• Journal of the Korean Ceramic Society
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• v.46 no.1
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• pp.41-46
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• 2009

The rheological properties of highly concentrated Ag nano sol depending on particle size were studied. The Ag nano sol was prepared by reducing the Ag ion in aqueous solution. The size of Ag nano particle was controlled by two steps of nucleation and growth, and the thickness of adsorption layer was varied by molecular weight of polyelectrolytes. The polyelectrolytes acted as not only ionic complex agent in ionic state and but also dispersant after formation of Ag nano sol. The effective volume was controlled by combination of varying the molecular weight of polyelectrolytes and the size Ag nano sol. The particle size and the viscosity of nano sol were characterized by particle size analyzer, HR-TEM and cone & plate viscometer. It was found that the 10 nm and 40 nm-sized Ag nano sols were prepared by controlling the nucleation and growth steps, respectively. Finally, we could prepare highly concentrated Ag nano sol over 50 wt%.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.799-802
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• 2008

The metal films ink-jetted using the conductive ink based on a mixture of copper and silver nanoparticles were investigated. The porosity and resistivity of films were minimized by adjusting the mixing ratio of Cu and Ag nanoparticles. We demonstrated that the printed tracks with good conductivity could be obtained at sufficiently lower annealing temperatures where plastic substrates could be used.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1450-1451
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• 2008

To investigate the reliability of the conductive lines patterned by ink-jet printing, we evaluated the reliability of the ink-jet printed silver (Ag) patterns according to the guide lines built up as assessments methods in the production of conventional rigid printed circuit boards. The assessment methods include the uniformity of line width and space, adhesive strength, dielectric withstand, solder float, thermal shock test and pressure cooker test (PCT). To prepare assesment vehicles, different regular test patterns were created by Ag ink-jet printing on the same polyimide substrate for each of assessment methods.

• Proceedings of the Materials Research Society of Korea Conference
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• 2007.11a
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• pp.89.2-89.2
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• 2007

• Journal of Sensor Science and Technology
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• v.33 no.1
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• pp.24-29
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• 2024

Inkjet printing technology is used to mass-produce displays and electrochemical sensors by dropping tens of pico-liters or less of specific-purpose ink through nozzles, just as ink is sprayed and printed on paper. Unlike the deposition method for vaporizing material in a vacuum, inkjet printing technology can be used for processing even under general atmospheric pressure and has a cost advantage because the material is dissolved in a solvent and used in the form of ink. In addition, because it can only be printed on the desired part, masks are not required. However, a technical shortcoming is the difficulty for commercialization, such as uniformity for forming the thickness and coffee ring effect. As sizes of devices decrease, the need to print electrodes with precision, thinness, and uniformity increases. In this study, we improved the printing and processing conditions to form a homogeneous electrode using Ag ink (DGP-45LT-15C) and applied this for patterning to fabricate a heat sensor. Upon the application of voltage to the heat sensor, the model with an extended width exhibited superior heat performance. However, in terms of sheet resistance, the model yielded an equivalent value of 21.6 Ω/□ compared to the ITO.

• 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 the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.6
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• pp.462-467
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• 2013

In this paper, we analyzed the effects of doctoring process on the patterns of Ag ink in gravure off-set printing. The parameters of doctoring process were the angle and the pressure, which was represented by the depth of blade movement to the gravure roll, of doctor blade to the surface of gravure roll, and the angle of patterns engraved on the gravure roll to the doctor blade moving direction. The proper parameters were extracted for the fine patterns and they were 15 mm for the pressure, $60^{\circ}$ for the blade angle. And the angle of patterns with respect to the blade movement should be less than $40^{\circ}$ for the best results. The gravure off-set printing with the above parameters was carried out to print gate electrodes and scan bus lines of OTFT-backplane for e-paper. The line width of $50{\mu}m$ was successfully obtained. The thickness of electrodes was $2.5{\mu}m$ and the surface roughness was $0.65{\mu}m$ and the sheet resistance was $15.8{\Omega}/{\Box}$.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.910-913
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• 2009

This paper examines attaching speed, detaching speed and contact time which affected in the ink transfer ratio and presents the best conditions for fabrication process of electrodes with Ag-ink using microcontact printing method. In conclusion, it shows the best printing characteristic by two conditions. One of condition is the attaching speed have to within less than 1mm/s and the detaching speed is high velocity as 1000mm/s and the contact time is taken about the minimum time when inking process. Another condition is the attaching speed have to within more than 100mm/s and the detaching speed have to within less than 1mm/s and the contact time is longer than 30second when the printing process. As using these condition and the stamp sized 5cm${\times}$5cm, it was possible for printing equally until $30{\mu}m$ of width. The printed thickness of a electrode was about 300 to 500 nm, the surface roughness was about dozens nm under 50 nm.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.36 no.5
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• pp.494-499
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• 2023

In this paper, in order to apply the CF (color filter) type of the micro light emitting device (Micro LED) display method, a study on the manufacturing process of red and green phosphor inks for the inkjet process was conducted. The blue light-emitting KSF and LuAG phosphors were respectively used to control the phosphor particle size to about 1㎛, and a phosphor ink was prepared by synthesizing with a low-viscosity solution (IPA/Eg). A chemical dispersion method was applied to selectively control the dispersion characteristics in the manufacture of phosphor inks, and in particular, phosphor inks with a dispersant applied a dispersant secured stable dispersion characteristic compared to phosphor inks without a dispersion process. Therefore, it seems possible to manufacture CF for Micro LED through an inkjet process capable of controlling the dispersion characteristics of phosphor ink.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.559-560
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• 2006

Inkjet Printing is very attractive method for direct patterns with no masks, In order to Achieve direct printing with nano metal, It is often necessary to print them with highly concentrated Ink We research the High Concentrated silver nano ink. Formulation which has a good thermal stability and storage stability and jet stability using a ethylene glycol ether. Normally Alcohol-based inks can be sensitive But High boiling point ethylene glycol ether base Ink is creating a stable meniscus and minimum maintenance issues. We are reaching a 50~60wt% high Silver Ink using a Hydrophilic Ag Nano powder. (30~50nm)