• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.560-563
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• 2004

Invar is a compound metal of Fe-Ni system and contain 36％ Ni. The most distinction characteristic of Invar is the coefficient of thermal expansion is 1.0 10$^{-6}$ /$^{\circ}C$. That is a tenth of general steel material. This low thermal expansion characteristic of Invar is applied to the missile, aircraft, monitor CRT and frontier display's shadow mask such as FED and OLED. The usage of the Invar shadow mask for display is increasing due to the requirement of larger size and flatness monitor. The Invar shadow mask is machined by two ways electro-forming and laser now. However the electro-forming takes a too long time and the laser machining is accompanied with Burr. In this study, PEMM(pulse electrochemical micro machining) is conducted to machine the micro hole to the Invar and 80${\mu}{\textrm}{m}$ hole was machined.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1046-1049
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• 2006

We proposed a simplified fabrication structure and method which can provide separate Red (R), Green (G), Blue (B), and White (W) OLED pixels with 2 metal-mask changes in emitting layer fabrication inspired from the structure of multi-layer white OLED and carrier blocking mechanism. A red emission layer for the R and W pixel with 1st mask, and then a blue emission layer with hole blocking layer for the B and W pixel with 2nd mask, and finally a common green emission layer were deposited sequentially. We expect that this concept would be very useful to the actual fabrication of multi-color OLED display although additional optimization is needed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1277-1280
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• 2005

A high-aspect-ratio and high-resolution stainless steel shadow mask for organic thin-film transistors (OTFTs) circuit has been fabricated by a new method which combines photochemical machining, micro-electrical discharge machining (micro-EDM), and electrochemical etching (ECE). First, connection lines and source-drain holes are roughly machined by photochemical etching, and then the part of source and drain holes is finished by the combination of micro-EDM and ECE processes. Using this method a $100\;\mu{m}$ thick stainless steel (AISI 304) shadow mask for inverter can be fabricated with the channel length of $30\;\mu{m}\;and\;10\;\mu{m}\;respectively.\;The\;width\;of\;connection line\;is\;150\;\mu{m}$. The aspect ratio of the wall is about 5 and 15, respectively. Metal lines and source-drain electrodes of OTFTs were successfully deposited through the fabricated shadow mask.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.3
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• pp.227-231
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• 2013

Electrodeionization is a hybrid separation process of electrodialysis and ion exchange to produce high purity water under electric field. This article provides a fabrication result of hole patterned metal electrode for elecrodeionization system. The hole patterns have been fabricated by nanosphere lithography (NSL). The technique utilizes the self-assembled nanospheres as lens-mask patterns and collimated laser beam source. The hole patterns have a periodic array structure. The images of hole pattern on metal electrode prepared were observed by SEM. We believe that the periodic hole patterned metal electrode structure is a useful device applicable for metal mat electrode in electrodeionization system.

• The Journal of Advanced Prosthodontics
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• v.11 no.5
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• pp.286-296
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• 2019

PURPOSE. The aim was to study the masking ability of high-translucency monolithic zirconia and provide guidance in selecting resin luting cements in order to mask discolored substrates. MATERIALS AND METHODS. 160 high-translucency zirconia specimens were divided into 32 groups depending on their thickness and shades. Using five shades of try-in paste, the specimens were luted onto the substrates (Co-Cr, precious-metal, opaque porcelain-sintered Co-Cr, opaque porcelain-sintered precious-metal, and 5M3-shade zirconia). All CIELAB color parameters were measured and statistically analyzed. RESULTS. Zirconia shade and thickness and try-in paste shade affected CIELAB color parameters (P=.000) in different substrates groups, and there were interactions among these factors (P=.000). All five try-in paste shades can be chosen to achieve ${\Delta}E$ values of zirconia with 1.2 - 1.5 mm for masking dark-tooth-like 5M3-shade and zirconia with 1.5 mm for masking precious-metal groups < 2.6. Only suitable try-in paste shades were used, can ${\Delta}E$ values that less than 2.6 be achieved when applied translucent monolithic zirconia with 0.7-1.0 mm for masking dark-tooth-like 5M3-shade and zirconia with 0.7 - 1.2 mm for masking precious-metal groups. CONCLUSION. Choosing suitable resin cement shades is necessary for high-translucency monolithic zirconia to achieve ideal masking ability (${\Delta}E$ < 2.6) on the dark-tooth.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.219-222
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• 2003

Self-Assembled Monolayers(SAMs) by alkanethiol adsorption to thin metal film are widely being investigated for applications as coating layer for anti-stiction or friction reduction and in fabrication of micro structure of molecular and bio molecular. Recently, there have been many researches on micro patterning using the advantages of very thin thickness and etching resistance in selective etching of thin metal film of Self- Assembled Monolayers. In this report, we present the micromachining thin metal film by Mask-Less laser patterning of alknanethiolate Self-Assembled Monolayers.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.10a
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• pp.361-362
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• 2012

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.10a
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• pp.279-280
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• 2009

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.502-502
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• 2007

Current thin film process using memory device fabrication process use expensive processes such as manufacturing of photo mask, coating of photo resist, exposure, development, and etching. However, direct printing technology has the merits about simple and cost effective processes because inks are directly injective without mask. And also, this technology has the advantage about fabrication of fine pattern line on various substrates such as PCB, FCPB, glass, polymer and so on. In this work, we have fabricated the fine and thick metal pattern line for the electronic circuit board using metal ink contains Ag nano-particles. Metal lines are fabricated by two types of printing methods. One is a conventional printing method which is able to quick fabrication of fine pattern line, but has various difficulties about thick and high resolution DPI(Dot per Inch) pattern lines because of bulge and piling up phenomenon. Another(Second) methods is sequential printing method which has a various merits of fabrication for fine, thick and high resolution pattern lines without bulge. In this work, conductivities of metal pattern line are investigated with respect to printing methods and pattern thickness. As a result, conductivity of thick pattern is about several un.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.881-884
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• 2004

The robust and large-area applicable metal shadow masks with a high aspect ratio more than 20 are fabricated by a combination of micro-electro-discharge machining (${\mu}$-EDM) and electro chemical etching (ECE). After defining S/D contacts using a 100 ${\mu}m$ thick stainless steel shadow mask, the top-contact pentacene TFTs with channel length of 5 ${\mu}m$ showed routinely the results of mobility of 0.498 ${\pm}$ 0.05 $cm^2$/Vsec, current on/off ratio of 1.6 ${times}$ $10^5$, and threshold voltage of 0 V. The straightly defined atomic force microscopy (AFM) images of channel area demonstrated that shadow effects caused by the S/D electrode deposition were negligible. The fabricated pentacene TFTs have an average channel length of 5 ${\pm}$ 0.25 ${\mu}m$.