Working mold rubber, working mold and preparation method of working mold rubber

Abstract

The invention provides a working mold adhesive, which is applied to a nanoimprint technology and comprises the following components: 1-50wt% of a substance with a layered crystal structure; the content of the acrylic ester is 20 to 90 weight percent; the content of the metacrylic acid ester is 5 to 20 weight percent; the content of the photoinitiator is 1%-10% by weight; wherein the sum of the contents of all the components is 100 wt%. The invention further provides a working mold and a preparation method of the working mold rubber.

Description

Technical Field

[0001] The present application relates to the field of nanoimprint technology, and in particular to a working mold, a working mold, and a method for preparing the working mold. Background Art

[0002] Nanoimprint lithography (NIL) is a high-resolution micro-nanofabrication technology based on the principle of mechanical replication. It achieves batch transfer of patterns by pressing a template (working mold) bearing a nano-pattern into a polymer or resin (such as a thermoplastic polymer or UV-curable resin). Its core processes are divided into two categories: hot embossing (heating to soften the polymer before embossing) and UV embossing (ultraviolet light curing liquid resin). This technology can achieve resolutions below 10nm, is low-cost, and highly efficient, and has widespread applications in fields such as photonic crystals, biosensors, and semiconductor devices.

[0003] Among them, defects in the working mold are one of the key bottlenecks affecting NIL yield. However, mechanical wear of the working mold is a common problem: during multiple imprinting processes, stress between the working mold and the polymer or resin can cause edge blunting or collapse of fine structures (such as lines with high aspect ratios). This is especially pronounced when the working mold made of hard silicon comes into contact with the soft polymer. Summary of the Invention

[0004] In order to improve the durability of the working mold and thus improve the yield of the nanoimprint technology, the first aspect of the embodiment of the present application provides a working mold adhesive, which is composed of the following components: The content of materials with layered crystal structure is 1%~50wt%; The content of acrylate is 20%~90wt%; The content of methacrylate is 5% to 20% by weight; and The content of the photoinitiator is 1%~10wt%; The total content of each component is 100 wt%.

[0005] In the embodiments of the present application, by adding a substance having a layered crystal structure to the working mold compound, the unique layered structure of the substance having a layered crystal structure helps reduce the friction coefficient of the working mold surface made from the working mold compound, making it easier to separate the working mold from the material layer during nanoimprinting. Furthermore, the thermal conductivity and compressive strength of the working mold are also improved, which helps maintain uniform heat distribution within the working mold and stabilizes the dimensions of the working mold, thereby improving the durability of the working mold and enhancing the yield rate of the nanoimprinting technology.

[0006] In some embodiments, the photoinitiator is a free radical initiating type.

[0007] In some embodiments, the material having a layered crystal structure may be at least one of boron nitride, aluminum nitride, and tungsten disulfide.

[0008] A second aspect of the embodiments of the present application provides a working mold, including: basal layer; and The embossing layer covers the surface of the base layer and is made by using the working mold described in any one of the above items.

[0009] The above-mentioned working mold is integrated with the above-mentioned working mold glue, and all the beneficial effects of the above-mentioned working mold glue can be achieved.

[0010] A third aspect of the present invention provides a method for preparing a working mold, comprising the following steps: Mixing acrylate and methacrylate and stirring to form a first mixed solution; adding a photoinitiator to the first mixed solution and stirring the mixture to form a second mixed solution; adding a substance having a layered crystal structure to the solvent while stirring to form a third mixed liquid; mixing the second mixed liquid and the third mixed liquid and stirring them to form a fourth mixed liquid; A working mold is obtained from the fourth mixed liquid.

[0011] The method for preparing the working mold is used to prepare the working mold, so that the prepared working mold can achieve all the above-mentioned beneficial effects.

[0012] In some embodiments, the third mixed solution includes a plurality of nanoparticles, each of which has an average particle size of less than 80 nm and a specific surface area greater than 10 m 2 / g.

[0013] In some embodiments, in the step of adding the substance having a layered crystal structure to the solvent while stirring to form the third mixed liquid, the stirring time is 30 minutes and the stirring rate is greater than 2000 rpm.

[0014] In some embodiments, the step of obtaining the working mold from the fourth mixed liquid includes: obtaining the working mold from the fourth mixed liquid by a reduced pressure distillation method.

[0015] In some embodiments, the solvent may be ethanol, isopropanol, or butanone.

[0016] In some embodiments, when performing the step of mixing acrylate and methacrylate and then stirring to form the first mixed solution, avoid exposure to ultraviolet light. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of a working module according to an embodiment of the present application.

[0018] Figure 2 Flowchart of a method for preparing a working mold according to an embodiment of the present application.

[0019] Description of main component symbols Working mold: 100 Base layer: 10 Embossed layers: 20 Nanoparticles: 21 Border: 30 The following specific implementation methods will further illustrate the present application in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0020] The following will be combined with the embodiments of the present application to clearly and completely describe the technical solutions of the present application. Obviously, the embodiments described are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments of the present application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0021] In this document, the terms "first", "second" and other similar words are not intended to imply any order, quantity or importance, but are merely used to distinguish different elements. In this document, the terms "comprise", "include" and other similar words are intended to indicate logical relationships, and should not be considered to indicate spatial structural relationships. For example, "A includes B" is intended to indicate that B logically belongs to A, and does not mean that B is spatially located inside A. In addition, the meanings of the terms "comprise", "include" and other similar words should be considered open, not closed. For example, "A includes B" is intended to indicate that B belongs to A, but B does not necessarily constitute the whole of A, and A may also include other elements such as C, D, and E.

[0022] In this document, the terms "embodiment" and "embodiment of the present application" do not indicate that the relevant description applies only to a specific embodiment, but rather indicate that the description may also apply to one or more other embodiments. Those skilled in the art should understand that in this document, any description of a particular embodiment can be replaced, combined, or otherwise combined with the relevant description of one or more other embodiments. New embodiments generated by such replacement, combination, or other combination are easily conceivable by those skilled in the art and fall within the scope of protection of this application.

[0023] The working mold adhesive of the embodiment of the present application is composed of the following components: a substance having a layered crystal structure has a content of 1% to 50wt%; an acrylate has a content of 20% to 90wt%; a methacrylate has a content of 5% to 20wt%; and a photoinitiator has a content of 1% to 10wt%. The total content of each component is 100wt%.

[0024] In some embodiments, the working mold is a UV-curable resin. Under ultraviolet (UV) light, the working mold can rapidly undergo photopolymerization reaction and transform from a liquid or viscous state into a solid polymer material.

[0025] In some embodiments, the photoinitiator is a free radical initiator that generates active free radicals by absorbing ultraviolet light energy, thereby triggering and accelerating the polymerization reaction of acrylate or methacrylate.

[0026] Acrylates and methacrylates contain carbon-carbon double bonds (C=C). Under UV light, the free radicals produced by the decomposition of the photoinitiator trigger polymerization of these double bonds, forming a cross-linked network that rapidly cures the liquid resin to a solid state. Acrylates are more reactive than methacrylates, which helps accelerate the curing of the working mold. Due to the steric hindrance of the α-methyl group, the polymerization reaction of methacrylates is slower than that of acrylates, which helps minimize deformation during the curing process and improve pattern fidelity.

[0027] The material having a layered crystal structure may be at least one of boron nitride, aluminum nitride, and tungsten disulfide. Boron nitride, aluminum nitride, and tungsten disulfide are all suspended in the working mold in the form of nanoparticles.

[0028] In some embodiments, the boron nitride is hexagonal boron nitride (h-BN), which has a layered structure. Each layer consists of six-membered rings of alternating boron and nitrogen atoms, and the layers are bonded by van der Waals forces. Aluminum nitride has a wurtzite structure at room temperature, but under certain conditions (such as nanosheet form or high-pressure phase), it can exhibit quasi-layered properties, which has certain similarities to the h-BN structure. Tungsten disulfide belongs to the transition metal disulfide (TMDC) and has a layered structure. In each layer, the central tungsten atom is surrounded by six sulfur atoms in the form of a triangular prism, and the layers are bonded by van der Waals forces.

[0029] As can be seen above, boron nitride, aluminum nitride, and tungsten disulfide all have unique layered structures, which give them excellent lubricity. Therefore, adding at least one of these to the working mold compound can help reduce the coefficient of friction on the surface of the working mold created with the working mold compound. This reduces the resistance between the working mold and the material layer being imprinted during demolding during nanoimprinting, making demolding easier.

[0030] Compared with acrylates and methacrylates, boron nitride, aluminum nitride and tungsten disulfide all have higher thermal conductivity, which is beneficial to improving the thermal conductivity efficiency of the working mold generated based on the working mold glue, so that the working mold can quickly and evenly transfer the heat generated by ultraviolet light to the entire working mold under ultraviolet light irradiation, preventing the working mold from causing differences in the expansion coefficient of the material layer due to local temperature unevenness, causing pattern distortion, and thus reducing the yield of nanoimprint technology.

[0031] By adding a material with a layered crystal structure to the working mold compound, the embodiments of the present application help reduce the friction coefficient of the working mold surface produced using the working mold compound, making it easier to separate the working mold from the material layer during nanoimprinting. Furthermore, because boron nitride, aluminum nitride, and tungsten disulfide inherently have high thermal conductivity, the working mold compound's thermal conductivity is enhanced, facilitating uniform heat distribution within the working mold compound and maintaining stable working mold dimensions, thereby improving the yield of nanoimprinting technology.

[0032] See also Figure 1 The present invention also provides a working mold 100, comprising a base layer 10 and an embossing layer 20 covering the base layer 10. The embossing layer 20 is made of a working mold adhesive. A surface of the embossing layer 20, away from the base layer 10, is formed with a plurality of grooves or protrusions, forming a complete embossed pattern.

[0033] When the working mold 100 is used in the nanoimprint process, the surface of the imprinting layer 20 facing away from the base layer 10 contacts the layer to be imprinted. Pressure is applied to the surface of the base layer 10 facing away from the imprinting layer 20, causing the imprinted pattern on the imprinting layer 20 to be transferred to the layer to be imprinted. Once the imprinted pattern has been fully transferred to the layer to be imprinted, the layer is cured by ultraviolet light irradiation. The working mold 100 is then removed from the cured layer to be imprinted, completing the nanoimprint process.

[0034] The imprint layer 20 is uniformly distributed with multiple nanoparticles 21. Each nanoparticle 21 comprises at least one of boron nitride, aluminum nitride, and tungsten disulfide. Boron nitride, aluminum nitride, and tungsten disulfide have a unique layered structure, which gives them excellent lubricity. Therefore, the uniform distribution of nanoparticles 21 in the imprint layer 20 helps reduce the coefficient of friction on the surface of the imprint layer 20 that is away from the base layer 10. This reduces the resistance between the imprint layer 20 and the layer to be imprinted during demolding during the nanoimprinting process, making demolding easier.

[0035] Moreover, the multiple nanoparticles 21 evenly distributed in the imprinting layer 20 are also beneficial to improving the thermal conductivity and compressive strength of the imprinting layer 20, so that the imprinting layer 20 can quickly and evenly transfer the heat generated by the ultraviolet light to the entire working mold when it is irradiated by ultraviolet light, and reduce the deformation of the imprinting layer 20 when it is subjected to pressure, thereby improving the durability of the working mold 100.

[0036] The working mold 100 also includes a metal frame 30. The frame 30 is attached to the edge of the base layer 10. When pressure is applied to the surface of the base layer 10 away from the imprinting layer 20, the frame 30 prevents the base layer 10 from stretching or bending, which could cause deformation of the imprinting layer 20. The working mold 100 generates heat when exposed to ultraviolet light. The frame 30 also dissipates heat generated within the working mold 100 to the outside of the working mold 100.

[0037] See also Figure 2 The present invention provides a method for preparing a working mold, comprising the following steps: S1, mixing acrylate and methacrylate and stirring to form a first mixed solution; S2, adding a photoinitiator to the first mixed solution and stirring to form a second mixed solution; S3, adding the substance having a layered crystal structure to the solvent while stirring to form a third mixed liquid; S4, mixing the second mixed liquid and the third mixed liquid and stirring to form a fourth mixed liquid; S5, obtaining a working mold from the fourth mixed liquid.

[0038] In step S1, acrylate and methacrylate are injected into a container, mixed, and then stirred. Stirring should be performed in a fume hood or under an inert gas atmosphere (e.g., nitrogen) to prevent the acrylate and methacrylate from contacting air and causing self-polymerization. Furthermore, exposure to ultraviolet light should be avoided to prevent the acrylate and methacrylate from curing.

[0039] Before the step of injecting acrylate and methacrylate into the container, the container is cleaned with anhydrous ethanol and purged with nitrogen to remove impurities attached to the surface of the container and prevent the impurities from being introduced into the working mold.

[0040] Among them, polypropylene containers should be avoided.

[0041] The step of injecting acrylate and methacrylate into the container comprises: first injecting methacrylate into the container, and then slowly adding acrylate into the container.

[0042] The viscosity of acrylate is greater than that of methacrylate. Injecting low-viscosity methacrylate into the container first and then injecting high-viscosity acrylate will help speed up the mixing of methacrylate and acrylate.

[0043] After the step of injecting the acrylic acid ester and the methacrylic acid ester into the container, the acrylic acid ester and the methacrylic acid ester are mixed by a magnetic stirrer or mechanical stirring to form a first mixed liquid.

[0044] In step S2, before adding the photoinitiator to the first mixed solution and stirring to form the second mixed solution, the solid photoinitiator is dissolved in a small amount of methacrylate to form a liquid photoinitiator. This helps prevent the solid photoinitiator from being directly added to the first mixed solution, resulting in excessive local concentration and initiating pre-gelation.

[0045] In step S3 , the solvent may be ethanol, isopropyl alcohol or butanone, and the substance having a layered crystal structure is a powdered solid.

[0046] Before the step of adding the substance having a layered crystal structure into the solvent while stirring to form the third mixed liquid, the solvent is heated to reduce the viscosity of the solvent.

[0047] When performing the step of adding the substance having a layered crystal structure to the solvent while stirring to form the third mixed liquid, observe whether there are visible lumps in the solvent. If there are no visible lumps in the solvent, the formed third mixed liquid is a uniform suspension including multiple nanoparticles.

[0048] Among them, the average particle size of each nanoparticle is less than 80nm and the specific surface area is greater than 10m 2 / g. The average particle size and specific surface area of the nanoparticles were determined using nitrogen adsorption-desorption measurements based on the Brunauer-Emmett-Teller (BET) theory. In the working mold, smaller average particle size and larger specific surface area of the nanoparticles increase their surface energy, helping to prevent nanoparticle aggregation and resulting in distorted imprinted patterns. Furthermore, a larger specific surface area promotes more interfacial interactions between the nanoparticles and other resins in the working mold, thereby enhancing the deformation resistance and wear resistance of the structure formed after curing.

[0049] When performing the step of adding the substance having a layered crystal structure into the solvent while stirring to form the third mixed liquid, a dispersing mixer is used for stirring, the stirring time is 30 minutes, and the stirring rate is greater than 2000 rpm.

[0050] In step S5, a working mold is obtained from the fourth mixed liquid by distillation under reduced pressure.

[0051] The reduced pressure distillation method is used to evaporate the solvent from the fourth mixed liquid, so that the final working mold obtained is a mold with plasticity, which is beneficial to the subsequent curing and molding of the working mold and is beneficial to increasing the storage time of the working mold.

[0052] Compared to distillation at room temperature, the boiling point of the solvent is significantly lowered under reduced pressure, which helps reduce energy consumption. The nanoparticles in the fourth mixed solution tend to aggregate due to capillary forces when the solvent evaporates rapidly. However, the low temperature conditions of reduced pressure distillation reduce the forces between the particles, allowing the nanoparticles to remain dispersed.

[0053] The preparation method of the working mold adhesive in the embodiment of the present application reduces the friction coefficient of the working mold surface obtained by curing the working mold adhesive and improves the thermal conductivity and compressive resistance of the working mold by adding multiple nanoparticles composed of a substance having a layered crystal structure to the working mold adhesive. This is beneficial to reducing the wear on the working mold caused by the increased number of uses of the working mold when applied to nanoimprint technology, thereby improving the durability of the working mold.

[0054] Those skilled in the art should recognize that the above embodiments are merely intended to illustrate the present application and are not intended to limit the present application. As long as they are within the spirit of the present application, appropriate changes and modifications to the above embodiments are within the scope of protection claimed in the present application.

Claims

1. A working mold, used in nanoimprint technology, characterized in that: It is composed of the following components: The content of materials with layered crystal structure is 1%~50wt%; The content of acrylate is 20%~90wt%; The content of methacrylate is 5% to 20% by weight; and The content of the photoinitiator is 1%~10wt%; The total content of each component is 100 wt%.

2. The working mold according to claim 1, characterized in that: The photoinitiator is a free radical initiating type.

3. The working mold according to claim 1, characterized in that: The material having a layered crystal structure may be at least one of boron nitride, aluminum nitride, and tungsten disulfide.

4. A working mold, characterized in that: include: basal layer; as well as The embossing layer covers the surface of the base layer and is made of the working mold according to any one of claims 1 to 3.

5. A method for preparing a working mold, characterized in that: The steps include: Mixing acrylate and methacrylate and stirring to form a first mixed solution; adding a photoinitiator to the first mixed solution and stirring the mixture to form a second mixed solution; adding at least one substance having a layered crystal structure to the solvent while stirring to form a third mixed liquid; mixing the second mixed liquid and the third mixed liquid and stirring them to form a fourth mixed liquid; A working mold is obtained from the fourth mixed liquid.

6. The method for preparing a working mold according to claim 5, wherein: The third mixed liquid includes a plurality of nanoparticles, each of which has an average particle size of less than 80 nm and a specific surface area of more than 10 m 2 / g.

7. The method for preparing a working mold according to claim 5, wherein: In the step of adding the substance having a layered crystal structure into the solvent while stirring to form the third mixed liquid, the stirring time is 30 minutes and the stirring rate is greater than 2000 rpm.

8. The method for preparing a working mold according to claim 5, wherein: The step of obtaining the working mold from the fourth mixed liquid includes: obtaining the working mold from the fourth mixed liquid by a reduced pressure distillation method.

9. The method for preparing a working mold according to claim 5, wherein: The solvent can be ethanol, isopropanol, or butanone.

10. The method for preparing a working mold according to claim 5, wherein: When performing the step of mixing acrylate and methacrylate and then stirring to form the first mixed solution, avoid exposure to ultraviolet light.

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