化學液槽車灌裝風險及最佳化對策研究 - 以半導體廠例

Abstract

在半導體晶圓製造的過程中須使用大量的化學品，以滿足半導體廠生產不中斷的特性。因此，半導體廠必須利用化學品槽車，以灌裝方式來補充製程所需化學品及清運相關廢液。而化學液槽車作業流程作業中，因其具有危害且量大的特性，一旦有大量化學品洩漏或充填錯誤發生，將造成人員安全問題或作業環境汙染，甚至可能導致生產中斷及環保問題。 本論文研究主要是以半導體廠化學液槽車灌裝進行安全風險評估，其範圍包含化學品原物料槽車入廠灌充及廢液回收裝填作業，透過實地的作業觀察進行工作安全分析及風險評估，了解半導體廠槽車作業的灌裝安全風險及現有控制。同時收集近10年內之半導體廠發生的槽車填充安全意外案例，根據分析的結果，提供有效的安全預防措施建議，透過實務的改善經驗，提供其他業界參考，期能改善化學液槽車灌裝作業安全，進而發展出最佳化之化學液槽車灌裝作業安全對策。 研究結果顯示: 化學液槽車作業步驟主要為：槽車進廠、定位、管路銜接、填充加藥、管路脫離及離廠等作業流程。在槽車的進出廠及定位危害已被有效控制，但在管路銜接、填充加藥過程、管路脫離等作業則仍須改善，以降低相關偶發之工安意外事件。改善措施包含針對加藥管路銜接及脫離步驟可能造成之人員墜落預防、管路銜接錯誤再增設fail-safe 設施控制、進行作業區hot-zone之管制、加強人員防護具(PPE)保護、及改善管路脫離前之殘液/殘氣排除效能，以避免脫離加藥管路作業時的殘液洩漏風險。研究結果同時顯示70%的實際槽車作業安全意外案例，係發生在廢液的槽車灌裝作業。因此，半導體廠應更加特別注意有關廢液回收槽車之安全要求及管理。

For semiconductor wafer continuous production process, all Fabs need a great volume, and reliable, uninterrupted chemical supply system. Therefore, Semiconductor plants have to use liquid chemical lorry for the production line and also to ship away big volume of waste liquid chemical. And during liquid chemical loading/unloading, because of the hazard and volume, in case of spill or incorrect loading/unloading to mix incompatible chemicals, the consequences could be serious human health/safety impact, environmental pollution, or even production interruption. This study majorly focus on site observation and risk analysis of semiconductor plant liquid chemical lorry loading/unloading operation, which covers raw chemical lorry unloading into tank and waste chemical unloading into lorry. With site observation and risk analysis, we understand the lorry operation risk and existing control measures and we collected abnormal events over the past 10 years related to lorry loading/unloading operation, and carried out an analysis to come up with an effective prevention recommendation, and through practical improvement experience, we can share with other industries/plants; hopefully, we can improve all chemical lorry loading/unloading operation and ensure lorry related operation accuracy and safety. The main stages of the chemical lorry operation is lorry driving in, parking/positioning, piping connecting, unlading/loading, piping disconnecting, lorry driving out. At the stages of lorry driving in and parking/positioning of which risks are effectively controlled, however, piping disconnecting, loading/unloading, and piping disconnecting stages need to be improved to minimize the risks or abnormal events. The improvement includes; operator’s fall prevention during piping disconnecting/connecting; adding fail safe mechanism to prevent incorrect piping connecting; the control of the hot zone; PPE enhancement; and the effective purge of chemical liquid/vapor residue prior to piping disconnecting to minimize the chemical spill risks. The study also shows that about 70% of lorry related events were occurred during liquid waste chemical lorry loading/unloading. So we should pay more attention to waste chemical lorry safety management.