• Journal of the Korean Vacuum Society
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• v.18 no.4
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• pp.310-317
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• 2009

Vertical wet equipment for the BGA develop process was newly developed substituted for conventional horizontal wet equipment. The benefits of vertical equipment are that the pattern damages generated by the collision between the patterns and transferring rollers can be eliminated because the direct contact between the equipment's transferring units and the soft dry film patterns does not occurs. Taguchi experiment was conducted to optimize the process characteristics for the vertical equipment. The experiment was organized as the smaller the better problem which includes adequate uncontrollable factor and controllable factors. The uncontrollable factors are the 4 sides of two panels which are loaded to the equipment at the same time. By the analysis of the experiment, temperature of the develop chemicals and develop spraying time are analyzed as the main controllable factors. Finally, line pattern's minimum width which is not damaged for the develop process was improved from $13.8{\mu}m$ for the horizontal equipment to $10.4{\mu}m$ for the vertical equipment. And dot pattern's minimum width is improved from $22.1{\mu}m$ to $16.3{\mu}m$.

• Journal of the Korean Graphic Arts Communication Society
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• v.3 no.1
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• pp.1-10
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• 1985

In Graphic art reproduction process it is important to realize that which set of inks and their densities (film thickness) and which set of halftone positive should be aimed at. in order to meet the demand for good color reproduction. There have been various studies to calculation the color reproduction of the graphic arts. however. these study were based on the assumed characteristics of the materials. In this study the relationship between wet-trapping (wet on wet-printing) and increases of ink layer and printing sequence are examined.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.667-667
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• 2013

Optimizing morphology of the front surface with three dimensional structures (3D) in solar cell is essential element for not only effectivelight harvesting but also carrier collection and separation without the cost burden in process. We designed a three-dimensionally ordered front surface with wet chemical etching. Wet chemical etching is a proper way to have three dimensional structures. The method efficiently transmits the incident light at the front surface to a Si absorber and has competitive price in manufacturing when comparing with reactive ion etching (RIE) to have three dimensional structures. This indicates that optimized front surface with three dimensional structures by wet chemical etching will bring effective light management in solar cells.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.935-938
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• 1997

Recently, the minimum line width shows a tendency to decrease and the multi-level increase in semiconductor. Therefore, a planarization technique is needed and chemical mechanical polishing(CMP) is considered as one of the most suitable process. CMP accomplishes a high polishing performance and a global planarization of high quality. But there are several defects in CMP such as micro-scratches, abrasive contaminations, and non-uniformity of polished wafer edges. Wet etching include of Spin-etching can improve he defects of CMP. It uses abrasive-free chemical solution instead of slurry. On this study, ILD(INterlayer-Dielectric) was removed by CMP and wet-etching methods in order to investigate the superiority of wet etching mechanism. In the thin film wafer, the results were evaluated at a viewpoint of material removal rate(MRR) and within wafer non-uniformity(WIWNU). And pattern step height was also compared for planarization characteristics of the patterned wafer.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.889-892
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• 2009

We have developed a practical printing technology for the gate electrode of organic thin film transistors(OTFTs) by combining screen-printing with wet-etching process using nano-silver ink as a conducting material. The screen-printed and wet-etched Ag electrode exhibited a minimum line width of ~5 um, the thickness of ~65 nm, and a resistivity of ${\sim}10^{-6}{\Omega}{\cdot}cm$, producing good geometrical and electrical characteristics for gate electrode. The OTFTs with the screen-printed and wet-etched Ag electrode produced the saturation mobility of $0.13cm^2$/Vs and current on/off ratio of $1.79{\times}10^6$, being comparable to those of OTFT with the thermally evaporated Al gate electrode.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.683-686
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• 2009

We report inverted white OLEDs fabricated by full wet processes. We utilized inverted structure OLEDs since the structure was better for the realization of full wet fabrication of OLEDs. It was found that the performance of inverted OLEDs is comparable to that of conventional OLEDs. In this presentation, we will discuss in detail a few important issues on the full wet fabrication of OLEDs.

• Journal of the Korean Ceramic Society
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• v.27 no.6
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• pp.755-762
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• 1990

The tungsten paste was printed on the surface of 92% alumina sheet which was made by type casting process. The printed tungsten was bonded on the Al2O3 by co-firing in reducing atmosphere. During the co-firing, the binder burn-out was easier in wet H2 atmosphere than in dry H2, which affected sintered density. In practically, the use of wet H2 above 100$0^{\circ}C$ was beneficial for density of alumina and bond strength. This phenomena occured more distinctly when atmosphere varied from dry H2 to wet H2 than varied dew point in wet H2. In wet H2, the improvement in bonding strength can be attributed to good glass migration into the metal layer due to inhibition of the tungsten particle growth, with increase of alumina density, at the temperatrue higher than 100$0^{\circ}C$.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.533-534
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• 2010

• Proceedings of the IEEK Conference
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• 2003.07b
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• pp.783-786
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• 2003

A simple fabrication method of self-aligned ridge waveguides with dielectric side buffers is demonstrated on +Z- cut LiNbO$_3$. The ridge waveguide is fabricated by a combination of the annealed proton exchange process and the proton-exchanged wet etching technique. The self-aligned process is achieved by wet etching of aluminum.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.10a
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• pp.755-756
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• 2009