| 摘要: | 近年來因氣候型態改變所造成的天災日益嚴重及頻繁，因此有關溫室氣體減量的議題日益受到重視。2005年2月16日京都議定書正式生效，CO2、CH4、HFCs、N2O、PFCs （Perfluorinated compounds, 全氟化物）及SF6等氣體正式列為管制項目。薄膜電晶體液晶顯示器 （Thin-Film Transistor-Liquid Crystal Display, TFT-LCD）製造業為國內繼半導體產業後政府大力扶植的重要產業之一，已逐漸成為跨國之大型企業。我國雖非京都議定書中附件一的規範國家，但國際間溫室效應氣體減量管制已成為趨勢，如何因應國際規範之衝擊並提升公司之競爭力，為當前重要之課題。依據國內台灣薄膜電晶體液晶顯示器產業協會(TTLA)會員承諾，2010年全氟化物(PFCs)排放目標為每生產1平方公尺面板所排放的碳當量，不能超過0.0335公噸，即排放目標值訂為0.0335 MTCE / m2，所以必須確切掌握TFT-LCD廠各世代之排放量是否符合要求。本研究乃依循ISO14064溫室效應氣體盤查規範進行盤查及驗證，統計2006~2009年之各世代製程溫室效應氣體排放推估，鑑定不同世代廠溫室氣體的排放源及排放強度後，並進一步探討各世代之差異性及PFCs減量之方向。研究結果顯示TFT-LCD之生產過程中其溫室效應氣體的主要排放源為用電(scope 2)所產生佔84%以上，其次為直接排放(scope 1)佔約16％，其中乾蝕刻 (Dry etching)製程的SF6 在scope 1約佔38%，再者為化學氣相沉積 (CVD, Chemical Vapor Deposition) 製程的NF3約佔27％。統計歷年每生產單位面積面板(投入量)其GHG平均排放量為0.191噸CO2 e/m2，其中3代製程PFCs之排放有逐年增加之趨勢，從2006年之0.1230噸CO2e/m2上升至2009年0.1913噸CO2e/ m2，4代製程以後單位面積CO2之排放皆在0.0062 ~0.0711噸CO2 e/m2，符合TTLA所定之0.0335 MTCE/m2(換算為0.1228噸CO2 e/m2)目標值，從生產耗能來看也是以3代製程最為耗能，平均每單位面積為587.61 kWh/ m2(約0.375噸CO2 e/m2)，隨製程世代之演進單位面積之耗電也逐漸降低，從4代製程315.22 kWh / m2降至7代製程130.98 kWh / m2。整體而言，現有3代製程PFCs減量效率須提升方可符合TTLA所承諾的0.0335 MTCE/m2目標值。 In recent years, natural disasters resulted from the changes of climatic conditions become more and more serious and frequent, and the issues of reducing the greenhouse gas emissions have received more attention. CO2、CH4、HFCs、N2O、PFCs (Perfluorinated compounds) and SF6 were officially considered as the greenhouse gases need to be regulated based on the Kyodo Protocol. The manufacturing industry of TFT-LCD (Thin-Film Transistor-Liquid Crystal Display), one of important industries fully supported by our government following the semiconductor industry, has gradually become major transnational business. The reduction and restriction of the emission of greenhouse gas is a tendency though we do not belong to the countries regulated by the Kyoto protocol. Therefore, how to confront the shocks of international enactments and to enhance the competitiveness of local industry is a major task needs to be addressed. From the promise by the members of TTLA, the equivalent amount of carbon for PFCs emission per faceplate product in 1 m2 can not exceed 0.0335 tons in 2010, i.e., the target is lower than 0.0335 MTCE/m2, which needs to check if the greenhouse gas emissions of various generation TFT-LCD plants meet this requirement. This research is motivated to calculate the amount of the greenhouse gases emitted from various generation TFT-LCD plants between 2006 and 2009 according to ISO14064. The difference between various generation plants and the strategies for reducing the amount of PFCs emission is further discussed after identifying the emission source and emission intensity of the greenhouse gas. The results indicate that the major emission source of greenhouse gases in TFT-LCD manufacturing processes is electric consumption (scope 2), which accounts for more than 84% of total emission. The next emission source is the direct emission (scope 1), accounting for 16 %, which includes 38 % emission of SF6 in dry etching process and the 27 % emission of NF3 in the chemical vapor deposition process. From the statistics over the years, the average GHG emission per unit area of faceplate is equal to 0.191 tons CO2 e/m2. Especially, the amount of PFCs emission in the process of third generation increases from 0.1230 tons CO2 e/m2 in 2006 to 0.1913 tons CO2 e/m2 in 2009. However, the CO2 emission per unit area of faceplate after the manufacturing process of fourth generation is among the range of 0.0062 ~ 0.0711 tons CO2 e/m2, which meets the TTLA’s target value of 0.0335 MTCE/m2 (i.e., 0.1228 tons CO2 e/m2). On the other hand, the process of third generation, consumes ca. 587.61 kWh/m2 (equal to 0.375 tons CO2 e/m2), is most energy-consuming from the view of energy-consumption per unit area of faceplate. In addition, the power- consumption per unit area of faceplate decreases gradually with the development of manufacturing generation, i.e., from 315.22 kWh/m2 in the third generation process to 130.98 kWh/m2 in the seventh generation process. In summary, the efficiency of PFCs reduction in the current process of third generation must be improved in order to reach the TTLA’s target of 0.0335 MTCE/m2. |
