Korea-Australia Rheology Journal

The Korean Society of Rheology (한국유변학회)
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Fabrication of micro injection mold with modified LIGA micro-lens pattern and its application to LCD-BLU

  • Kim, Jong-Sun (Precision Mold Team, Korea Institute of Industrial Technology (KITECH)) ;
  • Ko, Young-Bae (Precision Mold Team, Korea Institute of Industrial Technology (KITECH)) ;
  • Hwang, Chul-Jin (Precision Mold Team, Korea Institute of Industrial Technology (KITECH)) ;
  • Kim, Jong-Deok (Precision Mold Team, Korea Institute of Industrial Technology (KITECH)) ;
  • Yoon, Kyung-Hwan (Mechanical Engineering, Dankook University)
  • Published : 2007.11.30
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Abstract

The light guide plate (LGP) of LCD-BLU (Liquid Crystal Display-Back Light Unit) is usually manufactured by forming numerous dots by etching process. However, the surface of those etched dots of LGP is very rough due to the characteristics of etching process, so that its light loss is relatively high due to the dispersion of light. Accordingly, there is a limit in raising the luminance of LCD-BLU. In order to overcome the limit of current etched-dot patterned LGP, micro-lens pattern was tested to investigate the possibility of replacing etched pattern in the present study. The micro-lens pattern fabricated by the modified LiGA with thermal reflow process was applied to the optical design of LGP. The attention was paid to the effects of different optical pattern type (i.e. etched dot, micro-lens). Finally, the micro-lens patterned LGP showed better optical qualities than the one made by the etched-dot patterned LGP in luminance.

Keywords

References

  1. Becker, E.W., W. Ehrfeld, P. Hagman, A. Mauser and D. Münchmeyer, 1986, Fabrication of microstructures with high aspect ratios and structural heights by synchrotron radiation lithography, galvanoforming, and plastic moulding (LIGA process), Microelectron. Eng. 4(1), 35-56 https://doi.org/10.1016/0167-9317(86)90004-3
  2. Chang, N., I. Choi and H. Shim, 2004, SDLS: Dynamic backlight luminance scaling of liquid crystal display, IEEE TRANSACTIONS ON VERY LARGE SCALE INTEGRATION (VLSI) SYSTEMS 12(8), 837-846 https://doi.org/10.1109/TVLSI.2004.831472
  3. Hwang, C.J., Y.B. Ko, S.Y. Ha, G.H. Lee and Y.M. Heo, 2005, Micro injection mold fabrication with modified LIGA microlens pattern and its application to LCD-BLU, 21st Annual Meeting of the Polymer Processing Society
  4. Lin, L., T.K. Shia and C.J. Chiu, 2000, Silicon-processed plastic micropyramids for brightness enhancement applications, J. Micromech and Microeng. 10, 395-400 https://doi.org/10.1088/0960-1317/10/3/314
  5. Lin, L., C.J. Chiu, W. Bacher and M. Heckele, 1996, Microfabrication using silicom mold inserts and hot embossing, 7th International symposium on Micro Machine and Human Science, 67-71
  6. Malek, C.K. and V. Saile, 2004, Applications of LIGA technology to precision manufacturing of high-aspect-ration micro-components and -systems: a review, Microelectronics Journal 35, 131-143 https://doi.org/10.1016/j.mejo.2003.10.003
  7. Nagahara, T. and A. Fukui, 2001, Light-guide plate for liquid crystal display, Matsushita Technical Journal 47(3), 2-6
  8. Popovic, Z.D., R.A. Sprague and G.A.N. Connell, 1998, Technique for monolithic fabrication of microlens arrays, 27(7), Applied Optics, 1281-1284 https://doi.org/10.1364/AO.27.001281
  9. Ruther, P., B. Gerlachy, J. Götterty, M. Iliez, J. Mohry, A. Müllery and C. OBmanny, 1997, Fabrication and characterization of microlenses realized by a modified LIGA process, Pure Appl. Opt. 6, 643-653 https://doi.org/10.1088/0963-9659/6/6/006
  10. Seidel, H., 1990, The mechanism of anisotropic, electrochemical silicon etching in alkaline solutions, Solid-State Sensor and Actuator Workshop, 4th Technical Digest., IEEE, 86-91
  11. Wu, M.H. and G.M. Whitesides, 2002, Fabrication of two-dimensional arrays of microlenses and their applications in photolithography, J. Micromech and Microeng 12, 747-758 https://doi.org/10.1088/0960-1317/12/6/305