• Applied Chemistry for Engineering
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• v.20 no.2
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• pp.172-176
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• 2009

In this research, we defined the basic structure of soft etching material as $H_2SO_4/H_2O_2$, and used additives as inhibitor, surfactant, and stabilizer. By analyzing influence to surface roughness and change of etching rate related to type and density of additives, we research to develop soft etching material having the same adhesiveness as existing etching material. As a result of research, it is estimated that after densities of $H_2O_2$ and $H_2SO_4$ are 3%, 4% respectively, 500 ppm of amine type 5-Azol, as inhibitor, and 600 ppm of PEI, as surfactant, and 10 ppm of phosphoric acid, as stabilizer, are added, is the most reasonable surface roughness and etching rate. As result of solder test, it is estimated that solder resist ink did not peel away or curl up and have reliable adhesiveness.

• Journal of Information Display
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• v.1 no.1
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• pp.52-58
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• 2000

We observed that static electricity has an influence on the etching unformity of dry etching process. When the static electricity was applied from-200[V]to-1000[V] on glass substrates, the etching rate uniformity was changed to 1.5%-15%. In this experiment, the soft X-ray to neutralize static electricity was adopted as ore of neutralization methods. As an experimental result, soft X-ray irradiation improved neutralization capability on the surface of LCD glass substrate within the short time, about 15-30sec. The difference of etching rate uniformity was below 0.5%.

• Journal of the Korean Applied Science and Technology
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• v.32 no.3
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• pp.512-521
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• 2015

In this research, environmental friendly organic acid containing microetching system to improve adhesion strength between photoresist resin and Copper Clad Laminate(CCL) was developed without using strong oxidant $H_2O_2$. Etching rate and surface contamination on CCL were examined with various etching conditions with different etchants, organic acids and additives. to develope an optimum microetching condition. Etching solution with 0.04 M acetic acid showed the highest etching rate $0.4{\mu}m/min$. Etching solution with the higher concentration of APS showed the higher etching rate but surface contamination on CCL is very serious. In addition, stabilizer solution also played an important role to control the surface contamination. As a result of research, the etching solution containing 0.04 M of acetic acid, 0.1 M of APS with 4 g/L of stabilizer solution(ST-1) was best to improve adhesion between CCL and photoresist resin as well as showed the most clean and rough surface with the etching rate of $0.37{\mu}m/min$.

• 한국정보디스플레이학회:학술대회논문집
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• 2000.01a
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• pp.77-78
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• 2000

We verified the charged static electricity on LCD glass influences upon the etching uniformity of dry etching process by plasma. In the TFT-LCD manufacturing process, we mainly paid attention to eliminate the static electricity for TFT reliability. The static electricity caused the serious ununiformity of etching surface profile and etching rate in the dry etch process. Through our experiment on the made static electricity from -200V to -1000V, it was confirmed that the static electricity on LCD glass caused the etching rate variation of $1.5%{\sim}15%$. We recommend the etching process equipment for LCD manufacturing have to establish the soft X-ray exposure module system for eliminating the static electricity inside the loading and unloading chamber.

• Journal of the Korean Magnetics Society
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• v.14 no.2
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• pp.59-64
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• 2004

We investigated the soft magnetic properties of nanocrystalline Fe-Al-O film as etching the oxide film with ion beam etching method. It is thought that the grain size of Fe-Al-O film increases as the thickness decreases. The coercivity and squareness increase with decreasing thickness. The surface curvature of Am images increases when the etching experiment proceeds. This phenomena could be due to the grain growth which occurs during sputtering. This grain growth could be assisted by the the plasma energy during sputtering. Therefore proper thickness should be searched to acquire the good soft magnetic properties for the nanocrystalline film material. Good soft magnetic properties of Fe-Al-O film was acquired at the thickness of more than 900 nm.

• Carbon letters
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• v.13 no.4
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• pp.205-211
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• 2012

Methanol as a carbon source in chemical vapor deposition (CVD) graphene has an advantage over methane and hydrogen in that we can avoid optimizing an etching reagent condition. Since methanol itself can easily decompose into hydrocarbon and water (an etching reagent) at high temperatures [1], the pressure and the temperature of methanol are the only parameters we have to handle. In this study, synthetic conditions for highly crystalline and large area graphene have been optimized by adjusting pressure and temperature; the effect of each parameter was analyzed systematically by Raman, scanning electron microscope, transmission electron microscope, atomic force microscope, four-point-probe measurement, and UV-Vis. Defect density of graphene, represented by D/G ratio in Raman, decreased with increasing temperature and decreasing pressure; it negatively affected electrical conductivity. From our process and various analyses, methanol CVD growth for graphene has been found to be a safe, cheap, easy, and simple method to produce high quality, large area, and continuous graphene films.

• Corrosion Science and Technology
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• v.8 no.3
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• pp.93-102
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• 2009

The direct-current electroetching of high purity aluminum in hot aqueous-chloride solution produces a high density of micrometer-wide tunnels whose walls are made up of the {100} planes and penetrate aluminum in the <100> directions at rates of micrometer per second. In the process of the alternating-current pitting of aluminum, cathodic polarization plays an important role in the nucleation and growth of the pits during the subsequent polarization. The direct-current tunnel etching and alternating-current etching of aluminum are basically related to the formation of poorly crystallized or amorphous passive films. If the passive film forms on the wall, a natural misfit exists between the film and the aluminum substrate, which in turn gives rise to stress in both the film and the substrate. Even though the amorphous films do not have directed properties, their stresses are influenced by the substrate orientation. The films on elastically soft substrate are likely to be less stressed and more stable than those on elastically hard substrate. The hardest and softest planes of aluminum are the {111} and {100} planes, respectively. Therefore, the films on the {111} substrates are most likely to be attacked, and those on the {100} substrates are least likely to be attacked. For the tunnel etching, it follows that the tunnel walls tend to consist of the {100} planes. Meanwhile, the tunnel tip, where active corrosion takes place, tend to be made of four closely packed {111} planes in order to minimize the surface energy, which gives rise to the <100> tunnel etching.

• Proceedings of the Materials Research Society of Korea Conference
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• 2005.05a
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• pp.112-112
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• 2005

• Membrane Journal
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• v.13 no.1
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• pp.9-19
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• 2003

Membrane process was investigated to recover process water and valuable gold from washing water of electroless PCB plating processes. The filtration experiments were carried out using not only a RO membrane test cell to determine suitable membrane for washing water but also spiral wound membrane modules of nanofiltration and reverse osmosis for scale-up. At first, RO-TL(tap water, low pressure), RO-BL(brackish water, low pressure) and RO-normal(for water purifier) sheet membranes made by Saehan Co. were tested, and the performance of RO-TL membrane showed most suitable f3r recovery of soft etching, catalyst and Ni washing waters. As a result of RO test cell, the experiments for scale-up were carried out using RO-TL modules far water purifier at 7bar and $25^{\circ}C $The permeate flux fur Au washing water was about 30 LMH, but Au rejection was less than 80%. The permeate fluxes for Pd, Ni and soft etching washing water were about 22, 17 and 10 LMH, respectively. The Pd, Ni and Cu rejections showed more than 85, 97 and 98% respectively. The nanofiltration module for water purifier was introduced to recover Au selectively from Au, Ni and Cu ions in Au washing water. Most of Ni and Cu ions in the feed washing water were removed, and only Au ion was existed 81.9% in the permeate. Furthermore, Au ion in the permeate was concentrated and recovered by RO-TL membrane module. Finally, Au was also able to recover effectively by using 4 inch diameter spiral wound modules of NF and RO-TL membranes, in series.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.7 s.184
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• pp.138-145
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• 2006

A nanopatterning technique was proposed and demonstrated for low cost and mass productive process using the scanning probe lithography (SPL) and soft lithography. The nanometer scale structure is fabricated by the localized generation of oxide patterning on the H-passivated (100) silicon wafer, and soft lithography was performed to replicate of nanometer scale structures. Both height and width of the silicon oxidation is linear with the applied voltagein SPL, but the growth of width is more sensitive than that of height. The structure below 100 nm was fabricated using HF treatment. To overcome the structure height limitation, aqueous KOH orientation-dependent etching was performed on the H-passivated (100) silicon wafer. Soft lithography is also performed for the master replication process. Elastomeric stamp is fabricated by the replica molding technique with ultrasonic vibration. We showed that the elastomeric stamp with the depth of 60 nm and the width of 428 nm was acquired using the original master by SPL process.