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Injection molding of polymer micro- and sub-micron structures with high-aspect ratios

  • A.-C. Liou
  • R.-H. ChenEmail author
Original Article

Abstract

This work studies the injection molding characteristics of polymer micro- and sub-micron structures using demonstration mold inserts with micro- and sub-micron channels with high-aspect ratios. The effects of the injection molding parameters on the achievable aspect ratio of the micro- and sub-micron walls were investigated. Additionally, distinctive mold-filling behaviors and resulting defects were observed for various polymers, such as polymethyl methacrylate (PMMA), polypropylene (PP) and high-density polyethylene (HDPE). Experimental results reveal that the mold temperature determines the success of the injection molding of micro- and sub-micron walls. The satisfactory mold temperature for micro-injection molding significantly exceeds that for traditional injection molding. Moreover, the main injection pressure and the main injection time substantially affect the achievable aspect ratio of the micro- and sub-micron walls. Furthermore, unusual flow behaviors occur and poor molding results are obtained when PP and HDPE are used for micro-injection molding.

Keywords

High-aspect ratio Injection molding  Micro-structures Molding characteristics  Sub-micron structures 

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References

  1. 1.
    Rötting O, Röpke W, Becker H, Gärtner C (2002) Polymer microfabrication technologies. Microsystem Technol 8:32–36CrossRefGoogle Scholar
  2. 2.
    Studer V, Pépin A, Chen Y (2002) Nanoembossing of thermoplastic polymers for microfluidic applications. Appl Phys Lett 80:3614–3616CrossRefGoogle Scholar
  3. 3.
    Becker H, Heim U (2000) Hot embossing as a method for the fabrication of polymer high-aspect ratio structures. Sens Actuators A 83:130–135CrossRefGoogle Scholar
  4. 4.
    Wimberger-Friedl R (1999) Injection molding of sub-μm grating optical elements. In: Proceedings of SPE ANTEC, New York, pp 476–480Google Scholar
  5. 5.
    Ruprecht R, Bacher W, Haußelt JH, Piotter V (1995) Injection molding of LIGA and LIGA-similar microstructures using filled and unfilled thermoplastics. In: Proceedings of SPIE Vol. 2639, NC, USA, pp 146–157Google Scholar
  6. 6.
    Menges G, Michaeli W, Mohren P (2001) Special processes – special molds. In: How to make injection molds, Hanser, Munich, pp 577–587Google Scholar
  7. 7.
    Mönkkönen K, Hietala J, Pääkkönen P, Pääkkönen EJ, Kaikuranta T, Pakkanen TT, Jääskeläinen T (2002) Replication of sub-micron features using amorphous thermoplastics. Polym Eng Sci 42:1600–1608CrossRefGoogle Scholar
  8. 8.
    Yamagiwa Y (2003) Micro-injection molding. J Japan Soc Polym Proc 15:257–259Google Scholar
  9. 9.
    Koyama K (2000) Structure analysis of plastic products (1). Superstructure analysis of plastics. J Japan Soc Polym Proc 12:209–214Google Scholar
  10. 10.
    Ohwada K, Negoro Y, Konaka Y, Oguchi T (1995) Groove depth uniformization in (1 1 0) Si anisotropic etching by ultrasonic wave and application to accelerometer fabrication. In: Proceedings of IEEE MEMS, Amsterdam, Netherlands, pp 100–105Google Scholar
  11. 11.
    Ayón AA, Zhang X, Khanna R (2001) Anisotropic silicon trenches 300–500 μm deep employing time multiplexed deep etching (TMDE). Sens Actuators A 91:387–391Google Scholar
  12. 12.
    Williams KR, Muller RS (1996) Etch rates for micromachining processing. J MEMS 5:256–269Google Scholar
  13. 13.
    Williams KR, Gupta K, Wasilik M (2003) Etch rates for micromachining processing – part II. J MEMS 12:761–778Google Scholar

Copyright information

© Springer-Verlag 2005

Authors and Affiliations

  1. 1.Department of Mechanical EngineeringNational Chiao Tung UniversityHsinchuTaiwan

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