Hot plate for nanoimprint process and nanoimprint method

Abstract

The application discloses a hot table for a nano-imprinting process and a nano-imprinting method. The hot table is suitable for being connected with an output end of a conveying device and an imprinter to solidify a substrate with an imprinting frame output from the imprinter. The hot table comprises a base plate, a first heat plate arranged on one side of the base plate and used for heat conduction to heat and solidify the substrate, wherein the first heat plate is arranged in a square shape matching the shape of the substrate, a limiting assembly arranged on the periphery of the first heat plate and used for supporting and positioning the imprinting frame at a preset solidification position when the substrate is transferred from the conveying device to the first heat plate, and a heating plate cooperatively arranged with the first heat plate to provide a heat source. The hot table can optimize the temperature distribution uniformity of the substrate during heating and solidification, thereby improving the solidification uniformity of the imprinting material and the surface shape precision of the product, and can effectively match the shape of the substrate, thereby eliminating the subsequent process step of cutting a mold, and improving the production efficiency.

Description

Technical Field

[0001] This invention belongs to the field of nanoimprint technology, specifically relating to a hot stage and nanoimprint method for nanoimprinting. Background Technology

[0002] Nanoimprint lithography, with its advantages of simple process and low cost, is widely used in the fabrication of nanoscale patterns for semiconductor devices, wafer-level microlens arrays, and other applications. This technology involves transferring the pattern to the imprinting material using an imprinting mold. The imprinting material then undergoes a curing process to complete the product formation, with the hot stage being the core equipment in this process. Currently, most hot stages are circular and located inside the imprinting machine, resulting in poor compatibility with square substrates and long curing times, leading to low curing efficiency.

[0003] Therefore, in order to address the above-mentioned technical problems, it is necessary to provide a hot stage for nanoimprinting and a nanoimprinting method. Summary of the Invention

[0004] The purpose of this invention is to provide a hot stage and a nanoimprinting method for nanoimprinting, which can solve the problems of poor adaptability and low curing efficiency of existing hot stages.

[0005] To achieve the above objectives, a specific embodiment of the present invention provides a hot stage for nanoimprinting. The hot stage is suitable for connection to the output end of an imprinting machine via a conveying device to cure a substrate with an imprinting frame output from the imprinting machine. The hot stage includes: a chassis; a first hot plate disposed on one side of the chassis for conducting heat to heat and cure the substrate, wherein the first hot plate is square and adapted to the shape of the substrate; a limiting component disposed on the periphery of the first hot plate, wherein when the substrate is transferred from the conveying device to the first hot plate, the limiting component can support and position the imprinting frame at a preset curing position; and a heating plate installed in conjunction with the first hot plate to provide a heat source.

[0006] In one or more embodiments of the present invention, the thermal conductivity of the first hot plate is in the range of 200 W / m·K to 250 W / m·K.

[0007] In one or more embodiments of the present invention, the heating stage further includes a second heating plate and a heating support member;

[0008] The heating plate is clamped between the first heating plate and the second heating plate, and the thermal support is disposed between the chassis and the second heating plate.

[0009] In one or more embodiments of the present invention, the thickness of the first hot plate is greater than the thickness of the second hot plate.

[0010] In one or more embodiments of the present invention, the thermal support member includes a rigid first support portion and a heat-insulating second support portion, the first support portion being fixedly connected to the chassis, and the second support portion being connected to the second hot plate.

[0011] In one or more embodiments of the present invention, the second support is made of PEEK material.

[0012] In one or more embodiments of the present invention, the hot stage further includes a plurality of micro-head adapter units mounted on the chassis; when the substrate is transferred from the conveying device to the first hot plate, the micro-head adapter units can abut against the imprinting frame to fine-tune the imprinting frame to the preset curing position; and / or,

[0013] The height of the surface of the first hot plate that supports the substrate is approximately the same as the height of the worktable of the printing press.

[0014] In one or more embodiments of the present invention, the limiting component includes a first limiting member mounted on the chassis, the first limiting member being located on the side in a first direction, the first limiting member including a first abutting portion that can support the bottom of the imprinting frame and a first positioning portion that can position the side wall of the imprinting frame.

[0015] Wherein, the first direction is the direction in which the imprint frame moves from the imprinting machine to the first hot plate; and / or,

[0016] The limiting component includes a second limiting member installed on the chassis. The second limiting member is located at the tail end in the first direction. The second limiting member includes a second abutting part that can support the bottom of the imprinting frame and a second positioning part that can position the end of the imprinting frame.

[0017] Wherein, the first direction is the direction in which the imprinting frame moves from the imprinting machine to the first hot plate.

[0018] A specific embodiment of the present invention also provides a nanoimprinting method, the method comprising:

[0019] The substrate coated with embossing material and the mold are placed into an embossing machine for embossing, and the adhesive layer is pre-cured.

[0020] The pre-cured substrate with the mold is transferred to a hot plate and the adhesive layer is heated and cured based on the hot plate.

[0021] The hot stage is the hot stage used in the aforementioned nanoimprinting process.

[0022] In one or more embodiments of the present invention, the method further includes: the pre-curing time of the adhesive layer on the embossing machine is less than the curing time on the hot platen; and / or,

[0023] After the adhesive layer has cured, the method further includes: placing the substrate with the mold directly onto the hot plate to cure the structural layer.

[0024] Compared with existing technologies, the hot stage for the nanoimprinting process of this invention sets the first hot plate to a square shape adapted to the substrate. This optimizes the uniformity of temperature distribution during substrate curing, thereby improving the curing uniformity of the imprinted material and the surface accuracy of the product. It also effectively adapts to the shape of the substrate, eliminating the need for subsequent die-cutting, thus improving production efficiency. Furthermore, the hot stage is independent of the imprinting machine and can be used in conjunction with conveying equipment to separate the imprinting and curing steps. Compared to the traditional method where both steps are completed within the imprinting machine, this invention shortens the imprinting machine's occupancy time, further improving production efficiency and equipment utilization. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the structure of a hot stage for nanoimprinting in one embodiment of the present invention;

[0027] Figure 2 This is a front view of a hot stage for nanoimprinting in one embodiment of the present invention;

[0028] Figure 3 This is an exploded view of a hot stage for nanoimprinting in one embodiment of the present invention;

[0029] Figure 4 for Figure 3 Enlarged view of point A in the middle;

[0030] Figure 5 This is a schematic diagram of the nanoimprinting process in the comparative design of this invention;

[0031] Figure 6 This is a schematic flowchart of a nanoimprinting method in one embodiment of the present invention.

[0032] Explanation of key figure labels:

[0033] 1. Chassis; 2. First heating plate; 3. Limiting assembly; 31. First limiting component; 311. First abutting part; 312. First positioning part; 32. Second limiting component; 321. Second abutting part; 322. Second positioning part; 4. Second heating plate; 5. Heating plate; 6. Thermal support component; 61. First support part; 62. Second support part; 7. Micrometer head adapter unit; 8. Electronic control system; 9. Imprinting frame. Detailed Implementation

[0034] To enable those skilled in the art to better understand the technical solutions in this disclosure, the technical solutions in the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments in this disclosure, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this disclosure.

[0035] Nanoimprint lithography, with its advantages of simple process and low cost, is widely used in the fabrication of nanoscale patterns for semiconductor devices, wafer-level microlens arrays, and other applications. This technology involves transferring the pattern to an imprinting material using an imprinting mold. The imprinting material then undergoes a curing process to complete the product formation, with a hot plate being the core equipment in this process.

[0036] In existing technologies, the heating stage is integrated into the printing press, and it is mostly configured as a circular heating stage. However, circular heating stages have the following inherent drawbacks:

[0037] On the one hand, the temperature distribution of a circular hot stage is prone to differences between the edges and the center (typically ±5-10℃), leading to uneven curing of the imprinting material and affecting the surface accuracy of the product, especially failing to meet the requirements of high-precision products such as chips and microlenses. On the other hand, circular hot stages have poor compatibility with square substrates and imprinting molds, and positioning deviations are prone to occur in the edge areas, increasing the difficulty of process control. Furthermore, existing circular hot stages are mostly made of FR4 or Kapton materials, with a thermal conductivity of only 0.25-0.35 W / m·K, resulting in low heat transfer efficiency and further exacerbating the problem of uneven curing.

[0038] Additionally, please combine Figure 5In terms of process flow, the traditional hot plate heating process requires first completing the imprinting process using an imprinting machine, then removing the substrate with the mold using a suction cup, manually cutting the mold off the substrate, and finally heating and curing it with a hot plate. This process has several drawbacks: First, the cutting step increases manual operation and time costs, and is prone to scratching the mold or causing mold deformation; second, the imprinting and heating steps are interrupted, creating waiting intervals between equipment and processes; third, the mold needs to occupy the imprinting machine for the entire curing process, with a single batch curing time of up to 120 minutes, leading to production interruptions and extremely low equipment utilization; fourth, manually placing soft molds is prone to positioning deviations, affecting process consistency. However, if the substrate with the imprinting frame 9 is placed directly on the circular hot plate without cutting, the traditional hot plate is insufficient to support the entire size of the imprinting frame 9 due to its weight. If placed directly on the hot plate, the substrate a inside the imprinting frame 9 may bear the weight and wrinkle, severely affecting the yield of the finished product. Therefore, the limitations of traditional hot plate structures necessitate a cutting and separation process before heating and curing.

[0039] To address the aforementioned problems, this invention discloses a hot stage and method for nanoimprinting, which improves adaptability to square substrates and optimizes the uniformity of temperature distribution to enhance the curing effect on the imprinted material. Simultaneously, it eliminates the need for cutting steps and waiting time, effectively improving production efficiency.

[0040] The following detailed description of the hot stage and nanoimprinting method of the present invention, with reference to specific embodiments, is provided below.

[0041] Please refer to Figure 1 In one embodiment of the present invention, the hot stage for the nanoimprinting process is suitable for connection to the output end of the imprinting machine via a conveying device, so as to transfer the substrate with imprinting frame 9 (see imprinting frame 9) output from the imprinting machine. Figure 1 The process is marked a) and then cured. The imprinting frame 9 is used to support and tension the substrate a, which in turn is used to facilitate the replication and transfer of the micro / nano structure.

[0042] Please refer to Figure 1 and Figure 2The heating table includes at least a base 1, a first heating plate 2, a limiting component 3, and a heating plate 5. The first heating plate 2 is located on one side of the base 1 and is used for heat conduction to heat and cure the substrate. The heating plate 5 is installed in conjunction with the first heating plate 2 to provide a heat source; they can be fitted together for effective heat conduction. The first heating plate 2 is square, adapted to the shape of the substrate. During the heating and curing process, heat can be more evenly distributed to all areas of the substrate, effectively avoiding the uneven heat distribution or heat waste caused by the mismatched shape of traditional round heating plates, thus ensuring the surface accuracy of the cured product. Furthermore, by adjusting the shape design of the first heating plate 2, potential damage to the template or substrate during the cutting process can be avoided, and operation time can be reduced, thereby improving production efficiency.

[0043] To further optimize the uniformity of temperature conduction on the first hot plate 2, in one optional embodiment, the thermal conductivity of the first hot plate 2 is set in the range of 200 W / m·K to 250 W / m·K. Compared to the low thermal conductivity materials (such as FR4 or Kapton) used in traditional hot stages, this high thermal conductivity range enables rapid heat response and uniform diffusion, significantly reducing the temperature difference between different areas of the surface of the first hot plate 2 and ensuring the consistency of the imprinted material in each area during the curing process.

[0044] Specifically, the first hot plate 2 can be made of aluminum-6061 material that meets the above-mentioned thermal conductivity requirements. It can quickly and evenly conduct heat, reduce hot spot generation, and control the temperature uniformity within ±2℃. It is understood that in other embodiments, other high thermal conductivity materials that meet this range can also be used to make the first hot plate 2, and this application does not impose any restrictions on this. The hot spots mentioned above refer to localized high-temperature areas formed on the surface of the heating platform due to uneven temperature field distribution. These areas have significantly higher temperatures than the surrounding areas, which is a typical problem of traditional circular heating platforms and a core cause of uneven curing of the imprinted material.

[0045] It should be noted that if the circular heating table in the printing press is directly changed to a square one, three major obstacles will be encountered in terms of engineering and process: structural, compatibility, and cost.

[0046] Firstly, the existing structure and space limitations of imprinting machines make it difficult to directly modify the circular hot stage inside the machine. This is because the vacuum chamber, pressure head stroke, and alignment platform of the imprinting machine are designed for circular wafers or circular hot stages. The internal space of the chamber is compact, and converting it to a square hot stage would cause physical interference with the chamber sidewalls, guide rails, and sensors, making installation or movement impossible. This results in significant modification difficulty and high costs.

[0047] Secondly, even if the motion issues are forcibly addressed, there are still risks related to process compatibility and yield. This is because, even if the circular hot platen inside the imprinter is changed to a square one, the imprinter's alignment system, pressure head, and wafer stage remain circularly designed. Square substrates will experience a significant decrease in alignment accuracy during imprinting, easily leading to pattern misalignment. Furthermore, uneven pressure distribution from the pressure head can result in insufficient imprinting or mold breakage at the square corners. In addition, existing processes and customer production lines have already successfully implemented circular processes. Customer wafers, carriers, and downstream processes (etching, inspection) all adhere to circular standards. Forcibly changing to square would require modifications to all upstream and downstream equipment, resulting in extremely high costs.

[0048] Third, even if the cost is negligible, the verification cycle after forced modification will be relatively long. After modifying the hot stage, temperature uniformity verification, process window testing, and reliability testing need to be redone, with a cycle of at least 6-12 months. In this embodiment, by setting an external hot stage, plug-and-play functionality can be achieved without modifying the existing printing press, flexibly meeting the needs of manufacturers.

[0049] However, separating the built-in heating stage from the printing press presents insurmountable obstacles in terms of engineering, process, and cost, making this solution far less feasible. The reasons are as follows: The built-in heating stage is a core component of the vacuum chamber and the equipment's PLC; removing it would compromise the vacuum seal, structural integrity, and process timing control, causing the equipment to malfunction. Interrupting heating and transferring uncured substrate after printing would disrupt resin cross-linking, damage the soft mold, and lose positioning accuracy, directly leading to a sharp drop in yield. Furthermore, removing the heating stage requires reconstructing the chamber, piping, and control software, with a single unit modification costing millions and a cycle exceeding six months, while also voiding the original manufacturer's warranty, making the risks uncontrollable.

[0050] In this application, the technical solution of external hot stage + square first hot plate 2 can adopt segmented pre-curing without touching the core structure of the imprinting machine, which not only ensures the process yield, but also frees up the imprinting machine; at the same time, the square hot stage completely eliminates the cutting step and has better heat conduction uniformity, which can ensure the uniform curing of the imprinting material, making it a better industrial solution.

[0051] Please refer to Figure 2 and Figure 3 The limiting component 3 is disposed on the periphery of the first hot plate 2. When the substrate is transferred from the conveying device to the first hot plate 2, the limiting component 3 can support and position the imprinting frame 9 at the preset curing position. Through the supporting and positioning function of the limiting component 3, the substrate can be accurately guided and placed on the preset curing position on the first hot plate 2, avoiding the displacement that may occur during manual placement, ensuring the consistency of position for each curing operation, thereby improving the stability and repeatability of the process.

[0052] Compared to traditional designs where the hot stage is integrated into the printing press, requiring both the printing and curing steps to be completed simultaneously within the press, resulting in prolonged equipment downtime, this embodiment separates the hot stage from the printing press. This allows for the coordinated use of conveying equipment, separating the printing and curing steps. Compared to the traditional method where both steps are completed within the printing press, this reduces equipment downtime and further improves production efficiency and equipment utilization.

[0053] Please refer to Figure 3 and Figure 4 The limiting component 3 may include a first limiting member 31 mounted on the chassis 1. The first limiting member 31 is located on the side in the first direction. The first limiting member 31 includes a first abutting portion 311 that supports the bottom of the imprinting frame 9 and a first positioning portion 312 that positions the side wall of the imprinting frame 9. The limiting component 3 may also include a second limiting member 32 mounted on the chassis 1. The second limiting member 32 is located at the tail end in the first direction. The second limiting member 32 includes a second abutting portion 321 that supports the bottom of the imprinting frame 9 and a second positioning portion 322 that positions the end of the imprinting frame 9. The first direction is the direction in which the imprinting frame 9 moves from the imprinting machine to the first hot plate 2. In this embodiment, the first direction can be referred to as... Figure 3 The direction indicated by the X arrow in the diagram. The first abutting portion 311 and the first positioning portion 312 can cooperate to form an "L"-shaped structure for supporting and positioning the imprinting frame 9. Similarly, the second abutting portion 321 and the second positioning portion 322 can also cooperate to form the above-described structural form; this application does not impose any limitations on this.

[0054] Therefore, when the substrate is conveyed above the hot plate, the first abutment portion 311 first provides upward support to the edge of the imprinting frame 9 to prevent it from falling; simultaneously, the first positioning portion 312 guides and constrains it in the horizontal direction by contacting the side wall of the imprinting frame 9, ensuring its accurate lateral position in the direction of movement. Similarly, when the substrate moves to the predetermined endpoint along the first direction, the second limiting member 32 can further support the imprinting frame 9 through the second abutment portion 321, and the second positioning portion 322 can position the substrate in the longitudinal direction of movement by abutting the end of the imprinting frame 9. Therefore, through lateral guidance and end stop, the first limiting member 31 and the second limiting member 32 work together to achieve rapid, accurate, and reliable positioning of the substrate in the plane without the need for a complex sensing system, thereby ensuring the subsequent curing effect of the substrate.

[0055] Please refer to Figure 3 and Figure 4The heating platform may also include a second heating plate 4 and a heat support 6. The heating plate 5 is sandwiched between the first heating plate 2 and the second heating plate 4, and the heat support 6 is disposed between the chassis 1 and the second heating plate 4. In this embodiment, the heating plate 5 can be a mica sheet. Since the mica heating plate has an embedded metal electric heating mesh, this mesh structure lacks structural load-bearing capacity in the vertical direction. If it directly contacts the heated object (such as a substrate) and bears mechanical loads, it is highly likely to cause deformation of the internal mesh, damage to interlayer insulation, or local breakdown, leading to electrical short circuits, leakage, or thermal runaway. Therefore, in this application, by sandwiching the heating plate 5 between the first heating plate 2 and the second heating plate 4, a double-sided composite heat-conducting layer structure can be formed. The upper and lower heat-conducting interfaces respectively achieve directional heat transfer to the heated object and the environment away from it. While ensuring heat conduction efficiency, the mesh is encapsulated within an insulating-heat-conducting composite system, fundamentally avoiding the direct action of mechanical stress on the heating plate 5, thereby providing a certain degree of protection for the heating plate 5 and improving its durability. The second hot plate 4 and the heating plate 5 can also be set to be square to match the shape of the first hot plate 2, so as to ensure the uniformity of the surface temperature of the first hot plate 2 and further ensure the curing effect.

[0056] Please refer to Figure 3 The thickness of the first hot plate 2 is greater than that of the second hot plate 4. Considering the relatively high actual temperature of 200°C on the heating platform, the thicker first hot plate 2 slows down the heat flow rate, thus preventing uncontrollable temperature issues caused by rapid heating. The second hot plate 4 is thinner, has lower thermal resistance, and responds more quickly to changes in the heat source. Therefore, it can be used in conjunction with temperature detection points to obtain more sensitive and representative temperature feedback, thereby enabling timely response and adjustment of the temperature of the heating plate 5, indirectly controlling the temperature of the first hot plate 2 and ensuring that its temperature is controlled within a preset range.

[0057] Please refer to Figure 3 and Figure 4 The thermal support component 6 includes a rigid first support portion 61 and a heat-insulating second support portion 62. The first support portion 61 is fixedly connected to the chassis 1, and the second support portion 62 is connected to the second hot plate 4. Understandably, the fixed connection of the first support portion 61 to the chassis 1 provides a solid structural foundation for the installation of the first hot plate 2, the heating plate 5, and the second hot plate 4, ensuring the positional accuracy and stability of the heating platform during long-term use. The second support portion 62, connected to the second hot plate 4, effectively blocks the heat conduction path from the second hot plate 4 to the chassis 1, reducing heat loss and thus ensuring the structural stability and flatness of the entire heating platform under high-temperature operating conditions.

[0058] Specifically, the second support 62 can be made of PEEK material. PEEK material has excellent high temperature resistance and mechanical stability, which can effectively reduce energy loss during heat conduction. At the same time, it can suppress thermal deformation, reduce energy loss, and ultimately accurately control the temperature uniformity within ±2℃. It can completely eliminate the obvious temperature difference between the edge and the center, ensure uniform curing of the imprinted material, and will not affect the surface accuracy of the product, thus reducing the impact of thermal errors.

[0059] In this embodiment, the thermal support 6 serves as a supporting structure, balancing rigidity and thermal conductivity control. Within a limited space, it ensures high consistency while suppressing downward heat transfer. Considering the system's maximum design temperature of approximately 200°C, a multi-material composite splicing method (combining high rigidity and low thermal conductivity materials) effectively reduces the thermal impact on the lower electrical control unit while ensuring structural stability and assembly accuracy, thus improving system safety.

[0060] Please refer to Figure 2 and Figure 3 The heating table also includes multiple micrometer head adapter units 7 mounted on the chassis 1. When the substrate is transferred from the conveying device to the first hot plate 2, the micrometer head adapter units 7 can abut against the imprinting frame 9 to fine-tune the imprinting frame 9 to a preset curing position. When the substrate is transferred from the conveying device to the first hot plate 2, these micrometer head adapter units 7 can abut against the imprinting frame 9. Through the precision adjustment function of the micrometer head, the position of the imprinting frame 9 can be finely adjusted at the micrometer level, thereby precisely guiding it to the preset curing position. In this embodiment, four micrometer head adapter units 7 can be provided, respectively located at the four corners of the imprinting frame 9, thereby enabling precise adjustment of the position of the imprinting frame 9. The aforementioned micrometer head adapter units 7 can be structures such as micrometers, which can cooperate to achieve precise position adjustment. In other embodiments, the number of micrometer head adapter units 7 can also be adjusted according to actual conditions; this application does not impose specific limitations on this.

[0061] Please refer to Figure 2 The height of the surface of the first hot plate 2 that supports the substrate is approximately the same as the height of the worktable of the printing press. By achieving the same height between the working surface of the hot plate and the working surface of the printing press, the conveying equipment can achieve horizontal transfer of the substrate between the printing press and the hot plate without complex vertical lifting movements. This simplifies the design of the conveying mechanism and avoids vibration or impact caused by height differences, ensuring the structural integrity of the printing frame 9 during the transfer process.

[0062] Please refer to Figure 1The heating platform may also include an electronic control system 8, which may include a temperature control system and sensing devices. The temperature control system can provide heating power to the heat source through four power lines. The sensing devices can be used to monitor the set parameters and actual operating parameters of the temperature control system in real time, and achieve adaptive temperature adjustment based on the set values.

[0063] Please refer to Figure 1 and Figure 6 One embodiment of this application also provides a nanoimprinting method, comprising: placing a substrate coated with an imprinting material and a mold into an imprinting machine for imprinting, and pre-curing an adhesive layer; transferring the pre-cured substrate with the mold onto a hot plate, and heating and curing the adhesive layer on the hot plate; wherein the hot plate is the hot plate used in the nanoimprinting process in any of the foregoing embodiments. In this embodiment, the adhesive layer can be pre-cured at a parameter of 60°C × 30 min, and the curing on the hot plate can be performed at a parameter of 60°C × 90 min. The above is only an exemplary example and is not intended to limit the adjustment of its parameters.

[0064] Therefore, by dividing the curing process into two stages—pre-curing within the embossing machine and final curing on the hot platen—the embossing and curing processes are separated. This effectively shortens the single-batch occupancy time of the embossing machine, allowing it to quickly move to the next embossing cycle, while the curing process is carried out in parallel on a dedicated hot platen, thereby greatly improving the efficiency of the entire production process and equipment utilization.

[0065] Specifically, the above method also includes setting the pre-curing time of the adhesive layer in the embossing machine to be shorter than the curing time on the hot platen. This time allocation strategy further reduces the prolonged occupation of the embossing machine by the curing step, allowing the subsequent curing process to be completed by a dedicated hot platen with excellent thermal uniformity, thereby maximizing the embossing machine's capacity while ensuring curing quality.

[0066] After the adhesive layer has cured, the method further includes placing the substrate with the mold directly onto the hot plate for curing the structural layer. Therefore, this hot plate is suitable for various curing scenarios. In one embodiment, the curing of the structural layer can be performed at 80°C for 30 minutes. Again, this is merely an exemplary example and not a limitation on parameter adjustments.

[0067] It should be noted that in the nanoimprinting process, the adhesive layer is mainly responsible for enhancing the adhesion between subsequent layers and the substrate, preventing pattern peeling; the structural layer is the main material coated on the adhesive layer, which directly forms the desired nano-pattern through the imprinting template. The curing of both is usually carried out in steps: first, the adhesive layer is cured to stabilize the interface, and then the structural layer is cured after imprinting to permanently fix the pattern, thereby ensuring the complete transfer and reliable replication of high-precision patterns.

[0068] Based on the aforementioned hot stage and corresponding nanoimprinting method, this application conducted comparative tests using two templates, A and B, and the results show:

[0069] First, the surface accuracy of products cured using the square hot platen of this invention is consistent with the trend of traditional process products, and the error fluctuation range is smaller, resulting in better consistency. Second, the number of batches that the embossing machine can process per day has increased from 12 batches in the traditional process to 48 batches, and the equipment utilization rate has increased by 300%. Third, the soft mold damage rate has decreased from 8% in the traditional process to less than 1%, and the process stability has been significantly improved.

[0070] Furthermore, in order to verify the temperature distribution uniformity of the square heating stage of the present invention, a comparative test on its temperature uniformity was conducted.

[0071] The comparative tests used a traditional circular hot stage (material FR4, thermal conductivity 0.3 W / m·K) and a square hot stage (material aluminum-6061, thermal conductivity 220 W / m·K, first hot plate size adapted to the substrate) under the same environmental conditions to test the temperature field.

[0072] The test method is as follows: Heat the hot stage to the set temperature of 60℃, stabilize for 30 minutes, and then use a high-precision thermocouple array (9 points evenly distributed) to measure the temperature of each point on the upper surface of the hot stage. Record the maximum and minimum values, and calculate the temperature difference and standard deviation.

[0073] The test results are shown in the table below:

[0074]

[0075] The above data shows that the surface temperature difference of a traditional circular heating stage can reach ±5-10℃ or more, and the temperature standard deviation exceeds ±3℃, which can easily lead to uneven curing of the imprinted material. In contrast, the maximum temperature difference of the heating stage of this invention can be controlled within ±2.3℃, and the temperature standard deviation is less than ±0.7℃, improving temperature uniformity by about 80%. This superior performance is attributed to the high degree of fit between the square heating plate and the substrate shape, the rapid heat diffusion capability of the high thermal conductivity material (aluminum-6061), and the suppression of heat loss by the composite thermal insulation support structure (thermal support 6), thereby ensuring that the imprinted material is heated evenly during the curing process and significantly improving the surface accuracy of the product.

[0076] In summary, the hot stage and nanoimprinting method of the present invention have at least the following beneficial effects:

[0077] (1) Significantly improved precision: The square first hot plate 2 is perfectly matched with the square substrate and mold. Combined with the material design of the first hot plate 2, the uniformity of its surface can be ensured, effectively reducing hot spots and thermal deformation, and significantly improving the surface precision of the product. In particular, the material selection of the heat support can further suppress thermal errors and reduce the impact of thermal deformation on precision.

[0078] (2) Significantly improved efficiency: For the adhesive layer, the embossing machine only needs to complete 30 minutes of pre-curing, and the subsequent curing work is completed independently by the hot table. The embossing machine occupancy time is reduced from 120 minutes to 30 minutes, and the equipment utilization rate is increased by 75%. At the same time, it eliminates the cutting and manual transfer steps, and the single batch process time is shortened by 20-30 minutes, significantly improving production efficiency.

[0079] (3) Simplified and stable process: No need for cutting molds, avoiding mold damage and positioning deviation caused by manual operation; modular structure and guide rail design ensure smooth transfer of substrate and accurate positioning, greatly improving process consistency.

[0080] (4) High compatibility and low cost: It can be seamlessly integrated with existing printing machines, compatible with a variety of templates, without the need to modify the production line or adjust the core process parameters, and the implementation cost is low.

[0081] (5) Outstanding thermal performance advantages: Compared with traditional circular hot stages FR4 and Kapton materials, the high thermal conductivity of aluminum-6061 makes heat conduction more efficient. Combined with the temperature field optimization of the square structure, it can effectively optimize the uniformity of curing.

[0082] In the description of the embodiments of the present invention, it should be understood that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are only used to facilitate the description of the present invention and to simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0083] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances.

[0084] In the description of the embodiments of the present invention, it should also be noted that the terms "first," "second," etc., used herein do not specifically refer to any order or sequence, nor are they intended to limit the present case; they are merely used to distinguish components or operations described using the same technical terms.

[0085] It will be apparent to those skilled in the art that this disclosure is not limited to the details of the exemplary embodiments described above, and that this disclosure can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of this disclosure is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this disclosure. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0086] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A hot stage for nanoimprint lithography, characterized in that, The hot stage is suitable for connection to the output end of the imprinting machine via a conveying device to cure the substrate with the imprinting frame (9) output from the imprinting machine. The hot stage includes: Chassis (1); The first hot plate (2) is disposed on one side of the chassis (1) for conducting heat to heat and cure the substrate, and the first hot plate (2) is configured as a square shape that is adapted to the shape of the substrate; The limiting component (3) is disposed on the periphery of the first hot plate (2). When the substrate is transferred from the conveying device to the first hot plate (2), the limiting component (3) can support and position the imprinting frame (9) at a preset curing position. A heating plate (5) is installed in conjunction with the first heating plate (2) to provide a heat source.

2. The hot stage for nanoimprinting according to claim 1, characterized in that, The thermal conductivity of the first hot plate (2) ranges from 200W / m·K to 250W / m·K.

3. The hot stage for nanoimprinting according to claim 1, characterized in that, The heating platform also includes a second heating plate (4) and a heating support (6); The heating plate (5) is sandwiched between the first heating plate (2) and the second heating plate (4), and the thermal support (6) is disposed between the chassis (1) and the second heating plate (4).

4. The hot stage for nanoimprinting according to claim 3, characterized in that, The thickness of the first hot plate (2) is greater than the thickness of the second hot plate (4).

5. The hot stage for nanoimprinting according to claim 3, characterized in that, The thermal support member (6) includes a rigid first support part (61) and a heat-insulating second support part (62). The first support part (61) is fixedly connected to the chassis (1), and the second support part (62) is connected to the second hot plate (4).

6. The hot stage for nanoimprinting according to claim 5, characterized in that, The second support (62) is made of PEEK material.

7. The hot stage for nanoimprinting according to claim 1 or 3, characterized in that, The hot table also includes multiple micro-head adapter units (7) mounted on the chassis (1); when the substrate is transferred from the conveying device to the first hot plate (2), the micro-head adapter unit (7) can abut against the imprinting frame (9) to fine-tune the imprinting frame (9) to the preset curing position; and / or, The height of the surface of the first hot plate (2) used to support the substrate is approximately the same as the height of the worktable of the printing press.

8. The hot stage for nanoimprinting according to claim 1, characterized in that, The limiting component (3) includes a first limiting member (31) installed on the chassis (1). The first limiting member (31) is located on the side in a first direction. The first limiting member (31) includes a first abutting part (311) that can support the bottom of the imprinting frame (9) and a first positioning part (312) that can position the side wall of the imprinting frame (9). Wherein, the first direction is the direction in which the imprint frame (9) moves from the imprinting machine to the first hot plate (2); and / or, The limiting component (3) includes a second limiting member (32) installed on the chassis (1). The second limiting member (32) is located at the tail end in the first direction. The second limiting member (32) includes a second abutting part (321) that can support the bottom of the imprinting frame (9) and a second positioning part (322) that can position the end of the imprinting frame (9). Wherein, the first direction is the direction in which the imprint frame (9) moves from the imprinting machine to the first hot plate (2).

9. A nanoimprinting method, characterized in that, The method includes: The substrate coated with embossing material and the mold are placed into an embossing machine for embossing, and the adhesive layer is pre-cured. The pre-cured substrate with the mold is transferred to a hot plate and the adhesive layer is heated and cured based on the hot plate. The hot stage is the hot stage for nanoimprinting process as described in any one of claims 1-8.

10. The nanoimprinting method according to claim 9, characterized in that, The method further includes: the pre-curing time of the adhesive layer on the embossing machine is less than the curing time on the hot platen; and / or, After the adhesive layer has cured, the method further includes: placing the substrate with the mold directly onto the hot plate to cure the structural layer.

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