• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.11a
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• pp.155-156
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• 2007

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.11a
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• pp.499-500
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• 2007

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.676-679
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• 2005

Nano imprint Lithography (NIL) is regarded as one of the next-generation lithography technologies with EUV lithography, immersion lithography, Laser interference lithography. Because a Si wafer stamp and a quartz stamp, used to imprinting usually are very expensive and easily broken, it is suggested that master stamp is duplicated by PDMS and the PDMS stamp uses to imprint .For using the PDMS stamp, a thermally curable monomer resin was used for the imprinting process to lower pressure and temperature. As a result, NIL patterns were successfully fabricated.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.207-208
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• 2007

Recently, high performance microelectronic devices are designed in multi-layer structure in order to make dense wiring of metal conductors in compact size. Imprint lithography have received significant attention due to an alternative technology for photolithography on such devices. In this work, we synthesized dielectric composite materials based on epoxy resin, and investigated their thermal stabilities and dynamic mechanical properties for thermal imprint lithography. In order to enhance the mechanical properties and toughness of dielectric material, various modified polyetherimide(PEI) was applied in the resin system. Curing behaviours, thermal stabilities, and dynamic mechanical properties of the dielectric materials cured with various conditions were studied using dynamic differential scanning calorimetry (DSC), thermo gravimetric analysis (TGA), and Universal Test Method (INSTRON).

• Proceedings of the Materials Research Society of Korea Conference
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• 2007.11a
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• pp.70.2-70.2
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• 2007

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1489-1492
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• 2005

Compared to other nano-patterning techniques, Nano imprint Lithography (NIL) has some advantages of high throughput and low process cost. To imprint low temperature and pressure, UV Nano imprint Lithography, which using the monomer based UV curable resin is suggested. Because fabrication of high fidelity pattern on topographical substrate is difficult, bi-layer Nano imprint lithography, which are consist of easily removable under-layer and imprinted pattern, is being used. If residual layer is not remained after imprinting, and under-layer is removed by oxygen RIE etching, we might be able to fabricate the bi-layer pattern for easy lift-off process.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.7
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• pp.67-73
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• 2020

Shrinkage is inevitable in the curing of resins during the nanoimprint process. The degree of shrinkage that occurs as the resin transforms from a viscous liquid to solid differs depending on the type of resin. However, if the cured material is repeatedly cured using the same material, constant shrinkage can be confirmed. In this study, the pattern of change was observed by repeatedly performing the nanoimprint process using a resin with a constant shrinkage rate. The observed pattern for the change of shape was made using a triangular pyramid-shaped aluminum master mold and a flexible replica mold made from the master. Shrinkage that results from the nanoimprint process occurs linearly in the longitudinal direction of the pattern and can be predicted by simple calculations. The change of the pattern due to shrinkage occurred as expected. If the shrinkage rate remains constant, various patterns can be manufactured with high accuracy by correcting these changes before producing a specific shape. This study confirms that the pattern of the desired angle can be obtained by performing the repeated imprint without having to manufacture a master mold.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.1
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• pp.104-109
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• 2013

In order to apply nano imprint technology in large area process, roller pressing is promising because of its low cost and high productivity. When pressing mold by roller, liquid resin is locally squeezed between mold and substrate. In this study, the main focus is to understand which process parameter affects residual layer. To do this, a simple analytical model was introduced. Especially, we consider the aspect ratio of patterns as essential cause of variation of the thickness in the equation. As a result, when the aspect ratio of pattern in the mold increases, the thickness of residual layer also increases. In conclusion, we show that the uniformity of residual layer could be accomplished by the control of velocity and pressing force in roller pressing imprint process.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.242-242
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• 2006

Increasingly complex tasks are performed by computers or cellular phone, requiring more and more memory capacity as well as faster and faster processing speeds. This leads to a constant need to develop more highly integrated circuit systems. Therefore, there have been numerous studies by many engineers investigating circuit patterning. In particular, PCB including module/package substrates such as FCB (Flip Chip Board) has been developed toward being low profile, low power and multi-functionalized due to the demands on miniaturization, increasing functional density of the boards and higher performances of the electric devices. Imprint lithography have received significant attention due to an alternative technology for photolithography on such devices. The imprint technique. is one of promising candidates, especially due to the fact that the expected resolution limits are far beyond the requirements of the PCB industry in the near future. For applying imprint lithography to FCB, it is very important to control thermal properties and mechanical properties of dielectric materials. These properties are very dependent on epoxy resin, curing agent, accelerator, filler and curing degree(%) of dielectric materials. In this work, the epoxy composites filled with silica fillers and cured with various accelerators having various curing degree(%) were prepared. The characterization of the thermal and mechanical properties wasperformed by thermal mechanical analysis (TMA), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), rheometer, an universal test machine (UTM).

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1939-1943
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• 2008

Deformation of a mold is measured and analyzed in alignment and curing processes of UV-Imprint Lithography. We are focused on mold deformation caused by a UV resin, which is laminated between a mold and a target glass-panel. The UV resin is viscous in case of liquid state, and the resin will be solidified when being exposed by the ultra-violet light. The viscosity of the resin causes shear force on the mold during the alignment process. Moreover, the shrinkage during phase change from liquid to solid may cause residual stress on the mold. The experiments for measuring temperature and strain are made during alignment and curing process. Strain-gages and thermocouples are used for measuring the strain and variation of temperature on several points of the mold, respectively. The deformation of mold is also simulated and analyzed. The simulation results are compared with the experiments. Finally, sources of alignment errors in large area UV-nanoimprint lithography are discussed.