• Journal of the Korean institute of surface engineering
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• v.41 no.3
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• pp.102-108
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• 2008

In this paper, the LiF and polymer thin film as passivation layer have been evaporated on green OLED devices. HDPE, polyacenaphthylene, polytetrafluoroethylene, poly(2,6-dimethyl-1,4-pheneylene oxide), poly sulfone and poly(dimer-acid-co-alkyl poly-amine) have been used as polymer materials. The optical transmittance of evaporated polymer thin film was very good as an above 90% in visible range. The morphology of polymer thin film was measured by AFM. As a result of the measurement average roughness($R_a$) value of the polysulfone was very low as 2.2 nm. The green OLED devices with a structure of ITO/HIL/HTL/EML/Buffer/Al in series of various passivation films were fabricated and analyzed. It was observed that an OLED device with LiF as first passivation film has shown the good electrical and optical property, and all kind of polymer films did not influence on the I-V-L characteristics and the life time of OLED devices. Therefore, we found that polymer layer played a key role as a buffer layer between the inorganic passivation layers to relieve the stress of the inorganic layers.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.48 no.2
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• pp.56-60
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• 2016

Neutral or alkaline papermaking provides many advantages in paper strength and processing conditions. It also provides the opportunity of using calcium carbonate fillers in papermaking. These diverse advantages have made almost all paper machines of printing and writing papers run under neutral and alkaline conditions. On the other hand, linerboard machines, which use recycled papers as a raw material, are running under acid conditions using a rosin sizing system. Because the recycled raw materials used by the linerboard industry contain significant amounts of alkaline papers, the linerboard industry has an interest in the possibility of using the neutral or alkaline papermaking opportunity. In this study, the compatibility of the recycled linerboards under neutral or alkaline papermaking conditions was examined by recycling them under various pH conditions. The sizing degree of the papers recycled under neutral or alkaline was significantly lower than that of acid formed papers indicating that during the neutral or alkaline recycling process the rosin sized papers lost their sizing efficiency. Recycling of acid formed linerboards under neutral or alkaline conditions increased the amount of foam, and the foam contained substantial amount of solid materials derived from the acid sizing systems. Use of cationic polyelectrolytes including PEI and poly-DADMAC improved the sizing degree of the recycled papers under neutral and alkaline conditions. PEI decreased the foam generation as well while poly-DADMAC did not show any reducing effect of the foam. These results suggest that PEI forms coordinate bonds with rosin acid and precipitate them onto the surface of recycled fibers, while the reaction products between poly-DADMAC and rosin acid ions still remain water soluble under neutral or alkaline conditions.

• Polymer(Korea)
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• v.37 no.6
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• pp.730-735
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• 2013

The physical properties of poly(vinyl alcohol) (PVA) with polyamide-epichlorohydrin (PAE) for wet strength additives in paper industry were investigated. Upon introducing PAE to PVA, not only melting and crystallization enthalpy in DSC but also the area of diffraction peaks in XRD decreased, which represented the fact that PAE acted as a crosslinking agent for PVA. However, this crosslinking seemed to be physical crosslinking having relatively less bonding energy compared to chemical crosslinking since the crystallization in PVA was able to take place by thermal annealing. This physical crosslinking and crystallization by thermal annealing enhanced the thermal stability and mechanical strength in PVA and consequently, these improvements are desired in the paper manufacturing process to increase the dry and wet strength in the paper.

• Journal of the Microelectronics and Packaging Society
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• v.15 no.4
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• pp.59-64
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• 2008

In this paper, white polymer light emitting diodes(WPLEDs) were fabricated and investigated the electrical and optical properties for the prepared devices. ITO(indium tin oxide) and PEDOT:PSS [poly(3,4-ethylenedioxythiophene):poly(styrene sulfolnate)] as anode and hole injection materials, PFO [poly(9,9-dioctylfluorene)] and MEH-PPV [poly(2-methoxy-5(2-ethylhe xoxy)-1,4-phenylenevinyle)] were used as the light emitting host and guest materials, respectively. The LiF(lithium flouride) and Al(aluminum) were used electron injection materials and cathode materials. Finally, the WPLED with structure of ITO/PEDOT:PSS/PFO:MEH-PPV/LiF/Al was fabricated. The prepared WPLED showed white emission with CIE coordinates of (x=0.36, y=0.35) at the applied voltage of 9V. The maximum current density and luminance were about $740mA/cm^2\;and\;900cd/m^2$ at 13V, respectively. And the maximum current efficiency was 0.37 cd/A at $200cd/m^2$ in luminance.

• Journal of the Microelectronics and Packaging Society
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• v.24 no.3
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• pp.7-11
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• 2017

In this paper, we have studied the characteristics of NAND Flash memory in SONOS Poly-Si Thin Film Transistor (Poly-Si TFT) device. Source/drain junctions(S/D) of cells were not implanted and selective transistors were located in the end of cells. We found the optimum conditions of process by means of the estimation for the doping concentration of channel and source/drain of selective transistor. As the doping concentration was increased, the channel current was increased and the characteristic of erase was improved. It was believed that the improvement of erase characteristic was probably due to the higher channel potential induced by GIDL current at the abrupt junction. In the condition of process optimum, program windows of threshold voltages were about 2.5V after writing and erasing. In addition, it was obtained that the swing value of poly Si TFT and the reliability by bake were enhanced by increasing process temperature of tunnel oxide.

• Membrane Journal
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• v.20 no.4
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• pp.320-325
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• 2010

This paper was carried out to study the preparation condition and the permeation flux of reinforced poly(vinylidene fluoride) (PVDF) hollow fiber microfiltration (MF) membrane with the solvent, additive, second miscible polymer, and preparation condition used poly(vinylidene fluoride) (PVDF) such as a material with the excellent chemical stability and the milder preparation condition. The performance of the reinforced MF membrane prepared obtained the average $0.3{\mu}m$ pore size, $42kg_f/cm^2$ tensile strength, and the high water flux of 600 LMH. The change of membrane performance with various additives was considerably affected on the water flux and rejection. For hydrophilic modification of hydrophobic PVDF MF membrane, the MF membrane might be prepared with a prefer water flux and rejection by addition of hydrophilic poly(methyl methacrylate) (PMMA).

• Journal of the Korean Graphic Arts Communication Society
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• v.12 no.1
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• pp.1.2-15
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• 1994

This is the study which appear the relation between the situation of Anchor point and the qualities of lithographic prints using the uncoated paper. Anchor point were measured by microscopic photography and Kubelka-munk`s method. The situation of Anchor point increased with print density and print though, but it decreased with evenness and rub off. In case of commercial uncoated paper, the situation of Anchor point was optimized when it was 25~35% apporoximately. In preparation of samples for microscopic photography, the samples were used by the resin testing methods. This method used that the resin fixes the printed papers of sample very hard, in preparation of samples for microscopica potography a good result could be gained by this method.

• Resources Recycling
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• v.11 no.1
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• pp.37-42
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• 2002

This study was conducted in order to remove Poly vinyl chloride(PVC) from the waste plastic film mixture. The fittings of Air Table was modified to increase the separation efficiency of PVC and PE(poly ethylene). PE and PVC was successfully separated from PVC-PE film mixture with the yield of PE 90% or more and with his grade of 99% or more, using the improved Air Table. The details of the separation condition and results will be discussed in this paper. Dry separation, Waste plastic film, PVC, Air Table. The details of the separation condition and results will be discussed in this paper.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.17 no.4
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• pp.266-274
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• 2024

In this paper, we designed a low-area 32-bit PF (Poly-fuse) OTP IP, a non-volatile memory that stores data required for analog circuit trimming and calibration. Since one OTP cell is constructed using two PFs in one select transistor, a 1cell-2bit multibit PF OTP cell that can program 2bits of data is proposed. The bitcell size of the proposed 1cell-2bit PF OTP cell is 1/2 of 12.69㎛ × 3.48㎛ (=44.161㎛2), reducing the cell area by 33% compared to that of the existing PF OTP cell. In addition, in this paper, a new 1 row × 32 column cell array circuit and core circuit (WL driving circuit, BL driving circuit, BL switch circuit, and DL sense amplifier circuit) are proposed to meet the operation of the proposed multbit cell. The layout size of the 32bit OTP IP using the proposed multibit cell is 238.47㎛ × 156.52㎛ (=0.0373㎛2) is reduced by about 33% compared that of the existing 32bit PF OTP IP using a single bitcell, which is 386.87㎛ × 144.87㎛ (=0.056㎛2). The 32-bit PF OTP IP, designed with 10 years of data retention time in mind, is designed with a minimum programmed PF sensing resistance of 10.5㏀ in the detection read mode and of 5.3 ㏀ in the read mode, respectively, as a result of post-layout simulation of the test chip.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.664-667
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• 1997

For higher component density per chip, it is necessary to identify and control the semiconductor manufacturing process more stringently. Recently, neural networks have been identified as one of the most promising techniques for modeling and control of complicated processes such as plasma etching process. Since wafer states after each run using identical recipe may differ from each other, conventional neural network models utilizing input factors only cannot represent the actual state of process and equipment. In this paper, in addition to the input factors of the recipe, real-time tool data are utilized for modeling of 64M DRAM s-poly plasma etching process to reflect the actual state of process and equipment. For real-time tool data, we collect optical emission spectroscopy (OES) data. Through principal component analysis (PCA), we extract principal components from entire OES data. And then these principal components are included to input parameters of neural network model. Finally neural network model is trained using feed forward error back propagation (FFEBP) algorithm. As a results, simulation results exhibit good wafer state prediction capability after plasma etching process.