• Journal of the Korean Ceramic Society
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• v.36 no.6
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• pp.583-589
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• 1999

In the fabrication of ceramic chip couples for high frequency application such as the mobile communication equipment the formation of electrode lines and Ag diffusion were investigated with heat treatment conditions for removing organic binders. The deformation and densification of the electrode line greatly depended on the binder burnout process due to the overlapped temperature zone near 400$^{\circ}C$ of the binder dissociation and the solid phase sintering of the silver electrode. Ag ions were diffused into the glass ceramic substrate. The Ag diffusion was led by the glassy phase containing Pb ions rather than by the crystalline phase containing Ca ions. The fact suggests that the Ag diffusion could be controlled by managing the composition of the glass ceramic substrate.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.45-48
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• 2006

Effectiveness and its possibility of ELA (Excimer Laser Annealing) for advanced Si TFT system on insulator are described. Currently, extensive study is carried out to realize an advanced SoG (System on Glass) based on LTPS (Low Temperature Poly-Si) technique. By reducing further the process temperature and by improving the fabrication process of LTPS, addressing TFT circuits for FPD (Flat Panel Display) can be mounted onto a flexible plastic as well as onto a glass substrate. Functional devices on the insulating panels are developed to be formed by using ELA. Although technical issues are remained for the fabrication process, Si transistors including 3D TFT structure formed by ELA is expected as a functional Si system on insulator in the ubiquitous IT era.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.434-438
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• 2006

High-quality a-Si TFTs were fabricated on 7 inch plastic PES substrates at $130^{\circ}C$ and $100^{\circ}C$. It had been shown that the key factor for successful TFT fabrication on the relatively large plastic substrates is thorough control of total active layer's stress by means of deposition temperature reduction and single layer's intrinsic stress optimization.

• Journal of Sensor Science and Technology
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• v.16 no.3
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• pp.229-233
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• 2007

The indium tin oxide (ITO) films were deposited on CR39 substrate using DC magnetron sputtering. The ITO thin films deposited at room temperature because CR39 substrate its glass-transition temperature is $130^{\circ}C$. The ITO thin films used bottom and top electrode and for organic thin film transparent transistors (OTFTs). The ITO thin film electrodes electrical properties and optical transparency properties in the visible wavelength range (300-800 nm) strongly dependent on volume of oxygen percent. For the optimum resistivity and transparency of the ITO thin film electrode achieved with a 75 W plasma power, 10 % volume of oxygen and a 27 nm/min deposition rate. Above 85 % transparency in the visible wavelength range (300-800 nm) measured without post annealing process and a low resistivity value $9.83{\times}10^{-4}{\Omega}cm$ was measured thickness of 300 nm. All fabrication process of ITO thin films did not exceed $80^{\circ}C$.

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.2001-2003
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• 1996

In this study, Allied Signal 211 SOG was used as a sacrificial material. After researching its etching properties, we adapted it to bottom-drive micrometers. SOG was superior etch rate and roughness to them of PSG or CVD-oxide and possible to low-temperature processing. Etching properties of SOG depended on the temperature and duration of its bake and cure. SOG used in the fabrication of bottom-drive micrometers showed us usefulness as a sacrificial layer and haying a least influence on machines on it in comparison with conventional sacrificial materials.

• Progress in Superconductivity and Cryogenics
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• v.24 no.3
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• pp.24-29
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• 2022

One of the recent proposals with nuclear magnetic resonance (NMR) is a multi-bore NMR which consists of array of magnets which could present possibilities to quickly cope with pandemic virus by multiple inspection of virus samples. Low temperature superconductor (LTS) can be a candidate for mass production of the magnet due to its low price in fabrication as well as operation by applying the helium zero boil-off technology. However, training feature of LTS magnet still hinders the low cost operation due to multiple boil-offs during premature quenches. Thus in this paper, LTS magnet with low mechanical stress is designed targeting the "training-free" LTS magnet for mass production of magnet array for multi-bore NMR. A thorough process of an LTS magnet design is conducted, including the analyses as the followings: electromagnetics, mechanical stress, cryogenics, stability, and protection. The magnet specification was set to 4.7 T in a winding bore of 85 mm, corresponding to the MR frequency of 200 MHz. The stress level is tolerable with respect to the wire yield strength and epoxy crack where mechanical disturbance is less than the minimum quench energy.

• Journal of Aerospace System Engineering
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• v.13 no.4
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• pp.18-25
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• 2019

Studies on the fabrication of UAV by using 3D printer have been actively carried out. However, research on structural load characteristics in low temperature environment is insufficient. In this study, a composite sandwich structure with ordinary orbs structure was proposed, and the load characteristics for temperature condition changes were analyzed. The ordinary orbs and honeycomb structures were fabricated by using a FDM type 3D printer. The bending load test was carried out at room temperature and low temperature condition. The low temperature condition was classified into four cases. Bending load tests were performed in a low temperature chamber to maintain the required temperature conditions. As a result of the test, it was confirmed that the proposed ordinary orbs structure had better load characteristics at low temperatures than the existing honeycomb structure.

• Macromolecular Research
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• v.12 no.4
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• pp.391-398
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• 2004

Thick-film photolithography is a new technology that combines lithography processes, such as exposure and development, with the conventional thick-film process applied to screen-printing. In this study, we developed a low-temperature cofireable silver paste applicable for thick-film processing to form fine lines using photolitho-graphic technologies. The optimum paste composition for forming fine lines was investigated. The effect of processing parameters, such as the exposing dose, had on the fine-line resolution was also investigated. As the result, we found that the type of polymer and monomer, the silver powder loading, and the amount of photoinitiator were the main factors affecting the resolution of the fine lines. The developed photoimageable silver paste was printed on a low-temperature cofireable green sheet, dried, exposed, developed in an aqueous process, laminated, and then fired. Our results demonstrate that thick-film fine lines having widths < 20 $\mu\textrm{m}$ can be obtained after cofiring.

• Journal of Powder Materials
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• v.13 no.1 s.54
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• pp.46-51
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• 2006

Through the volume change of Sn in a low-temperature phase transformation, the Sn nanopowder with high, purity, was fabricated by an economic and eco-friendly process. The fine cracks were spontaneously generated. in, Sn ingot, which was reduced to powders in the repetition of phase transformation. The Sn nanopowder with 50 run in size was obtained by the 24th repetitions of phase transformation by low-temperature and ultrasonic treatments. Also, the $SnO_2$ powder was fabricated by the oxidation of the produced Sn powder to the ingot and milled by the ultrasonic milling method. The $SnO_2$ nanopowder of 20 nm in size was fabricated after the milling for 180 h.

• Advances in nano research
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• v.2 no.1
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• pp.23-56
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• 2014

The significant growth of the Si photovoltaic industry has been so far limited due to the high cost of the Si photovoltaic system. In this regard, the most expensive factors are the intrinsic cost of silicon material and the Si solar cell fabrication processes. Conventional Si solar cells have p-n junctions inside for an efficient extraction of light-generated charge carriers. However, the p-n junction is normally formed through very expensive processes requiring very high temperature (${\sim}1000^{\circ}C$). Therefore, several systems are currently under study to form heterojunctions at low temperatures. Among them, carbon nanotube (CNT)/Si hybrid solar cells are very promising, with power conversion efficiency up to 15%. In these cells, the p-type Si layer is replaced by a semitransparent CNT film deposited at room temperature on the n-doped Si wafer, thus giving rise to an overall reduction of the total Si thickness and to the fabrication of a device with cheaper methods at low temperatures. In particular, the CNT film coating the Si wafer acts as a conductive electrode for charge carrier collection and establishes a built-in voltage for separating photocarriers. Moreover, due to the CNT film optical semitransparency, most of the incoming light is absorbed in Si; thus the efficiency of the CNT/Si device is in principle comparable to that of a conventional Si one. In this paper an overview of several factors at the basis of this device operation and of the suggested improvements to its architecture is given. In addition, still open physical/technological issues are also addressed.