열 나노임프린트 리소그래피에서의 몰드와 열가소성 폴리머 필름 사이의 응착 특성

김광섭(Kwang-Seop Kim),강지훈(Ji-Hoon Kang),김경웅(Kyung-Woong Kim) 한국트라이볼로지학회 2008 한국윤활학회지(윤활학회지) Vol.24 No.5

Adhesion tests were conducted to investigate the adhesion characteristics between mold and thermoplastic polymer film. Coating of anti-sticking layer (ASL), a kind of polymer material, imprint pressure, and separation velocity were considered as the process conditions. A piece of fused silica without patterns on its surface was used as a mold and the thermoplastic polymer films were made on Si substrate by spin-coating the commercial polymer solution such as mr-I PMMA and mr-I 7020. The ASL was derived from (1H, 1H, 2H, 2H -perfluorooctyl) trichlorosilane(F₁₃-OTS) and coated on the fused silica mold in vapor phase. The pull-off force was measured in various process conditions and the surfaces of the mold and the polymer film were observed after separation. It was found that the adhesion characteristics between the mold and the thermoplastic polymer film and the release performance of ASL were changed according to the process conditions. The ASL was effective to reduce the pull-off force and the damage of polymer film. In cases of the mold coated with ASL, the pulloff force did not depend on imprint pressure and separation velocity.

열가소성 폴리머 필름의 마이크로 점착 거동에 대한 온도의 영향

김광섭(Kwang-Seop Kim),허정철(Jung-Chul Heo),김경웅(Kyung-Woong Kim) 한국트라이볼로지학회 2009 한국윤활학회지(윤활학회지) Vol.25 No.2

Adhesion tests were carried out in order to investigate the effect of temperature on the adhesion behavior between a PMMA film and a fused silica lens in the micro scale. For the tests, a microtribometer system was specially designed and constructed. The pull-off forces on the PMMA film were measured under atmospheric condition as the temperature of the PMMA film was increased from 300 K to 443 K and decreased to 300 K. The contact area between the PMMA film and the lens was observed during the test. The adhesion behavior was changed with the change of the PMMA surface state as the temperature increased. In glassy state below 363 K, the pull-off force did not change with the increase of temperature. In rubbery state from 383 K to 413 K, the pull-off force increased greatly as the temperature increased. In addition, the area of contact was enlarged. In viscous state above 423 K, the fingering instability was observed in the area of contact when the PMMA film contacted with the lens. It was also found that the adhesion behavior can be varied with the thermal history of the PMMA film. The residual solvent in the PMMA film could emerge to the PMMA surface due to the heating and reduced the pull-off force.

열가소성 폴리머 필름의 마이크로 점착 거동에 대한 온도의 영향

김광섭(Kwang-Seop Kim),허정철(Jung-Chul Heo),김경웅(Kyung-Woong Kim) 한국트라이볼로지학회 2008 한국트라이볼로지학회 학술대회 Vol.2008 No.11

Adhesion tests were carried out in order to investigate the effect of temperature on the adhesion behavior between a PMMA film and a fused silica lens in the micro scale. For the tests, a microtribometer system was specially designed and constructed. The pull-off forces on the PMMA film were measured under atmospheric condition as the temperature of the PMMA film was increased from 300 K to 443 K and decreased to 300 K. The contact area between the PMMA film and the lens was observed. The adhesion behavior was changed with the change of the PMMA surface state as the temperature increased. In glassy state below 363 K, the pull-off force did not changed with the increase of the temperature. In rubbery state from 383 K to 413 K, the pull-off force increased greatly as the temperature increased. In addition, the area of contact was enlarged. In viscous state above 423 K, the fingering instability was observed in the area of contact when the PMMA film contacted with the lens. It was also found that the adhesion behavior can be varied with the thermal history of the PMMA film. The residual solvent in the PMMA film could emerge to the PMMA surface due to the heating and reduced the pull-off force.

열가소성 폴리머 필름의 마이크로 점착 및 마찰 거동에 대한 온도의 영향

김광섭(Kwang-Seop Kim),허정철(Jung-Chul Heo),김경웅(Kyung-Woong Kim) 한국트라이볼로지학회 2008 한국트라이볼로지학회 학술대회 Vol.2008 No.6

Adhesion and friction tests were carried out in order to investigate the adhesion and friction behaviors between a PMMA film and a fused silica lens and the effect of temperature on the behaviors in the micro scale. For the tests, a microtribometer system was used. The pull-off and friction forces on the PMMA film were measured under atmospheric condition as the temperature of the PMMA film was increased from 300 K to 443 K (heating) and decreased to 300 K (cooling). The adhesion and friction behaviors were changed with the change of the PMMA surface state as the temperature increased. In glassy state below 363 K, the PMMA film was partially tom out due to adhesive friction during sliding and the transfer layer of the PMMA film was formed in the interface. In rubbery state from 363 K to 423 K, the pull-off and friction forces increased greatly as the temperature increased. In addition, the deformation of the PMMA surface was observed due to ploughing friction. In viscous state above 423 K. the fingering instability was observed when the PMMA film contacted with the lens. It was also found that the adhesion and friction behaviors can be varied with the thermal history of the PMMA film. The residual solvent in the PMMA film could emerge to the PMMA surface due to the heating and reduced the pull-off and friction forces.

열가소성 폴리머 필름의 트라이볼로지 특성에 대한 온도의 영향

김광섭(Kwang-Seop Kim),허정철(Jung-Chul Heo),김경웅(Kyung-Woong Kim) 한국트라이볼로지학회 2009 한국트라이볼로지학회지 (Tribol. Lubr.) Vol.25 No.4

Friction tests were carried out in order to investigate the effects of temperature on the friction and wear behaviors between a PMMA film and a fused silica lens using a microtribometer. The friction forces on the PMMA film were measured under atmospheric condition as the temperature of the film was increased from 300 K to 443 K. The contact area between the film and the lens was observed. The tribological characteristics of the film were significantly changed as the temperature increased. The changes were discussed with the change of the film state from glassy to viscous flow. In addition, the results showed that the friction behavior can be varied with the thermal history of the PMMA film. Residual solvent in the PMMA film could emerge to the PMMA surface due to an additional heating and the solvent on the film surface decreased the friction force.

지르코니아 나노입자 기반 나노패턴 금속 몰드 제작과 열가소성 재료의 복제성형 응용

박세림,민경찬,장소원,하유진,김욱배 한국정밀공학회 2022 한국정밀공학회지 Vol.39 No.7

Fabrication of a durable and strong nanopatterned mold insert using metal sheet and plate is important for molding of thermoplastic materials. Conventionally, the nickel stamper replicating a master pattern by electroforming process hasbeen used for injection molding of nanotextured products such as Blu-ray media. However, a more facile and cheaper mold fabrication process is highly required for manufacturing of functional products based on nanostructured surface. In this study, zirconia nanoparticles were blended with UV curing polymer to fabricate a polymer nanocompositebased nanopattern mold. Compared to the cured pure Ormostamp, the modulus of elasticity of the nanocomposite filled with approximately 54 vol% of zirconia nanoparticles increased by 160 times. Additionally, the modulus of elasticity reached 197 GPa by thermal decomposition of the UV-Cured polymer and post-annealing at 800°C of the nanoparticle layer. The nanopatterns were formed on stainless steel sheet and block, and applied to hot embossing of the PMMA films and injection molding of the COC materials, respectively. No deterioration of the mold occurred during the hot embossing 30 times and the injection molding 600 shots. Nanoparticle-enhanced UV curing nanocomposites or post-heat treatment methods are cost-efficient and easy, because many molds can be manufactured from one master pattern.