• 전기학회논문지
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• 제58권6호
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• pp.1186-1193
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• 2009

Wearable ECG monitoring is regarded as one of the most essential part in the ubiquitous healthcare environment and subsequently day-life monitoring of a heart condition has been pursued especially for the elder people. However, there are many problems to accomplish this task such as; i) implementation of long-term monitoring device, ii) development of non-irritating electrode on skin and iii) stable signal acquisition. With these aims, we have focused on implementing a non-irritating electrode with an endurable monitoring device for day-life. To accomplish our tasks, we basically developed four different types of textile electrodes that are adapted by both shape and the composed material; flat or convex shape and Ag-conductive paste material or not. It turns out to be that a convex shape and Ag-paste textile electrode has the best performance in terms of both signal-to-noise ratio (SNR) and Impedance/Phase characteristics. Furthermore, ECG amplifier (35 ${\times}$ 35 mm) has developed to resolve the ECG signal and transfer the signal to desktop computing device or portable one by RF serial communication.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.591-592
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• 2006

We studied about the manufacture of the drain-source contacts for OTFTs(organic thin-film transistors) by using screen printing method. The conductive fillers used Ag and carbon black. The conductive contacts with $100{\mu}m$ of channel length were screen printed on a silicon dioxide gate dielectric layer and, the pentacene semiconductor was deposited via vacuum deposition. As a result of studying various conductive pastes, we could obtain the OTFTs which exhibited field-effect behavior over arrange of drain-source and gate voltages, similar to devices employing deposited Au contacts. By using screen-printing with conductive paste, the contacts are processed at low temperature, thereby facilitating their integration with heat sensitive substrates.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.116.1-116.1
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• 2011

Materials with a combination of high electrical conductivity and optical transparency are important components of many electronic and optoelectronic devices such as liquid crystal displays, solar cells, and light emitting diodes. In this study, to fabricate a low-resistance and high optical transparent electrode film for organic photovoltaic, the following steps were performed: the design and manufacture of an electroforming stamp mold, the fabrication of thermal roll imprinted (TRI) poly-carbonate (PC) patterned films, the manufacture of high-conductivity and low-resistance Ag paste which was filled into patterned PC film using a doctor blade process and then coated with a thin film layer of conductive polymer by a spin coating process. As a result of these imprinting processes the PC films obtained a line width of $10{\pm}0.5{\mu}m$, a channel length of $500{\pm}2{\mu}m$, and a pattern depth of $7.34{\pm}0.5{\mu}m$. After the Ag paste was used to fill part of the patterned film with conductive polymer coating, the following parameters were obtained: a sheet resistance of $9.65{\Omega}$/sq, optical transparency values were 83.69 % at a wavelength of 550 nm.

• 한국재료학회지
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• 제25권12호
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• pp.683-689
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• 2015

In this study, the properties of Ag-coated $TiO_2$ nanoparticles were observed, while varying the molar ratio of water and $Ag^+$ for the surfactant and $TiO_2$. According to the XRD results, each nanoparticle showed a distinctive diffraction pattern. The intensity of the respective peaks and the sizes of the nanoparticles increased in the order of AT1($R_1=5$)(33.3 nm), AT2($R_1=10$)(38.1 nm), AT3($R_1=20$)(45.7 nm), AT4($R_1=40$)(48.6 nm) as well as AT5($R_2=0.2$, $R_3=0.5$)(41.4 nm), AT6($R_2=0.3$, $R_3=1$)(45.1 nm), AT7($R_2=0.5$, $R_3=1.5$)(49.3 nm), AT8($R_2=0.7$, $R_3=2$)(57.2 nm), which values were consistent with the results of the UV-Vis. spectrum. The surface resistance of the conductive pastes fabricated using the prepared Ag-coated $TiO_2$ nanoparticles exhibited a range 7.0~9.0($274{\sim}328{\mu}{\Omega}/cm^2$) times that of pure silver paste(ATP)($52{\mu}{\Omega}/cm^2$).

• 한국분말재료학회지
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• 제24권5호
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• pp.395-399
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• 2017

Solder paste is widely used as a conductive adhesive in the electronics industry. In this paper, nano and microsized mixed lead-free solder powder (Sn-Ag-Cu) is used to manufacture solder paste. The purpose of this paper is to improve the storage stability using different types of solvents that are used in fabricating the solder paste. If a solvent of sole acetate is used, the nano sized solder powder and organic acid react and form a Sn-Ag-Cu malonate. These formed malonates create fatty acid soaps. The fatty acid soaps absorb the solvents and while the viscosity of the solder paste rises, the storage stability and reliability decrease. When ethylene glycol, a dihydric alcohol, is used the fatty acid soaps and ethylene glycol react, preventing the further creation of the fatty acid soaps. The prevention of gelation results in an improvement in the solder paste storage ability.

• 한국전기전자재료학회논문지
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• 제21권9호
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• pp.835-843
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• 2008

We have fabricated the source-drain electrodes for OTFTs by screen printing method and manufactured Ag pastes as conductive paste. To obtain excellent conductivity and screen-printability of Ag pastes, the dispersion characteristics of Ag pastes prepared from two types of acryl resins with different molecular structures and Ag powder treated with caprylic acid, triethanol amine and dodecane thiol as surfactant respectively were investigated. The Ag pastes containing Ag powder treated with dodecane thiol having thiol as anchor group or AA4123 with carboxyl group(COOH) of hydrophilic group as binder resin exhibited excellent dispersity. But, Ag pastes(CA-41, TA-41, DT-41) prepared from AA4123 fabricated the insulating layer since the strong interaction between surface of Ag powder and carboxyl group(COOH) of AA4123 interfered with the formation of conduction path among Ag powders. The viscosity behavior of Ag pastes exhibited shear-thinning flow in the high shear rate range and the pastes with bad dispersion characteristic demonstrated higher shear-thinning index than those with good dispersity due to the weak flocculated network structure. The output curve of OTFT device with a channel length of 107 ${\mu}m$ using screen-printed S-D electrodes from DT-30 showed good saturation behavior and no significant contact resistance. And this device exhibited a saturation mobility of $4.0{\times}10^{-3}$ $cm^2/Vs$, on/off current ratio of about $10^5$ and a threshold voltage of about 0.7 V.

• 한국재료학회지
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• 제13권9호
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• pp.555-560
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• 2003

Ag-coated Cu particles were prepared by dropping method of coating agent and were evaluated by scanning electron microscope and color difference meter. The shape of Cu particles having obvious crystal plan and edge was changed spherically according to the increase of Ag coating amount. When the Ag coating amount was 50 wt% to Cu particles, the whiteness of Ag-coated Cu particles was almost similar to that of pure Ag particles. Adding $NH_4$OH in reductant solution could increase effectively the whiteness of the Ag-coated particles. The Ag-coated particles having the highest whiteness was obtained when the content of hydrazine in reductant solution was 0.48 M.

• 전자공학회논문지A
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• 제28A권10호
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• pp.840-846
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• 1991

In case of the rapid thermal process by halogen lamps, an optical pyrometer is generally used to measure the temperature. It is, however, necessary to measure the temperature by the thermocouple when the process temperature is lower than 700$^{\circ}C$ and the correction of the temperature is required. Contact by the PdAg paste is commonly used out but in this case it is impossible to see the effect of surface states of the substrate, which is critical in the rapid thermal process. In this study, real temperature ramping speed of silicon substrates coveredwith various thin films such as SiO$_2$2, Si$_{3}N_{4}$, dopants, and conductive layers (Ti or Co) was investigated by a mechanical contact of the thermocouple. And the results were compared with the case in which the contact was made by the PdAg paste. Effect of process ambient was also studied. It was found that depending on the surface state, overshoot more than 100$^{\circ}C$ could occur. It was also found that in case of the substrate covered with conductive layers, mechanical contact might render the correct temperature.

• 한국인쇄학회지
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• 제30권3호
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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.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2015년도 추계학술대회 논문집
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• pp.151-153
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• 2015

무전해도금법을 이용하여 Ag/Ni 코팅 Cu 플레이크를 제조한 후 Ni 코팅층의 P 함량에 따른 Ag dewtting 거동에 대한 연구를 수행하였다. Ni 코팅층 내 P 함량이 낮을수록 Ni 코팅층의 결정성 및 결정화 속도가 높아지는 것을 알 수 있었으며, 이는 Ni 코팅층 위에 형성된 Ag 코팅층의 dewetting 거동에 영향을 주는 것으로 분석되었다. 또한 격자 불일치도가 높을수록 잘 발생하는 dewetting 현상은 P 함량이 높아 결정성이 떨어지는 Ni 코팅층에서 더욱 빨리 일어남을 알 수 있었다.