We report on a screen printing fabrication process for large-area SU-8 layers utilised for the preparation of microstructures in display devices such as microelectronic, electrowetting or bistable devices. The screen printing method has been selected for its effectiveness and simplicity over traditionally used spin-coating ones. Layers and microstructures produced thereof have shown proper homogeneity. Relationships between screen parameters to coating thickness have been established. Coating on an ITO (indium tin oxide) hydrophobic surface is possible when surface has been treated by UV/Ozone to increase its aqueous ability. To this end, the hydrophilic microstructure grids have been successfully built on a hydrophobic layer by screen printing and traditional lithography processes. Compared to conventional spin-coating methods, the screen printing method offers the advantages of simple, cheap and fast fabrication, and is especially suitable for large-area display fabrication
1. Gelorme, J.D., Cox, R.J., and Gurrierez, S.A. (1989). Photoresist composition and printed circuit boards and packages made therewith. US4882245A.
2. You, H., and Steck, A.J. (2013). Lightweight electrowetting display on ultrathin glass substrate. Society for Information Display, 21(5), 192-197.
3. MicroChem (2001). SU-8 Negative Tone Photoresist Formulations 50-100, Data sheets.
4. Luurtsema, G.A. (1997). Spin Coating for Rectangular Substrates. University of California.
5. Garcano, G., Ceriani M., and Soglio, F. Spin coating with high viscosity photo-resist on square substrates - Applications in the thin film hybrid microwave integrated circuit field. Microelectronics International, 10(3), 12-20.
6. Gale, B.K, Eddings, M.A., Sundberg, S.O., Hatch, A., Kim, J., and Ho, T. (2007). Low- Cost MEMS Technologies. Elsevier.
7. Yue, W., Li, C.W., Xu, T., and Yang, M. (2013). Screen printing of solder resist as master substrates for fabrication of multi-level microfluidic channels and flask-shaped microstructures for cell-based applications. Biosensors and Bioelectronics, 15(41), 675-683.
8. Levario, T. J., Zhan, M., Lim, B., Shvartsman, S.Y., and Lu, H. (2013). Microfluidic trap array for massively parallel imaging of Drosophila embryos. Nature America, 8(4), 721-736.
9. Moser, Y., Forti, R., Jiguet, S., Lehnert, T., and Gijs, M. (2010). Suspended SU-8 structures for monolithic microfluidic channels. Microfluid Nanofluid, 10(1), 219-224.
10. Liu, J., Cai, B., Zhu, J., Ding, G., Zhao, X., Yang, C., and Chend, D. (2004). Process research of high aspect ratio microstructure using SU-8 resist. Microsystem Technologies, 10(4), 265-268.
11. Li, Y., Xiadong, W., Chong, L., Zhifeng, L., Denan, C., and Dehui, Y. (2005). Swelling of SU-8 structure in Ni mold fabrication by UV-LIGA technique. Microsystem Technologies, 11(12), 1272-1275.
12. Dai, W., Lian, K., and Wang, W. (2004). A quantitative study on the adhesion property of cured SU-8 on various metallic surfaces. Microsystem Technologies, 11(7), 526-534.
13. Dey, P., Pramanick, B., RaviShankar, A., Ganguly, P., and Das, S. (2010). Microstructuring of SU-8 resist for MEMS and bio-applications. International Journal on Smart Sensing and Intelligent Systems, 3(1), 118-129.
14. Mao, X., Yang, J., Ji, A., and Yang, F. (2013). Two new Methods to Improve the Lithography Precision for SU-8 Photoresist on Glass Substrate. Journal of Microelectromechanical Systems, 22(1), 124-130.
15. Ahani, A., Saadati-Fard, L., Sodagar, A. M., and Boroumad F. A. (2011). Flexible PET/ ITO Electrode Array for Implantable Biomedical Applications. 33rd Annual International Conference of the IEEE EMBS, 30 August-03 September 2011, (2878-81), Boston, IEEE.
16. Li, P.C.H. (2005). Microfluidic Lab-on-a-Chip for Chemical and Biological Analysis and Discovery. Boca Raton, FL. CRC Press.
17. Handbook Tech Tips for Screen Printers. (2001). USA: SaatiPrint.
18. Campo, A., and Greiner, C. (2007). SU-8: a photoresist for high-aspect-ratio and 3D submicron lithography. Journal of Micromechanics and Microengineering, 17(6). 81-95.
19. Bikerman, J. (1941). Method of measuring contact angles. Ind. Eng. Chem. Anal. Ed., 13(6), 443-444.
20. SU-8 2000 Permanent Epoxy negative photoresist Processing guidelines for SU-8 2100 and SU8-2150. MicroChem.
21. Lide, D.R. (2005). CRC Handbook of Chemistry and Physics. CRC Press.
22. Willfahrt, A., and Stephens, J. (2010). Optimizing stencil thickness and ink film deposit. International Circular of Graphic Education and Research, 6-17.
23. Sarl, G. (2007). GM 1075 Technical Datasheet.
24. Atthi, N., Nimittrakoolchai, O., Jeamsaksiri, W., Supothina, S., Hruanun, C., and Poyai, A. (2009). Study of optimization condition for spin coating of the photoresist film on rectangular substrate by taguchi design of an experiment. Songlanakarin Journal of Science and Technology, 31(3), 331-335.
25. Snodgrass, T., and Newquist, C. (1994). Extrusion coating of polymers for next generation, large-area FPD manufacturing. Society for Information Display, 40-45.