• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.311-312
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• 2007

In this study, composite $BaSrTiO_3$ has been studied for high frequency device applications. Composite $Ba_{0.5}Sr_{0.5}TiO_3$ has high dielectric permittivity and low loss tangent at the relative frequency range from MHz to GHz. 10,30 and 50 wt% of epoxy doped $Ba_{0.5}Sr_{0.5}TiO_3$ powders were prepared with bisphenol A and F polymer employing ball milling process. Epoxy/($BaSrTiO_3$) composites thick films were screen printed on the Cu plated PCB substrates through screen printing methods. The specimens were designed for the embedded capacitor applications. Temperature dependent dielectric permittivity of Epoxy doped $BaSrTiO_3$ ceramics was measured.

• Transactions on Electrical and Electronic Materials
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• 제12권6호
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• pp.271-274
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• 2011

Screen-printed source and drain electrodes were used for a spin-coated and inkjet-processed zinc-tin oxide (ZTO) TFTs for the first time. Source and drain were silver nanoparticles. Channel length was patterned using screen printing technology. Different silver nanoinks and process parameters were tested to find optimal source and drain contacts Relatively good electrical properties of a screen-printed inkjet-processed oxide TFT were obtained as follows; a mobility of 1.20 $cm^2$/Vs, an on-off current ratio of $10^6$, a Vth of 5.4 V and a subthreshold swing of 1.5 V/dec.

• Transactions on Electrical and Electronic Materials
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• 제7권2호
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• pp.72-75
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• 2006

Ferroelectric PZT heterolayered thick films were fabricated by the alkoxide-based sol-gel method. PZT(Zr/Ti=60/40) paste was made and alternately screen-printed on the $Al_2O_3$ substrates. We have introduced a press-treatment to obtain a good densification of screen printed films. The porosity of the thick films was decreased with increasing the applied pressure and the thick films pressed at $0.6ton/cm^2$ showed the dense microstructure and thickness of about $76{\mu}m$. The relative dielectric constant increased with increasing the applied pressure. The remanent polarization and coercive field increased with increasing applied pressure and the values for the PZT thick films pressed at $0.6ton/cm^2$ were $16.6{\mu}C/cm^2$, 76.9 kV/cm, respectively.

• Bulletin of the Korean Chemical Society
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• 제23권3호
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• pp.427-431
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• 2002

A screen printed graphite electrode has been developed for a simple and sensitive determination of phenolic compounds in an aqueous solution. The electrode developed uses a simple and effective screen printing technique with ${\alpha}-Cyclodextrin({\alpha}-CD)$ modified graphite ink. Phenols were captured on the surface of the ${\alpha}-CD$ modified electrode through complex formation. The phenol/ ${\alpha}-CD$ complex was deposited and quantified electrochemically using cyclic voltammetry (CV), differential pulse voltammetry (DPV) and square wave voltammetry (SWV). The optimization of the experimental parameters was performed in regard to electrode composition, pH, temperature, sample preconcentration time. Interferences from other organic compounds were investigated. The detection limit for phenols was 500 ${\pm}7$ nM for DPV, with the linear range of 0.5 ${\mu}M$ -25.0 ${\mu}M$ and 30 ${\pm}2$ nM for SWV, with the linear range of 30 nM - $50{\mu}M$, respectively.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.917-919
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• 2009

Effects of nano-silver contents(15~50wt%) on screen printed-etched gate electrodes and electrical characteristics of OTFTs were investigated. As Ag contents increased, the screen-printed film was transferred exactly without spreading and obtained the densely-packed layer with a stable and excellent conductivity but, its thickness was increased and surface became rougher. It was found that the leakage current of MIM devices and off-state currents of OTFTs became larger due to poor step coverage of PVP dielectric layer on the thick and rough gate electrodes for nano-Ag inks with Ag contents more than 30wt%.

• Bulletin of the Korean Chemical Society
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• 제30권8호
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• pp.1881-1883
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• 2009

• 한국정밀공학회지
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• 제27권9호
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• pp.20-25
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• 2010

The effect of micro surface structure on printing for printed electronics has been studied experimentally. The photolithography MEMS fabricationwass used to make a SU-8 molder which has micro structures on the surface, and the PDMS micro structure was fabricated by the PDMS molding method. In the aspect of printed electronics, we used silver paste conductive ink. We measured the surface energy variation on pillar microstructure. The microstructure was used to real printing experiment by a screen printing. We printed 1cm micro lines which have $30{\sim}250{\mu}m$ width, and checked the conductivity to sort out opened line pattern. Printability was defined by success probability of printed patterns and we found that the present microstructures improve the printability significantly.

• International Journal of Precision Engineering and Manufacturing
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• 제4권4호
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• pp.51-56
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• 2003

Generally, the build-up printed circuit board manufactured by a sequential process involving etching, plating, drilling, etc, which requires many types of equipments and long lead time. Etching process is suitable for mass production, however, it is not adequate for manufacturing a prototype in the development stage. In this study, we introduce a screen printing technology for prototyping a build-up printed circuit board. As for the material, photo/thermal curable resin and conductive paste are used for the formation of dielectric and conductor. The build-up structure is made by subsequent processes such as formation of a liquid resin thin layer, solidification by a UV/IR light, and via hole filling with a conductive paste. By use of photo curable resin, productivity is greatly enhanced compared with thermal curable resin. Finally, the basic concept and the possibility of build-up printed circuit board prototyping are proposed in comparison with the conventional process.

• 마이크로전자및패키징학회지
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• 제24권3호
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• pp.71-76
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• 2017

열 소결 공정 중 소결 온도와 시간을 다르게 하여 제작된 은 인쇄회로의 전기적 거동과 유연성을 분석하였다. 은 인쇄회로의 비저항값과 고주파 전송 특성을 4-포인트 프로브 및 네트워크 분석기를 사용하여 각각 측정하였다. 비저항값은 DC 전류가 회로에 흐를 때의 전기 저항을, 고주파 전송 특성은 은 회로의 신호 전송 특성을 의미한다. 은 인쇄회로의 유연성은 IPC 슬라이딩 테스트 중 발생하는 회로 저항의 변화를 실시간으로 측정하여 평가하였다. 은 인쇄회로의 파괴 모드는 주사전자 현미경과 광학 현미경을 통해 관측하였다. 폴리이미드 기판 위에 인쇄된 은 회로의 비저항값은 소결 온도와 소결 시간이 증가함에 따라 급격하게 감소하였다. $250^{\circ}C$에서 45분간 열 소결된 은 인쇄회로의 비저항값이 가장 낮았으며 그 때의 값은 $3.8{\mu}{\Omega}{\cdot}cm$였다. 은 인쇄회로에서 발생한 균열은 슬라이딩 테스트 10만번 이후의 길이가 2.5만번 테스트 후의 균열보다 열 배는 더 길게 측정되었다. 측정된 전송계수와 반사계수는 전산모사 결과와 그 경향이 거의 일치하였으며 슬라이딩 테스트가 진행될수록 은 회로의 전송손실은 증가하였다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.111-113
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• 2009

This paper shows that you can achieve high quality N+ emitter layers using a screen printable phosphorous diffusion paste and firing in an infrared belt furnace. Spreading resistance measurement from a beveled sample is used to measure carrier concentration as a function of depth for different phosphorous concentrations. Contours of estimated sheet resistance are shown for different processing conditions. This paper describes newly developed low cost phosphorous pastes. It shows the characterization of the newly developed phosphorous paste (DP99-038). This low cost pastes can easily be printed and make 16% efficiency.