• Journal of the Korean Society of Radiology
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• v.3 no.2
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• pp.11-16
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• 2009

Mercury Iodide as good sensitivity at radiation and has an easy peculiarity that operates at low voltage for other photoconductors(a-Se, a-Si, Ge, etc) Based on this characteristic, we studied about an efficiency of the digital x-ray detector in acccordance with the thickness of photoconductor. To solve the problem that is difficult to make a large area film using PVD(Physical Vapor Deposition)method, we used a PIB(Particle In Binder)method. To make a binder paste, we used a PVB(Polyvinylbutyral) as a binder and a DGME(Diethylene Glycol Monobutyl Ether), DGMEA(Diethylene Glycol Monobutyl Ether Acetate) as a solvent. Using this binder paste, we made a polycrystal mercury iodide film that has an each thickness. To evaluate the electrical properties of this films, we measured a darkcurrent, sensitivity and SNR(Signal to Noise Ratio). Mercury iodide film of the 200um thickness has good electrical properties as a result of the measurement. From this result there is a good chance that replace the existing a-Se(Amnorphous seleinum; a-se) with the mercury iodide.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1239-1242
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• 2006

Scintillation that is grainy patterns appeared on a screen has been one of a biggest issues in a rear projection TVs. In this paper, with focusing on the average size of random particle, it was proved that the particle size of calculated speckle and the one of measured scintillation are almost the equal. This result shows speckle phenomenon is an important factor of scintillation.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1087-1090
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• 2008

This paper presents the electro-luminescence (EL) display lamp which is patterned on a curved surface by the pad printing method. The printing methods, including the gravure, screen, flexo, inkjet, and pad printing, have an advantage of one-step direct patterning. However, in general, the printing and semi-conductor process, except pad printing method, cannot be applied for patterning on a curved surface. Thus, in this paper, we used pad printing method for patterning an EL display lamp on a curved surface. The EL display lamp consists of 5 layers: Bottom electrode; Dielectric layer; Phosphor; Transparent electrode; Bus electrode. Finally, we printed EL display lamp on a dish, which has a radius of curvature 80mm. The EL display lamp was driven at AC 200V of 1kHz.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.400-403
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• 2004

The dielectric properties of $BaTiO_3/SrTiO_3$ multilayered thick films with printing times were investigated. $BaTiO_3/SrTiO_3$ thick films were deposited by Screen-printing method on alumina substrates. The obtained films were sintered at $1400^{\circ}C$ with bottom electrode(Pt) for 2hours. The structural and the dielectric properties were investigated for various printing times. The BST phase appeared in all of the $BaTiO_3/SrTiO_3$ mutilayered thick films. The $BaTiO_3/SrTiO_3$ multilayered thick film thickness, obtained by one printings, was $50{\mu}m$. The dielectric constant and dielectric loss of the $BaTiO_3/SrTiO_3$ multilayered thick film, obtained by five printings, were about 266, 0.8% at 1Mhz, respectively.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.05a
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• pp.15.2-15.2
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• 2009

Manufacturing of printed electronics using printing technology has begun to get into the hot issue in many ways due to the low cost effectiveness to existing semi-conductor process. This technology with both low cost and high productivity, can be applied in the production of organic thin film transistor (OTFT), solar cell, radio frequency identification (RFID) tag, printed battery, E-paper, touch screen panel, black matrix for liquid crystal display (LCD), flexible display, and so forth. The emerging technology to manufacture the products in mass production is roll-to-roll printing technology which is a manufacturing method by printings of multi-layered patterns composed of semi-conductive, dielectric and conductive layers. In contrary to the conventional printing machines in which printing precision is about $50~100{\mu}m$, the printing machines for printed electronics should have a precision under $30{\mu}m$. In general, in order to implement printed electronics, narrow width and gap printing, register of multi-layer printing by several printing units, and printing accuracy of under $30{\mu}m$ are all required. We developed the roll-to-roll printing equipment used for printed electronics, which is composed of un-winder, re-winder, tension measurement system, feeding units, dancer systems, guide unit, printing unit, vision system, dryer units, and various auxiliary devices. The equipment is designed based on cantilever type in which all rollers except printing ones have cantilever types, which could give more accurate machine precision as well as convenience for changing rollers and observing the process.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1065-1066
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• 2008

Printed thin-film transistors (TFTs) have received profound interests as an alternative to their silicon counterparts for use in fabricating next-Gen microelectronics by virtue of projected low manufacturing cost and certain salient features (e.g., thin and lightweight characteristics, structural flexibility, etc.) that printed TFTs bring to device architecture. The economic advantages stem from engaging low-cost printing techniques (e.g., screen printing, gravure, flexography, etc.) for deposition and patterning in place of traditionally costly high-vacuum, high-temperature photolithographic processes. To render printing TFTs possible, solution processable materials are necessary.

• Journal of the Korean Graphic Arts Communication Society
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• v.9 no.1
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• pp.45-51
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• 1991

Commercially available paper stickers, electrostatic stickers, and metal sticker generally involve process of printing on the substrate and die-cutting to peel the sticker off the release paper. Using plastisol ink and multi-layer screen printing technique, a process of non die-cutting sticker with same image on both sides was developed. It was also possible to prevent color mixing phenomena at image edge part by printing narrow lines of black ink along the borderline.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.5
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• pp.541-544
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• 2004

Multi- wall carbon nanotubes(MWNTs) were synthesized by thermal chemical vapor deposition. The paste for screen printing was composed of MWNTs, organic vehicle and glass frit. Carton nanotube paste was screen-printed on ITO(indium tin oxide) deposited soda lim을 glass, and then heat treatment was performed. Before the surface treatment, turn on field of derive was 2.6 V/$\mu\textrm{m}$. After the surface treatment, the value was changed into 1.8 V/$\mu\textrm{m}$. The anode current of the derive with 2.83 V/$\mu\textrm{m}$(turn on field) was changed 4 $\mu\textrm{A}$ into 390 $\mu\textrm{A}$ at 1,700 V. Adsorption effect of MWNTs onto phosphor of anode plate was observed by the field emission measurement and resulted in bad effects on properties of devices lifetime and emission lighting.

• Journal of the Korean Graphic Arts Communication Society
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• v.26 no.2
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• pp.45-54
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• 2008

We have manufactured a photoresist which has excellent dispersity and good applying property due to 330 cps of viscosity for environment-friendly and economical maskless screen plate making. And the photoresist applied on the screen stretched was exposed with mask by UV-LED light source so we could manufacture the photoresist which proper for the UV light source. And it was developed by air spray with $1.7\;kgf/cm^2$ of injection pressure. Because of the excellence of power and resolution of the UV-LED light sourse, the pencil hardness and solvent resistance of curing photoresist film were excellent as those of conventional photoresist film. Moreover the $100{\mu}m$-width stripe image which has sharp edges was formed. So we confirmed a possibility of dry development process by air spray method.

• 한국전기화학회:학술대회논문집
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• 2002.07a
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• pp.29-32
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• 2002