• Korean Journal of Materials Research
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• v.23 no.10
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• pp.586-591
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• 2013

The printing of nanomaterials onto certain substrates is one of the key technologies behind high-speed interconnection and high-performance electronic devices. For the printing of next-generation electronic devices, a printing process which can be applied to a flexible substrate is needed. A printing process on a flexible substrate requires a lowtemperature, non-vacuum process due to the physical properties of the substrate. In this study, we obtained well-ordered Ag nanowires using modified gravure printing techniques. Ag nanowires are synthesized by a silver nitrate ($AgNO_3$) reduction process in an ethylene glycol solution. Ag nanowires were well aligned by hydrodynamic force on a micro-engraved Si substrate. With the three-dimensional structure of polydimethylsiloxane (PDMS), which has an inverse morphology relative to the micro-engraved Si substrate, the sub-micron alignment of Ag nanowires is possible. This technique can solve the performance problems associated with conventional organic materials. Also, given that this technique enables large-area printing, it has great applicability not only as a next-generation printing technology but also in a range of other fields.

• Proceedings of the Materials Research Society of Korea Conference
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• 2010.05a
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• pp.19.1-19.1
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• 2010

The process of manufacturing printed electronics using printing technology is attracting attention because its process cost is lower than that of the conventional semiconductor process. This technology, which offers both a lower cost and higher productivity, can be applied in the production of organic TFT (thin film transistor), solar cell, RFID(radio frequency identification) tag, printed battery, E-paper, touch screen panel, black matrix for LCD(liquid crystal display), flexible display, and so forth. In general, in order to implement printed electronics, narrow width and gap printing, registration of multi-layer printing by several printing units, and printing accuracy of under $20\;{\mu}m$ are all required. These electronic products require high precision to the degree of tens of microns - in a large area with flexible material, and mass productivity at low cost. As such, the roll-to-roll printing process is attracting attention as a mass production system for these printed electronic devices. For the commercialization of this process, two basic electronic ink technologies, such as conductive ink and polymers, and printing equipment have to be developed. Therefore, this paper addressed basis design and test to develop fine patterning equipment employing the roll-to-roll printing equipment and electronic ink.

• Laser Solutions
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• v.13 no.2
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• pp.6-9
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• 2010

In printed electronics, printing rolls are used to transfer electronic ink onto a flexible substrate. Generally printing rolls are being made by the indirect laser method which is based on the etch process, thus not environment-friendly and not suitable for making a large printing roll. For the pursuit of making a large printing roll for mass printing of electronic devices, we have directly engraved micro-patterns into a Zn plated printing roll using a 30W pulse-modulated fiber laser. We have successfully engraved line patterns ranging from about 15-30${\mu}m$ in width.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.9
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• pp.571-575
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• 2016

Recently, there has been much focus on the controlled alignment and patterning process of nanowires for nanoelectronic devices. A simple and effective method for patterning of highly aligned nanowires using a microcontact printing technique is demonstrated. In this method, nanowires are first directionally aligned by contact printing, following which line and space micropatterns of nanowire arrays are accomplished by microcontact printing with a micro patterned NOA mold.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.33 no.5
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• pp.355-359
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• 2020

In this study, image analysis and surface roughness measurements using an optical microscope are presented as a method to quantitatively evaluate the results of screen printing. Using this method, the squeegee speed, which is the printing process condition, and the printability of the electrode according to the screen mesh were evaluated. Increasing the squeegee speed in the printing process acts as a process element that increases the line width precision of the printed electrode and lowers the surface roughness of the printed surface. Furthermore, the edge roughness, which indicates the clarity of printing, was not significantly affected by the speed of the squeegee during printing. The print thickness increases in proportion to the squeegee speed, but is largely dependent on the screen thickness.

• Journal of the Korean Graphic Arts Communication Society
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• v.30 no.3
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• pp.45-56
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• 2012

Printing technology is accepted by appropriate technology that smart phones, tablet PC, display(LCD, OLED, etc.) precision recently in the electronics industry, the market grows, this process in the ongoing efforts to improve competitiveness through the development of innovative technologies. So printed electronics appeared by new concept. This technology development is applied on electronic components and circuits for the simplification of the production process and reduce processing costs. Low-temperature process making possible for widening, slimmer, lighter, and more flexible, plastic substrates, such as(flexible) easily by forming a thin film on a substrate has been studied. In the past, the formation of the electrode used a screen printing method. But the screen printing method is formation of fine patterns, high-speed printing, mass production is difficult. The roll-to-roll printing method as an alternative to screen printing to produce electronic devices by printing techniques that were used traditionally in the latest technology and processing techniques applied to precision control are very economical to implement fine-line printing equipment has been evaluated as. In order to function as electronic devices, especially the dozens of existing micro-level of non-dot print fine line printing is required, the line should not break at all, because according to the specifications required to fit the ink transfer conditions should be established. In this study of roll-to-roll printing conductive paste suitable for gravure offset printing by developing Ag paste for forming fine patterns to study the basic physical properties with the aim of this study were to.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.06a
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• pp.149-150
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• 2008

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1118-1121
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• 2009

We have fabricated inverted staggered pentacene Thin Film Transistor (TFT) with 1-${\mu}m$ channel length by micro contact printing (${\mu}$-CP) method. Patterning of micro-scale source/drain electrodes without etching was successfully achieved using silver nano particle ink, Polydimethylsiloxane (PDMS) stamp and FC-150 flip chip aligner-bonder. Sheet resistance of the printed Ag nano particle films were effectively reduced by two step annealing at $180^{\circ}C$.

• Laser Solutions
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• v.16 no.4
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• pp.12-16
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• 2013

For mass production of electronic devices, the processing of the printing roll is one of the most important key technologies for printed electronics technology. A roll of printing process, the gravure printing that is used to print the electronic device is most often used. The indirect laser processing has been used in order to produce printing roll for gravure printing. It consists of the following processing that is coating of photo polymer or black lacquer on the surface of printing roll, pattering using a laser beam and etching process. In this study, we have carried out study on the coating and etching for $25{\mu}m$ line width on the printing roll. To do this goals, a $4{\mu}m$ coating thickness and 20% average coating thickness of the coating homogeneity of variance is performed. The factors to determine the thickness and homogeneity are a viscosity of coating solution, the liquid injection, the number of injection, feed rate, rotational speed, and the like. After the laser patterning, a line width of $25{\mu}m$ or less was confirmed to be processed through etching and the chromium plating process.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.5
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• pp.374-380
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• 2011

In this paper a printing process for patterning electrodes on large area substrate was developed by combining screen printing with reverse off-set printing. Ag ink was uniformly coated by screen printing. And then etching resist (ER) was patterned in the Ag film by reverse off-set printing, and then the non-desired Ag film was etched off by etchant. Finally, the ER was stripped-off to obtain the final Ag patterns. We extracted the suitable conditions of reverse Using the process we successfully fabricated gate electrodes and scan bus lines of OTFT-backplane used for e-paper, in which the diagonal size was 6 inch, the resolution $320{\times}240$, the minimum line width 30 um, and sheet resistance 1 ${\Omega}/{\Box}$.