Roll-to-roll nanoimprint device and method

Abstract

The invention relates to a roll-to-roll nanoimprint device and method.The device comprises an imprint roller, a mold roller, an auxiliary imprint roller set and a demolding roller, the mold roller is matched with the imprint roller and the demolding roller at the roll inlet position and the roll outlet position respectively, and the mold roller is connected with a two-way air pump through an airflow regulator; the adsorption state of the mold roller is adjusted through a two-way air pump and an air flow adjuster to carry out positive and negative pressure gas auxiliary mold filling and demolding, the coining roller and the demolding roller are both connected with the air pump, and a UV curing module is arranged on the auxiliary coining roller set; the coining roller positive pressure and the mold roller negative pressure provide coining force at the coiling position, auxiliary mold filling and curing are carried out through the auxiliary coining roller set containing the UV curing module, the demolding roller negative pressure and the mold roller positive pressure at the coiling position provide demolding force, and the coining completed part is separated from the mold roller. Compared with the prior art, the mold filling height of the imprinting glue in the mold is effectively increased, the cured imprinting glue can be promoted to be completely demolded from the mold, and the processing quality of the nano imprinting process is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of nanoimprinting, and relates to a roll-to-roll nanoimprinting device and method. Background Art

[0002] Nanoimprinting is an advanced manufacturing technology for making micro-nanoscale patterns, which is widely used in aerospace, flexible electronics, optical devices and other fields. Compared with traditional photolithography technology, nanoimprinting has the advantages of high resolution, high output and low cost. Among them, roller nanoimprinting is the continuous imprinting of roller molds and substrates, including roll-to-roll nanoimprinting and roll-to-plane nanoimprinting. Compared with plane nanoimprinting, it has the advantage of large-area nanoimprinting.

[0003] According to the results of the patent survey, there are many types of mold roller designs for macro manufacturing processes and flat imprint demoulding technologies, but there are no reports on mold roller design patents for large-area roll-to-roll nanoimprinting. For the nanoimprinting process, the imprint filling process and the demoulding process directly affect the transfer quality of the nanostructure.

[0004] Among the existing related technologies, patent CN101909859A proposes a nano-imprinting mold roller that is easy to replace the mold roller. The elastic film in the fluid container expands and contracts to achieve loading and unloading and fixing of the mold roller, and maintain the uniform thickness of the transferred film, but it cannot provide positive and negative pressure at a specific position to promote imprinting and demolding, and has limitations. Patent CN101249938A discloses a pneumatic-based micro-nano-imprinting demolding structure, which forms a closed space through a polymer clamping cover, injects compressed gas through the demolding airway, and uses the isobaric principle of the fluid to promote the mold and polymer to separate smoothly, which can effectively avoid deformation of the polymer, but the structure is only applicable to flat imprinting and cannot improve the quality of imprinting filling. Patent CN110962450A discloses a roll-to-roll UV imprinting device and method for electric field force-assisted filling and demolding, which can reduce demolding defects and improve the filling quality, but after the UV glue is cured, the effect of the electric field force on demolding will be weakened, which has certain limitations. Patent CN113075859A discloses a negative pressure nanoimprinting device and its imprinting method, which are suitable for nanostructures with greater depth. It can quickly form a negative pressure vacuum environment to promote imprinting and filling, but it cannot effectively promote demolding. Patent CN116430670A proposes a demolding device for flat surface imprinting. By adjusting the vacuum pressure, the product is evenly stressed during demolding to improve quality. However, the design is limited to flat surface imprinting, and it is impossible to adjust the local positive and negative pressures to ensure the quality of imprinting and demolding at the same time. Patent CN211492476U discloses a nanoimprinting device that can be automatically demolded. During demolding, the joint movement of the support mechanism forms an angle between the soft mold and the substrate, which alleviates the influence of demolding force and adhesion force on the demolding process and improves the reuse rate of the soft mold. However, the mechanical peeling method may damage the nanostructure and is only suitable for roll-to-flat nanoimprinting equipment.

[0005] Patent CN102866582A discloses a nanoimprint device and method for high-brightness LED graphics. The device includes: a wafer stage, a vacuum chuck, a substrate, a UV-curable nanoimprint resist, etc. The mold is a thin-film elastic composite soft mold. The mold includes a graphic layer and a support layer. The graphic layer has the characteristics of water solubility, film structure, elasticity and high transparency. The mold is manufactured using a rolling printing process; the method includes: a pretreatment process; an imprinting process; a curing process; a demolding process; a post-treatment process; and the transfer of the imprinted pattern. However, the patent uses plane-to-plane imprinting, and the imprinting area is limited, so it cannot be applied to large-area imprinting; and the patent uses the pressure difference of the vacuum negative pressure environment to assist the filling and demolding process throughout the process. The conditions are relatively strict, and problems such as uneven imprinting force and demolding force are prone to occur, resulting in defects such as bubbles.

[0006] Patent CN105159029A discloses a device and method for large-area micro-nano patterning, the device includes: a frame, a workbench, a wafer carrier, a substrate, an imprinting material, a soft mold, a roller, an ultraviolet light source, an imprinting mechanism, a vacuum pipeline, and a pressure pipeline; the method includes: pretreatment; imprinting and curing; demolding; and post-treatment. However, the patent adopts roller-to-flat imprinting, and the soft mold is attached to the roller, which is a split type. Not only is the imprinting area limited, but the roller is also prone to displacement when adsorbing or flattening the mold, which will affect the quality of the nanostructure; and the purpose of the conversion of positive and negative pressure in the patent is to make the soft mold flatten or separate from the imprinting material, and the imprinting force and demolding force are provided by the roller line contact pressure, which does not play a role in assisting imprinting or demolding, and is not conducive to the filling and complete demolding of the structure.

[0007] In summary, the existing technology has certain limitations in roll-to-roll nanoimprinting equipment and process methods. In terms of technical routes, most of them use roller-to-plane or plane-to-plane imprinting, which cannot achieve large-area imprinting; in the imprint filling stage, the microstructure is difficult to fill completely, and there may be structural defects such as bubbles; in the demolding stage, there is a lack of a suitable separation method, and traditional mechanical stripping will make it difficult to completely demold the nanostructure, resulting in defects such as breakage and cracking of the nanostructure. Summary of the invention

[0008] The purpose of the present invention is to provide a roll-to-roll nanoimprinting device and method in order to overcome at least one defect of the above-mentioned prior art. The present invention effectively increases the filling height of the imprinting glue in the mold, and can also promote the complete demolding of the cured imprinting glue from the mold, thereby improving the processing quality of the nanoimprinting process.

[0009] The purpose of the present invention can be achieved by the following technical solutions:

[0010] One of the technical solutions of the present invention is to provide a roll-to-roll nanoimprinting device, which includes an imprinting roller, a mold roller, an auxiliary imprinting roller group and a demolding roller, wherein the mold roller cooperates with the imprinting roller and the demolding roller at the roll-in and roll-out locations, respectively, and the mold roller is connected to a two-way air pump through an air flow regulator, and the adsorption state of the mold roller is adjusted by the two-way air pump and the air flow regulator to perform positive and negative pressure gas-assisted filling and demolding, thereby improving the filling quality and demolding quality, and thus improving the transfer quality of the nanostructure, wherein the imprinting roller and the demolding roller are both connected to the air pump, and a UV curing module is arranged on the auxiliary imprinting roller group;

[0011] At the in-reel, the positive pressure of the embossing roller and the negative pressure of the mold roller provide embossing force, and the auxiliary embossing roller group containing the UV curing module is used for auxiliary filling and curing. At the reel, the negative pressure of the demoulding roller and the positive pressure of the mold roller provide demoulding force to separate the embossed part from the mold roller.

[0012] As a preferred technical solution, the airflow regulator is located on the side of the mold roller and is connected to the mold roller through a sealing ring to prevent the positive and negative pressure environments from being disturbed by external air pressure.

[0013] As a preferred technical solution, the device also includes a coating component, which includes a glue dispenser and a thickness adjustment roller. The embossed glue is supplied to the substrate film through the glue dispenser, the glue output at each position is adjusted according to the target structure, and the glue is applied by a distributed glue dripping method. The embossed glue is evenly coated on the substrate film through the thickness adjustment roller to a thickness below a certain level.

[0014] As a preferred technical solution, the thickness adjusting roller is provided in a pair, including a first thickness adjusting roller and a second thickness adjusting roller, the first thickness adjusting roller is provided above the substrate film, and the second thickness adjusting roller is provided below the substrate film, and the thickness of the embossed glue on the substrate film is adjusted by adjusting the distance between the pair of thickness adjusting rollers.

[0015] Furthermore, a gas pipeline and a driving module are arranged in the mold roller, the mold roller is connected to an airflow regulator through the gas pipeline, the airflow regulator is connected to a two-way air pump, and the mold roller is driven to rotate by the driving module.

[0016] Furthermore, a template area is distributed on the outer surface of the mold roller, and a mold suction hole area is distributed outside the template area. The template area transfers the nanostructure onto the substrate film. The mold suction hole area is connected to the gas pipeline of the mold roller for air flow to adjust the adsorption state of the mold roller.

[0017] Furthermore, the mold suction hole area and the template area are distributed in axial or circumferential intervals according to actual production requirements. When the molding target has high requirements for a large area, the axial distribution is selected, and when the molding target has high requirements for continuity, the circumferential distribution is selected.

[0018] Furthermore, the gas pipeline of the mold roller is connected to the mold suction hole area through a gas guide, and the gas guide is evenly distributed along the circumference of the cross section of the mold roller. Each gas guide has a corresponding airflow regulator to control the pressure in the gas guide, and the positive and negative pressures at various positions in the mold suction hole area are controlled by the corresponding bidirectional air pump according to the processing stage.

[0019] The gas guide cooperates with the air flow regulator to divide the mold suction hole area on the surface of the mold roller into two areas, namely the filling area and the demolding area, and the two areas have opposite air pressure properties; the two-way air pump is used to reverse the positive and negative pressure states of the corresponding control areas, and two are provided. Because the two areas belong to opposite air pressure states, the air flow regulator is used to divide the respective ranges of the positive and negative pressure areas on the mold roller and adjust the gas flow; the gas guide forms a continuous negative pressure in the mold suction hole area on the surface through the air flow regulator, and forms a negative pressure vacuum area in the filling area, so as to prevent the embossing glue from generating bubbles due to gas residue during the filling process, which is beneficial to improving the filling quality and the production of nanostructures with a larger aspect ratio, and realizing the pattern transfer of the template area on the mold roller; after the embossing glue is solidified, the demolding area on the mold roller covered with the transferred material is subjected to positive air pressure through the two-way air pump and the air flow regulator, and cooperates with the demolding roller and the tension adjustment roller to generate the required demolding force, promote the demolding process, and realize the non-destructive separation of the nanostructure;

[0020] The mold roller has different air pressure distributions in different areas. By designing the internal gas guide of the mold roller and adjusting the bidirectional air pump and the codable air flow regulator, the mold roller provides positive air pressure in the area where demolding is required and provides negative air pressure in the area where filling is required. After a working cycle, the regional functions are interchanged and the bidirectional air pump is reversed to achieve the positive and negative pressure conversion in the mold suction hole area on the mold roller.

[0021] Furthermore, the driving module adopts step-by-step embossing to ensure that the embossing glue can be fully filled in the negative pressure environment and the auxiliary embossing roller group during the moving process, thereby ensuring the structural quality; during the stopping process, the embossing glue can have sufficient time to be exposed to ultraviolet rays to ensure that the embossing glue is completely cured; the advantage of the step-by-step embossing process is that it can form stable periodic production and improve the quality and efficiency of transfer.

[0022] Furthermore, an embossing suction hole area is distributed on the outer surface of the embossing roller, and the embossing suction hole area is connected to an air pump through a gas pipeline to provide positive pressure, and cooperates with the negative pressure of the mold roller to provide basic embossing force;

[0023] The outer surface of the demoulding roller is provided with a demoulding suction hole area, which is connected to the air pump through a gas pipeline to provide negative pressure, and cooperates with the positive pressure of the mold roller to provide basic demoulding force, so as to promote the complete demoulding of the solidified embossing glue from the mold and improve the demoulding quality.

[0024] As a preferred technical solution, the embossing roller is a flexible roller, which can adapt to the unevenness of the substrate film and improve the embossing quality.

[0025] Furthermore, the auxiliary embossing roller group includes an auxiliary embossing roller, a hydraulic press and a support frame, and a plurality of auxiliary embossing rollers and a UV curing module are arranged on the support frame at the same intervals along the circumference of the support frame, and the UV curing modules are equidistantly distributed between the auxiliary embossing rollers. The distance between the auxiliary embossing roller group and the mold roller is adjusted by the hydraulic press according to the processing stage.

[0026] As a preferred technical solution, the UV curing module includes a high-pressure mercury lamp UV (ultraviolet) lamp or a UV-LED (ultraviolet-light-emitting diode) curing light source.

[0027] As a preferred technical solution, the auxiliary embossing rollers are arranged at the same interval along the circumference of the support frame through hinges, universal joints or ball bearings.

[0028] As a preferred technical solution, the hydraulic presses are respectively located at two ends of the support frame.

[0029] Furthermore, the shape of the support frame is arc-shaped and fits the curve of the mold roller. The distance between the auxiliary embossing roller and the support frame decreases along the circumference of the support frame from the winding point to the winding point to ensure that the auxiliary embossing roller fits the mold roller in sequence, thereby avoiding interference between the embossing and filling process of the next cycle and the demolding process of the previous cycle.

[0030] As a preferred technical solution, the auxiliary embossing roller is connected to the support frame via an elastic member, and the elastic member adopts a combined structure of a spring and a damper to provide an adaptive embossing force load.

[0031] As a preferred technical solution, the structure of the auxiliary embossing roller group includes a roller type or a crawler type to meet different production requirements.

[0032] During the filling process, it is the first stepping stage, the UV curing module is closed, and the auxiliary embossing roller group is driven by the hydraulic device, and sequentially fits the mold roller according to the corresponding position starting from the roll-in, provides positive pressure, assists in filling, and ensures complete filling; because the filling stage starts from the roll-in, and the reel is demoulding at this time, the sequential fitting can ensure that the positive pressure is first provided to the filled part of the roll-in during the stepping process, and at the same time, no force is applied to the demoulding of the reel, so as to avoid the mutual interference between the embossing filling process of the next cycle and the demoulding process of the previous cycle; after the filling is completed, it enters the second stepping stage, the device stops rotating, the UV curing module is started, and the embossing glue is cured; after the curing is completed, the auxiliary embossing roller group is separated from the mold roller by the hydraulic device to avoid interfering with the demoulding process, and prepares for the next cycle of stepping embossing process.

[0033] As a preferred technical solution, the device also includes a tension adjustment roller, which is covered with an imprinted substrate film and drives the demoulding and winding together with the demoulding roller, and the tension is adjusted by adjusting the distance between the demoulding roller and the tension adjustment roller.

[0034] As a preferred technical solution, a pair of tension adjustment rollers are provided, including a first tension adjustment roller and a second tension adjustment roller. The first tension adjustment roller allows the printed substrate film to be pulled out horizontally from behind the demolding roller, and the second tension adjustment roller allows the printed substrate film to be pulled out vertically from behind the first tension adjustment roller and change the winding direction.

[0035] One of the technical solutions of the present invention is to provide a roll-to-roll nanoimprinting method, which uses the above-mentioned device to perform nanostructure imprinting, and the method comprises the following steps:

[0036] S1, coating process, the embossing glue is evenly spread on the surface of the substrate film;

[0037] S2, during the filling process, when the coated substrate film enters the embossing roller area, the embossing roller and the mold roller are close to each other to generate an embossing force; at this time, the embossing roller continuously inputs positive air pressure, and the mold roller in contact with the substrate film continuously provides negative air pressure to ensure a negative pressure environment during filling; as the filling progresses, the auxiliary embossing roller group sequentially fits the mold roller according to the corresponding position to provide positive pressure to ensure that the filling is completed smoothly;

[0038] S3, curing process, when the auxiliary embossing roller group is in full contact with the filled substrate film, the UV curing process begins; at this time, the overall displacement of the device remains unchanged, and the UV curing module located on the auxiliary embossing roller group is started until the embossing glue is completely cured to achieve the transfer of the nanostructure;

[0039] S4, demoulding process, after the nanostructure transfer is completed, the auxiliary embossing roller group moves away from the mold roller; the area of ​​the mold roller covered with the transferred substrate film is subjected to positive air pressure through a two-way air pump and an air flow regulator, so that the substrate film with the nanostructure is initially separated from the mold roller; then the device is started, and the demoulding roller provides negative air pressure, which cooperates with the mold roller to generate a demoulding force, so that the substrate film is completely separated from the mold roller; at the same time, the substrate film that enters later enters a new filling cycle;

[0040] S5, winding process, after the demoulding process is completed, a periodic nanostructure is formed on the substrate film, and the demoulding and winding are completed under the action of the winding roller.

[0041] As a preferred technical solution, the spacing between the thickness adjustment rollers is adjusted in advance before embossing begins, and the embossing roller, the mold roller, the auxiliary embossing roller group and the demoulding roller all work at the same linear speed.

[0042] As a preferred technical solution, the embossing glue includes photocurable polyacrylic resin, photocurable polyurethane acrylate or photocurable epoxy resin, which can be cured under the irradiation of a UV curing module to smoothly transfer the nanostructure. The material of the substrate film includes polyethylene terephthalate (PET), polycarbonate (PC) or thermoplastic polyurethane elastomer (TPU) substrate.

[0043] As a preferred technical solution, the device performs the pre-curing process at a slower speed.

[0044] As a preferred technical solution, demoulding and winding are completed under the action of a tension regulating roller and a winding roller.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] (1) In the present invention, during the filling process, the mold roller provides a negative pressure environment, and the embossing roller and the auxiliary embossing roller group provide embossing force, which effectively increases the filling height of the embossing glue in the mold, solves the problems of insufficient filling of the nanostructure and bubbles during the filling process, and improves the filling quality of large-area nanostructures in the roll-to-roll nanoimprinting process;

[0047] (2) In the demolding process of the present invention, the mold roller provides a positive pressure environment, and the demolding roller provides a demolding force, so that the cured imprinting adhesive is completely demolded from the mold, thereby solving the problems of nanostructure fracture and cracking during the demolding process, and improving the demolding quality of large-area nanostructures in the roll-to-roll nanoimprinting process;

[0048] (3) The transfer process of the present invention is an adjustable step-by-step process, which ensures that the imprint glue is fully cured and completely transferred during the filling process. At the same time, it has strong adjustability and integration, and cooperates with the innovative design of positive and negative pressure to improve the transfer quality of large-area roll-to-roll nanoimprinting process. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 Schematic diagram of the structure of a roll-to-roll nanoimprinting device in an embodiment of the present invention;

[0050] Figure 2 It is a schematic structural diagram of the circumferentially distributed mold rollers in an embodiment of the present invention;

[0051] Figure 3 It is a schematic structural diagram of the axially distributed mold roller in an embodiment of the present invention;

[0052] Figure 4 Schematic diagram of the structure of the embossing roller and the demoulding roller in the embodiment of the present invention;

[0053] Figure 5 3 is a scanning electron microscope (SEM) image of the moth-eye nanoarray structure in an embodiment of the present invention.

[0054] Description of the markings in the figure:

[0055] 1—glue dispenser, 2—first thickness adjustment roller, 3—second thickness adjustment roller, 4—substrate film, 5—embossing roller, 511—embossing suction hole area, 6—mold roller, 611—mold suction hole area, 612—template area, 7—auxiliary embossing roller group, 701—auxiliary embossing roller, 702—UV curing module, 703—hydraulic press, 704—support frame, 8—mold release roller, 811—mold release suction hole area, 9—first tension adjustment roller, 10—second tension adjustment roller. DETAILED DESCRIPTION

[0056] The present invention is described in detail below in conjunction with specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and a specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0057] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", "third", etc. are used to describe common objects, which only refer to different instances of the same object, and are not intended to imply that the objects described in this way must adopt a given order, whether in time, space, order or any other way.

[0058] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0059] Example:

[0060] A roll-to-roll nanoimprinting device, such as Figure 1As shown, it includes an embossing roller 5, a mold roller 6, an auxiliary embossing roller group 7 and a demoulding roller 8. The mold roller 6 cooperates with the embossing roller 5 and the demoulding roller 8 at the winding position and the reeling position respectively. The mold roller 6 is connected to a two-way air pump through an air flow regulator. The adsorption state of the mold roller 6 is adjusted by the two-way air pump and the air flow regulator to perform positive and negative pressure gas-assisted filling and demoulding, so as to improve the filling quality and demoulding quality, thereby improving the transfer quality of the nanostructure. The embossing roller 5 and the demoulding roller 8 are both connected to the air pump, and a UV curing module 702 is arranged on the auxiliary embossing roller group 7;

[0061] In this embodiment, the maximum pressure that the (bidirectional) air pump can provide is 0.1 MPa, and the maximum power of the UV curing module 702 is 200 mW / cm 2 ;

[0062] At the in-rolling position, the embossing roller 5 is under positive pressure and the mold roller 6 is under negative pressure to provide embossing force, and the auxiliary embossing roller group 7 containing the UV curing module 702 is used to assist in filling and curing. At the rewinding position, the demoulding roller 8 is under negative pressure and the mold roller 6 is under positive pressure to provide demoulding force, so as to separate the embossed part from the mold roller 6;

[0063] The airflow regulator is located on the side of the mold roller 6 and is connected to the mold roller 6 through a sealing ring to prevent the positive and negative pressure environment from being disturbed by the external air pressure;

[0064] The device also includes a coating component, which includes a glue dispenser 1 and a thickness adjustment roller. The glue dispenser 1 supplies the embossed glue to the substrate film 4, and the glue output at each position is adjusted according to the target structure. The glue is applied by a distributed glue dripping method. The embossed glue is evenly coated on the substrate film 4 by the thickness adjustment roller to a thickness of less than 5 μm.

[0065] A pair of thickness adjusting rollers are provided, including a first thickness adjusting roller 2 and a second thickness adjusting roller 3. The first thickness adjusting roller 2 is provided above the substrate film 4, and the second thickness adjusting roller 3 is provided below the substrate film 4. The thickness of the embossed rubber on the substrate film 4 is adjusted by adjusting the distance between the pair of thickness adjusting rollers.

[0066] A gas pipeline and a driving module are arranged inside the mold roller 6. The mold roller 6 is connected to the air flow regulator through the gas pipeline. The air flow regulator is connected to the two-way air pump. The mold roller 6 is driven to rotate by the driving module.

[0067] like Figure 2 and Figure 3 As shown, the outer surface of the mold roller 6 is distributed with a template area 612, and a mold suction hole area 611 is distributed outside the template area 612. The template area 612 transfers the nanostructure onto the substrate film 4, and the mold suction hole area 611 is connected to the gas pipeline of the mold roller 6 for air flow to adjust the adsorption state of the mold roller 6;

[0068] In this embodiment, the template area 612 is an anodized aluminum template coated on the surface of the mold roller 6, and the surface characteristic structure of the anodized aluminum template is a nano-random microporous array structure. The pore depth of the nano-random microporous array structure is 50-500nm, and preferably 350nm in this embodiment;

[0069] The mold suction hole area 611 and the template area 612 are distributed in an axial or circumferential interval according to actual production requirements. When the molding target has a high requirement for a large area, the axial distribution is selected, and when the molding target has a high requirement for continuity, the circumferential distribution is selected. In this embodiment, for the moth-eye nanoarray structure, there is a high requirement for continuity, and the circumferentially distributed mold roller 6 design is used for nanostructure transfer;

[0070] The gas pipeline of the mold roller 6 is connected to the mold suction hole area 611 through the gas guide, and the gas guide is evenly distributed along the cross-section circumference of the mold roller 6. Each gas guide has a corresponding air flow regulator to control the pressure in the gas guide. The positive and negative pressures at each position of the mold suction hole area 611 are controlled by the corresponding bidirectional air pump according to the processing stage.

[0071] The gas guide cooperates with the air flow regulator to divide the mold suction hole area 611 on the surface of the mold roller 6 into two areas, namely the filling area and the demolding area, and the two areas have opposite air pressure properties; the two-way air pump is used to reverse the positive and negative pressure states of the corresponding control areas, and two are provided. Because the two areas belong to opposite air pressure states, the air flow regulator is used to divide the respective ranges of the positive and negative pressure areas on the mold roller 6 and adjust the gas flow; the gas guide can form a continuous negative pressure in the mold suction hole area 611 on the surface through the air flow regulator, and form a negative pressure vacuum area in the filling area, which can prevent the embossing glue from generating bubbles due to gas residue during the filling process, which is beneficial to improving the filling quality and the production of nanostructures with a larger aspect ratio, and can better realize the pattern transfer of the template area 612 on the mold roller 6; after the embossing glue is solidified, the demolding area on the mold roller 6 covered with the transferred material is subjected to positive air pressure through the two-way air pump and the air flow regulator, and cooperates with the demolding roller 8 and the tension adjustment roller to generate the required demolding force, promote the demolding process, and realize the non-destructive separation of the nanostructure;

[0072] The air pressure distribution of the mold roller 6 is different in different areas; by designing the internal air guide of the mold roller 6 and adjusting the two-way air pump and the coded air flow regulator, the mold roller 6 can provide positive air pressure in the area where demolding is required and negative air pressure in the area where filling is required; after a working cycle, the regional functions are interchanged and the two-way air pump is reversed to achieve the positive and negative pressure conversion of the mold suction hole area 611 on the mold roller 6;

[0073] The driving module adopts step-by-step embossing to ensure that the embossing glue can be fully filled in the negative pressure environment and the auxiliary embossing roller group 7 during the moving process, thereby ensuring the structural quality; during the stopping process, the embossing glue can be exposed to ultraviolet rays for a sufficient time to ensure that the embossing glue is completely cured; the advantage of the step-by-step embossing process is that it can form a stable periodic production and improve the quality and efficiency of the transfer;

[0074] like Figure 4 As shown, the outer surface of the embossing roller 5 is distributed with an embossing suction hole area 511, which is connected to the air pump through a gas pipeline to provide positive pressure, and cooperates with the negative pressure of the mold roller 6 to provide basic embossing force. At the same time, the embossing roller 5 uses a flexible roller, which can adapt to the unevenness of the substrate film 4 and improve the embossing quality;

[0075] The outer surface of the demoulding roller 8 is provided with a demoulding suction hole area 811, which is connected to an air pump through a gas pipeline to provide negative pressure, and cooperates with the mold roller 6 to provide a basic demoulding force, so as to facilitate the complete demoulding of the solidified embossing glue from the mold, thereby improving the demoulding quality;

[0076] The auxiliary embossing roller group 7 includes an auxiliary embossing roller 701, a hydraulic press 703 and a support frame 704. A plurality of auxiliary embossing rollers 701 and UV curing modules 702 are arranged on the support frame 704. The auxiliary embossing rollers 701 are arranged at the same interval along the circumference of the support frame 704. The UV curing modules 702 are equidistantly distributed between the auxiliary embossing rollers 701. The distance between the auxiliary embossing roller group 7 and the mold roller 6 is adjusted by the hydraulic press 703 according to the processing stage.

[0077] The UV curing module 702 includes a high-pressure mercury UV (ultraviolet) lamp or a UV-LED (ultraviolet-light-emitting diode) curing light source, and in this embodiment, a high-pressure mercury UV lamp is preferably used;

[0078] The auxiliary embossing rollers 701 are arranged at the same interval along the circumference of the support frame 704 by hinges, universal joints or ball bearings, and in this embodiment, hinges are preferred;

[0079] The hydraulic devices 703 are respectively located at both ends of the support frame 704;

[0080] The shape of the support frame 704 is an arc shape and fits the curve of the mold roller 6. The distance between the auxiliary embossing roller 701 and the support frame 704 decreases along the circumference of the support frame 704 from the winding position to the winding position, so as to ensure that the auxiliary embossing roller 701 fits the mold roller 6 in sequence, thereby avoiding the mutual interference between the embossing filling process of the next cycle and the demoulding process of the previous cycle;

[0081] The auxiliary embossing roller 701 is connected to the support frame 704 through an elastic member, and the elastic member adopts a combination structure of a spring and a damper to provide an adaptive embossing force load of a maximum of 0.1 MPa;

[0082] The auxiliary embossing roller set 7 may be of a roller type or a crawler type to meet different production requirements. In this embodiment, the auxiliary embossing roller set 7 adopts a roller type structure.

[0083] During the filling process, it is the first stepping stage, the UV curing module 702 is closed, and the auxiliary embossing roller group 7 is driven by the hydraulic device 703, starting from the leftmost end of the roll-in and sequentially fitting the mold roller 6 according to the corresponding position, providing positive pressure, assisting the filling process, and ensuring that the filling process is complete; because the filling process starts from the leftmost end of the roll-in, and the rightmost end of the roll-in is demoulding at this time, the sequential fitting can ensure that the positive pressure is first provided to the filled part of the left end of the roll-in during the stepping process, and at the same time, no force is applied to the demoulding of the right end of the roll-in, so as to avoid the interference between the next cycle of the embossing filling process and the previous cycle of the demoulding process; after the filling process is completed, it enters the second stepping stage, the device stops rotating, the UV curing module 702 is started, and the embossing glue is cured; after the curing is completed, the auxiliary embossing roller group 7 is separated from the mold roller 6 by the hydraulic device 703 to avoid interfering with the demoulding process, and prepares for the next cycle of the stepping embossing process;

[0084] The device also includes a tension regulating roller, on which the printed substrate film 4 is sleeved, and which drives the demoulding and winding together with the demoulding roller 8, and the tension is adjusted by adjusting the distance between the demoulding roller 8 and the tension regulating roller;

[0085] A pair of tension adjustment rollers are provided, including a first tension adjustment roller 9 and a second tension adjustment roller 10. The first tension adjustment roller 9 allows the printed substrate film 4 to be pulled out horizontally from behind the demoulding roller 8, and the second tension adjustment roller 10 allows the printed substrate film 4 to be pulled out vertically from behind the first tension adjustment roller 9 and change the winding direction.

[0086] A roll-to-roll nanoimprinting method uses the above device to perform nanostructure imprinting, and the specific steps are as follows:

[0087] Before embossing begins, the spacing of the thickness adjusting rollers is adjusted in advance, and the embossing roller 5, the mold roller 6, the auxiliary embossing roller group 7 and the demoulding roller 8 all work at the same linear speed;

[0088] A photocurable polyacrylic resin is selected from photocurable polyacrylic resin, photocurable polyurethane acrylate or photocurable epoxy resin as the embossing glue, which can be cured under the irradiation of the UV curing module 702 to smoothly transfer the nanostructure, and a PET substrate is selected from polyethylene terephthalate (PET), polycarbonate (PC) or thermoplastic polyurethane elastomer (TPU) substrate as the material of the substrate film 4;

[0089] S1, coating process, supplying embossed glue to the substrate film 4 through the glue dispenser 1, adjusting the glue output at each position according to the target structure, and applying glue by a distributed glue dripping method. The device performs a pre-curing process at a relatively slow speed. At the same time, the embossed glue is evenly spread on the surface of the substrate film 4;

[0090] S2, during the filling process, when the coated substrate film 4 enters the area of ​​the embossing roller 5, the embossing roller 5 and the mold roller 6 are close to each other, generating an embossing force; at this time, the embossing roller 5 continuously inputs positive air pressure, and the mold roller 6 in contact with the substrate film 4 continuously provides negative air pressure to ensure a negative pressure environment during filling; as the filling proceeds, the auxiliary embossing roller group 7 sequentially fits the mold roller 6 according to the corresponding positions (the left end of the roll-in first approaches the mold roller 6), providing positive pressure to ensure that the filling is completed smoothly;

[0091] S3, curing process, when the auxiliary embossing roller group 7 is completely in contact with the filled substrate film 4, the UV curing process begins; at this time, the overall displacement of the device remains unchanged, and the UV curing module 702 located on the auxiliary embossing roller group 7 is started until the embossing glue is completely cured to achieve the transfer of the nanostructure;

[0092] S4, demoulding process, after the nanostructure transfer is completed, the auxiliary embossing roller group 7 is away from the mold roller 6; the area of ​​the mold roller 6 covered with the transferred substrate film 4 is subjected to positive air pressure through a two-way air pump and an air flow regulator, so that the substrate film 4 with the nanostructure is initially separated from the mold roller 6; then the device is started, and the demoulding roller 8 provides negative air pressure, which cooperates with the mold roller 6 to generate a demoulding force, so that the substrate film 4 is completely separated from the mold roller 6; at the same time, the substrate film 4 that enters later enters a new filling cycle;

[0093] S5, winding process, after the demoulding process is completed, a periodic moth-eye nanoarray structure is formed on the substrate film 4, and demoulding and winding are completed under the action of the tension adjustment roller and the winding roller.

[0094] like Figure 5 As shown, under a scanning electron microscope (SEM), the micropore depth of the mold is 350nm, the height of the moth-eye structure obtained by imprinting is 300-350nm, and it has a regular array arrangement, which proves that the periodic moth-eye nanoarray structure is completed.

[0095] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A roll-to-roll nanoimprinting device, characterized in that: The device comprises an embossing roller (5), a mold roller (6), an auxiliary embossing roller group (7) and a demoulding roller (8); the mold roller (6) cooperates with the embossing roller (5) and the demoulding roller (8) at the reeling position and the reeling position respectively; the mold roller (6) is connected to a bidirectional air pump via an air flow regulator; the adsorption state of the mold roller (6) is adjusted via the bidirectional air pump and the air flow regulator to perform positive and negative pressure gas-assisted filling and demoulding; the embossing roller (5) and the demoulding roller (8) are both connected to the air pump; and a UV curing module (702) is arranged on the auxiliary embossing roller group (7); At the winding position, the embossing roller (5) is under positive pressure and the mold roller (6) is under negative pressure to provide embossing force, and auxiliary filling and curing are performed through an auxiliary embossing roller group (7) containing a UV curing module (702). At the winding position, the demoulding roller (8) is under negative pressure and the mold roller (6) is under positive pressure to provide demoulding force, thereby achieving separation of the embossed part from the mold roller (6).

2. The roll-to-roll nanoimprinting device according to claim 1, characterized in that: A gas pipeline and a driving module are arranged inside the mold roller (6); the mold roller (6) is connected to an air flow regulator via the gas pipeline; the air flow regulator is connected to a bidirectional air pump; and the mold roller (6) is driven to rotate via the driving module.

3. The roll-to-roll nanoimprinting device according to claim 2, characterized in that: The outer surface of the mold roller (6) is provided with a template area (612), and the outside of the template area (612) is provided with a mold suction hole area (611). The template area (612) transfers the nanostructure onto the substrate film (4), and the mold suction hole area (611) is connected to the gas pipeline of the mold roller (6) to allow air flow and adjust the adsorption state of the mold roller (6).

4. The roll-to-roll nanoimprinting device according to claim 3, characterized in that: The mold suction hole area (611) and the template area (612) are distributed at intervals in the axial direction or the circumferential direction.

5. The roll-to-roll nanoimprinting device according to claim 3, characterized in that: The gas pipeline of the mold roller (6) is connected to the mold suction hole area (611) through a gas guide, and the gas guide is distributed along the circumference of the cross section of the mold roller (6). Each gas guide has a corresponding air flow regulator to control the pressure in the gas guide, and the positive and negative pressures at various positions of the mold suction hole area (611) are controlled by a corresponding bidirectional air pump according to the processing stage.

6. The roll-to-roll nanoimprinting device according to claim 2, characterized in that: The driving module adopts step-by-step stamping.

7. The roll-to-roll nanoimprinting device according to claim 1, characterized in that: The outer surface of the embossing roller (5) is provided with an embossing hole area (511), and the embossing hole area (511) is connected to an air pump via a gas pipeline to provide positive pressure; The outer surface of the demoulding roller (8) is provided with a demoulding suction hole area (811), and the demoulding suction hole area (811) is connected to an air pump through a gas pipeline to provide negative pressure.

8. The roll-to-roll nanoimprinting device according to claim 1, characterized in that: The auxiliary embossing roller group (7) comprises an auxiliary embossing roller (701), a hydraulic press (703) and a support frame (704); a plurality of auxiliary embossing rollers (701) and UV curing modules (702) are arranged on the support frame (704); the auxiliary embossing rollers (701) are arranged at the same interval along the circumference of the support frame (704); the UV curing modules (702) are equidistantly distributed between the auxiliary embossing rollers (701); and the distance between the auxiliary embossing roller group (7) and the mold roller (6) is adjusted according to the processing stage by the hydraulic press (703).

9. The roll-to-roll nanoimprinting device according to claim 8, characterized in that: The support frame (704) is in an arc shape and fits the curve of the mold roller (6). The distance between the auxiliary embossing roller (701) and the support frame (704) decreases along the circumference of the support frame (704) from the winding point to the winding point.

10. A roll-to-roll nanoimprinting method, characterized in that: The method uses the device according to any one of claims 1 to 9 to perform nanostructure imprinting, and the method comprises the following steps: S1, coating process, spreading the embossing glue on the surface of the substrate film (4); S2, during the filling process, when the coated substrate film (4) enters the area of ​​the embossing roller (5), the embossing roller (5) and the mold roller (6) are close to each other to generate an embossing force; at this time, the embossing roller (5) continuously inputs positive air pressure, and the mold roller (6) in contact with the substrate film (4) continuously provides negative air pressure to ensure a negative pressure environment during filling; as the filling is carried out, the auxiliary embossing roller group (7) sequentially fits the mold roller (6) according to the corresponding positions to provide positive pressure to ensure that the filling is completed; S3, curing process, when the auxiliary embossing roller group (7) is completely in contact with the filled substrate film (4), the UV curing process begins; at this time, the overall displacement of the device remains unchanged, and the UV curing module (702) located on the auxiliary embossing roller group (7) is started until the embossing glue is completely cured, thereby achieving the transfer of the nanostructure; S4, demoulding process, after the nanostructure transfer is completed, the auxiliary embossing roller group (7) moves away from the mold roller (6); the area of ​​the mold roller (6) covered with the substrate film (4) after the transfer is completed is subjected to positive air pressure through a two-way air pump and an air flow regulator, so that the substrate film (4) with the nanostructure is initially separated from the mold roller (6); then the device is started, and the demoulding roller (8) provides negative air pressure, which cooperates with the mold roller (6) to generate a demoulding force, so that the substrate film (4) is completely separated from the mold roller (6); at the same time, the substrate film (4) that enters subsequently enters a new filling cycle; S5, winding process, after the demoulding process is completed, a periodic nanostructure is formed on the substrate film (4), and demoulding and winding are completed under the action of the winding roller.

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