• Proceedings of the Korean Society of Laser Processing Conference
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• 2006.11a
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• pp.85-89
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• 2006

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.06a
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• pp.413-414
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• 2008

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.899-904
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• 2003

Microarrayer makes DNA chip and microarray that contain hundreds to thousands of immobilized DNA probes on surface of a microscope slide. This paper shows the development results for a printing type of microarrayer. It realizes a typical, low-cost and efficient microarrayer for generating low density microarray. The microarrayer is developed by using a robot of three-axes perpendicular type. It is composed of a computer-controlled three-axes robot and a pen tip assembly. The key component of the arrayer is the print-head containing the tips to immobilize cDNA, genomic DNA or similar biological material on glass surface. The robot is designed to automatically collect probes from two 96-well plates with up to 32 tips at the same time. To prove the performance of the developed microarrayer, the general water types of inks such as black, blue and red. The inks are distributed at proper positions of 96 well plates and the three color inks are immobilized on the slide glass under the operation procedure. As the result of the test, it can be shown that it has sufficient performance for the production of low integrated DNA chip consisted of 96 spots within 1 $cm^2$ area.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2000.10a
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• pp.39-45
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• 2000

A small camera module fabricated by including bare chip bonding methods is utilized to realize advanced mobile devices. One of the driving forces is the TOG (Tape On Glass) bonding method which reduces the packaging size of the image sensor clip. The TOG module is a new thinner and smaller image sensor module, using flip chip interconnection method with the ACP (Anisotropic Conductive Paste). The TOG production process was established by determining the optimum bonding conditions for both optical glass bonding and image sensor clip bonding lo the flexible PCB. The bonding conditions, including sufficient bonding margins, were studied. Another bonding method is the flip chip bonding method for DSP (Digital Signal Processor) chip. A new AC\ulcorner was developed to enable the short resin curing time of 10 sec. The bonding mechanism of the resin curing method was evaluated using FEM analysis. By using these flip chip bonding techniques, small camera module was realized.

• Journal of the Korean institute of surface engineering
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• v.40 no.2
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• pp.98-102
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• 2007

[ $NiCl_2$ ] and poly-L-lysine coated protein chip plates have been fabricated using a spin coating system. Water has been used as solvent and scratching effects on glass slides and ITO have been investigated. We also observed the surface properties of $NiCl_2$ and poly-L-lysine coated slides by using PSA(Particle size analyzer) and AFM(Atomic force microscope). The AFM results imply that the surface patterns created in the spin coating system determine the protein adsorption. Adsorption of histidine-tagged KRS proteins immobilized on glass slides and ITO was analyzed using a BAS image system. The results suggest that the scratching effect was increased ability of protein adsorption.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2000.11a
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• pp.39-45
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• 2000

In recent years, composite materials such as fiber reinforced plastics (FRP) have gained considerable attention in the aircraft and automobile industries due to their light weight, high modulus and specific strength. In practice, control of chip formation appears to be the most serious problem since chip formation mechanism in composite machining has significant effects on the finished surface ［1,2,3,4,5］. Current study will discuss frequency analysis based on autoregressive (AR) time series model and process characterization in orthogonal cutting of a fiber-matrix composite materials. A sparsely distributed idealized model composite material, namely a glass reinforced polyester (GFRP) was used as workpiece. Analysis method employs a force sensor and the signals from the sensor are processed using AR time series model. The experimental correlation between the different chip formation mechanisms and model coefficients are established.(omitted)

• 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.

• Journal of the Korean Society of Safety
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• v.16 no.3
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• pp.135-142
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• 2001

This study discusses frequency analysis based on the frequency spectrum and process characterization in orthogonal cutting of Fiber-matrix composite materials. A sparsely distributed idealized composite material, namely a glass reinforced polyester(GFRP) was used as workpiece The present method employs a force sensor and the signals from the sensor are processed using the fast Fourier transform(FFT) technique. The experimental correlations between the different chip formation mechanisms and power spectrum me established. Effects of fiber orientation, cutting parameters and tool geometry on the cutting mechanisms me also discussed.

• KSBB Journal
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• v.18 no.5
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• pp.429-433
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• 2003

LAL (Limulus amebocyte lysate) test to detect and quantity endotoxin is based on gellation reaction between endotoxin and LAL from a blood extract of Limulus polyphemus. The test is labor intensive requiring dedicated personnel, takes relatively long reaction time (approximately 1 hr), requires relatively large volume of samples and reagents, and its end-point detection method is rather subjective. To solve these problems, we attempted to develop a miniaturized LOC (lab-on-a-chip) prototype using PDMS and glass. Using the 62 mm (length) ${\times}$ 18 mm (width) prototype in which 2 mm (width) ${\times}$ 44.34 mm (length) ${\times}$ 100 $\mu\textrm{m}$ (depth) microfluidic channel was provided, we compared the various detection methods of gellation, turbidometric, and chromogenic assays to find the chromogenic method to be the most suitable for small volume assay. In this assay, kinetic point method was more accurate than end point method. We also found the PDMS chip thickness should be minimized to around 2 mm to allow sufficient light transmittance, which necessitated a glass slide bonding for chip rigidity. Through the miniaturization, the test time was reduced from 1 hr to less than 10 minutes, and the sample volume could be reduced from 100 ${\mu}\ell$ to 4.4 ${\mu}\ell$. In sum, this study revealed that the mini LOC could be an alternative for a semi-automated and reliable method for LAL test.

• Proceedings of the Materials Research Society of Korea Conference
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• 2012.05a
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• pp.51-51
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• 2012

There is a growing interest in innovative chemical synthesis in microreactors owing to high efficiency, selectivity, and yield. In microfluidic systems, the low-volume spatial and temporal control of reactants and products offers a novel method for chemical manipulation and product generation. Glass, silicon, poly(dimethylsiloxane) (PDMS), and plastics have been used for the fabrication of miniaturized devices. However, these materials are not the best due to either of low chemical durability or expensive fabrication costs. In our group, we have recently addressed the demand for economical resistant materials that can be used for easy fabrication of microfluidic systems with reliable durability. We have suggested the use of various specialty polymers such as silicon-based inorganic polymers and fluoropolymer, flexible polyimide (PI) films that have not been used for microfluidic devices, although they have been used for other areas. And inexpensive lithography techniques were used to fabricate Lab-on-a-Chip type of microreactors with differently devised microchannel design. These microreactors were demonstrated for various synthetic reactions: liquid, liquid-gas organic chemical reactions in heterogeneous catalytic processes, syntheses of polymer and non-trivial inorganic materials. The microreactors were inert, and withstand even harsh conditions, including hydrothermal reaction. In addition, various built-in microstructures inside the microchannels, for example Pd decorated peptide nanowires, definitely enhance the uniqueness and performance of microreactors. These user-friendly Lab-on-a-Chip devices are useful alternatives for chemist and chemical engineer to conventional chemical tools such as glass.