A method for preparing amorphous fluororesin in a dustproof film for photomask

Abstract

The present invention discloses a method for preparing an amorphous fluororesin in a dustproof film for a photomask, and belongs to the technical field of fluororesin film frame coating. The method uses spin coating to prepare a film with a thickness of only 0.5-5 μm from a fluororesin solution, and the light transmittance of the fluororesin film can reach more than 95%. The film is stretched out by the tension of the liquid, and then separated by an airflow device to fit the tension frame and the film. Not only does it not require manual or machine contact with the film, but it is also highly efficient and avoids film breakage or tearing. At the same time, an antistatic layer is plated to avoid the problem of difficulty in forming due to electrostatic adsorption of the film. The prepared amorphous fluororesin film can be used as a dustproof film for a photomask.

Description

Technical Field

[0001] The invention belongs to the technical field of fluororesin film frame coating, and in particular relates to a method for preparing an amorphous fluororesin in a dustproof film for a photomask. Background Art

[0002] At present, the dust-proof film for photomask is mostly prepared by using amorphous fluororesin as the main material.

[0003] At present, most of the films used are Japanese AGC CYTOP films, with a thickness of 0.8-5μm. However, this type of film still has the technical problem of poor mechanical properties, and often the film thickness is too thin, resulting in the inability to form a frame or the film breaking during the forming process. Summary of the invention

[0004] The first object of the present invention is to provide a method for preparing an amorphous fluororesin in a dustproof film for a photomask. The method uses spin coating to prepare a fluororesin solution into a film with a thickness of only 0.5-5μm, and the light transmittance of the fluororesin film can reach more than 95%.

[0005] The second object of the present invention is to provide a method for preparing an amorphous fluororesin in a dustproof film for a photomask, wherein the method utilizes a segmented spin coating method, which is helpful for preparing a thin film with high thickness uniformity and relatively thin thickness.

[0006] The third purpose of the present invention is to provide a method for preparing amorphous fluororesin in a dust-proof film for a photomask. This method uses the tension of the liquid to stretch the film, and then uses an airflow device to separate the film so that the tension frame and the film fit together. Not only does it not require manual or machine contact with the film, but it also has efficient separation and avoids damage or tearing of the film.

[0007] The present invention is achieved through the following technical solutions:

[0008] A method for preparing an amorphous fluororesin in a dustproof film for a photomask comprises the following steps:

[0009] S1, selecting amorphous fluororesin powder, drying it and mixing it with a fluorine solvent until the amorphous fluororesin powder is completely dissolved to obtain a standby resin solution;

[0010] The mass ratio of the amorphous fluororesin powder to the fluorosolvent is 0.5-10:100;

[0011] S2, finely filter the standby resin solution obtained above, place it in a spin coating device and stir it at a uniform speed, then drop it on the heated spin coating plate, and when the resin solution covers 1 / 2 of the area of ​​the spin coating plate, perform the first speed spin coating treatment and the second speed spin coating treatment respectively, and continue baking for 20-25 minutes;

[0012] S3, the spin-coated disk containing the resin solution that has been baked is further placed at 110-180° C. for 30-35 min, and after cooling, ultrasonic demolding is performed to obtain an amorphous fluororesin film;

[0013] S4, fully expanding the obtained amorphous fluororesin film and floating it on a horizontal liquid surface, and removing water droplets on the film surface by using an air flow device;

[0014] Using a support plate to enter from below the liquid surface and adhere to the amorphous fluororesin film on the liquid surface, and then covering the other side of the amorphous fluororesin film with a tension frame coated with a pressure-sensitive adhesive, the tension frame and the amorphous fluororesin film are bonded;

[0015] Then, the supporting plate is separated by an air flow device to obtain a tension frame containing an amorphous fluororesin film, and vacuum drying is performed;

[0016] S5, placing the tensioning frame containing the amorphous fluororesin film after drying on a tensioning table for tensioning treatment, and then using the finished frame coated with UV pressure-sensitive adhesive to press and bond with the tensioning frame containing the amorphous fluororesin film, trimming the edges, using a UV lamp for radiation curing treatment, and then coating an antistatic layer to obtain a finished product.

[0017] The purpose of drying the amorphous fluororesin powder in the above method is to dry the solvent in the resin powder.

[0018] The reaction principle of mixing amorphous fluororesin powder with fluorosolvent in the above method is that the fluoromaterial itself has very good chemical corrosion resistance. By using the principle of like dissolves like, the amorphous fluororesin powder is completely dissolved by using fluorosolvent, and the resin powder is converted from solid to liquid. The prepared solution can be used for spin coating.

[0019] The purpose of heating the spin coating disk in the above method is to dry and volatilize the solvent to obtain an amorphous fluorine film.

[0020] In the above method, the fluororesin solution is dripped onto the spin coating disc to 1 / 2 of the disc area, in order to make the spin-coated film more uniform. If the material is less, the spin coating surface will not be well covered due to the release force, resulting in uneven thickness and size of the film.

[0021] The purpose of using segmented spin coating in the above method is that the first speed is to spread the solution evenly on the spin coating surface, and the second speed is to throw away the excess resin through the release force, so that a thin layer of solution is left on the spin coating surface. After the solvent is dried, an amorphous fluororesin film is obtained.

[0022] The purpose of performing baking twice after spin coating in the above method is to dry out the solvent in the solution in the first drying and to dry out the residual pure water on the film in the second drying.

[0023] In the above method, UV lamp is used for radiation curing to make the glue react completely.

[0024] All the processes of the above method are performed in a dust-free laboratory with constant temperature and humidity, and all operations are performed with rubber gloves and the film cannot be touched directly because the film is extremely thin and easily damaged or scratched.

[0025] Preferably, in step S1, the drying temperature of the amorphous fluororesin powder is 100-105° C. and the drying time is 1-2 hours.

[0026] Preferably, in step S1, when the amorphous fluororesin powder is dried and mixed with the fluorosolvent, the temperature is 90-110°C and the mixing rate is 100-500r / min.

[0027] The above-mentioned amorphous fluororesin powder is a fluorine-based high polymer. Through synthetic modification and other technical means, the amorphous fluororesin film can be made into a highly light-transmitting and highly breathable product, or a highly light-transmitting and airtight product. Because it has very low surface energy and high hydrophobicity, it can play a good role in release and dust prevention.

[0028] Preferably, in step S2, the fine filtration is 4000-18000 mesh.

[0029] The above-mentioned fine filtration is performed to prevent the presence of incompletely dissolved resin in the solution, which may affect the quality of thin film spin coating.

[0030] Preferably, in step S2, the temperature during uniform stirring is 95-115°C.

[0031] Preferably, in step S2, the diameter of the spin coating disk is not less than 50 mm;

[0032] The temperature of the heated spin coating disc is 40-95°C.

[0033] Preferably, in step S2, the first speed spin coating process is: at a speed of 1000-1800 r / min; the spin coating time is 4-8 s;

[0034] The second speed spin coating process is: at a speed of 2800-6500 r / min; the spin coating time is 20-30 s.

[0035] Preferably, in step S3, the support plate is a PTFE support plate;

[0036] The support plate is provided with a plurality of small holes with a diameter less than 0.1 mm.

[0037] Preferably, in step S4, the vacuum drying temperature is 45-50°C.

[0038] Preferably, in step S5, the tensioning pressure is 0.01-0.3N.

[0039] Compared with the prior art, the present invention has at least the following technical effects:

[0040] (I) The present invention provides a method for preparing an amorphous fluororesin in a dustproof film for a photomask. The method uses spin coating to prepare a fluororesin solution into a film with a thickness of only 0.5-5 μm, and the light transmittance of the fluororesin film can reach more than 95%.

[0041] (ii) The purpose of using segmented spin coating in this method is that the first speed is to spread the solution evenly on the spin coating surface, and the second speed is to throw away the excess resin through the release force, so that a thin layer of solution is left on the spin coating surface. After the solvent is dried, an amorphous fluororesin film is obtained.

[0042] (III) This method uses the tension of the liquid to stretch the film, and then uses the airflow device to separate the tension frame and the film. Not only does it not require manual or machine contact with the film, but it also has high separation efficiency and avoids film damage or tearing. At the same time, the antistatic layer is plated to avoid the problem of difficulty in forming due to electrostatic adsorption of the film.

[0043] (iv) The amorphous fluororesin film prepared by this method can be used as a dust cover for a photomask. DETAILED DESCRIPTION

[0044] The embodiments of the present invention will be described in detail below in conjunction with examples. However, those skilled in the art will understand that the following examples are only used to illustrate the present invention and should not be construed as limiting the scope of the present invention. The specific conditions not specified in the examples are carried out according to conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used without indicating the manufacturer are all conventional products that can be purchased commercially.

[0045] A technical solution of a specific implementation of the present invention is:

[0046] A method for preparing an amorphous fluororesin in a dustproof film for a photomask, comprising:

[0047] 1. First, place the amorphous fluororesin powder in an oven at 105°C and dry it for 2 hours;

[0048] 2. Weigh the corresponding weights of amorphous fluororesin powder and fluoro solvent, and prepare a resin solution in a ratio of 0.5-10:100 according to the actual production process requirements.

[0049] The above-mentioned amorphous fluororesin is selected from: Shanghai Fluoro T6, Japan AGC cytop.

[0050] Fluorine solvent selected, American 3M Company: Model: FC-40.

[0051] 3. Pour the prepared solution into a closed batching kettle. According to the actual proportion of the prepared solution, raise the temperature to 90°C and start stirring at a uniform speed of 100r / min-500r / min.

[0052] 4. After the resin powder is completely dissolved, finely filter it through 4000-18000 mesh and pour it into the spin coating tank. The temperature of the tank is 95℃ and stir at a constant speed.

[0053] 5. The diameter of the spin coating disc should be more than 50 mm.

[0054] After wiping the rotating sheet clean, place it on the rotating disk and fix it. When the temperature of the spin coating disk rises to 70°C, start dripping the fluororesin solution. When the resin solution covers 50% of the area of ​​the spin coating disk;

[0055] Start the first speed spin coating, the spin coating time is 4-8s, the speed is controlled between 1000-1800r / min, after the first spin coating time is completed, start the second spin coating, the spin coating speed is controlled between 2800-6500r / min, and the time is 20-30s.

[0056] 6. After the spin coating is completed, continue to bake for 20 minutes. After the baking is completed, take out the spin-coated glass and bake it in a clean oven at 110°C for 30 minutes.

[0057] 7. After baking, take out the rotating disk and place it at room temperature to cool naturally. After the spin-coated disk cools down, place it in a clean ultrasonic liquid tank for ultrasonic stripping.

[0058] 8. After the membrane is ultrasonically separated from the spin coating disc, wait for the membrane to completely expand and float on the horizontal liquid surface. Start a dry and clean slight airflow to blow away the water droplets on the membrane surface. After the liquid surface is calm, slowly start the PTFE support plate under the liquid surface. After the support plate supports the membrane to be level with the liquid surface and the liquid surface is calm, press and bond the tensioning frame with pressure-sensitive adhesive to the PTFE support plate. At this time, the film has been bonded to the tensioning frame, and the separation airflow is started. At this time, a thin separation air layer is formed between the membrane and the support plate, and the tensioning frame is slowly separated from the bottom support plate. There are many small holes with a diameter of less than 0.1 mm in the middle of the support plate.

[0059] 9. Move the tension frame with the bonded film to a clean vacuum oven and slowly dry it at 45-50℃.

[0060] 10. Move the dried tension frame to a clean vacuum environment at room temperature. Press and tension the tension frame with the film and the tension table with a slightly larger finished product size according to the different film thicknesses. The tensioning force is between 0.01N-0.3N according to the different film thicknesses. After the film is fully tensioned, press and bond the finished frame with UV pressure-sensitive adhesive. After the initial bonding is completed, use a circular knife (flying knife) to cut off the excess corner film. (The cut corner film can be recycled and dissolved to form a film again). After cutting, turn on the UV lamp for irradiation curing to make the glue react completely.

[0061] 11. Move the finished film frame covered with fluororesin film into a vacuum evaporation box to coat the entire frame with an antistatic layer.

[0062] 12. After antistatic treatment, the finished product is obtained and packaged and sealed in a clean environment.

[0063] Embodiment 1:

[0064] A method for preparing an amorphous fluororesin in a dustproof film for a photomask, comprising:

[0065] 1. First, place the amorphous fluororesin powder in an oven at 105°C and dry it for 1 hour;

[0066] 2. Weigh 50g of amorphous fluororesin powder and 10000g of fluorosolvent of corresponding weight, and prepare the resin solution according to the ratio of 1:1.

[0067] The above-mentioned amorphous fluororesins are selected from: Shanghai Fluoro T6, Japan AGC cytop.

[0068] 3. Pour the prepared solution into a closed batching kettle. According to the actual proportion of the prepared solution, raise the temperature to between 110°C and start stirring at a uniform speed of 100r / min-500r / min.

[0069] 4. After the resin powder is completely dissolved, filter it through 4000 mesh fine filtration and pour it into the spin coating tank. The temperature of the tank is 95℃ and stir at a constant speed.

[0070] 5. The diameter of the spin coating disc should be more than 50 mm.

[0071] After wiping the rotating sheet clean, place it on the rotating disk and fix it. When the temperature of the spin coating disk rises to 95°C, start dripping the fluororesin solution. When the resin solution covers 50% of the area of ​​the spin coating disk;

[0072] Start the first speed spin coating, the spin coating time is 4-8s, the speed is controlled between 1000-1800r / min, after the first spin coating time is completed, start the second spin coating, the spin coating speed is controlled between 2800-6500r / min, and the time is 20-30s.

[0073] 6. After the spin coating is completed, continue to bake for 25 minutes. After the baking is completed, take out the spin-coated glass and bake it in a clean oven at 110-180℃ for 35 minutes.

[0074] 7. After baking, take out the rotating disk and let it cool naturally at room temperature. After the spin-coated disk cools down, place it in a clean ultrasonic bath for ultrasonic stripping.

[0075] 8. After the membrane is ultrasonically separated from the spin coating disc, wait for the membrane to completely expand and float on the horizontal liquid surface. Start a dry and clean slight airflow to blow away the water droplets on the membrane surface. After the liquid surface is calm, slowly start the PTFE support plate under the liquid surface. After the support plate supports the membrane to be level with the liquid surface and the liquid surface is calm, press and bond the tensioning frame with pressure-sensitive adhesive to the PTFE support plate. At this time, the film has been bonded to the tensioning frame, and the separation airflow is started. At this time, a thin separation air layer is formed between the membrane and the support plate, and the tensioning frame is slowly separated from the bottom support plate. (There are many small holes with a diameter of less than 0.1 mm in the middle of the support plate).

[0076] 9. Move the tension frame with the bonded film to a clean vacuum oven and slowly dry it at 50°C.

[0077] 10. Move the dried tension frame to a clean vacuum environment at room temperature. Press and tension the tension frame with the film and the tension table with a slightly larger finished product size according to the different film thicknesses. The tensioning force is between 0.01N-0.3N according to the different film thicknesses. After the film is fully tensioned, press and bond the finished frame with UV pressure-sensitive adhesive. After the initial bonding is completed, use a circular knife (flying knife) to cut off the excess corner film. (The cut corner film can be recycled and dissolved to form a film again). After cutting, turn on the UV lamp for irradiation curing to make the glue react completely.

[0078] 11. Move the finished film frame covered with fluororesin film into a vacuum evaporation box to coat the entire frame with an antistatic layer.

[0079] 12. After antistatic treatment, the finished product is obtained and packaged and sealed in a clean environment.

[0080] Embodiment 2:

[0081] A method for preparing an amorphous fluororesin in a dustproof film for a photomask, comprising:

[0082] 1. First, place the amorphous fluororesin powder in an oven at 100°C and dry for 2 hours;

[0083] 2. Weigh 500g of amorphous fluororesin powder and 7000g of fluorosolvent of corresponding weight, and prepare the resin solution according to the ratio of 1:1.

[0084] The above-mentioned amorphous fluororesins are selected from: Shanghai Fluoro T6, Japan AGC cytop.

[0085] 3. Pour the prepared solution into a closed batching kettle. According to the actual proportion of the prepared solution, set the temperature to between 90-110°C and start stirring at a uniform speed of 100r / min-500r / min.

[0086] 4. After the resin powder is completely dissolved, filter it through 15000 mesh fine filtration and pour it into the spin coating tank. The temperature of the tank is 115℃ and stir at a constant speed.

[0087] 5. The diameter of the spin coating disc should be more than 50 mm.

[0088] After wiping the rotating sheet clean, place it on the rotating disk and fix it. When the temperature of the spin coating disk rises to 70°C, start dripping the fluororesin solution. When the resin solution covers 50% of the area of ​​the spin coating disk;

[0089] Start the first speed spin coating, the spin coating time is 4 to 8 seconds, the speed is controlled between 1000 and 1800, after the first spin coating time is completed, start the second spin coating, the spin coating speed is controlled between 2800-6500, and the time is 20-30 seconds.

[0090] 6. After the spin coating is completed, continue to bake for 20 minutes. After the baking is completed, take out the spin-coated glass and bake it in a clean oven at 110-180℃ for 30 minutes.

[0091] 7. After baking, take out the rotating disk and place it at room temperature to cool naturally. After the spin-coated disk cools down, place it in a clean ultrasonic liquid tank for ultrasonic stripping.

[0092] 8. After the membrane is ultrasonically separated from the spin coating disc, wait for the membrane to completely expand and float on the horizontal liquid surface. Start a dry and clean slight airflow to blow away the water droplets on the membrane surface. After the liquid surface is calm, slowly start the PTFE support plate under the liquid surface. After the support plate supports the membrane to be level with the liquid surface and the liquid surface is calm, press and bond the tensioning frame with pressure-sensitive adhesive to the PTFE support plate. At this time, the film has been bonded to the tensioning frame, and the separation airflow is started. At this time, a thin separation air layer is formed between the membrane and the support plate, and the tensioning frame is slowly separated from the bottom support plate. (There are many small holes with a diameter of less than 0.1 mm in the middle of the support plate).

[0093] 9. Move the tension frame with the bonded film to a clean vacuum oven and slowly dry it at 45°C.

[0094] 10. Move the dried tension frame to a clean vacuum environment at room temperature. Press and tension the tension frame with the film and the tension table with a slightly larger finished product size according to the different film thicknesses. The tensioning force is between 0.01N-0.3N according to the different film thicknesses. After the film is fully tensioned, press and bond the finished frame with UV pressure-sensitive adhesive. After the initial bonding is completed, use a circular knife (flying knife) to cut off the excess corner film. (The cut corner film can be recycled and dissolved to form a film again). After cutting, turn on the UV lamp for irradiation curing to make the glue react completely.

[0095] 11. Move the finished film frame covered with fluororesin film into a vacuum evaporation box to coat the entire frame with an antistatic layer.

[0096] 12. After antistatic treatment, the finished product is obtained and packaged and sealed in a clean environment.

[0097] Experimental example:

[0098] Five parallel experiments of film-covered frames were conducted using the method of Example 1, and the average value was taken as the thickness of the film to perform optical transmittance tests at different wavelength bands.

[0099] Table 1 Film coating frame thickness experiment

[0100]

[0101] Note: The above nm is the unit: nanometer, which means one thousandth of a micron.

[0102] Table 2 Transmittance test of different wavelength bands after film coating

[0103] Type 193nm 248nm 365nm Sample1 95.857 98.110 99.721 Sample2 96.697 98.597 99.879

[0104] The above-mentioned display of the transmittance of the amorphous fluororesin film by using different light wavelength bands shows that the transmittance of the resin film prepared by the above-mentioned embodiments of the present application can reach more than 95%.

[0105] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing an amorphous fluororesin in a dustproof film for a photomask, characterized in that: The steps include: S1, selecting amorphous fluororesin powder, drying it and mixing it with a fluorine solvent until the amorphous fluororesin powder is completely dissolved to obtain a standby resin solution; The mass ratio of the amorphous fluororesin powder to the fluorosolvent is 0.5-10:100; S2, finely filter the standby resin solution obtained above, place it in a spin coating device and stir it at a uniform speed, then drop it on the heated spin coating plate, and when the resin solution covers 1 / 2 of the area of ​​the spin coating plate, perform the first speed spin coating treatment and the second speed spin coating treatment respectively, and continue baking for 20-25 minutes; S3, the spin-coated disk containing the resin solution that has been baked is further placed at 110-180° C. for 30-35 min, and after cooling, ultrasonic demolding is performed to obtain an amorphous fluororesin film; S4, fully expanding the obtained amorphous fluororesin film and floating it on a horizontal liquid surface, and removing water droplets on the film surface by using an air flow device; Using a support plate to enter from below the liquid surface and adhere to the amorphous fluororesin film on the liquid surface, and then covering the other side of the amorphous fluororesin film with a tension frame coated with a pressure-sensitive adhesive, the tension frame and the amorphous fluororesin film are bonded; Then, the supporting plate is separated by an air flow device to obtain a tension frame containing an amorphous fluororesin film, and vacuum drying is performed; S5, placing the tensioning frame containing the amorphous fluororesin film after drying on a tensioning table for tensioning treatment, and then using the finished frame coated with UV pressure-sensitive adhesive to press and bond with the tensioning frame containing the amorphous fluororesin film, trimming the edges, using a UV lamp for radiation curing treatment, and then coating an antistatic layer to obtain a finished product.

2. The method for preparing an amorphous fluororesin in a dustproof film for a photomask according to claim 1, characterized in that: In the step S1, the drying temperature of the amorphous fluororesin powder is 100-105° C. and the drying time is 1-2 hours.

3. The method for preparing an amorphous fluororesin in a dustproof film for a photomask according to claim 1, characterized in that: In the step S1, when the amorphous fluororesin powder is dried and mixed with the fluoro solvent, the temperature is 90-110° C. and the mixing rate is 100-500 r / min.

4. The method for preparing an amorphous fluororesin in a dustproof film for a photomask according to claim 1, characterized in that: In step S2, the fine filtration is 4000-18000 mesh.

5. The method for preparing an amorphous fluororesin in a dustproof film for a photomask according to claim 1, characterized in that: In step S2, the temperature during uniform stirring is 95-115°C.

6. The method for preparing an amorphous fluororesin in a dustproof film for a photomask according to claim 1, characterized in that: In step S2, the diameter of the spin coating disk is not less than 50 mm; The temperature of the heated spin coating disc is 40-95°C.

7. The method for preparing an amorphous fluororesin in a dustproof film for a photomask according to claim 1, characterized in that: In step S2, the first speed spin coating process is: at a speed of 1000-1800 r / min; the spin coating time is 4-8 s; The second speed spin coating process is: at a speed of 2800-6500 r / min; the spin coating time is 20-30 s.

8. The method for preparing an amorphous fluororesin in a dustproof film for a photomask according to claim 1, characterized in that: In step S3, the support plate is a PTFE support plate; The support plate is provided with a plurality of small holes with a diameter less than 0.1 mm.

9. The method for preparing an amorphous fluororesin in a dustproof film for a photomask according to claim 1, characterized in that: In step S4, the temperature of vacuum drying is 45-50°C.

10. The method for preparing an amorphous fluororesin in a dustproof film for a photomask according to claim 1, characterized in that: In step S5, the tensioning pressure is 0.01-0.3N.

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