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Numerical analyses of peel demolding for UV embossing of high aspect ratio micro-patterning

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Abstract

Ultraviolet (UV) embossing, involving molding against micro-structured molds, is a quick and efficient method to mass produce high aspect ratio micro-features. A crucial challenge to the repeatability and large-scale application of this technique is successful demolding, which escalates in difficulty with increasing aspect ratio, due to increased polymer-mold mechanical interlocking. Some of the key factors affecting UV embossing include the crosslinked polymer shrinkage and material properties, interfacial strength between polymer to mold and the demolding method. This paper presents a new method to simulate the demolding of UV cured polymer from a nickel mold. Hyperelastic material model and rate-independent cohesive zone modeling were employed in the numerical simulation; linear elastic polymer response, although relatively easy to apply, was not adequate. Progressive shrinkage was implemented, leading to delamination of the polymer-mold interface. The subsequent peeling of the cured polymer from the mold was modeled with increasing prescribed displacement. The optimal shrinkage degree was found to increase from 0.92 to 1.9% with increasing mold aspect ratio (aspect ratio is defined as height to width ratio) from 5 to 10.

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References

  • ABAQUS (2004) Version 6.4, Theory and User Manuals I, II, III. Hibbitt, Karlsson and Sorensen, Inc., 1080 Main Street, Pawtucket, RI, 02860-4847, USA

  • ASTM Standard D638-03 (2003) Standard test method for tensile properties of plastics, ASTM International, West Conshohocken, PA

  • Agarwal M, Gunasekaran RA, Coane P et al (2005) Scum free patterning of SU-8 resist for electroforming applications. J Micromech Microeng 15:130–135. doi:10.1088/0960-1317/15/1/020

    Article  Google Scholar 

  • Anderson DG, Putnam D, Lavik EB et al (2005) Biomaterial microarrays: rapid, microscale screening of polymer-cell interaction. Biomaterials 26:4892–4897. doi:10.1016/j.biomaterials.2004.11.052

    Article  Google Scholar 

  • Bender M, Otto M, Hadam B et al (2000) Fabrication of nanostructures using a UV-based imprint technique. Microelectron Eng 57:233–236. doi:10.1016/S0167-9317(00)00304-X

    Article  Google Scholar 

  • Chan-Park MB, Neo WK (2003) Ultraviolet embossing for patterning high aspect ratio polymeric microstructures. Microsyst Technol 9:501–506. doi:10.1007/s00542-002-0289-0

    Article  Google Scholar 

  • Chan-Park MB, Gao JX, Koo HL (2003a) Surface characterization of nickel alloy plasma-treated by O2/CF4 mixture. J Adhes Sci Technol 17:1979–2004. doi:10.1163/156856103322584173

    Article  Google Scholar 

  • Chan-Park MB, Lam YC, Laulia P et al (2003b) Simulation and investigation of factors affecting high aspect ratio UV embossing. Langmuir 21:2000–2007. doi:10.1021/la035124e

    Article  Google Scholar 

  • Chan-Park MB, Yan YH, Neo WK et al (2003c) Fabrication of high aspect ratio Poly(ethylene glycol)-containing microstructures by UV embossing. Langmuir 19:4371–4380. doi:10.1021/la026967t

    Article  Google Scholar 

  • Cornec A, Scheider I, Schwalbe KH (2003) On the practical application of the cohesive model. Eng Fract Mech 70:1963–1987. doi:10.1016/S0013-7944(03)00134-6

    Article  Google Scholar 

  • Gale MT (1997) Replication. In: Herzig HP (ed) Micro-optics: elements, systems and applications, 1st edn. Taylor and Francis, London, pp 153–154

    Google Scholar 

  • Gao JX, Chan-Park MB, Xie DZ et al (2004) UV embossing of sub-micrometer patterns on biocompatible polymeric films using a focused ion beam fabricated TiN mold. Chem Mater 16:956–958. doi:10.1021/cm0342849

    Article  Google Scholar 

  • Gao JX, Yeo LP, Chan-Park MB et al (2006) Anti-stick post passivation of high-aspect ratio Silicon molds fabricated by deep-reactive ion etching. J MicroelectroMech S 15:84–93. doi:10.1109/JMEMS.2005.863795

    Article  Google Scholar 

  • Kilambi H, Reddy SK, Schneidewind L et al (2007) Copolymerization and dark polymerization studies for photopolymerization of novel acrylic monomers. Polymer (Guildf) 48:2014–2021. doi:10.1016/j.polymer.2007.02.006

    Article  Google Scholar 

  • Ogden RW (1972) Large deformation isotropic elasticity-on the correlation theory and experiment for incompressible rubberlike solids. Proc R Soc Lond Ser-A A 326:565–583

    Article  MATH  Google Scholar 

  • Otto M, Bender M, Hadam B et al (2001) Characterization and application of a UV-based imprint technique. Microelectron Eng 57:361–366. doi:10.1016/S0167-9317(01)00536-6

    Article  Google Scholar 

  • Rahulkumar P, Jagota A, Bennison SJ et al (1999) Polymer interfacial fracture simulations using cohesive elements. Acta Mater 47:4161–4169. doi:10.1016/S1359-6454(99)00276-1

    Article  Google Scholar 

  • Rahulkumar P, Jagota A, Bennison SJ et al (2000) Cohesive element modeling of viscoelastic fracture: application to peel testing of polymers. Int J Solids Struct 37:1873–1897. doi:10.1016/S0020-7683(98)00339-4

    Article  MATH  Google Scholar 

  • Scheider I (2001) Cohesive model for crack propagation analyses of structures with elastic-plastic material behavior: foundations and implementation. GKSS research center Geesthacht, Dept. WMS

  • Shvartsman FP (1991) Holographic optical elements by dry photopolymer embossing. Proc SPIE 1461:313–320. doi:10.1117/12.44742

    Article  Google Scholar 

  • Unger MA, Chou HP, Thorsen T et al (2000) Monolithic microfabricated valves and pumps by multilayer soft lithography. Science 288:113–116. doi:10.1126/science.288.5463.113

    Article  Google Scholar 

  • Xu XP, Needleman A (1994) Numerical simulations of fast crack growth in brittle solids. J Mech Phys Solids 42:1397–1434. doi:10.1016/0022-5096(94)90003-5

    Article  MATH  Google Scholar 

  • Yeo LP (2008) Demolding mechanics of micro-cast UV thermosets. Ph.D. Nanyang Technological University, Singapore

  • Yeo LP, Lam YC, Chan-Park MB et al (2005) Demolding of high aspect ratio polymeric micro-patterning. Int J Nanoscience 4:543–549. doi:10.1142/S0219581X05003462

    Article  Google Scholar 

  • Zhou WX, Chan-Park MB (2005) Large area UV casting using diverse polyacrylates of microchannels separated by high aspect ratio microwalls. Lab Chip 5:512–518. doi:10.1039/b419330j

    Article  Google Scholar 

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Acknowledgements

L. P. Yeo acknowledges the sponsorship of a graduate scholarship from the SMA-IMST program. This research was partially supported by an A*STAR (Singapore) grant (Project No. 042 114 0041).

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Authors and Affiliations

  1. Singapore-MIT Alliance, N2-B2C-15, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore

    L. P. Yeo, Y. C. Lam, Mary B. Chan-Park & D. E. Hardt

  2. Singapore Institute of Manufacturing Technology (SIMTech), 71 Nanyang Drive, Singapore, 638075, Singapore

    L. P. Yeo

  3. School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore

    S. C. Joshi & Y. C. Lam

  4. School of Chemical and Biomedical Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore

    Mary B. Chan-Park

  5. Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139-430, USA

    D. E. Hardt

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  1. L. P. Yeo
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  2. S. C. Joshi
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  3. Y. C. Lam
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  4. Mary B. Chan-Park
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  5. D. E. Hardt
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Correspondence to Y. C. Lam.

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Yeo, L.P., Joshi, S.C., Lam, Y.C. et al. Numerical analyses of peel demolding for UV embossing of high aspect ratio micro-patterning. Microsyst Technol 15, 581–593 (2009). https://doi.org/10.1007/s00542-008-0760-7

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  • DOI: https://doi.org/10.1007/s00542-008-0760-7

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