yield equation (4):
namely, the change of the curvature radius r of the micro lens along with theta is obtained as shown in formula (5):
obtaining the chord length S of the spherical cap of the sub-eye lens according to the curvature radius r, as shown in formula (6):
wherein n is0Is the refractive index of air; n is the refractive index of photosensitive glue used for preparing the curved fly-eye lens; r is the curvature radius of the spherical crown of the curved fly-eye lens; h is0Is the sagittal height of the spherical cap of the sub-eye lens.
2. The method for designing and manufacturing a multi-focal curved fly-eye lens according to claim 1, wherein: the step S120 specifically includes: and coating an adhesive on the substrate in a spin coating manner, then coating photoresist, uniformly distributing the photoresist on the substrate by utilizing high-speed centrifugation, and then carrying out prebaking to obtain the photoresist mask with the micro-lens array.
3. The method for designing and manufacturing a multi-focal curved fly-eye lens according to claim 2, wherein: the step S130 specifically includes: and carrying out ICP etching on the part, which is not attached with the photoresist mask, on the substrate to obtain the microlens array with the same pattern as the photoresist mask.
4. The method for designing and manufacturing a multi-focal curved fly-eye lens according to claim 3, wherein: in step S140, the specific process of performing passivation is as follows:
soaking the etched substrate in an acetone solution to preliminarily remove the photoresist on the substrate;
mixing concentrated sulfuric acid and hydrogen peroxide according to the weight ratio of 3: 1, preparing a solution by mixing, putting the substrate into the solution, boiling, and removing the residual photoresist and part of impurities;
cleaning the sulfuric acid on the substrate by using clear water;
by C4F8And passivating the silicon wafer substrate, and forming a passivation layer on the surface of the silicon wafer.
5. The method for designing and manufacturing a multi-focal curved fly-eye lens according to claim 4, wherein: the step S150 specifically includes: placing a silicon wafer substrate with a micro-lens array in a mould, laying a polymer layer on the silicon wafer substrate, carrying out hot pressing treatment on the polymer layer at a glass transition temperature, and cooling and then peeling the polymer layer from the substrate to obtain the polymer micro-lens array.
6. The method for designing and manufacturing a multi-focal curved fly-eye lens according to claim 5, wherein: the step S160 specifically includes: placing the polymer micro-lens array in a mould, pouring PDMS (polydimethylsiloxane) pre-polymerization liquid, and placing the mould in a vacuum drying oven to be heated for a set time; and curing the PDMS pre-polymerization liquid to obtain a PDMS film with the microlens array pattern opposite to the polymer microlens array pattern.
7. The method for designing and manufacturing a multi-focal curved fly-eye lens according to claim 6, wherein: the step S170 specifically includes:
copying a micro-lens array on a PDMS film through an ultraviolet curing process, placing the PDMS film on a closed cavity, and deforming the PDMS film under the action of atmospheric pressure;
and pouring photosensitive adhesive into a concave spherical crown formed by the deformed film, placing a quartz glass sheet above the photosensitive adhesive, and curing under an ultraviolet lamp to obtain the designed curved fly-eye lens.
8. The method for designing and manufacturing a multi-focal curved fly-eye lens according to claim 5, wherein: the polymer layer includes COC, COP, PMMA, and PC.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010052554.1A CN111175861B (en) | 2020-01-17 | 2020-01-17 | Design and preparation method of multi-focal-length curved fly-eye lens |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010052554.1A CN111175861B (en) | 2020-01-17 | 2020-01-17 | Design and preparation method of multi-focal-length curved fly-eye lens |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111175861A CN111175861A (en) | 2020-05-19 |
| CN111175861B true CN111175861B (en) | 2021-06-15 |
Family
ID=70654674
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010052554.1A Active CN111175861B (en) | 2020-01-17 | 2020-01-17 | Design and preparation method of multi-focal-length curved fly-eye lens |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111175861B (en) |
Families Citing this family (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR102214328B1 (en) * | 2019-07-01 | 2021-02-15 | 주식회사 멤스룩스 | Diffuser having asymmetry type light output pattern and method for manufacturing thereof |
| CN112299363B (en) * | 2020-09-29 | 2024-03-19 | 江苏大学 | Preparation method of smooth inclined bottom surface microstructure array surface based on air die method |
| CN112225172B (en) * | 2020-09-29 | 2024-03-19 | 江苏大学 | Method for preparing near cylindrical surface micro-groove array surface based on air model method |
| CN112578484B (en) * | 2020-12-28 | 2021-12-07 | 中国科学院长春光学精密机械与物理研究所 | Non-uniform curved surface fly-eye lens and preparation method thereof |
| CN112649905B (en) * | 2020-12-28 | 2022-02-11 | 中国科学院长春光学精密机械与物理研究所 | Preparation method of fly-eye lens with free-form surface substrate |
| CN113156552A (en) * | 2021-04-22 | 2021-07-23 | 西北农林科技大学 | Method for manufacturing bifocal fly-eye lens with large field of view |
| CN113126188A (en) * | 2021-04-26 | 2021-07-16 | 中国科学院长春光学精密机械与物理研究所 | Curved fly-eye lens and preparation method thereof |
| CN113572932B (en) * | 2021-07-14 | 2022-05-27 | 吉林大学 | Photoelectric integrated miniature artificial compound eye camera and preparation method thereof |
| CN113897589A (en) * | 2021-10-09 | 2022-01-07 | 天津医科大学 | Preparation method of spatially-staggered mixed material film and application of spatially-staggered mixed material film in achromatic superlens |
| CN114296161A (en) * | 2021-12-28 | 2022-04-08 | 华中科技大学 | Large-area-array three-dimensional spherical micro-lens array and preparation method thereof |
| CN114355489B (en) * | 2022-01-13 | 2023-05-16 | 西华大学 | Curved fly-eye lens based on DMD digital lithography and preparation method thereof |
| CN115291306A (en) * | 2022-07-26 | 2022-11-04 | 武汉大学 | Preparation method of bionic compound eye structure with zooming performance |
| CN115857073B (en) * | 2023-02-06 | 2023-05-12 | 中国科学院长春光学精密机械与物理研究所 | Diaphragm array of multi-focal-length curved-surface micro-lens array and preparation method thereof |
| CN116224476B (en) * | 2023-03-22 | 2024-03-08 | 苏州汉骅半导体有限公司 | Microlens array and method for manufacturing same |
| CN116577855B (en) * | 2023-07-13 | 2023-10-03 | 中国科学院长春光学精密机械与物理研究所 | Double-glued fly-eye lens with diaphragm and preparation method thereof |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105425324A (en) * | 2015-12-17 | 2016-03-23 | 沈阳理工大学 | Manufacturing and imaging analysis of non-uniform curved microlens array |
| CN105467477A (en) * | 2015-12-03 | 2016-04-06 | 中国科学院长春光学精密机械与物理研究所 | Curved-surface bionic compound eye imaging device for zoom lens array |
| CN108663730A (en) * | 2018-05-09 | 2018-10-16 | 中国科学院长春光学精密机械与物理研究所 | A kind of preparation method for the fly's-eye lens that curvature is controllable |
| CN109243662A (en) * | 2018-09-14 | 2019-01-18 | 复旦大学 | The preparation method of hanging thick golden zone plate lens without substrate supports |
| CN110488396A (en) * | 2019-08-02 | 2019-11-22 | 北京理工大学 | It is a kind of for reducing the imaging method of parallel type bionic compound eyes off-axis aberration |
-
2020
- 2020-01-17 CN CN202010052554.1A patent/CN111175861B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105467477A (en) * | 2015-12-03 | 2016-04-06 | 中国科学院长春光学精密机械与物理研究所 | Curved-surface bionic compound eye imaging device for zoom lens array |
| CN105425324A (en) * | 2015-12-17 | 2016-03-23 | 沈阳理工大学 | Manufacturing and imaging analysis of non-uniform curved microlens array |
| CN108663730A (en) * | 2018-05-09 | 2018-10-16 | 中国科学院长春光学精密机械与物理研究所 | A kind of preparation method for the fly's-eye lens that curvature is controllable |
| CN109243662A (en) * | 2018-09-14 | 2019-01-18 | 复旦大学 | The preparation method of hanging thick golden zone plate lens without substrate supports |
| CN110488396A (en) * | 2019-08-02 | 2019-11-22 | 北京理工大学 | It is a kind of for reducing the imaging method of parallel type bionic compound eyes off-axis aberration |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111175861A (en) | 2020-05-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111175861B (en) | Design and preparation method of multi-focal-length curved fly-eye lens | |
| CN113126188A (en) | Curved fly-eye lens and preparation method thereof | |
| US8416498B2 (en) | Master model of lens array and method of manufacturing the same | |
| US8432625B2 (en) | Lens and method for manufacturing same | |
| US9184199B2 (en) | Optical assembly including plenoptic microlens array | |
| US8303866B2 (en) | Mass production of micro-optical devices, corresponding tools, and resultant structures | |
| US8611026B2 (en) | Optical device including at least one replicated surface and associated methods | |
| KR100541027B1 (en) | Image sensor, fabrication method of an image sensor and mold for fabricating a micro condenser element array used in the same | |
| CN103913784A (en) | Method for preparing polymer micro lens array | |
| CN112578484B (en) | Non-uniform curved surface fly-eye lens and preparation method thereof | |
| WO2008062836A1 (en) | Optical waveguide module and method for manufacturing the same | |
| CN112649905B (en) | Preparation method of fly-eye lens with free-form surface substrate | |
| US20120140340A1 (en) | Lens and method for manufacturing same | |
| WO2001069316A1 (en) | Exposure controlling photomask and production method therefor | |
| CN116577855B (en) | Double-glued fly-eye lens with diaphragm and preparation method thereof | |
| CN114355489B (en) | Curved fly-eye lens based on DMD digital lithography and preparation method thereof | |
| CN110780365A (en) | Method for manufacturing micro-lens array by photoetching and electroforming process | |
| JPH0570944B2 (en) | ||
| CN114280706B (en) | Preparation method of double-photoresist micro-array lens based on UV laser direct writing photoetching | |
| Voelkel et al. | Fabrication of aspherical microlenses in fused silica and silicon | |
| TW200819789A (en) | Molding technology of optics component with micro-lens array | |
| Hsieh et al. | A novel boundary-confined method for microlens arrays fabrication | |
| Yu et al. | Self-alignment Micro-lens by Gradient of Surface Tension | |
| CN114895389A (en) | Method for flexibly manufacturing multi-focus micro-lens array structure | |
| JP2004358559A (en) | Method of manufacturing article with fine surface structure, and die and method of manufacturing the same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |