• Journal of the Korea Academia-Industrial cooperation Society
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• 제16권10호
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• pp.7071-7077
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• 2015

In recently, the demand of cover-glass is increased because smart phone, tablet pc, and electrical device has become widely used. The display of mobile device is enlarged, so it is necessary to have a high strength against the external force such as contact or falling. In fabrication process of cover-glass, a grinding process is very important process to obtain high strength of glass. Conventional grinding process using a grinding wheel is caused such as a scratch, chipping, notch, and micro-crack on a surface. In this paper, polishing system using a abrasive film was developed for a grinding of mobile cover-glass. To evaluate structural stability of the designed system, finite element model of the polishing system is generated, and multi-body dynamic analysis of abrasive film polishing machine is proposed. As a result of the analysis, stress and displacement analysis of abrasive film polishing system are performed, and using laser displacement sensor, structural stability of abrasive film polishing system is confirmed by measuring displacement.

• The Transactions of the Korean Institute of Electrical Engineers C
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• 제55권6호
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• pp.291-296
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• 2006

In this study, the sputtered BTO film was polished by CMP process with the self-developed $BaTiO_3$- and $TiO_2$-mixed abrasives slurries (MAS), respectively. The removal rate of BTO ($BaTiO_3$) thin film using the $BaTiO_3$-mixed abrasive slurry (BTO-MAS) was higher than that using the $TiO_2$-mixed abrasives slurry ($TiO_2$-MAS) in the same concentrations. The maximum removal rate of BTO thin film was 848 nm/min with an addition of $BaTiO_3$ abrasive at the concentration of 3 wt%. The sufficient within-wafer non-uniformity (WIWNU%) below 5% was obtained in each abrsive at all concentrations. The surface morphology of polished BTO thin film was investigated by atomic force microscopy (AFM).

• Proceedings of the Korean Society of Precision Engineering Conference
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• 한국정밀공학회 2010년도 춘계학술대회 논문집
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• pp.301-302
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• 2010

• Journal of the Korean Society for Precision Engineering
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• 제14권10호
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• pp.68-74
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• 1997

The surface finishing system using the micro abrasive film was designed and manufactured to make the mirror surface of the cylindrical workpices. An experimental study of srface finishing was carried out to investigate the performance of mirror surface finishing system. The surface roughness value of stainless steel was about 0.2 .approx. 0.25 .mu. m Rmax, 0.02 .approx. 0.04 .mu. m Ra, using abrasive grain size of 12, 9 .mu. m. The surface roughness value of chrome coated workpiece was about 0.07 .approx. 0.11 .mu. m Ra using abrasive grain size 3 .mu. m. In the same condition, the chrome coated workpiece has obtained better surface roughness charateristics than the one of stainless steel.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• 제7권6호
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• pp.97-101
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• 1998

In this study, The ultra-precision finishing system is applicable to all kind of the cylnderical workpiece products fast and easy. This system was applied to chrome coated steel to investigate the characteristic of grinding; (1) 3$mu extrm{m}$ of abrasive film is not use for grinding performance. (2) Grinding condition of coated chrome steel would set up differently, in 30~12${\mu}{\textrm}{m}$, in 9~5${\mu}{\textrm}{m}$. (3) The surface roughness of chrome coated steel was about Ra 0.0009${\mu}{\textrm}{m}$ in abrasive grain size 5${\mu}{\textrm}{m}$.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 한국정밀공학회 1994년도 추계학술대회 논문집
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• pp.273-278
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• 1994

The surface finishing systems using the micro abrasive film were designed and manufactured to make the mirror surface of the cylindrical workpiece. An experimental study of surface finishing was carried out to investigate the performance of mirror surface finishing system. The surface roughness of stainless steel was about Rmax 0.2~0.25 .mu.m, Ra 0.02~0.04 .mu.m in abrasive grain size 12, 9 .mu.m. the surface roughness of chrome coated workpiece was about Rmax 0.07~ 0.11 .mu. m, Ra 0.01 in abrasive grain size 3 .mu. m. Also, to measure the mirror finishing time by mirror surface finishing system, the experiment was carried out on the chrome coated and ground roller of diameter 76mm and length 650mm. The finishing time and surface roughness were 40min and Rmax 0.1~0.13 .mu.m, Ra 0.01 .mu.m.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• 제17권3호
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• pp.272-277
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• 2004

The primary aim of this study is to investigate new semi-abrasive free slurry including acid colloidal silica and hydrogen peroxide for copper chemical-mechanical planarization (CMP). In general, slurry for copper CMP consists of colloidal silica as an abrasive, organic acid as a complex-forming agent, hydrogen peroxide as an oxidizing agent, a film forming agent, a pH control agent and several additives. We developed new semi-abrasive free slurry (SAFS) including below 0.5％ acid colloidal silica. We evaluated additives as stabilizers for hydrogen peroxide as well as accelerators in tantalum nitride CMP process. We also estimated dispersion stability and Zeta potential of the acid colloidal silica with additives. The extent of enhancement in tantalum nitride CMP was verified through anelectrochemical test. This approach may be useful for the application of single and first step copper CMP slurry with one package system.

• Journal of the Korean Society for Precision Engineering
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• 제18권10호
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• pp.178-183
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• 2001

Abrasive jet machining(AJM) process is similar to the sand blasting and effectively removes hard and brittle materials. AJM has applied to rough working such as debarring and rough finishing. As the need for machining of ceramics, semiconductor, electronic devices and LCD are increasing, micro AJM is developed, and has become the inevitable technique to micromachining. This paper describes the performance of the micro AJM in micro grooving of glass. Diameter of hole and width of line in grooving is 80${\mu}{\textrm}{m}$. Experimental results showed good performance in micro grooving of glass, but the size of machined groove increased about 2~4${\mu}{\textrm}{m}$. With the fine tuning of masking process and compensation of film wear. this micro AJM could be effectively applied to the micro machining of semiconductor, electronic devices and LCD.

• Journal of the Semiconductor & Display Technology
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• 제3권1호
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• pp.15-20
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• 2004

Through shallow trench isolation (STI) chemical mechanical polishing (CMP) tests, we investigated the dependence of pad surface temperature on the abrasive and additive concentrations in ceria slurry under varying pressure using blanket film wafers. The pad surface temperature after CMP increased with the abrasive concentration and decreased with the additive concentration in slurries for the constant down pressure. A possible mechanism is that the additive adsorbed on the film surfaces during polishing decreases the friction coefficient, hence the pad surface temperature gets lower with increasing the additive concentration. This difference in temperature was more remarkable for the higher concentration of abrasives. In addition, in-situ measurement of spindle motor was carried out during oxide and nitride polishing. The averaged motor current for oxide film was higher than that for nitride film, meaning the higher friction coefficient.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• 제18권9호
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• pp.803-809
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• 2005

Cerium ammonium nitrate (CAN) and nitric acid was used an etchant and an additive for Ru etching and polishing. pH and Eh values of the CAN and nitric acid added chemical solution satisfied the Ru etching condition. The etch rate increased linearly as the concentration of CAN increased. Nitric acid added solution had the high etch rate. But micro roughness of etched surfaces was not changed before and after etching, The removal rate of Ru film was the highest in $1wt\%$ abrasive added slurry, and not increased despite the concentration of alumina abrasive increased to $5wt\%$. Even Ru film was polished by only CAN solution due to the friction. The highest removal rate of 120nm/min was obtained in 1 M nitric acid and $1wt\%$ alumina abrasive particles added slurry. The lowest micro roughness value was observed in this slurry after polishing. From the XPS analysis of etched Ru surface, oxide layer was founded on the etched Ru surface. Therefore, Ru was polished by chemical etching of CAN solution and oxide layer abrasion by abrasive particles. From the result of removal rate without abrasive particle, the etching of CAN solution is more dominant to the Ru CMP.