• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.155-158
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• 2007

Printed organic thin-film transistor(OTFT) to use as a switching device for an organic light emitting diode(OLED) were fabricated in the microcontact printing and direct printing processes at room temperature. The gate electrodes($5{\mu}m$, $10{\mu}m$, and $20{\mu}m$) of OTFT was fabricated using microcontact printing process, and source/drain electrodes ($W/L=500{\mu}m/5{\mu}m$, $500{\mu}m/10{\mu}m$, and $500{\mu}m/20{\mu}m$) was fabricated using direct printing process with hard poly(dimethylsiloxane)(h-PDMS) stamp. Printed OTFT with dielectric layer was formed using special coating system and organic semiconductor layer was ink-jet printing process. Microcontact printing and direct printing processes using h-PDMS stamp made it possible to fabricate printed OTFT with channel lengths down to $5{\mu}m$, and reduced the process by 20 steps compared with photolithography. As results of measuring he transfer characteristics and output characteristics of OTFT fabricated with the printing process, the field effect characteristic was verified.

• Journal of Drive and Control
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• v.16 no.3
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• pp.42-50
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• 2019

3D printing AM processes have advantages in complex shapes, customized fabrication and prototype development stage. However, due to various parameters based on both the machine and the material, the AM process can produce finished output after several trials and errors in the initial stage. As such, minimizing or optimizing negative factors for various parameters of the 3D printing AM process could be a solution to reduce the trial-and-error failures in the early stages of such an AM process. In addition, this can be largely solved through software simulation in the preprocessing process of 3D printing AM process. Therefore, the objective of this study was to investigate a simulation technology for the AM software, especially Ansys Inc. The metal 3D printing AM process, the AM process simulation software, and the AM process simulation processor were examined. Through this study, it will be helpful to understand 3D printing AM process and AM process simulation processor.

• Proceedings of the Materials Research Society of Korea Conference
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• 2010.05a
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• pp.19.1-19.1
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• 2010

The process of manufacturing printed electronics using printing technology is attracting attention because its process cost is lower than that of the conventional semiconductor process. This technology, which offers both a lower cost and higher productivity, can be applied in the production of organic TFT (thin film transistor), solar cell, RFID(radio frequency identification) tag, printed battery, E-paper, touch screen panel, black matrix for LCD(liquid crystal display), flexible display, and so forth. In general, in order to implement printed electronics, narrow width and gap printing, registration of multi-layer printing by several printing units, and printing accuracy of under $20\;{\mu}m$ are all required. These electronic products require high precision to the degree of tens of microns - in a large area with flexible material, and mass productivity at low cost. As such, the roll-to-roll printing process is attracting attention as a mass production system for these printed electronic devices. For the commercialization of this process, two basic electronic ink technologies, such as conductive ink and polymers, and printing equipment have to be developed. Therefore, this paper addressed basis design and test to develop fine patterning equipment employing the roll-to-roll printing equipment and electronic ink.

• Journal of the Korean Graphic Arts Communication Society
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• v.29 no.3
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• pp.77-96
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• 2011

Most of all manufacturing industries are pursuing the manufacturing process innovation through the production process automation but the printing industry still does not get out of the analog ways of the entire process compared the entire manufacturing industry. Today, many printing enterprises have the difficulties by the short for delivery, multi-item small amount printing, high quality, rise in raw material cost, drop in receiving order cost, and etc. The printing industry can get over these difficulties and issues by implementing the compact workflow line, merge with the others, automatization and networking, minimization of the repetitive operation, efficiency of the working process, optimization of the operators' value creation, minimization of cost and materials and fast make-ready. The object of this thesis establishes the experimental data and study cases applicable in the printing industry by having high labor productivity and work in line with printing industry processes through "lean printing system".

• Journal of the Semiconductor & Display Technology
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• v.12 no.1
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• pp.47-51
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• 2013

The screen printing is a process that is widely used in manufacturing process of various fields such as flexible devices, portable multimedia devices, OLED, and the solar cell. The screen printing method has been studied as a method for forming the high precision micro-pattern, making the low-cost manufacturing process and reducing cost through improvement of productivity. It is applicable to deposit and forming the pillars which are one of the core element for comprising vacuum glazing. In this paper, by using the paste of the glass frit base, the screen printing was performed. We analyzed the effect for the printing process to deposit pillar paste on the screen printing parameters by the factorial experimental design. The polynomial predicting the volume of the printed supporting pillars was drawn by using screen printing.

• Journal of the Korean Graphic Arts Communication Society
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• v.29 no.3
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• pp.133-142
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• 2011

We produce a photosensitive convex plate to research a Nickel metal relief printing plate using galvanic process. A Method for preparing DLC convex plate that is metalized on Nickel metal relief printing plate using CVD(Chemical Vapor Deposition) process and $N_2DLC$-convex plate that is DLC metalized thin film layer of $N_2$ plasma surface treatment are comprised. DLC thin film layers on Nickel surface are fragile. The results of the research indicate that the coefficient of friction on DLC metalized thin film layer is relatively low than Nickel surface and the durability of Nickel surface coated DLC metalized thin film layer is superior to Nickel surface. A relative evaluation of three form plate wetting properties using varnish liquid-drop plate indicates superior printing aptitudes for $N_2DLC$, DLC, Nichel plate order as above.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.57-60
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• 2009

The conductive coating method was used for a various industrial fields. For example, Sputtering process is using to a coat of ITO layer in LCD or OLED panel manufacture process and fabricate a base layer of substrate of an electric printing device. However, conventional coating process (beam sputtering, spin coating etc.) has a problems in the industrial manufacturing process. These processes have a very high cost and critical manufacturing environment as a vacuum process. Recently, many researchers were proposed a various printing process instead of conventional coating process. In this paper, we propose an ESD printing process in ITO coating layer and apply to fabricate a conductive coating film. Ours transparent electrode had a surface resistance of about $66{\Omega}/{\square}$ and transparent of 74% in the wavelength of 500nm. This transparent electrode manufacturing process will be applied to Roll-to-Roll process. In addition, we developed roll printing process system for the next generation flexible solar cell.

• Design & Manufacturing
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• v.16 no.3
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• pp.58-65
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• 2022

Micro-fluidic chip has been fabricated by lithography process on silicon or glass wafer, casting using PDMS, injection molding of thermoplastics or 3D printing, etc. Among these processes, 3D printing can fabricate micro-fluidic chip directly from the design without master or template for fluidic channel fabricated previously. Due to this direct printing, 3D printing provides very fast and economical method for prototyping micro-fluidic chip comparing to conventional fabrication process such as lithography, PDMS casting or injection molding. Although 3D printing is now used more extensively due to this fast and cheap process done automatically by single printing machine, there are some issues on accuracy or surface characteristics, etc. The accuracy of the shape and size of the micro-channel is limited by the resolution of the printing and printing direction or layering direction in case of SLM type of 3D printing using UV curable resin. In this study, the printing direction and thickness of each printing layer are investigated to see the effect on the size, shape and surface of the micro-channel. A set of micro-channels with different size was designed and arrayed orthogonal. Micro-fluidic chips are 3D printed in different directions to the micro-channel, orthogonal, parallel, or skewed. The shape of the cross-section of the micro-channel and the surface of the micro-channel are photographed using optical microscopy. From a series of experiments, an optimal printing direction and process conditions are investigated for 3D printing of micro-fluidic chip.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.2
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• pp.104-110
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• 2016

The process of three-dimensional (3D) printing (also known as "rapid prototyping" and "additive manufacturing") uses computer-created digital models to produce 3D objects with a desired shape by stacking materials through a layer-by-layer process. The industrial potential and feasibility of 3D printing technology were recently highlighted in President Obama's State of the Union address in 2013. Since his speech, worldwide investment in and attention toward 3D printing technology have increased explosively. In addition, a number of 3D printing technology-based start-up companies have been established and evaluated as emerging enterprises making successful business models. In this paper, successful start-up companies (domestic and overseas) based on 3D printing technology will be reviewed.

• Journal of Powder Materials
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• v.31 no.2
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• pp.137-145
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• 2024

In order to predict the process window of laser powder bed fusion (LPBF) for printing metallic components, the calculation of volumetric energy density (VED) has been widely calculated for controlling process parameters. However, because it is assumed that the process parameters contribute equally to heat input, the VED still has limitation for predicting the process window of LPBF-processed materials. In this study, an explainable machine learning (xML) approach was adopted to predict and understand the contribution of each process parameter to defect evolution in Ti alloys in the LPBF process. Various ML models were trained, and the Shapley additive explanation method was adopted to quantify the importance of each process parameter. This study can offer effective guidelines for fine-tuning process parameters to fabricate high-quality products using LPBF.