선택적 초음파 임프린팅을 사용한 복합 미세패턴의 복제기술

이현중(Hyun Joong Lee),정우신(Woosin Jung),박근(Keun Park) 대한기계학회 2015 大韓機械學會論文集A Vol.39 No.1

초음파 임프린팅은 초음파 진동에너지를 이용하여 열가소성 고분자 표면에 미세패턴을 복제할 수 있는 공정으로 짧은 성형시간에 적은 에너지로 미세패턴 복제가 가능한 장점이 있다. 최근에는 마스크 필름을 사용한 선택적 임프린팅 기술과 다중 패턴성형이 가능한 반복적 임프린팅 기술이 개발되었다. 본 연구에서는 선택적 초음파 임프린팅에 반복적 임프린팅을 접목시켜 다양한 형태의 다중 복합 미세패턴의 복제기술을 개발하였다. 이를 위해 미세 프리즘 패턴을 포함한 금형과 다양한 형태의 마스크 필름을 사용하여 선택적 연속성형 및 반복성형을 통해 다양한 형태의 미세패턴을 복제할 수 있는 임프린팅 기술을 개발하였다. 또한 복제된 미세패턴 영역에 대해 레이저 조사실험을 실시하여 다양한 형태의 광확산 특성을 갖는 필름을 개발할 수 있음을 확인하였다. Ultrasonic imprinting is a micropattern replication technology for a thermoplastic polymer surface that uses ultrasonic vibration energy; it has the advantages of a short cycle time and low energy consumption. Recently, ultrasonic imprinting has been further developed to extend its functionality: (i) selective ultrasonic imprinting using mask films and (ii) repetitive ultrasonic imprinting for composite pattern development. In this study, selective ultrasonic imprinting was combined with repetitive imprinting in order to replicate versatile micropatterns. For this purpose, a repetitive imprinting technology was further extended to utilize mask films, which enabled versatile micropatterns to be replicated using a single mold with micro-prism patterns. The replicated hybrid micropatterns were optically evaluated through laser light images, which showed that versatile optical diffusion characteristics can be obtained from the hybrid micropatterns.

초음파 임프린팅에서 금형온도에 따른 미세패턴의 전사특성 연구

민경빈(Kyeong Bin Min),박종한(Jong Han Park),박창용(Chang Yong Park),박근(Keun Park) 대한기계학회 2014 大韓機械學會論文集A Vol.38 No.1

초음파 임프린팅은 열가소성 고분자 기판에 미세패턴을 복제할 수 있는 공정으로 타 성형방법에 비해 에너지소모가 적고 성형시간이 단축되는 장점이 있다. 초음파 임프린팅 공정에서는 고분자 기판의 표면에 초음파 진동에너지를 인가하여 소재간의 마찰열과 미세하게 반복되는 변형에너지의 축적을 통해 고분자 표면을 국부적으로 가소화시켜 미세패턴이 전사된다. 본 연구에서는 초음파 임프린팅에서 금형 온도가 미세패턴의 전사성에 미치는 영향을 분석하였다. 이를 위해 금형온도를 변화시켜가며 임프린팅을 수행하여 미세패턴 성형 영역에서의 온도변화를 관찰하였고, 상기 온도변화를 고려하여 미세패턴의 충진과정을 전산모사를 통해 고찰하였다. 또한 금형온도 변화에 따른 패턴의 전사율 및 전사균일도를 측정하여 비교하였다. 상기 결과를 통해 금형온도를 높일수록 초음파 임프린팅시 미세패턴의 전사특성이 향상됨을 확인할 수 있었다. Ultrasonic imprinting is a novel process for replicating micropatterns on thermoplastic polymer substrates with low energy consumption and short cycle time. The polymer substrate is softened by the frictional heat and repetitive deformation energy under ultrasonic excitation; thus, a number of micropatterns are replicated on the softened polymer substrate. In the present work, the effect of mold temperature on the replication characteristics of ultrasonic imprinting is investigated. The temperature change in the patterned region is measured by varying the mold temperature. Numerical simulation is then performed for investigating pattern replication characteristics under various mold temperatures. In addition, pattern replication ratio and uniformity are compared through various experimental measurements. Through the results of these comparisons, it is found that the mold temperature has a significant positive effect on the replication characteristics of ultrasonic imprinting.

선택적 초음파 임프린팅을 사용한 기능성 미세패턴 제작

정우신(Woosin Jung),이현중(Hyun-Joong Lee),박근(Keun Park) 대한기계학회 2014 대한기계학회 춘추학술대회 Vol.2014 No.11

Ultrasonic imprinting is a novel process in which micro/nanoscale patterns can be replicate on thermoplastic polymer films with short imprinting time and low energy consumption. In this study, a selective ultrasonic imprinting process is developed to replicate micropatterns on predefined areas with arbitrary profiles. To replicate micropatterns on selected areas, the conventional imprinting process is modified by placing a profiled metal mask between a target film and a patterned mold. Ultrasonic waves are then selectively transferred to the target film through the mask film, from which micropatterns can be replicated onto the predefined areas. The proposed selective imprinting process is then applied to micropattern replication on arbitrarily profiled areas. In this application, the effects of the mask film and imprinting conditions are discussed in terms of the replication quality in both the masked and the unmasked regions. Through these experimental investigations, it is founded that moderate imprinting conditions are required not only to improve the replication quality in the masked region, but also to prevent excessive replication in the unmasked region.

선택적 초음파 임프린팅을 통한 초소수성 미세패턴의 특성 고찰

이현중(Hyun-Joong Lee),박근(Keun Park) 대한기계학회 2015 대한기계학회 춘추학술대회 Vol.2015 No.11

Ultrasonic imprinting is a method using frictional heat generated by ultrasonic vibration energy, and has a favorable benefit to the micro pattern forming in a short imprinting time and system cost than other processes. In this study, Selective ultrasonic imprinting is performed to form a micro/nano pattern and it attempts to manufacture a superhydrophobic surface having a low surface energy. To compare the characteristic of pattern according to imprinting conditions, selective shape and replication ratio of the pattern by vibration time and mold temperature are investigated. Also, the micro pattern had been theoretically designed to have a hydrophobic property and the super-hydrophobic surface is selectively fabricated by ultrasonic imprinting and silane coating with mask film. So the contact angle and droplet shape are compared with various surface having a different surface energy. Through these experimental investigations, it is founded that selective super-hydrophobic surface is required using selective ultrasonic imprinting with mask film.

초음파 임프린팅을 이용한 열가소성 고분자수지 미세패턴 복제기술

박근(Keun Park),이기연(Ki-Yeon Lee),정우신(Woosin Jung),서영수(Young-Soo Seo) 한국소성가공학회 2012 미세가공 심포지엄 Vol.2012 No.11

The present study concerns the micro-pattern replication on thermoplastic polymer using ultrasonic imprinting. The ultrasonic imprinting process uses ultrasonic vibration energy to generate frictional heat between an ultrasonic horn and the polymer film, from which the surface region of the polymer film is softened sufficiently for the replication of micro-patterns. Various applications of the ultrasonic imprinting are introduced in terms of the ways to improve replication characteristics. Firstly, the effects of tool design parameters as well as experimental conditions are discussed. The effect of the vibration transmission direction on the replication ratio is also investigated.

고 정밀 롤 임프린팅을 이용한 유연 전자소자용 투명전극 제작

유종수(Jong-Su Yu),유세민(Semin Yu),곽선우(Sun-Woo Kwak),김정수(Jung Su Kim) Korean Society for Precision Engineering 2014 한국정밀공학회지 Vol.31 No.11

Transparent conductive films (TCF) with excellent electrical properties and high mechanical flexibility have been widely studied because of their potential for application in optoelectronic devices such as light-emitting diodes, paper displays and organic solar cells. In this paper, we report on low-resistance and high-transparent TCF for flexible device applications. To fabricate a high-resolution roll imprinted TCF, the following steps were performed: the design and manufacture of an electroforming stamp mold, the fabrication of high-resolution roll imprinted on flexible film, the manufacture of Ag-nano paste which was filled into patterned film using a doctor blade process. Also, we was demonstrated with the successful application(ITO free organic photovoltaic) of the developed flexible TCF.

냉간가공 임프린팅을 이용한 전자소자 제작에 관한 연구

이청환(Cheonghwan Lee),배철호(Chulho Bae),유기수(Kisoo Yoo),심재술(Jaesool Shim) 대한기계학회 2018 대한기계학회 춘추학술대회 Vol.2018 No.2

UV임프린트 공정에서 임프린팅 가압력 및 가압시간에 따른 레진 잔막 두께형성에 대한 실험연구

신동혁(Dong Hyuk Shin),장시열(Siyoul Jang) 한국트라이볼로지학회 2010 한국윤활학회지(윤활학회지) Vol.26 No.5

This study is focused on the resin layer formation of UV imprinting process by changing imprinting pressure and period. The mold shape is made for the process of window open over the pattern transfer area and the imprinting period is assigned as the time just before the UV light curing. The residual layer is measured by changing the imprinting period and pressure magnitude, and the measured data of residual layer provides useful information for the design of the process conditions of imprinting processes.

CAE를 이용한 나노 임프린팅 공정 장비의 구조 및 기구동역학 해석

강민석(Min Seok Kang),양희종(Hee Jong Yang),임홍재(Hong Jea Yim),장시열(Siyoul Jang),정재일(Jea Il Jeong),신동훈(Dong Hoon Shin),이기성(Kee Sung Lee) 대한기계학회 2006 대한기계학회 춘추학술대회 Vol.2006 No.11

In this study, an analysis method of an imprinting machine using FEM and flexible multi-body kinematics and dynamics is presented. The virtual simulation of nano-imprinting machine is to evaluate the prototype design in early design step. The simulation for the imprinting machine is not only to analyze static and dynamic characteristics of the machine with a template and a substrate but also to determine design parameters of the components for the imprinting machine, such as dimensions, actuator and sensor specifications. Simulations of the LCD panel and imprinting mechanism in the tilting condition between the template and the substrate using commercial FEM and multi-body dynamics programs are performed to investigate the critical design parameters for optimal design of the imprinting fabrication.

Fabrication of Aligned Nano Patterns on HfZnO based on the Imprinting Method for Liquid Crystal Display

Byeong-Yun Oh 한국기계기술학회 2019 한국기계기술학회지 Vol.21 No.3

We demonstrate convenient alignment technologies using imprinting lithography with sol-gel process. The aligned nano pattern is fabricated on a silicon wafer by laser interference lithography. For conformal imprinting process, aligned nano pattern was transferred onto the polydimethylsiloxane (PDMS). Using a PDMS sheet with aligned nano pattern, aligned nano pattern was created onto the sol-gel driven hafnium zinc oxide by imprinting lithography. The process was conducted at annealing temperatures of 150 °C. The obtained pattern on the HfZnO film acted as a guide for aligning liquid crystal (LC) molecules. The geometric restriction induced by aligned pattern leads to LC alignment along to the aligned nano pattern. The combination of imprint lithography and solution-processed inorganic materials proved good alternative of LC alignment technique.