• Proceedings of the Korea Air Pollution Research Association Conference
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• 2001.11a
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• pp.331-332
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• 2001

CFCs는 가정 제품과 공업적 과정에서 발포제와 냉매제로 오랜 기간 사용되었다. 1974년, CFCs는 Molina와 Rowland에 의해 성층권 오존의 고갈 요인으로 인식되었고, 최근에는 지구 온난화의 기여물질로써 관련되어 지고 있다. CFCs의 세계적인 생산은 Montreal 의정서와 그 개정안에 의해 점차 폐지되었고, 대체 물질로 HCFCs와 HFCs가 과도하게 사용되고 있다. 수소의 존재는 대체 물질의 대류권 산화를 가능하게 했고, 대체로 성층권에 영향을 미치지 않는다. (중략)

• Analytical Science and Technology
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• v.6 no.5
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• pp.521-530
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• 1993

According to the Montreal Protocol, CFC 113, one of the ozone-depleting substances, will be prohibited to use as a cleaning solvent essentially in the electronic industry. Therefore, the development of the alternative cleaning solvents to CFC 113 is being accelerated. A number of the alternative cleaning solvents are avialable on the market. The alternatives of Axarel 32(DuPont), Cleanthru 750H(KAO Chemical), and EC-Ultra(Petroferm) are chosen for the comparison of cleaning performance with CFC 113. The test methods for measuring the cleaning performance were composed of the measurement of the physical properties, the experiments on the material compatibility with cleaning solvents, the measurement of the evaporation rate, and finally the experiments of the removal efficiency. Normally the basic physical properties of the alternatives had higher boiling points, viscosity and surface tension, which were quite different to those of CFC 113. In terms of solubility of rosin-based flux, the solubilities of abietic acid (nonpolar organic) were similar, but those of the activator (polar organic) in the alternatives were better than CFC 113. The evaporation of the alternatives was very slow, compared to CFC 113, which had much lower boiling point. All the cleaning solvents showed the good material compatibility with FR4 and Cu-coated PCB. The better removal efficiencies of abietic acid were obtained when using the ultrasonic mechanical energy over the dipping method. The experiments also indicated the very slow-eavaporating solvent was not desirable with the dipping cleaning method, and the differences in the removal efficiency of the alternatives with the ultrasonic cleaning method were negligible. Among the alternatives, the overall cleaning performances were obsorved as almost similar. Before selecting the ultimate cleaning solvent, the application of cleaning machine, environmental issues, and economics are simultaneously considered with the cleaning performance.

• Electrical & Electronic Materials
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• v.9 no.3
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• pp.240-245
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• 1996

Non-ozone layer destructive Chlorofluorocarbon(CFC) altematives(CHCIF$_{2}$ and $C_{2}$H$_{2}$F$_{4}$) have been initially used for laser-induced thenrmochemical etching of GaAs. High etching rate up to 188.mu.m/sec and an aspect ratio of 2.7 have been achieved by a single scan of laser beam, respectively. The etching rate at constant ambient gas pressure was found to saturate for beam power. The chemical compositions of the reaction products deposited on the etched groove were measured by Auger electron microscopy(AES). Etched profile, depth and width were observed by scanning electron microscope(SEM).

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.25 no.1
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• pp.53-66
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• 1996

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.21 no.2
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• pp.105-142
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• 1992

• Bulletin of Korea Environmental Preservation Association
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• v.20 no.6
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• pp.4-9
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• 1998

• Bulletin of Korea Environmental Preservation Association
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• v.18 no.10
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• pp.60-65
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• 1996

• Journal of the korean Society of Automotive Engineers
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• v.15 no.2
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• pp.23-35
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• 1993

1. 몬트리올 의정서. 2. 우리나라 오존층보호 규제. 3. 특정물질 사용감축 방안. 4. 우리나라 자동차업계의 대체냉매 에어컨 개발동향

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.21 no.3
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• pp.174-188
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• 1992

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 2002.04a
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• pp.247-248
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• 2002

CFCs는 가정제품과 공업의 생산과정에서 발포제와 냉매제로 오랜 기간 사용되었다. 1974년, CFCs는 Molina와 Rowland에 의해서 성층권 오존의 고갈 요인으로 인식하게 되었고, 최근에는 지구 온난화의 기여물질로써 사회적 관심이 증가하였다. CFCs의 세계적인 생산은 Montreal 의정서와 그 개정안으로 인해 점차 감소하면서 사용이 폐지되었고, 대체 물질로 HCFCS와 HFCs가 사용되고 있다. 대류권에서 HCFCs와 HFCs는 hydroxyl radicals에 의해 산화되고, 최종 분해산물로 무기산, 염, HF, $CO_2$, HC와 Trifluoroacetic acid(TFA)가 생성된다. (중략)