• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2003.06a
• /
• pp.1224-1226
• /
• 2003

In this work, we developed a high resolution printing technique based on transferring a pattern from a PDMS stamp to a Pd and Au substrate by microcontact printing Also, we fabricated various 2D metallic and polymeric nano patterns with the feature resolution of sub-micrometer scale by using the method of microcontact printing (${\mu}$CP) based on soft lithography. Silicon masters for the micro molding were made by e-beam lithography. Composite poly(dimethylsiloxane) (PDMS) molds were composed of a thin, hard layer supported by soft PDMS layer. From this work, it is certificated that composite PDMS mold and undercutting technique play an important role in the generation of a clear SAM nanopattern on Pd and Au substrate.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2002.11a
• /
• pp.342-345
• /
• 2002

As the size of chip components and module decreases, new patteming method for fine line and geometry is needed. So far, in LTCC(Low Temperature Cofired Ceramic) process, screen printing method has been used generally. But screen printing method has some disadvantages as follows. First, the geometry including line, vias, etc. smaller than $100{\mu}m$ can't be evaluated easily. Second, the patterned dimension is different from designed value, which makes distortion in charactersitics of not only chip components but also modules. Thick film lithography has advantages of thick film screen printing process, low cost and thin film process, fine line feasibility. Using this method, the line with $30{\mu}m$ width and the geometry with expected dimension can be evaluated. In this study, the fine line with $35{\mu}m$ line/space is formed and the embedded capacitor with very small tolerance is developed using thick film lithography.

• Journal of the Korean Graphic Arts Communication Society
• /
• v.28 no.2
• /
• pp.31-44
• /
• 2010

Ever since the introduction of offset lithography, an operator have looked for ways to improve the process by reducing need for dampening solution. Lithography like off-set printing is processed using the repellent properties between water and oil, so all inks for lithography printing must work with dampening solution. The dampening solution may cause the emulsification of ink by the printing pressure in the printing nip. Emulsified ink changed viscosity, tack and causes problems such as bad transfer, uniform density and printed mottle. For a high quality web printing, we studied the effect of emulsified heat-set web inks on the printability, such as amount of ink transfer, printed density and uniformity. For this study, we were carried out by using IGT printability tester C1. For determination of ink properties using the spread meter and Thwing Albert Ink-o-meter, and using the densitometer and image analysis for printed quality determination. The experimental results of this study, we look forward to can be used as the basis for improve of the web print quality.

• Proceedings of the Korean Printing Society Conference
• /
• 1998.10a
• /
• pp.7-15
• /
• 1998

• Korean Journal of Materials Research
• /
• v.19 no.4
• /
• pp.224-227
• /
• 2009

Nanofabrication is an essential process throughout industry. Technologies that produce general nanofabrication, such as e-beam lithography, dip-pen lithography, DUV lithography, immersion lithography, and laser interference lithography, have drawbacks including complicated processes, low throughput, and high costs, whereas nano-transfer printing (nTP) is inexpensive, simple, and can produce patterns on non-plane substrates and multilayer structures. In general nTP, the coherency of gold-deposited stamps is strengthened by using SAM treatment on substrates, so the gold patterns are transferred from stamps to substrates. However, it is hard to apply to transfer other metallic materials, and the existing nTP process requires a complicated surface treatment. Therefore, it is necessary to simplify the nTP technology to obtain an easy and simple method for fabricating metal patterns. In this paper, asnTP process with poly vinyl alcohol (PVA) mold was proposed without any chemical treatment. At first, a PVA mold was duplicated from the master mold. Then, a Mo layer, with a thickness of 20 nm, was deposited on the PVA mold. The Mo deposited PVA mold was put on the Si wafer substrate, and nTP process progressed. After the nTP process, the PVA mold was removed using DI water, and transferred Mo nano patterns were characterized by a Scanning electron micrograph (SEM) and Energy Dispersive spectroscopy (EDS).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2006.11a
• /
• pp.109-109
• /
• 2006

Screen printing (SP) metal contact is typically applied to the solar cells for mass production. However, SP metal contact has low aspect ratio, low accuracy, hard control of the substrate penetration and unclean process. On the other hand, photo lithograpy (PL) metal contact can reduce defects by metal contact. In this investigation, PL metal contact was obtained the multi-layer structure of Ti/Pd/Ag by e-beam process. We applied SP metal contact and PL metal contact to single crystalline silicon solar cells, and demonstrated the difference of conversion efficiency. Because PL metal contact silicon solar cell has Jsc (short circuit current density) better than silicon solar cell applied SP metal contact.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2010.05a
• /
• pp.30.1-30.1
• /
• 2010

Hydrogen silsesquioxane (HSQ)는 spin-on glass (SOG)의 일종으로 spin-coating이 가능하며 $400^{\circ}C$ 이상의 고온에서의 어닐링을 통해 silica로 변환되는 물질이다. 이 물질은 가시광선 영역에서 95% 이상의 높은 투과도를 나타내며 산화물로의 변환 공정이 간단하며 표면 개질이 용이하기 때문에 나노 바이오, 반도체, 광전자 소자 등의 다양한 분야로의 적용이 기대되는 물질이다. 최근 나노 기술의 발전에 따라 다양한 나노 구조물을 이용하여 소자들의 효율을 향상시키는 연구가 활발하게 진행되고 있다. 따라서 HSQ를 이용하는 소자의 효율을 높이기 위해서는 쉽고 간단하면서 생산성이 높은 HSQ 나노 구조물 제작 기술에 대한 연구가 필요하다. 현재 개발된 대면적 HSQ 나노 구조물 제작 기술로는 e-beam lithography, x-ray lithography, room temperature nanoimprint lithography 등이 있다. 하지만 이와 같은 나노 패터닝 기술들은 생산성이 낮거나 공정이 복잡한 단점이 있다. 본 연구에서는 poly(dimethylsiloxane) (PDMS) mold를 이용한 직접 printing 기술을 통해 HSQ 나노 구조물을 제작하는 기술을 개발하였다. 이 기술은 대면적에 간단한 기술로 HSQ 나노 패턴을 제작할 수 있으며 master mold의 패턴이 그대로 HSQ layer로 전사되기 때문에 제작이 까다로운 아날로그 패턴도 손쉽게 제작할 수 있는 장점을 가지고 있다. 따라서 이와 같은 HSQ 직접 printing 기술을 이용하여 HSQ 아날로그 나노 패턴을 제작하고 이의 응용기술에 대한 연구를 진행하였다.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2012.10a
• /
• pp.339-340
• /
• 2012

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2012.10a
• /
• pp.93-94
• /
• 2012

• Journal of the Korean Society for Precision Engineering
• /
• v.20 no.4
• /
• pp.5-11
• /
• 2003