• Journal of Electrical Engineering and Technology
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• v.7 no.1
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• pp.91-96
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• 2012

We introduce an understanding of silver (Ag) inkjet overlap-printing characteristics from the viewpoints of cohesion between ink droplets and adhesion between an ink droplet and a surface. The printing characteristics were closely monitored by changing the surface energy to elucidate the effect of adhesion and cohesion on printing instability, such as droplet merging and line bulging. The surface energy of the substrate was changed through the hydrophilization of a hydrophobic fluorocarbon-coated surface. The surface energy and ink wettability of the prepared surfaces were characterized using sessile drop contact angle analysis, and printing instability was observed using an optical microscope after drop-on-demand inkjet printing with a 50% overlap in diameter of deposited singlet patterns. We found that the surface energy is not an appropriate indicator based on the experimental results of Ag ink printing on a hydrofluoric-treated silicon surface. The analytical approach using adhesion and cohesion was helpful in understanding the instability of the inkjet overlap-printing, as adhesion and cohesion represent the direct interfacial relationship between the Ag inks used and the substrate.

• Journal of the Korean Ceramic Society
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• v.41 no.10 s.269
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• pp.788-791
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• 2004

We have studied the fabrication of silver micro lines using the silver nano sol on ITO substrate by an ink-jet method. The average particles size of $10wt\%$ silver nano sol synthesized with polyelectrolytes was smaller than 10 nm. The pattern formation of silver nano sol on the substrate closely related with the contact angle of the silver nano sol. The dot shaped of silver nano sol on bare ITO substrate was formed due to the high contact angle of silver nano sol. When ITO substrates was treated with 100 ppm polyethylenimine for silver nano sol patterning, fine silver micro lines of $60{\sim}100{\mu}m$ width was fabricated by ink-jet method.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1491-1494
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• 2005

We have studied ink-jet printing method for patterning conductive line on flexible plastic substrates. Synthesized silver nano-particles of ${\sim}$20nm were used for the conductive ink and the printed patterns exhibit a smooth line whose linewidth is below 100 ${\mu}m$. This ink-jet printing technique can be applied to flexible displays and electronics.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1525_1526
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• 2009

In this paper, we have studied the bulging phenomenon of ink-jet printed silver lines. The used silver inks are DGP-40LT-15C and DGH-55HTG of Advanced Nano Product (ANP) Company. We investigated the behavior of bulging by changing the polarity of the inks, the surface energy of substrate and droplet spacing in printing. The contact angle of the polar inks increased much more sensitively than the nonpolar ink as the surface energy of the substrate increases. In the case of the nonpolar ink, the bulging phenomenon occurred seriously as the droplet spacing decreased at the constant surface energy.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1553-1555
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• 2008

Super-hydrophobic treated Polyimide film was used as a flexible substrate for developing a new method of metallization. Hydrophilic patterns were fabricated by IN irradiation through shadow mask. Patterned super-hydrophobic substrate was dipped into a bath containing silver nano ink Silver ink was only coated on hydrophilic patterned area. Metal lines of $600{\mu}m$ pitch were fabricated successfully. However, their thickness was too thin to serve as interconnection. To overcome this problem, iterative dipping was conducted. After repeating five times, the thickness of silver metal lines were increased to over than $2{\mu}$. After heat treatment of silver lines, their resistivities were reduced to order of $30{\mu}{\Omega}$-cm the similar level of values reported in other literatures. So, a new method of metallization has high potential for application of RFID antenna and flexible electronics substrates.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.623-624
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• 2013

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.06a
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• pp.951-952
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• 2008

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.11a
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• pp.549-550
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• 2007

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.889-892
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• 2009

We have developed a practical printing technology for the gate electrode of organic thin film transistors(OTFTs) by combining screen-printing with wet-etching process using nano-silver ink as a conducting material. The screen-printed and wet-etched Ag electrode exhibited a minimum line width of ~5 um, the thickness of ~65 nm, and a resistivity of ${\sim}10^{-6}{\Omega}{\cdot}cm$, producing good geometrical and electrical characteristics for gate electrode. The OTFTs with the screen-printed and wet-etched Ag electrode produced the saturation mobility of $0.13cm^2$/Vs and current on/off ratio of $1.79{\times}10^6$, being comparable to those of OTFT with the thermally evaporated Al gate electrode.

• Journal of Sensor Science and Technology
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• v.32 no.4
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• pp.252-256
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• 2023

A one-step method for nanoscale patterning of silver ionic ink on a substrate is developed using a microscale, elastic mold deformation. This method yields unique micro/nanoscale metallic structures that differ from those produced using the original molds. The linewidth of these metallic structures is significantly reduced (approximately 10 times) through the sidewall deformation of the original mold cavity on a thin liquid film, as verified by finite element analysis. The process facilitates the fabrication of various, isolated and complex micro/nanoscale metallic structures with negligible residual layers at low cost and high throughput. These structures can be utilized for various applications, including optoelectronics, wearable sensors, and metaverse-related devices. Our approach offers a promising tool for manipulation and fabrication of micro/nanoscale structures of various functional materials.