• Korean Journal of Materials Research
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• v.30 no.11
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• pp.627-635
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• 2020

3D printing technology is a processing technology in which 3D structures are formed by fabricating multiple 2D layers of materials based on 3D designed digital data and stacking them layer by layer. Although layers are stacked using inkjet printing to release various materials, it is still rare for research to successfully form a product as an additive manufacture of multi-materials. In this study, dispersion conditions are optimized by adding a dispersant to an acrylic monomer suitable for inkjet printing using Co₃O₄ and Al₂O₃. 3D structures having continuous composition composed of a different ceramic material are manufactured by printing using two UV curable ceramic inks whose optimization is advanced. After the heat treatment, the produced structure is checked for the formation and color of the desired crystals by comparing the crystalline analysis according to the characteristics of each part of the structure with ceramic pigments made by solid phase synthesis method.

• 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.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.583-584
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• 2006

Printing technology has begun to get into the spotlight in many ways due to the low cost effectiveness to existent semi-conductor process. It also has very useful application areas, not only paper printing but also patterning for LCD color tilter, Photovoltaic patterning, RFID antenna, OLED, and so on. In this study, an apparatus of gravure offset printing was developed for fine line width printing. The pattern was composed of $20{\mu}m$ size of continuous lines of which pitch size was $40{\mu}m$. The printed pattern shows that it is possible to make around $20{\mu}m$ line-width printing pattern. The roll-to-roll printing system for fine line-width printing based on primary experiment is presented. For testing of multi-layer printing, the system was designed to be capable of printing two different materials from each printing unit using gravure-offset printing method and have a function of alignment of two printed materials.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.12
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• pp.1015-1020
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• 2012

Resistance of the front electrode is the highest proportion of the ingredients of the series resistance in crystalline silicon solar cell. While resistance of the front electrode is decreased with larger area, it induces the optical loss, causing the conversion efficiency drop. Therefore the front electrode with high aspect ratio increasing its height and decreasing is necessary for high-efficiency solar cell in considering shadowing loss and resistance of front electrode. In this paper, we used the screen printing method to form high aspect ratio electrode by multiple printing. Screen printing is the straightforward technology to establish the electrodes in silicon solar cell fabrication. The several printed front electrodes with Ag paste on silicon wafer showed the significantly increased height and slightly widen finger. As a result, the resistance of the front electrode was decreased with multiple printing even if it slightly increased the shadowing loss. We showed the improved electrical characteristics for c-Si solar cell with repeatedly printed front electrode by 0.5%. It lays a foundation for high efficiency solar cell with high aspect ratio electrode using screen printing.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 1999.11a
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• pp.27-30
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• 1999

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1021-1024
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• 2003

In this work, we fabricated various 2D metallic and polymeric nanopatterns with the feature resolution of sub-micrometer scale by using the method of microcontact printing ($\mu$ P) based on soft lithography. Silicon masters for the micromolding were made by e-beam lithography. Composite poly(dimethylsiloxane) (PDMS) molds were composed of a thin, hard layer supported by soft PDMS layer. Finally, monodisperse metal or polymer particles could be obtained in the prepared pattern for the application of electronic devices.

• Bulletin of the Korean Chemical Society
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• v.32 no.12
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• pp.4281-4285
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• 2011

We introduced a promising patterned substrate by using a microcontact printing method that can be used for SERS immunoassays based on antigen-antibody binding. SERS spectrum of the Raman reporter with antibody, which is rhodamine 6G (R6G) adsorbed on colloidal gold nanoparticles, was observed only for the surfaces in which prostate-specific antigen (PSA) is present on the substrate that is attached to an immobilized layer of antibody on the gold nanoparticles layer of the patterned substrate. Raman mapping images clearly showed that the antibodies on the Raman reporter were successfully and selectively conjugated with the antigen on the patterned substrate. This method could be potentially extended to multi-protein detections and ultrasensitive biosensors.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.461-466
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• 2007

There has been a great interest in printing technology as a low cost and mass production method for the application of printed electronics such as printed TFT, solar cell, RFID Tag, printed battery, and so on. In this study, apparatuses of gravure-offset printing are developed for fine line-width/gap printing and examining pattern distortion occurred in gravure-offset printing process. The fine line-width/gap pattern shows that it is possible to make around 20 micro-meter line-width/gap printing patterns. Pattern distortion is modeled, and the amount and shape of the distortion are calculated by using commercial FEM code. The roll-to-roll printing system under development consists of unwinder/rewinder, two printing units, one coating unit, drying units, guiding unit, vision system, and other auxiliary devices. For multi-layer printing, the system is designed to be capable of printing two different materials.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.1.2-1.2
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• 2011

With recent advances in materials and products, materials processing experiences new challenges. More particles and polymers in material side and thinner and faster deformations in processing side. It happens in most emergying industries such as manufacturing of batteries, solar cells, multi-layer chips, displays, printed electronics, to list a few. In most cases, they are manufactured by coating or printing process, which is defined as a process in which gas is replaced by liquid on a substrate. In this sense, casting, inkjet printing, and roll-to-roll printing are all included. The printing process consists of three unit processes. As the materials used in the above mentioned applications typically contain a large amount of particles with polymers and solvents, they continuously change microstructures during preparation, flow, and even drying. However, little is known about the flow characteristics of such complex fluids and less is known about how to design and control the process. Therefore, for better control of the process and for better quality of the product, we need to understand the flow characteristics of these complex fluids under extremely fast flow environment.

• 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.