Browse > Article
http://dx.doi.org/10.3795/KSME-A.2002.26.11.2450

Microlens Fabrication Method by the Modified LICA Process  

Lee, Sung-Keun (포항공과대학교 기계공학과)
Lee, Kwang-Cheol (포항공과대학교 대학원 기계공학과부)
Lee, Seung-S. (포항공과대학교 대학원 기계공학과부)
Publication Information
Transactions of the Korean Society of Mechanical Engineers A / v.26, no.11, 2002 , pp. 2450-2456 More about this Journal
Abstract
Microlenses and microlens arrays are fabricated using a novel fabrication technology based on the exposure of a resist (usually PMMA) to deep X-rays and subsequent thermal treatment. The fabrication technology is very simple and produces microlenses and microlens arrays with good surface roughness (less than 1 nm). The molecular weight and glass transition temperature of PMMA is reduced when it is irradiated with deep X-rays. The microlenses is produced through the effects of volume change, surface tension, and reflow during thermal treatment of irradiated PMMA. The geometry of the microlens is determined by parameters such as the X-ray dose applied to the PMMA, the diameter of the microlens, along with the heating temperature, heating time, and cooling rate in the thermal treatment. Microlenses are produced with diameters ranging from 30 to 1500 ${\mu}{\textrm}{m}$. The modified LIGA process is used not only to construct hemispherical microlenses but also structures that are rectangular-shaped, star-shaped, etc.
Keywords
PMMA; Microlens; LIGA; Class Transition Temperature; MEMS;
Citations & Related Records
Times Cited By KSCI : 1  (Citation Analysis)
연도 인용수 순위
1 Becker, E. W., Betz, H., Ehrfcld, W, Glashauser, W, Heuherger, A., Michel, M. J., Miinchmeyer, D., Pongratz, S. and Siernen, P. R., 1992, 'Production of Separation Nozzle Systems for Uranium Enrichment by a Combination of X-Ray Lithography and Galvanoplastics,' Naturwissenschaften, Vol. 69, pp. 520-523   DOI
2 Ruther, P., Gerlach, B., Gottert, J., Ilie, M., Mohr, J., Muller A. and OBmann, C., 1997, 'Fabrication and Characterization of Microlenses Realized by a Modified LIGA process,' Pure Appl. Opt., Vol. 6, pp. 643-653   DOI   ScienceOn
3 King, C. R., Lin, L. Y. and Wu, M. C., 1996, 'Out-of-plane Refractive Microlens Fabricated by Surface Micromachining,' IEEE Photonics Technology Letters, Vol. 8, No. 10, pp. 1349-1351   DOI   ScienceOn
4 Schulze, J., Ehrfeld, W., HoBfeld, J., Klaus, M., Kufner, M., Kufner, S., Muller, H. and Picard, A., 1999 'Parallel Optical Interconnection using Self-Adjusting Microlenses on Injection Molded Ferrules Made by LIGA Technique,' Proc. SPIE, Vol. 37, pp. 562-571
5 Young, R. J. and Lovell, P. A., 1991, Introduction to Polvmers, Chapman & Hall
6 Kohler, U., Guber, A. E., Bier, W. and Heckele, M., 1996, 'Fabrication of Microlenses by Plasmaless Isotropic Etching Combined with Plastic Moulding,' Sensors and Actuactors A, Vol. 53, pp. 361-363   DOI   ScienceOn
7 Liu. Z., Bouamrane, F., Roulliay, M., Kupka, R. K., Labeque, A. and Megtert, S., 1998, 'Resist Dissolution Rate and Inclined-Wall Structures in Deep X-Ray Lithography,' J. Micromech, Microeng. , Vol. 8, pp. 298-300   DOI   ScienceOn