• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2009년도 추계학술대회 논문집
• /
• pp.235-236
• /
• 2009

• 대한기계학회논문집B
• /
• 제38권8호
• /
• pp.709-714
• /
• 2014

리버스 옵셋 인쇄는 인쇄전자를 위한 미세 패터닝기술 중 하나로서 수 ${\mu}m$ 이하의 선폭을 구현할 수 있다. 옵셋 인쇄의 특성상 잉크는 PDMS 재질의 블랑켓에 전사된 후 음각으로 패턴된 클리쉐에 접촉하여 불필요한 패턴을 제거하게 되는데, 이 때 블랑켓은 압력에 의하여 음각 패턴 내부로 침투하는 변형이 발생한다. 이러한 변형은 인쇄 압력에 비례하며, 과도한 인쇄 압력은 넓은 면적의 패턴을 인쇄할 때 클리쉐 패턴의 바닥에 블랑켓이 닿는 불량을 일으키게 된다. 이 논문에서는 리버스 옵셋 인쇄에서 가압변위에 따른 PDMS 블랑켓의 변형을 유한요소기법을 이용하여 모델링하고 접촉압력 대비 변형량을 예측함으로써 실제 인쇄 장비의 실험 결과와 비교하여 인쇄결함이 발생하지 않도록 하는 클리쉐의 제작조건을 제시하고자 한다.

• 한국정보통신학회논문지
• /
• 제17권2호
• /
• pp.263-272
• /
• 2013

인쇄전자는 다양한 기판에 기능적 소자를 프린팅한다. 인쇄방법은 스크린 인쇄, 플렉소그라피, 오프셋 리소그라피와 잉크젯 방식을 통해 적정한 패턴을 만든다. 인쇄기법을 응용하여 활용하기 때문에 전통적인 극소전자공학에 비하여 생산과정이 간단하고 비용 또한 저렴하다. 잉크젯 및 R2R(Roll to Roll)기술이 발전을 거듭해 왔기 때문에 디스플레이에서 태양전지의 제조까지 그 기술이 활용된다. IDTech(2010)에 의하면, 전자인쇄시장은 2010년에 10.99(억달러)에서 2020년 55.10(억달러)로 커질 것이며, 2030년에는 반도체산업의 규모보다 큰 3,000억 달러가 될 것으로 전망하고 있다. 센서, 배터리, 광전지, 메모리, 스마트카드 시장이 확대되는 등 조명에서 디스플레이까지 인쇄전자산업시장은 성장할 것이다.

• 한국재료학회지
• /
• 제22권9호
• /
• pp.476-481
• /
• 2012

Among the various roll-to-roll printing technologies such as gravure, gravure-offset, and reverse offset printing, reverse offset printing has the advantage of fine patterning, with less than 5 ${\mu}m$ line width. However, it involves complex processes, consisting of 1) the coating process, 2) the off process, 3) the patterning process, and 4) the set process of the ink. Each process demands various ink properties, including viscosity, surface tension, stickiness, and adhesion with substrate or clich$\acute{e}$; these properties are critical factors for the printing quality of fine patterning. In this study, Ag nano ink was developed for reverse offset printing and the effect of polyvinylpyrrolidone(PVP), used as a capping agent of Ag nano particles, on the printing quality was investigated. Ag nano particles with a diameter of ~60 nm were synthesized using the conventional polyol synthesis process. Ethanol and ethylene glycol monopropyl ether(EGPE) were used together as the main solvent in order to control the drying and absorption of the solvents during the printing process. The rheological behavior, especially ink adhesion and stickiness, was controlled with washing processes that have an effect on the offset process and that played a critical role in the fine patterning. The electrical and thermal behaviors were analyzed according to the content of PVP in the Ag ink. Finally, an Ag mesh pattern with a line width of 10 ${\mu}m$ was printed using reverse offset printing; this printing showed an electrical resistivity of 36 ${\mu}{\Omega}{\cdot}cm$ after sintering at $200^{\circ}C$.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2013년도 춘계학술대회 논문집
• /
• pp.163-164
• /
• 2013

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2008년도 제39회 하계학술대회
• /
• pp.1274-1274
• /
• 2008

In this report, the effect of substrate temperature on the electrical properties of ink-jet printed triisopropylsilyl (TIPS) pentacene organic thin-film transistors (OTFTs) has been investigated. The electrical properties such as mobility and on/off ratio were decreased as the substrate was heated above room temperature. The field-effect mobility of decreased from $10^{-2}cm^2/Vs$ to $10^{-5}cm^2/Vs$ and the on/off ratio decreased from $10^6$ to $10^4$ when the substrate temperature was heated from room temperature to 60$^{\circ}C$.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2008년도 추계학술대회A
• /
• pp.1144-1149
• /
• 2008

Converting technology has developed to print information for the decades. Recently, this technology (like gravure, gravure-offset) is rising as an alternative way for mass production of printed electronics such as RFID, solar cell. For the width of printing line is under 10 microns, registration error should be minimized less than several microns. Tension disturbance is main cause of registration error and this should be minimized before the substrate is transported into printing zone. With PI controller, it is possible to suppress the disturbance within 2% of operating tension. But register error appears more than 10 micron using PIcontroller considering noise. So LQG controller is needed as an alternative control method. In this paper, the comparision of PI and LQG controller in the converting machine including measured noise and tension disturbance is presented. It is shown that the LQG controller is more suitable for precision tension control in printed electronics.

• 한국재료학회:학술대회논문집
• /
• 한국재료학회 2010년도 춘계학술발표대회
• /
• pp.17.2-17.2
• /
• 2010

Printed electronics is an emerging technology to realize various microelectronic devices via a cost-effective method. Here we demonstrated a high performance of p-channel and n-channel top-gate/bottom contact polymer field-effect transistors (FETs), and applications to elementary organic complementary inverter and ring oscillator circuits by inkjet processing. We could obtained high field-effect mobility more than $0.4\;cm^2/Vs$ for both of p-channel and n-channel FETs, and successfully measured inkjet-printed polymer inverters. The performance of devices highly depends on the selection of dielectrics, printing condition and device architecture. Optimized CMOS ring oscillators with p-type and n-type polymer transistors showed as high as 50 kHz operation frequency. This research was financially supported by development of next generation RFID technology for item level applications (2008-F052-01) funded by the ministry of knowledge economy (MKE).

• 한국정밀공학회지
• /
• 제31권6호
• /
• pp.491-495
• /
• 2014

We developed a compact high-precision slot-die coating machine for thin-film deposition on a flexible substrate. For smooth and precise coating, air-bearing and linear motor system were employed to minimize velocity ripple. The gap control mechanism is specially designed to have repeatability of gap between nozzle and substrate under 1 ${\mu}m$. Due to extremely precise gap control, the machine can coat thin-films down to 50 nm with $200mm{\times}100mm$ size. A thin film of Ag nano-particle ink is coated for demonstration.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
• /
• pp.239-242
• /
• 2009

$Sr_2Si_5N_8:Eu^{2+}$, one of the most recently developed phosphors for use in white light emitting diodes, exhibits a two-peak emission. Namely, the emission band of $Sr_2Si_5N_8:Eu^{2+}$ is deconvoluted into two Gaussian peaks irrespective of the $Eu^{2+}$ concentration. We examined the two-peak emission of $Sr_2Si_5N_8:Eu^{2+}$ by analyzing the time-resolved photoluminescence spectra. We revealed that the two-peak emission was closely associated with the energy transfer taking place between $Eu^{2+}$ activators located at two different crystallographic sites in the $Sr_2Si_5N_8$ structure. The experimental results coincided well with the rate equation model involving the crystallographic information of the host.