• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.1164-1167
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• 2003

Recently CRT is getting flatted, As change of CRT trend from normal type to Flat type, the material of Shadow Mask was also changed from AK(Aluminum Killed) to Invar(Fe-Ni alloy) materials Until now we have used just AK(Aluminum Killed) for normal type TV(not flat type), but main raw material of shadow mask component was changed. . However recently Invar(Fe-Ni alloy) materials, which has advantage of Low Thermal Expansion and High Strength, has been developed as well as applying in mass production as CRT's trend has become more flat and fine pitch. As main raw material of shadow mask component was changed, conditions of process were changed. One of them, the importance of pre-etching process (assistant process for developing & etching) is improved because there are so many particles in the pre-etching bath because of Ni compounds. Since the solubility of Ni in pre-etching solvent is very low related to Fe's, so the compounds of Ni happen to make particles.(the solubility of Fe is twenty times Ni's) that particles happen to make process troubles and NG productions so to clear the particles we had to established high cost filtering system, but it is useless. As time goes by the quantity of particles (Ni compounds) was increased because of the capability of filtering system was not enough, the particles was produced continuous in bath, and it make quality problems. Hence we tried to develop the new pre-etching solution to remove the particles (Ni compounds) and to cost down the filtering system's running cost. But in improving the solution we discovered the new pre-etching solution made the PR developing better. In former solution there were three kinds of chemistry (COOH)2 , H2O2 , H2S04 .first the function of (COOH)2 is drilling the surface of Invar, during this mechanism Ni compounds occurred. Second the function of H202 is removing the PR fringe (half UV exposure zone on PR(PVA)), Third the function of H2S04 is the catalysis of (COOH)2 In those, (COOH)2 was the main reason to make the Ni compounds. So to improve the solutions we had to change (COOH)2 to the other material. the chemistry we improved was a complex chemistry based on H2S04 . after using this chemistry the particles problem was disappeared and there was another advantage cut down the PR fringe. The New solution made the function of H202 better so the PR developing improved. To be direct the catalyst of the new solution helped the H202. anyway First thing after change the solution the quality of shadow Mask for flat color TV was improved & the yield also improved. But the more important thing is how to control the new solution. So we accepted the new concept which was the degree of freshness. The degree of freshness is based on non-reacted solution which was 100% ( the degree of freshness) and calculated the melted Ni quantity as time goes by. So we made the gauging liner plot. In conclusion, many companies tried to make fine pitched Shadow Mask ,generally to make quality jump up it needed a lot of cost & persons .in this case the shift of core material made it possible.

• Journal of Korean Academic Society of Home Health Care Nursing
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• v.5
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• pp.20-31
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• 1998

The purpose of this study was to develop the framework of community-based home care nursing delivery system, and to examine the validity of it. For these, home care nursing study team of College of Nursing, Seoul National University has studied home care nursing system since September, 1996, and has operated home care center since August, 1997. This study has been supported by the Korean Sience Foundation. We organized Committee of rules, and Clinical specialist consultant group for more efficient running of the home care center. In nursing station, research assistant controlled general work, and 5 home care nurses were hired for home visiting. We developed the Standards for operations, that included criteria for clients, central supply system of nursing materials, central management of nursing care cost, advertisement, patient referral system, and so forth. In our center, 108 patients enrolled, and neurologic disorders including cerebrovascular accident, and cancer were the most prevailing diseases. We tried to overcome the limitations of hopital -based home care, and to provide more accessible, efficient, safe, and stable home care nursing. Therefore, we were referred clients from patients and families, public health care center, industries, as well as from hospitals. Meanwhile, we developed home care recording system and assessment-intervention algorithm for various diseases for quality control and standardization. Also, we did continuing education, and tried to detect problems and to find solutions by regular meeting between the committee of rules and home care nurses. As the results of this study, several limitations of operation were found. First, it was difficult to manage and communicate with the doctor in the emergency situation, Second, we spent too much time for trasnsportation, because only five nurses covered all areas of Seoul and nearby cities. Third, preparation for special care of home care nurses were lacked. Forth, criteria for termination of care and frequency of home visit were ambiguous. Fifth, some difficulties were found in retrospective payment system. And finally, interconnection with home care machinery company were needed. Strategies for solving these problems were suggested.