# 마이크로 광 조형에서 레이저 주사조건에 따른 광 경화성수지의 경화현상

• Published : 2004.03.01

#### Abstract

Micro-stereolithography technology has made it possible to fabricate a freeform 3D microslructure. This technology is based on conventional stereolithography, in which a UV laser beam irradiates the open surface of a UV-curable liquid photopolymer, causing it to solidify. In micro-stereolithography, a laser beam of a few $\mu m$ diameter is used to solidify a very small area of the photopolymer. This is one of the key technological elements, and can be achieved by using a focusing lens. Thus, the solidification phenomena of the liquid photopolymer must be carefully investigated. In this study, the photopolymer solidification phenomena in response to variations in the scanning pitch of a focused laser beam was investigated experimentally. The effect of layer thickness on the solidification width and depth was also examined. These studies were conducted under the conditions of relatively lower laser power and relatively higher scanning speed. Moreover, the photopolymer solidification phenomena for the relatively higher laser power and lower scanning speed was investigated, too. In this case, comparing to the case of lower laser power and higher scanning speed, the photopolymer absorbed large amount of irradiation energy of the laser beam. These results were compared with those obtained from a photopolymer solidification model. From these results, a new laser-scanning scheme was proposed according to the shape of the 3D model. Samples by each method were fabricated successfully.

#### References

1. Maruo, S. and Ikuta,K., 'Movable mirostructures made by two-photon three-dismensional microfabrication,' Proc. of International Symposium on Micro Mechatronics and Human Science, 1999
2. Maruo, S. and Ikuta, K., 'Fabrication of freely movable microstructures by using two-photon three-dimensional microfabrication,' Proceedings of SPIE, Vol. 3937, 2000 https://doi.org/10.1117/12.382800
3. Zissi, S., Bertsch, A., Jeijequel, J. Y., Corbel, S., Lougnot, D. J. and Andre, J. C., 'Stereolithography and microtechnoiques,' Microsystem Technologies, 2, pp. 97-102, 1996 https://doi.org/10.1007/BF02447758
4. Scheffer, P., Bertsch, A., Corbel, S., Jejequel, A. J. Y. and Andre, J. C., 'Industrial photochemistry XXIV. Relations between light flux and polymerized depth in laser stereolithography,' Journal of Photochemistry and Photobiology A:Chemistry, 107, pp. 283-290, 1997 https://doi.org/10.1016/S1010-6030(97)00062-2
5. Zhang, X., Ziang, X. N. and Sun, C., 'Micro-stereolithography of polymeric and ceramic microstructure,' Sensors and Actuators, Vol. 77, pp. 149-156, 1999 https://doi.org/10.1016/S0924-4247(99)00189-2
6. Nakamoto, T., Yamaguchi, K., Abraha, P. A. and Mishima, K., 'Manufacturing of three-dimensional micro-parts by UV-laser-induced polymerization,' J. Micromech. Microeng, 6, pp. 240-253, 1996 https://doi.org/10.1088/0960-1317/6/2/006
7. Lee, Eun-dok, Sim, Jae-Hyung and Park, In-Hwan, 'Cure Properties in Photopolymer for Stereolithography according to Variance of Laser Beam Size,' Journal of the Korean Society of Precision Engineering, Vol. 20, No. 2, 2003
8. Jacobs, Paul F., 'Rapid Prototyping & Manufacturing - Fundamentals of Stereolithography,' Society of Manufacturing Engineers, 1992