Transactions of the Korean Society of Mechanical Engineers A (대한기계학회논문집A)

The Korean Society of Mechanical Engineers (대한기계학회)
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Replication Characteristics of Micropatterns According to Mold Temperature in Ultrasonic Imprinting

초음파 임프린팅에서 금형온도에 따른 미세패턴의 전사특성 연구

  • Min, Kyeong Bin (Dept. of Mechanical and System Design Engineering, Seoul Nat'l Univ. of Science and Technology) ;
  • Park, Jong Han (Dept. of Mechanical and System Design Engineering, Seoul Nat'l Univ. of Science and Technology) ;
  • Park, Chang Yong (Dept. of Mechanical and System Design Engineering, Seoul Nat'l Univ. of Science and Technology) ;
  • Park, Keun (Dept. of Mechanical and System Design Engineering, Seoul Nat'l Univ. of Science and Technology)
  • 민경빈 (서울과학기술대학교 기계시스템디자인공학과) ;
  • 박종한 (서울과학기술대학교 기계시스템디자인공학과) ;
  • 박창용 (서울과학기술대학교 기계시스템디자인공학과) ;
  • 박근 (서울과학기술대학교 기계시스템디자인공학과)
  • Received : 2013.09.25
  • Accepted : 2013.11.04
  • Published : 2014.01.01
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Abstract

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.

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.

Keywords

References

  1. Lan, H., Ding, Y., Liu, H. and Lu, B., 2007, "Review of the Wafer Stage for Nanoimprint Lithography," Microelec. Eng. Vol. 84, No. 4, pp. 684-688. https://doi.org/10.1016/j.mee.2007.01.002
  2. Becker, J. and Heim, U., 2000, "Hot Embossing as a Method for the Fabrication of Polymer High Aspect Ratio Structures," Sens. Actuators A, Vol. 83, No. 1-3, pp. 130-135. https://doi.org/10.1016/S0924-4247(00)00296-X
  3. Giboz, J., Copponnex, T. and Mele, P., 2007, "Micro- Injection Molding of Thermoplastic Polymers: a Review," J. Micromech. Microeng. Vol. 17, No. 6, R96-109.
  4. Park, K. and Lee, S. I., 2010, "Localized Mold Heating with the Aid of Selective Induction for Injection Molding of High Aspect Ratio Microfeatures," J. Micromech. Microeng. Vol. 20, No. 3, 035002. https://doi.org/10.1088/0960-1317/20/3/035002
  5. Lin, C. H. and Chen, R., 2007, "Effects of mold Geometries and Imprinted Polymer Resist Thickness on Ultrasonic Nanoimprint Lithography," J. Micromech. Microeng., Vol. 17, No. 7, pp. 1220-1231. https://doi.org/10.1088/0960-1317/17/7/002
  6. Yu, H. W., Lee, C. H., Ko, J. S., Shin, B. and Rho, C. H., 2008, "Polymer Replication Using Ultrasonic Vibration," Trans. Korean Soc. Mech. Eng. A, Vol. 32, No. 5, pp. 419-423. https://doi.org/10.3795/KSME-A.2008.32.5.419
  7. Mekaru, H. and Takahashi, M., 2009, "Frequency and Amplitude Dependences of Molding Accuracy in Ultrasonic Nanoimprint Technology,"J. Micromech. Microeng., Vol. 19, No. 12, 125026. https://doi.org/10.1088/0960-1317/19/12/125026
  8. Seo, Y. S. and Park, K., 2012, "Direct Patterning of Micro-Features on a Polymer Substrate Using Ultrasonic Vibration,"Microsyst. Technol., Vol. 18, No. 12, pp. 2053-2061. https://doi.org/10.1007/s00542-012-1524-y
  9. Jung, W., Ra, J. and Park, K., 2012, "Design Optimization of Ultrasonic Horn for Micro-pattern Replication,"Int. J. Precis. Eng. Manuf., Vol. 13, No. 12, pp. 2195-2201. https://doi.org/10.1007/s12541-012-0291-0
  10. Seo, Y. S., Lee, K. Y., Cho, Y. H. and Park, K., 2012, "Replication Characteristics of Micro-Patterns According to the Vibration Transmission Direction in the Ultrasonic Imprinting Process," Proc. J. Kor. Soc. Prec. Eng., Vol. 29, No. 11, pp. 1256-1263.
  11. Scheer, H. C., Bogdanski, N., Wisseen, M. and Mollenbeck, S., 2007, "Imprintability of Polymers for Thermal Nanoimprint,"Microelec. Eng., Vol. 85, No. 5-6, pp. 890-896.
  12. Wang, X., Yan, J., Li, R. and Yang, S., 2006, "FEM Investigation of the Temperature Field of Energy Director During Ultrasonic Welding of PEEK Composites,"J. Thermoplast. Compos. Mater., Vol. 19, pp. 593-607. https://doi.org/10.1177/0892705706067479

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