CN111399092A

CN111399092A - Silicon wafer template for preparing micro-lens array structure, preparation method of micro-lens array structure and protective film

Info

Publication number: CN111399092A
Application number: CN202010129950.XA
Authority: CN
Inventors: 巫金波; 丁叶凯; 温维佳; 薛厂; 张萌颖; 林银银
Original assignee: Beijing Transpacific Technology Development Ltd
Current assignee: Beijing Transpacific Technology Development Ltd; University of Shanghai for Science and Technology
Priority date: 2020-02-28
Filing date: 2020-02-28
Publication date: 2020-07-10
Anticipated expiration: 2040-02-28
Also published as: CN111399092B

Abstract

The invention provides a preparation method of a silicon wafer template for preparing a micro-lens array structure, which comprises the steps of modifying a silicon wafer to enable the surface of the silicon wafer to have non-wettability, preparing circular patterns in array arrangement on the surface of the non-wetting silicon wafer to form a patterned surface, coating SU8 photoresist on the patterned surface to form an SU8 photoresist liquid drop array, exposing by ultraviolet light, and heating at 95 ℃ to obtain the silicon wafer template with a solidified SU8 convex lens array. The invention also provides a preparation method of the micro-lens array structure by utilizing the silicon wafer template and a protective film containing the micro-lens array. The preparation method of the silicon wafer template is simple, and the prepared silicon wafer template can be repeatedly utilized, so that the preparation cost can be reduced.

Description

Silicon wafer template for preparing micro-lens array structure, preparation method of micro-lens array structure and protective film

Technical Field

The invention relates to the technical field of microfluidics, in particular to a preparation method of a silicon wafer template for preparing a micro-lens array structure, and also relates to a preparation method of the micro-lens array structure and a protective film containing a micro-lens array.

Background

Microlens arrays (M L As) are arrays composed of lenses with micron-sized clear aperture and relief depth, and can be divided into two types, namely refractive microlens arrays and diffractive microlens arrays, which not only have the basic functions of focusing, imaging and the like of traditional lenses, but also have the characteristics of small unit size and high integration level, so that the microlens arrays can complete the functions which cannot be completed by traditional optical elements, and can form a plurality of novel optical systems, which can be widely applied to various systems such As wavefront sensing, light energy gathering, light shaping and the like As functional elements.

At present, the processing methods for microlens arrays mainly include diamond cutting, compression molding, inkjet printing, droplet methods, ion exchange lithography, and photoresist hot-melt methods, low-energy electron beam projection lithography, step etching, laser direct writing, electron beam direct writing, thin film deposition, and gray scale masking. In addition to the above methods, there are also some special processing methods such as ion etching, melt surface tension, holography, etc.

The processing method can process the microstructure surface with specific structure size, but the existing processing method has complex processing procedure, long period and low forming efficiency, has certain defects in the aspects of processing shape precision, surface quality control, preparation cost, efficiency and the like, and is difficult to prepare lenses with different curvatures at the same time in high flux, thereby limiting the further development and application of the microlens array.

Disclosure of Invention

In view of the above, the present invention is directed to a method for preparing a silicon wafer template for preparing a microlens array structure, which can be used for preparing the microlens array structure and overcome at least one of the deficiencies in the prior art.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

a method for preparing a silicon wafer template for preparing a micro-lens array structure comprises the following steps:

a. modifying the silicon wafer to enable the surface of the silicon wafer to have non-wettability;

b. preparing circular patterns in array arrangement on the surface of the non-wetting silicon wafer to form a patterned surface;

c. coating SU8 photoresist on the patterned surface to form an SU8 photoresist drop array;

d. and exposing by ultraviolet light, and heating at 95 ℃ to obtain the silicon wafer template with the cured SU8 convex lens array.

Further, in the step a, 1H,2H, 2H-perfluorooctyltriethoxysilane is used for modifying the silicon wafer, in the step b, a circular pattern is prepared on the surface of the non-wetting silicon wafer through a photoetching technology, and in the step d, the ultraviolet exposure time is 2s, and the heating is carried out for 90s at the temperature of 95 ℃.

Further, in the prepared pattern arranged in the array, the size of the pattern at each position is the same, or the patterns have a size gradient along an arrangement direction thereof, or the size of the pattern at least one position is different from that at other positions.

Compared with the prior art, the invention has the following advantages:

the preparation method of the silicon wafer template can obtain the solidified SU8 convex lens array on the silicon wafer based on the micro-fluidic and size limitation effects of surface tension limitation, and can be used as a micro lens template to prepare a subsequent micro lens array structure. The preparation method has simple process, can realize the preparation of the high-flux lens structure, can adjust the size of the coating liquid drop, namely the size of the solidified convex lens by controlling the coating speed and the number of coating layers so as to adjust the structural parameters of the micro-lens array and meet the actual requirements, and meanwhile, the silicon wafer template prepared by the invention can be repeatedly utilized for many times, thereby reducing the preparation cost of the micro-lens array structure.

Meanwhile, the invention also provides a preparation method of the micro-lens array structure, which comprises the following steps of firstly preparing a silicon wafer template with a cured SU8 convex lens array by adopting the preparation method, and further comprising the following steps:

e. prepolymer of PDMS and curing agent were mixed as 10: 1, uniformly stirring, removing bubbles, pouring onto the silicon wafer template with the SU8 convex lens array, and placing at room temperature to fully spread and flatten PDMS;

f. and heating and curing at 60 ℃, and uncovering the poured PDMS to obtain a flexible PDMS micro-lens array which is a concave lens array.

Further, in the step e, the mixture is placed at room temperature for 12 hours, and in the step f, the mixture is heated and cured for 1 hour at the temperature of 60 ℃.

Further, the method for preparing the microlens array structure of the present invention further comprises the following steps:

g. carrying out hydrophobic treatment on the prepared flexible PDMS concave lens array;

h. prepolymer of PDMS and curing agent were mixed as 10: 1, uniformly mixing and stirring, removing bubbles, pouring the mixture on the concave side of the flexible PDMS concave lens array, and placing the mixture at room temperature to fully spread and flatten PDMS;

i. heating and curing at 60 ℃, and uncovering the poured PDMS to obtain the flexible PDMS convex lens array.

Further, the hydrophobic treatment in the step g comprises adding 1H,1H,2H, 2H-perfluorooctyltriethoxysilane into a container, placing the prepared flexible PDMS concave lens array into the container, and placing the container in an oven to be heated for 2H.

Further, in the step h, the mixture is placed at room temperature for 12 hours, and in the step i, the mixture is heated and cured at 60 ℃ for 1 hour.

The preparation method of the microlens array structure can greatly simplify the preparation process, does not need expensive and precise equipment in the whole preparation process, is simple to operate, and can easily realize the controllable preparation of the high-flux microlens structure.

In addition, the invention also provides a protective film containing the micro-lens array, wherein the protective film is provided with a film-shaped substrate layer, the micro-lens array is prepared on the substrate layer, the preparation method of the micro-lens array on the substrate layer comprises the steps of firstly preparing a silicon wafer template with a cured SU8 convex lens array by adopting the preparation method, heating the substrate layer to the glass transition temperature, then covering the silicon wafer template with the cured SU8 convex lens array, standing, and forming the micro-lens array on one surface of the substrate layer, wherein the micro-lens array is a concave lens array.

Further, the substrate layer adopts one of PET material, PVC material, PE material and PP material, just the substrate layer cover in the processing of standing 50-70mim after on the silicon chip template to the one side of substrate layer forms the concave lens array.

Further, in the substrate layer has the laminating of the one side of concave lens array has PET to leave the type membrane, in the another side coating of substrate layer has glue to the laminating has PET to leave the type membrane.

Further, the glue is one of silica gel, acrylic glue and PU glue.

The protective film can effectively improve the illumination effect of L ED equipment or the screen brightness of O L ED electronic products through the prepared micro-lens array structure, is beneficial to reducing the energy consumption of the equipment and has good use effect.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 is a schematic diagram illustrating the fabrication of a silicon wafer template according to a first embodiment of the present invention;

FIG. 2 is a schematic diagram of a microlens array structure according to a second embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a multi-layer SU8 microlens according to the second embodiment of the present invention;

FIG. 4 is a contact angle variation curve of SU8 microlenses with different sizes and numbers of layers according to example II of the present invention;

FIG. 5 is a diagram showing the difference in imaging of different numbers of concave lenses and different sizes in the second embodiment of the present invention (in which, the upper left is a single-layer concave lens imaging with a diameter of 50 μm, the upper right is a three-layer concave lens imaging with a diameter of 50 μm, the lower left is a single-layer concave lens imaging with a diameter of 100 μm, and the lower right is a three-layer concave lens imaging with a diameter of 100 μm);

FIG. 6 is a schematic refraction diagram of O L ED light at an air interface from PDMS without or with a microlens array according to a second embodiment of the present invention;

FIG. 7 is a graph showing the transmittance of pure PDMS and PDMS microlens arrays of different sizes according to the second embodiment of the present invention;

FIG. 8 is the emission spectrum of an O L ED panel with PDMS or PDMS-M L As film added thereto according to a second embodiment of the present invention;

FIG. 9 is a schematic view of a specific application of PDMS-M L As attached on the surface of a display panel according to an embodiment of the present invention.

Detailed Description

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

Example one

The embodiment relates to a method for preparing a silicon wafer template for preparing a micro-lens array structure, which is shown in fig. 1 and specifically comprises the following steps:

step a: modifying the silicon wafer to enable the surface of the silicon wafer to have non-wettability;

step b: preparing circular patterns in array arrangement on the surface of the non-wetting silicon wafer to form a patterned surface;

step c: coating SU8 photoresist on the patterned surface to form an SU8 photoresist drop array;

step d: and exposing by ultraviolet light, and heating at 95 ℃ to obtain the silicon wafer template with the cured SU8 convex lens array.

In the above preparation steps, 1H, 2H-Perfluorooctyltriethoxysilane (POTS) is preferably used to modify the silicon wafer in step a, and circular patterns are preferably prepared on the surface of the non-wetting silicon wafer by photolithography, and the pattern size can be accurately controlled by a mask in the photolithography process.

In this embodiment, for the patterns arranged in the array prepared by photolithography, the dimensions of the patterns at each position, that is, the dimension specification of each pattern, may be the same, and at this time, the imaging effect at each position in the microlens array prepared by the silicon wafer template may also be consistent.

However, as another exemplary arrangement, as shown in fig. 1, in this embodiment, for example, each pattern may have a size gradient along an arrangement direction thereof. At this time, the "size gradient" means that the diameter of the circular patterns increases or decreases along the above-mentioned arrangement direction, and for a specific preparation example of this embodiment, the diameter size of the circular patterns arranged in an array increases from 10 μm to 105 μm, and the number of patterns on the whole silicon wafer surface also reaches 476139.

Of course, according to different design requirements, in addition to the above-mentioned pattern having a size gradient along one direction, the embodiment may also enable the prepared pattern to adopt other dimension arrangement forms. It may for example be such that only one end position, or both end positions, or a middle position, or a position near the end/middle has one dimension, while the other positions have other dimensions, or it may also take other arbitrary size arrangements.

By making the pattern of the array arrangement have a size gradient or making the pattern scale different at different positions, the SU8 photoresist drop array formed by coating and the SU8 convex lens array obtained after curing will have the same size gradient or the same scale distribution. In this embodiment, by using different sizes of patterns, silicon templates with patterns of different sizes can be used to make the microlens array capable of controlling the size of the image and the brightness resolution, and the relationship between the patterns of different sizes and the image can be referred to the description in the second embodiment below.

By setting different pattern sizes, when the prepared micro-lens array is used for imaging or screen protection, selective imaging can be carried out, or selective brightness enhancement of the protective film can be realized, and the micro-lens array can be specifically adopted according to actual requirements. For example, in the whole image, for the place where the emphasis is needed, the microlens array with smaller size can be selected to make the image displayed at that place brighter and clearer, and the microlens array with larger size can be selected at other places correspondingly, or a size gradient along one direction can be selected, so that the effect of gradual change of definition can be obtained.

Of course, according to different specific design requirements, the size of the pattern array formed on the surface of the silicon wafer can be arranged differently, and besides the circular pattern as exemplified above, the pattern can also be designed into other shapes based on the configuration of the required microlens, and the modified design of these other shapes is the equivalent design of the circular shape of the present embodiment, and the present embodiment does not limit this.

In this embodiment, when the SU8 photoresist coating is performed, as an exemplary operation manner, for example, a glass brush is used, and a robot controls the position of the glass brush and drives the glass brush to move, during the specific coating, the SU8 photoresist solution is added between the glass brush and the silicon wafer, so that the solution is spread over the entire gap, and then the robot pulls the glass brush to drive the SU8 photoresist solution to slide on the surface of the patterned silicon wafer, so as to form the SU8 photoresist droplet array.

Of course, other operation forms can be adopted in the embodiment besides the above coating method to achieve the same coating effect. In addition, it should be noted that, in the preparation process of this embodiment, the exposure time of the ultraviolet light in step d may be specifically 2s, and the silicon wafer template having the cured SU8 convex lens array is obtained by heating at 95 ℃ for 90s after the exposure of the ultraviolet light in step d, and the heating at 95 ℃ may be performed in an oven.

The preparation of the silicon wafer template of the embodiment is based on the microfluidics of surface tension limitation and the size limitation effect, so that a cured SU8 convex lens array can be obtained on the silicon wafer, and the cured SU8 convex lens array can be further used as a micro lens template for preparing a micro lens array structure.

The specific application of the silicon wafer template prepared in this embodiment will be specifically described in the following second embodiment and third embodiment.

Example two

This embodiment relates to a method for preparing a microlens array structure, which includes first preparing a silicon wafer template having a cured SU8 convex lens array by the method of the first embodiment, and as shown in fig. 2, the method for preparing a microlens array structure of this embodiment further includes:

step e: prepolymer of PDMS and curing agent were mixed as 10: 1, uniformly stirring, removing bubbles, pouring onto the silicon wafer template with the SU8 convex lens array, and placing at room temperature to fully spread and flatten PDMS;

step f: and heating and curing at 60 ℃, and uncovering the poured PDMS to obtain a flexible PDMS micro-lens array which is a concave lens array.

The prepolymer and the curing agent of the PDMS are also called as the main agent and the curing agent in other terms, and after the prepolymer and the curing agent are uniformly mixed, the bubbles are generally removed by breaking the bubbles after floating to the surface by vacuum pumping.

In addition, in the preparation process of this embodiment, the step e is generally left at room temperature for 12h, and the step f is generally heated and cured at 60 ℃ for 1h, and then the PDMS is uncovered, and the heating can also be performed in an oven.

It should be noted that, in the preparation method of this embodiment, it is necessary to ensure that the platform on which the silicon wafer of the poured PDMS is located is horizontal when the PDMS is cured, otherwise, the thickness of the PDMS may be uneven, and the optical performance of the prepared microlens structure may be affected. Meanwhile, PDMS with different qualities can be poured according to needs, so that the design needs of different light transmission properties can be met.

In this embodiment, through the above preparation process, the prepared microlens structure is specifically a concave lens array, and at this time, if the microlens array structure of a convex lens array still needs to be prepared, the following steps should be further performed:

step g: carrying out hydrophobic treatment on the prepared flexible PDMS concave lens array;

arrangement h: prepolymer of PDMS and curing agent were mixed as 10: 1, uniformly mixing and stirring, removing bubbles, pouring the mixture on the concave side of the flexible PDMS concave lens array, and placing the mixture at room temperature to fully spread and flatten PDMS;

step i: heating and curing at 60 ℃, and uncovering the poured PDMS to obtain the flexible PDMS convex lens array.

In the above process of preparing the microlens of the convex lens array, step g may be to add 1H, 2H-perfluorooctyltriethoxysilane, and the amount of 1H, 2H-perfluorooctyltriethoxysilane added in a container is generally 10u L, although the amount of 1H, 2H-perfluorooctyltriethoxysilane may also be adjusted appropriately according to the amount of the flexible PDMS concave lens array.

In addition, the above step h is also performed at room temperature for 12h, and in step i, the PDMS is heated and cured at 60 ℃ for 1h, and then the poured PDMS is uncovered, so as to obtain the flexible PDMS lenticular lens array.

The fabrication of the microlens array structure of this embodiment will be further described with reference to specific fabrication processes and associated performance tests.

In the specific preparation, SU8 photoresist is SU 82005, but in addition, other types of photoresists such as SU 82000.5, SU 82002, etc. or other photosensitive substances can be used.

In the preparation of the silicon wafer template, an SU 82005 photoresist liquid drop array is formed on a silicon wafer by using a coating method, and the height and the volume of the formed liquid drops can be further adjusted by adjusting the coating speed, the size of a pattern (transverse adjustment) and the number of coating layers (longitudinal adjustment).

At this time, in order to verify the influence of the coating process on the formed droplets, three coating methods were used, the three coating speeds were 100mm/min, 50mm/min, and 50mm/min, respectively, and each exposure time was 2 seconds, and curing was performed by heating at 95 ℃ for 90 seconds. By three coating, the structure of the formed SU8 microlens is as shown in fig. 3, and it was found by inspection that the height of a droplet having a diameter of 10 μm was increased from 0.882 μm to 1.691 μm, the contact angle was increased from 19.96 ° to 37.37 °, and the height of a droplet having a diameter of 100 μm was increased from 3.44 μm to 7.469 μm, and the contact angle was increased from 7.8 ° to 17.49 °.

By detecting the contact angles of a plurality of droplet sizes under different coating layer numbers, a contact angle change curve of the SU8 microlens is drawn as shown in FIG. 4, and as can be seen from FIG. 4, in the range of 0-50 μm, the contact angle is obviously reduced along with the continuous increase of the droplet size, and the contact angle is in an exponential reduction trend. In the range of 50-100 μm, the contact angle decreases slowly with the increasing size of the liquid drop, and a plateau area is formed. By the phenomenon, the contact angle can be effectively regulated and controlled within a certain size range in practical preparation.

Since the curvature, the numerical aperture, and the focal length of the microlens have a profound influence on the optical performance thereof, the present embodiment can realize a wide range of adjustment thereof by adjusting the size of the droplet and the number of times of application.

As shown in table 1 below, in the lateral adjustment, when the diameter of the microlens is increased from 10 μm to 100 μm, the curvature, focal length, and numerical aperture of the first layer are changed from 68.4, 28.65, and 0.17 to 2.74, 715.87, and 0.07, respectively, and the curvature, focal length, and numerical aperture of the third layer are changed from 121.36, 16.16, and 0.31 to 5.84, 335.48, and 0.15, respectively. In the longitudinal adjustment, after three coats, the curvature of the lens with the diameter of 10 μm is increased from 68.4 to 121.36, the focal length is decreased from 28.65 to 16.16, the numerical aperture is increased from 0.17 to 0.31, the curvature of the lens with the diameter of 100 μm is increased from 2.74 to 5.84, the focal length is decreased from 715.87 to 335.48, and the numerical aperture is increased from 0.07 to 0.15. Thus, by controlling the coating parameters, lenses with different optical parameters can be obtained, thereby meeting different practical requirements.

TABLE 1 variation of the curvature, focal length and numerical aperture of microlenses with different number and size of layers

In this embodiment, the flexible PDMS convex lens and the flexible PDMS concave lens prepared by the above method can perform clear imaging, and since the object distance is much larger than 2 times of the focal length during imaging, the imaging is generally an inverted image.

As shown in fig. 5, generally, the image size increases gradually with the increase in size, the size of the image to be formed also changes with the increase in the number of coating layers, and the luminance resolution of the image also changes with the change in the size of the image to be formed. Specifically, as the number of coating layers increases, the size of the image formed is gradually reduced, which is mainly due to the change of the object distance, and the difference of the magnification or the reduction factor is measured in each case, and as a result, as shown in table 2 below, it is known that the reduction factor is reduced from 1300 to 154 when the diameter of the convex lens is increased from 10 μm to 100 μm.

As shown in Table 3 below, the diameter of the concave lens is increased from 10 μm to 100 μm, and the reduction factor is reduced from 1313 to 198. Thus, by controlling the size of the droplets formed by coating, adjustment of the imaging performance of the produced microlens can be achieved.

TABLE 2 three-layer convex lens reduction magnification

TABLE 3 three-layer concave lens reduction powers

In addition, taking the flexible PDMS microlens array structure of the concave lens array prepared by the preparation method of this embodiment as an example, the refractive state of the flexible PDMS microlens array structure and pure PDMS without the microlens array at the air interface to O L ED light is shown in fig. 6, and it can be seen from fig. 6 that the emergent light is increased after the concave lens array PDMS is used.

The transmittance of the microlens arrays with different diameters is measured As shown in FIG. 7, wherein BarePDMS represents pure PDMS without microlens array structure for reference, and the emission spectrum of the O L ED panel with the addition of pure PDMS and the use of PDMS microlens array (PDMS-M L As) film is measured As shown in FIG. 8. from FIG. 7, the transmittance is increased and the brightness of the O L ED device is improved due to the increased transmittance, while from FIG. 8, it can be seen that compared with pure PDMS, PDMS with microlens array structure has different effects on the brightness enhancement of the O L ED device, wherein the enhancement effect of PDMS-M L As with a diameter of 5 μ M is most obvious and the brightness enhancement is 116%.

In addition, fig. 9 is a schematic diagram of a specific application of the PDMS-M L As prepared in this embodiment when it is attached to the surface of a touch display screen, where the diameter of M L As is 5 μ M, and the inventors can see that the brightness of the corresponding portion of the display screen is increased by using the PDMS-M L As of this embodiment through the observation of the touch display screen.

In the method for preparing the microlens array according to the embodiment, the preparation of the microlens array structure can be simply and conveniently realized by adopting the silicon wafer template, the operation is simple, and expensive and precise equipment is not needed in the whole preparation process. Furthermore, when the size gradient design in the first embodiment is utilized, lenses with different sizes can be completed on the same substrate, thereby facilitating the screening of lenses with different parameters.

In addition, the preparation method of the embodiment can easily realize the controllable preparation of the high-flux microlens structure by using the silicon wafer template, the flux of the high-flux microlens structure can reach 375KHz at most, the preparation method is far beyond the existing microfluidic technology, and the application of the microlens array structure can be well promoted.

EXAMPLE III

The embodiment relates to a protective film containing a micro-lens array, which can be used for L ED lighting equipment and electronic products such as mobile phones, tablet computers, smart watches, displays and the like, so as to protect the light-emitting surface of the lighting equipment and the display screen of the electronic products and reduce or avoid external damage.

The protective film of the present embodiment has a film-like base material layer, and in addition to the base material layer, the protective film of the present embodiment naturally includes other functional layers such as release films attached to both surfaces of the base material layer, so as to realize different protective characteristics of the protective film, as compared with the currently and commonly used protective film such as a mobile phone screen. In addition, the main invention of the display screen protection screen of the embodiment is that the microlens array is prepared on the substrate layer, so that the light transmittance of the protection film can be increased, and the use effect of the device applying the protection film is further improved.

Specifically, the preparation method in the first embodiment is adopted to prepare the silicon wafer template with the cured SU8 convex lens array, the substrate layer is heated to the vitrification temperature and then covered on the prepared silicon wafer template with the cured SU8 convex lens array, and after standing for a period of time, a required microlens array is formed on one surface of the substrate layer, and the microlens array is also specifically a concave lens array.

As a preferred embodiment, for example, the substrate layer of this embodiment may be made of PET, and in this case, the glass transition temperature of the PET material is generally 85 ℃, and the time for standing after the substrate layer is covered on the silicon wafer template is generally between 50 and 70mim, and preferably 60 min.

In addition, as an example of the structure of the protective film of this embodiment corresponding to the substrate layer made of PET, in addition to the substrate layer containing the microlens array, the protective film structurally includes, for example, a PET release film attached to one surface of the substrate layer having the concave lens array, glue applied to the other surface of the substrate layer, and a PET release film attached via the glue, so that the above multilayer film structures together form a complete protective film product.

In this embodiment, the above-mentioned glue generally adopts current pressure-sensitive glue, like silica gel, acrylic glue and PU glue in one alright, and the PET substrate and the PET release film of this embodiment all adopt current commercial material alright, simultaneously, this embodiment the aforesaid also can go on in the oven to the heating of substrate layer.

In the protective film of the present embodiment, the base material layer may be made of PET (polyethylene terephthalate), but other materials commonly used for protective films may be used, and in this case, the base material layer may be made of one of PE (polyethylene), PVC (polyvinyl chloride), and PP (polypropylene). When adopting other materials, its glass transition temperature can be different according to specific material, and along with the difference of substrate layer material, other layers in the protection film structure need material requirement or design demand according to the material, adopt corresponding membrane material can.

As shown by the related verification results in the second embodiment, the protective film of the present embodiment can effectively improve the transmittance of L ED lighting devices or O L ED electronic products, and can improve the lighting effect or the screen brightness, thereby reducing the energy consumption of the devices, and especially being beneficial to the improvement of the cruising ability of the electronic products.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. A preparation method of a silicon wafer template for preparing a micro-lens array structure is characterized by comprising the following steps: the method comprises the following steps:

2. The method for manufacturing a microlens array as set forth in claim 1, wherein: in the step a, 1H,2H, 2H-perfluorooctyltriethoxysilane is used for modifying the silicon wafer, in the step b, a circular pattern is prepared on the surface of the non-wetting silicon wafer through a photoetching technology, in the step d, the ultraviolet exposure time is 2s, and the heating is carried out for 90s at the temperature of 95 ℃.

3. The method for manufacturing a microlens array as set forth in claim 1, wherein: in the prepared pattern arranged in the array, the size of the pattern at each position is the same, or the patterns have size gradient along the arrangement direction, or the size of the pattern at least one position is different from that at other positions.

4. A method for preparing a micro-lens array structure is characterized by comprising the following steps: the method comprises the steps of preparing a silicon wafer template with a cured SU8 convex lens array by the preparation method of any one of claims 1 to 3, and further comprises the following steps:

5. The method of manufacturing a microlens array structure according to claim 4, wherein: and (e) standing at room temperature for 12h, and heating and curing at 60 ℃ for 1h in the step f.

6. The method for manufacturing a microlens array structure according to claim 4 or 5, wherein: the method also includes the steps of:

7. The method of manufacturing a microlens array structure according to claim 6, wherein: and the hydrophobic treatment in the step g comprises the steps of adding 1H,1H,2H, 2H-perfluorooctyl triethoxysilane into a container, placing the prepared flexible PDMS concave lens array into the container, and placing the container into an oven to be heated for 2 hours.

8. The method for manufacturing a microlens array as set forth in claim 6, wherein: and in the step h, the mixture is placed at room temperature for 12h, and in the step i, the mixture is heated and cured for 1h at the temperature of 60 ℃.

9. A protective film comprising a microlens array, characterized in that: the protection film is provided with a film-shaped substrate layer, a micro lens array is prepared on the substrate layer, the preparation method of the micro lens array on the substrate layer comprises the steps of firstly adopting the preparation method of any one of claims 1 to 3 to prepare a silicon wafer template with a cured SU8 convex lens array, further comprising the step of heating the substrate layer to a glass transition temperature, covering the silicon wafer template with the cured SU8 convex lens array, standing, and forming the micro lens array on one surface of the substrate layer, wherein the micro lens array is a concave lens array.

10. The protective film containing a microlens array as set forth in claim 9, wherein: the substrate layer adopts one of PET material, PVC material, PE material and PP material, just the substrate layer cover in the processing of standing after silicon chip template is gone up 50-70mim to form the concave lens array in the one side of substrate layer.

11. The protective film containing a microlens array as set forth in claim 10, wherein: in the substrate layer has the one side laminating of concave lens array has PET to leave the type membrane, in the another side coating of substrate layer has glue to the laminating has PET to leave the type membrane.

12. The protective film containing a microlens array as set forth in claim 11, wherein: the glue is one of silica gel, acrylic glue and PU glue.